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Zhang, Su. "Quantitative risk assessment under multi-context environments." Diss., Kansas State University, 2014. http://hdl.handle.net/2097/18634.
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Doctor of Philosophy<br>Department of Computing and Information Sciences<br>Xinming Ou<br>If you cannot measure it, you cannot improve it. Quantifying security with metrics is important not only because we want to have a scoring system to track our efforts in hardening cyber environments, but also because current labor resources cannot administrate the exponentially enlarged network without a feasible risk prioritization methodology. Unlike height, weight or temperature, risk from vulnerabilities is sophisticated to assess and the assessment is heavily context-dependent.
Existing vulnerability assessment methodologies (e.g. CVSS scoring system, etc) mainly focus on the evaluation over intrinsic risk of individual vulnerabilities without taking their contexts into consideration. Vulnerability assessment over network usually output one aggregated metric indicating the security level of each host. However, none of these work captures the severity change of each individual vulnerabilities under different contexts.
I have captured a number of such contexts for vulnerability assessment. For example, the correlation of vulnerabilities belonging to the same application should be considered while aggregating their risk scores. At system level, a vulnerability detected on a highly depended library code should be assigned with a higher risk metric than a vulnerability on a rarely used client side application, even when the two have the same intrinsic risk. Similarly at cloud environment, vulnerabilities with higher prevalences deserve more attention. Besides, zero-day vulnerabilities are largely utilized by attackers therefore should not be ignored while assessing the risks. Historical vulnerability information at application level can be used to predict underground risks. To assess vulnerability with a higher accuracy, feasibility, scalability and efficiency, I developed a systematic vulnerability assessment approach under each of these contexts.
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Juarez, Garcia Hugon. "Multi-hazard risk assessment : an interdependency approach." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/27271.
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This research began with the Joint Infrastructure Interdependencies Research Program (JIIRP). JIIRP was part of an effort by the Government of Canada to fund research to develop innovative ways to mitigate large disaster situations. An interdependency simulator (I2Sim) was developed in the University of British Columbia through this project. This tool was developed to take into account the dynamic changes of the functional conditions of any given system.
This thesis makes two major contributions to the capability of the simulator’s methodology, to handle seismic events and events that affect dense concentrations of people. The distinguishing characteristic of an earthquake event can affect the city and all the surrounding regions, causing damage to all lifeline systems. In its original form, I2Sim could model the damage and impact of each system on its own, but was unable to account for the effects of all other systems. The interdependency between systems is a crucial element for determining the impact of an earthquake and the time for recovery. The methodology proposed here can be used to measure Interdependencies and Resiliency in a region.
Two cases were studied and implemented to test the methodology and the simulator. The first one was an earthquake hazard in a relatively small region (UBC Campus) in which the interdependencies and resiliency would be revealed to the emergency managers of UBC Campus; the second one, was a localized event in a massive sporting event (Winter Olympics in Vancouver), a black out in a Football Stadium that caused an uncontrolled egress, and related casualties due to a collapsing stage and the evacuation process were modelled.
With the methodology and the simulator (I2Sim) it is possible to build up Region models, Disaster Scenarios, Objective Functions and Emergency Planning; and these, along with Interdependency and Resiliency calculations, will help in the preparedness, planning, response and recovery phases of any disaster.
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Bani-Mustafa, Tasneem. "Multi-Hazards Risk Aggregation Considering the Trustworthiness of the Risk Assessment." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC096.
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Cette thèse de doctorat aborde le problème de l'agrégation de risques multiple (MHRA), qui vise à agréger les risques estimés pour différents contributeurs. La pratique actuelle de la MHRA est basée sur une sommation arithmétique simple des estimations de risques. Cependant, ces estimations sont obtenues à partir de modèles EPS (Estimation Probabiliste de risque) qui présentent des degrés de réalisme différents liés à différents niveaux de connaissances. En ne prenant pas en compte ces différences, le processus MHRA pourrait conduire à des résultats trompeurs pour la prise de décision (DM). Dans cette thèse, un cadre structuré est proposé afin d’évaluer le niveau de réalisme et de confiance dans les évaluations de risques et de l’intégrer dans le processus de MHRA. Ces travaux ont permis : (i) Une identification des facteurs contribuant à la fiabilité de l'évaluation des risques. Leurs criticités sont analysées afin de comprendre leur influence sur l’estimation des risques; (ii) Un cadre hiérarchique intégré est développé pour évaluer la confiance et le réalisme de l'estimation de risque, sur la base des facteurs et des attributs identifiés en (i); (iii) Une méthode basée sur un modèle réduit est proposée pour évaluer efficacement la fiabilité de l'évaluation des risques dans la pratique. Grâce à cette méthode, le nombre d'éléments pris en compte dans l'évaluation initiale des risques peut être limité. (iv) Une technique qui combine la théorie de Dempster-Shafer et le processus de hiérarchie analytique (DST-AHP) est appliquée au modèle développé. Cette technique permet d’évaluer le niveau de réalisme et confiance -dans l’analyse de risque- en utilisant une moyenne pondérée des attributs: la méthode AHP est utilisée pour calculer le poids des attributs et la méthode DST est utilisée pour tenir compte de l'incertitude subjective dans le jugement des experts dans l'évaluation des poids; (v) Une technique de MHRA est développée sur la base d'un modèle de moyenne bayésienne afin de surmonter les limites de la pratique actuelle de MHRA qui néglige le réalisme et confiance dans l'évaluation de chaque contributoire de risque; (vi) Le modèle développé est appliqué sur des cas réels de l'industrie des centrales nucléaires<br>This PhD thesis addresses the problem of Multi-Hazards Risk Aggregation (MHRA), which aims at aggregating the risk estimates from Probabilistic Risk Assessment (PRA) models for the different contributors. The current practice of MHRA is based on a simple arithmetic summation of the risk estimates. However, the risk estimates are obtained from PRA models that have different degrees of trustworthiness, because of the different background knowledge they are based on. Ignoring this difference in MHRA could lead to misleading results for Decision-Making (DM). In this thesis, a structured framework is proposed to assess the level of trustworthiness, which risk assessment results are based on and to integrate it in the process of MHRA. The original scientific contributions are: (i) Factors contributing to the trustworthiness of risk assessment outcomes are identified and their criticalities are analyzed under different frameworks, to understand their influence on the risk results; (ii) An integrated hierarchical framework is developed for assessing the trustworthiness of risk analysis, based on the identified factors and related attributes; (iii) A reduced order model-based method is proposed to efficiently evaluate the trustworthiness of risk assessment in practice. Through the reduced-order model, the proposed method can limit the number of elements considered in the original risk assessment; (iv) A technique that combines Dempster Shafer Theory and the Analytic Hierarchy Process (namely, DSTAHP) is applied to the developed framework to assess the trustworthiness by a weighted average of the attributes in the framework: the AHP method is used to derive the weights of the attributes and the DST is used to account for the subjective uncertainty in the experts’ judgments for the evaluation of the weights; (v) A MHRA technique is developed based on Bayesian model averaging, to overcome the limitations of the current practice of risk aggregation that neglects the trustworthiness of the risk assessment of individual hazard groups; (vi) The developed framework is applied to real case studies from the Nuclear Power Plants (NPP) industry
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Chiu, Kenneth. "Generalized Gaussian covariance analysis in multi-market risk assessment." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/35449.
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Gehl, P. "Bayesian networks for the multi-risk assessment of road infrastructure." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1546080/.
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The purpose of this study is to develop a methodological framework for the multi-risk assessment of road infrastructure systems. Since the network performance is directly linked to the functional states of its physical elements, most efforts are devoted to the derivation of fragility functions for bridges exposed to potential earthquake, flood and ground failure events. Thus, a harmonization effort is required in order to reconcile fragility models and damage scales from different hazard types. The proposed framework starts with the inventory of the various hazard-specific damaging mechanisms or failure modes that may affect each bridge component (e.g. piers, deck, bearings). Component fragility curves are then derived for each of these component failure modes, while corresponding functional consequences are proposed in a component-level damage-functionality matrix, thanks to an expert-based survey. Functionality-consistent failure modes at the bridge level are then assembled for specific configurations of component damage states. Finally, the development of a Bayesian Network approach enables the robust and efficient derivation of system fragility functions that (i) directly provide probabilities of reaching functionality losses and (ii) account for multiple types of hazard loadings and multi-risk interactions. At the network scale, a fully probabilistic approach is adopted in order to integrate multi-risk interactions at both hazard and fragility levels. A temporal dimension is integrated to account for joint independent hazard events, while the hazard-harmonized fragility models are able to capture cascading failures. The quantification of extreme events cannot be achieved by conventional sampling methods, and therefore the inference ability of Bayesian Networks is investigated as an alternative. Elaborate Bayesian Network formulations based on the identification of link sets are benchmarked, thus demonstrating the current computational difficulties to treat large and complex systems.
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Hahn, Lukas [Verfasser]. "Quantitative assessment of multi-year non-life insurance risk / Lukas Hahn." Ulm : Universität Ulm, 2019. http://d-nb.info/119313966X/34.
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Hahn, Lukas Josef [Verfasser]. "Quantitative assessment of multi-year non-life insurance risk / Lukas Hahn." Ulm : Universität Ulm, 2019. http://d-nb.info/119313966X/34.
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Pham, Hung Vuong <1988>. "Multi-risk assessment of freshwater ecosystem services under climate change conditions." Doctoral thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/17841.
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The aim of this work is to develop a multidisciplinary approach to (i) understand the dynamics of freshwater-related ecosystem services (ES); (ii) quantify the conjoined effects of climate and land use change on these ES; (iii) evaluate the effectiveness of different management scenarios; and (iv) provide appropriate indicators to support the identification of proper practices to improve ES management at the local level. First, we reviewed the complex effects of climatic and non-climatic drivers on the supply and demand of freshwater ecosystem services. Based on the literature, we proposed a conceptual framework and a set of indicators for assessing the above-mentioned impacts due to global change, i.e. climate change and human activities. Then, we checked their applicability to the provisioning services of two well-known case studies, namely the Po River basin (Italy) and the Red River basin (Vietnam). Second, we developed an integrated modeling approach to assess the conjoined impacts of land use and climate changes on the potential ecosystem services (i.e. water yield and nutrients retention) until 2050. This integrated approach is applied to the Taro river basin in the context of the PROLINE CE project, which focused on the sustainable use of freshwater in an integrated land use management approach. Finally, we integrated Bayesian Networks in ecosystem service model which enables identification of risks of human interaction on ecosystem, trade-offs among ecosystem services, and evaluation of different management scenarios. The outcomes of this work could be a valuable support to identify and prioritize the best management practices for sustainable water use, balancing the tradeoffs among services.
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LARI, SERENA. "Multi scale heuristic and quantitative multi-risk assessment in the Lombardy region, with uncertainty propagation." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7550.
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In this thesis, some methodologies for multi-risk assessment are presented, that
can be applied to regional or local scale. At the local scale, the problem of uncertainty
propagation in risk assessment is treated, testing different methodology for calculation.
The work is organised in four parts:
1. Multi risk analysis at the regional scale in Lombardy (PRIM project, 2007).
The methodology integrates information with different degree of accuracy
into an indicator based approach, in order to develop a regional scale multirisk
assessment and to identify “hot spot” risk areas for more detailed
analysis. Eventually, the sensitivity of weights is investigated, and the effect
on risk assessment of different individual attitudes and perception (i.e., expert,
social, political, risk aversion).
2. Quantitative multi risk assessment (QRA) at the local scale on the hot spots,
for lower Valtellina and the area of Brescia and lower Val Trompia, Val
Sabbia, and Valcamonica. The methodology is based on the use of historical
data and modelling to assess for each threat the expected number of casualties
and the expected economic damage.
3. Quantitative risk assessment (QRA) for floods, earthquakes and industrial
accidents in the area of Brescia (420 km2), with uncertainty propagation
analysis. Frequency-damage curves were calculated. Three methods were
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used and compared to calculate the uncertainty of the expected economic
losses: Monte Carlo Simulation, First Order Second Moment approach, and
Point Estimate.
4. Realization of a tool based on a system of indicators aimed at assigning a
priority for the realization of new mitigation works, at the evaluation of
efficacy of existent works, and at the comparison of different alternatives for
the same risk scenario. Indicators are referred to the risk scenario, to the most
recent and most significant event occurred in the analysed area, to the
planning stage of the work, and to the technical characteristics of realization
and maintenance of the work itself.
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Terzi, Stefano <1988>. "Multi-risk assessment within the context of climate change in mountain regions." Doctoral thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/17837.
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Mountain regions are facing multiple impacts due to climate change and anthropogenic activities. While shifts in precipitation and temperature are affecting the available water, current water demand for economic activities still rely on large quantity of water making mountain regions particularly susceptible to water scarcity.
This conditions call for innovative methodologies able to represent complex dynamics of human-natural systems to understand and adapt to future climate change impacts.
For these reasons, a literature review considered five innovative modelling approaches (Bayesian networks, agent-based models, system dynamic models, event and fault trees, and hybrid models), exploring their advantages and limitations and providing a roadmap for methodological and technical implementation of multi-risk assessments.
Among these methodologies, system dynamics modelling (SDM) was chosen and applied to explore multiple interactions and feedback loops associated to hydrological processes and human demands in the Noce river catchment in the Province of Trento (Italy).
Firstly, this study explored the vulnerability of a major reservoir in the Noce catchment considering the current situation and future climate change effects influencing the water stored and flow diverted to reservoir hydropower turbines and the amount of water remaining for other activities. By doing so, the aim was to test and demonstrate a probabilistic SDM assessment expanding the information coming from a hydrological model for quick and effective considerations on reservoir future conditions.
Secondly, the SDM model was extended to different parts of the overall Noce catchment characterizing the hydropower water demand from other reservoirs, the agriculture demand for apples production and domestic water demand. By doing so, the aim was to compare the available water in future climate change scenarios with the water demand, resulting in vulnerable future conditions and multiple impacts on the selected sectors.
Finally, such assessment aimed to identify critical states coming from a systemic perspective of water availability and water demand for each sub-catchment. The study discussed possible adaptation measures aimed to inform decision makers in order to prepare to future conditions of tackle climate-related water scarcity.
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Aksha, Sanam Kumar. "Assessing vulnerability and multi-hazard risk in the Nepal Himalaya." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/85864.
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Communities around the world are encountering unprecedented rates of change due to population growth, land use change, development, and increased social vulnerability to natural hazards. Understanding how physical processes and human vulnerability to natural hazards interact is a primary objective of researchers, policy makers, and disaster risk reduction practitioners in order to combat increases in natural hazard frequency and intensity.
Nepal, a landlocked mountainous country spanning the central Himalayan region, has about 28 million inhabitants in 147,181 square kilometers. Nepal is exposed to a multitude of natural hazards, requiring individuals and communities to interact with and make decisions on risk acceptability on a day-to-day basis. In many cases, Nepal's geographic location, available resources (human, economic, and capital), and limited government capacity coalesce to turn natural hazards into disasters, resulting damaged infrastructure, economic disruptions, and death.
This dissertation evaluates the geographic distribution of natural hazard mortality, quantifies social vulnerability to natural hazards, and models multi-hazard risk in the data deficient environment of Nepal. Chapter 1 conceptualizes relevant terms such as natural hazards, disaster, vulnerability, and risk before discussing the challenges associated with multi-hazard risk assessment in Nepal. Chapter 2 evaluates the spatial and temporal distribution of natural hazard mortalities at the village level using a publicly available disaster database. Results reveal that landslides were the deadliest disasters between 1971-2011. Chapter 3 identifies major social factors and processes that contribute to the vulnerability of individuals and communities using census data. Adapting the Social Vulnerability Index (SoVI) method developed for the US context, this chapter investigates the spatial distribution and clustering of various social vulnerabilities across the country. 'Renter and Occupation', 'Poverty and Poor Infrastructure', and 'Favorable Social Conditions' are three major components that influence social vulnerability in Nepal. Results indicate an interesting regional difference: the eastern and central Tarai are more vulnerable than western Tarai, whereas the eastern Hills and Mountains are less vulnerable than western Hills and Mountains. In Chapter 4, a model of risk from multiple natural hazards in the city of Dharan, Nepal, is presented. Freely available geospatial data in combination with socio-economic data collected from local government and secondary sources are used. Multi-hazard risk assessment is data intensive and requires considerable financial and human resources, which are lacking in Nepal. Results show that geospatial modeling techniques can be used to fill the gap and assist local officers and emergency managers in risk management.
Cumulatively, this work offers new insights on natural hazards, vulnerability, risk, the use of geospatial technologies, and their inter-relationships. Research findings advance scholarly understandings of multi-hazard risk in general and particularly in the Nepali context. Additionally, this work is valuable to disaster practitioners who seek to implement more effective disaster risk reduction programs and policies.<br>Ph. D.<br>Natural hazards are earth system processes that pose threats to people and have the capacity to disrupt social and ecological processes. Thus, a consideration of both physical and social dimensions is required to better understand natural hazards. This research evaluates social factors and processes that have significant roles in enhancing the vulnerability of individuals and communities. First, this dissertation explores spatial and temporal patterns of natural hazard fatalities at the village level in Nepal. Research findings identified that landslides were the highest contributor to natural hazard fatalities from 1971-2011. Second, this dissertation assesses which social factors and processes contribute most to social vulnerability in Nepal. Additionally, the spatial distribution and clustering of social vulnerability is explored. Finally, geospatial modeling was performed to analyze cumulative risk to floods, landslides, and earthquakes in the municipality of Dharan, Nepal.
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Luria, Paolo. "Evaluating a multi-criteria model for hazard and risk assessment in urban design." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/32565.
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The aim of this research is to test a decisional aid model - the Analytic Hierarchy Procedure (AHP) - in risk assessment for development of an urban area. The Port Authority of Venice commissioned the Regional Environmental Protection Agency (ARPAV) to carry out an estimation of major industrial hazards in Porto Marghera, an industrial estate near Venice (Italy), via Quantitative Risk Analysis (QRA). However, this model only provided a list of individual quantitative risk values, related to single locations. Therefore, there was both a need and an opportunity to introduce a decision aid model, which could take into account the geographic distribution of risk, the quantification of intangible factors and the analysis of possible future developments. The experimental model, through a series of trade -off comparisons, encouraged the use of expert opinions in conjunction with traditional quantitative analysis, enabling the decision maker to generate quantitative data on risk assessment from a series of subjective, qualitative assessments. It was also a major result to bring together complementary skills and expertise from different disciplines in a wide and clear collaborative research project.
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Weyer, Vanessa Derryn. "Surface-strip coal mine rehabilitation risk assessment : the development of an integrated rehabilitation risk assessment model for use in South Africa and Australia." Thesis, University of Pretoria, 2020. http://hdl.handle.net/2263/77899.
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Surface-strip coal mine rehabilitation planning in South Africa and Australia is immature.
Rehabilitation risk assessment, despite being advocated by leading practice guidelines
and in some instances by legislation, is conducted with minimum requirements often met
by rehabilitation professionals. Specialist data is gathered during mine approval and for
the environmental impact assessment process. However, the focus of this is toward
assessing mining impacts and not for rehabilitation risk assessment. Quantitative,
integrated, multi-disciplinary rehabilitation risk assessment is seldom undertaken. This
thesis provides a methodology towards the development of a quantitative, integrative,
multi-disciplinary rehabilitation risk assessment model. Its purpose being to 'profile'
surface-strip coal mine sites, in terms of their rehabilitation risk and potential for
rehabilitation failure, from the outset of mine operations, with adjustments possible
progressively during mine operations. The methodology was developed by first
reviewing techniques suitable for the development of the model, as well as techniques
developed by others. Bayesian networks (BN) were found to be the most suited. A R2AIN
framework was then provided as a process towards developing several BN risk event
models that can amalgamate to form a synthesis rehabilitation risk assessment model. A
case study soil compaction BN model was used to demonstrate the framework in South
Africa and Australia. The case study showed that it is possible to integrate and quantify
rehabilitation risk, and most importantly to segregate risk into discrete contributing multidisciplines
for analysis. Risk percentages can be calculated per multi-discipline, per mine
phase, per site, to aid site risk ‘profiling’. It is recommended that further risk event BN
models be prioritised for development and that a rehabilitation risk assessment model be
developed to synthesise these into one model. This will require continuous improvements
in the method, to build confidence, including extensive risk event and synthesis BN
model evaluation and testing; improved BN input node states and values; and
simplification of the conditional probability table construction method. Adaptation to
other mining types, development activities and other regions should be investigated, as
well as spatial linkages to geographic information systems. This research contribution
improves upfront mine rehabilitation planning and decision making, providing improved
tools and techniques than what currently exist.<br>Thesis (PhD)--University of Pretoria, 2020.<br>Geography, Geoinformatics and Meteorology<br>PhD<br>Unrestricted
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Lozoya, Azcárate Juan Pablo. "Multi-risk assessment and users' perception: a futher step towards ecosystem-based beach management." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/113675.
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This thesis deals with the need to move towards a holistic, truly integrated and ecosystem-based beach management that allows a sustainable use of these systems within the socio-ecological paradigm. However, the scarcity of frameworks for such management has been identified as a major constraint. The goal of this thesis was to apply and develop a set of methodologies based on the introduction of the Ecosystem Approach principles to beach management. These tools would be part of the Ecosystem Based Management System (EMBS), a novel formal system of public good management developed for coastal and marine environments. The study was conducted along the Costa Brava, a coastal area highly affected by tourism that alternates urban and natural beaches. The work starts providing a brief description of major paradigms of environmental management, with special emphasis on beach management. It also discusses the situation in Spain and its differences with main European policies in this area. Results confirm the need of an integrated and holistic beach management based on "sources" and not only on "resources", and the urgency of developing tools that could be really implemented. The main contribution of this thesis is a methodological framework based on multi-hazards risk assessment, which allows managers to identify and prioritize the main hazards potentially disturbing the beach and affecting existing ecosystem services. Thus managers could adapt their strategies according to their priorities, visions and resources. This methodology was validated in S¿Abanell beach, where 7 hazards and 6 ecosystem services were identified. In this thesis, beaches have been analyzed as socio-ecological systems, emphasizing the social dimension of the system that is not always considered. In this dissertation the users¿ perceptions have been analyzed as a feedback of management measures, comparing them in two antagonistic settings: an urban (S¿Abanell) and a natural-protected beach (St Pere Pescador). Learning from previous measures, this feedback should improve the setting of management according to the characteristics of each beach, increasing its adaptability and avoiding its homogenisation. Natural attributes were a priority in the protected setting, while services were highlighted in the urban one. But significant differences were not as important as would be assumed a priori. This homogenization in users¿ perceptions could be due to the scarce information-education provided to users on the protected beach, to the management that not really emphasizes the natural attributes of this beach, and to the strong influence of the surroundings with a long tradition of mass tourism. Achieve an effective implementation of integrated management has been also cited as a critical need. In this sense, this study has addressed a key component by means of an institutional analysis, identifying responsible authorities and key officers in charge of beach management. For 8 beaches of the Costa Brava the assessment identified duplications and absences in the management of key processes underlying main beach functions. Likewise, it showed the great diversity and complexity of the current beach management structures of this zone. The results confirmed the prioritization of the recreational function of the beach, with beach management almost restricted to the summer season. Concerning management structures, even if the three major Spanish legal scales were clearly recognized, a myriad of layouts have been identified within Municipalities. Within the current model, different aspects of the same system are managed in isolation, by different authorities with different objectives. Hence, beach management is fragmented and based on responsibilities, hindering the eventual implementation of new management plans. Thus, this dissertation aims to contribute to the development of a pathway in order to achieve a holistic, truly integrated and ecosystem-based beach management model.<br>Esta tesis se enmarca en la urgente necesidad de avanzar hacia una gestión de playas holística, verdaderamente integrada y basada en los ecosistemas, permitiendo un uso sostenible de estos sistemas dentro del actual paradigma socio-ecológico. Uno de los principales obstáculos para ello ha sido la escasez de herramientas que puedan ser realmente implementadas. El objetivo de la tesis fue aplicar y desarrollar este tipo de metodologías introduciendo los principios del enfoque ecosistémico en la gestión de playas. Estas herramientas se integrarían en el Ecosystem Based Management System (EBMS), un sistema de gestión de bienes públicos actualmente en desarrollo para entornos costeros y marinos. El estudio se desarrolló en la Costa Brava, una región tradicionalmente turística que alterna playas urbanas y naturales. Este trabajo comienza describiendo la evolución de los principales paradigmas de la gestión ambiental, con énfasis en la gestión de playas. Se analiza además el caso de España y sus principales diferencias con las políticas europeas en esta materia. Los resultados confirman la necesidad de una gestión integrada basada en “las fuentes” y no sólo en “los recursos”, y de metodologías que puedan ser implementadas. La principal contribución de esta tesis es una metodología basada en la evaluación de riesgos por múltiples eventos, que permite identificar y priorizar las principales amenazas que pueden perturbar el sistema y los servicios ambientales que este brinda. Así los administradores podrían adaptar su gestión según sus prioridades, visiones y recursos. Esta metodología fue validada en la playa de S´Abanell, identificándose y cuantificándose siete eventos de riesgo y seis servicios ambientales. En esta tesis las playas han sido analizadas como sistemas socio-ecológicos, destacando la dimensión social del sistema que no siempre es considerada. Como feedback para la gestión, en este trabajo se analizaron y compararon las percepciones de los usuarios en dos playas antagónicas, una urbana (S´Abanell) y una natural protegida (St Pere Pescador). Este feedback permite aumentar la adaptabilidad de la gestión, ajustándola a las características de cada playa y evitando su homogeneización. Los atributos naturales fueron una prioridad en el escenario protegido, mientras que los servicios lo fueron en el urbano. Existieron diferencias significativas pero no fueron tan importantes como se hubiera asumido a priori. Esta homogeneización de las percepciones podría deberse a la escasa información/educación en la playa protegida, a una gestión en dicha playa que no destaca los atributos naturales como debería, y a una fuerte influencia de un entorno con gran tradición de turismo masivo. No lograr una efectiva implementación de la gestión integrada también ha sido un obstáculo, siendo esenciales las estructuras de gestión. En esta tesis se obtuvo un diagnóstico de las autoridades a cargo de la gestión de playas en 8 Municipios de la Costa Brava. Se realizó un análisis institucional analizando duplicaciones y ausencias en la gestión de los procesos que sustentan las principales funciones de la playa, así como la complejidad de sus estructuras. Los resultados confirmaron la priorización de la función recreativa, restringiendo la gestión de playas únicamente al verano y a la temporada de baño. Además de las tres principales estructuras jurídicas responsables de la gestión de playas en España, se identificaron una infinidad de diseños de estructura de gestión a nivel de Municipios. Bajo el actual modelo de gestión, aspectos de un mismo sistema se analizan por separado y en solitario, por diferentes autoridades con diferentes objetivos. La gestión esta fragmentada y basada en competencias, lo que obstaculiza la eventual aplicación de nuevos modelos integrados. De esta manera, esta tesis pretende contribuir al desarrollo de una vía que permita alcanzar un modelo de gestión de playas holístico, verdaderamente integrado y basado en los ecosistemas.
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Asadi, Esmaeel. "RISK-INFORMED MULTI-CRITERIA DECISION FRAMEWORK FOR RESILIENCE AND SUSTAINABILITY ASSESSMENT OF BUILDING STRUCTURES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=case1575381834399844.
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Liu, Baoyin. "Modelling multi-hazard risk assessment : a case study in the Yangtze River Delta, China." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/11544/.
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Multi-hazard risk assessment (MHRA) has become a major concern in the risk study area, but existing approaches do not adequately meet the needs of risk mitigation planning. The main research gap in the existing approaches was identified that they cannot consider all hazard interactions when calculating possible losses. Hence, an improved MHRA model, MmhRisk-HI (Model for multi-hazard Risk assessment with a consideration of Hazard Interaction), was developed. This model calculates the possible loss caused by multiple hazards, with an explicit consideration of interaction between different hazards. A more complete perspective, the regional disaster system perspective, was selected as the basic theory, and two categories of multi-hazard risk expressions were combined in the model construction. Hazard identification, hazard analysis, hazard interaction analysis, exposure analysis and vulnerability analysis are the five basic modules of the developed model. The concept of hazard-forming environment was introduced into the MHRA research as the basis for hazard identification, hazard analysis, and hazard interaction analysis. The methods used for exposure analysis depend on the scale of the region to be addressed and the assessment units. A Bayesian Network was adopted to calculate the loss ratio in the vulnerability analysis. This developed model was applied into the Yangtze River Delta (YRD) and validated by comparison with an observed multi-hazard sequence. The validation results (simulation results are consistent with observed results in 76.36% of the counties, and the deviation of an estimated aggregate loss value from its actual value is less than 2.79%) show that this model can more effectively represent the real world, and that the outputs, possible loss caused by multiple hazards, obtained with the model are reliable. The outputs can additionally help to identify which area is at greatest risk (of loss), and allow a determination of the reasons that contribute to the greatest losses. Hence, it is a useful tool which can provide further information for planners and decision-makers concerned with risk mitigation.
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Ahmadalipour, Ali. "Multi-Dimensional Drought Risk Assessment Based on Socio-Economic Vulnerabilities and Hydro-Climatological Factors." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/4038.
Full textAbstract:
Drought is among the costliest natural hazards developing slowly and affecting large areas, which imposes severe consequences on society and economy. Anthropogenic climate change is expected to exacerbate drought in various regions of the globe, making its associated socioeconomic impacts more severe. Such impacts are of higher concern in Africa, which is mainly characterized by arid climate and lacking infrastructure as well as social development. Furthermore, the continent is expected to experience vast population growth, which will make it more vulnerable to the adverse effects of drought. This study provides the first comprehensive multi-dimensional assessment of drought risk across the African continent as a function of hazard, vulnerability, and exposure. A multi-model and multi-scenario approach is employed to quantify drought hazard using the most recent ensemble of regional climate models and a multi-scalar drought index. Moreover, a rigorous framework is proposed and applied to assess drought vulnerability based on various sectors of economy, energy and infrastructure, health, land use, society, and water resources. Drought risk is then projected for different population scenarios and the changes of drought risk and the role of each component are investigated. In addition, the impacts of climate change on heat-stress mortality risk is assessed across the Middle East and North Africa. The results indicate vast increase for the projected drought risk with varied spatiotemporal patterns. Population growth and climate change will significantly escalate drought risk, especially in distant future. Therefore, climate change mitigation and adaptation planning as well as social development strategies should be carried out immediately in order to reduce the projected adverse risks on human life and society.
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Vaughan, David P. "Exploration of force transitions in stability operations using multi-agent simulation." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FVaughan.pdf.
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Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2006.<br>Thesis Advisor(s): Thomas W. Lucas, Edward J. Lesnowicz. "September 2006." Includes bibliographical references (p. 141-143). Also available in print.
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MILANI, RICCARDO. "MULTI-LEVEL CORRUPTION RISK INDICATORS IN THE ITALIAN PUBLIC PROCUREMENT." Doctoral thesis, Università Cattolica del Sacro Cuore, 2019. http://hdl.handle.net/10280/57129.
Full textAbstract:
Questo studio sviluppa un originale indicatore di rischio corruzione negli appalti pubblici Italiani e stima la correlazione tra le caratteristiche delle aziende aggiudicatarie e l’indicatore di rischio corruzione precedentemente stimato. L’indicatore di rischio corruzione è costruito a partire dai residui statistici di una procedura semi-parametrica a due stadi. Nella prima fase, i contratti dei lavori pubblici sono comparati per identificare l’inefficienza relativa di ciascun lavoro pubblico sulla base di due variabili predefinite – costi aggiuntivi e ritardi nella fase di esecuzione del contratto – attraverso una tecnica di valutazione delle performance (DEA). Nella seconda fase, l’indicatore di inefficienza generato nella prima fase è spiegato attraverso l’uso di determinanti di inefficienza, escludendo il fattore della corruzione che è trattato separatamente. Nella terza fase, i residui di stima sono trasformati in nuovi punteggi di rischio corruzione a livello di contratto pubblico. I risultati suggeriscono che: (1) le stazioni appaltanti ad elevato rischio corruzione si trovano maggiormente nel Lazio, in Lombardia e in Toscana; (2) le aziende aggiudicatarie ad alto rischio corruzione risiedono maggiormente nel Centro Italia (Abruzzo, Umbria e Lazio) e nel Sud Italia (Campania e Basilicata). Successivamente, l’esercizio di valutazione del rischio corruzione è mirato all'identificazione delle caratteristiche aziendali associate ad un rischio elevato di corruzione. I risultati suggeriscono che le aziende che si aggiudicano contratti ad alto rischio di corruzione sono più orientati alla ricerca del profitto, detengono meno debiti e necessitano mediamente di maggior tempo per pagare i loro clienti. Infine, queste aziende hanno maggiori probabilità di avere legami legali e/o finanziari con giurisdizioni off-shore e paradisi fiscali.<br>This study develops an original corruption risk indicator at the Italian procurement level and estimates the correlation between the profile of contract suppliers and the corruption risk indicator in question. This corruption risk indicator relies on a residual approach following a two-stage, semi-parametric procedure. First, public work contracts are benchmarked to investigate the relative efficiency of each public work execution based on two predefined variables – cost overrun and time delay – using a data envelopment analysis (DEA). Second, DEA efficiency scores are regressed on environmental and contract-level determinants of inefficiency – excluding corruption which is treated separately. Third, the estimate residuals provide estimates of the potential risk of corruption at the contract level. The aggregated results from an updated Italian public procurement dataset suggest that: (1) the risk of corruption associated with contracting authorities prevails in larger urban areas, especially in Lazio, Tuscany and Lombardy; (2) the risk of corruption in relation to the location of firms is higher in central regions (Abruzzo, Umbria and Lazio) and southern regions (Campania and Basilicata). Then, a risk-based assessment exercise is performed to profile suppliers. The corruption risk indicator is regressed on suppliers’ financial and ownership data to identify patterns among firms winning risky contracts. Suppliers associated with high levels of corruption risk in public contracting are more profit-seeking, hold low levels of debts and on average need more days to pay their customers. Finally, suppliers involved in public work contracts at high risk of corruption are more likely to have legal and/or financial connections with off-shore jurisdictions and tax havens which might use financial and corporate secrecy to attract illicit financial flows.
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MILANI, RICCARDO. "MULTI-LEVEL CORRUPTION RISK INDICATORS IN THE ITALIAN PUBLIC PROCUREMENT." Doctoral thesis, Università Cattolica del Sacro Cuore, 2019. http://hdl.handle.net/10280/57129.
Full textAbstract:
Questo studio sviluppa un originale indicatore di rischio corruzione negli appalti pubblici Italiani e stima la correlazione tra le caratteristiche delle aziende aggiudicatarie e l’indicatore di rischio corruzione precedentemente stimato. L’indicatore di rischio corruzione è costruito a partire dai residui statistici di una procedura semi-parametrica a due stadi. Nella prima fase, i contratti dei lavori pubblici sono comparati per identificare l’inefficienza relativa di ciascun lavoro pubblico sulla base di due variabili predefinite – costi aggiuntivi e ritardi nella fase di esecuzione del contratto – attraverso una tecnica di valutazione delle performance (DEA). Nella seconda fase, l’indicatore di inefficienza generato nella prima fase è spiegato attraverso l’uso di determinanti di inefficienza, escludendo il fattore della corruzione che è trattato separatamente. Nella terza fase, i residui di stima sono trasformati in nuovi punteggi di rischio corruzione a livello di contratto pubblico. I risultati suggeriscono che: (1) le stazioni appaltanti ad elevato rischio corruzione si trovano maggiormente nel Lazio, in Lombardia e in Toscana; (2) le aziende aggiudicatarie ad alto rischio corruzione risiedono maggiormente nel Centro Italia (Abruzzo, Umbria e Lazio) e nel Sud Italia (Campania e Basilicata). Successivamente, l’esercizio di valutazione del rischio corruzione è mirato all'identificazione delle caratteristiche aziendali associate ad un rischio elevato di corruzione. I risultati suggeriscono che le aziende che si aggiudicano contratti ad alto rischio di corruzione sono più orientati alla ricerca del profitto, detengono meno debiti e necessitano mediamente di maggior tempo per pagare i loro clienti. Infine, queste aziende hanno maggiori probabilità di avere legami legali e/o finanziari con giurisdizioni off-shore e paradisi fiscali.<br>This study develops an original corruption risk indicator at the Italian procurement level and estimates the correlation between the profile of contract suppliers and the corruption risk indicator in question. This corruption risk indicator relies on a residual approach following a two-stage, semi-parametric procedure. First, public work contracts are benchmarked to investigate the relative efficiency of each public work execution based on two predefined variables – cost overrun and time delay – using a data envelopment analysis (DEA). Second, DEA efficiency scores are regressed on environmental and contract-level determinants of inefficiency – excluding corruption which is treated separately. Third, the estimate residuals provide estimates of the potential risk of corruption at the contract level. The aggregated results from an updated Italian public procurement dataset suggest that: (1) the risk of corruption associated with contracting authorities prevails in larger urban areas, especially in Lazio, Tuscany and Lombardy; (2) the risk of corruption in relation to the location of firms is higher in central regions (Abruzzo, Umbria and Lazio) and southern regions (Campania and Basilicata). Then, a risk-based assessment exercise is performed to profile suppliers. The corruption risk indicator is regressed on suppliers’ financial and ownership data to identify patterns among firms winning risky contracts. Suppliers associated with high levels of corruption risk in public contracting are more profit-seeking, hold low levels of debts and on average need more days to pay their customers. Finally, suppliers involved in public work contracts at high risk of corruption are more likely to have legal and/or financial connections with off-shore jurisdictions and tax havens which might use financial and corporate secrecy to attract illicit financial flows.
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Sala-Diakanda, Serge. "A FRAMEWORK FOR THE ASSESSMENT AND ANALYSIS OF MULTI-HAZARDSINDUCED RISK RESULTING FROM SPACE VEHICLES OPERATIONS." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2337.
Full textAbstract:
With the foreseeable increase in traffic frequency to and from orbit, the safe operation of current and future space vehicles at designated spaceports has become a serious concern. Due to their high explosive energy potential, operating those launch vehicles presents a real risk to: (1) the spaceport infrastructure and personnel, (2) the communities surrounding the spaceport and (3) the flying aircrafts whose routes could be relatively close to spaceport launch and reentry routes. Several computer models aimed at modeling the effects of the different hazards generated by the breakup of such vehicles (e.g., fragmentation of debris, release of toxic gases, propagation of blast waves, etc.) have been developed, and are used to assist in Go-No Go launch decisions. They can simulate a total failure scenario of the vehicle and, estimate a number of casualties to be expected as a result of such failure. However, as all of these models – which can be very elaborate and complex – consider only one specific explosion hazard in their simulations, the decision of whether or not a launch should occur is currently based on the evaluation of several estimates of an expected number of casualties. As such, current practices ignore the complex, nonlinear interactions between the different hazards as well as the interdependencies between the estimates. In this study, we developed a new framework which makes use of information fusion theory, hazards' dispersion modeling and, geographical statistical analysis and visualization capabilities of geographical information systems to assess the risk generated by the operation of space launch vehicles. A new risk metric, which effectively addresses the lack of a common risk metric with current methods, is also proposed. A case study, based on a proposed spaceport in the state of Oklahoma showed that the estimates we generate through our framework consistently outperform estimates provided by any individual hazard, or by the independent combination of those hazards. Furthermore, the study revealed that using anything else than fusion could provide seriously misleading results, with potentially catastrophic consequences.<br>Ph.D.<br>Department of Industrial Engineering and Management Systems<br>Engineering and Computer Science<br>Industrial Engineering PhD
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Garratt-Reed, David. "An exploration of the cognitive mechanism underlying general risk-aversion in obsessive-compulsive disorder : the construction and validation of the multi-dimensional risk-assessment scale." Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/1850.
Full textAbstract:
Individuals with OCD avoid minor risks that are unrelated to their obsessive fears and this general risk-aversion is implicated in treatment failure and relapse. However, a lack of understanding of the cognitive biases driving general risk-aversion has hampered therapeutic efforts to address this problematic cognitive-behavioural pattern. This research was designed to advance understanding of these cognitive biases in order to potentially improve treatment outcomes for individuals with OCD.Perception of threat is a significant causal factor in risk-aversion and this research was designed to investigate the cognitive biases driving threat overestimation, and consequent risk-aversion, in general situations among individuals with OCD. Beck, Emery, and Greenberg’s (1985) model of threat perception formed the theoretical basis for this investigation. This model states that threat perception and consequent anxiety within a situation are the result of cognitive computations involving the perceived probability and perceived cost of potential negative events, along with perceived ability to cope with those events. However, no validated scales existed to measures these constructs, so the first undertaking in this research was to create the Multi-Dimensional Risk Assessment Scale (MDRAS) to perform this important task.The aim of Study 1 was the development of the MDRAS, a scale designed to assess perceptions of the probability and cost of specific negative events, as well as perceived ability to cope with those events. The events selected were unrelated to typical OCD concerns and include some everyday risks as well as some risks that are situated in the future. Items were generated based on items from two existing scales, the Everyday Risk Inventory-Australian Revision (ERI-AUS, Cicolini & Rees, 2003) and the Social Readjustment Rating Scale (SRRS, Holmes & Rahe, 1967). Two hundred and twenty two non-clinical participants, consisting of students at Curtin University and community members recruited through snowball sampling, completed the 19-item MDRAS. Principal components analyses (PCA) revealed that the MDRAS conformed to its intended factor structure, with the Probability, Cost, and Coping scales containing two factors relating to everyday risks and future risks. However, several items did not load as planned and were removed from the scale.A second PCA demonstrated that the shortened, 14-item version of the MDRAS contained 7 items assessing threat perceptions for everyday risks, and 7 items assessing threat perceptions for potential future risks. Confirmatory factor analysis (CFA) indicated that, in addition to two subordinate factors, Total Probability, Total Cost, and Total Coping scores could also be interpreted. As intended, the MDRAS appears to assess perceived probability and cost of potential negative daily and future events, and perceived ability to cope with those events.In Study 2 the pattern of relationships between the MDRAS scales and a measure of negative affect, a measure of obsessive beliefs, and a measure of perceived control was examined. Participants were the same individuals who had participated in Study 1. They completed the Positive and Negative Affect Schedule (PANAS; Watson, Clark, & Tellegen, 1988), the Obsessive Beliefs Questionnaire (OBQ; OCCWG, 2005), and the Anxiety Control Questionnaire (ACQ; Rapee, Craske, Brown, & Barlow, 1996) in addition to the MDRAS. Results provided evidence for the internal consistency as well as the convergent and discriminant validity of the MDRAS scales. It was concluded that the MDRAS appears to be a reliable and valid measure of perceptions of the probability and cost of negative events, and of perceived ability to cope with those events.In Study 3 MDRAS scores were compared among 21 individuals with OCD, 17 anxious controls, and 29 non-anxious controls. Participants completed the MDRAS and the PANAS in addition to a measure of obsessive symptoms – the Obsessive-Compulsive Inventory-Revised (OCI-R; Foa et al., 2002). Analyses of variance (ANOVAs) indicated that individuals with OCD perceived a higher cost of negative events and perceived their ability to cope with those events as lower than did non-clinical individuals. This was true for both the MDRAS Total Cost and Coping scales, as well as for the Everyday and Future Cost and Coping Scales, with medium to large effect sizes in each case. However, individuals with OCD did not estimate a higher probability of the occurrence of everyday or future negative events than did non-clinical individuals. This indicates that general risk-aversion among individuals with OCD is driven by inflated cost and reduced coping ability estimates. However, ANCOVAs revealed that, after controlling for negative affect, there were no differences between the OCD and the non-anxious groups on any of the MDRAS scales.This suggests that negative affect, rather than OCD specifically, is related to cost and coping ability biases, and consequent risk-aversion. In addition, ANOVAs revealed that the OCD group did not score differently from the anxious controls on any MDRAS scale, suggesting that all anxious individuals are likely to perceive heightened levels of cost associated with general negative events, and demonstrate low subjective ability to cope with those events. This is consistent with theories suggesting that general risk-aversion is a transdiagnostic risk factor for anxiety in general, rather than any specific diagnosis (Maner & Schmidt, 2006). It was concluded that individuals with OCD are risk-aversive because they overestimate the cost of potential negative events, and underestimate their ability to cope with those events. However, a similar conclusion was drawn for other anxious individuals and there was no evidence that general risk-aversion is a phenomenon specific to OCD.It was concluded that general risk-aversion is likely to be an important target for treatment across anxiety disorders and it would seem prudent to target biased estimates of the cost of negative events, and/or perceived ability to cope with those events, in order to reduce threat perception and general risk-aversion among anxious individuals. Methods for achieving this were discussed. In addition, it was concluded that the MDRAS has the potential to be a useful research and clinical tool for assessing the cognitive biases involved in threat overestimation and consequent risk-aversion among anxious individuals.
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Brookes, Victoria Jane. "A stakeholder-driven framework for exotic disease prioritisation and investigation, in the context of the domestic pig industry in Australia." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/11936.
Full textAbstract:
The objective of this project was to develop and implement a framework for prioritisation and investigation of biosecurity and contingency planning requirements for exotic diseases, in the context of the domestic pig industry in Australia. Multi-criteria decision analysis was used to prioritise diseases exotic to the pig industry in Australia. Probabilistic inversion and regression methods quantified the value of disease to stakeholders. Results demonstrated diverse preferences between stakeholders, regarding the importance of livestock impacts of diseases or zoonotic impacts of diseases. Industry stakeholders used the prioritisation lists as a decision-aid, and selected highly pathogenic porcine reproductive and respiratory syndrome (PRRS) for further disease investigation. Disease investigation assessed the risk of entry into Australia of highly pathogenic PRRS and the exposure of a pig to the virus. Industry stakeholders identified routes involving raw pork as having the highest risk of occurrence. Quantitative risk assessment demonstrated a greater probability of infection of a feral pig through ingestion of raw pork discarded on a property, than infection of a domestic pig through swill-fed raw pork. Sensitivity analysis and extension of scenarios using a viral-decay and dose-response model indicated research requirements into the probability of access by feral pigs to food-waste on rural properties, and demonstrated the importance of border biosecurity in regulating the disposal of food-waste from international traffic. This project demonstrated that stakeholder opinion and knowledge can be used in a transparent and reproducible manner as a decision-aid to direct resources for industry biosecurity and contingency planning. This framework is applicable for use by other agricultural industries and in public health, and as a science-based method to incorporate stakeholder opinion and knowledge into government biosecurity policy.
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Splajt, Tanya D. "Application of multi-scale assessment and modelling of landfill leachate migration : implications for risk-based contaminated land assessment, landfill remediation, and groundwater protection." Thesis, University of Hull, 2004. http://hydra.hull.ac.uk/resources/hull:5600.
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There are a large number of unlined and historical landfill sites across Britain, contaminating groundwater and soil resources as well as posing a threat to human health and local communities. There is an essential requirement for robust methodology when carrying out risk-based site investigations prior to risk assessment and remediation of landfill sites. This research has focused upon the methods used during site investigations for two reasons. Firstly, the site investigation is often conducted using field instruments and methods that do not account for the heterogeneous conditions found at landfill sites. Interpreting geophysical conditions between sampled points is a common practise. Given the complex and heterogeneous conditions at landfill sites, such methodology introduces uncertainty into data sets. Secondly, risk estimation models that simulate groundwater flow and contaminant transport require extensive field information. The data used during model construction will significantly impact contaminant transport simulations. Modelling guidelines also need further development, ensuring that sound modelling practises are adhered to during model construction. To address these concerns, four research objectives were identified: (1) Two new multi-spatial field assessment methods (remote sensing and ground penetrating radar), previously applied in other fields of science, were tested on landfill sites; (2) Kriging was used as a tool to improve landfill-sampling strategies; (3 & 4) Groundwater flow and contaminant transport models were used to evaluate whether different scales of field data and modelling practises influenced modelling assumptions and simulation. The utility of novel field- and airborne-based remote sensing methodologies in identifying the location and intensity of vegetation stress caused by leachate migration and inferring pathways of near surface contamination using patterns of vegetation stress was proven. The results from the kriging investigations demonstrated that additional insight into field conditions could be resolved to identify locations of additional sampling points, and provide information about variability in hydrological data sets. The Ground Penetrating Radar investigations provided three types of valuable near-surface information that could assist in determining landfill risks: buried landfill features, leachate plume locations and local hydrogeological conditions. These combined methods provided detailed synoptic geophysical and contaminant information that would otherwise be difficult to determine. Their application and acceptance as site assessment methods (used under certain landfill conditions) could increase the accuracy of assessing risks posed by landfill leachate. These applications also demonstrated that the most effective site assessments are achieved when integrated with other field data such as soil, vegetation, and groundwater quantity measurements, contaminant concentrations and aerial photographs, providing comprehensive information needed for risk estimation modelling. The modelling analyses found that close attention must be paid to site-specific and model-specific characteristics, as well as modelling practises. These factors influenced model results. By using additional data to infer model parameters, it was evident that the amount of data available will influence the way in which risk will be perceived. The more data that was available during model construction, the higher the risk prediction. This was the case for some seventy- percent of the models. By improving the accuracy of site investigation methodology, and by adhering to robust assessment and modelling practices, a higher level of quality assurance can be achieved in the risk assessment and remediation of contaminating landfill sites. If the improvements and recommendations presented in this research are considered, uncertainties inherent in the site investigation could be reduced, therefore enhancing the accuracy of landfill risk assessment and remedial decisions.
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Hassan, Waqar Ul. "Pixel Based and Object Oriented Multi-spectral Remotely Sensed Data Analysis for Flood Risk Assessment and Vulnerability Mapping." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-64011.
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Geographical information system with remotely sensed data can be instrumental in many ways for disaster management and post disaster rehabilitation. During last few decades the usage of remotely sensed data has extensively increased, although image interpretation tools are not highly accurate but still considered as fast, reliable and useful way to get information from imagery. Disaster assessment, management and rehabilitation are always creates challenge for experts. Population growth, expansion in settlements either in the rural or in the urban areas bring more problems not only for the humans but it also affect the global environment Such global changes on the massive scale disturbs the ecological processes. GIS along with Remote sensing data can change the whole scenario in very short period of time. All the departments concerning to strategic disaster planning process can share their information by using the single platform, so for this purpose spatial database can be helpful by providing the spatial data in digital format to the department concerned. Spatial phenomena can be observed by using different image analysis techniques and the resultant thematic map display the spatial variations and changes that describe the particular phenomenon whether it was any disaster or change in soil type or vegetation type. Remotely sensed data like aerial, satellite and radar images are very useful for disaster management strategy formulation process. Integration of GIS and remote sensing proved itself the best especially for land-use, land-cover mapping. For this purpose pixel based, sub-pixel based, pre-field and object oriented classification approach are being in use around the world. But thematic maps created from image analyzed by using object oriented classifiers contain more accuracy than any other techniques.
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Ordaz, Irian. "A probabilistic and multi-objective conceptual design methodology for the evaluation of thermal management systems on air-breathing hypersonic vehicles." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26478.
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Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009.<br>Committee Chair: Mavris, Dimitri N.; Committee Member: German, Brian J.; Committee Member: Osburg, Jan; Committee Member: Ruffin, Stephen M.; Committee Member: Schrage, Daniel P.. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Wu, Ting-Yeh. "Vulnerability Assessment of Land Use Regulation by Multi-Criteria Decision Analysis for a Sediment Hazard Prone Catchment." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120852.
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Rodrigo, Ana Patrícia Carreira. "Integration of sediment contamination with multi–biomarker responses in a novel bioindicator candidate (Sepia officinalis) for risk assessment in impacted estuaries." Master's thesis, Faculdade de Ciências e Tecnologia, 2012. http://hdl.handle.net/10362/8080.
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Dissertação para obtenção do Grau de Mestre em
Engenharia do Ambiente<br>The Sado estuary (SW Portugal) is an example of the type of pressures coastal areas are subjected to, encompassing fisheries, agriculture, industries and other human activities, most of which may act as sources of aquatic pollution. In order to assess the impact of aquatic contaminants onto the biota, biomonitoring is compelling and the search for suitable bioindicator organisms is mandatory. The common cuttlefish, Sepia officinalis, is a very important species to fisheries, especially in the Sado estuary, albeit yet unsurveyed in ecotoxicological studies. For the purposes of biomonitoring, cuttlefish were collected from two different sites in the Sado estuary and from an external reference area. Additionally, environmental contamination was determined from sediment samples. Sediments were characterized for granulometric fractions, total organic matter, redox potential and for the levels of metals (Cr, Ni, Cu, Zn, Cd and Pb), metalloids (As and Se), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and the pesticides dichloro diphenyl trichloethane plus its main metabolites (DDTs) and hexoclorobenzene (HCB). A multi–biomarker approach was applied in two organs, digestive gland and gills, through the analysis of lipid peroxidation, total glutathione, the reduced/oxidised glutathione ratio, glutathione S–transferase activity and induction of metallothionein–like proteins. The results showed that the Sado estuary is especially contaminated by metals when compared to the reference area. In addition, even within the Sado estuary, considerable heterogeneity exists regarding sediment contamination. The biomarker responses, especially in the digestive gland, were overall consistent with sediment contamination. This relationship was less obvious in the gills, reflecting, nevertheless, high sensibility to environmental pressures. Thus, S. officinalis revealed to be a good species to address environmental contamination and likely an adequate bioindicator in environmental risk assessment programs. The integration of all biomarker responses disclosed that the levels of contamination of the Sado estuary, although considered to be moderate, cause responses and adverse effects in organisms, from which it may be inferred that current management policies have not yet been able to eradicate pollution from this ecosystem.
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Gallina, Valentina <1985>. "An advanced methodology for the multi-risk assessment : an application for climate change impacts in the North Adriatic case study (Italy)." Doctoral thesis, Università Ca' Foscari Venezia, 2014. http://hdl.handle.net/10579/5613.
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Climate change will pose multiple impacts on natural and human systems worldwide, increasing risks from long-term climate trends and disasters triggered by weather extremes. Till now, a hazard by hazard approach was considered in risk assessment for evaluating the consequences of individual natural and climate-related hazards (e.g. heavy precipitation events, droughts, floods, debris flows, landslides, storm surges) on vulnerable systems, without any consideration of an integrated assessment of multiple risks triggered by different forces.
Starting from an initial review of existing multi-risk assessment concepts and tools applied by international organisations and projects, the main aim of the thesis was to develop and apply an advanced and interdisciplinary multi-risk methodology, allowing a sound assessment and communication of the multi-faceted threats posed by a variety of climate-related hazards across regions and sectors. A multi-hazard assessment was developed to analyze the relationships of multiple hazards (e.g. sea-level rise, coastal erosion, storm surge) happening in the same spatial and temporal area, using an influence matrix and the disjoint probability. Then, the multi-vulnerability of different exposed receptors (e.g. natural systems, beaches, agricultural and urban areas) was estimated trough a variety of vulnerability indicators (e.g. vegetation cover, sediment budget, % of urbanization) associated to different hazards. Finally, the multi-risk assessment was performed by integrating the multi-hazard with the multi-vulnerability index for the exposed receptors, thus supporting the development of information useful to stakeholders in the definition of adaptation strategies. The methodology was tested in the North Adriatic coast producing GIS-based multi-hazard, exposure, multi-vulnerability and multi-risk maps. The results of the analysis showed that the areas affected by higher multi-hazard scores are located close to the coastline where all the investigated hazards are present. Multi-vulnerability assumes relatively high scores in the whole case study, showing that beaches, wetlands, protected areas and river mouths are the more sensible targets. Finally, the multi-risk map presents a similar trend of the multi-hazard map, highlighting beaches as the receptor more affected by multi-risk with a relevant percentage of surface (i.e. 60%) in the very high and high multi-risk classes. The final estimate of multi-risk for coastal municipalities provides useful information for local public authorities to set future priorities for adaptation and define future plans for shoreline and coastal management in view of climate change.
In conclusion, the proposed multi-risk methodology is a step forward to traditional single risk assessments, providing a more comprehensive – even if relative - assessment of the multiple impacts and risks affecting the same area. Moreover, moving from the multi-risk methodologies generally developed for natural hazards, the presented methodology considers also future scenarios of climate-related hazards, providing a generic guideline for its application to different case studies, scale of analysis and contexts. The proposed multi-risk methodology can be applied adopting a bottom-up approach considering stakeholder needs in order to obtain tailored risk-based adaptation services suitable to mainstream adaptation in the development of plans, policies and programmes.
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Ferreira, Nuno Gonçalo de Carvalho. "The effects of chemicals in isopods: a multi-organizational evaluation." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14095.
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Doutoramento em Biologia<br>The global aim of this thesis was to evaluate and assess the effects of a
pesticide (dimethoate) and a metal (nickel), as model chemicals, within different
organization levels, starting at the detoxification pathways (enzymatic
biomarkers) and energy costs associated (energy content quantification,
energy consumption and CEA) along with the physiological alterations at the
individual and population level (mortality), leading to a metabolomic analysis
(using liquid 1H-NMR) and finally a gene expression analysis (transcriptome
and RT-qPCR analysis). To better understand potential variations in response
to stressors, abiotic factors were also assessed in terrestrial isopods such as
temperature, soil moisture and UV radiation.
The evaluation performed using biochemical biomarkers and energy related
parameters showed that increases in temperature might negatively affect the
organisms by generating oxidative stress. It also showed that this species is
acclimated to environments with low soil moisture, and that in high moisture
scenarios there was a short gap between the optimal and adverse conditions
that led to increased mortality. As for UV-R, doses nowadays present have
shown to induce significant negative impact on these organisms.
The long-term exposure to dimethoate showed that besides the neurotoxicity
resulting from acetylcholinesterase inhibition, this stressor also caused
oxidative stress. This effect was observed for both concentrations used
(recommended field dose application and a below EC50 value) and that its
combination with different temperatures (20ºC and 25ºC) showed different
response patterns. It was also observed that dimethoate’s degradation rate in
soils was higher in the presence of isopods.
In a similar study performed with nickel, oxidative stress was also observed.
But, in the case of this stressor exposure, organisms showed a strategy where
the energetic costs necessary for detoxification (biomarkers) seemed to be
compensated by positive alterations in the energy related parameters.
In this work we presented for the first time a metabolomic profile of terrestrial
isopods exposed to stressors (dimethoate and niquel), since until the moment
only a previous study was performed on a metabolomic evaluation in nonexposed
isopods. In the first part of the study we identify 24 new metabolites
that had not been described previously. On the second part of the study a
metabolomic profile variation of
abstract non-exposed organism throughout the exposure was presented and
finally the metabolomic profile of organisms exposed to dimethoate
and nickel. The exposure to nickel suggested alteration in growth,
moult, haemocyanin and glutathione synthesis, energy pathways and
in osmoregulation. As for the exposure to dimethoate alterations in
osmoregulation, energy pathways, moult and neurotransmission were
also suggested.
In this work it was also presented the first full body transcriptome of a
terrestrial isopod from the species Porcellionides pruinosus, which will
complement the scarce information available for this group of
organisms. This transcriptome also served as base for a RNA-Seq and
a RT-qPCR analysis. The results of the RNA-Seq analysis performed
in organisms exposed to nickel showed that this stressor negatively
impacted at the genetic and epigenetic levels, in the trafficking,
storage and elimination of metals, generates oxidative stress, inducing
neurotoxicity and also affecting reproduction. These results were
confirmed through RT-qPCR. As for the impact of dimethoate on these
organisms it was only accessed through RT-qPCR and showed
oxidative stress, an impact in neurotransmission, in epigenetic
markers, DNA repair and cell cycle impairment.
This study allowed the design of an Adverse Outcome Pathway draft
that can be used further on for legislative purposes.<br>Os efeitos negativos de contaminantes de origem antropogénica que
aparecem no meio ambiente têm um impacto negativo muitas vezes em
organismos considerados benéficos. Dentro deste grupo de organismos
podemos incluir os isópodes terrestres, detritivorous, cuja função se baseia na
fragmentação de matéria vegetal, que poderão posteriormente ser facilmente
colonizados por bactérias e os seus nutrientes incorporados nos solos.
Para avaliar os efeitos de contaminantes em isópodes terrestres, mais
concretamente na espécie Porcellionides pruinosus, foram usados como
modelos o metal níquel e o pesticida dimetoato, fazendo uma abordagem em
diferentes níveis organizacionais. O trabalho iniciou-se pela avaliação do
impacto a nível das vias de destoxificação (biomarcadores enzimáticos) e
reservas energéticas (quantificação das reservas, consumo energético e
alocação da energia celular), juntamente com alterações a nível dos indivíduos
e da população (mortalidade), passando por uma análise de metabolómica
(usando 1H-RMN de líquidos) e finalmente uma análise da expressão génica
(transcriptoma e RT-qPCR). De forma a melhor entender as variações que
podem ocorrer oriundas de variações de fatores abióticos, foi também
realizado um estudo sob os efeitos da variação de temperatura, humidade do
solo e radiação UV em isópodes terrestres.
A avaliação feita a nível dos biomarcadores bioquímicos, quantificação das
reservas e parâmetros energéticos demonstrou que o aumento da temperatura
iria afectar negativamente os organismos devido ao stress oxidativo gerado.
Tendo em conta que esta espécie está aclimatada a ambientes com solos com
humidades baixas, a exposição a solos com humidades superiores mostrou a
existência de um pequeno intervalo entre o que são consideradas condições
óptimas e condições bastante adversas, sendo aí verifica uma elevada
mortalidade. Os efeitos da radiação UV demonstraram que as doses que
actualmente chegam à superfície do planeta constituem uma ameaça para os
isópodes terrestres.
A avaliação feita à toxicidade do dimetoato em biomarcadores bioquímicos,
reservas e parâmetros energéticos, demonstrou que além da toxicidade já
esperada (inibição da enzima acetilcolinesterase), este stressor induz
igualmente stress oxidativo. Este efeito foi observado para ambas as
concentrações usadas (dose recomendada de aplicação em campo e dose
próxima do EC50) e que a sua combinação com diferentes temperaturas (20ºC
resumo e 25ºC) dava origem a diferentes padrões de resposta. Também foi observado
que a taxa de degradação do dimetoato era superior em solos com a presença
de isópodes.
Num estudo semelhante ao anterior, realizado com níquel, foi observada
toxicidade induzida por stress oxidativo. No entanto os organismos expostos a
este stressor apresentam uma estratégia em que os custos energéticos
associados à destoxificação (biomarcadores bioquímicos) parecem ser
compensados com alterações positivas a nível dos parâmetros energéticos.
Neste trabalho é apresentado pela primeira vez o perfil metabolómico de
isópodes terrestres expostos a dimetoato e níquel, sendo que até à data
apenas um estudo tinha apresentado o perfil metabólico de isópodes em
situação de homeostasia. Na primeira parte do estudo é apresentado o perfil
metabólico que identifica 24 novos metabolitos que ainda não tinham sido
descritos anteriormente. Numa segunda parte é apresentada uma variação do
perfil de organismos não expostos ao longo do ensaio e finalmente são
apresentadas as variações metabólicas em organismos expostos a dimetoato
e a níquel. Os resultados mostraram que ambos os stressores causaram
alterações que eram dependentes da concentração e do tempo. Quando
expostos a níquel os organismos evidenciam alterações ao nível do
crescimento, muda e síntese de hemocianina e glutationas, alterações ao nível
das vias energéticas e na osmorregulação. Em relação aos efeitos da
exposição a dimetoato, foram observadas alterações a nível da
osmorregulação, das vias energéticas e na muda, mas também ao nível da
neurotransmissão.
Neste trabalho é apresentado pela primeira vez um transcriptoma completo de
um isópode terrestre, da espécie Porcellionides pruinosus. Este transcriptoma
veio complementar a atual, mas parca, informação disponível sobre este grupo
de organismos. Tendo como base o transcriptoma, foi posteriormente realizada
uma análise de RNA-Seq e de RT-qPCR. A análise de RNA-Seq foi realizada
apenas em organismos expostos a níquel e mostrou que este stressor tem um
impacto ao nível genético e epigenético, no transporte, acumulação e
eliminação de metais, gera stress oxidativo, neurotoxicidade e afecta também
a reprodução. Estes resultados foram confirmados pela análise feita através de
RT-qPCR. Em relação aos efeitos de dimetoato nestes organismos a nível
genómico, a sua avaliação foi apenas realizada através de RT-qPCR. Foi
observado que este stressor gera stress oxidativo, neurotoxicidade, tem um
impacto em marcadores epigenéticos, na reparação de ADN e provoca
alterações a nível da divisão celular.
Este estudo permitiu a realização de uma “Adverse Outcome Pathway” (AOP)
que poderá ser usada mais tarde para fins legislativos.
31
Mussen, Filip. "The evaluation of methods for benefit-risk assessment of medicines and the development of a new model using multi-criteria decision analysis." Thesis, Cardiff University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438761.
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MOLLAEEFAR, MAJID. "Automating the Quantification and Mitigation of Risks for Multiple Stakeholders." Doctoral thesis, Università degli studi di Genova, 2022. https://hdl.handle.net/11567/1101457.
Full textAbstract:
Cybersecurity risk management consists of several steps including the selection of appropriate controls to minimize risks. This is a difficult task that requires searching through all possible subsets of a set of available controls and identifying those that minimize the risks of all stakeholders. Since stakeholders may have different perceptions of the risks (especially when considering the impact of threats), conflicting goals may arise that require finding the best possible trade-offs among the various needs such as costs and expertise needed to deploy controls. The ability to tackle this kind of problem is particularly relevant when considering privacy provisions deriving from national or international regulations (such as the General Data Protection Regulation, GDPR) whereby the organization offering a data processing activity should reduce the user’s risk to an acceptable level while controlling costs and other business goals. In this context, being able to compute the subsets of controls that minimize the risks of both the organization of the system and its users is a necessary prerequisite to identify the most appropriate configuration of the controls that offer the best possible trade-off among the various objectives. The thesis proposes a quantitative and (semi)-automated approach to solve this problem based on the well-known notion of Pareto optimality. First, we describe a methodology to semi-automatically assist stakeholders in defining their objectives that measures how much risks are reduced by adopting a certain configuration of mitigation controls. Second, we define a decidable multi-objective optimization problem (based on the objectives previously identified)|called Multi-Stakeholder Risk Minimization Problem (MSRMP)|whose Pareto optimal solutions are the subsets of the controls for which no stakeholder’s risk can be further reduced without increasing the risk of at least one of the other stakeholders. Third, we validate our approach by showing how a prototype tool based on it can assist in the Data Protection Impact Assessment mandated by the General Data Protection Regulation on different use case scenarios. Lastly, we evaluate the scalability of the approach by conducting an experimental evaluation.
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Das, Jodie. "An investigation into how multi agency risk assessment conferences apply the principles for best practice when working interprofessionally with survivors of domestic violence and abuse and their families." Thesis, City University London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.549563.
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Mancini, Simona. "Development of an adaptive hierarchical multi-scale approach for the assessment, planning and prevention of the impact on anthropic and natural environments due to the exceeding of radon gas concentrations above threshold values and the corresponding risk associated to indoor radon exposures." Doctoral thesis, Universita degli studi di Salerno, 2018. http://hdl.handle.net/10556/3006.
Full textAbstract:
2016 - 2017<br>With its publication, the Directive not only acknowledges the latest international research results but reopens the scientific panorama of the control and monitoring of Radon concentrations, which had a period of stasis succeeding the completed accomplishment of the previous European Directive 96/29/Euratom.
In view of what will be the national accomplishments of the ED 59/2013/Euratom, scheduled within February 2018, in order to succeed next national strategies, the construction of an innovative approach based on an interdisciplinary methodology applicable on the European scale is necessary and urgent. The challenge posed by this task is a very demanding one as since 1990, the approach of developing national strategies has not been the same in the different European countries, leading to a broad range of different practices and regulations. Identifying the strong points among these ones and integrating the most recent scientific results in the field is a strategic way for the developing of a complete comprehensive approach as required by the new ED. After a deep bibliographic review to identify the most significant results, strength, weakness and critical issue of different approaches adopted in the scientific panorama, the author’s ambition is to propose a new adaptive general approach for the assessment, planning and prevention of the impact, on anthropic and natural environments, due to the exceeding of Radon gas concentrations from threshold values and the corresponding risk associated to indoor radon exposures. The methodology aims to be a first proposal in the scientific panorama accomplishing the most recent regulatory requirements... [edited by Author]<br>XXX ciclo
35
Payne, Ariane. "Rôle de la faune sauvage dans le système multi-hôtes de Mycobacterium bovis et risque de transmission entre faune sauvage et bovins : étude expérimentale en Côte d’Or." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10040/document.
Full textAbstract:
La tuberculose bovine causée par Mycobacterium bovis (M. bovis) est une zoonose multi-hôtes. Outre les bovins, elle peut être transmise à des populations sauvages variées dont certaines peuvent entretenir l'infection et/ou la retransmettre aux bovins, pouvant empêcher leur assainissement. Les conditions de persistance de M. bovis dans les populations sauvages ont été étudiées dans différentes régions du monde, mettant en lumière des statuts épidémiologiques variables selon les espèces et les contextes géographiques, cynégétiques et zootechniques. Notre objectif était de déterminer le rôle des différentes populations-hôtes sauvages impliquées dans le système multi-hôtes de M. bovis en Côte d'Or où, en plus des bovins, la tuberculose bovine, circule chez le blaireau, le sanglier, le cerf et le renard. Pour cela, nous avons estimé les niveaux d'infection et d'excrétion, les niveaux de densité, et au moyen d'un suivi télémétrique et de dispositif de vidéosurveillance, nous avons estimé les contacts entre les populations sauvages et les bovins. Nos résultats suggèrent que les trois populations ayant le rôle le plus important et aptes à retransmettre l'infection aux bovins sont le blaireau, le sanglier et le cerf, mais d'autres études sont encore nécessaires pour confirmer ces hypothèses et savoir si certaines d'entre elles peuvent entretenir l'infection de façon autonome. Elles pourraient, également, conjointement, constituer une communauté d'hôtes réservoir. Enfin, nos résultats nous ont permis de caractériser le risque de transmission de tuberculose bovine de ces populations sauvages vers les bovins et de proposer des mesures de lutte visant à réduire ce risque<br>Bovine tuberculosis, caused by Mycobacterium bovis is a multi-host zoonosis. Besides cattle,it can be transmitted to various wild populations and some of them are able to maintain or to spillback the infection to cattle, thus hampering control strategies. The maintenance of M. bovis by wild populations is dependent on species, on geographical configurations, and on hunting and husbandry practices. Our objective was to investigate the role the different wild populations involved in the M. bovis multi-host system of Côte d’Or, where bTB has been reoccuring in cattle since 2002 and has also been found in badgers, wild boar, red deer and foxes. To do so, we have assessed different risk factors. These include infection rate, ability to 10 shed M. bovis, populations densities and level of indirect contact between wild populations and cattle. For the latter factor, we have tracked 11 wild boars and 10 badgers and used remote surveillance in cattle farms. Our results suggest that, in the study site, badgers, wild boar and red deer may be able to spillback the infection to cattle. Nevertheless, further studies are required to confirm these hypotheses and to investigate whether some of these wild populations can act, individually as reservoirs. It might also be the case that, taken jointly, these wild populations could constitute a maintenance community. On the basis of our results, we made recommandations aiming at reducing the risk of spillback transmission
36
MUZI, STEFANIA. "Relationships among internalizing and externalizing problems, attachment and alexithymia in high-risk and community adolescents: a multi-method comparative study." Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1005727.
Full textAbstract:
Late-adopted (i.e. adopted after 12months) and residential-care adolescents, due to higher rates of adverse childhood experiences, show high rates of internalizing-externalizing problems and they are at high-risk to show attachment insecurity and alexithymia, which are risk-factors that may increase psychopathological vulnerability during adolescence.
However, no studies before compare in the same occasion these two high-risk groups of adolescents with community peers in internalizing-externalizing problems, attachment and alexithymia, which were never assessed simultaneously in these groups.
This mixed-method comparative research involved 174 non-clinical adolescents aged 10-19 years (M = 15.55, SD = 2.02, 53% boys) matched for age and gender in 3 groups: two "high-risk groups" of 33 late-adoptees (LA, i.e. adopted after 12 months) and 50 in residential-care (RC), and 91 community teens as low-risk control group (C), with two main aims: 1) to compare groups in internalizing-externalizing problems, attachment and alexithymia with a mixed-method, multi-informant approach, in order to check the assumed vulnerability of high-risk adolescents in these variables. 2) to explore relationships between internalizing-externalizing problems, attachment and alexithymia through groups, exploring the cumulative and interactive effects of attachment and alexithymia as possible risk factors for more internalizing-externalizing problems during adolescence.
After the approval of the University's Research Ethic Commitee, formal agreements with the Social and Health Services for adoption and residential-care and high-school for the recruitment of participants,and the signature by legal care-takers of an informed consent for the voluntarly participation of the adolescent in the research, each participant was assessed in two meetings in home visiting. Measures were: The Child Behavior Check List 6-18 years (CBCL, filled by a biological or adoptive parent and by the educator in the RC group) and the Youth Self Report 11-18 years (YSR) to assess internalizing-externalizing problems; the Friends and Family Interview (FFI) and the Inventory for Parent and Peer Attachment (IPPA) to assess attachment representations and relationships; the Toronto Alexithymia Scale 20 item (TAS-20) and the Toronto Structured Interview for Alexithymia (TSIA) to assess alexithymia; the verbal comprehension index of the Weschler Intelligence Scale for Children 4th edition (ICV-WISC-IV) to control the confounding effect of participant's verbal skills in the interview, plus a socio-demographic data form to collect demographic and anamnestic data (e.g. age and lenght of adoption or institituionalization, reasons).
Main results were: 1) Residential-care adolescents were confirmed the group more vulnerable to internalizing-externalizing problems, attachment insecurity and higher alexithymia, while late-adopted and community adolescents did not show differences each other. 2) Attachment insecurity and higher alexithymia were related to total and internalizing problems in all groups, while no relations with externalizing problems were found. 3) Alexithymia was a common risk-factors for more total and internalizing problems through groups, while attachment patterns had different group-specific roles. Overall, models of prediction inclusive of attachment and alexithymia allowed the prediction of 4%-39% of total problems and 20%-66% of internalizing problems through groups, with higher vulnerability for girls and a certain variability related to the problem's informant (care-giver or adolescent). In the discussion, shared and specific vulnerabilities of each group from a clinical point of view were discussed, commenting on the practical implications and suggesting ways of using these risk prediction models in clinical practice. In the conclusion, the utility of a mixed-method multi-informant approach was highlighted.
37
Nygren, Peggy. "Exploring the Effects of Multi-Level Protective and Risk Factors on Child and Parenting Outcomes in Families Participating in Healthy Start/Healthy Families Oregon (HS/HFO)." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1513.
Full textAbstract:
While many studies focus on the links between multiple risk factors and negative outcomes such as child maltreatment, less is known about the influence of protective factors in the face of risks. The theoretical base of this study was a social ecological model of interactive influences including individual parent, family, and neighborhood level factors to predict outcomes. Protective Factor Index (PFI) and Risk Factor Index (RFI) predictors were developed to explore potential multi-level protective factor buffering effects on key child development and parenting outcomes. Participants were first time mothers enrolled in a randomized controlled study of the Healthy Start/ Healthy Families Oregon (HS/HFO) home visitation program (treatment group) who completed a follow-up phone survey at the child’s 12 month birthday (n = 405). Families were offered HS/HFO services prenatally after meeting risk screening eligibility criteria on the New Baby Questionnaire (NBQ). Program mothers having received at least one home visit (n = 248) were included in the final analyses. Families had an average of 3.1 (SD = 1.2) NBQ risk factors at enrollment and 83% reported having trouble paying for basic needs. Families received an average of 16 home visits in the first 6 months of the program. Thirty-one percent of mothers were aged 19 or younger, 60% were White and Non-Hispanic, 31% were Hispanic, and 9% were another race/ethnicity. Hierarchical regression models with main effects (RFI, PFI, race) and an interaction term (RFI X PFI) were developed to predict eight outcomes. Interaction effects models were not significant. Five RFI main effects were significant: higher RFI scores were associated with greater likelihood of child welfare involvement, greater parenting stress, less favorable scores on child health and well-being, lower parent responsiveness and ii acceptance, and less supportive learning environments. One PFI main effect was significant: higher PFI scores predicted lower parenting stress. A trend level result showed higher PFI scores were associated with less child welfare involvement. Race was significant in two models: White/Non-Hispanic families were more likely to have a home visitor report child welfare involvement and had more frequent parent-child activities compared to other race/ethnicity families. Unpacking the results with separate single risk factor (12 items) and protective factor (10 items) regression models followed. Results showed parent’s prior family history of maltreatment and younger maternal age predicted child welfare involvement (home visitor report), while protection was seen for those with access to housing support. Social support and family functioning protectors were linked to lower parenting stress, while maternal depression showed the opposite finding. Better scores on a child health and well-being measure were seen with higher neighborhood cohesion and greater participation in HS/HFO; in contrast, neighborhood violence and frequent mobility were linked to worse scores. Developmentally supportive home environments were seen for families participating in additional parent support programs, in which the mother had greater knowledge of infant milestones and behavior, and if the family had access to housing supports. Unemployment proved to be associated with less enriched home environments. In summary, there was no support for the cumulative PFI in buffering risk for negative outcomes in this model. The RFI was also a more robust predictor of outcomes compared to the PFI in the main effects models. Overall, study findings provide some evidence for the utility of specific protective factors, as well as cumulative and specific single risk factors, for screening families for effectively targeting services and guiding the conceptual development of program and evaluation formats.
38
Staedelin, Marie. "Methodological approaches for the benefit-risk assessment of medicinal products in European regulatory decision-making : a special emphasis on the MultiCriteria Decision Analysis "MCDA” Method a quantitative approach." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAJ013.
Full textAbstract:
L'évaluation des bénéfices et des risques des médicaments joue un rôle central dans la protection de la santé publique. Cependant, et de l’avis général, il apparaît que cette évaluation nécessite d’être revisitée. En 2010, aucun examen n’avait encore été effectué pour déterminer si les méthodes disponibles pouvaient être appliquées à l’évaluation de la balance bénéfice-risque des médicaments dans le cadre réglementaire, et si oui à quel point elles seraient applicable. L’objectif de cette thèse a donc été d’identifier la ou les méthodes pouvant être théoriquement utilisées pour ce type d’évaluation, puis de les confronter à des cas concrets afin d’en déterminer leur applicabilité. Les résultats de l’évaluation des méthodes ont montrés que les méthodes les plus appropriées sont la méthode d’aide à la décision multicritère (MCDA) ainsi que ses variantes. Les résultats de l'application pratique de la méthode MCDA ont indiqué que cette méthode peut être utilisé dans les scénarios communs d'enregistrement en Europe. Cependant il convient de noter que cette méthode ne fournit ni une recette « prête à l'emploi » pour exécuter cette évaluation ni une réponse directe<br>The benefit-risk evaluation of new medicines plays a central role in safeguarding public health. Nevertheless, it seems that the benefit-risk evaluation calls for further improvement. In 2010, no review had been performed of how available benefit-risk assessment methods could be applied for a regulatory benefit-risk assessment and how feasible that would be when facing real-life cases. The objective of this thesis has thus been to identify method(s) that could be theoretically used for such an assessment, and then to confront it/them to real-life cases, in order to determine their applicability. The results of the methods evaluation showed that the most suitable methods for a regulatory benefit-risk assessment of medicinal products are the MCDA method and the MCDA based methods. The results of the practical application of the MCDA indicated that the method could be used for medicinal products registered through a common registration scenario in Europe. However it should be noted that this method provides neither a “ready-made” recipe to perform an assessment nor a direct answer
39
Ranjeet, Tirtha. "Coevolutionary algorithms for the optimization of strategies for red teaming applications." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2012. https://ro.ecu.edu.au/theses/558.
Full textAbstract:
Red teaming (RT) is a process that assists an organization in finding vulnerabilities in a system whereby the organization itself takes on the role of an “attacker” to test the system. It is used in various domains including military operations. Traditionally, it is a manual process with some obvious weaknesses: it is expensive, time-consuming, and limited from the perspective of humans “thinking inside the box”. Automated RT is an approach that has the potential to overcome these weaknesses. In this approach both the red team (enemy forces) and blue team (friendly forces) are modelled as intelligent agents in a multi-agent system and the idea is to run many computer simulations, pitting the plan of the red team against the plan of blue team.
This research project investigated techniques that can support automated red teaming by conducting a systematic study involving a genetic algorithm (GA), a basic coevolutionary algorithm and three variants of the coevolutionary algorithm. An initial pilot study involving the GA showed some limitations, as GAs only support the optimization of a single population at a time against a fixed strategy. However, in red teaming it is not sufficient to consider just one, or even a few, opponent‟s strategies as, in reality, each team needs to adjust their strategy to account for different strategies that competing teams may utilize at different points. Coevolutionary algorithms (CEAs) were identified as suitable algorithms which were capable of optimizing two teams simultaneously for red teaming. The subsequent investigation of CEAs examined their performance in addressing the characteristics of red teaming problems, such as intransitivity relationships and multimodality, before employing them to optimize two red teaming scenarios. A number of measures were used to evaluate the performance of CEAs and in terms of multimodality, this study introduced a novel n-peak problem and a new performance measure based on the Circular Earth Movers‟ Distance.
Results from the investigations involving an intransitive number problem, multimodal problem and two red teaming scenarios showed that in terms of the performance measures used, there is not a single algorithm that consistently outperforms the others across the four test problems. Applications of CEAs on the red teaming scenarios showed that all four variants produced interesting evolved strategies at the end of the optimization process, as well as providing evidence of the potential of CEAs in their future application in red teaming.
The developed techniques can potentially be used for red teaming in military operations or analysis for protection of critical infrastructure. The benefits include the modelling of more realistic interactions between the teams, the ability to anticipate and to counteract potentially new types of attacks as well as providing a cost effective solution.
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Blázquez, Navarro Arturo. "Towards personalized medicine in kidney transplantation: Unravelling the results of a large multi-centre clinical study." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21322.
Full textAbstract:
Trotz Fortschritte in den letzten Dekaden ist das Langzeitüberleben von Nierentransplantaten unzureichend. Die Personalisierung der Behandlung kann dabei zu erheblichen Verbesserungen führen. Vor diesem Hintergrund wurde eine Kohorte von 587 Patienten im ersten Jahr nach der Transplantation untersucht und ein breites Spektrum von Markern zur langfristigen Prognose etabliert. In dieser Dissertation beschreibe ich in vier Manuskripten und zwei Kapiteln meine Arbeit zur personalisierten Transplantationsmedizin.
Der klinische Verlauf von Patienten nach Nierentransplantation wurde untersucht. Die wichtigen Komplikationen standen im Vordergrund: Virusreaktivierungen – insbesondere die BK- und Cytomegalieviren – und akute Abstoßung. Folgende Analysen wurden durchgeführt: (i) Systematische Analyse der Assoziationen zwischen Virusreaktivierungen und deren Einfluss auf das Transplantationsergebnis; (ii) Bewertung der Auswirkungen antiviraler Behandlungsstrategien auf die Transplantationsergebnisse; (iii) Entwicklung eines Tools zur Prätransplantations-Risikoeinschätzung der Abstoßung und (iv) Erstellung eines mathematischen Modells für die personalisierte Charakterisierung der Immunantwort gegen das BK-Virus.
Zusammengenommen haben die vier Studien das Potenzial, (i) die Patientenversorgung zu verbessern, (ii) die Überwachung von Virusreaktivierungen zu optimieren, (iii) Präventionsstrategien gegen virale Reaktivierungen zu stratifizieren, (iv) die Behandlung der Patienten an das individuelle Risiko akuter Abstoßung anzupassen, und (v) zur Personalisierung der Immuntherapie beizutragen. Die Studien zeigen, wie das große Datenvolumen einer klinischen Studie zur Weiterentwicklung der personalisierten Medizin unter Einsatz effektiver Strategien für Datenmanagement, Analyse und Interpretation genutzt werden kann. Es ist zu erwarten, dass diese Ergebnisse die klinische Praxis beeinflussen und so das langfristige Überleben und die Lebensqualität der Patienten verbessern.<br>In spite of the developments in the last decades, long-term graft survival rates in kidney transplantation are still poor: Personalization of treatment can thereby lead to a drastic improvement in long-term outcomes. With this goal, a cohort of 587 patients was characterized for a wide range of markers during the first post-transplantation year to assess their long-term prognosis. Here, I describe along four manuscripts and two chapters my work on personalized medicine for renal transplantation.
In detail, we have studied the clinical evolution of patients with emphasis on two most relevant complications: viral reactivations – particularly those of BK virus and cytomegalovirus – and acute rejection. We have analysed in depth these phenomena by (i) exhaustively analysing the associations between different viral reactivations and their influence on transplantation outcome, (ii) evaluating the effects of antiviral treatment strategies on viral reactivation and other transplantation outcomes with emphasis on sex-associated differences, (iii) developing a tool for the pre-transplantation risk assessment of acute cellular rejection, and (iv) creating a mathematical model for the personalized characterization of the immune response against the BK virus under immunosuppression.
Taken together, these studies have the potential of improving patient care, optimizing monitoring of viral reactivations, stratifying antiviral prevention strategies, tailoring immunosuppression and monitoring to the individual risk of acute rejection, and contributing to personalization of immunotherapy. They demonstrate how the large volume of data obtained within a clinical study can be employed to further the development of personalized medicine, employing effective data management, analysis and interpretation strategies. We expect these results to eventually inform clinical practice, thereby improving long-term survival and quality of life after kidney transplantation.
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Nekkab, Narimane. "Spread of hospital-acquired infections and emerging multidrug resistant enterobacteriaceae in healthcare networks : assessment of the role of interfacility patient transfers on infection risks and control measures." Thesis, Paris, CNAM, 2018. http://www.theses.fr/2018CNAM1180/document.
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The spread of healthcare-associated infections (HAIs) and multi-drug resistance in healthcare networks is a major public health issue. Evaluating the role of inter-facility patient transfers that form the structure of these networks may provide insights on novel infection control measures. Identifying novel infection control strategies is especially important for multi-drug resistant pathogens such as Carbapenemase-producing Enterobacteriaceae (CPE) due to limited treatment options. The increasing use of inter-individual contact and inter-facility transfer network data in mathematical modelling of HAI spread has helped these models become more realistic; however, they remain limited to a few settings and pathogens. The main objectives of this thesis were two-fold: 1) to better understand the structure of the healthcare networks of France and their impact on HAI spread dynamics; and 2) to assess the role of transfers on the spread of CPE in France during the 2012 to 2015 period. The French healthcare networks are characterized by centralized patient flows towards hubs hospitals and a two-tier community clustering structure. We also found that networks of patients with HAIs form the same underlying structure as that of the general patient population. The number of CPE episodes have increased over time in France and projections estimate that the number of monthly episodes could continue to increase with seasonal peaks in October. The general patient network was used to show that, since 2012, patient transfers have played an increasingly important role over time in the spread of CPE in France. Multiple spreading events of CPE linked to patient transfers were also observed. Despite subtle differences in the flows of patients with an HAI and the general patient population, the general patient network may best inform novel infection control measures for pathogen spread. The structure of healthcare networks may help serve as a basis for novel infection control strategies to tackle HAIs in general but also CPE in particular. Key healthcare hubs in large metropoles and key patient flows connecting hospital communities at the local and regional level should be considered in the development of coordinated regional strategies to control pathogen spread in healthcare systems<br>La propagation des infections nosocomiales (IN), notamment liées aux bactéries multi-résistantes, au sein du réseau des hôpitaux, est un grand enjeu de santé publique. L’évaluation du rôle joué par les transferts inter-établissements des patients sur cette propagation pourrait permettre l’élaboration de nouvelles mesures de contrôle. L’identification de nouvelles mesures de contrôle est particulièrement importante pour les bactéries résistantes aux antibiotiques comme les entérobactéries productrices de carbapenemase (EPC) pour lesquelles les possibilités de traitement sont très limitées. L’utilisation des données de réseaux de contact inter-individus et de transferts inter-établissement dans la modélisation mathématique ont rendu ces modèles plus proches de la réalité. Toutefois, ces derniers restent limités à quelques milieux hospitaliers et quelques pathogènes. La thèse a eu pour objectifs de 1) mieux comprendre la structure des réseaux hospitaliers français et leur impact sur la propagation des IN ; et 2) évaluer le rôle des transferts sur la propagation des EPC.Les réseaux hospitaliers français sont caractérisés par des flux de patients vers des hubs et par deux niveaux de communautés des hôpitaux. La structure du réseau de transfert des patients présentant une IN n’est pas différente de celle du réseau général de transfert des patients. Au cours des dernières années, le nombre d’épisode d’EPC a augmenté en France et les prédictions prévoient une poursuite de cette augmentation, avec des pics de saisonnalité en octobre. Ce travail a également montré que, depuis 2012, les transferts de patients jouent avec les années un rôle de plus en plus important sur la diffusion des EPC en France. Des évènements de propagation multiple liée aux transferts sont également de plus en plus souvent observés.En conséquence, la structure du réseau des hôpitaux pourrait servir de base pour la proposition des nouvelles stratégies de contrôles des IN en général, et des EPC en particulier. Les hôpitaux très connectés des grandes métropoles et les flux des patients entre les communautés locale et régionale doivent être considérés pour le développement de mesures de contrôle coordonnées entre établissements de santé
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Nixdorf, Erik. "Combining measurements, remote sensing and numerical modelling to assess multi-scale flow dynamics in groundwater-dependent environmental systems." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-236485.
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Groundwater flow modelling provides an important quantitative instrument for addressing issues related to the quantity and quality of groundwater and the connected water resources. Consequently, groundwater flow models have been developed and used ubiquitously in science to deepen the understanding of subsurface processes and their drivers as well as management and planning tools. The present work investigates how numerical models can be linked to field investigations and public databases to quantitatively approach questions in the area of groundwater research. The primary goal is to develop new, efficient ways to overcome limitations of the individual hydrological concepts for solving specific hydrological problems and to increase the understanding of practical applicability of different methods. For this purpose, tailor-made approaches were developed for different study areas covering diverse spatial scales: the hydrology of a small mining lake, the riparian aquifer at the scale of a single meander as well as the aquifer systems of a large-scale river basin in China. The first part of the work deals with the physical and mathematical modelling of water constituents balance in a meromictic mining lake in Lusatia. The capability of using a rather simple mass-balance model based on a sufficient dataset of field data to evaluate lake stratification and lake-groundwater interaction were shown. In the second part, a transient numerical groundwater flow model was developed for the riparian aquifer of a stream meander and was calibrated by three different salt tracer tests. The model was used to proof the reliability of subsurface travel times derived from time series analysis and to give insights in the riparian zone dynamics during changing hydraulic gradients. The third part of the work describes the methodology to conduct risk assessment of groundwater contamination on the large catchment scale of the Songhua River in China. A comprehensive literature study was conducted to get an overview about measurement data on water quality data in China. A three-dimensional numerical flow and mass transport model was applied to access the flow and matter transport dynamics in the aquifer system of a sub-basin considering changing groundwater exploitation scenarios. Consequently, numerical groundwater modelling was combined with processed remote sensing and web mapping service data to overcome field data limitations and to derive groundwater vulnerability, groundwater hazard and groundwater risk maps for the entire Songhua River Basin. Summarizing, this doctoral thesis could develop new methods of combining field measurements, data assimilation and aggregation from various sources and groundwater modelling strategies and successfully apply these methods to find solutions on problems of multiple scales and across water systems<br>Die Grundwassermodellierung stellt eine wichtige wissenschaftliche Methode zur quantitativen Analyse von Fragestellungen zum Schutz der Menge und Güte der Grundwasserressourcen sowie der angeschlossenen Wasserkörper dar. Dementsprechend werden Grundwassermodelle sowohl für Planungs- und Bewertungszwecke im Wasserressourcenmanagement als auch zur wissenschaftlichen Erforschung der Prozesse im Untergrund entwickelt und angewendet. Die vorliegende Arbeit untersucht in diesem Rahmen, wie numerische Modelle, Feldmessungen und Daten generiert aus Fernerkundungsdaten und Webplattformen systematisch verknüpft werden können, um Fragestellungen im Bereich der Grundwasserforschung quantitativ zu beantworten. Das Ziel der Arbeit ist es neue effiziente Abläufe zu entwickeln, die die Limitierung der einzelnen Methoden überwinden und diese auf deren Anwendbarkeit für die Lösung spezifischer hydrologischer Probleme zu analysieren. Zu diesem Zweck wurden in dieser Doktorarbeit fallspezifische Lösungen für verschiedene Untersuchungsgebiete entwickelt, die sowohl in der räumlichen Skale als auch in den zu untersuchenden hydrologischen Fragestellungen eine große Diversität aufweisen. Im ersten Teil der Arbeit wurde die Massenbilanz von Wasserinhaltsstoffen in einem meromiktischen Tagebaurestsee im Lausitzer Revier durch physikalische und mathematische Modellierungsmethoden untersucht. Dabei konnte gezeigt werden, dass auf Basis einer gewonnenen mehrjährigen Zeitreihe von Messdaten ein einfaches Massenbilanzmodell in der Lage ist, sowohl Seeschichtungs- als auch Grundwasseraustauschdynamiken quantitativ zu beschreiben. Der zweite Teil der Arbeit umfasst die Entwicklung eines transienten numerischen Grundwassermodells für den quartären Uferaquifer im Bereich eines Flussmäanders der Selke welches anhand von Daten aus mehreren Salztracertests kalibriert wurde. Das Modell wurde dafür verwendet die transienten Verweilzeiten in der gesättigten Zone des Mäanderbogens unter dem Einfluss dynamischer hydraulischer Bedingungen zu untersuchen. Die Ergebnisse wurden im Anschluss mit Verweilzeiten verglichen, die aus der Analyse der zeitlichen Verschiebung von gemessenen elektrischen Leitfähigkeitszeitreihen zwischen Fluss und Grundwassermessstellen gewonnen wurden. Durch dieses kombinierte Verfahren konnten sowohl die Beschränkungen der zeitreihenbasierten Verweilzeitberechnung aufgezeigt als auch ein tieferes Systemverständnis für die Interaktionsdynamiken zwischen Grund- und Flusswasser auf der Mäanderskala gewonnen werden. Der dritte Teil der Arbeit beschreibt die Vorgehensweise für die Bewertung des Grundwasserkontaminationsrisikos im Einzugsgebiet des Songhua Flusses in China. Eine umfassende Literaturstudie wurde durchgeführt, um einen Überblick über die Verfügbarkeit von Messdaten zur Belastung der Wasserressourcen Chinas mit organischen Schadstoffen zu erhalten. Danach wurde für ein Teileinzugsgebiet ein dreidimensionales numerisches Grundwassermodell auf Basis der vorhandenen hydrogeologischen Daten aufgebaut. Dieses wurde dazu verwendet die Änderungen im Stofftransports und den Schadstoffkonzentrationen innerhalb des Aquifersystems unter steigenden Entnahmeraten zu analysieren. Basierend auf diesen Studien wurden auf der Skale des Gesamteinzugsgebiets, um die beschränkte Verfügbarkeit von Felddaten auszugleichen, die Ergebnisse der numerischen Grundwassermodellierung mit Fernerkundungsdaten und Webdatenbanken in einem Indexsystem kombiniert mit dem für die oberflächennahen Aquifere Vulnerabilität, Gefährdungspotential und Verschmutzungsrisiko in einer räumlichen Auflösung von 1 km² bestimmt wurden. Zusammenfassend konnten durch die vorliegende Doktorarbeit neue passgenaue Methoden zur effektiven Kombination von in-situ Messungen, der Datenerhebung und Datenintegration aus vielfältigen Datenquellen sowie numerischen Grundwassermodellierungsstrategien entwickelt und zur Lösung der untersuchten hydrologischer Fragestellen auf den verschiedenen Skalen und über die Grenzen der einzelnen hydrologischen Teilsysteme hinaus erfolgreich angewandt werden
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Iberraken, Dimia. "Safe Trajectories and Sequential Bayesian Decision-Making Architecture for Reliable Autonomous Vehicle Navigation." Thesis, Université Clermont Auvergne (2017-2020), 2020. http://www.theses.fr/2020CLFAC043.
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Les dernières avancées en matière de conduite de véhicules autonomes (VAs) ont fait apparaître toute l'importance de garantir la fiabilité complète des manœuvres que doivent effectuer les VAs, y compris dans des environnements/situations très dynamiques et incertains. Cet objectif devient encore plus ardu en raison du caractère unique de chaque situation/condition de circulation. Pour faire face à toutes ces configurations très contraignantes et complexes, les VAs doivent disposer d'une architecture de contrôle appropriée avec des Stratégies d'Evaluation et de Gestion des Risques (SEGR) fonctionnant en temps-réel et d'une manière fiable. Ces SEGR ciblées doivent conduire à une réduction drastique des risques de conduite. Théoriquement et de maniéré systémique, ces SEGR doivent aboutir à un risque de conduite inférieur à tout comportement de conduite humaine. En conséquent, il est également question de réduire la nécessité d'effectuer des tests très poussés, qui peuvent prendre plusieurs mois/années pour au final ne pas avoir de preuves formelles de la viabilité et de la sûreté complète du système. Ainsi, les travaux présentés dans cette thèse de doctorat ont pour but d'avoir une méthodologie prouvable pour les SGER des VAs.Cette thèse porte sur l'ensemble du processus, en partant de l'évaluation des risques, de la planification de la trajectoire jusqu'à la prise de décision et au contrôle du véhicule autonome. En premier lieu, une architecture multi-contrôleurs probabiliste (Probabilistic Multi-Controller Architecture P-MCA) est conçue pour une conduite autonome sûre en présence d'incertitudes. Cette architecture est composé de plusieurs modules interconnectés qui sont responsables de : l'évaluation du risque de collision avec tous les véhicules observés tout en considérant les prévisions de leurs trajectoires ; la planification des différentes manœuvres de conduite ; la prise de décision sur les actions les plus appropriées à réaliser ; le contrôle du mouvement du véhicule ; l'interruption en toute sécurité de la manœuvre engagée si nécessaire (en raison par exemple d'un changement soudain de l'environnement routier) ; et en dernier recours la planification des actions évasives à défaut d'un autre choix. L'évaluation des risques proposée est basée sur une stratégie à deux étapes. La première étape consiste à analyser la situation actuelle de conduite et à prévoir les éventuelles collisions. Cette étape est réalisée en tenant compte de plusieurs contraintes dynamiques et des conditions de circulation connues au moment de la planification. La deuxième étape est appliquée en temps-réel, durant la réalisation de la manœuvre, où un mécanisme de vérification de la sécurité est activé pour quantifier les risques et la criticité de la situation de conduite sur le temps restant pour réaliser la manœuvre. La stratégie décisionnelle est basée sur un réseau Bayésien de décision à niveaux séquentiels pour la sélection et la vérification des manœuvres (Sequential Decision Networks for Maneuver Selection and Verification SDN-MSV) et constitue un module essentiel de l'architecture P-MCA. Ce module est conçu pour gérer plusieurs manœuvres routières dans un environnement incertain. Il utilise l'évaluation des étapes de sécurité définies pour proposer des actions discrètes qui permettent de : réaliser des manœuvres appropriées dans une situation de trafic donnée, il fournit également une rétrospective de la sécurité, cette dernière actualise en temps-réel les mouvements de l'égo-véhicule en fonction de la dynamique de l'environnement, afin de faire face à toute situation dangereuse et risquée soudaine. (...)<br>Recent advances in Autonomous Vehicles (AV) driving raised up all the importance to ensure the complete reliability of AV maneuvers even in highly dynamic and uncertain environments/situations. This objective becomes even more challenging due to the uniqueness of every traffic situation/condition. To cope with all these very constrained and complex configurations, AVs must have appropriate control architecture with reliable and real-time Risk Assessment and Management Strategies (RAMS). These targeted RAMS must lead to reduce drastically the navigation risks (theoretically, lower than any human-like driving behavior), with a systemic way. Consequently, the aim is also to reduce the need for too extensive testing (which could take several months and years for each produced RAMS without at the end having absolute prove). Hence the goal in this Ph.D. thesis is to have a provable methodology for AV RAMS. This dissertation addresses the full pipeline from risk assessment, path planning to decision-making and control of autonomous vehicles. In the first place, an overall Probabilistic Multi-Controller Architecture (P-MCA) is designed for safe autonomous driving under uncertainties. The P-MCA is composed of several interconnected modules that are responsible for: assessing the collision risk with all observed vehicles while considering their trajectories' predictions; planning the different driving maneuvers; making the decision on the most suitable actions to achieve; control the vehicle movement; aborting safely the engaged maneuver if necessary (due for instance to a sudden change in the environment); and as last resort planning evasive actions if there is no other choice. The proposed risk assessment is based on a dual-safety stage strategy. The first stage analyzes the actual driving situation and predicts potential collisions. This is performed while taking into consideration several dynamic constraints and traffic conditions that are known at the time of planning. The second stage is applied in real-time, during the maneuver achievement, where a safety verification mechanism is activated to quantify the risks and the criticality of the driving situation beyond the remaining time to achieve the maneuver. The decision-making strategy is based on a Sequential Decision Networks for Maneuver Selection and Verification (SDN-MSV) and corresponds to an important module of the P-MCA. This module is designed to manage several road maneuvers under uncertainties. It utilizes the defined safety stages assessment to propose discrete actions that allow to: derive appropriate maneuvers in a given traffic situation and provide a safety retrospection that updates in real-time the ego-vehicle movements according to the environment dynamic, in order to face any sudden hazardous and risky situation. In the latter case, it is proposed to compute the corresponding low-level control based on the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) that allows the ego-vehicle to pursue the advised collision-free evasive trajectory to avert an accident and to guarantee safety at any time.The reliability and the flexibility of the overall proposed P-MCA and its elementary components have been intensively validated, first in simulated traffic conditions, with various driving scenarios, and secondly, in real-time with the autonomous vehicles available at Institut Pascal
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Gowan, Monica Elizabeth. "Self-Management of Disaster Risk and Uncertainty: The Role of Preventive Health in Building Disaster Resilience." Thesis, University of Canterbury. Health Sciences Centre, 2011. http://hdl.handle.net/10092/7605.
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One of the great challenges facing human systems today is how to prepare for, manage, and adapt successfully to the profound and rapid changes wreaked by disasters. Wellington, New Zealand, is a capital city at significant risk of devastating earthquake and tsunami, potentially requiring mass evacuations with little or short notice. Subsequent hardship and suffering due to widespread property damage and infrastructure failure could cause large areas of the Wellington Region to become uninhabitable for weeks to months.
Previous research has shown that positive health and well-being are associated with disaster-resilient outcomes. Preventing adverse outcomes before disaster strikes, through developing strengths-based skill sets in health-protective attitudes and behaviours, is increasingly advocated in disaster research, practise, and management. This study hypothesised that well-being constructs involving an affective heuristic play vital roles in pathways to resilience as proximal determinants of health-protective behaviours. Specifically, this study examined the importance of health-related quality of life and subjective well-being in motivating evacuation preparedness, measured in a community sample (n=695) drawn from the general adult population of Wellington’s isolated eastern suburbs.
Using a quantitative epidemiological approach, the study measured the prevalence of key quality of life indicators (physical and mental health, emotional well-being or “Sense of Coherence”, spiritual well-being, social well-being, and life satisfaction) using validated psychometric scales; analysed the strengths of association between these indicators and the level of evacuation preparedness at categorical and continuous levels of measurement; and tested the predictive power of the model to explain the variance in evacuation preparedness activity. This is the first study known to examine multi-dimensional positive health and global well-being as resilient processes for engaging in evacuation preparedness behaviour.
A cross-sectional study design and quantitative survey were used to collect self-report data on the study variables; a postal questionnaire was fielded between November 2008 and March 2009 to a sampling frame developed through multi-stage cluster randomisation. The survey response rate was 28.5%, yielding a margin of error of +/- 3.8% with 95% confidence and 80% statistical power to detect a true correlation coefficient of 0.11 or greater.
In addition to the primary study variables, data were collected on demographic and ancillary variables relating to contextual factors in the physical environment (risk perception of physical and personal vulnerability to disaster) and the social environment (through the construct of self-determination), and other measures of disaster preparedness. These data are reserved for future analyses.
Results of correlational and regression analyses for the primary study variables show that Wellingtonians are highly individualistic in how their well-being influences their preparedness, and a majority are taking inadequate action to build their resilience to future disaster from earthquake- or tsunami-triggered evacuation. At a population level, the conceptual multi-dimensional model of health-related quality of life and global well-being tested in this study shows a positive association with evacuation preparedness at statistically significant levels. However, it must be emphasised that the strength of this relationship is weak, accounting for only 5-7% of the variability in evacuation preparedness.
No single dimension of health-related quality of life or well-being stands out as a strong predictor of preparedness. The strongest associations for preparedness are in a positive direction for spiritual well-being, emotional well-being, and life satisfaction; all involve a sense of existential meaningfulness. Spiritual well-being is the only quality of life variable making a statistically significant unique contribution to explaining the variance observed in the regression models. Physical health status is weakly associated with preparedness in a negative direction at a continuous level of measurement. No association was found at statistically significant levels for mental health status and social well-being. These findings indicate that engaging in evacuation preparedness is a very complex, holistic, yet individualised decision-making process, and likely involves highly subjective considerations for what is personally relevant. Gender is not a factor. Those 18-24 years of age are least likely to prepare and evacuation preparedness increases with age.
Multidimensional health and global well-being are important constructs to consider in disaster resilience for both pre-event and post-event timeframes. This work indicates a need for promoting self-management of risk and building resilience by incorporating a sense of personal meaning and importance into preparedness actions, and for future research into further understanding preparedness motivations.
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Daudin, Kevin. "Contribution à la prédiction des effets réactions sodium-eau : application aux pertes de confinement dans un bâtiment générateur de vapeur d'un réacteur à neutrons rapides refroidi au sodium." Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2212/document.
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L’étude des conséquences de la réaction sodium-eau (RSE) est un enjeu dans le cadre de la sûreté des futurs réacteurs à neutrons rapides à caloporteur sodium. Afin d'évaluer les conséquences de RSE dans des situations d'accident majeur, il est nécessaire de mieux comprendre la phénoménologie et notamment la quantité d'énergie libérée et la cinétique de libération. L'objectif est donc d’améliorer la compréhension de telles RSE pour prédire au mieux ses conséquences sur les équipements mécaniques alentours. Trois axes de travail ont été privilégiés, à savoir la recherche du déroulement des séquences accidentelles, un examen expérimental paramétrique, et une analyse de la phénoménologie avant le contact explosif. Dans un premier temps, une méthode arborescente d'analyse de risques a été croisée avec des méthodes de calcul d'effets. Cette analyse a permis d’imaginer comment le contact peut s'effectuer. Des études expérimentales démonstratives de l'influence du mode de mise en contact ont ensuite été effectuées afin d’approfondir certains aspects pratiques. L’analyse des nombreuses données recueillies conduit au développement d’un modèle d'interprétation phénoménologique, intégré dans une plateforme de simulation multi-physique. Bien que de nombreuses hypothèses simplificatrices soient réalisées, la prise en compte des transferts de chaleur transitoires permet de reproduire les observations expérimentales et notamment l'influence des conditions de mélange (masse de sodium et températures initiales) sur la phénoménologie. Ce travail d'étude de la phase de pré-mélange de l'explosion sodium-eau est pertinent au regard des méthodes de prédiction des chargements sur les structures<br>Study of sodium-water reaction (SWR) consequences in open air represents a challenge in the frame of safety assessments of sodium fast reactors (SFR). In case of major accident and to predict consequences of SWR, it is necessary to better appreciate phenomena and especially quantity and rate of the energy releasement. The objective is thus to strengthen the understanding of such reactions in order to predict with lore accuracy its consequences on mechanical equipment in the surroundings. This work focuses on three areas : research of accidental sequences, experimental investigation, and phenomenological analysis before the explosive contact. At first, a tree structure risk analysis with calculations of dangerous phenomena permitted to suggest how the contact between reactants may happen. Then, demonstrative experimental studies were performed to deepen some practical aspects of the phenomenology, like the influence of the way the reactants get in contact. Data analysis conducted to the development of a phenomenological model, implemented into a software platform for numerical simulations. Although numerous hypothesis, transient heat transfer consideration enables to reproduce experimental observations, especially the influence of mixing conditions (sodium mass and initial temperatures) on the phenomenology. This study of the premixing step of sodium-water explosion is relevant in the frame of current prediction methods of mechanical loadings on structures
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El, Mokrini Asmae. "Strategic redesign of pharmaceutical’s distribution network in the public sector of Morocco." Electronic Thesis or Diss., Paris 8, 2018. http://www.theses.fr/2018PA080097.
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Cette recherche a pour objectif la refonte de la supply chain des produits pharmaceutiques destinés au secteur public au niveau stratégique en prenant en considération l’accessibilité des citoyens au système de santé. Elle a été tirée de la nécessité de repenser la chaîne d’approvisionnement des produits pharmaceutiques au Maroc. Ainsi, les principales actions recommandées pour atteindre les objectifs de cette recherche ont été résumées dans les axes principaux suivants. Nous avons commencé par l’étude et l’analyse de la supply chain existante et le développement de décisions stratégiques en relation avec la structure du réseau de distribution. La contribution de ce travail consiste à proposer une application de l’analyse de décision multicritères pour évaluer un ensemble de réseaux de distribution alternatifs pour les produits pharmaceutiques et sélectionner le plus approprié. Les résultats finaux montrent que le réseau de distribution décentralisé est le réseau le plus approprié selon les préférences des parties prenantes du ministère de la Santé. Le deuxième axe concerne la détermination des emplacements d’entrepôt optimaux pour le réseau décentralisé. Nous avons présenté un modèle de localisation des installations qui est une variante du problème de couverture qui prend en compte les caractéristiques spécifiques d’un pays émergent. Les résultats montrent comment le type d’infrastructure routière et la distribution de la demande affectent le nombre d’entrepôts et leurs emplacements. Le troisième axe aborde l’étude de la faisabilité de l’externalisation de la logistique. L’un des résultats de cette partie de la dissertation est un processus d’aide à la décision pour l’internalisation et l’externalisation stratégique au sein d’une organisation. Il vise à guider les acteurs de différents domaines dans le processus de prise de décision en ce qui concerne leurs fonctions logistiques. Dans le cadre de ce cadre décisionnel, l’évaluation des risques contribue dans une large mesure à l’évaluation de la faisabilité de l’externalisation. Nous avons pu élaborer une approche d’évaluation des risques qui nous aidera à évaluer la criticité des risques. Le modèle permet aux chercheurs et aux praticiens de comprendre l’importance de mener une évaluation des risques appropriée lors de la mise en oeuvre des initiatives d’externalisation<br>This research is aimed to redesign the supply chain of pharmaceuticals on the strategic level as a result of taking into consideration the issues related to citizen’s right to healthcare. It has been drawn from the need to redesign the supply chain of pharmaceuticals in Morocco. Thus, the main actions recommended in order to achieve the objectives of this research were summarized in the following main axes. We started with the study and analysis of the supply chain existing on the physical infrastructure and the development of strategic decisions in relation to the structure of the distribution network. The contribution of this work lays in proposing an application of multi-criteria decision analysis to evaluate a set of alternative distribution networks for pharmaceuticals and select the most appropriate one. Final results show that decentralized distribution network is the most appropriate network according to the Ministry of Health stakeholder’s preferences. The second axis deals with the determination of optimal warehouse locations for the decentralized network. We presented a facility location model which is a variant of the set covering problem that takes into consideration specific characteristics of an emerging market. The results show how the road infrastructure type and demand dispersion affect the number of warehouses and their locations. The third axis tackles the investigation of the feasibility of outsourcing logistics. One of the outputs of this part of the dissertation is a decision aid process for strategic insourcing/outsourcing within an organization. It aims at guiding stakeholders from different domains in the process of decision making with regards to their logistics functions. As part of this decision framework, risk assessment contributes to a large extent in the evaluation of the feasibility of outsourcing. We were able to elaborate an approach for risk evaluation that will help us evaluate the criticality of risks. The model enables researchers and practitioners understand the importance of conducting appropriate risk assessment when implementing outsourcing initiatives
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Duncan, M. J. "Multi-hazard assessments for disaster risk reduction : lessons from the Philippines and applications for non-govermental organisations." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1452516/.
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Disaster risk reduction (DRR) should be underpinned by multi-hazard assessments that integrate community and scientific knowledge. Humanitarian and development non-governmental organisations (NGOs) are key implementers of DRR, but there is little guidance for them regarding the requirements of a multi-hazard approach. Using mainly qualitative methods, a conceptual framework for multi-hazards is proposed, which emphasises the interrelations between hazards as well as the need to address more than one hazard. This framework is compared to existing NGO hazard assessment methods at Head Office and in the Philippines (a multi-hazard hotspot), along with a case study of the 2006 Typhoon Reming lahars disaster at Mayon Volcano. Throughout the research, the role of scientific knowledge is explored. Interviewees assume that their community-based assessments ‘toolkits’ capture multi-hazards, but these are constrained by preconceptions related to DRR, the confined temporal and spatial scales of analysis and the emphasis on community knowledge. Particularly amongst Head Office NGOs, the need for science and a more anticipatory approach is driven by climate change adaptation rather than DRR. However, the Reming lahars disaster emphasises that DRR strategies must anticipate, prepare for and respond to simultaneous hazards, whilst accounting for how previous hazards might amplify or alleviate the anticipated event. The disaster emphasises the limits of community knowledge but also those of the available science, along with the need for good communication between scientists, NGOs and communities. The conceptual multi-hazard framework provides NGOs with a multi-hazard ‘lens’ to their analyses, but the findings emphasise that multi-hazard assessments require more than a toolkit. NGOs need the skills to access, understand and evaluate science and engage with scientists. There are numerous ideological and practical barriers to integrating science, which are partly addressed by a set of practical guidelines developed alongside the research. Beyond NGOs, the research has important implications for DRR policy.
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Lindqvist, Björn. "Multi-axis industrial robot braking distance measurements : For risk assessments with virtual safety zones on industrial robots." Thesis, Högskolan Väst, Avdelningen för produktionssystem (PS), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-11447.
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Industrial robots are increasingly used within the manufacturing industry, especially in collaborative applications, where robots and operators are intended to work together in certain tasks. This collaboration needs to be safe, to ensure that an operator does not get injured in any way. One of several solutions to this is to use virtual safety zones, which limits the robots working range and area to operate within, and may be more flexible than physical fences. When the robot exceeds the allowed limit of the virtual safety zone, a control system that monitors the robot position, forces to robot to stop. Depending on the current speed and payload of the robot, the initialized stop has a braking distance until the robot has completely stopped. How far the separation distance between human and robot must be, is calculated using ISO-standard guidelines when doing risk assessments. To support affected personnel in their work, an investigation and experimentation of braking distances among several robots has been conducted. These testing experiments have been designed to simulate a collaborative operation which is an excessive risk in a robot cell. The tests have been performed with various speeds and payloads, for comparison between the robot models and for validation against already existing data. The difference with this study compared to existing ones is that several robot axis’ are used simultaneously in the testing movements, which is a benefit since a robot rarely operates with only one axis at a time. Main results of the performed tests are that the robot doesn’t obtain speeds over 2000 mm/s when axis 1 is not involved, before the virtual safety zone is reached. Axis 1 can generate the highest speeds overall, and is therefore a significant factor of the braking distance. The results and conclusions from this thesis states that these kinds of tests give useful information to the industry when it comes to safety separation distance and risk assessments. When applying the information in a correct way, the benefits are that a shorter safety separation distance can be used without compromising on safety. This leads to great advantages in robot cell design, because space is limited on the factory floor.
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Vo, Ngoc Duong. "Modélisation hydrologique déterministe pour l'évaluation des risques d'inondation et le changement du climat en grand bassin versant. Application au bassin versant de Vu Gia Thu Bon, Viet Nam." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4056/document.
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Le changement climatique dû à l'augmentation des émissions de gaz à effet de serre est considéré comme l'un des principaux défis pour les êtres humains dans 21ème siècle. Il conduira à des changements dans les précipitations, l'humidité atmosphérique, augmentation de l'évaporation et probablement augmenter la fréquence des événements extrêmes. Les conséquences de ces phénomènes auront une influence sur de nombreux aspects de la société humaine. Donc, il y a une nécessité d'avoir une estimation robuste et précise de la variation des facteurs naturels dus au changement climatique, au moins dans les événements de cycle et d'inondation hydrologiques pour fournir une base solide pour atténuer les impacts du changement climatique et s'adapter à ces défis. Le but de cette étude est de présenter une méthodologie pour évaluer les impacts de différents scénarios de changement climatique sur une zone inondable du bassin de la rivière côtière dans la région centrale du Viet Nam - bassin versant de Vu Gia Thu Bon. Les simulations hydrologiques sont basées sur un modèle hydrologique déterministe validé qui intègre la géologie, les sols, la topographie, les systèmes fluviaux et les variables climatiques. Le climat de la journée présente, sur la période de 1991-2010 a été raisonnablement simulée par le modèle hydrologique. Climat futur (2091-2100) information a été obtenue à partir d'une réduction d'échelle dynamique des modèles climatiques mondiaux. L'étude analyse également les changements dans la dynamique des inondations de la région de l'étude, le changement hydrologique et les incertitudes du changement climatique simulation<br>Climate change due to the increase of greenhouse gas emissions is considered to be one of the major challenges to mankind in the 21st century. It will lead to changes in precipitation, atmospheric moisture, increase in evaporation and probably a higher frequency of extreme events. The consequences of these phenomena will have an influence on many aspects of human society. Particularly at river deltas, coastal regions and developing countries, the impacts of climate change to socio-economic development become more serious. So there is a need for a robust and accurate estimation of the variation of natural factors due to climate change, at least in the hydrological cycle and flooding events to provide a strong basis for mitigating the impacts of climate change and to adapt to these challenges. The aim of this study is to present a methodology to assess the impacts of different climate change scenarios on a flood prone area of a coastal river basin in the central region of Viet Nam – Vu Gia Thu Bon catchment. The hydrological simulations are based on a validated deterministic hydrological model which integrates geology, soil, topography, river systems and climate variables. The present day climate, over the period of 1991-2010 was reasonably simulated by the hydrological model. Future climate (2091-2100) information was obtained from a dynamical downscaling of the global climate models. The study also analyzes the changes in the flood dynamics of the study region, the hydrological shift and the uncertainties of climate change simulation
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Suescun, Juliana Ruiz. "Courbes de fragilité pour les ponts au Québec tenant compte du sol de fondation." Mémoire, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/1576.
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Abstract : Fragility curves are a very useful tool for seismic risk assessment of bridges. A fragility curve describes the probability of a structure being damaged beyond a specific damage state for different levels of ground shaking. Since more than half of all bridges in the province of Quebec (Canada) are in service for more than 30 years and that these bridges were designed at that time without seismic provisions, generating fragility curves for these structures is more than necessary. These curves can be used to estimate damage and economic loss due to an earthquake and prioritize repairs or seismic rehabilitations of bridges. Previous studies have shown that seismic damage experienced by bridges is not only a function of the epicentral distance and the severity of an earthquake but also of the structural characteristics of the bridge and the soil type on which it is built. Current methods for generating fragility curves for bridges do not account for soil conditions. In this work, analytical fragility curves are generated for multi-span continuous concrete girder bridges, which account for 21% of all bridges in Quebec, for the different soil profile types specified in the Canadian highway bridge design code (CAN/CSA-S6-06). These curves take into account the different types of abutment and foundation specific to these bridges. The fragility curves are obtained from time-history nonlinear analyses using 120 synthetic accelerograms generated for eastern Canadian regions, and from a Monte Carlo simulation to combine the fragility curves of the different structural components of a bridge||Résumé : Les courbes de fragilité sont un outil très utile pour l’évaluation du risque sismique des ponts. Une courbe de fragilité représente la probabilité qu'une structure soit endommagée au-delà d'un état d'endommagement donné pour différents niveaux de tremblement de terre. Étant donné que plus de la moitié des ponts dans la province de Québec (Canada) ont plus de 30 années de service et que ces ponts n'ont pas été conçus à l'époque à l'aide de normes sismiques, la génération de courbes de fragilité pour ces structures est plus que nécessaire. Ces courbes peuvent servir à estimer les dommages et les pertes économiques causés par un tremblement de terre et à prioriser les réparations ou les réhabilitations sismiques des ponts. Des études antérieures ont montré que l'endommagement subi par les ponts suite à un tremblement de terre n'est pas seulement fonction de la distance de l'épicentre et de la sévérité du tremblement de terre, mais aussi des caractéristiques structurales du pont et du type de sol sur lequel il est construit. Les méthodes actuelles pour générer les courbes de fragilité des ponts ne tiennent pas compte des conditions du sol. Dans ce travail de recherche, des courbes de fragilité analytiques sont générées pour les ponts à portées multiples à poutres continues en béton armé, soit pour 21% des ponts au Québec, pour les différents types de sol spécifiés dans le Code canadien sur le calcul des ponts routiers (CAN/CSA-S6-06). Ces courbes prennent en compte les différents types de culée et de fondation spécifiques à ces ponts. Les courbes de fragilité sont obtenues à partir d'analyses temporelles non linéaires réalisées à l'aide de 120 accélérogrammes synthétiques généres pour l’est du Canada, et d'une simulation de Monte Carlo pour combiner les courbes de fragilité des différentes composantes du pont.