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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Decision theory to support evacuation in advance of catastrophic disaster including modular influence diagrams and spatial data analysis

Kailiponi, Paul January 2012 (has links)
Catastrophic disaster represents a vital issue in emergency management for many countries in the European Union (EU) and around the world. Given the damage to human lives that different hazards represent, evacuation operations can be the only option available to emergency managers to mitigate the loss of life from catastrophic disaster. However, due to the amount of time needed to effectively evacuate a large area, the decision to evacuate must occur when there is a relatively low probability of the event. An explicit understanding of the evacuation decision can lead to better organisational preparedness in advance of catastrophic disaster events. This research represents work performed with 159 emergency experts and professionals across ten countries. The goal of this research was to create decision-making aids for evacuations in advance of a variety of catastrophic disaster scenarios. Traditional Decision Theory (DT) provides a rational approach to decision-making that emphasizes the optimization of subjective preferences combined with uncertainty. Within evacuation decision-making, DT and its respective outputs are appealing; however the analytical process can be difficult due to the lack of observed data to support quantitative assessments from catastrophic events and relative infrequency of evacuation operations. This research explored the traditional use of DT applied to catastrophic evacuation scenarios. Theoretical contributions to DT and emergency management include: 1) identification of evacuation decision criteria, 2) inter-model analysis between decision structures called Influence Diagrams (IDs), 3) complete application of quantitative decision analysis to support evacuation decision-making and 4) multi-criteria analysis for evacuation vulnerability using spatial data. Important contributions from this work include:1) An analysis of evacuation criteria for a variety of catastrophic disaster scenarios2) Inter-model analysis of evacuation scenarios (flooding, nuclear dispersion and terrorist attack) to identify common probabilistic structures to support multi-hazard strategy planning3) Quantitative decision models to support evacuation strategies, identify key uncertainties and policy analysis 4) Process to use spatial data to support multi-criteria evacuation vulnerability analysis 5) Organisational self-assessment for evacuation decision-making and spatial data use based on findings across all participating countries.
2

A Framework for Integrating Influence Diagrams and POMDPs

Shi, Jinchuan 04 May 2018 (has links)
An influence diagram is a widely-used graphical model for representing and solving problems of sequential decision making under imperfect information. A closely-related model for the same class of problems is a partially observable Markov decision process (POMDP). This dissertation leverages the relationship between these two models to develop improved algorithms for solving influence diagrams. The primary contribution is to generalize two classic dynamic programming algorithms for solving influence diagrams, Arc Reversal and Variable Elimination, by integrating them with a dynamic programming technique originally developed for solving POMDPs. This generalization relaxes constraints on the ordering of the steps of these algorithms in a way that dramatically improves scalability, especially in solving complex, multi-stage decision problems. A secondary contribution is the adoption of a more compact and intuitive representation of the solution of an influence diagram, called a strategy. Instead of representing a strategy as a table or as a tree, a strategy is represented as an acyclic graph, which can be exponentially more compact, making the strategy easier to interpret and understand.
3

Quantitative risk analysis : Ship security analysis for effective risk control options

Liwång, Hans, Ringsberg, Jonas W., Norsell, Martin January 2013 (has links)
This study reviews ship security assessment. The objectives are to explore the possibilities for quantifying and performing a more thorough ship security risk analysis than that described in the International Ship and Port Facility Security code and to evaluate to what extent this more detailed analysis increases ship security and facilitate the effective selection of risk control options. The study focuses on Somali-based maritime piracy, using piracy on the Indian Ocean as a case study. Data are collected using questionnaires and interviews with civilian and military security experts who possess firsthand experience of piracy off the coast of Somalia. The data are collected specifically for this study and describe and quantify the threat’s capability, intent and likelihood of exploiting a ship’s vulnerability. Based on the collected description of the threat, the study analyzes and describes: probability of detection by pirates, probability of successful approach, and probability of successful boarding. The performed work shows good agreement between calculated probabilities and frequencies in the cited incident reports. Also, the developed scenarios describe the most important influences on the analyzed areas. The research therefore shows that the proposed risk-based approach, which uses structurally collected and documented information on the threat, can increase ship security by assisting in selecting risk control options. The approach also allows for a better understanding of the causal relationship between threat and risk than that provided in today’s security analysis by ship owners, for example. This understanding is crucial to choosing effective and robust risk control options.
4

Systems methodology for Analysis of Airborne Electronic Warfare Systems / Systemmetodik för analys av luftburna elektroniska krigföringssystem

Hedén, Hugo January 2021 (has links)
This report is one of the first to examine how system methodology can be applied as a tool to facilitate a holistic view of fighter aircraft survivability. This is done through the application of a modified version of multi-agent influence diagrams (MAIDs), as an analytical tool of two generic one-on-one scenarios based on Robert E. Balls The Fundamentals of Aircraft Combat Survivability, Analysis and Design. The concept of survivability has been limited to susceptibility because this is where ECM, ECCM and ESM operate. The result: three influence diagrams for each scenario and a generic MAID developed for the first scenario. These should not be seen as an exact technical description of the interaction between threats and countermeasures, but as a pilot application of system methodology within the study area. Furthermore, the user validation indicates that the diagrams can convey the complexity of the interactions between threats and countermeasures through a graphical presentation. The diagrams led to a deeper discussion about which influences are important for survival. The conclusion is that MAID and systems methodology can serve as a tool to describe and help communicate the complex relationships between elements and influences that affect the aircraft's survivability between different actors, provided they are modelled correctly. / Denna rapport är en av de första som undersöker hur systemmetodik kan tillämpas som ett verktyg för att underlätta en holistisk syn på stridsflygplans överlevnadsförmåga. Detta görs genom tillämpningen av en modifierad version av multiagent influence diagrams (MAIDs) som ett analysverktyg av två generiska en-mot-en-scenarier baserade på Robert E. Balls The Fundamentals of Aircraft Combat Survivability, Analysis and Design. Begreppet överlevnadsförmåga har avgränsats till mottaglighet eftersom det är här ECM, ECCM och ESM verkar. Resultatet: tre influensdiagram för varje scenario och ett generisk MAID baserat på det första scenariot. Dessa ska inte ses som en exakt teknisk beskrivning av interaktionen mellan hot och motmedel, utan som en pilottillämpning av systemmetodik inom studieområdet. Vidare indikerar användarvalideringen att diagrammen kan förmedla komplexiteten i interaktionerna mellan hot och motmedel genom en grafisk presentation. Diagrammen ledde till en djupare diskussion om vilka influenser som är av vikt för överlevnad. Slutsatsen är att MAID och systemmetodik kan fungera som ett verktyg för att beskriva och hjälpa till att kommunicera de komplexa sambanden mellan element och influenser som påverkar flygplanens överlevnadsförmåga mellan olika aktörer. En förutsättning är dock att de modelleras på ett korrekt sätt.
5

The dual credit teaching experience on high school and college campuses from the perspective of community college faculty

Hinds, David Meade 06 July 2012 (has links)
Hundreds of thousands of students earn credit toward both high school and college each year through dual credit programs. This research project used qualitative methods to elicit the story, the shared reality, of faculty who spend their time with these students. It is an important story to tell as legislators, community college and public school administrators, parents, and students are motivated to see these programs not only continue, but grow. System influence diagrams (SIDs) depicting the dual credit teaching experience on high school and college campuses were developed for two separate groups of community college faculty. The models were used for comparing the high school and college dual credit teaching environments. The results of this study support other research, suggesting there are important differences between the high school and college environments when teaching dual credit students. From an overall perspective, faculty found the community college campus environment superior to teaching on the high school campus for reasons related to facilities and technology, a sense of belonging in the larger organization, and the integration of dual credit students into a more traditional college environment. / text
6

Modeling Air Combat with Influence Diagrams

Bergdahl, Christopher January 2013 (has links)
Air combat is a complex situation, training for it and analysis of possible tactics are time consuming and expensive. In order to circumvent those problems, mathematical models of air combat can be used. This thesis presents air combat as a one-on-one influence diagram game where the influence diagram allows the dynamics of the aircraft, the preferences of the pilots and the uncertainty of decision making in a structural and transparent way to be taken into account. To obtain the players’ game optimal control sequence with respect to their preferences, the influence diagram has to be solved. This is done by truncating the diagram with a moving horizon technique and determining and implementing the optimal controls for a dynamic game which only lasts a few time steps. The result is a working air combat model, where a player estimates the probability that it resides in any of four possible states. The pilot’s preferences are modeled by utility functions, one for each possible state. In each time step, the players are maximizing the cumulative sum of the utilities for each state which each possible action gives. These are weighted with the corresponding probabilities. The model is demonstrated and evaluated in a few interesting aspects. The presented model offers a way of analyzing air combat tactics and maneuvering as well as a way of making autonomous decisions in for example air combat simulators.
7

The contribution of the teaching-learning environment to the development of self-regulation in learning

Mahlangu, Peter Patrick 29 May 2008 (has links)
This study focuses in the students’ perception of self-regulation in learning as influenced by the teaching-learning-environment. The study was conducted at the University of Pretoria. The participants in the study were first year students registered for a second semester module in Educational Psychology in the faculty of education. The size of the sample was nine (22,5%) male students and 31 (77,5%) female students. At the time of participation, the participants had attended university for a period of at least six months and had written tests and one examination. The Interactive Qualitative Analysis (IQA) method as described by Northcutt and McCoy (2004) was used to elicit participants’ knowledge and experiences of the research phenomenon. The participants were expected to complete an instrument that required them to indicate the direction of three relationships between all combinations of the themes which were selected on the basis of literature review. The participants were required to indicate how they perceive the nature of relationships between themes that were developed by the researcher as associated with self-regulated learning in a system of cause and effect. The main findings of the study indicate that language of instruction and student personality are primary drivers that determine the academic success of the students. The two themes exert great influence on other themes that are involved in the teaching-learning environment. Academic success emerged as primary outcome which means that it is a theme that depends to a large extent on how the other themes that exist in the teaching-learning environment are structured. The findings of the study indicate that there is no significant difference that exists in the male and female participants’ perception of the factors that influence self-regulation in learning. In both sample primary drivers were language of instruction and students’ personality and the primary outcome was academic success. / Dissertation (MEd (Educational Psychology))--University of Pretoria, 2008. / Educational Psychology / unrestricted
8

A qualitative study of the competencies that should be covered by a specialised undergraduate degree in risk management

De Swardt, Cecilia Jacoba 02 1900 (has links)
Purpose The purpose of the research was firstly, to determine the competencies required of risk managers and secondly, to consider the implications of such competencies in determining possible modules for inclusion in the design of a specialised undergraduate qualification in Risk Management. Methodology A qualitative research approach was followed, involving focus group interview sessions as part of an Interactive Qualitative Analysis (IQA) research study. Focus Group 1 comprised of academics teaching risk management at public universities in South Africa, and Focus Group 2 comprised of risk management practitioners in South Africa. Findings The competencies identified are business management and risk management knowledge; attributes such as assertiveness and courage; values such as ethics and integrity; as well as people, business and technical skills. Research implications The unique contribution of the current research was the innovative use of IQA for data collection, the removal of subjectivity and the rigour in analysing and presenting the results. The results are a starting point or foundation for the design of a specialised undergraduate degree in risk management that will both meet the requirements of the risk management profession and will equip learners with the best possible combination of knowledge, skills, attributes, values and attitudes to effectively manage risk in organisations. The implications for further research are that a study of the design, benchmarking and validation of a curriculum framework for a specialised undergraduate degree in risk management could be conducted. The development of a curriculum framework or curriculum did not form part of the scope of this study. / Okokuqala inhloso yocwaningo, ukuthola amakhono adingekayo kubaphathi bezinhlekelele kanti okwesibili, ukubheka imiphumela yalokho kusebenza ekunqumeni amamojuli angafakwa ekwakhiweni kweziqu ezikhethekile ezingakaphothulwa ngabafundi ku-Risk Management. Kwalandelwa indlela yocwaningo efanelekile, ebandakanya izikhathi zokuxoxisana zamaqembu njengengxenye yocwaningo lwe-Interactive Qualitative Analysis (IQA). I-Focus Group yoku-1 inabafundi abafundisa ukulawulwa kwezinhlekelele emanyuvesi vi kahulumeni aseNingizimu Afrika, kanye neFocus Group yesi-2 inabasebenzi bokulawulwa kobungozi eNingizimu Afrika. Amakhono ahlonziwe ukuphathwa kwebhizinisi nolwazi lokulawulwa kobungozi; anezimpawu ezinjengokuzethemba kanye nokuba nesibindi; ubugugu obufana nokuziphatha nobuqotho; kanye nabantu, amakhono ebhizinisi nezobuchwepheshe. / Die doel van die studie was eerstens om die bekwaamhede waaroor risikobestuurders moet beskik te bepaal, en tweedens, wat die implikasies van sodanige bekwaamhede inhou vir die modules vir insluiting in die ontwerp van ‘n gespesialiseerde voorgraadse kwalifikasie in Risikobestuur. Die studie het ‘n kwalitatiewe navorsingsbenadering gevolg deur gebruik te maak van fokusgroepsessies as deel van ‘n Interaktiewe Kwalitatiewe Ontleding (IKO) navorsingstudie. Fokusgroep 1 het bestaan uit akademici wat risikobestuur by openbare universiteite in Suid-Afrika doseer, en Fokusgroep 2 het uit risikobestuurpraktisyns in Suid-Afrika bestaan. Die bekwaamhede wat identifiseer is, is kennis van ondernemingsbestuur en risikobestuur; eienskappe soos selfgeldendheid en moed; waardes soos etiek en integriteit; asook mense, sake en tegniese vaardighede. / Finance, Risk Management and Banking / M. Com. (Risk Management)
9

An investigation into the integration of qualitative and quantitative techniques for addressing systemic complexity in the context of organisational strategic decision-making

McLucas, Alan Charles, Civil Engineering, Australian Defence Force Academy, UNSW January 2001 (has links)
System dynamics modelling has been used for around 40 years to address complex, systemic, dynamic problems, those often described as wicked. But, system dynamics modelling is not an exact science and arguments about the most suitable techniques to use in which circumstances, continues. The nature of these wicked problems is investigated through a series of case studies where poor situational awareness among stakeholders was identified. This was found to be an underlying cause for management failure, suggesting need for better ways of recognising and managing wicked problem situations. Human cognition is considered both as a limitation and enabler to decision-making in wicked problem environments. Naturalistic and deliberate decision-making are reviewed. The thesis identifies the need for integration of qualitative and quantitative techniques. Case study results and a review of the literature led to identification of a set of principles of method to be applied in an integrated framework, the aim being to develop an improved way of addressing wicked problems. These principles were applied to a series of cases in an action research setting. However, organisational and political barriers were encountered. This limited the exploitation and investigation of cases to varying degrees. In response to a need identified in the literature review and the case studies, a tool is designed to facilitate analysis of multi-factorial, non-linear causality. This unique tool and its use to assist in problem conceptualisation, and as an aid to testing alternate strategies, are demonstrated. Further investigation is needed in relation to the veracity of combining causal influences using this tool and system dynamics, broadly. System dynamics modelling was found to have utility needed to support analysis of wicked problems. However, failure in a particular modelling project occurred when it was found necessary to rely on human judgement in estimating values to be input into the models. This was found to be problematic and unacceptably risky for sponsors of the modelling effort. Finally, this work has also identified that further study is required into: the use of human judgement in decision-making and the validity of system dynamics models that rely on the quantification of human judgement.
10

An investigation into the integration of qualitative and quantitative techniques for addressing systemic complexity in the context of organisational strategic decision-making

McLucas, Alan Charles, Civil Engineering, Australian Defence Force Academy, UNSW January 2001 (has links)
System dynamics modelling has been used for around 40 years to address complex, systemic, dynamic problems, those often described as wicked. But, system dynamics modelling is not an exact science and arguments about the most suitable techniques to use in which circumstances, continues. The nature of these wicked problems is investigated through a series of case studies where poor situational awareness among stakeholders was identified. This was found to be an underlying cause for management failure, suggesting need for better ways of recognising and managing wicked problem situations. Human cognition is considered both as a limitation and enabler to decision-making in wicked problem environments. Naturalistic and deliberate decision-making are reviewed. The thesis identifies the need for integration of qualitative and quantitative techniques. Case study results and a review of the literature led to identification of a set of principles of method to be applied in an integrated framework, the aim being to develop an improved way of addressing wicked problems. These principles were applied to a series of cases in an action research setting. However, organisational and political barriers were encountered. This limited the exploitation and investigation of cases to varying degrees. In response to a need identified in the literature review and the case studies, a tool is designed to facilitate analysis of multi-factorial, non-linear causality. This unique tool and its use to assist in problem conceptualisation, and as an aid to testing alternate strategies, are demonstrated. Further investigation is needed in relation to the veracity of combining causal influences using this tool and system dynamics, broadly. System dynamics modelling was found to have utility needed to support analysis of wicked problems. However, failure in a particular modelling project occurred when it was found necessary to rely on human judgement in estimating values to be input into the models. This was found to be problematic and unacceptably risky for sponsors of the modelling effort. Finally, this work has also identified that further study is required into: the use of human judgement in decision-making and the validity of system dynamics models that rely on the quantification of human judgement.

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