Après l'augmentation des capacités physiques des réseaux sans-fil, l'amélioration du faible rendement MAC permet aujourd'hui aux utilisateurs de bénéficier de bandes passantes inédites. Cette amélioration est notamment rendue possible par la création de systèmes d'agrégation. Or si ces systèmes permettent d'améliorer la bande passante offerte, plusieurs problématiques se posent quant à leur influence sur le comportement du système en particulier en cas de forte concurrence pour l'accès au medium. L'agrégation étudiée dans ce mémoire effectue une concaténation de plusieurs paquets dans une seule trame. Cette opération permet aux paquets de partager les en-têtes. Outre la perte de signification quant à la valeur d'un paquet, la configuration des paramètres d'un tel système reste aujourd'hui obscure pour le fournisseur d'accès. Comme les intérêts du fournisseur et de ses clients peuvent diverger, il est également nécessaire de tenir compte du compromis entre leurs exigences respectives. Afin d'adresser ces problématiques, ces travaux de thèse se concentrent sur une analyse approfondie du comportement et des implications d'un système d'agrégation de paquets (avec IEEE 802.11n pour cas d'étude). L'influence de l'agrégation sur la qualité de service offerte à une application est quantifiée au travers de plusieurs milliers de simulations effectuées avec Riverbed Modeler. Des recommandations sont ensuite proposées pour la bonne configuration du système d'agrégation dans l'optique d'optimiser les délais et l'arriéré de traitement. L'accent est mis sur les performances offertes à un flux particulier en concurrence pour le medium. Ceci dans le but de clarifier l'influence de l'agrégation sur chaque client. Cette thèse développe également un modèle analytique dudit système basé sur la théorie du calcul réseau. Les limites d'un tel modèle sont démontrées et son pessimisme est déterminé à l'aide d'une analyse fine du comportement de l'agrégation 802.11n. Cette étude démontre notamment une relative inadaptation de la théorie du calcul réseau au système d'agrégation considéré. Des ajustements de la théorie sont alors proposés, en particulier vis à vis du calcul du service rendu à un flux. Afin d'aider le fournisseur d'accès dans la configuration du système d'agrégation, cette thèse propose en dernier lieu un algorithme de configuration dynamique des paramètres d'agrégation. Cet algorithme est établi à partir des recommandations instructives établies précédemment. Son originalité repose sur la désactivation de l'agrégation en fonction de l'état des stations concurrentes. Implémenté dans Riverbed Modeler, cet algorithme montre son efficacité. De nouvelles problématiques se posent quant à son implémentation réelle (distribuée, centralisée, ...). / After the increase of the capacity of wireless networks, the improvement of the low efficiency allows users to benefit from higher bandwidths. This improvement is partly due to the creation of aggregation's systems. Now, if these systems allow to improve the offered bandwidth, several problems arise about their influence on the behavior of the system. In particular, the case of strong competition for the access to the medium remains unknown. The aggregation studied in this thesis makes a concatenation of several packets in a single frame. This operation allows the packets to share headers. Besides the loss of meaning about the value of a packet, the configuration of such a system remains today obscure for the access provider. As the interests of the provider and its customers may differ, it is also necessary to consider a compromise between their respective requirements. To address these issues, this thesis focuses on a thorough analysis of the behavior and the implications of a packet aggregation system (with IEEE 802.11n as case study). The impact of aggregation on the quality of service provided to an application is quantified through thousands of simulations with Riverbed Modeler. Recommendations are then proposed for the proper setup of the aggregation system to optimize delay and backlog. This thesis focuses on the performances offered to a particular flow in competition for the medium. Its aim is to show the influence of the aggregation on each customer. This thesis also develops an analytical model of the aggregation system using the network calculus theory. The limitations of such a model are demonstrated. Its pessimism is determined using a detailed analysis of the 802.11n aggregation. This study demonstrates a particular relative inadequacy of network calculus to the aggregation system considered. Adjustments of the theory are then proposed, particularly for the calculation of the residuel service offered to a customer. To help the access provider in the configuration of the aggregation system, this thesis lastly proposes an algorithm for a dynamic configuration of the aggregation. This algorithm is established from the recommendations previously established. Its originality is based on the deactivation of the aggregation according to the state of the competing stations. Implemented in Riverbed Modeler, this algorithm shows its efficiency. Then, new problems arise about its real implementation (distributed, centralized, ...).

La simulation est un outil puissant pour étudier les systèmes distribués. Elle permet aux chercheurs d’évaluer différents scénarios de manière reproductible, ce qui est impossible à travers des expériences réelles. Cependant, les simulations reposent souvent sur des modèles simplifiés, dont le réalisme est trop rarement étudié dans la littérature. Ceci mène à une pertinence et une applicabilité discutables des résultats obtenus. Dans ce contexte, l'objectif principal de notre travail est d'améliorer le réalisme de la simulation en mettant l'accent sur le transfert de fichiers dans un système distribué à large échelle, tel que l’infrastructure de production EGI. Le réalisme de la simulation est étudié ici au travers de deux aspects principaux : le simulateur et le modèle de plate-forme (l’infrastructure distribuée). Ensuite, à partir de simulations réalistes, nous proposons des recommandations fiables pour améliorer la gestion des fichiers à travers des portails scientifiques, tels que la plate-forme d'imagerie virtuelle (VIP). Afin de reproduire de manière réaliste les comportements du système réel en simulation, nous devons en obtenir une vue de l'intérieur. Par conséquent, nous recueillons et analysons un ensemble de traces d’exécutions d'une application particulière exécutée sur EGI via VIP. En plus des traces, nous identifions et examinons les composants du système réel à reproduire de manière réaliste en simulation. Il s’agit, par exemple, des algorithmes utilisés pour la sélection d’un réplica dans le système de production. Nous simulons ensuite ces composants en utilisant les mécanismes mis à disposition par SimGrid. Nous construisons, à partir des traces, un modèle de plate-forme réaliste essentiel à la simulation des transferts des fichiers. La précision de notre modèle de plate-forme est évaluée en confrontant les résultats de simulations avec la vérité terrain des transferts réels. Nous montrons que le modèle proposé surpasse largement le modèle issu de l’état de l’art pour reproduire la variabilité réelle des transferts de fichiers sur EGI. Ce modèle est ensuite enrichi pour permettre l’analyse de nouveaux scénarios, au-delà de la reproduction des traces d’exécution en production. Enfin, nous évaluons différentes stratégies de réplication de fichiers par simulation en utilisant deux modèles différents: un modèle issu de l’état de l’art amélioré et notre modèle de plate-forme construit à partir des traces. Les résultats de simulations montrent que les deux modèles conduisent à des décisions de réplication différentes, même s’ils reflètent une topologie de réseau hiérarchique similaire. Ceci montre que le réalisme du modèle de plateforme utilisé en simulation est essentiel pour produire des résultats pertinents et applicables aux systèmes réels. / Simulation is a powerful tool to study distributed systems. It allows researchers to evaluate different scenarios in a reproducible manner, which is hardly possible in real experiments. However, the realism of simulations is rarely investigated in the literature, leading to a questionable accuracy of the simulated metrics. In this context, the main aim of our work is to improve the realism of simulations with a focus on file transfer in a large distributed production system (i.e., the EGI federated e-Infrastructure (EGI)). Then, based on the findings obtained from realistic simulations, we can propose reliable recommendations to improve file management in the Virtual Imaging Platform (VIP). In order to realistically reproduce certain behaviors of the real system in simulation, we need to obtain an inside view of it. Therefore, we collect and analyze a set of execution traces of one particular application executed on EGI via VIP. The realism of simulations is investigated with respect to two main aspects in this thesis: the simulator and the platform model. Based on the knowledge obtained from traces, we design and implement a simulator to provide a simulated environment as close as possible to the real execution conditions for file transfers on EGI. A complete description of a realistic platform model is also built by leveraging the information registered in traces. The accuracy of our platform model is evaluated by confronting the simulation results with the ground truth of real transfers. Our proposed model is shown to largely outperform the state-of-the-art model to reproduce the real-life variability of file transfers on EGI. Finally, we cross-evaluate different file replication strategies by simulations using an enhanced state-of-the-art model and our platform model built from traces. Simulation results highlight that the instantiation of the two models leads to different qualitative decisions of replication, even though they reflect a similar hierarchical network topology. Last but not least, we find that selecting sites hosting a large number of executed jobs to replicate files is a reliable recommendation to improve file management of VIP. In addition, adopting our proposed dynamic replication strategy can further reduce the duration of file transfers except for extreme cases (very poorly connected sites) that only our proposed platform model is able to capture.

Submitted by PPG Ci?ncia da Computa??o (ppgcc@pucrs.br) on 2018-07-06T13:04:33Z No. of bitstreams: 1 WILLIAM SCHNEIDER_DIS.pdf: 3430246 bytes, checksum: 5fc61ba11d1155b509058a5d6a0c34b9 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-10T14:27:37Z (GMT) No. of bitstreams: 1 WILLIAM SCHNEIDER_DIS.pdf: 3430246 bytes, checksum: 5fc61ba11d1155b509058a5d6a0c34b9 (MD5) / Made available in DSpace on 2018-07-10T14:37:58Z (GMT). No. of bitstreams: 1 WILLIAM SCHNEIDER_DIS.pdf: 3430246 bytes, checksum: 5fc61ba11d1155b509058a5d6a0c34b9 (MD5) Previous issue date: 2014-03-13 / The increase in the number of cores available in Systems on a Chip has enabled the design of circuits with increasingly aggressive specifications. Efficient interconnection architectures such as intrachip networks are critical to the viability of these projects. However, measuring and comparing performanceof these networks for a given system is still a challenging task, which results from: (i) the complexity imposed by the abundance of available options in the design space of these networks; (ii) the current non-adoption of a unique evaluation platform to compare different networks proposals; (iii) the fact that the network traffic has a greater influence on the performance of such networks than any other design characteristic. This work has as main strategic goal the evaluation and comparison of different intrachip network architectures through the use of a unified evaluation platform. It adopts Nocbench, a recent platform, already validated in some contexts and proposed as a standard for the evaluation of intrachip networks. The employed evaluation method is based on the simulation of networks and uses as input traffic and computation models described in the form of traces, both extracted from real application. The main contributions of this work reside in: (i) the proposal of several enhancements to the chosen platform; (ii) the development of modules added to integrate the networks Hermes HS,Hermes OO, Hermes TB, Hermes VC, and YeaH from the author?s research group to the platform; (iii) the enhancement of the platform performance evaluation process, through the inclusion of metrics usually employed to compare intrachip networks, including: latency, throughput and jitter. A set of experiments validates the contributions and demonstrate the use the Nocbench platform as a useful tool in the comparison of intrachip networks of diverse origins. / O aumento no n?mero de n?cleos presentes em Sistemas Integrados em Chip tem proporcionado o projeto de circuitos com especifica??es cada vez mais agressivas. Arquiteturas de interconex?o eficientes tais como as redes intrachip s?o fundamentais para a viabilidade destes projetos. Entretanto, medir e comparar o desempenho destas redesainda ? uma tarefa desafiadora, resultado: (i) da complexidade imposta pela abund?ncia de op??es dispon?veis no espa?o de projeto destas redes; (ii) da atual n?o ado??o de uma mesma plataforma de avalia??o para a compara??o de diferentes propostas de redes; (iii) e do fato de o tr?fego de rede exercer uma influ?ncia muito maior do que qualquer caracter?stica de projeto no desempenho destas. Este trabalho tem como principal objetivo estrat?gico a avalia??o e compara??o de diferentes arquiteturas de redes intrachip atrav?s de uma plataforma de avalia??o unificada. Adota-se Nocbench, uma plataforma recente, j? validada em alguns contextos e proposta como um padr?o para a avalia??o de redes intrachip. O m?todo de avalia??o empregado baseia-se na simula??o de redes e utiliza como entrada modelos de tr?fego e de computa??o descritos sob a forma de traces, ambos extra?dos de aplica??es reais. As principais contribui??es do trabalho residem: (i) na proposta de diversas melhorias para a plataforma escolhida; (ii) no desenvolvimento de m?dulos para a integra??o das redes Hermes HS, Hermes OO, Hermes TB, Hermes VC e YeaHdo grupo de pesquisa do Autor ? plataforma em quest?o; (iii) no aprimoramento do processo de avalia??o de desempenho da plataforma, atrav?s da inclus?o de m?tricas comumente utilizadas para comparar redes intrachip, incluindo: lat?ncia, vaz?oe jitter. Um conjunto de experimentos valida as contribui??es e demonstra o uso da plataforma Nocbench como uma ferramenta ?til na compara??o de redes intrachip de origens diversas.

Made available in DSpace on 2015-12-03T18:35:07Z (GMT). No. of bitstreams: 1 Carlos_Alberto_Martins.pdf: 714359 bytes, checksum: 08b7973c087f581efc234d5addb20ef3 (MD5) Previous issue date: 2008-08-28 / The present work had as focus the evaluation of economical-financial performance of the entities belonging to the denominated Non Profit Sector, more specifically of the entities of social welfare and the need of having believable information based on an accounting system structured to sustain this evaluation, where factor as the voluntary work and the gratuitous social benefit should be treated as integral elements of the accounting bookkeeping as source of information for the administration of the entities. This dissertation is based on a study of case of an entity of social welfare, headquartered in the area of Great S??o Paulo. With base in the relative operational information to the exercises of 2004 and 2005, was measured and it was studied the economical-financial influence of the mentioned factors, in the operational structure of the entity and the need of a reliable control of the same ones in order to evidence the value transferred to the society, value this that doesn't suffer control and, so a little, disclorure, in the demonstrative ones accounting-financial. The studied problem treated of the need of a more effective control, for administration ends, of factors no documented in the way as foresees the Brazilian legislation, in order to evidence the effectiveness of the activities of an entity of social welfare. The obtained results indicate that the vision economical, financial and managerial of these entities would become more evident and interesting as social result to the investors and holders of resources destined to the welfare, what will take the a perfected revision of the control and disclosure of these factors with the creation of techniques of specific evaluation for this sector. / O presente trabalho teve como foco a avalia????o de desempenho econ??mico-financeiro das entidades pertencentes ao denominado Terceiro Setor, mais especificamente das entidades de assist??ncia social e a necessidade de se ter informa????es cr??veis baseadas em um sistema de contabiliza????o estruturado para sustentar esta avalia????o, onde fatores como o trabalho volunt??rio e as a????es gratuitas devem ser tratados como elementos integrantes da escritura????o cont??bil e como fonte de informa????es para a gest??o das entidades. Esta disserta????o est?? baseada em um estudo de caso de uma entidade de assist??ncia social, sediada na regi??o da Grande S??o Paulo. Com base nas informa????es operacionais relativas aos exerc??cios de 2004 e 2005, mensurou-se e estudou-se a influ??ncia econ??mico-financeira dos fatores citados, na estrutura operacional da entidade e a necessidade de um controle confi??vel dos mesmos a fim de evidenciar o valor transferido ?? sociedade, valor este que n??o sofre controle e, t??o pouco, evidencia????o nos demonstrativos cont??bil-financeiros. O problema estudado tratou da necessidade de um controle mais eficaz, para fins de gest??o, de fatores n??o documentados da maneira como prev?? a legisla????o brasileira, a fim de evidenciar a efic??cia das atividades de uma entidade de assist??ncia social. Os resultados obtidos indicam que a vis??o econ??mica, financeira e gerencial destas entidades tornar-se-iam mais claras e interessantes como resultado social aos investidores e detentores de recursos destinados ?? assist??ncia, o que levaria a uma revis??o mais acurada do controle e evidencia????o destes fatores com a cria????o de t??cnicas de avalia????o espec??fica para este setor.

Made available in DSpace on 2015-12-04T11:45:23Z (GMT). No. of bitstreams: 1 Fabio_Monterazo_Silva.pdf: 3083442 bytes, checksum: 5eb6989f45a1f782d1dce2a9f17ce457 (MD5) Previous issue date: 2005-04-25 / The present work deals with the model of Value Based Management (VBM), by means of a bibliographical research, objectifying the specific theoretical revision on the subject and of the main related factors the VBM, and complemented for a study of case in a multinational company, of the branch of foodservices, that use diverse concepts of the VBM in its Model of Management. The main objective of this dissertation was to make a comparative analysis enters current practical of management of the company the object of the case study, with the deriving concepts of the VBM. The work counted on an internal research (Questionnaire), collects of data by means of opened interviews, of little duration, aiming at to get the maximum of information of the company, document collection and direct comment. Having as main conclusions of the work, the evidence that current the practical ones of management of the company are lined up to the concepts of the VBM, according to perception of the managers and by means of a critical analysis of current the practical ones of management of the company. / O presente trabalho trata do modelo de Gest??o Baseada em Valor (GBV), por meio de uma pesquisa bibliogr??fica, objetivando a revis??o te??rica espec??fica sobre o tema e sobre os principais fatores relacionados ?? GBV, complementado por um estudo de caso em uma empresa multinacional do ramo de servi??os de alimenta????o, que utiliza diversos conceitos da GBV no seu Modelo de Gest??o. O objetivo principal desta disserta????o foi fazer uma an??lise comparativa entre as atuais pr??ticas de gest??o da empresa objeto do estudo de caso, com os conceitos oriundos da GBV. O trabalho contou com uma pesquisa interna (question??rio); coleta de dados por meio de entrevistas abertas, de pouca dura????o, visando obter o m??ximo de informa????o da empresa; coleta de documentos e observa????o direta, tendo, como principais conclus??es do trabalho, a constata????o de que as atuais pr??ticas de gest??o da empresa est??o alinhadas aos conceitos da GBV, segundo a percep????o dos gestores e por meio de uma an??lise cr??tica das atuais pr??ticas de gest??o da empresa.

Esta dissertação de mestrado aborda a Composição de Web services baseada em atributos de Qualidade de Serviço (CWSbQ). Foi selecionado o domínio de sistemas de e-commerce, por se tratar de uma área em franca expansão, tanto no cenário nacional como internacional. Além disso, os sistemas de e-commerce podem se beneficiar da CWSbQ devido à sua interoperabilidade e atendimento aos requisitos de qualidade de serviço de seus clientes. Foram implementados dez algoritmos para resolver esse problema, usando várias técnicas diferentes, sendo elas: busca aleatória, busca exaustiva, busca heurística, busca meta-heurística e um algoritmo híbrido. Foram realizados experimentos de avaliação de desempenho, considerando tamanhos de espaço de busca diferentes e dois deadlines estabelecidos. As principais contribuições deste trabalho foram o desenvolvimento de três novos algoritmos: Heurística Gulosa (HG), Heurística Gulosa 2 (HG2) e Algoritmo Genético Duplamente Híbrido (AGDH); o uso de planejamento de experimentos e avaliação de desempenho para aperfeiçoar Algoritmos Genéticos (AGs) usados no problema de CWSbQ; e o estudo de adequação dos algoritmos de CWSbQ para diferentes situações / This MSc dissertation addresses the QoS-aware Web services composition (QWSC) problem. The field of e-commerce systems was selected because it comprises an area in wide expansion, both in national and international scenarios. Furthermore, e-commerce systems can benefit from QWSC due to its interoperability and compliance to the requirements of quality of service of the customers. Ten algorithms were implemented to solve this problem by using several different techniques, namely: random search, exhaustive search, heuristic search, meta-heuristic and a hybrid algorithm. Performance evaluation was made considering different search space sizes for two different established deadlines. The main contributions of this work were the development of three new algorithms: Greedy Heuristic (GH), Greedy Heuristic 2 (GH2) and Doubly Hybrid Genetic Algorithm (DHGA); the use of planning of experiments and performance evaluation to improve the genetic algorithms (GAs) used in QWSC problem; and a suitability study of QWSC algorithms for different situations

Esta tese de Doutorado tem como objetivo apresentar uma arquitetura para metaescalonamento verde com provisão de qualidade de serviço em uma nuvem privada denominada GreenMACC. Essa nova arquitetura oferece a automatização na escolha de políticas em quatro estágios de escalonamento de uma nuvem privada, permitindo cumprir a negociação que foi estabelecida com o usuário. Devido a essa função, é possível garantir que o GreenMACC se comporte seguindo os princípios da computação verde sem deixar de se preocupar com a qualidade do serviço. Nesta tese o GreenMACC é apresentado, detalhado, discutido, validado e avaliado. Com os resultados apresentados pode-se concluir que a arquitetura proposta mostrou-se consistente, permitindo a execução dos serviços requisitados com diversas políticas de escalonamento em todos os seus estágios. Além disso, demonstrou flexibilidade em receber novas políticas, com focos verde e de qualidade de serviço, e eficiência na escolha das políticas de escalonamento de acordo com a negociação feita com o usuário. / This PhD thesis aims to present an architecture for green metascheduling with provision of quality of service in a private cloud called GreenMACC. This new architecture offers the possibility of choosing automatically the four stage scheduling policies of a private cloud, allowing to reach the users negotiation. As a result of this function, it is possible to ensure that GreenMACCs behavior follows the green computing principles and also is worried about the quality of the service. In this thesis Green- MACC is presented, particularized, discussed, validated and evaluated. The results show that the proposed architecture is consistent, allowing the execution of the requested services considering various scheduling policies in the stages. Moreover, GreenMACC proves to be flexible as allows new policies, focusing on green and quality of service, and to be efficient as chooses the scheduling policies following the users negotiation.

A intensificação da globalização tem afetado diretamente organizações e pessoas, não é diferente quando se trata das instituições de ensino superior. Desta forma, a internacionalização do ensino superior vem se intensificando e os impulsionadores destes esforços vêm se tornado cada vez mais fortes nos últimos anos. Diante das demandas que surgem neste contexto de intensa globalização, esforços realizados em resposta a este fenômeno são empreendidos, mas muitas vezes sem o alcance dos resultados esperados. O propósito deste estudo é adaptar e propor o Balanced Scorecard (BSC) como ferramenta de auxílio ao processo de gestão da internacionalização do ensino superior às universidades públicas brasileiras. O estudo se justifica pela compreensão de que organizações precisam monitorar seus processos e resultados. Devem se esforçar para conhecer seus pontos fracos e fortes, bem como as possibilidades de correção de desvios e maximização de resultados, assim contribuindo para o alcance de seus objetivos, entende-se que uma ferramenta voltada ao auxílio das atividades relacionadas a internacionalização do ensino superior pode contribuir diretamente para a melhoria do processo. A metodologia adotada para a condução do estudo foi o estudo de caso, desenvolvido em cinco instituições públicas de ensino superior brasileiras de melhor reputação internacional, em acordo com cinco rankings internacionais. A análise dos resultados proporcionou a identificação de seis perspectivas a serem utilizadas no BSC proposto: 1. Perspectiva da mudança organizacional; 2. Perspectiva dos recursos materiais, financeiros e estruturais; 3. Perspectiva do desenvolvimento de pessoas; 4. Perspectiva da inovação curricular; 5. Perspectiva da mobilidade acadêmica e 6. Perspectiva dos stakeholders. A partir da definição destas perspectivas, apresentou-se o mapa estratégico a ser utilizado pelas universidades. / The intensification of globalization has directly affected organizations and individuals, is no different when it comes to higher education institutions. Thus, the Internationalization of higher education has been increasing and the drivers of these efforts has become increasingly stronger in recent years. Faced with the demands that arise in this context of intense globalization, efforts made in response to this phenomenon are undertaken, but often without achieving the expected results. The purpose of this study is to adapt and propose the Balanced Scorecard (BSC) as a tool for the management process of higher education internationalization to the Brazilian public universities. The study is justified by the understanding that any organization needs to monitor their processes and results, should strive to know their strengths and weaknesses, as well as the correction of possible deviations and maximization of results, thus contributing to the achievement of its objectives, it is understood that a tool aimed to support activities related to internationalization of higher education can contribute directly to the improvement of the process. The methodology used to conduct the study was the case study, developed in five best international reputation public higher education institutions in Brazil, in accordance with five international rankings. The analysis provided the identification of six perspectives to be used in the proposed BSC: 1. Organizational change perspective; 2. Material, financial and structural resources perspective; 3. People development perspective; 4. Curriculum innovation perspective; 5. Academic mobility perspective and 6. Stakeholders perspective. From the definition of these perspectives, presented the strategic map to be used by universities.

O modelo de gestão pública adotado pelo estado de Minas Gerais, conhecido como \"Choque de Gestão\", foi implementado utilizando-se de um instrumento de pactuação de resultados, denominado \"Acordo de Resultados\", que prevê possíveis recompensas para o alcance das metas pactuadas. Considerando o Acordo de Resultados e a premissa de que os agentes fazem ajustes ou mudanças nos indicadores de desempenho nele contidos para adequar interesses distintos àqueles inicialmente almejados, esta pesquisa buscou identificar os fatores organizacionais e ambientais que influenciam as alterações dos indicadores de desempenho na estrutura gerencial do governo mineiro, à luz da Teoria de Agência e da Teoria da Contingência. Para alcançar o objetivo proposto, realizou-se um estudo de caso contendo abordagens quantitativa e qualitativa, utilizando-se de análise documental, questionário e entrevistas semiestruturadas para a coleta de dados. Em um primeiro momento, realizou-se a análise quantitativa dos dados, por meio de análise fatorial e regressão logística, para verificar os fatores associados as alterações dos indicadores de desempenho identificados nos documentos de celebração do Acordo de Resultados em um período de quatro anos. Posteriormente, foram analisadas as entrevistas realizadas, por meio de análise de conteúdo, para captar possíveis elementos não observados na análise quantitativa. Os resultados encontrados evidenciam que a maneira como os indicadores de desempenho foram aplicados, sem integração, pensando em cada secretaria individualmente e contando com um órgão que acompanha a gestão de maneira frágil, faz com que o Acordo de Resultados se mostre volátil e não proporcione o benefício esperado como instrumento de controle nem como promotor de melhorias no processo de gestão. Encontrou-se ainda que, a accountability é comprometida pela fragilidade da estrutura gerencial por meio das alterações dos indicadores, sendo que a mesma poderia também atuar como como parte de um conjunto de possíveis soluções para mitigar os problemas detectados ao longo da análises realizadas, agindo como um mecanismo de proteção contra alterações indevidas nos indicadores de desempenho. Assim, concluiu-se que as ferramentas gerenciais aportadas no Choque de Gestão apresentam-se insuficientes para blindar a estrutura gerencial do modelo de gestão diante de algumas pressões identificadas com base nas Teorias da Agência e na Teoria da Contingência, desvirtuando o modelo inicialmente proposto e promovendo alterações nos indicadores. / The government of the Brazilian state of Minas Gerais adopted a management model, known as \"Management Shock\" (Choque de Gestão), by way of covenants called \"Agreement on Results\", which foresee possible rewarding for the achievement of targets agreed upon. Considering such covenants and the assumption that agents can promote adjustments or changes in performance indicators therein contained, in order to suit interests different of those initially targeted, this research sought to identify, in light of the Agency and Contingency Theories, the organizational and environmental factors influencing performance indicators changes in the government\'s management structure. To this end, we conducted a case study, comprising quantitative and qualitative approaches, using documentary analysis, a questionnaire and semi-structured interviews to collect data. We initially performed a quantitative data analysis, through factor analysis and logistic regression, to ascertain the factors associated with changes in performance indicators identified in covenants celebrated over a period of four years. The interviews were subsequently submitted to content analysis, in order to capture elements that possibly passed unnoticed in the quantitative analysis. Results point out that lack of integration in the application of performance indicators, by regarding each department by itself and relying on a governmental agency that only feebly supervises management, leads to covenants proving volatile and not providing its expected benefits as control tools or acting as enhancers to the management process. We also found that accountability is compromised by the management\'s structure weakness, incurred through changes to indicators. It is pointed out that accountability could be part of a set of possible solutions directed to mitigate the problems identified throughout the analysis, acting as a protection mechanism against unauthorized changes in performance indicators. We conclude that the tools provided under \"Management Shock\" are not sufficient to shield the model\'s managerial structure from pressures identified according to the Agency and Contingency Theories, undermining the model, as originally proposed, and allowing for indicators changes.

Our goal in this research is to investigate and determine how to best support a challenging mobile wireless network based in a military operational environment. Since routing protocols used in mobile ad hoc networks (MANET) must adapt to frequent or continual changes of topology, while simultaneously limiting the impact of tracking these changes on wireless resources, we focused our initial research on improving the efficiency of route discovery. We proposed and designed a new MAC layer routing protocol that pursues reduced routing overhead, greater interaction of network protocol layers and passive neighbor/path discovery. This algorithm, called Virtual MAC Tag Switching (VMTS), evolved as we implemented a prototype in the ns-2 network simulator and conducted simulation analysis of existing protocols: DSDV, DSR and AODV. Upon analyzing the performance of existing routing protocols using pragmatic metrics not applied in any MANET literature it was found that current MANET models produce unsatisfactory performance. Subsequent analysis of transport layer protocol behaviors pinpointed the causes that undermine the performance of the existing protocols and would have thwarted VMTS as well.