Tem como objetivo estudar e otimizar o desempenho de frenagem do ônibus biarticulado que trafega nas grandes cidades brasileiras. Apresenta-se um estudo do sistema de freios do veículo e propõe-se um modelo matemático para o cálculo de todas as forças que agem no sistema de freio e nas rodas. O programa computacional calcula as forças de frenagem que atuam nos eixos, as forças verticais nos eixos, as forças de inércia, o coeficiente de adesão utilizado por eixo, a desaceleração do veículo, o espaço de parada e a eficiência do sistema de freio. Os resultados são confrontados com a norma internacional ECE-R13 a fim de verificar se o veículo obedece aos requisitos estabelecidos pela mesma. / This work is concerned with the study optimization the breaking system of a biaticulated bus, which circulates in many Brazilian cities. The vehicle brake system is studied and a mathematical model is proposed in order to calculate all forces in the brake systems and in the wheels. Based on a computational program the brake force in the axles, the vertical forces in the axles, the inertia forces, the adhesion coefficient requested by each axles, the vehicle deceleration, the brake distance and the brake system efficiency are calculated. The results are compared with the international standard ECE-R13 to verify whether the bus satisfies the regulation.

Esta dissertação relata resultados obtidos por ações de uma tentativa para mostrar que o uso de conceitos e definições sobre auditoria de qualidade pode contribuir para orientar análises sobre o transporte público urbano por ônibus, um item básico da mobilidade urbana. Também se mostrou que conceitos sugeridos pelas normas NBR ISO séries 9.000 e 10.000 podem contribuir para identificar características das \"viagens por ônibus urbano\" e classificar itens que condicionam o nível para a qualidade do serviço prestado por transporte. Resumem-se as principais conceitos a serem usados, em particular o uso de \"escalas\" obtidas a partir de entrevistas a usuários, tópicos sobre o uso de Normas para controle de auditorias, resultados de um estudo de caso, o transporte por ônibus em Piracicaba, Estado de São Paulo. / That dissertation tells the results obtained in actions of an attempt to show that the use of concepts and definitions on quality auditing can contribute to guide analyses on the urban public bus transportation, a basic item of the urban mobility. It was also shown that concepts suggested by the Brazilian Standards NBR ISO series 9.000 and 10.000 can contribute to identify characteristics of the \"rides on urban bus\" and to classify items that condition the level for the quality of the service rendered by transport. The main concepts are summarized to be used, in matter the use of \"scales\" obtained starting from interviews to users; topics on use of Norms for control of auditing; results of a case study, the transport for bus in Piracicaba, state of São Paulo, Brazil.

Esta dissertação relata resultados obtidos por ações de uma tentativa para mostrar que o uso de conceitos e definições sobre auditoria de qualidade pode contribuir para orientar análises sobre o transporte público urbano por ônibus, um item básico da mobilidade urbana. Também se mostrou que conceitos sugeridos pelas normas NBR ISO séries 9.000 e 10.000 podem contribuir para identificar características das \"viagens por ônibus urbano\" e classificar itens que condicionam o nível para a qualidade do serviço prestado por transporte. Resumem-se as principais conceitos a serem usados, em particular o uso de \"escalas\" obtidas a partir de entrevistas a usuários, tópicos sobre o uso de Normas para controle de auditorias, resultados de um estudo de caso, o transporte por ônibus em Piracicaba, Estado de São Paulo. / That dissertation tells the results obtained in actions of an attempt to show that the use of concepts and definitions on quality auditing can contribute to guide analyses on the urban public bus transportation, a basic item of the urban mobility. It was also shown that concepts suggested by the Brazilian Standards NBR ISO series 9.000 and 10.000 can contribute to identify characteristics of the \"rides on urban bus\" and to classify items that condition the level for the quality of the service rendered by transport. The main concepts are summarized to be used, in matter the use of \"scales\" obtained starting from interviews to users; topics on use of Norms for control of auditing; results of a case study, the transport for bus in Piracicaba, state of São Paulo, Brazil.

This thesis explores hardware command capture as a viable means of analyzing real world hard drive usage. Hardware command capture provides insight into the IO stack where current tools fail to reach. A software platform is presented which provides trace conversion and analysis capabilities. This platform is written in Python and designed to handle traces of arbitrary size while being easily extensible for future projects to build upon. A novel Sequential Stream Detection algorithm built upon the software platform is then presented. This algorithm detects application level sequential streams and provides interesting insight into the sequential nature of the applications analyzed. The software platform and Sequential Stream Detector were validated and run against a range of workloads including video playback, large project compilations, and synthetic benchmarks. Where applicable, each workload was run on multiple file systems (ext2, ext3, ext4, Btrfs) to compare the effects of stream allocation across file systems. It is shown that stream allocation is consistent across file systems suggesting stream detection may be a valuable workload identification tool.

U.S. school bus drivers witness bullying on their buses on a regular basis but are often not consulted on how to prevent bullying or how to maintain a safe environment. Over 24 million U.S. student passengers ride school buses daily, yet the voices of bus drivers have been inadequately represented in the development of school bullying policies. The purpose of this phenomenological study was to examine the lived experience of 12 active school bus drivers and their perceptions of bullying on the bus, driver training programs, school antibullying policies, and other mandated procedures developed for bus drivers. The conceptual framework combined Bandura's social learning theory and Bronfenbrenner's social ecological systems model. Data were sorted into 14 themes from semistructured interviews that were coded and analyzed using Moustakas's methodology of bracketing personal opinion, horizonalization, and privileging rich textural description in participants' language. Findings indicated that these bus drivers do feel supported by school administrators, but they lack continuous training, rely on experience over training, are subject to intimidation and threats by students and parents, and seek greater communication with student support groups. Positive social change implications include recommendations to school district administrators to develop driver antibullying training which takes into account all components of passenger safety. Findings support development of administrative policy mandating a direct, ongoing channel of communication between drivers and school administrators to assure antibullying policy implementation fidelity.

Zugl.: Karlsruhe, Universiẗat, Diss., 2007.

L'architecture massivement parallèle étudiée dans cette thèse tente d'associer un fonctionnement de type mimd a des unités de calcul de petite taille, contrairement a ce qui se fait traditionnellement, afin de rendre possible la réalisation de machines de très grande échelle. Elle se situe dans la continuité des machines de type réseau cellulaire étudiées au sein du groupe circuits du LGI (asynchrones, topologie en grille 2d, communication par passage de message) mais dans une optique non dédiée. Cette vocation généraliste pose le probleme du dimensionnement relatif des éléments (processeur, routeur, mémoire) qui doit concilier économie et fonctionnalité. A la lumière d'une approche expérimentale par simulations, le mécanisme de transfert de message parallèle utilise jusqu'alors apparait comme surdimensionne et trop exigeant d'un point de vue connectique. Des solutions plus réalistes (wormhole multiplexe, bus intra-chip) sont présentées et montrées comme suffisamment puissantes. L'étude d'un certain nombre de programmes d'exemples a permis d'une part d'améliorer de façon significative le jeu d'instructions et de valider un ensemble de primitives de communication simples, d'autre part de montrer que l'implémentation d'algorithmes de natures très variées était possible

Cette thèse a été réalisée dans le cadre d'une collaboration entre l'université d'Angers et la société Perinfo. Elle porte sur le développement de nouveaux modèles et algorithmes dédiés à la détermination des horaires de lignes dans les réseaux de bus. Le coeur de ce manuscrit est la qualité de service perçue par l'usager. Nous réalisons dans un premier temps un état de l'art des étapes relatives à la planification du réseau. Nous proposons ensuite un modèle et des fonctions d'évaluation pour les objectifs de synchronisation des correspondances et de régularité du cadencement. Ces éléments sont utilisés au sein d'une méthode de recherche locale basée sur un ensemble de voisinages que nous définissons pour le problème. Notre troisième contribution est la modélisation d'un problème original et intégré qui résout simultanément le problème de fixation des horaires et de création des affectations de véhicules. Pour ce problème complexe, nous proposons une méthode de résolution hybride basée sur une recherche locale itérée et un algorithme exact par enchères, ainsi que deux voisinages spécifiques. Les tests réalisés sur données réelles valident la supériorité de l'approche simultanée par comparaison avec la situation existante et l'approche séquentielle, tant au niveau de la qualité de service que des coûts économiques. Enfin, nous étudions une problématique originale qui prend à contre-courant le processus traditionnel de planification. Ce problème de fixation des horaires, visant des objectifs liés aux correspondances, prend pour contraintes les séquences de courses affectées aux véhicules et aux conducteurs. Cette approche permet d'améliorer la qualité de service sans remettre en cause les plannings d'exploitation. Une méthode tabou basée sur deux voisinages adaptés est développée et testée sur un cas d'étude.

Thesis (M. A.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

In the System-on-Chip (SoC) era, common industry estimates are that functional verification takes approximately 70% of the total effort on a project. For the time-to-market constrain, it¡¦s a challenge to reduce the SoC verification/debugging time efficiently. In an SoC, a microprocessor is an essential part of it. First, we focus the debugging problem on microprocessors. An in-circuit emulation (ICE) module that can be embedded with a microprocessor core. The ICE module, based on the IEEE 1149.1 JTAG architecture, supports typical debugging and testing mechanisms, including boundary scan paths, partial scan paths, single stepping, internal resource monitoring and modification, breakpoint detection, and mode switching between debugging and normal modes. The architecture of the ICE module is parameterized and retargetable to different microprocessors. It has been successfully integrated with two microprocessors with significantly different architectures: one 8-bit industrial embedded microcontroller HT48x00 and one 32-bit ARM7-like embedded microprocessor. FPGA prototypes and chip implementation have been accomplished. Experiments show that real-time (on-line) debugging at full speed is possible with the embedded ICE at a minor gate count overhead. Collecting the program execution traces at full speed is essential to the analysis and debugging of real-time software behavior of a complex system. However, the generation rate and the size of real time program traces are so huge such that real-time program tracing is often infeasible without proper hardware support. This paper presents a hardware approach to compress program execution traces in real time in order to reduce the trace size. The approach consists of three modularized phases: (1) branch/target filtering, (2) branch/target address encoding and (3) Lempel-Ziv-based data compression. A synthesizable RTL code for the proposed hardware is constructed to analyze the hardware cost and speed and typical multimedia benchmarks are used to measure the compression results. The results show that our hardware is capable of real time compression and achieving compression ratio of 454:1, far better than 5:1 achieved by typical existing hardware approaches. Furthermore, our modularized approach makes it possible to trade off between the hardware cost (typically from 1K to 50K gates) and the achievable compression ratio (typically from 5:1 to 454:1). For SoC debugging, bus signal tracing represents that the information which is generated from the system can be collected for later observation, debugging and analysis. However, the generation rate and the size of real time system traces are so huge such that a mechanism for system tracing that can reduce trace size efficiently is needed. In this paper, we propose a multi-resolution bus trace approach. The hardware bus tracer consists of two major stages: (1) signal monitor & tracing stage, and (2) trace compression stage. In the first stage, designer can trace the signals in detail or in rough depends on the debug purpose. In other word, the multi-resolution trace approach provides the trade-off between trace accuracy and trace depth. In the second stage, the bus tracer compresses the trace size efficiently; therefore the capability of on-chip storage is increased. In the host, the analyzer tool decompresses the trace data for future observation and debugging.