Dissertations / Theses on the topic 'Lineage decision'
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Meng, Lingzhang [Verfasser]. "The impact of B-lineage derived IL-10 on fate decision of monocyte differentiation / Lingzhang Meng." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2016. http://d-nb.info/1096832577/34.
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Chain, Jennifer Lee. "Elucidating the mechanisms of the human [alphabeta] vs. [gammadelta] lineage decision and the details of [gammadelta] thymocyte development." Oklahoma City : [s.n.], 2005.
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Bröske, Ann-Marie Elisabeth. "The level of DNA methylation impacts self-renewal capacity and lineage choices of hematopoietic stem cells." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2010. http://dx.doi.org/10.18452/16099.
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DNS-Methylierung ist ein zentraler epigenetischer Prozess, der essentiell für die Differenzierung embryonaler Stammzellen ist, über dessen Funktion in somatischen Zellen allerdings wenig bekannt ist. In der vorliegenden Doktorarbeit wurden zwei Mausmodelle analysiert, um die Rolle der durch DNS Methyltransferase 1 (DNMT1) hergestellten DNS-Methylierung im adulten hämatopoetischen System zu untersuchen. Als erstes wurde ein „Knockout“-Modell gewählt, um DNMT1 im hämatopoetischen System zu eliminieren. Des Weiteren wurde eine Mausmutante mit reduzierter DNMT1 Expression analysiert. Die vollständige Entfernung von DNMT1 aus dem hämatopoetischen System adulter Mäuse resultierte in Zytopenie und Anämie, gefolgt vom raschen Tod aller Tiere. Die Analyse des Knochenmarks dieser Mäuse zeigte einen fast vollständigen Verlust von hämatopoetischen Stamm- sowie Vorläuferzellen. Dies zeigt, dass die durch DNMT1 erzeugte DNS-Methylierung essentiell für Homöostase und Differenzierung von hämatopoetischen Stammzellen ist. Mäuse mit reduzierter DNMT1 Expression hingegen sind lebensfähig und zeigen einen niedrigen Grad an DNS-Methylierung in verschiedensten Geweben, einschließlich des hämatopoetischen Systems. Durch eine detaillierte phänotypische und funktionelle Analyse der hämatopoetischen Stammzellen zeigte sich, dass der veränderte DNS-Methylierungsgrad ein vermindertes Selbsterneuerungspotenzial zur Folge hat. Interessanterweise fehlen DNMT1 hypomorphen Mäusen lymphoide Vorläuferzellen sowie reife lymphoide Zellen, wohingegen myeloide und erythroide Zellpopulationen keine Veränderungen zeigten. Genomweite Expressionsanalysen von Stammzellen sowie myeloiden Vorläuferzellen zeigten, dass hypomethylierte Stammzellen eine verfrühte myeloerythroide Entwicklung vollziehen und liefern damit eine Erklärung für den Verlust des Selbsterneurungspotenzials und der lymphoiden Entwicklung. Diese Resultate identifizieren eine bis hierhin unbekannte Funktion von spezifischen DNS-Methylierungsgraden für die Steuerung von funktionellen Programmen wie Selbsterneuerung und Differenzierung in hämatopoetischen Stammzellen.DNA methylation is one of the major epigenetic mechanisms which is known to play a role in embryonic stem cell fate, but its function in somatic stem cells is not well understood. In this thesis two different genetic mouse models were chosen to address the role of DNA methyltransferase 1 (DNMT1) controlled DNA methylation in adult hematopoiesis. First, a conditional knockout approach was used to delete DNMT1 in the adult hematopoietic system. Second, DNMT1 hypomorphic mice with reduced DNMT1 expression were analyzed. Complete DNMT1 deletion in hematopoietic cells led to severe cytopenia and anemia causing rapid lethality of all animals. Bone marrow analysis revealed an almost complete absence of hematopoietic stem and progenitor cells in DNMT1 ablated primary mice as well as in secondary chimeric mice. These results indicated that DNMT1 controlled maintenance of DNA methylation is indispensable for HSCs preservation and differentiation. In contrast to complete DNMT1 deletion, mice with hypomorphic DNMT1 expression were viable, but showed low methylation levels in multiple tissues including the hematopoietic system. Detailed phenotypical and functional analysis of the hypomethylated hematopoietic stem cell (HSCs) compartment revealed an impaired homeostasis and self-renewal capacity. Intriguingly, mutant animals had profoundly reduced lymphoid cell compartments, whereas myeloid and erythroid compartments were unchanged. Expression profiling of stem and myeloid progenitor cells unexpectedly demonstrated that reduced DNA methylation forces the HSC to adopt a myeloid lineage identity. These results, showing the inability of hypomethylated HSCs to maintain an undifferentiated state, provided an explanation for their disturbed capability to self-renew and produce lymphocytes. Taken together, these findings suggest that distinct levels of DNA methylation are required to control different functional programs such as self-renewal and alternative lineage choices in HSCs, thus uncovering a previously unrecognized function for DNMT1 activity.
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Di, Tullio Alessandro 1982. "Reprogramming of B cells into macrophages: mechanistic insights." Doctoral thesis, Universitat Pompeu Fabra, 2012. http://hdl.handle.net/10803/85722.
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Our earlier work has shown that pre-B cells can be converted into macrophages by the transcription factor C/EBPα at very high frequencies and also that a clonal pre-B cell line with an inducible form of C/EBPα can be converted into macrophage-like cells. Using these systems we have performed a systematic analysis of the questions whether during transdifferentiation the cells retrodifferentiate to a precursor cell state and whether cell cycle is required for reprogramming.
As for the first question, a transcriptome analysis of transdifferentiating cells showed that most genes are continuously up or downregulated, acquiring a macrophage phenotype within 5 days. In addition, we observed the transient reactivation of a subset of immature myeloid markers, as well as low levels of the progenitor markers Kit and Flt3 and a few lineage inappropriate genes. Importantly, we were unable to observe the re-expression of cell surface marker combinations that characterize hematopoietic stem and progenitor cells (HSPCs), including c-Kit and Flt3. This was the case even when C/EBPα was activated in pre-B cells under culture conditions that favor HSPC growth or when the transcription factor was activated in a time limited fashion.
As for the second question, using the C11-inducible pre-B cell line, time-lapse experiments showed that a subpopulation of about 8% of the pre-B cells did not divide before acquiring macrophage properties, with the majority of cells dividing once and a few percent dividing twice. In agreement with these results we found that 8% of the induced cells did not incorporate BrdU during reprogramming. Importantly, the non-dividing cell subset expressed the highest levels of C/EBPα and was the fastest in acquiring a macrophage phenotype. Inhibition of DNA synthesis by aphidicolin led to an impairment of transdifferentiation in >70% of the cells, suggesting a requirement for traversing the cell cycle. However, sorting pre-B cells into G0/G1 and G2/M fractions followed by induction showed no significant differences in the reprogramming kinetics. Finally, we showed that knocking down p53 in the inducible pre-B cells does not alter their conversion into macrophages, suggesting that an acceleration of the cell cycle has no effect.
Together, our findings show that the conversion of pre-B cells to macrophages does not involve overt retrodifferentiation and that high concentrations of C/EBPα bypass the cell cycle-dependency of immune cell transdifferentiationRecientemente, nuestro grupo ha demostrado que las células pre-B se pueden reprogramar a macrófagos mediante la sobreexpresión del factor de transcripción C/EBP, con una eficiencia elevada. Así mismo, mediante la expresión de la forma inducible de C/EBP en una línea de células pre-B (C11), éstas también se puede convertir en células similares a macrófagos. Usando este sistema hemos estudiado si durante el proceso de trans-diferenciacion las células requieren volver a un estadio de célula precursora, y si el ciclo celular es necesario para este proceso. En cuanto a la primera cuestión, el análisis del transcriptoma de células trans-diferenciadas mostró que la expresión de la mayoría de los genes están regulados durante todo el proceso bien aumentando o disminuyendo, y que adquieren el fenotipo de macrófago a los 5 días después de iniciar el proceso. Así mismo, se observó la reactivación transitoria de un grupo de genes que codifican para marcadores de células mieloides inmaduras; también cabe destacar que observamos una disminución en la expresión de los genes expresados en células progenitoras Kit y Flt3, así como de genes de linajes impropios. Es importante destacar que nunca hemos llegado a observar la expresión de combinaciones de marcadores de superficie característicos de las células madre hematopoyéticas y las células progenitoras (HSPCs), incluyendo c-Kit y Flt3, mediante el análisis por citometría de flujo. Estos resultados se reprodujeron incluso cuando C/EBP se sobreexpresó en células pre-B que fueron cultivadas en condiciones que favorecen el crecimiento de las HSPC o cuando el factor de transcripción se activó de forma limitada en el tiempo. En cuanto a la segunda pregunta, usando la línea de células inducibles pre-B C11, el análisis mediante microscopia a diferentes tiempos después de la inducción de la reprogramación mostraron que una subpoblación de aproximadamente el 8% de las células pre-B no se dividen antes de adquirir las propiedades de macrófago, mientras que la mayoría de las células se dividen sólo una vez y un pequeño porcentaje dos veces antes de que se reprogramen totalmente a macrófagos. De acuerdo con estos resultados se encontró que un 8% de las células inducidas no incorporan BrdU durante la reprogramación. Es importante destacar que el subconjunto de células que no se dividen expresan los niveles más altos de C/EBP, con lo que cabe pensar que la adquisición del fenotipo de macrófago es más rápida en estas células. La inhibición de la síntesis de ADN por afidicolina bloqueó la transdiferenciación en mas de un 70% de las células, lo que sugiere que la correcta progresión del ciclo celular es un requisito para la transdiferenciación. Sin embargo, al separar la linea de células pre-B C11 en fracciones G0/G1 y G2/M seguido de la inducción, la cinética de la reprogramación no mostró diferencias significativas. Por último, también demostramos que la reducción en la expresión de p53 en las células pre-B inducibles no altera el proceso de conversión a macrófago, lo que sugiere que la aceleración del ciclo celular no tiene ningún efecto. En conjunto, nuestros resultados muestran que la conversión de células pre-B a macrófagos no requiere retro-diferenciación y que las células con una expresión mayor de C/EBP pueden llegar a prescindir de la dependencia del ciclo celular para la trans-diferenciación de las células inmunitarias.
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Morgani, Sophie Maria. "Signalling and transcriptional regulation of early developmental lineage decisions." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/9660.
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Embryonic stem (ES) cells are cell lines isolated from the embryo at a time just prior to implantation into the uterus. In the right cocktail of medium and cytokines, these cell lines can be maintained indefinitely in vitro in a self-renewing state. Initially it was assumed that these cells represented a homogeneous population however, more recently it has been shown that there are a great number of genes that are expressed heterogeneously. ES cell cultures are therefore a mix of different subpopulations, some of which have distinct functional properties including a bias or ‘lineage priming’ towards a particular cell fate. These populations are also dynamic in nature, converting from one state to another with fairly rapid kinetics. The main focus of this thesis was to gain a more in depth understanding of the mechanisms regulating heterogeneity and lineage priming in murine ES cells by asking which signalling pathways play a role in this phenomenon and how the switch between states is regulated at a transcriptional level. These questions were asked using an ES cell line containing a sensitive reporter for the endoderm marker Hex. This reporter, developed by a previous lab member, allowed the identification and separation of a population of ES cells primed towards a primitive endoderm fate. Primarily, I assessed the effect of a defined culture system (2i) on the Hex-expressing population. This culture system contains inhibitors that block FGF signalling and the Wnt pathway component GSK3. Culturing ES cells in 2i has been suggested to generate a more homogeneous culture. Here, I have shown that culturing ES cells or pre-implantation embryos in 2i did not eliminate heterogeneity but maintained them in an early state prior to lineage segregation. When ES cells were cultured in standard serum-containing medium, Hex was expressed in a mutually exclusive manner with the embryonic marker NANOG, while in 2i a subpopulation of cells coexpressed both Hex and NANOG. This population was functionally primed towards extraembryonic endoderm and trophoblast. Furthermore, these ES cells could efficiently contribute to 2-cell embryos in chimaera assays. LIF signalling promoted this population through the JAK/STAT pathway. I then asked how transcription was regulated during the switch between unprimed ES cells to those primed towards a primitive endoderm fate, as well as how regulation changes during further differentiation. To ask this, Hex positive (primed) and negative (unprimed) ES cell populations were sorted as well as a Hex positive differentiated sample. These samples were analysed by GRO-seq to determine the location, density and orientation of RNA-polymerase throughout the genome. Changes in gene expression between primed and unprimed states were regulated primarily through elongation whereas genes upregulated during differentiation were regulated at the point of de novo initiation.
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Koutsoukis, Nikitas-Spiros. "Decision modelling and information systems : the interaction of information and decision technologies." Thesis, Brunel University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263519.
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Braathen, Jørgen, and Anders Lund Eriksrud. "Hydropower Bidding Using Linear Decision Rules." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for industriell økonomi og teknologiledelse, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24844.
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This thesis investigates the Linear Decision Rule (LDR) approach applied to the bidding problem of a Nordic hydropower producer with reservoir capacity. A stochastic programming model with piecewise LDR in the spot prices is developed. A comprehensive case study with uncertain spot prices conducted for the fall of 2012 shows that the LDR model performs equally well as a scenario based model on expectation, yet with a smaller standard deviation in the profits. The runtime of the LDR model is substantially longer than the runtime of the scenario based model. Therefore, promising techniques to reduce the runtime are developed and presented.
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Mendes, Mirian Patricia Sanches. "Aplicação da programação linear na decisão económica de investimento." Master's thesis, Instituto Politécnico de Setúbal. Escola Superior de Ciências Empresariais, 2014. http://hdl.handle.net/10400.26/7883.
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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de
Mestre em Contabilidade e FinançasConsiderando o atual contexto empresarial, que se caracteriza por uma elevada competitividade a nível global, é essencial que os gestores tomem decisões que contribuam para criação de valor e para a sustentabilidade competitiva das empresas. Assim, o objetivo desta dissertação de mestrado é evidenciar que a programação linear pode contribuir para a maximização da criação de valor, através da sua utilização no estudo das decisões económicas de investimento das empresas. Tais decisões acarretam riscos elevados porque condicionam a capacidade de produção e o tipo de vantagens competitivas a criar e, por isso, devem ser capazes de responder ao nível de crescimento esperado do mercado e aos fatores críticos de sucesso dos negócios. Para além disso, são decisões que envolvem normalmente montantes avultados de capitais e que exigem a entrada de dinheiro por parte dos proprietários e a negociação de fontes de financiamento de médio e longo prazo que irão condicionar durante muito tempo a tesouraria da empresa. Como tal, este trabalho de investigação pretende, através da realização de um estudo de caso sobre uma empresa de serviços, evidenciar que a programação linear poderá dar um forte contributo sobre a otimização deste tipo de decisões. O trabalho é constituído por duas partes principais. A primeira contém uma revisão bibliográfica dos principais assuntos abordados, tanto ao nível dos conceitos financeiros como da programação linear. A segunda parte, relativa ao estudo empírico, é constituída pelo capítulo 3, onde são descritos mais em pormenor os objetivos e a metodologia de investigação utilizada e pelo capítulo 4 onde é desenvolvido o estudo de caso. Por fim, ainda são apresentadas as principais conclusões sobre o trabalho desenvolvido. Ao nível dos resultados de investigação obtidos, demonstra-se que através da aplicação da programação linear é possível maximizar os cash-flows anuais, através da determinação do mix de serviços que a empresa deve oferecer, considerando os preços de venda, a estrutura de custos e de ativos, bem como a capacidade dos recursos existentes (Horas/Homem de cada tipo de serviço a realizar).
Considering the current business environment that is characterized by high global competitiveness, it is essential that managers make decisions that contribute to value creation and competitive sustainability of companies. Thus, the objective of this thesis is to show that linear programming can contribute to the maximization of value creation through their use in the study of economic investment decisions of companies. Such decisions entail high risks, because they limited the capacity and the type of competitive advantages to create, and therefore must be able to respond to the expected level of market growth and to the critical factors of business success. Furthermore those decisions usually involve large amounts of capital and require entry of money by owners and the negotiation of medium and long term funding sources that will limit for a long time the treasure of the company. As such, this research work intends to show, by conducting a case study on a service company, that linear programming can make a strong contribution on the optimization of these kinds of decisions. The thesis consists of two mains parts. The first part contains a literature review of the main issues discussed both to the concept of financial and linear programming. The second part on the empirical study is composed by chapter 3 where described in more detail the objectives and the methodology used, and chapter 4 where the case study is developed. In relation to the results of the investigation, it is demonstrated that by applying linear programming it is possible to maximize the annual cash flows, by determining the mix of services that the company should offer, considering the sales prices, the structure of costs and assets, as well as the capacity of existing resources (hours/man of each type of service to be attain).
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Patrascu, Relu-Eugen. "Linear Approximations For Factored Markov Decision Processes." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/1171.
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A Markov Decision Process (MDP) is a model employed to describe problems in which a decision must be made at each one of several stages, while receiving feedback from the environment. This type of model has been extensively studied in the operations research community and fundamental algorithms have been developed to solve associated problems. However, these algorithms are quite inefficient for very large problems, leading to a need for alternatives; since MDP problems are provably hard on compressed representations, one becomes content even with algorithms which may perform well at least on specific classes of problems. The class of problems we deal with in this thesis allows succinct representations for the MDP as a dynamic Bayes network, and for its solution as a weighted combination of basis functions. We develop novel algorithms for producing, improving, and calculating the error of approximate solutions for MDPs using a compressed representation. Specifically, we develop an efficient branch-and-bound algorithm for computing the Bellman error of the compact approximate solution regardless of its provenance. We introduce an efficient direct linear programming algorithm which, using incremental constraints generation, achieves run times significantly smaller than existing approximate algorithms without much loss of accuracy. We also show a novel direct linear programming algorithm which, instead of employing constraints generation, transforms the exponentially many constraints into a compact form more amenable for tractable solutions. In spite of its perceived importance, the efficient optimization of the Bellman error towards an approximate MDP solution has eluded current algorithms; to this end we propose a novel branch-and-bound approximate policy iteration algorithm which makes direct use of our branch-and-bound method for computing the Bellman error. We further investigate another procedure for obtaining an approximate solution based on the dual of the direct, approximate linear programming formulation for solving MDPs. To address both the loss of accuracy resulting from the direct, approximate linear program solution and the question of where basis functions come from we also develop a principled system able not only to produce the initial set of basis functions, but also able to augment it with new basis functions automatically generated such that the approximation error decreases according to the user's requirements and time limitations.
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Spiropoulos, Takis. "Decision support for management using Bayes linear influence diagrams." Thesis, University of Sunderland, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259788.
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Shcherban, V. Yu. "Algorithmic and programmatic providing decision systems of linear equalizations." Thesis, Київський національний університет технологій та дизайну, 2019. https://er.knutd.edu.ua/handle/123456789/14586.
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Nadal, Roig Esteve. "Optimization models forimproving the decision-making in the pig production process under a Pig Supply Chain context." Doctoral thesis, Universitat de Lleida, 2019. http://hdl.handle.net/10803/669206.
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Aquesta tesi se centra en l’estructura de cadena de subministrament plantejada en el sector porcí on les petites empreses i els productors de porcs estan integrats verticalment, s'especialitzen i treballen junts sota el paraigua de grans empreses o cooperatives.
Aquestes cadenes de suministrament tenen avantatges competitius. No obstant això, els gerents han de considerar els nous problemes inexistent fins ara.
Per tant, aquesta tesi desenvolupa un conjunt de models de decisió basats en Optimització per ajudar en el procés de presa de en 1) Balancejar l'impacte de les emissions en el sistema de producció porcina mitjançant el desenvolupament d'un model de decisió sota una perspectiva econòmica 2) Desenvolupar un model de decisió multiperíode i multigranja per a la planificació de la producció tenint en compte les característiques del procés de producció, i 3) desenvolupar un model de decisió per a planificar decisions tàctiques en el procés de producció de porcs per augmentar l'eficiència.
Aquesta tesi demostra que l'ús de models desenvolupats brinda beneficis en el procés de presa de decisions, emfatitza la complexitat computacional de modelar un sistema integrat i obre noves oportunitats de recerca en el sector porcí.Esta tesis se centra en la estructura de cadena de suministro planteada en el sector porcino donde las pequeñas empresas y los productores de cerdos están integrados verticalmente, se especializan y trabajan juntos bajo el paraguas de grandes empresas o cooperativas. Estas cadenas de suministro tienen ventajas competitivas. Sin embargo, los gerentes deben considerar los nuevos problemas inexistente hasta ahora. Por tanto, esta tesis desarrolla un conjunto de modelos de decisión basados en Optimización para ayudar en el proceso de toma de en 1) Balancear el impacto de las emisiones en el sistema de producción porcina mediante el desarrollo de un modelo de decisión bajo una perspectiva económica 2) desarrollar un modelo de decisión multiperíodo y multigranja para la planificación de la producción teniendo en cuenta las características del proceso de producción, y 3) desarrollar un modelo de decisión para planificar decisiones tácticas en el proceso de producción de cerdos para aumentar la eficiencia. Esta tesis demuestra que el uso de modelos desarrollados brinda beneficios en el proceso de toma de decisiones, enfatiza la complejidad computacional de modelar un sistema integrado y abre nuevas oportunidades de investigación en el sector porcino.
This thesis focuses on the structure of supply chain raised in the pig sector where small pig companies and producers are vertically integrated, specialized and work together under the umbrella of large companies or cooperatives. These supply chains have competitive advantages. However, managers have to consider the new problems. Therefore, this thesis develops a set of decision-making models based on Optimization to help in the decision-making process to 1) Balance the impact of emissions on the pig production system by developing a decision model under a economic perspective 2) Develop a multi-period and multisite decision model for production planning taking into account the characteristics of the production process, and 3) develop a decision model to plan tactical decisions in the pig production process for increasing the efficiency. This thesis shows that the use of developed models provides benefits in the decision-making process, emphasizes the complexity of computing modeling an integrated system and opens new research opportunities in the pig sector.
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Makaya, Makaya L. "Interactive methods for multiple objective linear programming in decision support." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/4385.
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Bromberger, Martin [Verfasser], and Christoph [Akademischer Betreuer] Weidenbach. "Decision procedures for linear arithmetic / Martin Bromberger ; Betreuer: Christoph Weidenbach." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2020. http://d-nb.info/1207833657/34.
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Sharp, Leslie L. "Studies on the role of the erk MAPK pathway in thymocyte lineage commitment decisions /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p9944213.
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Torcal, Garcia Guillem 1991. "Methylation of a lineage-instructive transcription factor acts as a cell fate switch." Doctoral thesis, TDX (Tesis Doctorals en Xarxa), 2022. http://hdl.handle.net/10803/673532.
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Lineage-instructive transcription factors orchestrate cell fate decisions by regulating gene expression programs. However, how their function is regulated throughout development is poorly understood. C/EBPα is a transcription factor that has been shown to play a key role in several cell fate decisions of several tissues, including myelopoiesis, adipogenesis and early embryo development. The protein arginine methyltransferase Carm1 has also been described to play a role in cell specification during various developmental processes, but a connection to C/EBPα has not been established. In this Thesis, we investigated the link between the two proteins in cell fate decisions. We found that arginine 35 of C/EBPα is a key target of Carm1 methylation, and that this post-translational modification alters the biological properties of the factor and acts as a cell fate switch during myelopoiesis, adipogenesis and the first cell fate decision between pluripotency and trophectoderm in early embryos.Los factores de transcripción instructores de linaje orquestan decisiones de identidad celular a través de la regulación de programas de expresión génica. Sin embargo, cómo su función está regulada durante el desarrollo todavía se desconoce. C/EBPα es un factor de transcripción que juega un papel clave en varias decisiones de identidad celular, incluyendo mielopoiesis, adipogénesis y el desarrollo embrionario temprano. La metiltransferasa de argininas Carm1 también está involucrada en los mismos procesos, pero todavía no se ha descrito una posible conexión con C/EBPα. En esta Tesis, hemos investigado la conexión entre éstas dos proteínas en decisiones de identidad celular. Hemos descubierto que la arginina 35 de C/EBPα es un blanco clave para la metilación por Carm1, y está modificación postraduccional altera las propiedades biológicas del factor y actúa como un interruptor de identidad celular en mielopoiesis, adipogénesis y en la primera decisión entre pluripotencia y trofectodermo en el embrión.
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Wolff-Piggott, Timothy. "Identifying predictors of evolutionary dispersion with phylogeographic generalised linear models." Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25651.
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Discrete phylogeographic models enable the inference of the geographic history of biological organisms along phylogenetic trees. Frequently applied in the context of epidemiological modelling, phylogeographic generalised linear models were developed to allow for the evaluation of multiple predictors of spatial diffusion. The standard phylogeographic generalised linear model formulation, however, assumes that rates of spatial diffusion are a noiseless deterministic function of the set of covariates, admitting no other unobserved sources of variation. Under a variety of simulation scenarios, we demonstrate that the lack of a term modelling stochastic noise results in high false positive rates for predictors of spatial diffusion. We further show that the false positive rate can be controlled by including a random effect term, thus allowing unobserved sources of rate variation. Finally, we apply this random effects model to three recently published datasets and contrast the results of analysing these datasets with those obtained using the standard model. Our study demonstrates the prevalence of false positive results for predictors under the standard phylogeographic model in multiple simulation scenarios and, using empirical data from the literature, highlights the importance of a model accounting for random variation.
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Park, Jin Won. "Simulation optimization with discrete decision variables and a single linear constraint /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487329662145114.
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Kamali, Aslan. "Developing a Decision Making Approach for District Cooling Systems Design using Multi-objective Optimization." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-208228.
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Energy consumption rates have been dramatically increasing on a global scale within the last few decades. A significant role in this increase is subjected by the recent high temperature levels especially at summer time which caused a rapid increase in the air conditioning demands. Such phenomena can be clearly observed in developing countries, especially those in hot climate regions, where people depend mainly on conventional air conditioning systems. These systems often show poor performance and thus negatively impact the environment which in turn contributes to global warming phenomena. In recent years, the demand for urban or district cooling technologies and networks has been increasing significantly as an alternative to conventional systems due to their higher efficiency and improved ecological impact. However, to obtain an efficient design for district cooling systems is a complex task that requires considering a wide range of cooling technologies, various network layout configuration possibilities, and several energy resources to be integrated. Thus, critical decisions have to be made regarding a variety of opportunities, options and technologies. The main objective of this thesis is to develop a tool to obtain preliminary design configurations and operation patterns for district cooling energy systems by performing roughly detailed optimizations and further, to introduce a decision-making approach to help decision makers in evaluating the economic aspects and environmental performance of urban cooling systems at an early design stage. Different aspects of the subject have been investigated in the literature by several researchers. A brief survey of the state of the art was carried out and revealed that mathematical programming models were the most common and successful technique for configuring and designing cooling systems for urban areas. As an outcome of the survey, multi objective optimization models were decided to be utilized to support the decision-making process. Hence, a multi objective optimization model has been developed to address the complicated issue of decision-making when designing a cooling system for an urban area or district. The model aims to optimize several elements of a cooling system such as: cooling network, cooling technologies, capacity and location of system equipment. In addition, various energy resources have been taken into consideration as well as different solar technologies such as: trough solar concentrators, vacuum solar collectors and PV panels. The model was developed based on the mixed integer linear programming method (MILP) and implemented using GAMS language. Two case studies were investigated using the developed model. The first case study consists of seven buildings representing a residential district while the second case study was a university campus district dominated by non-residential buildings. The study was carried out for several groups of scenarios investigating certain design parameters and operation conditions such as: Available area, production plant location, cold storage location constraints, piping prices, investment cost, constant and variable electricity tariffs, solar energy integration policy, waste heat availability, load shifting strategies, and the effect of outdoor temperature in hot regions on the district cooling system performance. The investigation consisted of three stages, with total annual cost and CO2 emissions being the first and second single objective optimization stages. The third stage was a multi objective optimization combining the earlier two single objectives. Later on, non-dominated solutions, i.e. Pareto solutions, were generated by obtaining several multi objective optimization scenarios based on the decision-makers’ preferences. Eventually, a decision-making approach was developed to help decision-makers in selecting a specific solution that best fits the designers’ or decision makers’ desires, based on the difference between the Utopia and Nadir values, i.e. total annual cost and CO2 emissions obtained at the single optimization stagesDie Energieverbrauchsraten haben in den letzten Jahrzehnten auf globaler Ebene dramatisch zugenommen. Diese Erhöhung ist zu einem großen Teil in den jüngst hohen Temperaturniveaus, vor allem in der Sommerzeit, begründet, die einen starken Anstieg der Nachfrage nach Klimaanlagen verursachen. Solche Ereignisse sind deutlich in Entwicklungsländern zu beobachten, vor allem in heißen Klimaregionen, wo Menschen vor allem konventionelle Klimaanlagensysteme benutzen. Diese Systeme verfügen meist über eine ineffiziente Leistungsfähigkeit und wirken sich somit negativ auf die Umwelt aus, was wiederum zur globalen Erwärmung beiträgt. In den letzten Jahren ist die Nachfrage nach Stadt- oder Fernkältetechnologien und -Netzwerken als Alternative zu konventionellen Systemen aufgrund ihrer höheren Effizienz und besseren ökologischen Verträglichkeit satrk gestiegen. Ein effizientes Design für Fernkühlsysteme zu erhalten, ist allerdings eine komplexe Aufgabe, die die Integration einer breite Palette von Kühltechnologien, verschiedener Konfigurationsmöglichkeiten von Netzwerk-Layouts und unterschiedlicher Energiequellen erfordert. Hierfür ist das Treffen kritischer Entscheidungen hinsichtlich einer Vielzahl von Möglichkeiten, Optionen und Technologien unabdingbar. Das Hauptziel dieser Arbeit ist es, ein Werkzeug zu entwickeln, das vorläufige Design-Konfigurationen und Betriebsmuster für Fernkälteenergiesysteme liefert, indem aureichend detaillierte Optimierungen durchgeführt werden. Zudem soll auch ein Ansatz zur Entscheidungsfindung vorgestellt werden, der Entscheidungsträger in einem frühen Planungsstadium bei der Bewertung städtischer Kühlungssysteme hinsichtlich der wirtschaftlichen Aspekte und Umweltleistung unterstützen soll. Unterschiedliche Aspekte dieser Problemstellung wurden in der Literatur von verschiedenen Forschern untersucht. Eine kurze Analyse des derzeitigen Stands der Technik ergab, dass mathematische Programmiermodelle die am weitesten verbreitete und erfolgreichste Methode für die Konfiguration und Gestaltung von Kühlsystemen für städtische Gebiete sind. Ein weiteres Ergebnis der Analyse war die Festlegung von Mehrzieloptimierungs-Modelles für die Unterstützung des Entscheidungsprozesses. Darauf basierend wurde im Rahmen der vorliegenden Arbeit ein Mehrzieloptimierungs-Modell für die Lösung des komplexen Entscheidungsfindungsprozesses bei der Gestaltung eines Kühlsystems für ein Stadtgebiet oder einen Bezirk entwickelt. Das Modell zielt darauf ab, mehrere Elemente des Kühlsystems zu optimieren, wie beispielsweise Kühlnetzwerke, Kühltechnologien sowie Kapazität und Lage der Systemtechnik. Zusätzlich werden verschiedene Energiequellen, auch solare wie Solarkonzentratoren, Vakuum-Solarkollektoren und PV-Module, berücksichtigt. Das Modell wurde auf Basis der gemischt-ganzzahlig linearen Optimierung (MILP) entwickelt und in GAMS Sprache implementiert. Zwei Fallstudien wurden mit dem entwickelten Modell untersucht. Die erste Fallstudie besteht aus sieben Gebäuden, die ein Wohnviertel darstellen, während die zweite Fallstudie einen Universitätscampus dominiert von Nichtwohngebäuden repräsentiert. Die Untersuchung wurde für mehrere Gruppen von Szenarien durchgeführt, wobei bestimmte Designparameter und Betriebsbedingungen überprüft werden, wie zum Beispiel die zur Verfügung stehende Fläche, Lage der Kühlanlage, örtliche Restriktionen der Kältespeicherung, Rohrpreise, Investitionskosten, konstante und variable Stromtarife, Strategie zur Einbindung der Solarenergie, Verfügbarkeit von Abwärme, Strategien der Lastenverschiebung, und die Wirkung der Außentemperatur in heißen Regionen auf die Leistung des Kühlsystems. Die Untersuchung bestand aus drei Stufen, wobei die jährlichen Gesamtkosten und die CO2-Emissionen die erste und zweite Einzelzieloptimierungsstufe darstellen. Die dritte Stufe war ein Pareto-Optimierung, die die beiden ersten Ziele kombiniert. Im Anschluss wurden nicht-dominante Lösungen, also Pareto-Lösungen, erzeugt, indem mehrere Pareto-Optimierungs-Szenarien basierend auf den Präferenzen der Entscheidungsträger abgebildet wurden. Schließlich wurde ein Ansatz zur Entscheidungsfindung entwickelt, um Entscheidungsträger bei der Auswahl einer bestimmten Lösung zu unterstützen, die am besten den Präferenzen des Planers oder des Entscheidungsträgers enstpricht, basierend auf der Differenz der Utopia und Nadir Werte, d.h. der jährlichen Gesamtkosten und CO2-Emissionen, die Ergebnis der einzelnen Optimierungsstufen sind
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Chan, Ka Hou. "Bayesian methods for solving linear systems." Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493250.
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Tandberg, Caroline, and Signy Elde Vefring. "The linear decision rule approach applied to the hydrothermal generation planning problem." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for industriell økonomi og teknologiledelse, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-20963.
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We use the linear decision rule approach to develop a model for a stochastic multi-stage generation planning problem in the Nordic region. By developing both the primal and the dual versions of the program, the loss of optimality incurred by the linear decision rule approach can be estimated. Uncertain parameters take values in an uncertainty set defined by upper and lower bounds. Alternative modelling methods for stochastic problems of comparable size and structure either suffer from the curse of dimensionality, or have to rely on unrealistic simplifying assumptions to achieve tractability. We show that the linear decision rule approach gives a good trade-off between tractability and accuracy for a stochastic generation planning problem.
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Rodgers, Philip D. "A linear programming based decision support aid for Navy enlisted strength planning." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/43744.
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Approved for public release; distribution is unlimitedA multi-objective linear program (MOLP) using goal programming is developed as a decision support aid in determining optimal levels of those areas of Navy enlisted strength planning which are subject to centralized management control. Over a multi-year period these decisions include monthly inventories in each paygrade, monthly total inventories, monthly advancements in the top six paygrades, and monthly recruiting goals. The model incorporates the various budgetary, Congressional, and internal Navy force structure constraints inherent in the strength planning process while minimizing deviations from desired inventory goals, ensuring inventory stability, and determining optimal recruiting goals.
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Anderson, Russell Kay. "Decision support for multi-objective linear programming using an interactive graphic presentation." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186950.
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Many decisions in real world applications are based on conflicting criteria or objectives. In order to improve one objective, it is necessary to sacrifice another. Linear programming has long been used to optimize a single objective. When a linear programming problem involves multiple objectives (MOLP), it is usually not possible to locate a single solution that simultaneously optimizes all objectives. Hence, a methodology is needed to help the decision maker (DM) explore the space of feasible solutions in order to locate an acceptable compromise solution. An interactive approach that supports the DM in the exploration process is presented. The methodology is implemented on a microcomputer running a graphical user interface. The computations are based on an expansion of the Dror-Gass (1987) methodology in which candidate solutions are located using weak order preferences for variables and objectives. It differs from previous methodologies in that it does not require burdensome trade-off ratios or strength of preference comparisons. During exploration, the DM is presented a multi-faceted graphical representation of solutions for consideration. Previous studies of the effectiveness of graphics to support the decision making process have used static presentations of the data. The graphic presentation as implemented is dynamic. It makes use of animation, interactive zoom (or inspect), and interactive highlighting of the results to improve its effectiveness. In the design of the interface, special attention was paid to the requirements for supporting interaction with large LP problems. The software implementation and methodology were tested by subjects drawn from faculty and students at the University of Arizona. It was also reviewed in industry. The results are presented.
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Sohul, Munawwar Mahmud. "PERFORMANCE OF LINEAR DECISION COMBINER FOR PRIMARY USER DETECTION IN COGNITIVE RADIO." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/705.
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The successful implementation and employment of various cognitive radio services are largely dependent on the spectrum sensing performance of the cognitive radio terminals. Previous works on detection of cognitive radio have suggested the necessity of user cooperation in order to be able to detect at low signal-to-noise ratios experienced in practical situations. This report provides a brief overview of the impact of different fusion strategies on the spectrum hole detection performance of a fusion center in a distributed detection environment. Different decision or detection rule and fusion strategies, like single sensor scenario, counting rule, and linear decision metric, were used to analyze their influence on the spectrum sensing performance of the cognitive radio network. We consider a system of cognitive radio users who cooperate with each other in trying to detect licensed transmissions. Assuming that the cooperating nodes use identical energy detectors, we model the received signals as correlated log-normal random variables and study the problem of fusing the decisions made by the individual nodes. The cooperating radios were assumed to be designed in such a way that they satisfy the interference probability constraint individually. The interference probability constraint was also met at the fusion center. The simulation results strongly suggests that even when the observations at the individual sensors are moderately correlated, it is important not to ignore the correlation between the nodes for fusing the local decisions made by the secondary users. The thesis mainly focuses on the performance measurement of linear decision combiner in detecting primary users in a cognitive radio network.
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Fernandes, Carlos Alexandre Rolim. "EqualizaÃÃo adaptativa e autodidata de canais lineares e nÃo-lineares utilizando o algoritmo do mÃdulo constante." Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=2041.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoEste trabalho trata da proposiÃÃo de algoritmos para equalizaÃÃo cega de canais lineares e nÃao-lineares inspirados no Algoritmo do MÃdulo Constante (CMA). O CMA funciona de maneira bastante eficiente com constelaÃÃes nas quais todos os pontos possuem a mesma amplitude, como em modulaÃÃes do tipo Phase Shift Keying (PSK). Entretanto, quando os pontos da constelaÃÃo podem assumir diferentes valores de amplitudes, como em modulaÃÃes do tipo Quadrature Amplitude Modulation (QAM), o CMA e seus derivados muitas vezes nÃo funcionam de forma satisfatÃria. Desta forma, as tÃcnicas aqui propostas sÃo projetadas para melhorar a performance do CMA em termos de velocidade de convergÃncia e precisÃo, quando operando em sinais transmitidos com diversos mÃdulos, em particular para a modulaÃÃo QAM. Assim como o CMA, para possuir um bom apelo prÃtico, essas tÃcnicas devem apresentar bom compromisso entre complexidade, robustez e desempenho. Para tanto, as tÃcnicas propostas utilizam o Ãltimo sÃmbolo decidido para definir uma estimaÃÃo de raio de referÃncia para a saÃda do equalizador. De fato, esses algoritmos podem ser vistos como generalizaÃÃes do CMA e de alguns derivados do CMA para constelaÃÃes com mÃltiplos raios. A proposiÃÃo de algoritmos do tipo gradiente estocÃstico à concluÃda com o desenvolvimento de tÃcnicas originais, baseadas no CMA, para equalizaÃÃo de canais do tipo Wiener, que consiste em um filtro linear com memÃria, seguido por um filtro nÃo-linear sem memÃria. As expressÃes para a adaptaÃÃo do equalizador sÃo encontradas com o auxÃlio de uma notaÃÃo unificada para trÃs diferentes estruturas: i) um filtro de Hammerstein; ii) um filtro de Volterra diagonal; e iii) um filtro de Volterra completo. Um estudo teÃrico acerca do comportamento do principal algoritmo proposto, o Decision Directed Modulus Algorithm (DDMA) à realizado. SÃo analisadas a convergÃncia e a estabilidade do algoritmo atravÃs de uma anÃlise dos pontos de mÃnimo de sua funÃÃo custo. Outro objetivo à encontrar o valor teÃrico do Erro MÃdio QuadrÃtico MÃdio em Excesso - Excess Mean Square Error (EMSE) fornecido pelo DDMA considerando-se o caso sem ruÃdo. Ao final, à feito um estudo em que se constata que o algoritmo DDMA possui fortes ligaÃÃes com a soluÃÃo de Wiener e com o CMA. VersÃes normalizadas, bem como versÃes do tipo Recursive Least Squares (RLS), dos algoritmos do tipo gradiente estocÃstico estudados sÃo tambÃm desenvolvidas. Cada famÃlia de algoritmos estudada fie composta por quatro algoritmos com algumas propriedades interessantes e vantagens sobre as tÃcnicas clÃssicas, especialmente quando operando em sinais QAM de ordem elevada. TambÃm sÃo desenvolvidas versÃes normalizadas e do tipo RLS dos algoritmos do tipo CMA estudados para equalizaÃÃo de canais nÃo-lineares. O comportamento de todas as famÃlias de algoritmos desenvolvidos à testado atravÃs de simulaÃÃes computacionais, em que à verificado que as tÃcnicas propostas fornecem ganhos significativos em desempenho, em termos de velocidade de convergÃncia e erro residual, em relaÃÃo Ãs tÃcnicas clÃssicas.
This work studies and proposes algorithms to perform blind equalization of linear and nonlinear channels inspired on the Constant Modulus Algorithm (CMA). The CMA works very well for modulations in which all points of the signal constellation have the same radius, like in Phase Shift Keying (PSK) modulations. However, when the constellation points are characterized by multiple radii, like in Quadrature Amplitude Modulation (QAM) signals, the CMA does not work properly in many situations. Thus, the techniques proposed here are designed to improve the performance of the CMA, in terms of speed of convergence and residual error, when working with signals transmitted with multiple magnitude, in particular with QAM signals. As well as for the CMA, these techniques should have a good compromise among performance, complexity and robustness. To do so, the techniques use the last decided symbol to estimate reference radius to the output of the equalizer. In fact, they can be seen as modifications of the CMA and of some of its derivatives for constellations with multiple radii. The proposition of stochastic gradient algorithms is concluded with the development of new adaptive blind techniques to equalize channels with a Wiener structure. A Wiener filter consists of a linear block with memory followed by a memoryless nonlinearity, by using the CMA. We develop expressions for the adaptation of the equalizer using a unified notation for three different equalizer filter structures: i) a Hammerstein filter, ii) a diagonal Volterra filter and iii) a Volterra filter. A theoretical analysis of the main proposed technique, the Decision Directed Modulus Algorithm (DDMA), is also done. We study the convergence and the stability of the DDMA by means of an analysis of the minima of the DDM cost function. We also develop an analytic expression for the Excess Mean Square Error (EMSE) provided by the DDMA in the noiseless case. Then, we nd some interesting relationships among the DDM, the CM and the Wiener cost functions. We also develop a class of normalized algorithms and a class of Recursive Least Squares (RLS)-type algorithms for blind equalization inspired on the CMA-based techniques studied. Each family is composed of four algorithms with desirable properties and advantages over the original CM algorithms, specially when working with high-level QAM signals. Normalized and RLS techniques for equalization of Wiener channels are also developed. The behavior of the proposed classes of algorithms discussed is tested by computational simulations. We verify that the proposed techniques provide significative gains in performance, in terms of speed of convergence and residual error, when compared to the classical algorithms.
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Laing, Adam. "TLE proteins in mouse embryonic stem cell self renewal and early lineage specification." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5729.
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TLE proteins are a closely related family of vertebrate corepressors. They have no intrinsic DNA binding ability, but are recruited as transcriptional repressors by other sequence specific proteins. TLE proteins and their homologues in other species have been implicated in many developmental processes including neurogenesis, haematopoiesis and the formation of major organs. They have also been implicated in early lineage specification in vertebrates but a direct role in this has not been found in mammals. The aim of my PhD is therefore to analyse the function of TLE proteins in early lineage specification and cell fate decisions using mouse embryonic stem cells (ESCs) as a model. The investigation of this has previously been complicated, firstly by the large array of transcription factors that TLEs interact with and secondly by redundancy between similar TLE proteins hindering loss of function approaches. To circumvent these problems, I have used two complementary experimental strategies. The first was identification of point mutations in TLE1 that affect specific classes of DNA binding. Two of these mutations L743F and R534A were of particular interest and were reversibly overexpressed in ES cells to correlate phenotypes to biochemical activity. The second strategy was the mutation of the two primary TLC genes in ES cells and early mouse embryos, TLE3 and TLE4. Complementary evidence from these approaches revealed a role for TLEs in the promotion of ES cell differentiation by repression of pluripotency/self-renewal associated genes. Additionally, neural specification was increased by TLE1 expression especially by the TLE1 point mutations, highlighting opposing roles for negative effects on mesendodermal differentiation. Early mesoderm/primitive streak was increased by loss of TLE, probably through Wnt antagonism. Anterior endoderm was increased by reduced TLE, but a critical level of TLE was still necessary and TLE1 overexpression also upregulated some anterior endoderm markers suggesting both negative and positive roles for TLE proteins in this process.
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Gibbin, Randal Victor. "Modelos para escolha de cultivares em empreendimentos agricolas de pequeno porte." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263460.
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Orientador: Marcius Fabius Henriques de CarvalhoDissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Neste trabalho procurou-se desenvolver uma ferramenta de suporte à decisão para a seleção de cultivares de Citrus em uma fazenda em fase de implantação localizada em Porto Ferreira/SP. Foram utilizadas as técnicas de Programação Linear para a seleção de cultivares e a Análise de Retorno Esperado para o auxílio na determinação da estimativa de retorno do investimento. Foram determinadas sugestões de ocupação do empreendimento através de três modelos em programação linear, dos quais um foi desenvolvido em programação inteira, os modelos trabalharam com sete cultivares de Citrus desempenhando o papel de variáveis e com restrições de investimento total em insumos, mão-de-obra e área de plantio. Foi realizada uma análise da demanda de laranja de mesa no Estado de São Paulo, determinando-se a equação de regressão descrevendo seu comportamento, a partir desta análise foi construída uma distribuição de probabilidade de demanda de laranja de mesa para o Estado de São Paulo e para o empreendimento, objeto de estudo. A partir destes resultados foi gerada a curva de retorno esperado do empreendimento para a construção de cenários de retorno do investimento. Este trabalho demonstrou a facilidade de aplicação das ferramentas utilizadas em empreendimentos de pequeno porte, fornecendo subsídios para decisões do investidor
Abstract: This investigation describes a set of models to support the decision of a citrus variety selection for an agricultural enterprise located at Porto Ferreira/SP. To achieve this goal were applied the Linear Programming and Expected Return Analysis techniques. By the use of three linear programming models, one of them developed on Integer Programming, were considered seven citrus varieties as decision variables and three constraints: total investment in agro-chemicals, labor and area; the models provided suggestions of land occupation. By the analysis of historical information regarding Citrus production in São Paulo Estate, was developed a Expected Return Analysis for the Citrus production in São Paulo Estate and for the enterprise as well, focused on return on investment. The results obtained from this investigation are important to describe a methodology for supporting the investor decision making process in small agricultural business, due to the easy application of the techniques
Mestrado
Planejamento e Gestão Estrategica da Manufatura
Mestre Profissional em Engenharia Mecanica
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Fallon, John E. "Naval Fuel Management System (NFMS) a decision support system for a limited resource." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5166.
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Approved for public release; distribution is unlimitedIncludes supplemental material, embedded in this pdf. See page 46 of document to read instructions for accessing supplemental material.
The fuel planning for U.S. Naval operations at sea is reactive and relies upon pen and paper calculations. Decisions on where and when to refuel are complex and need a Decision Support System (DSS) to help planners maximize the benefits of the limited fuel resource. This thesis defines requirements and outlines a feasible design to develop a Naval Fuel Management System (NFMS). The variables that fuel planning rely upon are not just ship course and speed, but also the weather at the time a ship travels through a particular area. The most efficient plant configuration plays a factor in the fuel plan as well. Additionally, there are numerous ports and oilers available at any given time. Up-to-date accurate weather forecast databases are available, predicting currents and winds, which will affect the ship in the future. Fuel burn charts have been developed for each ship class outlining the most efficient plant configuration for given speeds. Transportation analysis has shown that an optimal path exists for this class of complex problems. By combining these technologies into one system, an application can be developed to accurately plan fueling operations in the future, making Navy refueling more efficient.
US Navy (USN) author
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Bergert, Franklin Bryan. "Using response time to distinguish between lexicographic and linear models of decision making." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3297942.
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Thesis (Ph.D.)--Indiana University, Dept. of Psychological and Brain Sciences and Program in Neuroscience Dept., 2008.Title from dissertation home page (viewed Sept. 30, 2008). Source: Dissertation Abstracts International, Volume: 69-03, Section: B, page: 1980. Adviser: Robert M. Nosofsky.
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Collison, Sean Michael. "Extending the Dorsch decoder for efficient soft decision decoding of linear block codes." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Spring2009/s_collison_042309.pdf.
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Thesis (M.S. in computer engineering)--Washington State University, May 2009.Title from PDF title page (viewed on May 21, 2009). "School of Electrical Engineering and Computer Science." Includes bibliographical references (p. 64-65).
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Angel, N. Faye. "Collaborative Study and Paired Test Taking in Collegiate Level Linear Programming Instruction." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30746.
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The purpose of this investigation was to examine the effects of collaborative learning strategies on formulating solutions to linear programming word problems that were designed to incorporate problem-solving skills. Forty-six students majoring in business at a small southwest college in Virginia participated in the study. After an instruction session, a study period, and a question and answer discussion, participants completed the test instrument based upon random assignment to three treatment groups. These included individual study with individual test taking (control), paired study with individual test taking, and paired study with paired test taking. All participants returned in 17 days to complete a posttest individually having received no further instruction in linear programming theory.
The following null hypothesis was examined: No differences in treatment means measuring problem-solving abilities would be found based on students' test and posttest scores using two treatment groups of collaborative study, with collaborative or individual test taking, and a control group of individual study with individual test taking. After satisfying the assumptions of no difference in ability in the treatment groups, establishing significant influence of ability on test score and posttest score variables, and establishing homogeneity of regression, an analysis of covariance (ANCOVA) was used to test the null hypothesis. The null hypothesis was rejected. Treatment had a significant effect on the variance for the test score variable, F = 3.92, p < .05, and for the posttest score variable, F = 4.44, p < .05. Newman-Keuls post hoc test showed significant differences in the adjusted means of the test score variable between the individual study with individual test taking group (72.22) and the paired study with paired test taking group (87.86). For the posttest score variable, the Newman-Keuls post hoc test revealed significant differences between the adjusted means of the individual study with individual test taking group (36.25) and the paired study with individual test taking group (59.20), and between the adjusted means of the individual study with individual test taking group (36.25) and the paired study with paired test taking group (55.77). Implications of findings and recommendations for further research were discussed.Ph. D.
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MELO, Milton Perceus Santos de. "Programação linear e simulação multidimensional no mercado financeiro e commodities." Universidade Federal Rural de Pernambuco, 2012. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5222.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Usually after planting, the agricultural property attempts to assess the operational performance of the previous years through studies in order to face posteriorly a new period of activities with the beginning of a new crop. The results led the landowners to create expectations about the expansion or reduction of crops, staff hiring, supply purchasing and new investments. All these questions are relevant deriving from climatic variations, pest manifestations and from fluctuations in the economy which directly influence in the the prices of the agricultural products. However the producers face the need of making decisions which often completely change the operating process of production. In large scale these decisions influence directly the supply and the price of the products. Having in consideration that the techniques used in agricultural planning are of great value for the producers, a decision aid methodology which considers the risks in the process is applied on the spot market of agricultural commodities in order to provide the best combination of variables aiming the profit optimization. Therefore, in this it was jointly used simulation technique and linear programming taking into account the existent correlations between the coefficients of the model. The data were obtained from historic trends regarding the monthly average price of 44 agricultural commodities commercialized in the European spot market since January 1960 till September 2011. Regarding the computational part, it was used the software SAS, version 5.2. By applying the proposed method the results show that the use of simulation without dependence did not underestimate the risk when compared to the simulation with dependence and they also show that the technique did not allow the perception of the best moment to make the investment, yet fully satisfactory as a decision support tool.
Comumente após o plantio, a propriedade agrícola tenta avaliar o desempenho operacional dos anos anteriores através de estudos para posteriormente enfrentar um novo período de atividades com o início de uma nova safra. Os resultados levam os proprietários agrícolas a criar expectativas em torno de expansão ou redução de culturas, contratação de pessoal, compra de insumos e a novos investimentos. Todas estas indagações são pertinentes, provenientes de variações climáticas, manifestações de pragas e oscilações na economia que influenciam diretamente no preço dos produtos agrícolas. Contudo, os produtores deparam-se com a necessidade de tomar decisões que, muitas vezes, alteram completamente o processo operacional da produção. Em larga escala, estas decisões influenciam diretamente na oferta e no preço dos produtos. Entendendo que as técnicas utilizadas no planejamento agrícola são de grande valia para os produtores, uma metodologia de auxílio à decisão que consideram os riscos presentes no processo é aplicada no mercado à vista de commodities agrícolas com o objetivo de fornecer a melhor combinação de variáveis visando à otimização do lucro. Portanto, nesta dissertação foi utilizada uma técnica de simulação e programação linear, conjuntamente, levando em consideração as correlações existentes entre os coeficientes do modelo. Os dados foram obtidos de séries históricas referentes ao preço médio mensal de 44 commodities agrícolas comercializadas no mercado europeu à vista no período de janeiro de 1960 a setembro de 2011. Quanto à parte computacional, foi utilizado o software SAS, versão 9.2. Com a aplicação do método proposto, os resultados encontrados mostram que o uso da simulação sem dependência não subestimou o risco quando comparado à simulação com dependência e que a técnica não possibilitou a percepção do melhor momento para realizar o investimento, no entanto plenamente satisfatória como ferramenta de suporte à decisão.
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Curtis, S. McKay. "The "fair" triathlon : equating standard deviations using non-linear Bayesian models /." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd428.pdf.
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Chan-Taw, Stephan. "Performance of linear detectors using partial decision techniques in CDMA systems with multiple antenna." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27615.
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Partial decision variables exploit the code diversity available in a code division multiple access system by detecting the received signal over different portions of the signaling interval to produce multiple decision intervals. Decision variables can then be weighted using adaptive filtering techniques, improving signal to interference plus noise ratio. In this thesis, we integrate the partial decision variable technique with multiple antennas to further improve performance by exploiting spatial diversity without greatly increasing the complexity of the system. Specifically, we will demonstrate the use of the partial decision variable technique through simulated and measured channel data for different configurations of single and multiple antenna system with least mean square weighting. Further, a multiuser detection technique using partial decision variables is developed for space-code division multiple access which significantly reduces the effects of multi-access and self interference to provide good performance with low incremental complexity. Throughout this thesis we will show using simulations and discussion that the use of multiple partial decision variables provide better BER performance over single decision variable systems at higher signal to noise ratios. Overall the use of multiple PDV with properly chosen least mean square step sizes, can provide additional gain with relatively low increase in complexity.
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鄧沛權 and Pui-kuen Tang. "Bayesian analysis of errors-in-variables in generalized linear models." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31232802.
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Tang, Pui-kuen. "Bayesian analysis of errors-in-variables in generalized linear models /." [Hong Kong : University of Hong Kong], 1992. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1325330X.
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LoPinto, Frank Anthony. "An Agent-Based Distributed Decision Support System Framework for Mediated Negotiation." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/27401.
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Implementing an e-market for limited supply perishable asset (LiSPA) products is a problem at the intersection of online purchasing and distributed decision support systems (DistDSS). In this dissertation, we introduce and define LiSPA products, provide real-world examples, develop a framework for a distributed system to implement an e-market for LiSPA products, and provide proof-of-concept for the two major components of the framework.
The DistDSS framework requires customers to instantiate agents that learn their preferences and evaluate products on their behalf. Accurately eliciting and modeling customer preferences in a quick and easy manner is a major hurdle for implementing this agent-based system. A methodology is developed for this problem using conjoint analysis and neural networks.
The framework also contains a model component that is addressed in this work. The model component is presented as a mediator of customer negotiation that uses the agent-based preference models mentioned above and employs a linear programming model to maximize overall satisfaction of the total market.Ph. D.
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Botero, Alonso. "Sampling weak values : a non-linear Bayesian model for non-ideal quantum measurements /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Liu, Yu. "Estimation, Decision and Applications to Target Tracking." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1758.
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This dissertation mainly consists of three parts. The first part proposes generalized linear minimum mean-square error (GLMMSE) estimation for nonlinear point estimation. The second part proposes a recursive joint decision and estimation (RJDE) algorithm for joint decision and estimation (JDE). The third part analyzes the performance of sequential probability ratio test (SPRT) when the log-likelihood ratios (LLR) are independent but not identically distributed.
The linear minimum mean-square error (LMMSE) estimation plays an important role in nonlinear estimation. It searches for the best estimator in the set of all estimators that are linear in the measurement. A GLMMSE estimation framework is proposed in this disser- tation. It employs a vector-valued measurement transform function (MTF) and finds the best estimator among all estimators that are linear in MTF. Several design guidelines for the MTF based on a numerical example were provided.
A RJDE algorithm based on a generalized Bayes risk is proposed in this dissertation for dynamic JDE problems. It is computationally efficient for dynamic problems where data are made available sequentially. Further, since existing performance measures for estimation or decision are effective to evaluate JDE algorithms, a joint performance measure is proposed for JDE algorithms for dynamic problems. The RJDE algorithm is demonstrated by applications to joint tracking and classification as well as joint tracking and detection in target tracking.
The characteristics and performance of SPRT are characterized by two important functions—operating characteristic (OC) and average sample number (ASN). These two functions have been studied extensively under the assumption of independent and identically distributed (i.i.d.) LLR, which is too stringent for many applications. This dissertation relaxes the requirement of identical distribution. Two inductive equations governing the OC and ASN are developed. Unfortunately, they have non-unique solutions in the general case. They do have unique solutions in two special cases: (a) the LLR sequence converges in distributions and (b) the LLR sequence has periodic distributions. Further, the analysis can be readily extended to evaluate the performance of the truncated SPRT and the cumulative sum test.
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Santos, Ana Paula dos. "Resolução do modelo de Li e Reeves usando programação por metas." Niterói, 2017. https://app.uff.br/riuff/handle/1/4084.
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A baixa discriminação e o esquema de multiplicadores pouco realistas são frequentemente apontadas como limitações da Análise Envoltória de Dados (DEA, de Data Envelopment Analysis). Com o propósito de amenizá-las, o modelo MCDEA (Multiple Criteria DEA) foi desenvolvido sob uma perspectiva multiobjetivo. Como na maioria dos problemas multiobjetivo, o modelo MCDEA não costuma gerar uma solução ótima única, mas um conjunto de soluções não dominadas. Buscando obter uma solução, que, tanto quanto possível, otimize conjuntamente as funções objetivo do modelo MCDEA, foram propostas abordagens baseadas na metodologia de programação por metas (GP, de Goal Programming). Dentre elas, destacam-se os modelos GPDEA, que usam programação por metas do tipo soma ponderada. Contudo, recentemente, os modelos GPDEA foram considerados inválidos, sem que nenhuma formulação alternativa baseada em programação por metas fosse proposta. Visando preencher tal lacuna, esta tese tem o objetivo de desenvolver formulações que solucionem, apropriadamente, o modelo MCDEA, para o caso de retornos constantes e variáveis de escala, mediante o uso de programação por metas do tipo soma ponderada. Essas formulações foram denominadas modelos WGP-MCDEA (Weighted GP-MCDEA), e englobam tanto a orientação a inputs como a outputs. Os modelos propostos geram as soluções básicas não dominadas dos modelos MCDEA correspondentes, quando os níveis de aspiração para as metas são precisamente definidos com este fim. Quando esses níveis são relaxados, em geral, os modelos WGP-MCDEA geram as soluções não dominadas dos modelos MCDEA correspondentes que cobrem a maior área na região de indiferença dos pesos.
Low discrimination and unrealistic multipliers schemes are often cited as limitations of DEA. To mitigate those limitations, the MCDEA model was developed under a multi-objective perspective. As in most multiple objective problems, MCDEA model does not usually result in a unique optimal solution, but in a set of non-dominated solutions. In an attempt to obtain a satisfactory solution, which, as far as possible, jointly optimizes MCDEA´s objective functions, some goal-programming-based approaches were proposed. Among those proposals, we highlight the GPDEA models, which use weighted goal programming. However, recently, GPDEA models were considered invalid, without any alternative goal-programming-based formulation being proposed. Seeking to fill this gap, the objective of this dissertation is to develop formulations that appropriately solve MCDEA model for the cases of constant and variable returns-to-scale, by means of weighted goal programming. These formulations were called WGP-MCDEA models, and include both input and output orientations. The proposed models generate the basic non-dominated solutions of the corresponding MCDEA models when the goals´ aspiration levels are specifically defined for this purpose. When those aspiration levels are smoothened, the WP-MCDEA models generally produce the non-dominated solution of the corresponding MCDEA models that cover the largest area in the indifference region.
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Oliveira, Hugo Rocha de. "Análise do aproveitamento múltiplo do reservatório de Barra Bonita - SP, através da aplicação de técnica de programação linear associada a modelo de rede de fluxo." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-09062016-093336/.
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O objeto deste trabalho é a análise do aproveitamento múltiplo do reservatório de Barra Bonita, localizado na confluência entre os rios Piracicaba e Tietê, no estado de São Paulo e pertencente ao chamado sistema Tietê-Paraná. Será realizada a otimização da operação do reservatório, através de programação linear, com o objetivo de aumentar a geração de energia elétrica, através da maximização da vazão turbinada. Em seguida, a partir dos resultados da otimização da geração de energia, serão utilizadas técnicas de simulação computacional, para se obter índices de desempenho conhecidos como confiabilidade, resiliência e vulnerabilidade, além de outros fornecidos pelo próprio modelo de simulação a ser utilizado. Estes índices auxiliam a avaliação da freqüência, magnitude e duração dos possíveis conflitos existentes. Serão analisados os possíveis conflitos entre a navegação, o armazenamento no reservatório, a geração de energia e a ocorrência de enchentes na cidade de Barra Bonita, localizada a jusante da barragem.The aim of this study is to analyze the multiple use of the Barra Bonita reservoir, which is located in the confluence of the Piracicaba river and the Tietê river, in the state of São Paulo, and belongs to the called Tietê-Paraná system. The reservoir operation will be optimized, through linear programming, aiming to increase the hydropower generation, by maximizing the water flow through turbines. In sequence, on the hydropower generation optimization results, computer simulation techniques will be used, in order to obtain performance rates as reliability, resilience and vulnerability, in addiction to other rates provided by the simulation model itself. These rates can assist to evaluate the frequency, the magnitude and the duration of possible conflicts that may occur. The navigation, the water storage in the reservoir, the hydropower generation and the occurrence of floods in Barra Bonita, a city located downstream the dam, will be analyzed.
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Mehmood, Rashid. "Fuzzy linear programming problems solved with Fuzzy decisive set method." Thesis, Blekinge Tekniska Högskola, Sektionen för ingenjörsvetenskap, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-1201.
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In the thesis, there are two kinds of fuzzy linear programming problems, one of them is a linear programming problem with fuzzy technological coefficients and the second is linear programming problem in which both the right-hand side and the technological coefficients are fuzzy numbers. I solve the fuzzy linear programming problems with fuzzy decisive set method.
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Dinger, Steven. "Essays on Reinforcement Learning with Decision Trees and Accelerated Boosting of Partially Linear Additive Models." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1562923541849035.
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Risberg, Daniel. "Robust Optimization in Seasonal Planning of Hydro Power Plants." Thesis, KTH, Optimeringslära och systemteori, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173478.
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Hydro power producers are faced with the task of releasing water from the reservoirs in the right time. To do this there are tools using stochastic optimization that aims at maximizing the income of that producer. The existing methods have a high computing time and grow exponentially with the size of the problem. A new approach that uses linear decision rules is investigated in this thesis to see if it is possible to maintain the same quality of the solutions and in the same time decrease run times. With this method the hydro power producer receives policies as an affine function of the realization of the uncertainty variables in inflow and price. This thesis presents a deterministic model and then converts it into an linear decision rules, LDR, model. It also presents a way to model the uncertainty in both inflow to the reservoir and the spot price. The result is that the LDR approach generates reasonable policies with low run times but loses a lot of optimality compared to solutions that are used today. Therefore it is concluded that this approach needs further development before commercial use. The work described in this thesis has been done in cooperation with three master students at NTNU. The approach of using linear decision rules are the same in the two projects but the differences are the models evaluated.
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Charchan, Shawn M. "Promoting mission success for the USMC Distributed Operations squad through efficient equipment selection." Thesis, Monterey, California. Naval Postgraduate School, 2006. http://hdl.handle.net/10945/2552.
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The Marine infantryman is carrying too much weight in combat. This thesis analyzes the trade-offs between individual load weights and the value that a Distributed Operations squad receives from the equipment its members carry. We use multiple objective decision analysis principles to help determine the coefficients for an integer linear programming model. The optimization model prescribes equipment assignment to individual positions that maximizes squad mission success while meeting target weights for the individual Marine. Our findings indicate that significant improvements can be made to the Marine's combat load weight and equipment composition. The optimization model provides the squad with a more efficient combination of equipment while reducing the average weight of the combat load by more than 19 percent for both the assault load and the approach march load. Also, by balancing the loads across the members of the squad, the model reduces the variation of weight across the squad positions from as much as 38 percent to less than 2 percent for all loads. By examining the trade space between equipment weight and equipment value, we assist in the creation of future Marine Corps doctrine by providing senior Marine leaders a starting point analysis for addressing this difficult problem.
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Fox, David. "Dynamic demand modelling and pricing decision support systems for petroleum." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/dynamic-demand-modelling-and-pricing-decision-support-systems-for-petroleum(2ce6efed-a7eb-4d10-b325-4d4590ba57ad).html.
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Pricing decision support systems have been developed in order to help retail companies optimise the prices they set when selling their goods and services. This research aims to enhance the essential forecasting and optimisation techniques that underlie these systems. This is first done by applying the method of Dynamic Linear Models in order to provide sales forecasts of a higher accuracy compared with current methods. Secondly, the method of Support Vector Regression is used to forecast future competitor prices. This new technique aims to produce forecasts of greater accuracy compared with the assumption currentlyused in pricing decision support systems that each competitor's price will simply remain unchanged. Thirdly, when competitor prices aren't forecasted, a new pricing optimisation technique is presented which provides the highest guaranteed profit. Existing pricing decision support systems optimise price assuming that competitor prices will remain unchanged but this optimisation can't be trusted since competitor prices are never actually forecasted. Finally, when competitor prices are forecasted, an exhaustive search of a game-tree is presented as a new way to optimise a retailer's price. This optimisation incorporates future competitor price moves, something which is vital when analysing the success of a pricing strategy but is absent from current pricing decision support systems. Each approach is applied to the forecasting and optimisation of daily retail vehicle fuel pricing using real commercial data, showing the improved results in each case.
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Zhou, Yifan. "Asset life prediction and maintenance decision-making using a non-linear non-Gaussian state space model." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/41696/1/Yifan_Zhou_Thesis.pdf.
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Estimating and predicting degradation processes of engineering assets is crucial for reducing the cost and insuring the productivity of enterprises. Assisted by modern condition monitoring (CM) technologies, most asset degradation processes can be revealed by various degradation indicators extracted from CM data. Maintenance strategies developed using these degradation indicators (i.e. condition-based maintenance) are more cost-effective, because unnecessary maintenance activities are avoided when an asset is still in a decent health state. A practical difficulty in condition-based maintenance (CBM) is that degradation indicators extracted from CM data can only partially reveal asset health states in most situations. Underestimating this uncertainty in relationships between degradation indicators and health states can cause excessive false alarms or failures without pre-alarms. The state space model provides an efficient approach to describe a degradation process using these indicators that can only partially reveal health states. However, existing state space models that describe asset degradation processes largely depend on assumptions such as, discrete time, discrete state, linearity, and Gaussianity. The discrete time assumption requires that failures and inspections only happen at fixed intervals. The discrete state assumption entails discretising continuous degradation indicators, which requires expert knowledge and often introduces additional errors. The linear and Gaussian assumptions are not consistent with nonlinear and irreversible degradation processes in most engineering assets. This research proposes a Gamma-based state space model that does not have discrete time, discrete state, linear and Gaussian assumptions to model partially observable degradation processes. Monte Carlo-based algorithms are developed to estimate model parameters and asset remaining useful lives. In addition, this research also develops a continuous state partially observable semi-Markov decision process (POSMDP) to model a degradation process that follows the Gamma-based state space model and is under various maintenance strategies. Optimal maintenance strategies are obtained by solving the POSMDP. Simulation studies through the MATLAB are performed; case studies using the data from an accelerated life test of a gearbox and a liquefied natural gas industry are also conducted. The results show that the proposed Monte Carlo-based EM algorithm can estimate model parameters accurately. The results also show that the proposed Gamma-based state space model have better fitness result than linear and Gaussian state space models when used to process monotonically increasing degradation data in the accelerated life test of a gear box. Furthermore, both simulation studies and case studies show that the prediction algorithm based on the Gamma-based state space model can identify the mean value and confidence interval of asset remaining useful lives accurately. In addition, the simulation study shows that the proposed maintenance strategy optimisation method based on the POSMDP is more flexible than that assumes a predetermined strategy structure and uses the renewal theory. Moreover, the simulation study also shows that the proposed maintenance optimisation method can obtain more cost-effective strategies than a recently published maintenance strategy optimisation method by optimising the next maintenance activity and the waiting time till the next maintenance activity simultaneously.
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Panchenko, Evgeny. "Sustainable Planning of Linear Infrastructure Corridor in Remote Areas." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1542777301682337.
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Caetani, Alberto Pavlick. "Uso de método multicritério para seleção de estratégia de reconversão industrial em uma refinaria de petróleo." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/101513.
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Este trabalho apresenta o processo de seleção de estratégia de reconversão industrial de uma pequena refinaria de petróleo no Sul do Brasil através da aplicação de uma modelagem integrada, utilizando um método multicriterial e programação matemática. Neste estudo foram identificadas linhas de negócio potencialmente aplicáveis à realidade da companhia e definido um conjunto de critérios de análise abrangendo as três dimensões da sustentabilidade empresarial: econômica, social e ambiental. Com base na avaliação da importância relativa de cada critério, atribuída por um grupo de decisores, e no desempenho das linhas de negócio em cada um dos critérios, foi aplicado método fuzzy TOPSIS para análise e ordenação das linhas de negócio. As informações resultantes desta análise, juntamente com dados econômicos objetivos, foram utilizadas em um modelo de programação linear inteira para avaliar portfólios viáveis de linhas de negócio, identificando estratégias candidatas à implementação na refinaria. O desempenho global de cada estratégia candidata, obtido mediante agregação dos desempenhos individuais das linhas de negócio e calculado conforme método fuzzy TOPSIS, foi analisado através de ferramentas gráficas, de modo a gerar elementos para subsidiar a seleção da melhor estratégia de reconversão. Os resultados obtidos demonstraram a eficiência da abordagem proposta, no sentido de facilitar o entendimento e a exploração da situação problema e, assim, oferecer um adequado suporte à tomada de decisão.This dissertation presents a selection process of industrial reconversion strategy in a small oil refinery in southern Brazil by applying an integrated modeling approach, using a multicriteria and a mathematical programming method. Potentially performing business lines were identified, as well a set of criteria covering the three dimensions of corporate sustainability: economic, social and environmental. Based on the relative importance evaluation of each criteria given by a group of decision-makers, and on performance of the business lines in each of the criteria, fuzzy TOPSIS method was applied for analysis and sorting of business lines. The information resulting from this analysis, along with objective economic data, were used in integer linear programming model to evaluate effective portfolios of business lines, identifying candidate strategies to implement in the refinery. Fuzzy TOPSIS is used to generate overall performance scores of each candidate strategy, aggregating the individual performance of the business lines. The sustainability assessment was analyzed through graphical tools in order to generate information to support the selection of the best strategy for the industrial reconversion. The results demonstrated the efficiency of the proposed approach to facilitate the understanding and exploitation of the problem situation and thus offer adequate support to decision making.
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Spak, Marcia Danieli Szeremeta. "Proposta de uma metodologia de apoio à tomada de decisão para a localização de centros de distribuição no setor varejista de móveis e eletrodomésticos." Universidade Tecnológica Federal do Paraná, 2012. http://repositorio.utfpr.edu.br/jspui/handle/1/604.
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O setor varejista de móveis e eletrodomésticos encontra-se em expansão e é diretamente afetado pela competividade do mercado. As empresas do setor buscam constantemente a redução dos preços e dos prazos de entrega dos produtos, para manterem a sua posição perante os concorrentes. Um dos fatores que influenciam diretamente a competitividade dessas organizações são os elevados custos do sistema de distribuição. A fim de reduzir os impactos no sistema de distribuição, o presente estudo teve por objetivo propor um modelo de apoio à tomada de decisão para a localização de centros de distribuição no setor varejista de móveis e eletrodomésticos. O trabalho foi dividido em três etapas para a sua concepção. Na primeira etapa utilizou-se um modelo por programação não-linear para definir um ponto ótimo na região abordada no estudo e posteriormente foram identificadas cinco cidades em torno desse ponto ótimo. A segunda etapa foi composta pela definição dos critérios e subcritérios influentes na decisão, e pela aplicação do método AHP para a seleção da melhor cidade para a instalação do centro de distribuição. Na terceira etapa buscou-se identificar o melhor terreno entre três alternativas, que foram avaliadas pelo método AHP a partir da definição dos critérios e subcritérios voltados a esse contexto de decisão. Os resultados apresentados mostram que o fator transporte e mercado são os principais responsáveis para a escolha da cidade, e a instalação e acessibilidade para a localização do terreno. O estudo identificou a alternativa Arapongas como a melhor cidade e o terreno três como o melhor local para a instalação do centro de distribuição.The retail sector of furniture and appliances is in expansion and is directly affected by market competitiveness. The Companies in this sector are constantly seeking reduction of prices and delivery times of products, to maintain their position before competitors. One of the factors that directly influence the competitiveness of these organizations are the high costs of the distribution system. In order to reduce the impacts on the distribution system, the present study aimed to propose a model to support decision making for the location of distribution centers in the retail sector of furniture and appliances. The work divided into three stages for its conception. In the first stage was used a non-linear programming model to define an optimal point in the region covered in the study and subsequently been identified five cities around that optimal point. The second stage was composed by defining criteria and sub-criteria that influence the decision, and the application of AHP method for selecting the best city for installing the distribution center. In the third stage is sought to identify the best ground among three alternatives, that been evaluated by AHP method from the definition of criteria and sub-criteria directed this decision context. The result show that the factor transport and market are mainly responsible for choosing the city, and the installation and accessibility to the location of the ground. The study identified the alternative Arapongas as the best city and the ground 3 as the best place to install the distribution center.