Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Arnold H. Buss, David A. Schrady. Includes bibliographical references (p. 107-108). Also available online.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, September 2003. / Thesis advisor(s): Arnold H. Buss, Kevin J. Maher. Includes bibliographical references (p. 147-148). Also available online.

Dans cette thèse, nous nous intéressons à l’optimisation robuste. Plus précisément,nous nous intéresserons aux problèmes linéaires mixtes bi-niveaux, c’est à dire aux problèmes dans lesquels le processus de décision est divisé en deux parties : dans un premier temps, les valeurs optimales des variables dites "de décisions" seront calculées ; puis, une fois que l’incertitude sur les données est levée, nous calculerons les valeurs des variables dites "de recours". Dans cette thèse, nousnous limiterons au cas où les variables de deuxième étape, dites "de recours", sontcontinues.Dans la première partie de cette thèse, nous nous concentrerons sur l’étudethéorique de tels problèmes. Nous commencerons par résoudre un problème linéairesimplifié dans lequel l’incertitude porte seulement sur le membre droit descontraintes, et est modélisée par un polytope bien particulier. Nous supposerons enoutre que le problème vérifie une propriété dite "de recours complet", qui assureque, quelles que soient les valeurs prises par les variables de dcisions, si ces dernières sont admissibles, alors le problème admet toujours une solution réalisable, et ce, quelles que soient les valeurs prises par les paramètres incertains. Nous verrons alors une méthode permettant, à partir d’un programme robuste quelconque, de se ramener à un programme robuste équivalent dont le problème déterministe associévérifie la propriété de recours complet. Avant de traiter le cas général, nous nouslimiterons d’abord au cas o les variables de décisions sont entières. Nous testeronsalors notre approche sur un problème de production. Ensuite, après avoir remarquéque l’approche développée dans les chapitres précédents ne se généralisait pasnaturellement aux polytopes qui n’ont pas des points extrmes 0-1, nous montreronscomment, en utilisant des propriétés de convexité du problème, résoudre le problème robuste dans le cas général. Nous en déduirons alors des résultats de complexité sur le problème de deuxième étape, et sur le problème robuste. Dans la suite de cette partie nous tenterons d’utiliser au mieux les informations probabilistes que l’on a sur les données aléatoires pour estimer la pertinence de notre ensemble d’incertitude.Dans la deuxième partie de cette thèse, nous étudierons un problème de conceptionde parc hybride de production d’électricité. Plus précisément, nous chercheronsà optimiser un parc de production électrique constitué d’éoliennes, de panneauxsolaires, de batteries et d’un générateur à diesel, destiné à répondre à unedemande locale d’énergie électrique. Il s’agit de déterminer le nombre d’éoliennes,de panneaux solaires et de batteries à installer afin de répondre à la demande pourun cot minimum. Cependant, les données du problème sont très aléatoires. En effet,l’énergie produite par une éolienne dépend de la force et de la direction du vent ; celle produite par un panneau solaire, de l’ensoleillement et la demande en électricité peut tre liée à la température ou à d’autres paramètres extérieurs. Pour résoudre ce problème, nous commencerons par modéliser le problème déterministeen un programme linéaire mixte. Puis nous appliquerons directement l’approche de la première partie pour résoudre le problème robuste associé. Nous montrerons ensuite que le problème de deuxième étape associé, peut se résoudre en temps polynomial en utilisant un algorithme de programmation dynamique. Enfin, nous donnerons quelques généralisations et améliorations pour notre problème. / Robust optimization is a recent approach to study problems with uncertain datathat does not rely on a prerequisite precise probability model but on mild assumptionson the uncertainties involved in the problem.We studied a linear two-stage robustproblem with mixed-integer first-stage variables and continuous second stagevariables. We considered column wise uncertainty and focused on the case whenthe problem doesn’t satisfy a "full recourse property" which cannot be always satisfied for real problems. We also studied the complexity of the robust problemwhich is NP-hard and proved that it is actually polynomial solvable when a parameterof the problem is fixed.We then applied this approach to study a stand-alonehybrid system composed of wind turbines, solar photovoltaic panels and batteries.The aim was to determine the optimal number of photovoltaic panels, wind turbinesand batteries in order to serve a given demand while minimizing the total cost of investment and use. We also studied some properties of the second stage problem, in particular that the second stage problem can be solvable in polynomial time using dynamic programming.

Aim of the study: Identification of operational development factors applicable to Laboratory N. Objectives: 1) identify the peculiarities of laboratory strategy development, 2) analyse the existing situation, assess current technological developments and utilisation of information technologies, 3) forecast the scope of services provided by Laboratory N. Key words: laboratory, operational development. Methods: The location of research is the Outpatient Clinic N and its subsidiary, i.e. Laboratory N. The object of research is the operational development opportunities of the laboratory. Scientific literature and legal documents were analysed. Statistical data for 2002-2005 on the scope of laboratory services for the whole of Lithuania and for the outpatient clinic (as at 31 December 2005) was collected. The existing structure of the subsidiary was analysed, operational processes were described, calculations were made and the scope of services by 2010 was forecasted. In January 2006, a structured interview was held with four heads of departments in order to broader depict the operational context of the object under research and to collect extensive information. Then doctors were surveyed. More than 200 questionnaires were distributed, however, only 187 doctors provided comprehensive answers to the questions included into the questionnaire, 2 questionnaires were only partially filled out and thus discarded in the process of data analysis, while 11 potential respondents never... [to full text]

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Sexual conflict occurs when individuals of one sex express traits that reduce the fitness of their mates. Males of many species harass females to gain copulations, which benefits males by increasing the number of offspring they sire but imposes energetic and opportunity costs on the females they harass. This thesis examined the fitness costs of sexual harassment to females, the energetic costs of mating to males, and the factors influencing the intensity of male competition for mates in the western mosquitofish Gambusia affinis. I quantified male and female behavior, four female fitness components (number of offspring per female, embryo number, growth, and survival), and an index of male body condition in response to changes in operational sex ratio (experiment 1) and male and female density (experiment 2). I found that a strong, negative effect of female density on female fitness overwhelmed any potential costs of male harassment, suggesting that ecological interactions between females may play a larger role in determining female fitness than conflict between the sexes. Agonistic chases and displays between males increased as the operational sex ratio increased (became male-biased), while the number of copulations males attempted decreased. This inverse relationship suggests a tradeoff between interfering with other males and attempting additional copulations with females. Increases in chases between males were largely due to changes in female density, but not male density, suggesting that the availability of females determines whether males escalate contests with other males. In contrast, the number of displays between males depended varied with male density but did not female density. This difference between chases and displays is likely due to their difference in function; chases are performed to prevent other males from mating while displays are used to assess male competitors. I did not detect any energetic cost of mating to males.

A logical framework and its implementation should serve as a flexible tool for specifying, simulating, and reasoning about formal systems. When the formal systems we are interested in exhibit state and concurrency, however, existing logical frameworks fall short of this goal. Logical frameworks based on a rewriting interpretation of substructural logics, ordered and linear logic in particular, can help. To this end, this dissertation introduces and demonstrates four methodologies for developing and using substructural logical frameworks for specifying and reasoning about stateful and concurrent systems. Structural focalization is a synthesis of ideas from Andreoli’s focused sequent calculi and Watkins’s hereditary substitution. We can use structural focalization to take a logic and define a restricted form of derivations, the focused derivations, that form the basis of a logical framework. We apply this methodology to define SLS, a logical framework for substructural logical specifications, as a fragment of ordered linear lax logic. Logical correspondence is a methodology for relating and inter-deriving different styles of programming language specification in SLS. The styles we connect range from very high-level specification styles like natural semantics, which do not fully specify the control structure of programs, to low-level specification styles like destination-passing, which provide detailed control over concurrency and control flow. We apply this methodology to systematically synthesize a low-level destination-passing semantics for a Mini-ML language extended with stateful and concurrent primitives. The specification is mostly high-level except for the relatively few rules that actually deal with concurrency. Linear logical approximation is a methodology for deriving program analyses by performing abstract analysis on the SLS encoding of the language’s operational semantics. We demonstrate this methodology by deriving a control flow analysis and an alias analysis from suitable programming language specifications. Generative invariants are a powerful generalization of both context-free grammars and LF’s regular worlds that allow us to express invariants of SLS specifications in SLS.We show that generative invariants can form the basis of progress-andpreservation- style reasoning about programming languages encoded in SLS.