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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

Choice of treatment: Application of decision analysis

Yin, Xi Peng January 1994 (has links)
No description available.
2

Value of information and portfolio decision analysis

Zan, Kun 25 September 2013 (has links)
Value of information (VOI) is the amount a decision maker is willing to pay for information to better understand the uncertainty surrounding a decision, prior to making the decision. VOI is a key part of decision analysis (DA). Especially in this age of information explosion, evaluating information value is critical. VOI research tries to derive generic conclusions regarding VOI properties. However, in most cases, VOI properties rely on the specific decision context, which means that VOI properties may not be generalizable. Thus, instead, VOI properties have been derived for typical or representative decisions. In addition, VOI analysis as a method of DA has been successfully applied to practical decision problems in a variety of industries. This approach has also been adopted as the basis of a heuristic algorithm in the latest research in simulation and optimization. Portfolio Decision Analysis (PDA), rooted in DA, is a body of theories, methods, and practices that seek to help decision makers with limited budget select a subset of candidate items through mathematical modeling that accounts for relevant constraints, preferences, and uncertainties. As one of the main tools for resource allocation problems, its successful implementation, especially in capital-intensive industries such as pharmaceuticals and oil & gas, has been documented (Salo, Keisler and Morton 2011). Although VOI and PDA have been extensively researched separately, their combination has received attention only recently. Resource allocation problems are ubiquitous. Although significant attention has been directed at it, less energy has been focused on understanding the VOI within this setting, and the role of VOI analysis to solve resource allocation problems. This belief motivates the present work. We investigate VOI properties in portfolio contexts that can be modeled as a knapsack problem. By further looking at the properties, we illustrate how VOI analysis can derive portfolio management insights to facilitate PDA process. We also develop a method to evaluate the VOI of information portfolios and how the VOI will be affected by the correlations between information sources. Last, we investigate the performance of a widely implemented portfolio selection approach, the benefit-cost ratio (BCR) approach, in PDA practice. / text
3

Belief and decision aiding

Freeling, A. N. S. January 1983 (has links)
No description available.
4

A unified framework for indeterminate probabilities and utilities /

Ekenberg, Love, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Univ., 2005. / Härtill 6 uppsatser.
5

Use of multiple criteria decision analysis for the development of adaptive fishery management strategies : the case of the Danube Delta Biosphere Reserve

Kravatzky, Axel January 2001 (has links)
Fishery managers face two problems that are endemic to all renewable resource management: how much of the resource should be extracted, and how should resource users be managed to ensure efficiency and fairness. The predominant fishery management approach addresses these problems through fish stock assessment and resource economics. However, my review of the literature and analysis of the situation in the Danube Delta Biosphere Reserve show that both methodologies face serious difficulties: they deal inadequately with uncertainties about the causes of observed behaviour and the likely effects of different policies; they are too focused on readily measurable objectives; and they do not address the effects of the institutional context on management. In Chapter 3, I examine previous applications of Multiple Criteria Decision Analysis (MCDA) with a view to see if they can be applied to fishery management. My analysis shows that until now MCDA has been used to address only the first two sets of fishery management problems: systematically incorporating uncertainty and multiple objectives into policy development. I also argue that existing proposals for the use of Decision Analysis can be classified as variations of one version of MCDA, namely Multiple Stakeholder Decision Analysis (MSDA). The main problems that remain to be resolved relate to the interaction between experts, stakeholders, and managers when there are conflicting interpretations of evidence, and situations of high institutional inertia. In Chapter 4, I examine these problems within the context of ecological management experience and New Institutional Economics. I argue that for complex problems, such as those in the Danube Delta, management that aims to attain narrowly defined optimal fishing yields through command and control measures is unfeasable and undesirable. A more promising approach would seek to strengthen resilience, promote organisational variety, and increase the leverage of stakeholders over those who provide services for them. When one seeks to achieve such a transformation of management, I argue that the intervention needs to take into account the specific institutional circumstances of the client. In Chapter 5, I show how management procedures, problem perception, and strategy development are influenced by organisational structure and the hierarchical position of managers. That is why decision analysis interventions must address both technical as well as institutional needs of clients. In Chapter 6, I discuss Decision Conferencing, an alternative MCDA approach, and argue that it is more suitable for dealing with management problems such as those of the Danube Delta Biosphere Reserve. Decision Conferences can provide a structure for expert, manager, and stakeholder interaction and can lead to the transformation of social realities. In Chapters 7 and 8, I review the context and concrete environmental and institutional problems that led to the first Decision Conference on an environmental management problem. I report the processes of the Decision Conference, the agreements reached, and anlyse both the short and medium term effects of the intervention. On the basis of that evidence I make claims about the general utility of the approach. The thesis concludes with proposals to improve Decision Conferencing through a framework that provides guidance for context specific process management and helps to ensure that a requisite variety of viewpoints are incorporated into management strategy development.
6

Approaches to modelling in decision-analytic health economic evaluations: Factors to differentiate between approaches

Tsoi, Bernice 11 1900 (has links)
BACKGROUND & OBJECTIVES Decision-analytic modelling can inform healthcare resource allocation and reimbursement decision-making, with modelling approaches adapted from a variety of disciplines. The objective of this thesis was to investigate the evidence surrounding when each approach should be used when conducting health economic evaluations. METHODS Project 1: A systematic review identified selection criteria, referred to as factors, through an evaluation of existing decision frameworks that aimed to differentiate between models. Project 2: Employing the factors identified from Project 1, a systematic review explored the extent to which empirical cross-validation studies agree on the importance of each on its impact to model selection. Project 3: A decision tree evaluating the cost-effectiveness of two vaccination strategies in children was reconstructed as system dynamics and agent-based models and compared. Scenario analyses assessed the situations whereby the model’s results would be sensitive to or be better handled by a particular approach. RESULTS Project 1: Among the eight frameworks identified; each involved a different set of structural or practical factors. Disagreements emerged between frameworks in the classification of the structural features specific to each modelling approach. Project 2: Nine exercises have been conducted, mostly focused on the criteria of interactivity (i.e., static vs. dynamic) and population resolution (i.e., aggregate vs. individual). Aggregate- and individual-level models were found to produce similar results with a practical trade-off between validity and feasibility. In the presence of large indirect effects, dynamic and static models often produced disparate results. Project 3: When calibrated, all three approaches reached consistent findings. Adaptation away from base-case assumptions led to different quantitative results on which vaccination strategy would be most optimal. CONCLUSION Despite disagreement among the frameworks on how to recommend modelling approaches, consistent conclusions were observed in empirical cross-validation studies. More empirical evidence is therefore needed to improve one’s understanding of the impact of the remaining factors on model selection. / Dissertation / Doctor of Philosophy (PhD)
7

The development of an approach and decision support tool to inform sustainable roof selection

Hampshire, Philip January 2015 (has links)
Despite the importance of roofs, improved roof selection has not been explored in significant depth. Therefore this research explores the possibilities that roofs offer to improve the value and sustainability of buildings. It is concerned with the roof as a system, explicitly connected with the building and their impacts on wider society. This research, develops and tests techniques to better understand what constitutes value and sustainability for a building project’s context through action research. The sustainability and value themes output through the use of such techniques are then considered as a basis for the selection of roof attributes through Keeney’s value focused thinking approach. Once the roof performance attributes have been established, designers and clients then require quantitative data to decide which roof type represents the highest value / most sustainable option. Thus the research also collates and maps peer reviewed quantitative performance data on the performance of roofing systems in relation to climate type as well as providing information from leading modelling packages for different roof options. An approach for selecting the most appropriate data is then developed. This allows the practitioner to be able to access reliable peer reviewed information and utilise leading modelling techniques to quickly gain information regarding the performance of various roof systems for use in the project context. An approach is developed to bring this information together with the important sustainability considerations for the project to inform sustainable roof selection. This combines the different types of roof performance with the relevant decision attributes early in the design process, to provide insight into which roof option represents the best overall economic, environmental and social value and therefore the most sustainable roof option. The primary contribution to knowledge presented in this thesis is the development of a pragmatic realist approach to sustainable roof selection.
8

Decision Aid for Planning Local Energy Systems : Application of Multi-Criteria Decision Analysis

Catrinu, Maria January 2006 (has links)
<p>Planning is what sustains an energy system. It is a process of analysis and ongoing decision making about what resources and energy technologies to use when supplying energy to society. This research focuses on integrated energy systems, i.e. systems that are comprised of several energy carriers – electricity, gas, hot water - and energy distribution networks. The planning of these kinds of systems is a complex process, influenced by many factors, among which the most important are the availability of energy resources and the competition between different energy carriers in satisfying energy demand. During the last 10-20 years significant changes have taken place on the world energy scene, which have important implications for energy planning. Two main factors have triggered these changes. The first factor is the immediate need to address environmental changes or more generally, to take measures that are sustainable in the long run. Sustainability can be defined in many ways and in relation to different issues such as economic and ecologic development, reduction of greenhouse gases, responsible use of natural resources, social equity, etc. In recent years, an increased awareness of these issues has been observed at all levels of the society. The second factor is the deregulation of national energy sectors in more than 50 countries. This process brought changes in the ownership of different parts of the formerly integrated energy systems. New business opportunities were created in power generation, wholesale power/gas trading and energy retailing, while the energy infrastructures remained state owned or/and under regulatory control. The newly created energy markets (many of them international) have attracted both new players (power, oil and gas companies and financial institutions) together with the old ones (integrated utilities). In parallel with this vertical separation of national energy sectors, recent studies have shown a tendency for horizontal integration at the regional/company level. For instance, in order to reduce their overall business risk, companies prefer to participate in several segments of the energy value chain (in both regulated and non-regulated activities), and often across more than one fuel commodity, such as gas and electricity or district heating. In this context, the competition between different energy carriers in satisfying the end-use energy demand became obvious in economic as well as in technological and environmental terms. Traditionally, in integrated planning, this competition did not play a big role, since the same state entity made decisions at both national and regional levels. However, in the post-deregulation era it is no longer obvious who the planner is. In many cases, planning decision at local levels involve at least three main interest groups: energy companies (and/or other investors), the state and the local community. This thesis is motivated by the need to help planners to cope with the changes in concepts and values concerning the planning of local energy supply systems. This thesis has two aims. The first aim is to improve the understanding of what planning of local systems implies and how such a process can be structured. The second aim is to contribute to the development of decision support methodologies and tools that can cope with the needs in planning. For this purpose, the use of energy modelling and Multi- Criteria Decision Analysis has been studied.</p>
9

A Prescriptive Approach to Eliciting Decision Information

Riabacke, Mona January 2012 (has links)
The amount of information involved in many decision making situations has increased dramatically in recent years and support of some kind is often needed. Consequently, fields like Business Intelligence (BI) and Decision Support Systems (DSS) have advanced. Decision analysis applications belong to the latter category and aim to support decision making activities in businesses and organizations, and provide more clearly structured decision material to use as a basis for decisions. In spite of a belief in their potential, their employment is still limited in practice, which could partly be attributed to the fact that they are incomplete to support decision processes sufficiently in real settings. At present, e.g., the specification and execution of the elicitation of input data is often left to the discretion of the user. Yet, this involves quite a few problematic elements and is of importance for the quality of the process as a whole. This thesis focuses on more practically useful elicitation of information in decision analysis applications than what is offered today. A process model emphasizing the importance of structured elicitation of adequate input data throughout decision processes is also suggested. In order to further define the problematic aspects of elicitation, three empirical studies were conducted. The problems with eliciting precise decision data suggests that using imprecise values within elicitation is a more realistic and useful approach to strive for. Based on theory and the findings of the studies, a weight elicitation method for imprecise statements and noisy input was formalized into the Cardinal Rank Ordering of Criteria (CROC) method. This method is both compatible with an adapted prescriptive decision making model, focused on a more structured elicitation component, as well as algorithms for dealing with such data. The CROC method was employed and validated in two real-life cases, which is not so common within decision analysis research. / Mängden information i många beslutssituationer har ökat markant under senare år och det finns ofta behov av någon form av stöd. Följaktligen har områden som Business Intelligence (BI) och Beslutsstödssystem (BSS) avancerat. Beslutsanalysverktyg tillhör den senare kategorin och syftar till att fungera som stöd vid beslutsfattande inom företag och organisationer och tillhandahålla mer strukturerat underlag för beslut. Trots en tro på deras potential, så är deras användande begränsat i praktiken, vilket delvis kan tillskrivas det faktum att de är inkompletta för att stödja beslutsprocesser i tillräcklig utsträckning i verkligheten. För närvarande förutsätts, t.ex. ofta att användaren själv klarar av att specificera och utföra utvinningen (eliciteringen) av input data. Detta involverar dock ett antal problematiska delar och dess kvalité är av vikt för hela processen. Denna avhandling fokuserar på mer praktiskt användbar elicitering av information i beslutsanalys-applikationer än vad som finns att tillgå idag. En processmodell som betonar vikten av strukturerad elicitering av adekvata indata genom hela beslutsprocessen föreslås också. För att ytterligare definiera de problematiska aspekterna av elicitering utfördes tre empiriska studier. Problemen med att utvinna precisa beslutsdata antyder att användandet av oprecisa värden inom elicitering är en mer realistisk och användbar ansats att sträva efter. Baserat på teori och resultaten av studierna formaliserades en vikteliciterings-metod för oprecisa utlåtanden och osäkra indata i Cardinal Rank Ordering of Criteria (CROC) metoden. Metoden är både kompatibel med en anpassad preskriptiv beslutsmodell fokuserad på en mer strukturerad eliciteringskomponent samt algoritmer för att hantera denna typ av data. CROC-metoden användes och validerades i två riktiga fall, vilket inte är så vanligt inom beslutsanalys forskning. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Accepted. Paper 7: Submitted. </p>
10

Decision Aid for Planning Local Energy Systems : Application of Multi-Criteria Decision Analysis

Catrinu, Maria January 2006 (has links)
Planning is what sustains an energy system. It is a process of analysis and ongoing decision making about what resources and energy technologies to use when supplying energy to society. This research focuses on integrated energy systems, i.e. systems that are comprised of several energy carriers – electricity, gas, hot water - and energy distribution networks. The planning of these kinds of systems is a complex process, influenced by many factors, among which the most important are the availability of energy resources and the competition between different energy carriers in satisfying energy demand. During the last 10-20 years significant changes have taken place on the world energy scene, which have important implications for energy planning. Two main factors have triggered these changes. The first factor is the immediate need to address environmental changes or more generally, to take measures that are sustainable in the long run. Sustainability can be defined in many ways and in relation to different issues such as economic and ecologic development, reduction of greenhouse gases, responsible use of natural resources, social equity, etc. In recent years, an increased awareness of these issues has been observed at all levels of the society. The second factor is the deregulation of national energy sectors in more than 50 countries. This process brought changes in the ownership of different parts of the formerly integrated energy systems. New business opportunities were created in power generation, wholesale power/gas trading and energy retailing, while the energy infrastructures remained state owned or/and under regulatory control. The newly created energy markets (many of them international) have attracted both new players (power, oil and gas companies and financial institutions) together with the old ones (integrated utilities). In parallel with this vertical separation of national energy sectors, recent studies have shown a tendency for horizontal integration at the regional/company level. For instance, in order to reduce their overall business risk, companies prefer to participate in several segments of the energy value chain (in both regulated and non-regulated activities), and often across more than one fuel commodity, such as gas and electricity or district heating. In this context, the competition between different energy carriers in satisfying the end-use energy demand became obvious in economic as well as in technological and environmental terms. Traditionally, in integrated planning, this competition did not play a big role, since the same state entity made decisions at both national and regional levels. However, in the post-deregulation era it is no longer obvious who the planner is. In many cases, planning decision at local levels involve at least three main interest groups: energy companies (and/or other investors), the state and the local community. This thesis is motivated by the need to help planners to cope with the changes in concepts and values concerning the planning of local energy supply systems. This thesis has two aims. The first aim is to improve the understanding of what planning of local systems implies and how such a process can be structured. The second aim is to contribute to the development of decision support methodologies and tools that can cope with the needs in planning. For this purpose, the use of energy modelling and Multi- Criteria Decision Analysis has been studied.

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