Browsing by Subject "Decision analysis"

Now showing 1 - 7 of 7

Open Access
A MULTICRITERIA ANALYSIS OF THE CONSERVATION PLANNING TOOL OF THE NORTH CAROLINA NATURAL HERITAGE PROGRAM
(2012-04-26) Yeh, Sung-Kang
Land conservation and land use planning are the essential approaches in mitigating human disturbances and maintaining ecological functions. These approaches require identification and prioritization of different land characteristics to efficiently conserve the areas that represent significant biodiversity values. In North Carolina, the Conservation Planning Tool (CPT) was developed by the North Carolina National Heritage Program (NCNHP) to achieve this goal. However, the weighting method in CPT falls short in that it does not assign greater credit to areas with multiple values, and it ignores the biophysical characteristics that may contribute to the values of biodiversity. In order to critique the issues in CPT, I developed a rating tool based on Multi-Attribute Utility Theory (MAUT) analysis and incorporated biophysical measurements into the new habitat prioritization. I consulted Allison Weakley, the Conservation Planner of the North Carolina Natural Heritage Program, to assess the levels of preference and weights for each measurement, and used these results to calculate the final score. Because the methods of utility and weight assessment in the two systems are considerably different, I used qualitative criteria to compare the advantages and disadvantages of the two rating systems. The results show that the new rating tool is able to address the weighting problem in CPT, is less redundant in the selection of measurements, and offers more comprehensive data completeness. On the other hand, CPT is friendlier for tool users who may not be familiar with the technical details, more flexible in accommodating new measurements, and more comprehensive in evaluating both aquatic and terrestrial habitats. Land conservation and land use planning are the essential approaches in mitigating human disturbances and maintaining ecological functions. These approaches require identification and prioritization of different land characteristics to efficiently conserve the areas that represent significant biodiversity values. In North Carolina, the Conservation Planning Tool (CPT) was developed by the North Carolina National Heritage Program (NCNHP) to achieve this goal. However, the weighting method in CPT falls short in that it does not assign greater credit to areas with multiple values, and it ignores the biophysical characteristics that may contribute to the values of biodiversity. In order to critique the issues in CPT, I developed a rating tool based on Multi-Attribute Utility Theory (MAUT) analysis and incorporated biophysical measurements into the new habitat prioritization. I consulted Allison Weakley, the Conservation Planner of the North Carolina Natural Heritage Program, to assess the levels of preference and weights for each measurement, and used these results to calculate the final score. Because the methods of utility and weight assessment in the two systems are considerably different, I used qualitative criteria to compare the advantages and disadvantages of the two rating systems. The results show that the new rating tool is able to address the weighting problem in CPT, is less redundant in the selection of measurements, and offers more comprehensive data completeness. On the other hand, CPT is friendlier for tool users who may not be familiar with the technical details, more flexible in accommodating new measurements, and more comprehensive in evaluating both aquatic and terrestrial habitats.
Open Access
An Analysis of a Biomass-Fueled Combined Heat and Power Plant for a Colorado Homeowners Association
(2011-04-28) Thomas, Mikel T.
I evaluated available technologies and conflicting social, environmental and economic objectives important to a Colorado homeowners association (“the Ranch”) to determine if a combined heat and power (CHP) plant, fueled by woody biomass available on the Ranch, is worth pursuing at this time. The conflicting objectives were to maximize the economics of the CHP plant, minimize the aesthetic impacts of a power plant, minimize the impacts of traffic associated with hauling the biomass from the field to the power plant facility, and maximize the environmental objectives of wildfire risk reduction and carbon dioxide emissions reductions. I reviewed the literature for biomass-fueled CHP technologies that are reported to be commercially available at a scale of less than 35 kilowatts of electricity (limited by available biomass fuel). I performed an economic analysis on three of these technologies, comparing them to the status quo of continuing to purchase energy at retail prices over a 25 year time horizon. Using multiattribute utility analysis, I quantified the conflicting objectives important to the Ranch owners when comparing the single technology that had a positive payback against the status quo, assuming the technology would perform as predicted by the manufacturer. Because the technology is unproven, I then analyzed the effects of uncertainty about the longevity and annual operating capacity on the viability of using such a power facility using multiattribute utility analysis under uncertainty. My results indicated there is currently no basis to suggest pursuing a small scale biomass-fueled CHP plant on the Ranch. The placement of a CHP plant at the Ranch headquarters was too much of an aesthetic concern and the plant technology proved too unreliable to permit environmental benefits to outweigh these negative factors. Development of small scale biomass-fueled combined heat and power technology, so that it is reliable and affordable, will be crucial in the future for these technologies to play a role as an alternative energy strategy for the Ranch.
Open Access
Developing an alternative approach to wildlife management in the Duke Forest
(2017-04-25) Kramer, Renee; PalmerDwore, Hannah; Satin, Peter
Wildlife management is not currently a major priority of the Duke Forest, but staff have expressed an interest in making it a more significant aspect in future forest management decisions. We here used a multi-criteria decision analysis framework to explore a variety of wildlife management and monitoring alternatives with the aim of providing Duke Forest staff an adaptive tool for making well-informed wildlife management decisions. We identified potential management strategies by looking at forest management plans in use by peer institutions and then conducting a meta-analysis to determine the effect each of the potential strategies had on taxa of interest to Forest staff. We also looked at the possibility of using a community-based monitoring approach to supplement limited Forest staff resources through the use of expert interviews and a formal review of the literature, and assessed the importance of multiple components in ensuring quality data monitoring. We used the results of both of these analyses to construct a decision framework Duke Forest can use to identify wildlife management and monitoring schemes.
Open Access
Essays on Dynamic Tournaments
(2017) Wang, Ruoyu
This dissertation studies dynamic tournaments and their economic and managerial implications from two different perspectives. The first half focuses on the optimal timing of information release when a tournament uses a feedback scheme, while the other half investigates the impact of the use of mercy rule in a dynamic tournament on the economic output and other system wide characteristics.
In Chapter 2, we study dynamic tournaments in which time is modeled explicitly, as opposed to with the abstract notion of ``periods.'' By doing so, we characterize the effects of the ex-ante-designated timing of an interim progress report. Whether or not a policy of reporting increases total expected effort does not depend on the release time of the report, however the magnitude of the effect does. We demonstrate that total expected effort is single-peaked or single-troughed in the report's release time depending on parameters, with the peak/tough located at a time strictly more than halfway through the tournament. However, a policy of releasing information always harms the expected utility of the tournament's participants. Implications for tournament design are discussed.
Chaper 3 explores dynamic tournaments in a continuous space and continuous
time framework, in which contestants can observe their opponents' progresses
in real time and have the opportunity to end the contest early when one's
lead over the other is larger than some pre-determined threshold (a.k.a a
mercy rule). We first show that the game has a unique equilibrium, then characterize
the equilibrium numerically, and investigate the impacts of mercy rules on
tournament design. By doing so, we find that there exists an optimal mercy
rule that induces the best economic output, even though players always prefer a
tournament without a mercy rule. Depending on the cost and noises
parameters, a non-monotonic mercy rule may perform better. We also consider
the scenario in which players prefer to end the game early because of
outside options and have the choice to drop out. Given an exogenous mercy
rule, this drop-out option endogenizes another boundary. And surprisingly,
the endogenous mercy rule is not always dominated by the exogenous rule in
terms of inducing efforts.
Open Access
The Verification of Probabilistic Forecasts in Decision and Risk Analysis
(2009) Jose, Victor Richmond
Probability forecasts play an important role in many decision and risk analysis applications. Research and practice over the years have shown that the shift towards distributional forecasts provides a more accurate and appropriate means of capturing risk in models for these applications. This means that mathematical tools for analyzing the quality of these forecasts, may it come from experts, models or data, become important to the decision maker. In this regard, strictly proper scoring rules have been widely studied because of their ability to encourage assessors to provide truthful reports. This dissertation contributes to the scoring rule literature in two main areas of assessment - probability forecasts and quantile assessments.
In the area of probability assessment, scoring rules typically studied in the literature, and commonly used in practice, evaluate probability assessments relative to a default uniform measure. In many applications, the uniform baseline used to represent some notion of ignorance is inappropriate. In this dissertation, we generalize the power and pseudospherical family of scoring rules, two large parametric families of commonly-used scoring rules, by incorporating the notion of a non-uniform baseline distribution for both the discrete and continuous cases. With an appropriate normalization and choice of parameters, we show that these new families of scoring rules relate to various well-known divergence measures from information theory and to well-founded decision models when framed in an expected utility maximization context.
In applications where the probability space considered has an ordinal ranking between states, an important property often considered is sensitivity to distance. Scoring rules with this property provide higher scores to assessments that allocate higher probability mass to events “closer” to that which occurs based on some notion of distance. In this setting, we provide an approach that allows us to generate new sensitive to distance strictly proper scoring rules from well-known strictly proper binary scoring rules. Through the use of the weighted scoring rules, we also show that these new scores can incorporate a specified baseline distribution, in addition to being strictly proper and sensitive to distance.
In the inverse problem of quantile assessment, scoring rules have not yet been well-studied and well-developed. We examine the differences between scoring rules for probability and quantile assessments, and demonstrate why the tools that have been developed for probability assessments no longer encourage truthful reporting when used for quantile assessments. In addition, we shed light on new properties and characterizations for some of these rules that could guide decision makers trying to choosing an appropriate scoring rule.
Open Access
Timber Best Practice Guidelines for Protected Areas Management in Gabon
(2013-04-23) Winchester, Caroline
Located in Central Africa, Gabon contains large swaths of tropical forest that are a reserve for an incredible level of plant and animal biodiversity. In order to protect this biodiversity, in 2002 thirteen national parks were created along with buffer zones surrounding these parks. Since 2007 Gabon’s national park agency, L’Agence Nationale des Parcs Nationaux (ANPN), has been the regulatory body governing both the parks and their associated buffer zones. In recent years, Gabon’s rapidly expanding timber industry has threatened the integrity of these parks. Within buffer zones, timber operators are required to submit environmental impact assessments to ANPN and the Ministry of Environment to demonstrate that timber operations will not negatively impact neighboring parks. However, as of 2012 ANPN lacked guidelines for how timber operations should be conducted in park buffer zones, and thus lacked a mechanism by which to enforce or monitor timber operators for environmental compliance. To help resolve this challenge, I spent a total of thirteen weeks in Gabon as an intern with ANPN. I was assigned the task of developing best practice guideline recommendations for how timber operations should be conducted in national park buffer zones. I also incorporated a way to score companies for their compliance with these best practices. In order to create the timber best practice guidelines I assembled twelve international guidelines into one document, incorporated the priorities of ANPN, obtained feedback from forestry experts, and ensured the guidelines were realistic and context specific by working for five weeks with Olam Timber Gabon. I then created an associated compliance scoring template (CST) utilizing the theory of decision analysis and the method of swing weighting. With the timber best practice guidelines and associated CST, ANPN is closer to being able to enforce good practices adjacent to national parks. They now have the ability to clearly state what they expect of timber operators in buffer zones, and they have a method to monitor operators for compliance. Given the negative impacts timber operations can have on ecosystems, the implementation of the guidelines will help ensure that Gabon’s national parks remain intact for years to come.
Open Access
Which Nutrient Criteria Should States and Tribes Choose to Determine Waterbody Impairment?: Using Science and Judgments to Inform Decision-making
(2007-12-12) Kenney, Melissa A
Nutrients are the number one water pollution problem for U.S. lakes, reservoirs, and ponds. Excessive nutrients, such as nitrogen and phosphorus, lead to eutrophication, a condition that can include low oxygen levels, noxious algal blooms, and fish kills. Since eutrophication is a condition that manifests itself differently in different systems, there is not a criterion variable with a clear threshold that can be used to set the criterion level. This dissertation presents an approach to address the question: How should States and Tribes choose nutrient criteria to determine eutrophication-related impairments of the designated use? To address this question I used a combination of water quality modeling and decision analysis to determine the optimal nutrient criterion variables and levels. To choose criterion variables that are predictive of the designated use, I utilized statistical models (structural equation models, multiple regression, and binomial regression model) to link the measured water quality variables to expert elicited categories of eutrophication and the designated uses. These models were applied successfully to single waterbodies, the Kissimmee Chain-of-Lakes region, and the State of North Carolina to assess which candidate criterion variables were the most predictive. Additionally, the models indicated that the variables that were most predictive of eutrophication were also the most predictive of the designated use. Using the predictive nutrient criteria variables, I applied a decision-analytic approach to nutrient criteria setting in North Carolina. I developed a nutrient criteria value model that included two submodels, a water quality model and a multiattribute value model. The submodels were parameterized using a combination of water quality data, expert elicitation data, and utility assessments. The outcome of the nutrient criteria value model is the overall expected value for a criterion level choice; the optimal criterion level would be the choice that maximized the expected value. Using the preferences of North Carolina environmental decision-makers and a total phosphorus criterion variable, the optimal criterion level was between 0.03 mg/L and 0.07 mg/L. Ultimately, I hope this research will establish methodology used to set appropriate water quality criteria.