M.Com. / The auditor has the objective to express an opinion on the financial statements on which he is reporting. It is important for the auditor to know that the data which he is auditing has not been changed without the necessary authority or been lost and that the data meets the three Information Security Objectives (IS0s) ...

<div><p>Modern mobile devices have numerous ephemeral tasks. These tasks are driven by background activities, such as push notifications and sensor readings. In order to execute these tasks, the whole platform has to periodically wake up beforehand, and go to sleep afterwards. During this process, the OS kernel operates on power state of various IO devices, which has been identified as the bottleneck for energy efficiency. To this end, we want to offload this kernel phase to a more energy efficient, microcontroller level core, named peripheral core.</p></div><div><p> </p></div><div><p>To execute commodity OS on a peripheral core, existing approaches either require much engineering effort or incur high execution cost. Therefore, we proposed a new OS model called transkernel. By utilizing cross-ISA dynamic binary translation (DBT) technique, transkernel creates a virtualized environment on the peripheral core. It relies on a small set of stable interfaces. It is specialized for frequently executed kernel path. It exploits ISA similarities to reduce DBT overhead.</p></div><div><p> </p></div><div><p>We implement a transkernel model on ARM platform. With novel design and optimization, we demonstrate that a transkernel can gain energy efficiency. Moreover, it provides a new OS design to harness heterogeneous SoCs.</p></div>

As Máquinas Virtuais ganharam grande importância com o advento de processadores multi-core (na plataforma x86) e com o barateamento de componentes de hardware, como a memória. Por conta desse substancial aumento do poder computacional, surgiu o desafio de tirar proveito dos recursos ociosos encontrados nos ambientes corporativos, cada vez mais populados por equipamentos multi-core e com vários Gigabytes de memória. A virtualização, mesmo sendo um conceito já antigo, tornou-se novamente popular neste cenário, pois com ela foi possível utilizar melhor os recursos computacionais, agora abundantes. Este trabalho tem como principal foco estudar algumas das principais técnicas de gerência de recursos computacionais em ambientes virtualizados. Apesar de muitos dos conceitos aplicados nos projetos de Monitores de Máquinas Virtuais terem sido portados de Sistemas Operacionais convencionais com pouca, ou nenhuma, alteração; alguns dos recursos ainda são difíceis de virtualizar com eficiência devido a paradigmas herdados desses mesmos Sistemas Operacionais. Por fim, é apresentado o Memory Dispatcher (MD), um mecanismo de gerenciamento de memória, com o objetivo principal de distribuir a memória entre as Máquinas Virtuais de modo mais eficaz. Este mecanismo, implementado em C, foi testado no Monitor de Máquinas Virtuais Xen e apresentou ganhos de memória de até 70%. / Virtual Machines have gained great importance with advent of multi-core processors (on platform x86) and with low cost of hardware parts, like physical memory. Due to this computational power improvement a new challenge to take advantage of idle resources has been created. The virtualization technology, even being an old concept became popular in research centers and corporations. With this technology idle resources now can be exploited. This work has the objective to show the main techniques to manage computational resources in virtual environments. Although many of current concepts used in Virtual Machine Monitors project has been ported, with minimal changes, from conventional Operating Systems there are some resources that are difficult to virtualize with efficiency due to old paradigms still present in Operating Systems projects. Finally, the Memory Dispatcher (MD) is presented, a mechanism used to memory management. The main objective of MD is to improve the memory share among Virtual Machines. This mechanism was developed in C and it was tested in Xen Virtual Machine Monitor. The MD showed memory gains up to 70%.

In this paper I describe a motion planning technique for intelligent ground vehicles. The technique is an implementation of a path selection algorithm based on fuzzy inference. The approach extends on the motion planning algorithm known as driving with tentacles. The selection of the tentacle (a drivable path) to follow relies on the calculation of a weighted cost function for each tentacle in the current speed set, and depends on variables such as the distance to the desired position, speed, and the closeness of a tentacle to any obstacles. A Matlab simulation and the practical implementation of the fuzzy inference rule on a Clearpath Husky robot within the Robot Operating System (ROS) framework are provided.

Based on analysis of human-human interactions, we have developed an initial model of engagement for human-robot interaction which includes the concept of connection events, consisting of: directed gaze, mutual facial gaze, conversational adjacency pairs, and backchannels. We implemented the model in the open source Robot Operating System and conducted a human-robot interaction experiment to evaluate it.

Made available in DSpace on 2015-03-05T17:05:26Z (GMT). No. of bitstreams: 0 Previous issue date: 20 / Nenhuma / Essa dissertação investiga o Sistema Operacional da United Technologies Corporation - UTC, denominado ACE, identificando e analisando as suas inter-relações com o Sistema de Gestão da Qualidade ISO9001. A metodologia de pesquisa se caracteriza pela abordagem qualitativa e estudo de caso único incorporado, o qual é realizado em três etapas. A primeira etapa é uma descrição ampla do Sistema Operacional ACE no sentido de apresentar esse sistema à academia. A segunda etapa é o estudo das inter-relações entre os dois sistemas teóricos. Na terceira etapa são estudadas as inter-relações entre as práticas prescritas dos dois sistemas em uma das unidades de manufatura da UTC. A identificação e análise das inter-relações realizadas neste estudo apresentam uma estrutura organizada que permite o planejamento de um projeto de unificação dos sistemas. Outra contribuição relevante deste estudo é a possibilidade de utilização do método para analisar inter-relações entre outros sistemas. / This research investigates the Operating System of the United Technologies Corporation - UTC, called ACE, identifying and analyzing their interrelations with the Quality Management System ISO9001. The methodology of this research is characterized by a qualitative approach and case study incorporated, which is conducted in three stages. The first step is a broad description of the ACE Operating System to introduce this system to the academy. The second step is the study of the interrelationship between the two theoretical systems. In the third stage are studied the relationship between the practices prescribed for the two systems in one UTC manufacturing unit. The identification and analysis of the interrelations in this study have made an organized structure that allows the planning of a project of unification of the systems. Another important contribution of this study is the use of the method for analyzing the interrelations between others systems.

nÃo hà / Em projetos de desenvolvimento de sistemas embarcados normalmente adota-se uma abordagem de âtentativa e erroâ nas atividades relacionadas ao porte do sistema operacional(SO), resultando em um porte incompleto ou inconsistente. Nesta pesquisa apresenta-se um trabalho original onde se propÃe uma soluÃÃo para esta abordagem atravÃs de uma metodologia completa para a detecÃÃo das partes do SO que devem ser ajustadas de forma que o SO seja portado para a nova plataforma de hardware. A metodologia proposta combina as informaÃÃes do cÃdigo-fonte do SO e as particularidades do novo hardware, resultando em: uma lista completa do cÃdigo-fonte que deve ser ajustado; a interdependÃncia entre estes cÃdigos-fonte; a ordem de prioridade de modificaÃÃo para cada cÃdigo-fonte; e um cronograma baseado em esforÃo, para auxiliar o planejamento das modificaÃÃes. Adicionalmente, propÃe-se um algoritmo para a resoluÃÃo de referÃncias cÃclicas em arquivos de cÃdigo-fonte. Por fim, à apresentado um estudo de caso baseado em uma aplicaÃÃo desenvolvida segundo a metodologia proposta. / Embedded system development frequently uses the âtrial and errorâ approach for Operating System (OS) porting,resulting in incomplete or inconsistent porting. In this work, we present a pioneer work addressing this issue. We propose a complete method for detecting OS parts that should be adjusted in order to port the OS into a new hardware platform. The proposed method combines information from the OS source-code and peculiarities of the new hardware platform, resulting in: a complete list of source-codes that must be adjusted; the interdependence between these source-codes; the priority order of modifications for each source-code; and an effort-based schedule to help planning the modifications. In addition, we propose an algorithm dealing with source-codeâs cyclic references. Finally, we present a study-case based on an application developed according the proposed method

As Máquinas Virtuais ganharam grande importância com o advento de processadores multi-core (na plataforma x86) e com o barateamento de componentes de hardware, como a memória. Por conta desse substancial aumento do poder computacional, surgiu o desafio de tirar proveito dos recursos ociosos encontrados nos ambientes corporativos, cada vez mais populados por equipamentos multi-core e com vários Gigabytes de memória. A virtualização, mesmo sendo um conceito já antigo, tornou-se novamente popular neste cenário, pois com ela foi possível utilizar melhor os recursos computacionais, agora abundantes. Este trabalho tem como principal foco estudar algumas das principais técnicas de gerência de recursos computacionais em ambientes virtualizados. Apesar de muitos dos conceitos aplicados nos projetos de Monitores de Máquinas Virtuais terem sido portados de Sistemas Operacionais convencionais com pouca, ou nenhuma, alteração; alguns dos recursos ainda são difíceis de virtualizar com eficiência devido a paradigmas herdados desses mesmos Sistemas Operacionais. Por fim, é apresentado o Memory Dispatcher (MD), um mecanismo de gerenciamento de memória, com o objetivo principal de distribuir a memória entre as Máquinas Virtuais de modo mais eficaz. Este mecanismo, implementado em C, foi testado no Monitor de Máquinas Virtuais Xen e apresentou ganhos de memória de até 70%. / Virtual Machines have gained great importance with advent of multi-core processors (on platform x86) and with low cost of hardware parts, like physical memory. Due to this computational power improvement a new challenge to take advantage of idle resources has been created. The virtualization technology, even being an old concept became popular in research centers and corporations. With this technology idle resources now can be exploited. This work has the objective to show the main techniques to manage computational resources in virtual environments. Although many of current concepts used in Virtual Machine Monitors project has been ported, with minimal changes, from conventional Operating Systems there are some resources that are difficult to virtualize with efficiency due to old paradigms still present in Operating Systems projects. Finally, the Memory Dispatcher (MD) is presented, a mechanism used to memory management. The main objective of MD is to improve the memory share among Virtual Machines. This mechanism was developed in C and it was tested in Xen Virtual Machine Monitor. The MD showed memory gains up to 70%.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-07-25T17:21:34Z No. of bitstreams: 1 RaphaelSantos.pdf: 3718930 bytes, checksum: df335fd5562e8156000972c282fe9724 (MD5) / Made available in DSpace on 2017-07-25T17:21:34Z (GMT). No. of bitstreams: 1 RaphaelSantos.pdf: 3718930 bytes, checksum: df335fd5562e8156000972c282fe9724 (MD5) Previous issue date: 2016-08-17 / Autonomous exploration, in robotics, can be defined as the act of moving into an unknown environment, at priori, while building up a map of the environment. A great deal of literature describes several problems that are relate to the strategy exploration: perception, location, trajectory control and mapping. This work aims to present an autonomous exploration algorithm based on metaheuristics. Therefore, the problem of autonomous exploration of mobile robots is formulated as an optimization problem, providing data for metaheuristics that are able to search points in the space of solutions that represent positions on the map under construction that best meet the objectives of the exploration. Metaheuristics are approximate methods that guarantee sufficiently good solutions to optimization problems. The proposal was implemented and incorporated as an optimization module in a simultaneous location and mapping system that was run on the Robot Operating System environment and proved to be able to guide a simulated robot without human intervention. Two optimization metaheuristics were implemented to guide target to simulated robot: Genetic Algorithm and Firefly Algorithm. Both algorithms have achieved good results, however the second one was able to guide robot by best trajectories. / Exploração autônoma, em robótica, pode ser definida como o ato de mover-se em um ambiente, a princípio desconhecido, enquanto constrói-se um mapa deste ambiente. Uma grande parte da literatura relata vários problemas que se relacionam com a estratégia de exploração: percepção, localização, trajetória, controle e mapeamento. Este trabalho visa apresentar um algoritmo de exploração autonoma baseado em metaheurísticas. Para tanto, o problema de exploração autônoma de robôs móveis é formulado como um problema de otimização, fornecendo dados para que metaheurísticas sejam capazes de buscar pontos no espaço de soluções que representam posições no mapa em construção que melhor satisfaçam os objetivos da exploração. Metaheuristicas são metodos aproximados que garantem soluções suficientemente boas para problemas de otimização. A proposta foi implementada e incorporada como um módulo de otimização em um sistema de localização e mapeamento simultâneos que foi executado em ambiente Robot Operating System e mostrou-se capaz de guiar um robô simulado sem intervenção humana. As metaheurísticas usadas foram o Algoritmo Genético e o Algoritmo de Vagalumes. Ambos os algoritmos obtiveram bons resultados, no entanto o Algoritmo de Vagalumes guiou o robô por trajetórias melhores.

<p>This thesis presents an evaluation of the Solaris version of the Xen virtual machine monitor and a comparison of its performance to the performance of Solaris Containers under similar conditions. Xen is a virtual machine monitor, based on the paravirtualization approach, which provides an instruction set different to the native machine environment and therefore requires modifications to the guest operating systems. Solaris Zones is an operating system-level virtualization technology that is part of the Solaris OS. Furthermore, we provide a basic performance evaluation of the security modules for Xen and Zones, known as sHype and Solaris Trusted Extensions, respectively.</p><p>We evaluate the control domain (know as Domain-0) and the user domain performance as the number of user domains increases. Testing Domain-0 with an increasing number of user domains allows us to evaluate how much overhead virtual operating systems impose in the idle state and how their number influences the overall system performance. Testing one user domain and increasing the number of idle domains allows us to evaluate how the number of domains influences operating system performance. Testing concurrently loaded increasing numbers of user domains we investigate total system efficiency and load balancing dependent on the number of running systems.</p><p>System performance was limited by CPU, memory, and hard drive characteristics. In the case of CPU-bound tests Xen exhibited performance close to the performance of Zones and to the native Solaris performance, loosing 2-3% due to the virtualization overhead. In case of memory-bound and hard drive-bound tests Xen showed 5 to 10 times worse performance.</p>