Recent technological advances and pervasiveness of wireless communication devices have offered novel and promising solutions to the road safety problem and on-the-go entertainment. One such solution is the Inter-Vehicular Communications (IVC) where vehicles cooperate in receiving and delivering the messages to each other, establishing a decentralized communication system. The communication between vehicles can be made more effective and reliable at the physical layer by using the concept of space-time coding (STC). STC demonstrated that the deployment of multiple antennas at the transmitter allows for simultaneous increase in throughput and reliability because of the additional degree of freedom offered by the spatial dimension of the wireless. However, the use of multiple antenna at the receiver is not feasible because of the size and power limitations. Cooperative diversity, which is also known as user cooperation is ideal to overcome these limitations by introducing a new concept of using the antenna of neighboring node. This technique exploits the broadcast nature of wireless transmissions and creates a virtual (distributed) antenna array through cooperating nodes to realize spatial diversity advantage. Although there has been a growing literature on cooperative diversity, the current literature is mainly limited to Rayleigh fading channel model which typically assumes a wireless communication scenario with a stationary base station antenna above roof-top level and a mobile station at street level. In this thesis, we investigate cooperative diversity for inter-vehicular communication based on cascaded Rayleigh fading. This channel model provides a realistic description of inter-vehicular channel where two or more independent Rayleigh fading processes are assumed to be generated by independent groups of scatters around the two mobile terminals. We investigate the performance of amplify-and-forward relaying for an inter-vehicular cooperative scheme assisted by either a road-side access point or another vehicle which acts as a relay. Our diversity analysis reveals that the cooperative scheme is able to extract the full distributed spatial diversity. We further formulate a power allocation problem for the considered scheme to optimize the power allocated to broadcasting and relaying phases. Performance gains up to 3 dB are obtained through optimum power allocation depending on the relay location.

Recent technological advances and pervasiveness of wireless communication devices have offered novel and promising solutions to the road safety problem and on-the-go entertainment. One such solution is the Inter-Vehicular Communications (IVC) where vehicles cooperate in receiving and delivering the messages to each other, establishing a decentralized communication system. The communication between vehicles can be made more effective and reliable at the physical layer by using the concept of space-time coding (STC). STC demonstrated that the deployment of multiple antennas at the transmitter allows for simultaneous increase in throughput and reliability because of the additional degree of freedom offered by the spatial dimension of the wireless. However, the use of multiple antenna at the receiver is not feasible because of the size and power limitations. Cooperative diversity, which is also known as user cooperation is ideal to overcome these limitations by introducing a new concept of using the antenna of neighboring node. This technique exploits the broadcast nature of wireless transmissions and creates a virtual (distributed) antenna array through cooperating nodes to realize spatial diversity advantage. Although there has been a growing literature on cooperative diversity, the current literature is mainly limited to Rayleigh fading channel model which typically assumes a wireless communication scenario with a stationary base station antenna above roof-top level and a mobile station at street level. In this thesis, we investigate cooperative diversity for inter-vehicular communication based on cascaded Rayleigh fading. This channel model provides a realistic description of inter-vehicular channel where two or more independent Rayleigh fading processes are assumed to be generated by independent groups of scatters around the two mobile terminals. We investigate the performance of amplify-and-forward relaying for an inter-vehicular cooperative scheme assisted by either a road-side access point or another vehicle which acts as a relay. Our diversity analysis reveals that the cooperative scheme is able to extract the full distributed spatial diversity. We further formulate a power allocation problem for the considered scheme to optimize the power allocated to broadcasting and relaying phases. Performance gains up to 3 dB are obtained through optimum power allocation depending on the relay location.

In this thesis, pairwise multiple comparisons and multiple comparisons with a control are studied when the observations have short-tailed symmetric distributions. Under non-normality, the testing procedure is given and Huber estimators, trimmed mean with winsorized standard deviation, modified maximum likelihood estimators and ordinary sample mean and sample variance used in this procedure are reviewed. Finally, robustness properties of the stated estimators are compared with each other and it is shown that the test based on the modified maximum likelihood estimators has better robustness properties under short-tailed symmetric distribution.

This study investigated the efficacy of the lz person fit statistic for detecting aberrant responding with unidimensional pairwise preference (UPP) measures, constructed and scored based on the Zinnes-Griggs (ZG, 1974) IRT model, which has been used for a variety of recent noncognitive testing applications. Because UPP measures are used to collect both "self-" and "other-" reports, I explored the capability of lz to detect two of the most common and potentially detrimental response sets, namely fake good and random responding. The effectiveness of lz was studied using empirical and theoretical critical values for classification, along with test length, test information, the type of statement parameters, and the percentage of items answered aberrantly (20%, 50%, 100%). We found that lz was ineffective in detecting fake good responding, with power approaching zero in the 100% aberrance conditions. However, lz was highly effective in detecting random responding, with power approaching 1.0 in long-test, high information conditions, and there was no diminution in efficacy when using marginal maximum likelihood estimates of statement parameters in place of the true values. Although using empirical critical values for classification provided slightly higher power and more accurate Type I error rates, theoretical critical values, corresponding to a standard normal distribution, provided nearly as good results.

In phylogenetic analysis, an important issue is to construct the confidence region for gene trees from DNA sequences. Usually estimation of the trees is the initial step. Maximum likelihood methods are widely applied but few tests are based on distance methods. In this thesis, we propose a new test based on balanced minimum evolution. We first examine the normality assumption of pairwise distance estimates under various model misspeci cations and also examine their variances, MSEs and squared biases. Then we compare the BME method with the WLS method in true tree reconstruction under different variance structures and model pairs. Finally, we develop a new test for finding a confidence region for the tree based on the BME method and demonstrate its effectiveness through simulation.

Aujourd'hui, les éditeurs logiciels ne conçoivent, développent et ne maintiennent plus leur offre logicielle avec comme cible un client unique. Au contraire, les offres logicielles sont conçues pour cibler plusieurs entités. Par conséquent, ces applications doivent s'intégrer dans des environnements différents et s'adapter aux besoins des clients. Ainsi, les produits logiciels développés ne sont plus des programmes uniques, mais des familles de produits. Les systèmes configurables facilitent la création de ces familles de produits. Grâce à eux il est possible de créer un produit logiciel en sélectionnant les fonctionnalités qui seront intégrées. Cependant, la validation de ces systèmes est une tâche complexe. Un système configurable peut générer plusieurs millions de configurations possibles. Il ne s'agit donc plus de valider un seul et unique produit, mais un ensemble de produits. Cet important nombre de configurations est un problème pour les personnes chargées de la validation. Nous proposons trois contributions qui visent à mieux répondre aux problématiques liées à la variabilité lors des projets de test : une présentation détaillée de deux projets de test industriels faisant face à des problématiques de variabilité issus de deux entreprises : Cisco et Orange ; une méthode originale basée sur les techniques de programmation par contraintes pour extraire des configurations de test qui respectent le critère Pairwise à partir d'un modèle explicite de la variabilité ; une comparaison de cette approche par rapport aux techniques de l'état de l'art et une étude de l'application de cette technique de test sur deux projets de tests industriels.

Na otimização de produtos e processos industriais todas as medidas de qualidade devem ser consideradas simultaneamente. No setor alimentício para a avaliação de produtos são considerados, além de medidas usuais de qualidade, dados de painéis sensoriais. Esta dissertação apresenta o estudo de um método desenvolvido especificamente em um contexto de otimização de produtos com variáveis sensoriais: o método de Comparação Indireta aos Pares (CIP). Para coleta de dados, o CIP baseia-se na comparação pareada de amostras e para análise de dados utiliza elementos do AHP (Processo Analítico Hierárquico, na sigla em inglês). Neste método, são propostas extensões com vistas a torná-lo mais confiável e aumentar sua aplicabilidade. Para atingir esse propósito são feitas adaptações em diferentes procedimentos de coleta de dados sensoriais, assim como a validação de valores de referência utilizados na análise de dados e a construção de tabelas com valores de referência para casos onde o método CIP é aplicado. As melhorias propostas no método de CIP são ilustradas através de uma aplicação prática em uma empresa alimentícia, onde, deseja-se otimizar o processo de desenvolvimento de uma barra de chocolate. O método CIP é utilizado para determinar o percentual de ingredientes utilizados na formulação da barra de chocolate. / In the optimization of products and industrial processes several quality measures must be considered simultaneously. When analyzing food products, in addition to the usual measures of quality, the performance of products as measured by a sensory panel should be also taken into account. In this thesis we analyze a method developed specifically for the optimization of products with sensory variables: the Indirect Pairwise Comparison (IPC) method. Regarding the sensory data collection the IPC is based in the pairwise comparison of samples; as for data analysis, the method uses elements of the AHP (Analytical Hierarchical Process). Extensions are proposed in the IPC in order to improve its reliability and applicability. For that matter we propose adaptations in different procedures for sensory data collection. We also validate some reference values used in the IPC’s data analysis framework and develop tables with reference values for special cases where the IPC method is applied. The proposed improvements are illustrated through a practical application in a food industry. In the case study it is desired to optimize the development of a chocolate bar. The IPC is used to determine the percentage of ingredients used in the product recipe.

For many decisions validation of their outcomes is invariably problematic to objectively assess. Therefore to aid analysis and validation of decision outcomes, approaches which provide improved traceability and more semantically meaningful measurements of the decision process are required. Hence, this research investigates traceability, transparency, interactivity and auditability to improve the decision making process. Approaches and evaluation measures are proposed to facilitate a richer decision making experience. Multi-Criteria Decision Analysis (MCDA) seeks to determine the suitability of alternatives of a goal with respect to multiple criteria. A key component of prominent MCDA methods is the concept of pairwise comparison. For a set of elements, pairwise comparison enables an accurate and transparent extraction and codification of a decision maker’s preferences, though facilitating a separation of concerns. From a set of pairwise comparisons, a ranking of the elements under consideration can be calculated. There are scenarios when a set of pairwise comparisons undergo alteration, both for individual and multiple decision makers. A set of measures of compromise are proposed to quantify the alteration that a set of pairwise comparisons undergo in such scenarios. The measures seek to provide a decision maker with meaningful knowledge regarding how their views have altered. A set of pairwise comparisons may be inconsistent. When inconsistency is present it adversely affects a ranking of the elements derived from the comparisons. Moreover inconsistency within pairwise comparisons used for consideration of more than a handful of elements is almost inevitable. Existing approaches that seek to alter a set of comparisons to reduce inconsistency lack traceability, flexibility, and specific consideration of alteration to the judgments in a way that is meaningful to a decision maker. An approach to inconsistency reduction is proposed that seeks to address these issues. For many decisions the opinions of multiple decision makers are utilized, either to avail of their combined expertise or to incorporate conflicting views. Aggregation of multiple decision makers’ pairwise companions seek to combine the views of the group into a single representation of views. An approach to group aggregation of pairwise comparisons is proposed that models compromise between the decision makers, facilitates decision maker constraints, considers inconsistency reduction during aggregation and dynamically incorporates decision maker weights of importance. With internet access becoming widespread being able to garner the views of a large group of decision makers’ views has become feasible. An approach to the aggregation of a large group of decision makers’ preferences is proposed. The approach facilitates understanding regarding both the agreement and conflict within the group during calculation of an overall group consensus. A Multi-Objective Optimisation Decision Software (MOODS) prototype tool has been developed that implements both the new measures of compromise and the proposed approaches to inconsistency reduction and group aggregation.

Na otimização de produtos e processos industriais todas as medidas de qualidade devem ser consideradas simultaneamente. No setor alimentício para a avaliação de produtos são considerados, além de medidas usuais de qualidade, dados de painéis sensoriais. Esta dissertação apresenta o estudo de um método desenvolvido especificamente em um contexto de otimização de produtos com variáveis sensoriais: o método de Comparação Indireta aos Pares (CIP). Para coleta de dados, o CIP baseia-se na comparação pareada de amostras e para análise de dados utiliza elementos do AHP (Processo Analítico Hierárquico, na sigla em inglês). Neste método, são propostas extensões com vistas a torná-lo mais confiável e aumentar sua aplicabilidade. Para atingir esse propósito são feitas adaptações em diferentes procedimentos de coleta de dados sensoriais, assim como a validação de valores de referência utilizados na análise de dados e a construção de tabelas com valores de referência para casos onde o método CIP é aplicado. As melhorias propostas no método de CIP são ilustradas através de uma aplicação prática em uma empresa alimentícia, onde, deseja-se otimizar o processo de desenvolvimento de uma barra de chocolate. O método CIP é utilizado para determinar o percentual de ingredientes utilizados na formulação da barra de chocolate. / In the optimization of products and industrial processes several quality measures must be considered simultaneously. When analyzing food products, in addition to the usual measures of quality, the performance of products as measured by a sensory panel should be also taken into account. In this thesis we analyze a method developed specifically for the optimization of products with sensory variables: the Indirect Pairwise Comparison (IPC) method. Regarding the sensory data collection the IPC is based in the pairwise comparison of samples; as for data analysis, the method uses elements of the AHP (Analytical Hierarchical Process). Extensions are proposed in the IPC in order to improve its reliability and applicability. For that matter we propose adaptations in different procedures for sensory data collection. We also validate some reference values used in the IPC’s data analysis framework and develop tables with reference values for special cases where the IPC method is applied. The proposed improvements are illustrated through a practical application in a food industry. In the case study it is desired to optimize the development of a chocolate bar. The IPC is used to determine the percentage of ingredients used in the product recipe.

Submitted by Diogo Barreiros (diogo.barreiros@ufba.br) on 2016-06-14T14:54:41Z No. of bitstreams: 1 Dissertação - Emanuele Romero.pdf: 945237 bytes, checksum: cc06b7a0943c2fe576ba1ae1ef553446 (MD5) / Approved for entry into archive by Alda Lima da Silva (sivalda@ufba.br) on 2016-06-14T15:37:04Z (GMT) No. of bitstreams: 1 Dissertação - Emanuele Romero.pdf: 945237 bytes, checksum: cc06b7a0943c2fe576ba1ae1ef553446 (MD5) / Made available in DSpace on 2016-06-14T15:37:04Z (GMT). No. of bitstreams: 1 Dissertação - Emanuele Romero.pdf: 945237 bytes, checksum: cc06b7a0943c2fe576ba1ae1ef553446 (MD5) / CAPES / O presente trabalho tem como objetivo principal apresentar a equivalência dual entre a categoria DLat, dos reticulados distributivos, e as categorias Pries, dos espaços Priestley, e Spec, dos espaços espectrais, por meio dos isomor smos entre estas últimas e a categoria PStone, dos espaços pairwise Stone; também estabelecer a equivalência dual de DLat com PStone, obtendo com isso uma alternativa para o isomor smo de Cornish. Estes isomor smos e as equivalências duais entre as referidas categorias, possibilitaram as descrições duais de alguns conceitos algébricos importantes na Teoria de Reticulados, como ltros e ideais de um reticulado. Por m, como alternativa para a dualidade de Esakia, são apresentadas dualidades bitopológicas para álgebras de Heyting. / This work aims to present the duality between the categories DLat of the distributive bounded lattices, and the categories Pries of the Priestley spaces and Spec of the spectral spaces, using isomorphisms between the last mentioned categories and the category PStone of the pairwise Stone spaces; also we establish the equivalence of DLat and PStone, receiving so an alternative for the Cornish isomorphism. These isomorphisms and the equivalencies between the above mentioned categories, make it possible to get dual descriptions of some important lattice theoretic notions, as lters and ideals of a lattice. Finally, to propose an alternative to the Esakia duality are shown bitopological dualities for Heyting algebras.