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1
Savage, David A. "Decision making under pressure : a behavioural economics perspective". Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/64106/1/David_Savage_Thesis.pdf.
Abstract (sommario):
This research investigates the decision making process of individuals from revealed preferences in extreme environments or life-and-death situations, from a behavioral economics perspective. The empirical analysis of revealed behavioral preferences shows how the individual decision making process can deviate from the standard self-interested or “homo economicus” model in non-standard situations. The environments examined include: elite athletes in FIFA World and Euro Cups; climbing on Everest and the Himalaya; communication during 9/11 and risk seeking after the 2011 Brisbane floods. The results reveal that the interaction of culture and environment has a significant impact on the decision process, as social behaviors and institutions are intimately intertwined, which govern the processes of human behavior and interaction. Additionally, that risk attitudes are not set and that immediate environmental factors can induce a significant shift in an individuals risk seeking behaviors.
2
Smith, Charles Adams Plater. "Decision-making under time pressure: The effects of time pressure on information search strategy, decision strategy, consistency, and outcome quality". Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185066.
Abstract (sommario):
The design of information systems to support crisis management can be improved when more is known about the ways in which people process information under time pressure. A laboratory experiment was conducted to investigate the effects of time pressure on decision behavior. The decision task required the subjects to use a computerized information display to search for information under time pressure. When the time limit for searching expired, the subjects were required to make a decision. The decision task type, choice or judgment, and three separate information display formats were also manipulated. A total of 144 student subjects were randomly assigned to the resulting six combinations of task/display treatments. Each subject performed the decision task at three levels of time pressure. Dependent measures included information search strategy, decision strategy, decision consistency, and decision quality. Analyses of the results suggest that time pressure had no effect on the information search strategy or the decision strategy. For five of the six task/display groups, time pressure was inversely related to consistency and quality. One group exhibited an inverted U relationship between time pressure and consistency. Display format had an effect on information search strategy. Task type had an effect on both consistency and quality; the performances of the choice groups were superior to those of the judgment groups. The implications of these findings with respect to the design of information systems is discussed.
3
Brooks, Scott M. "Decision making under time pressure : examination within a job interview context /". The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487775034177871.
4
Dickter, David Nathan. "The role of time orientation in decision-making under time pressure /". The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946103565876.
5
Dickter, David N. "The role of time orientation in decision making under time pressure". Connect to resource, 1997. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1250528229.
6
Marshall, Alyssa. "Toward a Model of Team Decision Making Under Stress". Honors in the Major Thesis, University of Central Florida, 2014. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1621.
Abstract (sommario):
Today’s organizations are increasingly relying on teams, rather than individuals, to complete tasks in the workplace. For some teams, these tasks require them to make high stakes
decisions under stressful conditions. In military, medical, and emergency response fields, for example, workers are regularly asked to make decisions under high time pressure, uncertainty, and risk. The purpose of this study is to summarize previous team decision-making perspectives and create a model for team decision-making under stress. A literature review was conducted to examine the current state of team decision-making research. Several existing models of the team decision-making process were identified, representing multiple decision-making perspectives. Using this information, four primary characteristics of the team decision making process were identified. Team decision making
appears to be multi-level, multi-phasic, dynamic, and cyclical process. An additional search examined the effects of stress on performance. Using this information and the characteristics outlined from the team decision making literature, a model was designed to describe the effects of stress on team decision making. This model offers several propositions regarding the effects of stress on specific cognitive and team processes and their relationship team decision making This study provides the theoretical basis for an empirical investigation of the relationship between stress and team decision making. This line of research has the potential to lead to practical solutions that may improve outcomes for workers in high stress occupations.B.S.
Bachelors
Psychology
Sciences
7
Stone, Thomas M. "Model development decisions under uncertainty in conceptual design". Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44835.
Abstract (sommario):
Model development decisions are an important feature of engineering design. The quality of simulation models often dictates the quality of design decisions, seeing as models guide decision makers (DM) in choosing design decisions. A quality model accurately represents the modeled system and is helpful for exploring what-if scenarios, optimizing design parameters, estimating design performance, and predicting the effect of design changes. However, obtaining a quality model comes at a cost in terms of model development--in experimentation, labor, model development time, and simulation time. Thus, DMs must make appropriate trade-offs when considering model development decisions.
The primary challenge in model development is making decisions under significant uncertainty. This thesis addresses model development in the conceptual design phase where uncertainty levels are high. In the conceptual design phase, there are many information constraints which may include an incomplete requirements list, unclear design goals, and/or undefined resource constrains. During the embodiment design phase, the overall objective of the design is more clearly defined, and model development decisions can be made with respect to an overall objective function. For example, the objective may be to maximize profit, where the profit is a known function of the model output. In the conceptual design phase, this level of clarity is not always present, so the DM must make decisions under significant model uncertainty and objective uncertainty. In this thesis, conjoint analysis is employed to solicit the preferences of the decision maker for various model attributes, and the preferences are used to formulate a quasi-objective function during the conceptual design phase--where the overall design goals are vague. Epistemic uncertainty (i.e., imprecision) in model attributes is represented as intervals and propagated through the proposed model development framework.
The model development framework is used to evaluate the best course of action (i.e., model development decision) for a real-world packaging design problem. The optimization of medical product packaging is assessed via mass spring damper models which predict contact forces experienced during shipping and handling. Novel testing techniques are employed to gather information from drop tests, and preliminary models are developed based on limited information. Imprecision in preliminary test results are quantified, and multiple model options are considered. Ultimately, this thesis presents a model development framework in which decision makers have systematic guidance for choosing optimal model development decisions.
8
Lundström, Anton, e Hugo Andersson. "Nyckeln till self-efficacy : Beslutsfrihet, stress från föräldrar och optimism under sena tonåren". Thesis, Mälardalens högskola, Akademin för hälsa, vård och välfärd, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-28395.
Abstract (sommario):
Enligt Bandura (1997) är self-efficacy tron på den egna förmågan att slutföra uppgifter och nå mål. Denna studie undersökte sambandet mellan upplevd beslutsfrihet under sena tonåren, upplevd stress från föräldrar under sena tonåren, upplevd optimism under sena tonåren och self-efficacy. Stickprovet på 133 studenter, varav 35 män och två av okänt kön skattade sina upplevelser och self-efficacy. En multipel hierarkisk regressionsanalys visade att self-efficacy korrelerade positivt med både beslutsfrihet och optimism vilket gav stöd för hypotes 1 och 3. Variationen i de oberoende variablerna och kontrollvariablerna kunde förklara 12% av variationen i self-efficacy. Sambandet mellan hög self-efficacy och hög upplevd grad av beslutsfrihet under sena tonåren förklarades som socialt stöd i form av tillit från föräldrarna. Sambandet mellan self-efficacy och upplevd grad av optimism under sena tonåren förklarades som att optimism ökar prestationen och chansen för framgångar. Studien föreslog att föräldrar bör ge sina tonåringar beslutsfrihet för att stärka self-efficacy.
9
Hunt, Laurence T. "Modelling human decision under risk and uncertainty". Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:244ce799-7397-4698-8dac-c8ca5d0b3e28.
Abstract (sommario):
Humans are unique in their ability to flexibly and rapidly adapt their behaviour and select courses of action that lead to future reward. Several ‘component processes’ must be implemented by the human brain in order to facilitate this behaviour. This thesis examines two such components; (i) the neural substrates supporting action selection during value- guided choice using magnetoencephalography (MEG), and (ii) learning the value of environmental stimuli and other people’s actions using functional magnetic resonance imaging (fMRI). In both situations, it is helpful to formally model the underlying component process, as this generates predictions of trial-to-trial variability in the signal from a brain region involved in its implementation. In the case of value-guided action selection, a biophysically realistic implementation of a drift diffusion model is used. Using this model, it is predicted that there are specific times and frequency bands at which correlates of value are seen. Firstly, there are correlates of the overall value of the two presented options, and secondly the difference in value between the options. Both correlates should be observed in the local field potential, which is closely related to the signal measured using MEG. Importantly, the content of these predictions is quite distinct from the function of the model circuit, which is to transform inputs relating to the value of each option into a categorical decision. In the case of social learning, the same reinforcement learning model is used to track both the value of two stimuli that the subject can choose between, and the advice of a confederate who is playing alongside them. As the confederate advice is actually delivered by a computer, it is possible to keep prediction error and learning rate terms for stimuli and advice orthogonal to one another, and so look for neural correlates of both social and non-social learning in the same fMRI data. Correlates of intentional inference are found in a network of brain regions previously implicated in social cognition, notably the dorsomedial prefrontal cortex, the right temporoparietal junction, and the anterior cingulate gyrus.
10
Haddad, Marcel Adonis. "Nouveaux modèles robustes et probabilistes pour la localisation d'abris dans un contexte de feux de forêt". Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLD021.
Abstract (sommario):
A cause du réchauffement climatique, le nombre et l’intensité des feux de forêts augmentent autour du globe. Dansce contexte, la construction de refuges contre le feu est une solution de plus en plus envisagée. Le problème consisteessentiellement à localiser p refuges de sorte à minimiser la distance maximale qui sépare un usager du plus procherefuge accessible en cas de feux. Le territoire considéré est divisé en zones et est modélisé comme un graphe auxarêtes pondérées. Un départ de feux sur une seule zone (c’est-à-dire sur un sommet). La principale conséquence d’unfeu est que les chemins d’évacuation sont modifiés de deux manières. Premièrement, un chemin d’évacuation ne peutpas traverser le sommet en feu. Deuxièmement, le fait qu’une personne proche de l’incendie puisse avoir un choix limitéde direction d’évacuation, ou être sous stress, est modélisé à l’aide d’une stratégie d’évacuation nouvellement définie.Cette stratégie d’évacuation induit des distances d’évacuation particulières qui rendent notre modèle spécifique. Selon letype de données considéré et l’objectif recherché, nous proposons deux problèmes avec ce modèle: le Robust p-CenterUnder Pressure et le Probabilistic p-Center Under Pressure. Nous prouvons que ces deux problèmes sont NP-difficilessur des classes de graphes pertinentes pour notre contexte. Nous proposons également des résultats d’approximationet d’inapproximation. Finalement, nous développons des algorithmes polynomiaux sur des classes de graphes simples,et nous développons des algorithmes mathématiques basés sur la programmation linéaireThe location of shelters in different areas threatened by wildfires is one of the possible ways to reduce fatalities in acontext of an increasing number of catastrophic and severe forest fires. The problem is basically to locate p sheltersminimizing the maximum distance people will have to cover to reach the closest accessible shelter in case of fire. Thelandscape is divided in zones and is modeled as an edge-weighted graph with vertices corresponding to zones andedges corresponding to direct connections between two adjacent zones. Each scenario corresponds to a fire outbreak ona single zone (i.e., on a vertex) with the main consequence of modifying evacuation paths in two ways. First, an evacuationpath cannot pass through the vertex on fire. Second, the fact that someone close to the fire may have limited choice, ormay not take rational decisions, when selecting a direction to escape is modeled using a new kind of evacuation strategy.This evacuation strategy, called Under Pressure, induces particular evacuation distances which render our model specific.We propose two problems with this model: the Robust p-Center Under Pressure problem and the Probabilistic p-CenterUnder Pressure problem. First we prove hardness results for both problems on relevant classes of graphs for our context.In addition, we propose polynomial exact algorithms on simple classes of graphs and we develop mathematical algorithmsbased on integer linear programming
11
Junior, Etienne Américo Cartolano. "A model for trust under a suitcase word perspective". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-16082017-151433/.
Abstract (sommario):
Trust is a social phenomenon fundamental to relationships and a building block of our society. People experience it daily, such as in a borrowing between friends, in an e-commerce transaction, in a mother-son relationship, in a connection between autonomous agents, or to show faith in God (\"In God we trust\"). In the specific case of Biodiversity domain, trust is one of the pillars of the Citizen Science projects, which are helping to solve the lack of biodiversity data by engaging citizens to work as volunteers to address this problem. Measuring and simulating levels of trust on these projects might reveal or anticipate losses; for example, the disposal of data because a deficit of trust on the technical capacity of the volunteers, opening an opportunity to manage and improve it. However, trust is a hard concept to define. The word \'trust\' may carry different meanings, such as honesty, security, integrity, competence, etc. and this is an attribute of the \'suitcase words\'. Adopting the \'suitcase\' perspective would change the way as we define, model, and simulate trust, once people would identify, decode, and simulate many meanings of trust with a single approach. In this scenario, the main objective of our research was to verify the hypotheses 1) that trust is a suitcase word, and 2) that trust can be modeled and simulated under a suitcase word perspective. A network analysis of the Web of Science citation database was able to confirm the hypothesis that trust is a suitcase word, since a distribution analysis of articles showed that trust occurs across a wide range of disciplines, and since co-occurrence maps of keywords showed that trust meanings from these disciplines may be significantly different. To verify the second hypothesis, we proposed a framework to manage trust with three components: 1) a suitcase model to identify different meanings of trust, which is the main purpose of this work, 2) a procedure to detail trust situations in terms of the suitcase model, and 3) a behavioral decision model of confidence, which was required for our simulation, since trust and control play complementary roles in the development of confidence, and consequently, to generate a confident behavior to cooperate. In our suitcase model the decision to trust (or distrust) the trustee depends on the trustors\' general capacity to take risks (= trustfulness) and on the assessment of trustee\'s interests and capacity to behavior as the trustor expects (= trustworthiness). In a practical and workable way, trustworthiness was considered a function of the trustor\'s expectations (expected evidence) and the trustee\'s previous behavior (collected evidence) for each situation. We proposed a formalism to the suitcase model, and then replicated the PlayGround simulator to modify it and incorporate our model. The new simulator, the PlayGround 2.0, was used to run a case study using trust situations from Citizen Science projects. Our main goal with this case study was to test the hypothesis that trust can be simulated under a suitcase perspective. A successful simulation would plot agents in the field reacting differently according to each situation. Results were as expected, what demonstrated the comprehensive utility of our model, with potential to handle different meanings of trust in the context of Citizen Science in the Biodiversity domain.Trust, que em português não possui uma tradução que reflita a sua complexidade, é um fenômeno fundamental para os relacionamentos e uma peça fundamental da nossa sociedade. Trust é vivenciada diariamente pelas pessoas, seja em um empréstimo entre amigos, em uma transação de comércio eletrônico, na relação entra uma mãe e um filho, na conexão entre agentes autônomos, ou para demonstrar a nossa fé. No caso específico da ciência da Biodiversidade, trust é um dos pilares dos projetos de Ciência Cidadã, que ajudam a resolver a falta de dados de biodiversidade engajando cidadãos para trabalhar como voluntários para solucionar o problema. Medir e simular trust nestes projetos pode revelar ou antecipar perdas, por exemplo, o descarte de dados devido à falta de trust na capacidade técnica dos voluntários, abrindo oportunidades para sua gestão e incentivo. Contudo, trust é um conceito difícil de definir. A palavra pode carregar muitos significados, tais como honestidade, segurança, integridade, competência, etc., e esta é uma característica das suitcase words (palavras-mala). Adotar uma perspectiva de suitcase pode mudar a maneira como definimos, modelamos e simulamos trust, pois as pessoas poderiam identificar, decodificar, e simular vários significados de trust com uma única abordagem. Neste cenário, o objetivo principal desta pesquisa foi verificar as hipóteses de que 1) trust é uma suitcase word e de que 2) trust pode ser modelada e simulada em uma perspectiva de suitcase com potencial para manipulação de diferentes significados. Uma análise de distribuição utilizando o banco de dados Web of Science foi suficiente para confirmar a primeira hipótese de que trust é uma suitcase word, pois uma análise dos seus registros de citações mostrou que trust é estudado por muitas disciplinas da ciência, e além disso, mapas de co-ocorrência de palavraschaves mostraram que os significados de trust nas disciplinas podem ser diferentes. Para verificar a segunda hipótese, nós propusemos um framework com três componentes: 1) um \'modelo suitcase\' para identificar diferentes significados de trust, que é o objetivo principal deste trabalho, 2) um procedimento para detalhar as situações de trust em componentes do modelo suitcase, e 3) um modelo de decisão comportamental sobre confiança, que foi necessário para nossa simulação, uma vez que trust e controle tem papéis complementares no desenvolvimento da confiança, e consequentemente, na exibição de um comportamento de confiança que pode levar à cooperação. No nosso modelo, a decisão de trust o trustee (aquele a quem trust é direcionada) depende da capacidade do trustor (aquele que direciona trust) em aceitar riscos (= trustfulness), e da avaliação do interesse e da capacidade do trustee em agir como o esperado (= trustworthiness). De uma maneira prática, trustworthiness foi considerada como uma função das evidências esperadas e coletadas em cada situação. Nós propusemos um formalismo para o novo modelo, e depois replicamos um simulador chamado PlayGround para depois modificá-lo e incorporar o modelo suitcase. O novo simulador, o PlayGround 2.0, foi utilizado para rodar um estudo de caso utilizando situações comuns em projetos de Citizen Science. Nosso maior objetivo foi testar a hipótese de que trust poderia ser simulada em uma perspectiva de suitcase. Uma simulação bem-sucedida plotaria os agentes em campo reagindo diferentemente de acordo com as situações apresentadas. Os resultados foram como esperados, o que demonstrou a utilidade abrangente do nosso modelo, com potencial para lidar com diferentes significados de trust no contexto dos projetos de Ciência Cidadã para Biodiversidade, ou em outros contextos.
12
Burke, Kelly Ann. "FRIEND/FOE IDENTIFICATION ACCURACY AND SHOOTING PERFORMANCE: EFFECTS OF PRIOR TASK LOADING AND TIME PRESSURE". Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3154.
Abstract (sommario):
The current dismounted soldier and the soldier of the future will be loaded' with more information processing tasks while they perform shooting tasks. It is conceivable that some increased level of cognitive tasking may be performed simultaneously with required shooting tasks. The effect of cognitive load on shooting performance has been previously examined (Scribner and Harper, 2001). This study concentrated on the effect of various cognitive workload demands on a friend-foe discrimination shooting task in a single- and dual-task scenario. In light of this, it is imperative that the soldier not be overburdened mentally, which may result in decreased survivability and lethality. Specifically, this study was designed to examine the ability of the soldier to perform friend-foe target discrimination and shooting accuracy, with varying target exposure times, friendly target signatures, and varying cognitive load demands (working memory recall task). Using the Small Arms Simulator Testbed (SAST) we examined the effects of manipulations of working memory load and sustained information transfer, on shooting performance (as measured by target acquisition and friend/foe discrimination indices). Additionally, we investigated subjective measures of workload and stress. A secondary task, administered aurally, was given to subjects to attend to while they performed shooting (friend/foe discrimination task) scenarios: working memory recall task. Each type of task consisted of three levels of difficulty. Analysis of variance revealed significant differences for the memory recall task during shooting and non-shooting conditions. Furthermore, results showed that workload increased as a function of task demand, with associated decreases in shooting performance.Ph.D.
Department of Psychology
Sciences
Psychology PhD
13
Cecchini, Lee-Anne. "Robben Island penguin pressure model: a decision support tool for an ecosystems approach to fisheries management". Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/10212.
Abstract (sommario):
Includes bibliographical references.The African penguin (Spheniscus demersus) population in southern Africa has declined from approximately 575 000 adults at the start of the 20th century to 180 000 adults in the early 1990s. The population is still declining, leading to the International Union for the Conservation of Nature upgrading the status of African penguins to Endangered on the Red List of Threatened Species. This dissertation uses a systems dynamics approach to produce a model incorporating all important pressures. The model is stochastic and spatially explicit, and uses expert opinion where data are not available. The model has been produced and revised with the help of the Penguin Modelling Group, based at the University of Cape Town. The modelling process culminated in a workshop where participants experimented with the model themselves. The model in this dissertation is only applicable to the penguin population on Robben Island and, as such, conclusions drawn cannot necessarily be applied to other penguin colonies.
14
Ibrahim, Mohamed El Hady M. "An Examination of an Integrative Expectancy Model for Auditors' Performance Behaviors Under Time Budget Pressure". Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc331382/.
Abstract (sommario):
In recent years there has been a growing use of expectancy theory to study motivation and performance in accounting environments. Such research efforts have resulted in reporting some inconsistent findings and low explanatory power for the expectancy model. In an attempt to increase the explanatory power of the model, several researchers have suggested the inclusion of nonexpectancy components in the model. This research was undertaken to develop an integrative expectancy model by incorporating some elements of goal setting theory and attribution theory into the expectancy formulation. The study was also designed to provide empirical evidence on the validity of a within-subject design of the proposed model through an empirical investigation of auditors* performance behaviors to meet budgeted time in public accounting firms. Alternative performance behaviors to meet budgeted time were modeled in three choice processes. The first deals with auditors choice to report unfiltered time (i.e. report actual time worked) as opposed to filtered time worked (i.e., underreporting and sign-off behaviors). The second process deals with auditors' choice to engage in underreporting as opposed to sign-off behaviors. The third process deals with auditors' choice to reduce or overrule some audit procedures based on professional judgment. Data were collected using an anonymous questionnaire from a sample of auditors at the staff, senior, and supervisory staff levels of fifty-three national, regional and local accounting firms in the Dallas- Fort Worth area. Data received from 671 participants were analyzed using th Automatic Interaction Detector (AID3) and multiple regression techniques. The findings of this research support the expectancy formulation and its relevancy to the accounting environments. However, five nonexpectancy variables were found to have significant relationships with auditors' choice processes to meet budgeted time. These five variables were supervision, budget feasibility, length of experience, organizational level and firm size classification.
15
Main, Daphne. "Auditor decision making under ambiguity : a test of the Einhorn and Hogarth ambiguity model". Connect to resource, 1990. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1265296896.
16
Deakin, Amanda Irene. "Decision-making under ambiguity : cognitive judgement bias in a bird and an insect model". Thesis, University of Bristol, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.761201.
17
Staats, Raymond William. "An Airspace Planning and Collaborative Decision Making Model Under Safety, Workload, and Equity Considerations". Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/26844.
Abstract (sommario):
We develop a detailed, large-scale, airspace planning and collaborative decision-making model (APCDM), that is part of an $11.5B, 10-year, Federal Aviation Administration (FAA)-sponsored effort to increase U.S. National Airspace (NAS) capacity by 30 percent. Given a set of flights that must be scheduled during some planning horizon, we use a mixed-integer programming formulation to select a set of flight plans from among alternatives subject to flight safety, air traffic control workload, and airline equity constraints.
Novel contributions of this research include three-dimensional probabilistic conflict analyses, the derivation of valid inequalities to tighten the conflict safety representation constraints, the development of workload metrics based on average (and its variance from) peak load measures, and the consideration of equity among airline carriers in absorbing the costs related to re-routing, delays, and cancellations. We also propose an improved set of flight plan cost factors for representing system costs and investigating fairness issues by addressing flight dependencies occurring in hubbed operations, as well as market factors such as schedule convenience, reliability, and the timeliness of connections.
The APCDM model has potential use for both tactical and strategic applications, such as air traffic control in response to severe weather phenomenon or spacecraft launches, FAA policy evaluation, Homeland Defense contingency planning, and military air campaign planning. The model is tested to consider various airspace restriction scenarios imposed by dynamic severe weather systems and space launch Special Use Airspace (SUA) impositions. The results from this model can also serve to augment the FAAâ s National Playbook of standardized flight profiles in different disruption-prone regions of the National Airspace.Ph. D.
18
Kantanantha, Nantachai. "Crop decision planning under yield and price uncertainties". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/24676.
Abstract (sommario):
Thesis (Ph.D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2007.Committee Co-Chair: Griffin, Paul; Committee Co-Chair: Serban, Nicoleta; Committee Member: Liang, Steven; Committee Member: Sharp, Gunter; Committee Member: Tsui, Kwok-Leung
19
Horvath, Lilla [Verfasser]. "Computational characterization of human sequential decision making under uncertainty : Model-free, model-based, exploitative and explorative strategies / Lilla Horvath". Berlin : Freie Universität Berlin, 2021. http://d-nb.info/1237685915/34.
20
Kinrade, Noel Peter. "The role of dispositional reinvestment in choking during decision-making tasks in sport". Thesis, Brunel University, 2010. http://bura.brunel.ac.uk/handle/2438/5512.
Abstract (sommario):
This thesis examines the moderating effect of dispositional reinvestment upon ‘choking’ in cognitive based tasks such as decision-making. Study 1 tested sixty-three participants’ performances on low- and high-complexity tests of motor skill, psychomotor skill and working memory under low- and high-pressure conditions. The association between reinvestment and choking was shown to extend beyond the motor skill domain to cognitive tasks, particularly those that tax working memory, with task complexity moderating this relationship. Next, a psychometric scale to identify individuals more susceptible to impaired decision-making under pressure was developed. A 13-item decision-specific version of the Reinvestment Scale (Masters, Polman, & Hammond, 1993) measuring an individual’s propensity to engage in conscious control and manifestations of ruminative thoughts emerged following factor analysis. Initial assessment of the scale’s predictive validity showed scores were highly correlated with coaches’ ratings of players’ tendency to choke. The final two studies examined choking using sport specific decision-making tasks. Initial findings were inconclusive, as choking was not observed. It was suggested the task lacked the sufficient cognitive demands to induce reinvestment. The last study, manipulating task complexity, found dispositional reinvestment to be associated with choking in the high complexity condition. The Decision-Specific Reinvestment Scale was also shown to be a better predictor of choking than the original scale. Overall, support was found for the hypothesis that Reinvestment is detrimental to performance under pressure in cognitive based tasks; however may not be the sole cause of disrupted performance. Masters and Maxwell’s (2004) concept of a working memory based explanation and Mullen and Hardy (2000) attentional threshold hypothesis offer a potential explanation to the findings.
21
Höllermann, Britta [Verfasser]. "Decision-making under uncertainty in model-based water management : The science-practice interface / Britta Höllermann". Bonn : Universitäts- und Landesbibliothek Bonn, 2018. http://d-nb.info/1167857070/34.
22
Sabet, E. "A strategic decision making model on global capacity management for the manufacturing industry under market uncertainty". Thesis, Nottingham Trent University, 2012. http://irep.ntu.ac.uk/id/eprint/113/.
Abstract (sommario):
Multi-national, large-scale and complex manufacturing systems, such as those for automotive manufacturers, often require a significant investment in production capacity, as well as great management efforts in strategic planning. Capacity-related investment decisions are often irreversible or prohibitively expensive and time-consuming to change once they are in place. Furthermore, such companies operate in uncertain business environments, which can significantly influence the optimal decisions and the systems’ performance. Therefore, a strategic question is how to globally and interactively set production resources for such systems so their optimal performance can be achieved under business uncertainty. Conventional optimisation models in this field often suffer from one or more drawbacks, such as deterministic styles, non-inclusive and non-comprehensive decision terms, non-integrated frameworks, non-empirical approaches, small size practices, local/non-global approaches or difficult-to-use methods/presentations. This research develops a new scenario-based multi-stage stochastic optimisation model, which is capable of designing and planning the production capacity for a multi-national complex manufacturing system over a long-term horizon, under demand and sales price uncertainty. Unlike many other stochastic models, this model can simultaneously optimise many strategic capacity-related decisions in an integrated framework, which helps to avoid sub-optimality. These decisions comprise capacity volume, location, relocation, merge, decomposition, product management, product-to-market decisions, product-to-plant planning, flexibility choices, etc. Furthermore, an enumerated scenario approach, which rightly fits real strategic decision making practices, has been employed in the model development. This model is also empirically designed for non-OR specialist users (managers), exploiting a programming technique and a more user-friendly input & output interface, which potentially makes the model more practical in real-scaled industrial applications. The model’s ability and its contribution to practice in real systems are demonstrated in two case studies from the automotive reference system, after a set of validations and verifications with fourteen hypothetical cases. Finally, in a systematic analysis the models’ features and abilities are compared with other newly developed analytical models and state-of-the-art researches in this field and the contribution to knowledge of this research is established.
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Lee, Keejoo. "A ceramic damage model for analyses of multi-layered ceramic-core sandwich panels under blast wave pressure loading". College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2589.
Abstract (sommario):
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Aerospace Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Karlíková, Adéla. "Modelling of flow and pressure characteristics in the model of the human upper respiratory tract under varying conditions". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413820.
Abstract (sommario):
Cílem této diplomové práce je vytvořit 3D model horních dýchacích cest podle originálního modelu segmentovaného z CT dat, aplikovat různé podmínky na průtok vzduchu v modelu, a poté hodnotit změnu charakteristik rychlosti a tlaku. Model horních dýchacích cest byl vytvořen v prostředí softwaru ANSYS, který využívá výpočetní dynamiku tekutin, a byly použity Navier-Stokesovy rovnice pro modelování průtoku vzduchu v modelu. Nejprve byl vytvořen jednoduchý 2D model za účelem seznámení se s prostředím ANSYS. Dále byl zkonstruován 3D model horních dýchacích cest a byly modelovány charakteristiky rychlosti a tlaku za různých podmínek. Tyto podmínky zahrnují různé umístění a množství míst pro odběr vzorků v modelu a výběr různých kombinací vstupů. Nakonec byly prezentovány a hodnoceny výsledky spolu s ilustracemi modelů modelovaných za různých podmínek. 3D model lze považovat ze kompromis mezi výpočetní náročností a složitostí modelu a lze jej použít jako základ pro další výzkum.
25
Shen, Gang. "Bayesian predictive inference under informative sampling and transformation". Link to electronic thesis, 2004. http://www.wpi.edu/Pubs/ETD/Available/etd-0429104-142754/.
Abstract (sommario):
Thesis (M.S.) -- Worcester Polytechnic Institute.Keywords: Ignorable Model; Transformation; Poisson Sampling; PPS Sampling; Gibber Sampler; Inclusion Probabilities; Selection Bias; Nonignorable Model; Bayesian Inference. Includes bibliographical references (p.34-35).
26
Jagelka, Tomáš. "Preferences, Ability, and Personality : Understanding Decision-making Under Risk and Delay". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX028/document.
Abstract (sommario):
Les préférences, les aptitudes et la personnalité prédisent un large éventail de réalisations économiques. Je les mets en correspondance dans un cadre structurel de prise de décision en utilisant des données expérimentales uniques collectées sur plus de 1 200 personnes prenant chacune plus de 100 décisions à enjeu financier.J’estime conjointement les distributions des préférences pour le risque et le temps dans la population, leur stabilité au niveau individuel et la tendance des gens à faire des erreurs. J’utilise le modèle à préférences aléatoires (RPM) dont il a été récemment démontré que ses propriétés théoriques sont supérieures à celles des modèles précédemment employés. Je montre que le RPM a une forte validité interne. Les cinq paramètres structurels estimés dominent un large éventail de variables démographiques et socio-économiques lorsqu'il s'agit d'expliquer des choix individuels observés.Je démontre l’importance économique et économétrique de l’utilisation des chocs aux préférences et de l’incorporation du paramètre dit de « la main tremblante ». Les erreurs et l’instabilité des préférences sont liées à des capacités différentes. Je propose un indice de rationalité qui les condense en un indicateur unique prédictif des pertes de bien-être.J'utilise un modèle à facteurs pour extraire la capacité cognitive et les « Big Five » traits de la personnalité à partir de nombreuses mesures. Ils expliquent jusqu’à 50% de la variation des préférences des gens et de leur capacité à faire des choix rationnels. La conscienciosité explique à elle seule 45% et 10% de la variation transversale du taux d'actualisation et de l'aversion au risque, ainsi que 20% de la variation de leur stabilité individuelle. En outre, l'aversion au risque est liée à l'extraversion et les erreurs dépendent des capacités cognitives, de l’effort, et des paramètres des tâches. Les préférences sont stables pour l'individu médian. Néanmoins, une partie de la population a une certaine instabilité des préférences qui est indicative d’une connaissance de soi imparfaite.Ces résultats ont des implications à la fois pour la spécification des modèles économiques de forme réduite et structurels, et aussi pour l’explication des inégalités et de la transmission intergénérationnelle du statut socio-économiquePreferences, ability, and personality predict a wide range of economic outcomes. I establish a mapping between them in a structural framework of decision-making under risk and delay using unique experimental data with information on over 100 incentivized choice tasks for each of more than 1,200 individuals.I jointly estimate population distributions of risk and time preferences complete with their individual-level stability and of people’s propensity to make mistakes. I am the first to do so using the Random Preference Model (RPM) which has been recently shown to have desirable theoretical properties over previously used frameworks. I show that the RPM has high internal validity. The five estimated structural parameters largely dominate a wide range of demographic and socio-economic variables when it comes to explaining observed individual choices between risky lotteries and time-separated payments.I demonstrate the economic and econometric significance of appending shocks directly to preferences and of incorporating the trembling hand parameter - their necessary complement in this framework. Mistakes and preference instability are not only separately identified but they are also linked to different cognitive and non-cognitive skills. I propose a Rationality Index which condenses them into a single indicator predictive of welfare loss.I use a factor model to extract cognitive ability and Big Five personality traits from noisy measures. They explain up to 50% of the variation in both average preferences and in individuals’ capacity to make consistent rational choices. Conscientiousness explains 45% and 10% respectively of the cross-sectional variation discount rates and risk aversion respectively as well as 20% of the variation in their individual-level stability. Furthermore, risk aversion is related to extraversion and mistakes are a function of cognitive ability, task design, and of effort. Preferences are stable for the median individual. Nevertheless, a part of the population exhibits some degree of preference instability consistent with imperfect self-knowledge.These results have implications both for specifying reduced form and structural economic models, and for explaining inequality and the inter-generational transmission of socioeconomic status
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Grau, Moya Jordi [Verfasser], e Daniel A. [Akademischer Betreuer] Braun. "Decision-Making under Bounded Rationality and Model Uncertainty : an Information-Theoretic Approach / Jordi Grau Moya ; Betreuer: Daniel A. Braun". Tübingen : Universitätsbibliothek Tübingen, 2017. http://d-nb.info/1165578204/34.
28
Chinsomboon, Garrett. "New model for the 5-20 cm wavelength opacity of ammonia pressure-broadened by methane under jovian conditions based on laboratory measurements". Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45858.
Abstract (sommario):
In order to fully understand the role methane (CH₄) plays in the microwave emission spectra of the deep atmospheres of the outer planets, over 280 laboratory measurements of the opacity of ammonia in a methane environment have been made in the 5-20 cm wavelength range. All opacity measurements were made with either 100 or 200 mbars of ammonia and with 1 to 3 bars of added methane in the 330-450K temperature range. A formalism for the absorptivity of ammonia broadened by methane has now been developed and had been applied to the Hanley et al. (Icarus, v. 202, 2009) model for the opacity of ammonia. Due to methane's relatively low abundance at Jupiter (~0.2% by volume), its effect on the microwave spectrum which will be observed by the Juno MWR (Microwave Radiometer) will be minimal. However, these experimental results will significantly improve the understanding of the microwave emission spectrum of Uranus and Neptune where methane plays a more dominant role.
29
Biggs, Timothy James. "Studies of crystalline organic molecular materials under extreme conditions". Thesis, University of Oxford, 2006. http://ora.ox.ac.uk/objects/uuid:51dae806-2954-4ea7-a3cb-1980ecb53e98.
Abstract (sommario):
This thesis describes investigations into the properties of -phase BEDT-TTF charge transfer salts. Charge transfer salts are mainly studied as they are very useful test beds for fundamental physics due to the tuneability of their proper- ties and ground states. The effects of temperature and pressure on such systems have been studied, as these allow access to a wide range of different states and properties. Transport properties of these systems have been studied to obtain information about the Fermi surface and effective mass, and the effect of deuter- ation and also change of pressure media will be discussed. The interaction of infrared radiation with these systems has also been investigated and simultaneous pressure and temperature measurements will be presented, something not greatly studied due to the large technical challenges. The techniques and approaches for overcoming these are also discussed. Chapter 1 provides an introduction to the organic materials themselves with particular emphasis on the actual compounds studied. Chapter 2 provides the necessary theoretical background for studying organic charge transfer salts using magnetic quantum oscillations and their infrared re- ectivity. Chapter 3 covers the experimental techniques and also discusses some of the challenges encountered and their solutions to aid others working in this area. Chapter 4 describes an investigation into the transport properties of - (ET)2Cu(SCN)2 by studying Shubnikov-de Haas oscillations using both deuter- ated and normal samples and using two different pressure media, and comparing it to work done using a third. Chapter 5 presents an investigation into the pressure dependence of selected phonon modes in -(ET)2Cu(SCN)2 using infrared radiation on a deuterated sam- ple. Chapter 6 presents what is believed to be the first pressure and temperature dependent infrared study of an organic molecular material. In this case the or- ganic molecular material is d8--(ET)2Cu[N(CN)2]Br, but the techniques should be readily transferable to other materials.
30
Li, Xiaogai. "Finite Element and Neuroimaging Techniques toImprove Decision-Making in Clinical Neuroscience". Doctoral thesis, KTH, Neuronik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-72345.
Abstract (sommario):
Our brain, perhaps the most sophisticated and mysterious part of the human body, to some extent, determines who we are. However, it’s a vulnerable organ. When subjected to an impact, such as a traffic accident or sport, it may lead to traumatic brain injury (TBI) which can have devastating effects for those who suffer the injury. Despite lots of efforts have been put into primary injury prevention, the number of TBIs is still on an unacceptable high level in a global perspective. Brain edema is a major neurological complication of moderate and severe TBI, which consists of an abnormal accumulation of fluid within the brain parenchyma. Clinically, local and minor edema may be treated conservatively only by observation, where the treatment of choice usually follows evidence-based practice. In the first study, the gravitational force is suggested to have a significant impact on the pressure of the edema zone in the brain tissue. Thus, the objective of the study was to investigate the significance of head position on edema at the posterior part of the brain using a Finite Element (FE) model. The model revealed that water content (WC) increment at the edema zone remained nearly identical for both supine and prone positions. However, the interstitial fluid pressure (IFP) inside the edema zone decreased around 15% by having the head in a prone position compared with a supine position. The decrease of IFP inside the edema zone by changing patient position from supine to prone has the potential to alleviate the damage to axonal fibers of the central nervous system. These observations suggest that considering the patient’s head position during intensive care and at rehabilitation should be of importance to the treatment of edematous regions in TBI patients. In TBI patients with diffuse brain edema, for most severe cases with refractory intracranial hypertension, decompressive craniotomy (DC) is performed as an ultimate therapy. However, a complete consensus on its effectiveness has not been achieved due to the high levels of severe disability and persistent vegetative state found in the patients treated with DC. DC allows expansion of the swollen brain outside the skull, thereby having the potential in reducing the Intracranial Pressure (ICP). However, the treatment causes stretching of the axons and may contribute to the unfavorable outcome of the patients. The second study aimed at quantifying the stretching and WC in the brain tissue due to the neurosurgical intervention to provide more insight into the effects upon such a treatment. A nonlinear registration method was used to quantify the strain. Our analysis showed a substantial increase of the strain level in the brain tissue close to the treated side of DC compared to before the treatment. Also, the WC was related to specific gravity (SG), which in turn was related to the Hounsfield unit (HU) value in the Computerized Tomography (CT) images by a photoelectric correction according to the chemical composition of the brain tissue. The overall WC of brain tissue presented a significant increase after the treatment compared to the condition seen before the treatment. It is suggested that a quantitative model, which characterizes the stretching and WC of the brain tissue both before as well as after DC, may clarify some of the potential problems with such a treatment. Diffusion Weighted (DW) Imaging technology provides a noninvasive way to extract axonal fiber tracts in the brain. The aim of the third study, as an extension to the second study was to assess and quantify the axonal deformation (i.e. stretching and shearing)at both the pre- and post-craniotomy periods in order to provide more insight into the mechanical effects on the axonal fibers due to DC. Subarachnoid injection of artificial cerebrospinal fluid (CSF) into the CSF system is widely used in neurological practice to gain information on CSF dynamics. Mathematical models are important for a better understanding of the underlying mechanisms. Despite the critical importance of the parameters for accurate modeling, there is a substantial variation in the poroelastic constants used in the literature due to the difficulties in determining material properties of brain tissue. In the fourth study, we developed a Finite Element (FE) model including the whole brain-CSF-skull system to study the CSF dynamics during constant-rate infusion. We investigated the capacity of the current model to predict the steady state of the mean ICP. For transient analysis, rather than accurately fit the infusion curve to the experimental data, we placed more emphasis on studying the influences of each of the poroelastic parameters due to the aforementioned inconsistency in the poroelastic constants for brain tissue. It was found that the value of the specific storage term S_epsilon is the dominant factor that influences the infusion curve, and the drained Young’s modulus E was identified as the dominant parameter second to S_epsilon. Based on the simulated infusion curves from the FE model, Artificial Neural Network (ANN) was used to find an optimized parameter set that best fit the experimental curve. The infusion curves from both the FE simulations and using ANN confirmed the limitation of linear poroelasticity in modeling the transient constant-rate infusion. To summarize, the work done in this thesis is to introduce FE Modeling and imaging technologiesincluding CT, DW imaging, and image registration method as a complementarytechnique for clinical diagnosis and treatment of TBI patients. Hopefully, the result mayto some extent improve the understanding of these clinical problems and improve theirmedical treatments.QC 20120201
31
Freitas, Taís Aparecida Vale. "O processo decisório frente à pressão do tempo: satisfação e variação dos estilos individuais de decisão". Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/12570.
Abstract (sommario):
The instigating pursuit to understand the human behavior, more precisely about the mechanisms involved in the decision-making process of a person, are the basic premise for the accomplishment of this study. Decisions are present in all ambits of people’s life, and the identification and understanding of the factors that can influence them have great importance. Thus, this study aimed to verify how individuals modify the decision process under time’s pressure. The reach of this objective occurred through a laboratory quasi-experiment using three different instruments to collect data. The first stage of the experiment was the choice of a notebook by using the decision support system Decisor (LÖBLER, 2005), the second stage consisted in answer the Feeling Questionnaire in Relation to the Purchase (LUCIAN, 2008) and the third one, answering the Decision Style Inventory (ROWE, 1998). The sample consisted in 178 undergraduate students, divided into 2 groups: the control group and the group submitted to time pressure. The most popular chosen notebook was Sony. It was observed the existence of prior knowledge of the brand and the use of Image Theory to explain that choice. The individual decision-making styles most found in the subjects submitted to the task were the analytical and the conceptual. The hypotheses were tested using the Mann Whitney U test and the chi-square test, however, they were unable to prove statistically the hypotheses. We suggest more studies to prove the existence of low satisfaction with choices made under time pressure.A instigante busca pela compreensão do comportamento humano, mais precisamente sobre os mecanismos envolvidos no processo decisório dos indivíduos, consistiu na premissa básica para a realização deste estudo. As decisões estão presentes em todos os âmbitos da vida dos indivíduos sendo de grande importância a identificação e compreensão dos fatores que podem influenciá-las. Assim, este estudo teve por objetivo verificar como os indivíduos modificam o processo decisório frente à pressão do tempo. O alcance desse objetivo ocorreu por meio de um quase experimento em laboratório utilizando três diferentes instrumentos de coleta de dados. A primeira etapa do quase experimento consistiu na escolha de um notebook utilizando o sistema de apoio à decisão Decisor (LÖBLER, 2005), a segunda etapa consistiu no preenchimento do Questionário de Sentimentos em Relação à Compra (LUCIAN, 2008) e a terceira no preenchimento do Decision Style Inventory (ROWE, 1998). A amostra foi composta por 178 alunos de graduação, divididos em 2 grupos: o grupo controle e o grupo submetido à pressão do tempo. O notebook mais escolhido pelos dois grupos foi o da marca Sony, observou-se a existência de conhecimento prévio da marca quanto à decisão de compra e também o uso da Teoria da Imagem para explicar a escolha. Os estilos individuais de decisão mais encontrados nos indivíduos submetidos à tarefa foram o analítico e o conceitual. As hipóteses foram testadas através do Teste U de Mann Whitney e do teste Qui-quadrado, contudo, as respostas obtidas nos testes não permitiram comprovar as três hipóteses estatisticamente. Sugere-se a realização de estudos mais aprofundados a fim de comprovar a existência de baixa satisfação com a escolha em decisões realizadas sob pressão do tempo.
32
Romanova, Mariya. "Theoretical study of the many-body electronic states of defects in diamond : the case of the NV center under high pressure". Thesis, Institut polytechnique de Paris, 2019. http://www.theses.fr/2019IPPAX013.
Abstract (sommario):
Ce travail de doctorat a pour objet l’étude, dans le diamant, de l'influence de la pression sur les transitions optiques entres l’état fondamental et les états excités du centre « azote-lacune de carbone » NV, sans paramètre ajustable. Le centre neutre NV0 et le centre chargé négativement NV- ont chacun été étudiés. L’étude a nécessité le développement d’un modèle de Hubbard où les valeurs des interactions sont obtenues sans ajustement sur l’expérience, par une méthode de calcul à partir des principes premiers.Le centre NV est un défaut à niveaux profonds, ses propriétés optiques et magnétiques sont liées aux niveaux sans dispersion dans la bande interdite électronique associés à des états électroniques fortement localisés. Ces niveaux proviennent de combinaisons linéaires d’orbitales localisées correspondant aux quatre liaisons pendantes pointant vers le centre de la lacune et issues des corrélations électroniques fortes. C'est pourquoi un traitement rigoureux, à l’échelle quantique, est nécessaire. La DFT est une approche puissante pour les calculs des propriétés de l'état fondamental des défauts ponctuels. Cependant, les états électroniques en DFT ont un caractère mono-déterminantal : un seul déterminant de Slater intervient, auquel il manque les corrélations non dynamiques. La DFT seule ne permet pas de calculer certains états électroniques à N - corps qui caractérisent les défauts profonds. De plus, les fonctionnelles d'échange et corrélation (FXC) utilisées en DFT ont une précision limitée.C'est pourquoi j’ai d’abord développé une approche combinée modèle d'Hubbard + DFT. La transition triplet-triplet entre l’état fondamental et le premier état triplet excité est étudié à la fois avec la FXC standard GGA-PBE, et la FXC hybride HSE06. Il est montré que l'utilisation de cette dernière améliore la description des corrélations au-delà de la DFT-PB, et permet la prédiction des transitions optiques plus précise. De plus, les interactions à longue portée ont un effet crucial dans la modélisation des défauts profonds: premièrement, les déformations élastiques, dues à la présence d’un atome de nature différente (N) de ceux de la matrice (C), sont à longue portée et doivent être prises en compte; ensuite, quand le défaut est chargé, il est important d'éviter l'interaction non-physique charge-charge entre supermailles voisines, causée par l'utilisation des conditions périodiques aux limites. Par conséquent, j’ai étudié la structure atomique d’un défaut dans de grandes supermailles.La diagonalisation exacte soit, en termes de chimie quantique, le calcul d'interaction de configurations, du Hamiltonian de Hubbard dans la base à plusieurs électrons, construite à partir des niveaux localisé dans la bande interdite, permet d’accéder aux états fondamental et excités multi-configurationels. Cette technique a été comparée aux méthodes récentes de l'état de l'art.La méthode développée est appliquée à l’étude de l'effet de la pression hydrostatique sur les niveaux triplets et singulets du centre NV-, et sur les niveaux doublets et quadruplets du centre NV0. Parmi les nombreux résultats, j'ai découvert un effet très intéressant lié à la transition singulet-singulet sous pression hydrostatique dans le centre NV-. Les résultats obtenus dans ce travail n'ont jamais été ni calculé ni mesurés expérimentalement. Pour valider mon modèle théorique, j'ai comparé mes résultats avec des mesures expérimentales disponibles pour les transitions optiques du centre NV- et du centre NV0 obtenus par nos collaborateurs. Enfin, l'effet de couplage électron-phonon a été discuté.En perspective, j'ai développé un nouveau code de calcul qui peut être utilisé pour étudier d'autres défauts d'interêt dans les technologies quantiquesThe aim of this thesis is to study the influence of the pressure on the optical transitions between multi-determinant ground state and excited states of the NV center from the first-principles.In this work, I study both the neutral NV0 and negatively charged NV- centers.Long-range interactions have a crucial effect in such defects: first, elastic deformations have a long range and need to be accounted for; second, when the defect has a charge, it is important to avoid spurious charge-charge interactions between neighboring supercells caused by the use of periodic boundary conditions. Thus, I study the atomic structure of defect with large supercells by the density functional theory (DFT).The NV center is a deep-center defect, its optical and magnetic properties are related with localized levels in the electronic band-gap. These levels are believed to be built out of the localized orbitals of dangling bonds pointing towards the vacancy, providing strongly correlated electronic states. Thus, an accurate quantum mechanical treatment is needed.DFT is a powerful approach for the calculation of the ground state properties of defects. However, the single Slater determinant nature of the DFT wave function lacks the non-dynamical correlations, that characterize such defects, and does not allow for the calculation of many-body levels. Moreover, exchange and correlation (XC) functionals used in DFT add have a limited accuracy.Therefore, in this PhD work, I first develop a combined DFT + Hubbard model technique. I study the triplet-triplet transition both with the PBE XC functional and the HSE06 one. I confirm that the use of the hybrid XC functional HSE06 improves the description of correlations beyond DFT-PBE and allows for more accurate prediction of optical transitions.An exact diagonalization (or in quantum chemistry language full Configuration Interaction calculations) of the Hubbard Hamiltonian in the many-electron basis constructed of in-gap localized levels, allows to get access to multi-determinant ground and excited states. I benchmark this technique comparing it to the recent state of the art methods.Finally, I apply the developed technique in order to study the effect of the hydrostatic pressure on NV- and NV0 centers. Among many results of my work, I discovered a very interesting effect related to the singlet-singlet transition in the NV-center under hydrostatic pressure. The results I have obtained during my PhD have never been calculated nor observed experimentally. In order to validate the theoretical model, I have compared our results with the measurements that have been obtained by our experimental collaborators for the optical transition in the NV- and NV0. Last but not least, the effect of the electron-phonon interaction was discussed.As a perspective, I developed a new code that can be applied to study other defect systems of interest in the quantum technologies
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Marques, Sérgio Filipe Veloso. "Comportamento de uma areia artificialmente cimentada até altas tensões de confinamento". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/148695.
Abstract (sommario):
A busca por novas soluções técnicas que, de modo sustentável, diminuam o tempo de construção de obras de engenharia e as tornem mais econômicas, tem tomado, cada vez mais, as linhas de pesquisa do grupo de Engenharia Geotécnica da Universidade Federal do Rio Grande do Sul, onde já foram realizadas inúmeras pesquisas para estudar e compreender o comportamento de solos artificialmente cimentados. O cimento Portland é mundialmente utilizado no melhoramento da resistência e da deformabilidade dos solos, outrora impróprios para utilização. Para estudar a contribuição da cimentação para altas tensões de confinamento, foi construído um equipamento triaxial com capacidade de atingir 10 MPa de tensão confinante que permite o estudo do comportamento tensão-deformação-dilatância de solos artificialmente cimentados curados sob tensão. Juntamente, foi realizado um estudo um numa areia fina e uniforme, artificialmente cimentada, para três tempos de cura (3, 7 e 28 dias), da resistência à compressão simples (qu) e da resistência à compressão diametral (qt) em função da razão vazios/cimento (η/Civ). Os resultados mostraram que a resistência aumenta com a redução da relação vazios/cimento (η/Civ) e com o aumento do tempo de cura (t), sendo que a relação tração/compressão (qt/qu) é independente do tempo de cura e apresenta um valor médio de 0,15. Além dos resultados proferidos, outras misturas de solos granulares com diferentes tipos de cimento, variados tempos de cura, foram analisados e normalizados, obtendo-se uma curva única em que a resistência à compressão simples (qu) e a resistência à compressão diametral (qt) foram normalizadas e estão em função da relação vazios/cimento (η/Civ). Paralelamente pretendeu-se verificar qual o efeito do tipo de cura (sob tensão ou atmosférica) em misturas cimentadas com a realização de ensaios para tensões efetivas médias desde 250 kPa até 4000 kPa. Além disso, avaliou-se a variação do η/Civ e do tempo de cura para amostras curadas sob tensão. Os resultados mostram que, de um modo geral, com o aumento da tensão efetiva média, o tipo de cura não afeta os valores das tensões de desvio máximas. A parcela friccional tem uma predominância no comportamento tensão-deformação. O tipo de cura tem influência na definição da superfície de plastificação e da rigidez, verificando-se o aumento destas propriedades para amostras curadas sob tensão em relação a amostras curadas sob pressão atmosférica. Com base nos resultados obtidos nesta pesquisa, um modelo elasto-plástico com degradação da rigidez, que tem como parâmetros a resistência a compressão simples (qu), ângulo de atrito (ϕ’) e uma deformação equivalente (εs 0,7), foi proposto para simular o comportamento tensão-deformação de misturas de areias artificialmente cimentados em ensaios triaxiais, apresentando resultados satisfatórios.The search for new technical solutions to reduce construction time of engineering works and to make them more cost-effective has been object of the research lines of the group of Geotechnical Engineering of Federal University do Rio Grande do Sul. Numerous studies have been conducted to analyse and understand the behaviour of artificially cemented. Portland cement is widely used for improving strength and deformability characteristics of soils. To study the contribution of cementation under high pressures, a 10 MPa confining pressure triaxial apparatus was built to study the stress-strain-dilatancy behaviour of artificially cemented soils cured under stress. In parallel a study was conducted on a artificially cemented uniform sand at three curing times (3, 7 and 28 days) to determine the unconfined compressive strength (qu) and splitting tensile strength (qt) according to voids/cement ratio (η/Civ) dosage methodology. The results showed that strength increases with the reduction of voids/cement ratio (η/Civ) and with the increasing of cure time (t). The tensile/compression ratio (qt/qu) is independent of curing time and presents a mean value of 0.15. In addition to these results, other granular soils mixtures with distinct types of cement and different curing times were analysed. A unique normalized curve was fit to unconfined compressive strength (qu) and splitting tensile strength (qt) against voids/cement ratio (η/Civ). At the same time, the effect of the curing type (under stress or atmospheric) was verified through triaxial compression tests with mean effective stresses ranging from 250 kPa to 4000 kPa. In addition, the variation of η/Civ and cure time was evaluated for samples cured under stress. The results show that, in general, by increasing the mean effective stress, the type of cure does not affect the values of the maximum deviatoric stress. The frictional portion is predominant in the stress-strain behavior. The type of cure affects the yielding surface and the stiffness of the samples. It was observed the increase in this properties for samples cured under stress compared to samples cured with atmospheric stress. Based on the outcomes of this study, with satisfactory results, an elastoplastic model with stiffness degradation (using unconfined compressive strength (qu), friction angle (’) and an equivalent strain ( s0.7)) was proposed to simulate the stress-strain behaviour of artificially cemented sands in triaxial tests.
34
Kowalczyk, Piotr Jozef. "Validation and application of advanced soil constitutive models in numerical modelling of soil and soil-structure interaction under seismic loading". Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/275675.
Abstract (sommario):
This thesis presents validation and application of advanced soil constitutive models in cases of seismic loading conditions.
Firstly, results of three advanced soil constitutive models are compared with examples of shear stack experimental data for free field response in dry sand for shear and compression wave propagation. Higher harmonic generation in acceleration records, observed in experimental works, is shown to be possibly the result of soil nonlinearity and fast elastic unloading waves. This finding is shown to have high importance on structural response, real earthquake records and reliability of conventionally employed numerical tools. Finally, short study of free field response in saturated soil reveals similar findings on higher harmonic generation.
Secondly, two advanced soil constitutive models are used, and their performance is assessed based on examples of experimental data on piles in dry sand in order to validate the ability of the constitutive models to simulate seismic soil-structure interaction. The validation includes various experimental configurations and input motions. The discussion on the results focuses on constitutive and numerical modelling aspects. Some improvements in the formulations of the models are suggested based on the detailed investigation.
Finally, the application of one of the advanced soil constitutive models is shown in regard to temporary natural frequency wandering observed in structures subjected to earthquakes. Results show that pore pressure generated during seismic events causes changes in soil stiffness, thus affecting the natural frequency of the structure during and just after the seismic event. Parametric studies present how soil permeability, soil density, input motion or a type of structure may affect the structural natural frequency and time for its return to the initial value. In addition, a time history with an aftershock is analysed to investigate the difference in structural response during the earthquake and the aftershock.
35
Kowalczyk, Piotr Jozef. "Validation and application of advanced soil constitutive models in numerical modelling of soil and soil-structure interaction under seismic loading". Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/275675.
Abstract (sommario):
This thesis presents validation and application of advanced soil constitutive models in cases of seismic loading conditions.
Firstly, results of three advanced soil constitutive models are compared with examples of shear stack experimental data for free field response in dry sand for shear and compression wave propagation. Higher harmonic generation in acceleration records, observed in experimental works, is shown to be possibly the result of soil nonlinearity and fast elastic unloading waves. This finding is shown to have high importance on structural response, real earthquake records and reliability of conventionally employed numerical tools. Finally, short study of free field response in saturated soil reveals similar findings on higher harmonic generation.
Secondly, two advanced soil constitutive models are used, and their performance is assessed based on examples of experimental data on piles in dry sand in order to validate the ability of the constitutive models to simulate seismic soil-structure interaction. The validation includes various experimental configurations and input motions. The discussion on the results focuses on constitutive and numerical modelling aspects. Some improvements in the formulations of the models are suggested based on the detailed investigation.
Finally, the application of one of the advanced soil constitutive models is shown in regard to temporary natural frequency wandering observed in structures subjected to earthquakes. Results show that pore pressure generated during seismic events causes changes in soil stiffness, thus affecting the natural frequency of the structure during and just after the seismic event. Parametric studies present how soil permeability, soil density, input motion or a type of structure may affect the structural natural frequency and time for its return to the initial value. In addition, a time history with an aftershock is analysed to investigate the difference in structural response during the earthquake and the aftershock.
36
Savage, David A. "Economics of maritime disasters : essays on the Titanic and Lusitania". Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/35730/1/David_Savage_Thesis.pdf.
Abstract (sommario):
This work seeks to fill some of the gap existing in the economics and behavioural economics literature pertaining to the decision making process of individuals under extreme environmental situations (life and death events). These essays specifically examine the sinking’s of the R.M.S. Titanic, on 14th April of 1912, and the R.M.S. Lusitania, on 7th May 1915, using econometric (multivariate) analysis techniques. The results show that even under extreme life and death conditions, social norms matter and are reflected in the survival probabilities of individuals onboard the Titanic. However, results from the comparative analysis of the Titanic and Lusitania show that social norms take time to organise and be effective. In the presence of such time constraints, the traditional “homo economicus” model of individual behaviour becomes evident as a survival of the fittest competition.
37
Oesterle, Jonathan. "Holistic approach to designing hybrid assembly lines A comparative study of Multi-Objective Algorithms for the Assembly Line Balancing and Equipment Selection Problem under consideration of Product Design Alternatives Evaluation of the influence of dominance rules for the assembly line design problem under consideration of product design alternatives Hybrid Multi-objective Optimization Method for Solving Simultaneously the line Balancing, Equipment and Buffer Sizing Problems for Hybrid Assembly Systems Comparison of Multiobjective Algorithms for the Assembly Line Balancing Design Problem Efficient multi-objective optimization method for the mixed-model-line assembly line design problem Detaillierungsgrad von Simulationsmodellen Rechnergestützte Austaktung einer Mixed-Model Line. Der Weg zur optimalen Austaktung". Thesis, Troyes, 2017. http://www.theses.fr/2017TROY0012.
Abstract (sommario):
Le travail présenté dans cette thèse concerne la formulation et la résolution de deux problèmes d'optimisation multi-objectifs. Ces problèmes de décision, liés à une approche holistique, ont pour but de sélectionner la meilleure configuration « produit/ligne d’assemblage » à partir d'un ensemble de design produits, et de ressources. Concernant le premier problème, un modèle de coût a été développé afin de traduire les interdépendances complexes entre la sélection d’un design produit et les caractéristiques des ressources. Une étude empirique est proposée et vise à comparer, selon plusieurs indicateurs de qualité multi-objectifs, différentes méthodes de résolution - comprenant des algorithmes génétiques, de colonies de fourmis, d’optimisation par essaims particulaires, des chauves-souris, de recherche du coucou et de pollinisation des fleurs. Plusieurs règles de dominance et une recherche locale spécifique au problème ont été appliquées aux méthodes de résolution les plus prometteuses. Concernant le second problème, qui se penche également sur le dimensionnement des stocks tampons, les méthodes de résolution sont à un modèle de simulation à événements discrets, dont la fonction première est l’évaluation des valeurs des différentes fonctions objectives. L’approche holistique associée aux deux problèmes a été validée avec deux cas industrielsThe work presented in this thesis concerns the formulation and the resolution of two holistic multi-objective optimization problems associated with the selection of the best product and hybrid assembly line configuration out of a set of products, processes and resources alternatives. Regarding the first problem, a cost model was developed in order to translate the complex interdependencies between the selection of specific product designs, processes and resources characteristics. An empirical study is proposed, which aimed at comparing, according to several multi-objective quality indicators, various resolution methods – including variants of evolutionary algorithms, ant colony optimization, particle swarm optimization, bat algorithms, cuckoo search algorithms, and flower-pollination algorithms. Several dominance rules and a problem-specific local search were applied to the most promising resolution methods. Regarding the second problem, which also considers the buffer sizing, the developed algorithms were enhanced with a genetic discrete-event simulation model, whose primary function is to evaluate the value of the various objective functions. The demonstration of the associated resolution frameworks for both problems was validated through two industrial-cases
38
Amawatana, Chonchinee. "Environmental performance indicators for the lower Mekong subregion development". Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/16684/1/Chonchinee_Amawatana_Thesis.pdf.
Abstract (sommario):
The application of environmental performance indicators (EPIs) has received increasing attention by both governments and international organisations as a tool for assessing complex environmental scenarios in national and local decision making processes. However, at the regional scale there is a gap in the application of EPIs, as this has not been well understood and defined due to a limited theoretical foundation and often insufficient data from all participant countries. The regional scale is important because it can incorporate natural ecosystems which often transcend national boundaries. A case study is developed for the Lower Mekong Subregion (LMS), where four riparian Southeast Asian countries (Lao PDR, Thailand, Cambodia, and Viet Nam) share the Lower Mekong River.
The research proposes a conceptual framework to identify approaches for developing criteria for acceptable and appropriate EPIs which can be used to support and implement decision making processes by relevant organisations at the regional level. This research evaluates the application of environmental performance indicators using methodologies that assess cross-national quantitative and qualitative data and existing decision support systems. In addition, global and national indicators are examined for application and relation to the regional context.
The research finds that the application of EPIs varies according to spatial scale, and is diverse among the four countries. Data availability is also identified as a major problem encountered during the development and selection of EPIs. The study finds that the governance of the existing regional body is ineffective due to differing agendas pursued by each participating country. This is because the current regional body is structured only to facilitate information exchange and cooperation in a limited manner, focusing so far only on water management issues. LMS regional goals need to be set in order to guide the stakeholders in identifying an appropriate set of EPIs. Most importantly, the research is intended to be a catalyst for encouraging the participants to integrate methods and other species of EPIs proposed in this research in their environmental assessment policies.
39
Amawatana, Chonchinee. "Environmental performance indicators for the lower Mekong subregion development". Queensland University of Technology, 2008. http://eprints.qut.edu.au/16684/.
Abstract (sommario):
The application of environmental performance indicators (EPIs) has received increasing attention by both governments and international organisations as a tool for assessing complex environmental scenarios in national and local decision making processes. However, at the regional scale there is a gap in the application of EPIs, as this has not been well understood and defined due to a limited theoretical foundation and often insufficient data from all participant countries. The regional scale is important because it can incorporate natural ecosystems which often transcend national boundaries. A case study is developed for the Lower Mekong Subregion (LMS), where four riparian Southeast Asian countries (Lao PDR, Thailand, Cambodia, and Viet Nam) share the Lower Mekong River. The research proposes a conceptual framework to identify approaches for developing criteria for acceptable and appropriate EPIs which can be used to support and implement decision making processes by relevant organisations at the regional level. This research evaluates the application of environmental performance indicators using methodologies that assess cross-national quantitative and qualitative data and existing decision support systems. In addition, global and national indicators are examined for application and relation to the regional context. The research finds that the application of EPIs varies according to spatial scale, and is diverse among the four countries. Data availability is also identified as a major problem encountered during the development and selection of EPIs. The study finds that the governance of the existing regional body is ineffective due to differing agendas pursued by each participating country. This is because the current regional body is structured only to facilitate information exchange and cooperation in a limited manner, focusing so far only on water management issues. LMS regional goals need to be set in order to guide the stakeholders in identifying an appropriate set of EPIs. Most importantly, the research is intended to be a catalyst for encouraging the participants to integrate methods and other species of EPIs proposed in this research in their environmental assessment policies.
40
Vilchis, Medina José Luis. "Modeling of resilient systems in non-monotonic logic : application to solar power UAV". Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0567/document.
Abstract (sommario):
Cette thèse présente un modèle résilient pour piloter un avion basé sur une logique non monotone. Ce modèle est capable de gérer des solutions à partir d’informations incomplètes, contradictoires et des exceptions. C’est un problème très connu en Intelligence Artificial, qui est étudié depuis plus de 40 ans. Pour ce faire, nous utilisons la logique des défauts pour formaliser la situation et trouver des conclusions possibles. Grâce à cette logique, nous pouvons transformer les règles de pilotage en défauts. Ensuite, lorsque nous calculons les solutions, plusieurs options peuvent en résulter. À ce stade, il existe un critère de décision opportuniste pour choisir la meilleure solution. Le contrôle du système se fait via la propriété de résilience. Nous redéfinissons cette propriété comme l’intégration de la logique non monotone dans le modèle de Minsky. En conséquence, il est démontré que le modèle de résilience proposé pourrait être généralisé aux systèmes intégrant une connaissance du monde contenant des situations, des objectifs et des actions. Enfin, nous présentons les résultats expérimentaux et la conclusion de la thèse en discutant des perspectives et des défis pour les orientations futures. Différentes applications dans d’autres domaines sont prises en compte pour l’intérêt du comportement du modèleThis thesis presents a resilient model to pilot an aircraft based on a non-monotonic logic. This model is capable of handling solutions from incomplete, contradictory information and exceptions. This is a very well known problem in Artificial Intelligence, which has been studied for more than 40 years. To do this, we use default logic to formalise the situation and find possible conclusions. Thanks to this logic we can transform the piloting rules to defaults. Then, when we calculate the solutions, several options could result. At this point an opportunistic decision criteria takes place to choose the better solution. The control of the system is done via the property of resilence, we redefine this property as the integration of the non-monotonic logic in the Minsky’s model. As a result, it is shown that the proposed resilient model could be generalised to systems that incorporate a knowledge of the world that contains situations, objectives and actions. Finally, we present the experimental results and conclusion of the thesis discussing the prospects and challenges that exist for future directions. Different applications in other fields are taken into account for the interest of the model’s behavior
41
Gai, Guodong. "Modeling of water sprays effects on premixed hydrogen-air explosion, turbulence and shock waves Modeling pressure loads during a premixed hydrogen combustion in the presence of water spray Numerical study on laminar flame velocity of hydrogen-air combustion under water spray effects Modeling of particle cloud dispersion in compressible gas flows with shock waves A new formulation of a spray dispersion model for particle/droplet-laden flows subjected to shock waves Particles-induced turbulence: a critical review of physical concepts, numerical modelings and experimental investigation A new methodology for modeling turbulence induced 1 by a particle-laden flow using a mechanistic model". Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR14.
Abstract (sommario):
Cette thèse de doctorat est dédiée au développement de modèles physiques pour l’étude des systèmes d’aspersion de gouttelettes d’eau en milieu réactif d’hydrogène-air pré-mélangée dans les centrales nucléaires. Des modèles d’ordre réduit sont développés pour décrire l’évaporation des gouttelettes d’eau dans la flamme, la dispersion des nuages de particules après le passage des ondes de choc et l’évolution de l’échelle caractéristiques de turbulence avec la présence d’un jet d’eau. Une nouvelle méthodologie est proposée pour évaluer les effets de l’évaporation par l’aspersion sur la propagation de la flamme d’hydrogène turbulente à l’intérieur d’un volume fermé et un modèle simple est développé pour la quantification de la décélération de la vitesse laminaire avec l’évaporation des gouttelettes à l’intérieur de la flamme. Également, un modèle analytique est proposé pour la prédiction de la dispersion de nuage de particule après le passage d’une onde de choc en s’appuyant sur le one-way formalisme avec une extension afin de prédire l’apparition d’un pic de densité du nombre de particules en utilisant le two-way formalisme. En ce qui concerne la modulation de la turbulence induite par les particules, un modèle simple est utilisé pour l’estimation des échelles intégrales de la turbulence induites par l’injection de nuage des particules. Ces modèles numériques développés peuvent être couplés pour être mis en œuvre dans les simulations numériques à grande échelle de l’effet du système d’aspersion sur les explosions accidentelles d’hydrogène dans les centrales nucléairesThis PhD dissertation is dedicated to develop simple models to investigate the effect of water spray system on the premixed hydrogen-air combustion in the nuclear power plants. Specific simple models are developed to describe the water droplet evaporation in the flame, particle cloud dispersion after the shock wave passage, and turbulence length scale evolution with the presence of a water spray. A methodology is proposed to evaluate the spray evaporation effects on the propagation of the turbulent hydrogen flame inside a closed volume and a simple model is developed for the quantification of the laminar velocity deceleration with the droplets evaporation inside the flame. An analytical model is proposed for the prediction of particle cloud dispersion after the shock passage in the one-way formalism and another analytical model is dedicated to describe the spray-shock interaction mechanism and predict the appearance of a particle number density peak using the two-way formalism. A review of the important criteria and physical modelings related to the particle-induced turbulence modulation is given and a mechanistic model is used for the estimation of the turbulent integral length scales induced by the injection of particle clouds. These developed numerical models can be coupled to implement in the large-scale numerical simulations of the spray system effects on the accidental hydrogen explosions in the nuclear power plants
42
Vilchis, Medina José Luis. "Modeling of resilient systems in non-monotonic logic : application to solar power UAV". Electronic Thesis or Diss., Aix-Marseille, 2018. http://theses.univ-amu.fr.lama.univ-amu.fr/181212_VILCHISMEDINA_706br796xrxee121bcfd495dmdd_TH.pdf.
Abstract (sommario):
Cette thèse présente un modèle résilient pour piloter un avion basé sur une logique non monotone. Ce modèle est capable de gérer des solutions à partir d’informations incomplètes, contradictoires et des exceptions. C’est un problème très connu en Intelligence Artificial, qui est étudié depuis plus de 40 ans. Pour ce faire, nous utilisons la logique des défauts pour formaliser la situation et trouver des conclusions possibles. Grâce à cette logique, nous pouvons transformer les règles de pilotage en défauts. Ensuite, lorsque nous calculons les solutions, plusieurs options peuvent en résulter. À ce stade, il existe un critère de décision opportuniste pour choisir la meilleure solution. Le contrôle du système se fait via la propriété de résilience. Nous redéfinissons cette propriété comme l’intégration de la logique non monotone dans le modèle de Minsky. En conséquence, il est démontré que le modèle de résilience proposé pourrait être généralisé aux systèmes intégrant une connaissance du monde contenant des situations, des objectifs et des actions. Enfin, nous présentons les résultats expérimentaux et la conclusion de la thèse en discutant des perspectives et des défis pour les orientations futures. Différentes applications dans d’autres domaines sont prises en compte pour l’intérêt du comportement du modèleThis thesis presents a resilient model to pilot an aircraft based on a non-monotonic logic. This model is capable of handling solutions from incomplete, contradictory information and exceptions. This is a very well known problem in Artificial Intelligence, which has been studied for more than 40 years. To do this, we use default logic to formalise the situation and find possible conclusions. Thanks to this logic we can transform the piloting rules to defaults. Then, when we calculate the solutions, several options could result. At this point an opportunistic decision criteria takes place to choose the better solution. The control of the system is done via the property of resilence, we redefine this property as the integration of the non-monotonic logic in the Minsky’s model. As a result, it is shown that the proposed resilient model could be generalised to systems that incorporate a knowledge of the world that contains situations, objectives and actions. Finally, we present the experimental results and conclusion of the thesis discussing the prospects and challenges that exist for future directions. Different applications in other fields are taken into account for the interest of the model’s behavior
43
LUINI, LORENZO PAOLO. "Deciding Under Pressure". Doctoral thesis, 2012. http://hdl.handle.net/11573/917182.
Abstract (sommario):
Cognitive psychology research focused on the relationship between automatic and controlled cognition referring to split-second decisions (Payne, 2001, 2006) and examined the effect that race as an ethnic group factor leads to a response bias in shooting decisions using videogame-like tasks (Correll, Park, Judd, & Wittenbrink, 2002; Correll et al., 2007). A weapon bias was reported in judgement denoted as a perceptual weapon-tool classification (Payne, 2001, 2006) and as a behavioural shoot-do not shoot decision (Correll, Park, Judd, & Wittenbrink, 2002; Correll et al., 2007; Greenwald, Oakes, & Hoffman, 2003). The aim of this research was to investigate the impact of arousal, valence and content of IAPS pictures on measures of perceptive sensitivity (d’), response bias (c) and reaction times (RTs). Two Weapon Identification Tasks (WIT) and two First Person Shooting Tasks (FPST) were performed manipulating emotional and arousing contents of visual stimuli. Findings are consistent with the hypothesis that affective modulation influences response bias activation and performance, and that content of stimuli amplifies the effect size.
44
Lin, Dyi-Yih, e 林迪意. "Decision Training for Human Rule-Based Reasoning under Time Pressure". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/66325927596114972189.
Abstract (sommario):
博士國立交通大學
工業工程與管理學系
85
In many emergency situations, human operators need to derive countermeasures based on contingency rules whilst under time pressure. Since it has been found that people tend to process information intuitively and to be overconfident regarding their performance level, it is necessary that operators be well trained in decision making for the safety-related domain. In order to contribute to the human success in playing such a role, the present study intends to examine the effectiveness of using expert systems, an excellent rule-based reasoner, to train for the desired decision performance. Emergency management of chemical spills was selected to exemplify the rule-based decision task. An expert system in this domain was developed to serve as the training tool. Forty subjects participated in an experiment in which a computerized information board was used to capture subjects'' rule-based performance under the manipulation of time pressure and training The experiment results indicate that people adapt to time pressure by accelerating their processing of rules where the heuristic of cognitive availability was employed. The simplifying strategy was found to be the source of human error in rule-based reasoning, and also the root resulting in confirmation bias that led to overconfidence. The results also show that the decision behavior of individuals who undergo the expert system training is directed to a normative and expeditious pattern, which leads to an improved level of decision accuracy and appropriate realism of confidence judgment. Implications of these findings for human decision behavior, computer-aided training, interface design, and industrial safety are examined in the present study.
45
Liu, Chi-Pei, e 劉季蓓. "The bid price decision model under market competition". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/00048994131620374237.
Abstract (sommario):
碩士國立高雄第一科技大學
營建工程所
91
In a recession of the construction market, there are reduced work opportunities for contractors. Confronted with the austerity in the business environment, contractors would cut their bid prices to compete for a job with contract winning as a high priority. However, a price-cutting decision in the face of loss risk to get a job should not be made like gambling with results depending entirely on luck, but rather a rational choice made after careful calculations. The existing bidding models can be categorized as the probability-based model, the utility theory model, or the present worth model. The probability-based model produces a recommended optimal markup based on maximum expected profit, but the problem of the model is that in intense competition the chance of being low bid with such a markup is too low. The utility theory model produces a recommended markup based on the utility value of the job being tendered and the relation between job utility and markup from experience. The present worth model is based on cash flows analysis and required minimum rate of return without regard to how competitive a bid thus suggested will be. All these three types are non-survival-oriented models. The objective of this research is to develop an improved bidding model more suitable for use in intense competition while guiding contractors through a bid decision without taking unnecessary financial risk. Based on a study in the literature of the factors influencing bid decisions, three criteria are included in the proposed bidding model: the probability of winning, the probability of making a loss, and the need for the job. For varying bid prices being considered for a job, the estimated probabilities of winning are calculated using an existing model from historical data, whereas the probabilities of making a loss are evaluated with the probability distribution of project cost. The obtained probabilities are used along with the need for the job as inputs to a fuzzy logic system that incorporates the priorities of the decision maker in the three criteria for producing a score for each possible bid amount. The amount with the highest score is the recommended bid price. A case study involving a highway construction project is used in this research to illustrate the model. The contractor’s possible attitudes to risk, i.e. risk-taking, risk-neutral, and risk-averse, are simulated by three sets of fuzzy rules for a comparison of their effects. The results show that the model is sensitive enough to recommend bid prices in accordance with the differences in risk attitudes, thereby addressing one shortcoming of the existing models.
46
Chou, Pai-Ying, e 周百瑩. "A Bank Asset-Liability Model under Fuzzy Decision". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/58647656394686241336.
47
Yeh, Su-Fang, e 葉書芳. "The Consumer Preference Analysis under Multiattribute Decision Making Model". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/17818986168446837272.
Abstract (sommario):
碩士國立臺灣大學
國際企業學研究所
93
Generally when consumers buy a product, their decision model is one kind of multiple attribute decision making model. Moreover, conjoint analysis is the most popular analysis method applied in consumer preference research under multiple attribute decision making model. However, conjoint analysis has some limits. When there are a large number of product attributes or levels within attributes, it is difficult for respondent to evalluate the stimulus, which influence the difficulty of data collection and accuracy of analysis. Base on consumer behavior theory, each consumer has different perception. Therefore, different consumer has different involvement which lead the difference of decision making. This study is intended to combine involvement concept with conjoint analysis to explore whether involvement can explain the consumer behavior under multiple attribute decision making model and whether there are preference difference between consumers having different involvement. In this study notebook and instant noodles are used to be the research products. The empirical results show: 1.There are some significant differences in preference and attributes between low-involvement and high-involvement consumers. The most important attribute for high-involvement notebook consumer is price but for low-involvement notebook consumer is brand; the most important attribute for high-involvement instant noodles consumer is flavor but for low-involvement instant noodles consumer is enclosed condiment. 2.There are some significant differences in the number of considerated attributes between low-involvement and high-involvement consumers. Generally speaking, the number of attributes that high-involvement consumer consider with is more than he number of attributes that low-involvement consumer consider with.
48
Yung-chang, Huang, e 黃永昌. "The Model of Local Competition Pressure under Fewer Children Impact". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/31499980590881918301.
Abstract (sommario):
碩士育達科技大學
資訊管理所
103
The tendency of fewer children impacts the development of Taiwan’s education because the structure of population has been changed in Taiwan. Thus, the investigation of the phenomenon of fewer children has its urgent conditions and its important significance. This study mainly tries to discuss the affections of fewer children for local junior high and elementary schools, and investigates the influences for operating schools under the competition pressures. In addition, this work tries to find out that the disbursement policy would provide the characteristics and images of school to cope with the competition under the tendency of fewer children. Such a phenomenon would discuss through the simulation behaviors. Actually, the simulated results could provide some concrete suggestions for a school under the local competition pressures. The relevant variables of operating schools are complicate, especially in discussing the local competition pressures. In social sciences, the investigations of operating schools under competition pressure always adopt the static qualitative approach, but lacking the dynamic discussions. However, the dynamic discussions are more nearly practice. Based upon this, this paper is to construct a systems dynamic model to explore the complicate influences of operating school under the tendency of fewer children and the pressure of local competitions. Most studies of school operations are limited in static investigations, but this work is going to conduct dynamic discussions through the development of system dynamic model. The systems dynamic model not only improves the study from static level to dynamic level, but makes the discussing topics more practice. Simulated results reveal that more equipment cost input won’t make the amount of students increase linearly, it would be the referenced suggestion while policy making. In addition, the percentage policy of budget balance would adopt staged policy, the higher policy is applied in the front stage and the lower policy is adopted in the rest stage. Moreover, the higher marketing percentage policy is applied through the whole simulated period because the higher marketing percentage would result the more amount of students and the stronger competitiveness. In summary, this study can be regarded as a valuable tool because it can easily duplicate to solve other cases by changing its input parameters only. Keyword: tendency of fewer children, systems dynamic, competition pressure
49
Chen, Ying-Chih, e 陳英治. "Research on the Decision Making Behavior of Human Factors under Different Pressure Situations". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7q8e26.
Abstract (sommario):
碩士國立臺北科技大學
土木工程系土木與防災碩士班
105
The current domestic regulations and evacuation verification only consider the shortest-way principles to choose escape exports, making the simulation results too optimistic and ideal. When in the fire place, you have option to choose another exports when you face crowded exports. In other words, in the case of other escape exports, people have opportunity to change the route when they face stuck exports. However, in the past, simulations and researches both ignored this phenomenon. Therefore, this study hopes to explore the decision-making mode, when people face a stuck export in the fire place, and the total impacts of evacuation. This research, first, investigates the decision-making behavior of people facing blocked exports, and calculates ratios in each different situations. Furthermore, this research analysis decision trees between different pressure and every human factors, and discuss relationships between them. This study hopes to provide basis for fire place simulations and recommendations of evacuation design and planning in the future. ii According to the above experiments and data analysis, the conclusion is that even if the situation II, which is that in the first floor and no fire source, is closest to the simulation of the escape software, 70.85% of the people facing blocked exports will change to another export. This is different from the previous studies.
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Lin, Ro-Sen, e 林若森. "Project risk decision model under risk preference and limited resources". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/70334134153652023262.
Abstract (sommario):
碩士國立臺灣大學
工業工程學研究所
95
During the execution of a project, unexpected events usually cause delay and financial loss, these are termed project risks. As a result, in order to reduce the impact of project risk, effective risk management model becomes an important issue. This study integrates project risk analysis models proposed by scholars and introduces the concept of risk preference to establish a project risk decision model. Decision makers can evaluate each risk treatment strategy according to their own risk preference. This study establishes a project risk decision model and uses “risk decrease” to replace “effect” as the evaluating index. Furthermore, the utility based-selection decision support problem model (u-sDSP) is employed to evaluate the utility of risk treatment strategies for decision makers. Finally, the principle of integer programming is adopted to determine the optimal set of risk treatment strategies which maximizes effects with limited resources. Taking a case of Torpedo Development Project as an example, the proposed combined model is employed in the analysis, and the result is compared with those obtained form other models. In conclusion, results obtained from the proposed model of this study is better. The reason is attributed to that the project risk decision model established by this study has taken risk preference into consideration. Thus, in practical application, the proposed model can provide better decision making solutions for decision makers.