Bibliografie tematiche / Critical scenarios

Letteratura scientifica selezionata sul tema "Critical scenarios"

Autore: Grafiati

Pubblicato: 8 giugno 2024

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Articoli di riviste sul tema "Critical scenarios":

Höhne, Gordon, Michael Fuhrmann e Robert Luckner. "Critical wake vortex encounter scenarios". Aerospace Science and Technology 8, n. 8 (dicembre 2004): 689–701. http://dx.doi.org/10.1016/j.ast.2004.07.005.

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Weber, James. "Scenarios in Business Ethics Research: Review, Critical Assessment, and Recommendations". Business Ethics Quarterly 2, n. 2 (aprile 1992): 137–60. http://dx.doi.org/10.2307/3857568.

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A growing number of researchers in the business ethics field have used scenarios as a data gathering technique in their empirical investigations of ethical issues. This paper offers a review and critique of 26 studies that have utilized scenarios to elicit inferences of ethical reasoning, decision making, and/or intended behavior from managerial or student populations. The use of a theoretical foundation, the development of hypotheses, various characteristics germane to the use of scenarios, population and sampling issues, and the use of statistical measures are explored and assessed. In the interest of improving scenario-based research, ten recommendations are presented to guide future scenario research.

Batsch, Felix, Alireza Daneshkhah, Vasile Palade e Madeline Cheah. "Scenario Optimisation and Sensitivity Analysis for Safe Automated Driving Using Gaussian Processes". Applied Sciences 11, n. 2 (15 gennaio 2021): 775. http://dx.doi.org/10.3390/app11020775.

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Assuring the safety of automated vehicles is essential for their timely introduction and acceptance by policymakers and the public. To assess their safe design and robust decision making in response to all possible scenarios, new methods that use a scenario-based testing approach are needed, as testing on public roads in normal traffic would require driving millions of kilometres. We make use of the scenario-based testing approach and propose a method to model simulated scenarios using Gaussian Process based models to predict untested scenario outcomes. This enables us to efficiently determine the performance boundary, where the safe and unsafe scenarios can be evidently distinguished from each other. We present an iterative method that optimises the parameter space of a logical scenario towards the most critical scenarios on this performance boundary. Additionally, we conduct a novel probabilistic sensitivity analysis by efficiently computing several variance-based sensitivity indices using the Gaussian Process models and evaluate the relative importance of the scenario input parameters on the scenario outcome. We critically evaluate and investigate the usefulness of the proposed Gaussian Process based approach as a very efficient surrogate model, which can model the logical scenarios effectively in the presence of uncertainty. The proposed approach is applied on an exemplary logical scenario and shows viability in finding concrete critical scenarios. The reported results, derived from the proposed approach, could pave the way to more efficient testing of automated vehicles and instruct further physical tests on the determined critical scenarios.

Nazarko, Joanicjusz, e Anna Kononiuk. "THE CRITICAL ANALYSIS OF SCENARIO CONSTRUCTION IN THE POLISH FORESIGHT INITIATIVES". Technological and Economic Development of Economy 19, n. 3 (3 ottobre 2013): 510–32. http://dx.doi.org/10.3846/20294913.2013.809030.

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The aim of the article is to present the diagnosis of scenario method application in the Polish foresight initiatives. The concept of scenario method, its evolution, the state of the art of the Polish foresight studies and the critical analysis of the application of this method have been presented. From the questionnaire results the authors have identified (i) the approach used in scenario construction, (ii) the most important phases of scenario construction, (iii) the interconnection of scenario method with other methods of scenario construction, (iv) the profile of experts involved in foresight projects, (v) the profile of experts involved in scenario construction, (vi) the application of the triangulation principle in scenario construction, (vii) the application of wild cards in scenario construction and techniques to identify them, (viii) the average time of scenario construction process, (ix) the linkage of scenarios to other documents, (x) the number of scenarios elaborated upon, and (xi) the main difficulties in the process of scenario construction. To achieve article aims there have been used the following research methods: a literature review, the method of critical analysis and logical construction, survey research, the status of Polish foresight projects, interim and final report analysis. The research has been funded by the National Science Centre in Poland within a research project entitled Scenarios in future shaping and anticipation for foresight studies, project number: 4194/B/H03/2011/40.

Stedman, Nicole, e Amy Brown. "Critical thinking perspectives of undergraduate students". Advancements in Agricultural Development 1, n. 1 (17 gennaio 2020): 14–24. http://dx.doi.org/10.37433/aad.v1i1.29.

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Today’s learners need support in not only developing capacity for a global mindset, but also for thinking critically about the world. Employers are seeking graduates who can enter the workforce prepared to work within agriculture with the ability to understand its complexities. Higher education institutions have been called upon to provide this to students and faculty are often charged with this responsibility. However, faculty are often unprepared to provide this level of instruction and need support in order to foster this in the classroom. Student participants in this study were exposed to scenarios, which are a tool used to provide multiple perspectives and outcomes to real-life scenarios. Faculty used the scenarios to complement course instruction with respect to the impacts of climate change on food security and hunger. Using Facione’s (1990) framework for critical thinking skill, statements submitted by students both prior to the scenario and post were analyzed. It was found that while students demonstrated critical thinking in both the pre and post, the post statements were much richer, in-depth, and thoughtful in how critical thinking was demonstrated. This showed that faculty support, combined with innovative teaching methods, like scenarios, will encourage students’ building of capacity for critical thinking.

Pan, Xing, Lunhu Hu, Ziling Xin, Shenghan Zhou, Yanmei Lin e Yong Wu. "Risk Scenario Generation Based on Importance Measure Analysis". Sustainability 10, n. 9 (7 settembre 2018): 3207. http://dx.doi.org/10.3390/su10093207.

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A risk scenario is a combination of risk events that may result in system failure. Risk scenario analysis is an important part of system risk assessment and avoidance. In engineering activity-based systems, important risk scenarios are related to important events. Critical activities, meanwhile, mean risk events that may result in system failure. This article proposes these definitions of risk event and risk scenario based on the characteristics of risk in engineering activity-based systems. Under the proposed definitions, a risk scenario framework generated based on importance measure analysis is given, in which critical activities analysis, risk event identification, and risk scenario generation are the three main parts. Important risk events are identified according to activities’ uncertain importance measure and important risk scenarios are generated on the basis of a system’s critical activities analysis. In the risk scenario generation process based on importance analysis, the importance degrees of network activities are ranked to identify the subject of risk events, so that risk scenarios can be combined and generated by risk events and the importance of scenarios is analyzed. Critical activities are analyzed by Taguchi tolerance design, mathematical analysis, and Monte Carlo simulation methods. Then the degrees of uncertain importance measure of activities are solved by the three methods and these results are compared. The comparison results in the example show that the proposed method of uncertain importance measure is very effective for distinguishing the importance level of activities in systems. The calculation and simulation results also verify that the risk events composed of critical activities can generate risk scenarios.

Allidina, Tanvir, Lipika Deka, Daniel Paluszczyszyn e David Elizondo. "Selecting Non-Line of Sight Critical Scenarios for Connected Autonomous Vehicle Testing". Software 1, n. 3 (13 luglio 2022): 244–64. http://dx.doi.org/10.3390/software1030011.

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The on-board sensors of connected autonomous vehicles (CAVs) are limited by their range and inability to see around corners or blind spots, otherwise known as non-line of sight scenarios (NLOS). These scenarios have the potential to be fatal (critical scenarios) as the sensors may detect an obstacle much later than the amount of time needed for the car to react. In such cases, mechanisms such as vehicular communication are required to extend the visibility range of the CAV. Despite there being a substantial body of work on the development of navigational and communication algorithms for such scenarios, there is no standard method for generating and selecting critical NLOS scenarios for testing these algorithms in a scenario-based simulation environment. This paper puts forward a novel method utilising a genetic algorithm for the selection of critical NLOS scenarios from the set of all possible NLOS scenarios in a particular road environment. The need to select critical scenarios is pertinent as the number of all possible driving scenarios generated is large and testing them against each other is time consuming, unnecessary and expensive. The selected critical scenarios are then validated for criticality by using a series of MATLAB based simulations.

Ciuchi, S., e A. Crisanti. "Different scenarios for critical glassy dynamics". Europhysics Letters (EPL) 49, n. 6 (15 marzo 2000): 754–60. http://dx.doi.org/10.1209/epl/i2000-00215-y.

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Czimmermann, Peter, e Michal Kohani. "Characteristics of Changes of Transportation Performance for Pairs of Critical Edges". Communications - Scientific letters of the University of Zilina 20, n. 3 (30 settembre 2018): 84–87. http://dx.doi.org/10.26552/com.c.2018.3.84-87.

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When the robustness of a public service system design is tested, we can often use scenarios where possible random failures can occur and they can influence the time the service is accessible which is provided for system users. The construction of a suitable scenario is based on the choice of links of the transportation network which influence the system performance in a substantial way. In such scenarios one or multiple arcs can be affected by this failure. In our contribution we present characteristics of pairs of critical arcs that can be used to develop an algorithm for the creation of critical scenarios.

Cai, Jinkang, Weiwen Deng, Ying Wang, Haoran Guang, Jiangkun Li e Juan Ding. "Boundary Scenario Generation for HAVs Based on Classification and Local Sampling". Machines 11, n. 4 (27 marzo 2023): 426. http://dx.doi.org/10.3390/machines11040426.

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High-level Automated Vehicles (HAVs) are expected to improve traffic safety significantly. However, verifying and evaluating HAVs remains an open problem. Scenario-based testing is a promising method for HAV testing. Boundary scenarios exist around the performance boundary between critical and non-critical scenarios. Testing HAVs in these boundary scenarios is crucial to investigate why collisions cannot be avoided due to small changes in scenario parameters. This study proposes a methodology to generate diverse boundary scenarios to test HAVs. First, an approach is proposed to obtain at least one High-Performance Classifier (HPC) based on two classification algorithms that iteratively guide each other to find uncertain scenarios to improve their performance. Then, the HPC is exploited to find candidate scenarios highly likely to be boundary scenarios. To increase the efficiency of candidate scenario generation, a strategy based on local sampling is presented to find more diverse candidate scenarios based on a small number of them. Numerical experiments show that the HPCs acquired by the method proposed in this study can achieve a classification accuracy of 98% and 99% for random car-following and cut-in scenarios, respectively. Moreover, more than 86% of 271,744 candidate cut-in scenarios derived by local sampling are near the performance boundary.

Più fonti

Tesi sul tema "Critical scenarios":

Alam, Mohammad Saquib. "Automatic generation of critical driving scenarios". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-288886.

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Despite the tremendous development in the autonomous vehicle industry, the tools for systematic testing are still lacking. Real-world testing is time-consuming and above all, dangerous. There is also a lack of a framework to automatically generate critical scenarios to test autonomous vehicles. This thesis develops a general framework for end- to- end testing of an autonomous vehicle in a simulated environment. The framework provides the capability to generate and execute a large number of traffic scenarios in a reliable manner. Two methods are proposed to compute the criticality of a traffic scenario. A so-called critical value is used to learn the probability distribution of the critical scenario iteratively. The obtained probability distribution can be used to sample critical scenarios for testing and for benchmarking a different autonomous vehicle. To describe the static and dynamic participants of urban traffic scenario executed by the simulator, OpenDrive and OpenScenario standards are used.
Trots den enorma utvecklingen inom den autonoma fordonsindustrin saknas fortfarande verktygen för systematisk testning. Verklig testning är tidskrävande och framför allt farlig. Det saknas också ett ramverk för att automatiskt generera kritiska scenarier för att testa autonoma fordon. Denna avhandling utvecklar en allmän ram för end-to-end- test av ett autonomt fordon i en simulerad miljö. Ramverket ger möjlighet att generera och utföra ett stort antal trafikscenarier på ett tillförlitligt sätt. Två metoder föreslås för att beräkna kritiken i ett trafikscenario. Ett så kallat kritiskt värde används för att lära sig sannolikhetsfördelningen för det kritiska scenariot iterativt. Den erhållna sannolikhetsfördelningen kan användas för att prova kritiska scenarier för testning och för benchmarking av ett annat autonomt fordon. För att beskriva de statiska och dynamiska deltagarna i stadstrafikscenariot som körs av simulatorn används OpenDrive och OpenScenario-standarder.

Osman, Gihan. "Scaffolding critical discourse in online problem-based scenarios". [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3319916.

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Thesis (Ph.D.)--Indiana University, School of Education, 2008.
Title from PDF t.p. (viewed on May 13, 2009). Source: Dissertation Abstracts International, Volume: 69-08, Section: A, page: 3121. Adviser: Thomas M. Duffy.

Collin, Sofie. "Synthetic Data for Training and Evaluation of Critical Traffic Scenarios". Thesis, Linköpings universitet, Medie- och Informationsteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177779.

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Modern camera-based vehicle safety systems heavily rely on machine learning and consequently require large amounts of training data to perform reliably. However, collecting and annotating the needed data is an extremely expensive and time-consuming process. In addition, it is exceptionally difficult to collect data that covers critical scenarios. This thesis investigates to what extent synthetic data can replace real-world data for these scenarios. Since only a limited amount of data consisting of such real-world scenarios is available, this thesis instead makes use of proxy scenarios, e.g. situations when pedestrians are located closely in front of the vehicle (for example at a crosswalk). The presented approach involves training a detector on real-world data where all samples of these proxy scenarios have been removed and compare it to other detectors trained on data where the removed samples have been replaced with various degrees of synthetic data. A method for generating and automatically and accurately annotating synthetic data, using features in the CARLA simulator, is presented. Also, the domain gap between the synthetic and real-world data is analyzed and methods in domain adaptation and data augmentation are reviewed. The presented experiments show that aligning statistical properties between the synthetic and real-world datasets distinctly mitigates the domain gap. There are also clear indications that synthetic data can help detect pedestrians in critical traffic situations

Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet

Rezvani, Arany Roushan. "Gaussian Process Model Predictive Control for Autonomous Driving in Safety-Critical Scenarios". Thesis, Linköpings universitet, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-161430.

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This thesis is concerned with model predictive control (MPC) within the field of autonomous driving. MPC requires a model of the system to be controlled. Since a vehicle is expected to handle a wide range of driving conditions, it is crucial that the model of the vehicle dynamics is able to account for this. Differences in road grip caused by snowy, icy or muddy roads change the driving dynamics and relying on a single model, based on ideal conditions, could possibly lead to dangerous behaviour. This work investigates the use of Gaussian processes for learning a model that can account for varying road friction coefficients. This model is incorporated as an extension to a nominal vehicle model. A double lane change scenario is considered and the aim is to learn a GP model of the disturbance based on previous driving experiences with a road friction coefficient of 0.4 and 0.6 performed with a regular MPC controller. The data is then used to train a GP model. The GPMPC controller is then compared with the regular MPC controller in the case of trajectory tracking. The results show that the obtained GP models in most cases correctly predict the model error in one prediction step. For multi-step predictions, the results vary more with some cases showing an improved prediction with a GP model compared to the nominal model. In all cases, the GPMPC controller gives a better trajectory tracking than the MPC controller while using less control input.

Nitsche, Philippe. "Safety-critical scenarios and virtual testing procedures for automated cars at road intersections". Thesis, Loughborough University, 2018. https://dspace.lboro.ac.uk/2134/34433.

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This thesis addresses the problem of road intersection safety with regard to a mixed population of automated vehicles and non-automated road users. The work derives and evaluates safety-critical scenarios at road junctions, which can pose a particular safety problem involving automated cars. A simulation and evaluation framework for car-to-car accidents is presented and demonstrated, which allows examining the safety performance of automated driving systems within those scenarios. Given the recent advancements in automated driving functions, one of the main challenges is safe and efficient operation in complex traffic situations such as road junctions. There is a need for comprehensive testing, either in virtual testing environments or on real-world test tracks. Since it is unrealistic to cover all possible combinations of traffic situations and environment conditions, the challenge is to find the key driving situations to be evaluated at junctions. Against this background, a novel method to derive critical pre-crash scenarios from historical car accident data is presented. It employs k-medoids to cluster historical junction crash data into distinct partitions and then applies the association rules algorithm to each cluster to specify the driving scenarios in more detail. The dataset used consists of 1,056 junction crashes in the UK, which were exported from the in-depth On-the-Spot database. The study resulted in thirteen crash clusters for T-junctions, and six crash clusters for crossroads. Association rules revealed common crash characteristics, which were the basis for the scenario descriptions. As a follow-up to the scenario generation, the thesis further presents a novel, modular framework to transfer the derived collision scenarios to a sub-microscopic traffic simulation environment. The software CarMaker is used with MATLAB/Simulink to simulate realistic models of vehicles, sensors and road environments and is combined with an advanced Monte Carlo method to obtain a representative set of parameter combinations. The analysis of different safety performance indicators computed from the simulation outputs reveals collision and near-miss probabilities for selected scenarios. The usefulness and applicability of the simulation and evaluation framework is demonstrated for a selected junction scenario, where the safety performance of different in-vehicle collision avoidance systems is studied. The results show that the number of collisions and conflicts were reduced to a tenth when adding a crossing and turning assistant to a basic forward collision avoidance system. Due to its modular architecture, the presented framework can be adapted to the individual needs of future users and may be enhanced with customised simulation models. Ultimately, the thesis leads to more efficient workflows when virtually testing automated driving at intersections, as a complement to field operational tests on public roads.

Fredström, Linna. "Reimagining climate futures : Using critical futures studies to explore scenarios for Ljungby municipality in Sweden". Thesis, Stockholms universitet, Stockholm Resilience Centre, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-194398.

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A growing body of research is calling for radical transformation of society to avoid catastrophic levels of climate change and create a more sustainable and just future. To make this possible, climate researcher will need new approaches and methods that help envision and enable transformations. In this thesis I explore how transformative scenario studies can incorporate critical social theory to enable more reflexive and actionable results. I develop climate change scenarios for a Swedish municipality and adopt a novel combination of the Manoa method and causal layered analysis. This methodological contribution, combining the creativity of the Manoa method and critical perspective of causal layered analysis, is coupled with a transdisciplinary approach. Through collaboration with local actors, including political, private, and civil society representatives, the study maximizes the relevance of the results to the local community. Building on the area’s cultural heritage of oral storytelling, the final scenarios are developed in collaboration with local storytellers and presented back to the community as a set of short stories. The study makes two noteworthy contributions. First, by allowing local context and culture to guide the creation and dissemination of results the study shows the power of a transdisciplinary approach. Second, by applying a critical theory lens, the study unveils how underlying assumptions limit our capacity to imagine different futures and that challenging these assumptions can increase the transformative potential of scenario research.

Tan, Kaige. "Building verification database and extracting critical scenarios for self-driving car testing on virtual platform". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-263927.

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This degree project, conducted at Volvo Cars, investigates a method about how to build a test database for an Autonomous Driving (AD) function on a virtual platform and how to extract critical scenarios from the test database to finish test cases reduction through optimization. The virtual platform under study is the model-in-the-loop (MIL) based Simulation Platform Active Safety (SPAS) environment and the optimization tool being used is modeFrontier. The analyzing process, in which three levels of abstraction for scenarios are proposed in order to fulfill all requirements for an AD function, is followed in the project to build the test database. Application is carried out to transform requirements from a specific Operational Design Domain (ODD) and linguistic representation into a test suite which contains concrete scenarios and test cases. A meta-model is built to help analyze system structure and parameter requirements in the level of logical scenarios. The practicability of a scenario-based approach for the design of AD function test cases generation is demonstrated with the example of building Traffic Congestion Support (TCS) test database. Obtaining the test database and the successful analysis of parameters for the TCS function on the MIL platform lead to the main goal of the thesis project, which is finding edge cases in the test database by optimizing objective functions. By defining the objective functions and building the workflow in modeFrontier after trying with different methods, the optimization process is implemented with two different algorithms separately. pilOPT is evaluated as a better solution for AD function than Multi-Objective Simulated Annealing (MOSA) in terms of computational time and edge cases finding. In addition, a noise model is added to ideal sensor model in SPAS to study the influence of noise in real test track. The result shows a big difference in Time-toCollision value, which is a defined objective function in the project. This indicates more test cases are deteriorated to critical scenario if noise is taken into consideration, which shows the influence of noise cannot be neglected during testing.
Detta examensarbete, genomfört hos Volvo Cars, undersöker en uppbyggnadsmetod av en testdatabas för Autonomous Driving (AD) på en virtuell plattform och hur man bör extrahera kritiska scenarier från testdatabasen för att reducera antalet testfall genom optimering. Den aktuella virtuella plattformen är den model-in-the-loop (MIL) baserade Simulation Platform Active Safety (SPAS) miljön och optimeringsverktyget som användes är modeFrontier. Analysprocessen, i vilken tre abstraktionsnivåer för scenarier är föreslagna i syfte att satisfiera alla kraven för AD, redogörs för i detta projekt. Tillämpning har genomförts för att transformera krav från en specifik Operational Design Domain (ODD) samt lingvistisk representation till en testsvit som innehåller konkreta scenarier och testfall. En metamodell har konstruerats för att assistera med analysen av systemstrukturen och parameterkraven i nivån av logiska scenarier. Genomförbarheten av en scenariobaserad infallsvinkel för designen av AKF-testfall demonstreras med exemplet av konstruktionen av Traffic Congestion Support (TCS)- testdatabasen. Erhållandet av testdatabasen och den framgångsrika analysen av parametrarna för TCSfunktionen på MIL-plattformen ledde till det huvudsakliga målet med examenarbetet, vilket var att identifiera kantfall i testdatabasen genom att optimera objektfunktioner. Genom att definiera objektfunktionerna och konstruera arbetsflödet i modeFrontier efter flertalet försök med olika metoder, implementerades optimeringsprocessen med tvåseparata algoritmer. pilOPT evalueras som en bättre lösning för AD jämfört med Multi-Objective Simulated Annealing (MOSA) med avseende på beräkningstid och identifiering av kantfall. Dessutom har brus adderats till den ideala sensormodellen i SPAS för att studera inflytandet av brus i en verklig testmiljö. Resultaten visar på en stor skillnad i tid-till-kollisionsvärde, vilket är en väldefinierad objektfunktion i projektet. Detta indikerar att fler testfall har försämrats till ett kritiskt scenario om brus tas man tar hänsyn till brus, vilket visar på att inflytandet av brus inte kan försummas under testning.

Jose, Anita Ann. "Economic evaluation of small wind generation ownership under different electricity pricing scenarios". Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/7075.

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Master of Science
Department of Electrical and Computer Engineering
Anil Pahwa
With the Smart Grid trend setting in, various techniques to make the existing grid smarter are being considered. The price of electricity is one of the major factors, which affects the electric utility as well as the numerous consumers connected to the grid. Therefore deciding the right price of electricity for the time of day would be an important decision to make. Consumers’ response to this change in price will impact peak demand as well as their own annual energy bill. Owning a small wind generator under the Critical Peak Pricing (CPP) and Time of Use (TOU) price-based demand response programs could be a viable option. Economic evaluation of owning a small wind generator under the two pricing schemes, namely Critical Peak Pricing (CPP) and Time of Use (TOU), is the main focus of this research. Analysis shows that adopting either of the pricing schemes will not change the annual energy bill for the consumer. Taking into account the installed cost of the turbine, it may not be significantly economical for a residential homeowner to own a small wind turbine with either of the pricing schemes in effect under the conditions assumed.

Bessani, Michel. "Resilience and vulnerability of power distribution systems: approaches for dynamic features and extreme weather scenarios". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18153/tde-11072018-165318/.

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Our society is heavily dependent on commodities, as water and electricity, supplied to final users by engineered systems, which are known as critical infrastructures. In such context, the understanding of how such systems handle damaging events is an important aspect and is a current concern of researchers, public agents, and society. How much of performance a system loses due to damages is related to its vulnerability, and the ability to absorb and recover successfully from damages is its resilience. In this study, approaches to assess the vulnerability and resilience of power distribution systems by evaluating dynamic features, as the processes of failure and repair, and system reconfiguration for vulnerability, and the effects of extreme weather scenarios for resilience together with the processes of failure of repair are presented. Such approaches were applied on systems previously presented in the literature, and also on a Brazilian power distribution system. A Monte Carlo simulation was applied to evaluate this systems, models for time-to-failure and time-to-repair under different circumstances were obtained from historical data, and a method to use the models of time-to-failure during the vulnerability analysis was introduced. In addition, an assessment of the impact of reconfiguration capability on vulnerability is also carried out, and a resilience assessment under different climate scenarios has been developed. The time-to-failure and repair models highlighted how external factors modifies the Brazilian system failure and repair dynamics, the use of time-to-failure models during vulnerability analysis showed that the consideration of the failure dynamic of the types of elements give different results, and the time domain allows new analysis\' perspectives. The investigation indicated that the vulnerability reduction due to reconfiguration is affected by the number of switches and also the maximum load capacity of the distribution system feeders. The resilience assessment showed that for structural connectivity, larger distribution networks are less resilient, while for electricity delivery, a set of features, related with the topological and electrical organization of such networks, seems to be associated with the network service resilience, such information is useful for system planning and management. The dynamics evaluated in this study are relevant to vulnerability and resilience of such systems, and also to other critical infrastructures. Moreover, the developed approaches can be applied to other systems, as transportation and water distribution. In future studies, other power distribution systems features, as distributed generation and energy storage, will be considered in both, vulnerability and resilience analysis.
Nossa sociedade é altamente dependente de commodities, como água e eletricidade, fornecidas para os usuários por sistemas de engenharia, conhecidos como infraestruturas críticas. A compreensão de como tais sistemas lidam com eventos prejudiciais é uma preocupação atual de pesquisadores, agentes públicos e sociedade. A perda de desempenho de um sistema devido a danos é relacionada à sua vulnerabilidade, e a capacidade de absorver e se recuperar dos danos é a resiliência. Neste estudo, são apresentadas abordagens para avaliar a vulnerabilidade e resiliência de sistemas de distribuição de energia considerando características dinâmicas, como os processos de falha e reconfiguração do sistema, para a vulnerabilidade, e os efeitos de climas extremos na resiliência com os processos de falha e reparo. Tais abordagens foram aplicadas em sistemas previamente apresentados na literatura, e também em um sistema brasileiro. Simulação de Monte Carlo foi utilizada para avaliar as dinâmicas de falha e reparo do sistema utilizando de modelos obtidos a partir de dados históricos, e um método para usar os modelos de tempo-até-falha durante a análise de vulnerabilidade também foi apresentado. Além disso, uma avaliação do impacto da dinâmica de reconfiguração na vulnerabilidade foi realizada e uma avaliação de resiliência sob diferentes cenários climáticos foi desenvolvida. Os modelos tempo-para-falha e reparo destacaram como fatores externos modificam as dinâmicas de falha e reparo do sistema brasileiro, o uso de modelos de confiabilidade na análise de vulnerabilidades mostrou que a consideração dos diferentes tipos de elementos geram resultados diferentes e o domínio de tempo permite novas perspectivas de análise. A investigação da reconfiguração indicou que a redução da vulnerabilidade devido à reconfiguração é afetada pelo número de chaves e também pela máxima capacidade de carga dos alimentadores do sistema de distribuição. A avaliação de resiliência mostrou que, para conectividade estrutural, redes de distribuição maiores são menos resilientes, enquanto que para fornecimento de energia, um conjunto de características, relacionados com a organização topológica e elétrica dessas redes parece ser associado à resiliência do serviço, informação útil para o planejamento. As dinâmicas avaliadas neste estudo são relevantes para a vulnerabilidade e resiliência de tais sistemas, e também para outras infraestruturas críticas. Além disso, essas abordagens podem ser aplicadas a outros sistemas, como transporte e distribuição de água. Em estudos futuros, outras características de sistemas de distribuição de energia, como geração distribuída e armazenamento de energia, serão consideradas nas análises de vulnerabilidade e resiliência.

CASTRO, ABEL ARRIETA. "DEVELOPMENT OF A ROBUST AND FAULT TOLERANT INTEGRATED CONTROL SYSTEM TO IMPROVE THE STABILITY OF ROAD VEHICLES IN CRITICAL DRIVING SCENARIOS". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33168@1.

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Abstract (sommario):

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
PROGRAMA DE EXCELENCIA ACADEMICA
Atualmente, as novas tecnologias estão estendendo os limites físicos dos veículos automotivos em busca de mais segurança e comforto. Novas aplicações, como por exemplo veículos autônomos, exigem sistemas de controle capazes de garantir a estabilidade do veículo durante a condução autônoma ou em cenários perigosos. Na maioria dos carros modernos, os sistemas de controle atuam de forma independente, ou seja, não há coordenação ou compartilhamento de dados entre eles, pois poderiam produzir conflitos entre esses controladores. Desse modo, nenhuma melhoria na estabilidade do veículo é alcançada ou inclusive, piores cenários podem ser produzidos. Para superar esses problemas, uma abordagem integrada é projetada neste trabalho. Esta integração, definida como sistema de controle integrado (IC), usa uma regra para coordenar o programa eletrônico de estabilidade (ESP em inglês) e o sistema de direção de quatro rodas (4WS em inglês). O ESP realiza uma frenagem seletiva dependendo do estado atual do veículo. Esta condição é estimada pela diferença entre a taxa de guinada desejada, obtida usando um modelo linear do veículo, e a taxa de guinada real. Adicionalmente, as pressões de frenagem em cada roda são calculadas pelo sistema de travagem antibloqueio (ABS em inglês). Neste trabalho, uma lógica de comutação on-off e um modelo hidráulico de primeira ordem são empregadas para modelar o sistema ABS. Para projetar o 4WS, usou-se uma estratégia por alimentação direta que considera o ângulo de esterçamento das roas frontais. Finalmente, para testar as vantagens do sistema IC proposto nesta tese contra o enfoque não integrado, realizaram-se simulações considerando um modelo não-linear do veículo em cenários críticos de condução. O modelo do veículo foi derivado empregando a abordagem multicorpos e o princípio de Jourdain, e depois é validado usando um conjunto de dados experimentais obtidos por sensores montados em um carro a escala.
Nowadays new technologies are pushing the road vehicle limits further. Promising applications, e.g. self-driving cars, requires control systems that are able to ensure the vehicle s stability during autonomous driving or under dangerous scenarios. In most of modern cars, the control systems actuates independently, i.e. there is no coordination or data sharing between them. This approach can produce conflicts between these standalone controllers, thereby no improvements on the vehicle s stability are achieved or even a worse scenario can be produced. In order to overcome these problems, an integrated approach is designed in this work. This integration, defined as Integrated control system (IC), use a rule to coordinate the Electronic stability program (ESP) and the Four-wheel steering system (4WS). The ESP performs a selective braking depending of the current state of the vehicle. This condition is estimated by the difference between the desired yaw rate, obtained using a linear vehicle model, and the actual yaw rate. In addition, the braking pressures at each wheel are computed by the Anti-lock braking system (ABS). In this work, an on-off switching logic and a firstorder hydraulic model are employed to model the ABS system. To model the 4WS, a simple feed-forward control strategy that consider the front steering as input is used. Finally, in order to test the advantages of the IC system against the non-integrated one, simulations considering a nonlinear vehicle model under critical driving scenarios were performed. The vehicle model was derived employing the multibody approach and the Jourdain s principle, and then it is validated using a set of experimental data obtained by sensors mounted on a scaled car.

Più fonti

Libri sul tema "Critical scenarios":

Szende, Peter. Case scenarios in hospitality supervision. Clifton Park, NY: Delmar Cengage Learning, 2010.

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Kynell-Hunt, Teresa. Scenarios for technical communication: Critical thinking and writing. Boston: Allyn and Bacon, 1999.

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McWhorter, Kathleen T. Pathways writing scenarios: Sentences to paragraphs. 2^a ed. New York: Pearson/Longman, 2010.

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McWhorter, Kathleen T. Pathways: Scenarios for sentence and paragraph writing. 3^a ed. New York: Pearson, 2011.

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Jr, Wright J. W., e Drake Laura, a cura di. Economic and political impediments to Middle East peace: Critical questions and alternative scenarios. New York: St. Martin's Press, 2000.

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McWhorter, Kathleen T. Pathways for writing scenarios: From sentence to paragraph. New York: Pearson/Longman, 2007.

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McWhorter, Kathleen T. Pathways for writing scenarios: From sentence to paragraph. 2^a ed. New York: Pearson Longman, 2009.

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Rossini, Gioacchino. Tancredi: Melodramma eroica in two acts : reduction forvoice and piano based on the critical edition of the orchestral score published by the Fondazione Rossini of Pesaro edited by Philip Gossett. Milano: G. Ricordi, 1991.

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Broderick, Mick. Nuclear movies: A critical analysis and filmography of international feature length films dealing with experimentation, aliens, terrorism, holocaust, and other disaster scenarios, 1914-1989. Jefferson, N.C: McFarland & Co., 1991.

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Teutișan, Călin. Scenarii ale criticii: Protagoniști, metode, interpretări. Cluj-Napoca: Editura Şcoala Ardeleană, 2021.

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Capitoli di libri sul tema "Critical scenarios":

Stoltzfus, William. "Epilogue: Critical Questions and Alternative Scenarios". In Economic and Political Impediments to Middle East Peace, 241–45. London: Palgrave Macmillan UK, 2000. http://dx.doi.org/10.1057/9780333994269_15.

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Armstrong, Helen L., e John Davey. "Assembling Competitive Intelligence Using Classroom Scenarios". In Security Education and Critical Infrastructures, 159–67. New York, NY: Springer US, 2003. http://dx.doi.org/10.1007/978-0-387-35694-5_15.

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Xie, Jingquan, Betim Sojeva, Erich Rome e Daniel Lückerath. "Towards a Common Vocabulary for Crisis Management Scenarios". In Critical Information Infrastructures Security, 25–36. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99843-5_3.

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Eid, Mohamed, e Vittorio Rosato. "Critical Infrastructure Disruption Scenarios Analyses via Simulation". In Managing the Complexity of Critical Infrastructures, 43–61. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-51043-9_3.

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Kirkpatrick, James R. "Stories of Critical and Lethal Medical Scenarios". In Medical Crises in Eating Disorders, 46–94. New York: Routledge, 2022. http://dx.doi.org/10.4324/9781003053088-2.

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Amado, Eduardo Diaz. "Critical Bioethical Approach to Health Crisis Scenarios". In Bioethics, 165–82. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003269885-13.

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Satizábal, Cristina, Rafael Páez e Jordi Forné. "PROSEARCH: A Protocol to Simplify Path Discovery in Critical Scenarios". In Critical Information Infrastructures Security, 151–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11962977_13.

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Alcaraz, Cristina, e Rodrigo Roman. "Applying Key Infrastructures for Sensor Networks in CIP/CIIP Scenarios". In Critical Information Infrastructures Security, 166–78. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11962977_14.

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Harb, Ammer. "The Critical Forms of Design Futures Scenarios: Introducing Unconventional Ways of Scenarios Making". In Springer Series in Design and Innovation, 367–76. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-49811-4_35.

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AbstractThis paper discusses the critical forms of design futures scenarios; these forms aim at debating, interrogating, and questioning future visions rather than extrapolating on the status quo. They aim to problematize future issues in order to enact social change and mitigate the consequences and implications of today’s actions and decisions.

Klampfl, Lorenz, e Franz Wotawa. "Identifying Critical Scenarios in Autonomous Driving During Operation". In Communications in Computer and Information Science, 156–72. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-50396-2_9.

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Atti di convegni sul tema "Critical scenarios":

Klischat, Moritz, Edmond Irani Liu, Fabian Holtke e Matthias Althoff. "Scenario Factory: Creating Safety-Critical Traffic Scenarios for Automated Vehicles". In 2020 IEEE 23rd International Conference on Intelligent Transportation Systems (ITSC). IEEE, 2020. http://dx.doi.org/10.1109/itsc45102.2020.9294629.

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Menzel, Thaddäus, e Thiago de Borba. "Methodology for Automated Definition of Critical Scenarios". In FISITA World Congress 2021. FISITA, 2021. http://dx.doi.org/10.46720/f2020-acm-073.

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The field of automated driving has been the focus of research in both, academia and industry in the recent decades. Thanks to the advancements in sensor technology currently used for Advanced Driver Assistance Systems (ADAS), automatization of several parts of the driving task was enabled. However, the introduction of new technologies into the market requires a testing phase. Different test methods can be applied to assess the automated driving functions and their features. Nevertheless, the systematic test of functions for driver assistance systems requires the identification and analysis of a huge number of traffic scenarios. Since most traffic scenarios are not challenging, an approach that automatically generates critical driving scenarios can reduce the testing efforts and costs. This paper presents a methodology for automated definition of critical scenarios, which is composed of seven steps: define a critical maneuver, define the logical scenario, model the critical maneuver using a mathematical description, define the assessment criteria, obtain the concrete scenarios, specify a performance improvement method, and obtain the boundary scenarios. Firstly, Independent if the validation/homologation is based on a virtual or a field test, the tests should be focused on the most critical situations, since the test phase is costly. The selection of critical scenarios, based on critical maneuvers, is an important phase to develop testing methods. Thus, the critical maneuver selected was the lane change maneuver. The logical scenario defined describes the event where Ego drives in highway, presenting certain speed and acceleration, and due to a traffic jam, the front vehicle and the rear vehicle, on the adjacent lane, are stationary and there is a considerable distance between Ego and the rear vehicle. After, the mathematical modelling of the lane change maneuver was performed. Composed of three parts, the trajectory planning, which is responsible to generate the desired trajectory that ensure a safe lane change maneuver based on different driver style, the second is the vehicle model, which describes the longitudinal and lateral motion of the Ego vehicle, and the last is the driver model, which is responsible to drive Ego vehicle along to the planned trajectory. The assessment criteria was based on the safety distances and on the maximum lateral acceleration performed during the maneuver. The concrete scenarios were generated by variating three parameters, in this case, relative velocity between Ego and the front vehicle, the distance between Ego and the front vehicle, and alpha, the coefficient that affects the lane change time. Then, the performance improvement approach was applied, using the k-Nearest Neighbor Classifier, to reduce the computational elapsed time. After completing the first six steps, the concrete scenarios have been classified as critical and non-critical. Lastly, through the analysis of each neighbor point, it was possible to reduce the result space, to a few number of scenarios that can be easily manipulated, the boundary scenarios. Thus, the proposed methodology shown to be an efficient method for the definition of critical scenarios, since thousands of scenarios could be generated and classified in a matter of seconds.

Balazs Andras Lajtha e Gabor Feher. "Connection establishment in time critical scenarios". In 2012 XVth International Telecommunications Network Strategy and Planning Symposium (NETWORKS). IEEE, 2012. http://dx.doi.org/10.1109/netwks.2012.6381713.

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Fang, Xiaowei, Zhixiong Ma, Xichan Zhu e Qi Yin. "Critical Scenarios Based on Graded Hazard Disposal Model of Human Drivers". In SAE 2023 Intelligent and Connected Vehicles Symposium. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-7054.

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<div class="section abstract"><div class="htmlview paragraph">In order to improve the efficiency of safety performance test for intelligent vehicles and construct the test case set quickly, critical scenarios based on graded hazard disposal model of human drivers are proposed, which can be used for extraction of test cases for safety performance. Based on the natural driving data in China Field Operational Test (China-FOT), the four-stage collision avoidance process of human drivers is obtained, including steady driving stage, risk judgment stage, collision reaction stage and collision avoidance stage. And there are two human driver states: general state and alert state. Then the graded hazard disposal model of human drivers is constructed. According to the parameter distribution of natural driving data, the risk perception point, risk response point and collision reaction time of deceleration scenario and cut-in scenario are obtained, and the deceleration gradient and the maximum deceleration of each collision avoidance difficulty level are determined. For deceleration scenario and cut-in scenario, the parameter range is determined to generalize logical scenarios. Then based on the graded hazard disposal model of human drivers, the critical scenarios at the preventable and unpreventable boundaries are obtained through simulation calculation. As the concrete scenarios with high value for safety extracted from the massive logical scenarios, the critical scenarios are used to construct the test case set in the safety performance test for intelligent vehicles. For deceleration scenario, 507 critical scenarios are obtained from 10,000 logical scenarios, which increases the test efficiency by 19.72 times. For cut-in scenario, 5,121 critical scenarios are obtained from 270,000 logical scenarios, which increases the test efficiency by 52.72 times.</div></div>

Boudi, Zakaryae, El Miloudi El Koursi e Simon Collart-Dutilleul. "An HCPN Pattern for Railway Safety Critical Scenarios Formal Modeling". In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5687.

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Analyzing railway critical scenarios usually involves a large team of diverse railway abilities and skills. This paper presents a formal modeling pattern for Hierarchical Colored Petri Nets (HCPN) in modeling railway safety critical scenarios. Indeed, under the French project called “PERFECT”, our long-term objective is to formalize and automate a significant part of railway scenarios modeling. The purpose of this contribution is to bring a first proposition of a standardized modeling way able to deal with the models complexity resulting from the various modeling capabilities for railway scenarios. In fact, HCPN modeling freedom is preventing from accurate information aggregation and a beneficial use of those models in an overall safety analysis. The proposed pattern is based on modular High Level Petri Nets and consists in describing all the railway scenario episodes while incorporating most relevant safety components of the system, such as safety regulation procedures, interlocking and even human involvement, enabling a larger gathering of information and allowing the study of diverse issues in a same global model. This work intends to bring a concrete and reusable HCPN pattern for modeling in order to facilitate studies of accidental scenarios considering automatic mechanisms and human tasks. A concrete application of the pattern was made for the real accidental scenario of “Saint Romain en Gier”.

Gambi, Alessio, Vuong Nguyen, Jasim Ahmed e Gordon Fraser. "Generating Critical Driving Scenarios from Accident Sketches". In 2022 IEEE International Conference On Artificial Intelligence Testing (AITest). IEEE, 2022. http://dx.doi.org/10.1109/aitest55621.2022.00022.

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Clauss, Günther F., Marco Klein, Carlos Guedes Soares e Nuno Fonseca. "Response Based Identification of Critical Wave Scenarios". In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83861.

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In the last years the identification and investigation of critical wave sequences regarding offshore structure responses became one of the main topics in the ocean engineering community. Thereby the area of interest covers the entire field of application spectra at sea — from efficient and economic offshore operations in moderate sea states to reliability as well as survival in extreme wave conditions. For most cases, the focus lies on limiting criteria for the design, such as maximum global loads, maximum relative motions between two or more vessels or maximum accelerations, at which the floating structure has to operate or to survive. These criteria are typically combined with a limiting characteristic sea state (Hs, Tp) or a rogue wave. For the investigation of offshore structures as well as the identification of critical wave sequences, different approaches are available — most of them are based on linear transfer functions as it is an efficient procedure for the fast holistic evaluation. But, for some cases the linear method approach implies uncertainties due to nonlinear response behavior, in particular in extreme wave conditions. This paper presents an approach to these challenges, a response based optimization tool for critical wave sequence detection. This tool, which has been successfully introduced for the evaluation of the applicability of a multi-body system based on the linear method approach, is adjusted to a nonlinear task — the vertical bending moment of a chemical tanker in extreme wave conditions. Therefore a nonlinear strip theory solver is introduced into the optimization routine to capture the nonlinear effects on the vertical bending moment due to steep waves acting on large bow flares. The goal of the procedure is to find a worst case wave sequence for a certain critical sea state. This includes intensive numerical investigation as well as model test validation.

Sadou, Nabil, e Hamid Demmou. "Minimality of Critical Scenarios in Petri Net Models". In 2006 IEEE International Conference on Systems, Man and Cybernetics. IEEE, 2006. http://dx.doi.org/10.1109/icsmc.2006.384648.

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Di Vito, Piera, Daniel Fischer, Mariella Spada, Rita Rinaldo e Laurence Duquerroy. "HAPs Operations and Service provision in Critical Scenarios". In 15th International Conference on Space Operations. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2018. http://dx.doi.org/10.2514/6.2018-2504.

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Holtrup, Gerrit, William Blonay, Martin Strohmeier, Alain Mermoud, Jean-Pascal Chavanne e Vincent Lenders. "Modeling 5G Threat Scenarios for Critical Infrastructure Protection". In 2023 15th International Conference on Cyber Conflict: Meeting Reality (CyCon). IEEE, 2023. http://dx.doi.org/10.23919/cycon58705.2023.10182173.

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Rapporti di organizzazioni sul tema "Critical scenarios":

Marshak, Ronni. Streamline Customers' Critical Scenarios. Boston, MA: Patricia Seybold Group, febbraio 2010. http://dx.doi.org/10.1571/ht02-11-10cc.

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Sullivan, J. L., T. Stephens e M. Wang. Geothermal Power Production: Alternative Scenarios and Critical Issues. Office of Scientific and Technical Information (OSTI), maggio 2014. http://dx.doi.org/10.2172/1132252.

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Gates, Linda P. Strategic Planning with Critical Success Factors and Future Scenarios: An Integrated Strategic Planning Framework. Fort Belvoir, VA: Defense Technical Information Center, novembre 2010. http://dx.doi.org/10.21236/ada532574.

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Varin, Priam, Yishen Sun e Wesley Garey. Test scenarios for mission critical push-to-talk (MCPTT) off-network mode protocols implementation. Gaithersburg, MD: National Institute of Standards and Technology, ottobre 2018. http://dx.doi.org/10.6028/nist.ir.8236.

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Runyon, Amber, Gregor Schuurman, Brecken Robb, Jeremy Littell, Mark Miller e Joel Reynolds. Climate-resource scenarios to inform climate change adaptation in Wrangell-St. Elias National Park and Preserve: Summary of 2021 climate change scenario planning. National Park Service, 2024. http://dx.doi.org/10.36967/2301920.

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This report illustrates use of scenario planning as a climate change adaptation tool supporting Wrangell-St. Elias National Park and Preserve?s Resource Stewardship Strategy. The primary objective of scenario planning is to help resource managers and scientists make management and planning decisions informed by assessments of critical future uncertainties. This report outlines a process that synthesized future climate projections into three distinct but plausible and relevant climate summaries for the focal area and used them to develop climate-resource scenarios through participatory scenario planning. Initial steps identified the priority resource management topics and the corresponding related climate uncertainties. Next, local climate summaries were used to develop divergent climate futures: those that describe the broadest possible range of plausible conditions while capturing relevant uncertainty. The final phase further developed the climate futures and their resource implications. These participatory scenario planning exercises occurred virtually in fall (August?November) 2021. The climate-resource scenarios informed adaptation strategies in conjunction with the park?s Resource Stewardship Strategy development. The scope and complexity of this effort is unique but elements from the scenarios and resource implications have broad applicability to other large, protected areas in Alaska and Northwest Canada.

Engelke, Peter, David Bohl, Andrea Saldarriaga Jiménez e Jason Marczak. Latin America and the Caribbean 2030: Future Scenarios. Inter-American Development Bank, dicembre 2016. http://dx.doi.org/10.18235/0006521.

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Strategic foresight is critical to moving a country or region in the right direction. Leaders nearly everywhere in the world are overwhelmed by the crush of events, focusing their attention on the present rather than thelong term. Latin America and the Caribbean is no different. But complacency in thinking and planning for the future can no longer be the status quo. At a moment of profound regional and global transformation, the time is now to seize on policy directions that are most likely to take the region in the right direction. While Latin America and the Caribbean has many challenges, through foresight and strategy it could boost its position in the world -as Asia has done already. This publication makes the case for doing just that. Latin America has made incredible economic and political progress over the past decade. The prolonged commodity boom in the 2000s fueled higher growth rates than the Organisation for Economic Co-operation and Development (OECD) average and generated a dramatic drop in the poverty rate and a huge explosion of the middle class. Today, 288 million, or one in three people, are considered middle class. At the same time, with a few notable exceptions, democratic institutions are stronger, with universal suffrage and regular elections now largely the norm. The key question for the future is whether the region can maintain momentum, particularly with China's slowing growth. The end of the commodity boom exposed underlying structural problems in Latin America and the Caribbean. Fiscal and institutional concerns, as well as other social and economic questions, were laid bare. Not only do the next nearly fifteen years require us to solve lingering issues that remain from the mid-teens, but a new direction must be charted so the region can maximize its inherent advantages and best compete in a rapidly changing world.

Bäumler, Maximilian, e Matthias Lehmann. Generating representative test scenarios: The FUSE for Representativity (fuse4rep) process model for collecting and analysing traffic observation data. TU Dresden, 2024. http://dx.doi.org/10.26128/2024.2.

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Scenario-based testing is a pillar of assessing the effectiveness of automated driving systems (ADSs). For data-driven scenario-based testing, representative traffic scenarios need to describe real road traffic situations in compressed form and, as such, cover normal driving along with critical and accident situations originating from different data sources. Nevertheless, in the choice of data sources, a conflict often arises between sample quality and depth of information. Police accident data (PD) covering accident situations, for example, represent a full survey and thus have high sample quality but low depth of information. However, for local video-based traffic observation (VO) data using drones and covering normal driving and critical situations, the opposite is true. Only the fusion of both sources of data using statistical matching can yield a representative, meaningful database able to generate representative test scenarios. For successful fusion, which requires as many relevant, shared features in both data sources as possible, the following question arises: How can VO data be collected by drones and analysed to create the maximum number of relevant, shared features with PD? To answer that question, we used the Find–Unify–Synthesise–Evaluation (FUSE) for Representativity (FUSE4Rep) process model.We applied the first (“Find”) and second (“Unify”) step of this model to VO data and conducted drone-based VOs at two intersections in Dresden, Germany, to verify our results. We observed a three-way and a four-way intersection, both without traffic signals, for more than 27 h, following a fixed sample plan. To generate as many relevant information as possible, the drone pilots collected 122 variables for each observation (which we published in the ListDB Codebook) and the behavioural errors of road users, among other information. Next, we analysed the videos for traffic conflicts, which we classified according to the German accident type catalogue and matched with complementary information collected by the drone pilots. Last, we assessed the crash risk for the detected traffic conflicts using generalised extreme value (GEV) modelling. For example, accident type 211 was predicted as happening 1.3 times per year at the observed four-way intersection. The process ultimately facilitated the preparation of VO data for fusion with PD. The orientation towards traffic conflicts, the matched behavioural errors and the estimated GEV allowed creating accident-relevant scenarios. Thus, the model applied to VO data marks an important step towards realising a representative test scenario database and, in turn, safe ADSs.

Bäumler, Maximilian, Günther Prokop, Matthias Lehmann e Linda Dziuba-Kaiser. Use Information You Have Never Observed Together: Data Fusion as a Major Step Towards Realistic Test Scenarios. TU Dresden, 2020. http://dx.doi.org/10.26128/2024.3.

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Abstract (sommario):

Scenario-based testing is a major pillar in the development and effectiveness assessment of automated driving systems. Thereby, test scenarios address different information layers and situations (normal driving, critical situations and accidents) by using different databases. However, the systematic combination of accident and / or normal driving databases into new synthetic databases can help to obtain scenarios that are as realistic as possible. This paper shows how statistical matching (SM) can be applied to fuse different categorical accident and traffic observation databases. Hereby, the fusion is demonstrated in two use cases, each featuring several fusion methods. In use case 1, a synthetic database was generated out of two accident data samples, whereby 78.7% of the original values could be estimated correctly by a random forest classifier. The same fusion using distance-hot-deck reproduced only 67% of the original values, but better preserved the marginal distributions. A real-world application is illustrated in use case 2, where accident data was fused with over 23,000 car trajectories at one intersection in Germany. We could show that SM is applicable to fuse categorical traffic databases. In future research, the combination of hotdeck- methods and machine learning classifiers needs to be further investigated.

Wang, Shenlong, e David Forsyth. Safely Test Autonomous Vehicles with Augmented Reality. Illinois Center for Transportation, agosto 2022. http://dx.doi.org/10.36501/0197-9191/22-015.

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This work exploits augmented reality to safely train and validate autonomous vehicles’ performance in the real world under safety-critical scenarios. Toward this goal, we first develop algorithms that create virtual traffic participants with risky behaviors and seamlessly insert the virtual events into real images perceived from the physical world. The resulting composed images are photorealistic and physically grounded. The manipulated images are fed into the autonomous vehicle during testing, allowing the self-driving vehicle to react to such virtual events within either a photorealistic simulator or a real-world test track and real hardware systems. Our presented technique allows us to develop safe, hardware-in-the-loop, and cost-effective tests for self-driving cars to respond to immersive safety-critical traffic scenarios.

Desjardins e Sahney. PR-351-083602-R01 Field Demonstration of Reliability Based Guidelines for Pipeline Integrity. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), febbraio 2011. http://dx.doi.org/10.55274/r0010786.

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Abstract (sommario):

An in-depth review of the reliability framework developed by C-FER for PRCI (PR-244-05302 Guidelines for Reliability Based Pipeline Integrity Methods) was undertaken in Phase I of this project. In Phase II of this project, the guidelines were applied to a second set of inline inspection data � along with more specifically defined input parameters. Specifically, two scenarios were assessed for the corrosion data set: one scenario consisted of corrosion growth rate applied on a defect-specific basis whereas the second scenario consisted for corrosion growth rate applied on a segment-specific basis. The analysis was intended to test the method for repeatability of results as well as the sensitivity to one of the critical assumptions associated with corrosion growth rate. The results are presented in this report.