Due to a variety of political, economic, and technological factors, many national electricity industries around the globe are transforming from non-competitive monopolies with centralized systems to decentralized operations with competitive business units. This process, commonly referred to as deregulation (or liberalization) is driven by the belief that a monopolistic industry fails to achieve economic efficiency for consumers over the long run. Deregulation has occurred in a number of industries such as: aviation, natural gas, transportation, and telecommunications. The most recent movement involving the deregulation of the electricity marketplace is expected to yield consumer benefit as well. To facilitate deregulation of the electricity marketplace, competitive business units must be established to manage various functions and services independently. In addition, these business units must be given physical property rights for certain parts of the transmission and distribution network in order to provide reliable service and make effective business decisions. However, partitioning a physical power grid into economically viable districts involves many considerations. We refer to this complex problem as the electrical power districting problem. This research is intended to identify the necessary and fundamental characteristics to appropriately model and solve an electrical power districting problem. Specifically, the objectives of this research are five-fold. First, to identify the issues relevant to electrical power districting problems. Second, to investigate the similarities and differences of electrical power districting problems with other districting problems published in the research literature. Third, to develop and recommend an appropriate solution methodology for electrical power districting problems. Fourth, to demonstrate the effectiveness of the proposed solution method for a specific case of electric power districting in the Republic of Ghana, with data provided by the World Bank. Finally, to develop a decision support system for the decision makers at the World Bank for solving Ghana's electrical power districting problem. / Ph. D.

The presence of silt and clay particles has long been thought to affect the behavior of a sand under cyclic loading. Unfortunately, a review of studies published in the literature reveals that no clear conclusions can be drawn as to how altering fines content and plasticity actually affects the liquefaction resistance of a sand. In fact, the literature contains what appears to be contradictory evidence. There is a need to clarify the effects of fines content and plasticity on the liquefaction resistance of sandy soils, and to determine methods for accounting for these effects in engineering practice. In order to help answer these questions, a program of research in the form of a laboratory parametric study intended to clarify the effects which varying fines content and plasticity have upon the liquefaction resistance of sandy sands was undertaken. The program of research consisted of a large number of cyclic triaxial tests performed on two sands with varying quantities of plastic and non-plastic fines. The program of research also examined the applicability of plasticity based liquefaction criteria and the effects of fines content and plasticity on pore pressure generation. Lastly, a review of how the findings of this study may affect the manner in which simplified analyses are performed in engineering practice was made. The results of the study performed are used to clarify the effects of non-plastic fines content and resolve the majority of the inconsistencies in the literature. The effects of plastic fines content and fines plasticity are shown to be different than has been previously reported. The validity of plasticity based liquefaction criteria is established, the mechanism responsible for their validity is explained, and a new simplified criteria proposed. The effects of fines content and plasticity on pore pressure generation are discussed, and several recommendations are made for implementing the findings of this study into engineering practice. / Ph. D.

An expert system approach to help OR naive users formulate and solve goal programs is proposed. The approach is demonstrated for single product blending problems using VP-Expert as the developmental tool. Results of a study using undergraduate and graduate business students to test the expert system effectiveness are provided. An expert system determines the problem type using a taxonomy based upon problem context. Each problem type possesses distinct characteristics. Characteristics of twenty-four different problem types are discussed. Formulation of constraints using problem characteristics is demonstrated. The expert system uses constraint information to assist users in goal selection. Goal structures are constructed using a pairwise comparison technique. Solution values, recommendations based upon sensitivity analysis, and trade-offs between conflicting goals are provided to the user. A feedback loop permitting model changes and reiteration of solution and recommendation steps is provided. / Ph. D.

With a new focus on flow regulation by the Tennessee Valley Authority (TVA) in reservoir tailwaters, it is now possible to recover many mussel species that once occurred in these reaches. Before flows can be modified to create habitat for freshwater mussels, suitable microhabitat conditions must be defined. In this study, I used multiple approaches to define suitable microhabitats for species in the free-flowing upper Clinch River, Virginia and Tennessee, where reproducing mussel populations persist. During summer low flows in 2003 and 2004, I measured flow and substrate conditions in over 1000 microhabitat patches (0.25 m² quadrat samples) across five river reaches. Flow characteristics and embeddedness were significantly different between microhabitats occupied and unoccupied by the most abundant species (MRPP, p < 0.05). Comparison of simple and multiple logistic regression models with Akaike's Information Criteria (AIC) demonstrated that increasing Fleisswasserstammtisch (FST) hemisphere number (a measure of shear stress), decreasing degree of embeddedness, and increasing mean column velocity best explained species occurrences in a microhabitat patch. Subtle differentiation in habitat use among species was observed; however, most species appeared to be microhabitat generalists. Species were grouped into three habitat guilds using corresponding canonical analysis and cluster analysis: fast-flow specialists (FFS), fast-flow generalists (FFG), and slow-flow tolerant (SFT). I used the same data set to develop and test transferability of Habitat Suitability Criteria (HSC) for three habitat guilds and seven species of adult freshwater mussels. Nonparametric tolerance limits were used to define the range of suitable and optimal habitat during summer low flows. Optimal habitat was defined as those ranges of FST hemisphere number, mean column velocity, and embeddedness occupied by the central 50% of independent observations for a species or guild, whereas suitable habitat was defined by those ranges occupied by the central 90% of observations. The transferability of criteria to other reaches of the Clinch River was assessed using one-sided Chi-square tests. Criteria developed for the fast-flow specialist (FFS) and fast-flow generalist (FFG) guilds, as well as most criteria for species in those guilds, transferred to destination reaches. In contrast, criteria developed for the slow-flow tolerant (SFT) guild and individual constituent species consistently failed to transfer. Criteria for FFS and FFG guilds and their constituent species should be incorporated into flow simulation models such as PHABSIM to gauge the effect of minimum flows on mussel habitat quality and quantity. These criteria could also be used to determine suitable sites for mussel translocations. However, my criteria require further testing in other rivers before they can be transferred beyond the Clinch River. Behavior and physiological responses to laboratory manipulations of flow velocity and substrate particle size were used to elucidate microhabitat preferences of Actinonaias pectorosa, Potamilus alatus, and Ptychobranchus subtentum. These species appeared less stressed in the fastest flow treatment, demonstrating significantly higher oxygen consumption and oxygen-to-nitrogen (O:N) ratios than in slower flow treatments. Only P. alatus demonstrated a preference for substrate particle size, and consistently selected finer particle sizes. Actinonaias pectorosa and P. subtentum demonstrated preference for fast-flow microhabitats by readily burrowing in those conditions, while abandoning slow-flow conditions. The lack of preference for substrate particle size demonstrated by A. pectorosa and P. subtentum supports conclusions of previous studies that substrate particle size is of little or secondary importance for explaining mussel microhabitat use. These results, along with previous studies in the Clinch River, demonstrate that the stable habitats of riffles and runs; characterized by fast flows during summer low flows, low percent bedrock, and low embeddedness, are the most suitable habitats for mussel assemblages. To create and maintain suitable habitat conditions in tailwaters, releases should maintain flow over riffles at a minimum depth of no less than 30 cm in riffles that provide higher shear stress conditions (FST number > 7) and velocities (> 0.70 m/s). Periodic releases that are sufficient to transport silt and sand, but not high enough to transport larger substrate should be adequate to maintain substrates with a low degree of embeddedness. Doing so would create suitable habitat for all mussels, from the most to least specialized. Additionally, HSC developed for FFS and FFG guilds can be used to determine suitable destination sites for translocations of species belonging to these guilds. / Master of Science

Multi-disciplinary ship synthesis models and multi-objective optimization techniques are increasingly being used in ship design. Multi-disciplinary models allow designers to break away from the traditional design spiral approach and focus on searching the design space for the best overall design instead of the best discipline-specific design. Complex design problems such as these often have high levels of uncertainty associated with them, and since most optimization algorithms tend to push solutions to constraint boundaries, the calculated "best" solution might be infeasible if there are minor uncertainties related to the model or problem definition. Consequently, there is a need to address uncertainty in optimization problems to produce effective and reliable results. This thesis focuses on adding a third objective, uncertainty, to the effectiveness and cost objectives already present in a multi-disciplinary ship synthesis model. Uncertainty is quantified using a "confidence of success" (CoS) calculation based on the mean value method. CoS is the probability that a design will satisfy all constraints and meet performance objectives. This work proves that the CoS concept can be applied to synthesis models to estimate uncertainty early in the design process. Multiple sources of uncertainty are realistically quantified and represented in the model in order to investigate their relative importance to the overall uncertainty. This work also presents methods to encourage a uniform distribution of points across the Pareto front. With a well defined front, designs can be selected and refined using a gradient based optimization algorithm to optimize a single objective while holding the others fixed. / Master of Science

The efficiency of a best management practice (BMP) is defined simply as a measure of how well the practice or series of practices removes targeted pollutants. While this concept is relatively simple, mathematical attempts to quantify BMP efficiency are numerous and complex. Intuitively, the pollutant removal capability of a BMP should be fundamental to the BMP selection process. However, as evidenced by the absence of removal efficiency as an influential criterion in many BMP selection procedures, it is typically not at the forefront of the BMP selection and design process. Additionally, of particular interest to any developer or municipal agency is the financial impact of implementing a BMP. Not only does the implementation cost exist, but there are long-term maintenance costs associated with almost any BMP. Much like pollutant removal efficiency, implementation and maintenance costs seem as though they should be integral considerations in the BMP selection process. However, selection flow charts and matrices employed by many localities neglect these considerations. Among the categories of criteria to consider in selecting a BMP for a particular site or objective are site-specific characteristics; local, state, and federal ordinances; and implementation and long-term maintenance costs. A consideration such as long-term maintenance cost may manifest itself in a very subjective fashion during the selection process. For example, a BMPs cost may be of very limited interest to the reviewing locality, whereas cost may be the dominant selection criterion in the eyes of a developer. By contrast, the pollutant removal efficiency of a BMP may be necessarily prioritized in the selection process because of the required adherence to governing legislation. These are merely two possible criteria influencing selection. As more and more selection criteria are considered, the task of objectively and optimally selecting a BMP becomes increasingly complex. One mathematical approach for optimization in the face of multiple influential criteria is the Analytic Hierarchy Process. "The analytic hierarchy process (AHP) provides the objective mathematics to process the inescapably subjective and personal preferences of an individual or a group in making a decision" (Schmoldt, 2001, pg. 15). This paper details the development of two categories of comprehensive BMP selection matrices expressing long-term pollutant removal performance and annual maintenance and operations cost respectively. Additionally, the AHP is applied in multiple scenarios to demonstrate the optimized selection of a single BMP among multiple competing BMP alternatives. Pairwise rankings of competing BMP alternatives are founded on a detailed literature review of the most popular BMPs presently implemented throughout the United States. / Master of Science

Software testing is important, but judging whether a set of software tests is effective is difficult. This problem also appears in the classroom as educators more frequently include software testing activities in programming assignments. The most common measures used to assess student-written software tests are coverage criteria—tracking how much of the student’s code (in terms of statements, or branches) is exercised by the corresponding tests. However, coverage criteria have limitations and sometimes overestimate the true quality of the tests. This dissertation investigates alternative measures of test quality based on how many defects the tests can detect either from code written by other students—all-pairs execution—or from artificially injected changes—mutation analysis. We also investigate a new potential measure called checked code coverage that calculates coverage from the dynamic backward slices of test oracles, i.e. all statements that contribute to the checked result of any test. Adoption of these alternative approaches in automated classroom grading systems require overcoming a number of technical challenges. This research addresses these challenges and experimentally compares different methods in terms of how well they predict defect-detection capabilities of student-written tests when run against over 36,500 known, authentic, human-written errors. For data collection, we use CS2 assignments and evaluate students’ tests with 10 different measures—all-pairs execution, mutation testing with four different sets of mutation operators, checked code coverage, and four coverage criteria. Experimental results encompassing 1,971,073 test runs show that all-pairs execution is the most accurate predictor of the underlying defect-detection capability of a test suite. The second best predictor is mutation analysis with the statement deletion operator. Further, no strong correlation was found between defect-detection capability and coverage measures. / Ph. D.

Risk analysis is a powerful science-based tool that can be used to control and mitigate microbial food safety hazards. Codex recommends conducting preliminary risk management activities (PRMAs) to initiate risk analysis and to plan the risk assessment process. The information learned from these PRMAs should be utilized to construct a quantitative microbial risk assessment (QMRA) model. Then, risk management activities can utilize the QMRA model to identify and select microbial risk management (MRM) options. In this project, Codex recommendations for conducting risk analysis were followed to analyze the risk of acquiring salmonellosis from whole broiler (meat chickens) consumption within the United States. At the first stage, the risk of Salmonella on whole broilers was quantitatively estimated by attributing reported annual salmonellosis to whole broilers. A quantitative microbial risk assessment (QMRA) model was constructed to build an informative risk analysis model based on performance criteria, while minimizing associated modeling complications. The QMRA model was constructed in Excel® (Microsoft Corporation, Redmond, WA, USA) with the @RISK® Add-ins software (Palisade Corp., Ithaca, NY, USA). @RISK® software was used to perform Monte Carlo simulations that account for attendant uncertainties. After the model was tested and calibrated, it estimated the annual salmonellosis cases from whole broilers as 216,408 case/year that corresponds to the number of salmonellosis reported by Center for Disease and Control Prevention (CDC). Furthermore, sensitivity analysis was performed where 16 sensitive inputs (potential places for food safety interventions) and 10 data gaps (inputs that significantly affect the overall uncertainty) were reported. Some QMRA model results were transformed to MRM metrics. These MRM metrics, including ALOPs (Appropriate Level of Protection), FSOs (Food Safety Objectives), POs (Performance Objectives), and PC (Performance Criteria), were calculated along with a sampling plan for a food safety control system. The MRM metrics were utilized to identify and plan food control interventions such as risk communication, auditing, inspection, and monitoring. Furthermore, the QMRA model was utilized to identify and to quantitatively evaluate food safety interventions that affect Salmonella prevalence and/or concentration. / Ph. D.

The purpose of this study is to attempt establishment of ways by which Amarillo College, as a community junior college, can further extend its benefits to the adults of the community through its commercial curriculum.

Tesis por compendio / [EN] Academics, managerial and policy making community reinforce that renewable energy investments are one of the most effective instruments to attain CO2 emission reduction targets set by the Kyoto Protocol and by the recent Paris Agreement signed at the Paris climate conference (COP21) in December 2015 in which 195 countries adopted the first-ever universal, legally binding global climate deal. The problem of financing Renewable Energy (RE) projects has become a crucial issue for private and public decision makers worldwide. Budget constraints from governments and limited bank lending capacities have led to a reconsideration of the traditional financial instruments in the RE sector. The lack of credit makes impossible for commercial banks to fund RE projects with traditional loans. Research on new financing techniques for RE projects, such as Project Finance (PF) has gained interest in recent years. PF is a recent technique applied in large investments projects. During the last decades of the 20th century new public private partnership schemes enabled large infrastructure, energy and environmental projects. In these sectors PF has been used to reduce cost agency conflicts and better risk management. There is a wide number of contributions underlying the relevance of RE, however there is a lack of research on the financial aspects of RE projects. This research aims to make several contributions. First, to provide a better understanding of the PF technique and its use in the RE sector. Second, to fill the gap of research on financial aspects of RE in the literature by reviewing contributions of MCDM to RE project evaluation from the investor's perspective. Third, we propose a MPDM Moderate Pessimism Decision Making model, which adds to the rational financial evaluation of investment opportunities a set of non-financial factors that affects the investor's decisions. Finally, within the illustrative example, we apply this multi-criteria decision making process to help banks to decide if they must join a project or not. / [ES] Investigadores, comunidad empresarial y clase política destacan que la inversión en energías renovables es uno de los instrumentos más efectivos para alcanzar los objetivos de reducción de CO2 establecidos por el reciente acuerdo firmado en la conferencia de Paris (COP21) en diciembre de 2015, en el cual, 195 países adoptaron el primer acuerdo universal y jurídicamente vinculante de la historia. El problema de la financiación de los proyectos de energía renovable (RE) es un tema crucial para cualquier decisor público o privado. Las limitaciones presupuestarias de los gobiernos y la falta de crédito han provocado que se reconsideren los instrumentos de financiación en el sector de las RE, por lo tanto, la investigación en nuevas técnicas de financiamiento para los proyectos de RE, como Project Finance (PF) ha ganado interés en los últimos años. PF es una técnica que se aplica en grandes proyectos de inversión. A finales del Siglo XX, los nuevos esquemas de colaboración público-privadas han permitido llevar a cabo grandes proyectos de infraestructuras y de RE. En estos sectores, el PF se ha utilizado para reducir costes, conflictos y mitigar riesgos. Numerosas contribuciones científicas subrayan la importancia de la RE, sin embargo hay un vacío en la investigación sobre los aspectos financieros de los proyectos de RE. Esta tesis tiene como objetivo aportar varias contribuciones. En primer lugar, proporcionar una mejor comprensión de la técnica del PF y su uso en el sector de las RE. En segundo lugar, cubrir el vacío existente en la literatura sobre la investigación de los aspectos financieros de las RE mediante la revisión de las contribuciones sobre MCDM para la evaluación de los proyectos de RE desde el punto de vista del inversor. En tercer lugar, se propone un modelo MPDM (Moderate Pessimism Decision Making), el cual añade a la evaluación financiera racional de oportunidades de inversión, un conjunto de factores no financieros que afectan a las decisiones de los inversores. Finalmente, se aplica este modelo multicriterio de toma de decisiones para ayudar a decidir a los bancos si deben unirse al proyecto. / [CA] Investigadors, comunitat empresarial i classe política, destaquen que la inversió en energies renovables és un dels instruments més efectius per assolir els objectius de reducció de les emissions de CO2 establerts pel recent acord signat a la conferència de Paris (COP21) al desembre de 2015, mitjançant el qual, 195 països van adoptar el primer acord universal i jurídicament vinculant de la història. El problema del finançament dels projectes d'energia renovable (RE) s'ha convertit en un tema crucial per a qualsevol decisor públics i privats. Les limitacions pressupostàries dels governs i La falta de crèdit han provocat que es reconsiderin els instruments de finançament en el sector de les RE, per tant, la investigació en noves tècniques de finançament per als projectes de RE, com el Project Finance (PF) ha guanyat interès en els últims anys. PF és una tècnica que s'aplica en grans projectes d'inversió. Durant les últimes dècades del Segle XX, els nous esquemes de col-laboració publico-privades han permès portar a terme grans projectes d'infraestructures i de RE. En aquests sectors, el PF s'ha utilitzat per reduir costos, conflictes i gestionar millor els riscos. Existeixen nombroses contribucions científiques que subratllen la importància de la RE, però hi ha un buit en la investigació pel que fa als aspectes financers dels projectes de RE. Aquesta tesis té com a objectiu aportar diverses contribucions. En primer lloc, proporcionar una millor comprensió de la tècnica del PF i el seu ús en el sector de les RE. En segon lloc, cobrir el buit existent en la literatura sobre la investigació dels aspectes financers de les RE mitjançant la revisió de les contribucions sobre MCDM per a l'avaluació dels projectes de RE des del punt de vista de l'inversor. En tercer lloc, es proposa un model MPDM Moderate Pessimism Decision Making, que afegeix a l'avaluació financera racional d'oportunitats d'inversió, un conjunt de factors no financers que afecten les decisions dels inversors. Finalment, mitjançant un exemple il-lustratiu, s'aplica aquest model multicriteri de presa de decisions per ajudar a decidir als bancs si han de unir-se al projecte. / Mayor Vitoria, F. (2016). Project Finance and MCDM financial models: An application in renewable energy projects [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/73067 / Compendio