Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2007. / Submitted by Luis Felipe Souza (luis_felas@globo.com) on 2009-01-09T13:17:21Z No. of bitstreams: 1 Dissertacao_2007_JorgeSchtoltz.pdf: 2102171 bytes, checksum: a4bba0ce43d48ec2f9d4854022bc8eb4 (MD5) / Approved for entry into archive by Georgia Fernandes(georgia@bce.unb.br) on 2009-03-04T14:38:24Z (GMT) No. of bitstreams: 1 Dissertacao_2007_JorgeSchtoltz.pdf: 2102171 bytes, checksum: a4bba0ce43d48ec2f9d4854022bc8eb4 (MD5) / Made available in DSpace on 2009-03-04T14:38:24Z (GMT). No. of bitstreams: 1 Dissertacao_2007_JorgeSchtoltz.pdf: 2102171 bytes, checksum: a4bba0ce43d48ec2f9d4854022bc8eb4 (MD5) / O escalonamento estático de um programa, representado por um grafo dirigido acíclico de tarefas, em um ambiente multiprocessado, tem o objetivo de minimizar o tempo de conclusão do programa. Apesar das pesquisas nesta área terem obtido heurísticas eficientes, encontrar um escalonamento ótimo é um problema NP - Completo. Clusters de workstations podem ser utilizados no processamento paralelo de programas e devido à complexidade de integração entre os programas, o monitoramento e a simulação são efetuados através de ferramentas que gerenciam o cluster e a execução dos programas paralelos. Dentre as ferramentas analisadas, o PM2P, será utilizado como base de estudo devido ao conhecimento da ferramenta. O objetivo deste trabalho é o desenvolvimento e implementação na ferramenta citada um monitoramento periódico para verificar a disponibilidade das máquinas do cluster e re-escalonar os programas se houver necessidade ou ganho de desempenho. Para testar este monitoramento foram implementados, devido à carência de algoritmos na ferramenta, três algoritmos estáticos voltados para o escalonamento de tarefas que possam ser representados por um GDA (Grafo Dirigido Acíclico). Estes algoritmos funcionam de forma similar, gerando uma lista em ordem topológica das tarefas e àquelas pertencentes ao mesmo nível, portanto, concorrentes entre si, são ordenadas pelo maior ou menor tempo de execução. As tarefas são distribuídas de acordo com a disponibilidade das máquinas no cluster e o objetivo do algoritmo de escalonamento é manter o makespan gerado igual ao tempo do caminho crítico do grafo. Os resultados dos testes, as conclusões sobre o monitoramento e re-escalonamento serão demonstradas através de tabelas e mapas de Gantt para facilitar a visualização e o entendimento. Foram testados conjuntos de tarefas distintas que representam aplicações exemplo. Foi observado que aplicações rápidas, que finalizam sua execução concomitante ou logo após o tempo gasto para verificar a disponibilidade das máquinas no cluster, o monitoramento e o reescalonamento não são necessários e neste caso é recomendável o reinício da aplicação. Ao contrário, aplicações que demandam mais tempo para sua execução, o monitoramento e o re-início de algum programa no caso de indisponibilidade de uma máquina são importantes, uma vez que a aplicação continua sua execução com a nova arquitetura de máquinas, a partir do ponto de detecção da falha. Apesar do custo adicional para execução da atividade, conclui-se que há vantagens em se ter um cluster monitorado quando da execução dos programas paralelos utilizando a biblioteca MPI. ______________________________________________________________________________________________________ ABSTRACT / Static scheduling of a program represented by a directed acyclic graph task on a multiprocessor environment to minimize the program completion time is the goal. It is a wellknown problem of concurrent processing. Although the researches in this area already have reached heuristic efficient to find an optimal scheduling is a NP-Complete problem. The Cluster of Workstations can be used to the parallel processing of programs and due to the program interaction complexity, the monitoring and the simulation are made through frameworks that manage the cluster and the parallel program execution. Among the frameworks analyzed, the framework PM2P, will be used as the base study. The objective of this work is the development and implements a periodic monitoring to verify the machines availability at the cluster and rescheduling the programs whether is necessary or to improve the performance. It has been implemented, to test this periodic monitoring due to the framework algorithms lack new three static algorithms toward the scheduling of programs of tasks that could be represented by DAG (Directed Acyclic Graph). These three algorithms working in a similar way, each one create a topological order list of the tasks and they scheduling the tasks that belongs at the same level of the graph and ordering these tasks by the bigger or smaller execution time criteria. The tasks are sorted and distributed through the cluster machines in accordance with the availability of them. The scheduling goal is getting the graph makespan like the critical path time. The tests results, monitoring conclusions and the scheduling algorithms proposals will be demonstrated with tables and Gantt charts to a best exhibition and comprehension. The tests were over sets of different tasks that representing some real application. It was observed that applications with small execution time finish their at the same time or as soon as the framework check the cluster machines availability. In these cases are not necessary to rescheduling the applications and is recommended restart them. By the other hand, applications with big execution time, the programs monitoring and the restart of some program is important if any machine become unavailability. So, the application continues this execution at the restart point using the other workstations. Nevertheless the additional monitoring overhead, the conclusions show that exist advantages of monitoring the cluster when are executing a parallel programs using the MPI library with a big execution time.

Made available in DSpace on 2015-07-22T20:50:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-29 / OBJETIVOS: Este estudo clínico randomizado mascarado foi realizado para verificar os efeitos de um protocolo de exercícios funcionais sob a forma de “workstations”, comparado a um programa educativo para prevenção de quedas e a um programa educativo com demonstração de exercícios funcionais sobre o desempenho do equilíbrio, mobilidade e ocorrência de quedas em idosos com história de quedas. MÉTODOS: 165 idosos com história de quedas e TUGT entre 13,5 e 30 segundos foram avaliados e randomizados em 3 grupos: (1) orientações; (2) orientações e demonstração de exercícios funcionais; e (3) workstations. O atendimento era semanal e os grupos foram reavaliados por um observador cego após 3 meses, com as medidas de resultado incluindo a melhora do teste TUGT (variável-resposta do estudo) e de outros testes de equilíbrio e mobilidade e nível funcional (TUGT Manual, TUGT Cognitivo, OARS, escala de equilíbrio de Berg, alcance Funcional, CTSIB, estratégias reativas de equilíbrio e DGI-8) e quedas. RESULTADOS: Houve melhora nos escores de todos os testes para os 3 grupos, sendo que diferenças estatisticamente significativas só foram encontradas entre os grupos quanto ao teste TUGT (p=0,035), ocorrendo maior redução no tempo de realização deste teste no grupo de “workstations”. CONCLUSÃO: Nossos achados sugerem que a participação em um programa semanal de exercícios baseado em “workstations” é mais efetiva que os outros dois grupos em melhorar o equilíbrio e mobilidade em idosos, mas pesquisas futuras são necessárias para se traçar estratégias adicionais que possam sustentar e maximizar estes benefícios. / OBJECTIVES: A randomized and blinded clinical trial was carried out on elderly individuals with a history of falls to determine the effect of a “workstation” exercise protocol on balance, mobility and the occurrence of falls compared to an educational program for the prevention of falls and an educational program with a demonstration of functional exercises. METHODS: One hundred sixty-five elderly individuals with a history of falls and TUGT times between 13.5 and 30 seconds were evaluated and randomly divided into three groups: (1) orientation; (2) orientation and demonstration of functional exercises; and (3) workstations. Weekly sessions were given and the groups were reevaluated by a blinded observer after three months, determining an improvement in the TUGT (response variable), other balance and mobility tests and functional level (TUGT Manual, TUGT Cognitive, OARS, Balance Scale, Functional Reach, CTSIB, balance reactive strategies and DGI-8) and falls. RESULTS: There was an improvement in the scores on all tests in the three groups. Statistically significant differences between groups were only found on the TUGT (p=0,035), with the greatest reduction in time required to perform the test among the workstation group. CONCLUSION: The findings of the present study suggest that participation in a weekly exercise program based on “workstations” is more effective than the other two programs evaluated regarding an improvement in balance and mobility in elderly individuals. However, further studies are needed in order to establish additional strategies that can sustain and maximize these benefits. / TEDE / BV UNIFESP: Teses e dissertações

Bakgrund: I rådande situation med Covid-19 har företag tvingats genomgå en digitalisering av deras verksamhet. Digitaliseringen har medfört att medarbetarnas arbetsstationer har genomgått en förändring från att tidigare jobba på kontor med sina kollegor runt sig och med sköna kontorsstolar till att numera arbeta på distans. Hur har detta påverkat medarbetarna och hur upplever de förändringen? Syfte: Syftet med studien är att bidra med en djupare förståelse för hur arbetsstationer har förändrats och vilka inverkningar det har på medarbetarnas upplevelser. Metod: Studien utgår från en kvalitativ metod och använt sig av semistrukturerade intervjuer för att få fram medarbetarnas upplevelser. Tio intervjuer har genomförts med två olika företag för att skapa ett större urval i respondenter. Analys: Medarbetaren upplever att det finns en materiell saknad gentemot innan förändringen. Där det tidigare på kontoren hade tillgång till allt som var relevant och aktuellt för att utföra arbetet. Medarbetaren upplever därför en avsaknad av materiella tillgångar i hemkontoret. Medarbetaren upplever att den nya arbetssituationen kräver mer av individen, vilket har lett till att medarbetaren upplever mer engagemang till arbetet, arbetsuppgifterna upplevs som mer meningsfulla, mer ansvar har resulterat i högre tillit från företagen vilket resulterat i att medarbetaren tagit mer initiativ och upplever ett roligare arbetssätt. Medarbetaren upplever också en positivitet till det mer flexibla arbetssättet och positivitet till den minskade distansen till kontoret. Däremot upplever medarbetaren en avsaknad av den sociala kontakten som tidigare fanns på arbetskontoret. Slutsats: Slutsatsen är att den digitala förändringens påverkan på arbetsstationen och medarbetaren, haft en positiv påverkan, där individen och medarbetaren har gynnats snarare än att missgynnas av förändringen. / Background: In current situations with Covid-19, companies have been forced to undergo a digitization of their operations. This has meant that the employees' workstations have undergone a change from previously working in offices with their colleagues around them and with comfortable office chairs to now working remotely. How has this affected the employees and how do they experience the change? Purpose: The purpose of the study is to create a deeper understanding of how workstations have changed and what impact it has had employees' experiences.Method: The study is based on a qualitative method and used semi-structured interviews to obtain the employees' experiences. Ten interviews were conducted with two different companies to create a larger sample of respondents. Analysis: The employees feels that there is a material lack compared to before the change. Where previously in the offices had access to everything that was relevant and current to perform the work. The employees therefore experience a lack of tangible assets in the home office. The employees feel that the new work situation requires more of the individual, which has led to the employee experiencing more commitment to the work, the tasks are perceived as more meaningful, more responsibility has resulted in higher trust from companies, which has resulted in the employee taking more initiative and experiencing more fun working. The employees also experience a positivity to the more flexible way of working and positivity to the reduced distance to the office. On the other hand, the employee experiences a lack of social contact that previously existed in the employment office. Conclusion: The conclusion is that the impact of digital change on the workstation and the employee has had a positive impact, where the individual and the employee have benefited rather than been disadvantaged by the change.

A power distribution design engineering workstation is used as the basis for a restoration management system. The complete system contains three separate programs. The three programs are the Telephone Operator program, the additions to the design workstation, and the statistical collection program. The use of graphical interaction as a method of improving the restoration process will be presented. A method of contextual based editing is presented as an aid to the workstation based program. Records of the outages are kept by the system. The outage records are used to create statistical tables for the representation of each set of stored data. / Master of Science

No description available.

No description available.

O problema de balanceamento de linhas de produção e designação de trabalhadores (ALWABP, do inglês Assembly Line Worker Assignment and Balancing Problem ) é uma extensão do problema simples de balanceamento de linhas na qual os tempos de execução de tarefas são dependentes dos trabalhadores. Este problema tem sua motivação prática oriunda de linhas de produção com trabalhadores deficientes. Neste trabalho, focamos em uma extensão para o problema que permite lidar com a possibilidade de layouts de linhas com estações em paralelo. Além disso, estudamos uma segunda variante do problema que permite que os trabalhadores colaborem uns com os outros em uma mesma estação. Apresentamos formulações matemáticas para ambas as versões do problema. Adicionalmente, a partir de adaptações de métodos existentes para o ALWABP serial, desenvolvemos heurísticas construtivas para o ALWABP paralelo e ALWABP colaborativo. Testes computacionais em instâncias da literatura e uma análise detalhada dos resultados são apresentados / The assembly line and worker assignment balancing problem is an extension of the classical simple assembly line balancing problem where task execution times are workerdependent. This problem is motivated by the situation faced when balancing assembly lines with disabled workers. In this study, we focus on an extension for the problem with the goal of including the possibility of having layouts with parallel workstations. We also study a second variation for this problem that allows workers collaborating with each other. We present mathematical formulations for both problems. Moreover, constructive heuristics are developed, based on heuristic methods for the serial assembly line worker assignment and balancing problem. Computational tests on literature instances and a detailed analysis of the results are reported

The mixing desk metaphor found in Digital Audio Workstations (DAW) is built upon a specialised and technical knowledge of signal flow and audio engineering. However, since their inception the DAW has gained a far wider and less technically specialised user-base. Furthermore, the limited screen space of laptop and tablet computers, combined with potentially limitless tracks in current DAWs has resulted in the need for complex interface navigation during mixing which may inhibit a fluid and intuitive approach to mixing. The research outlined in this thesis explores novel designs for Graphical User Interfaces (GUIs) for mixing, which acknowledge the changing role of the user, the limited space of tablet and mobile computers screens and the limitations of human perception during cross modal activities (aural and visual). The author designs and conducts several experiments using non-expert participants drawn from several music technology courses, to assess and quantify the extent to which current DAW designs might influence mixing workflow, aiming our research especially at beginner and non-expert users. The results of our studies suggest that GUIs which load visual working memory, or force the user to mentally integrate visual information across the interface, can reduce the ability to hear subtle simultaneous changes to the audio. We use the analysis of these experiments to propose novel GUI designs that are better suited to human cross-modal perceptual limitations and which take into account the specific challenges and opportunities afforded by screen-based audio mixers. By so doing, we aim to support the user in achieving a more fluid and focused interaction while mixing, where the visual feedback supports and enhances the primary goal of attending to and modifying the audio content of the mix. In turn, it is hoped this will facilitate the artistic and creative approaches required by music computer users.

This paper describes an approach to supporting work in the office. Using and extending ideas from the field of Artificial Intelligence (AI) we describe office work as a problem solving activity. A knowledge embedding language called Omega is used to embed knowledge of the organization into an office worker's workstation in order to support the office worker in his or her problem solving. A particular approach to reasoning about change and contradiction is discussed. This approach uses Omega's viewpoint mechanism. Omega's viewpoint mechanism is a general contradiction handling facility. Unlike other Knowledge Representation systems, when a contradiction is reached the reasons for the contradiction can be analyzed by the deduction mechanism without having to resort to a backtracking mechanism. The Viewpoint mechanism is the heart of the Problem Solving Support Paradigm. This paradigm supplements the classical AI view of problem solving. Office workers are supported using the Problem Solving Support Paradigm. An example is presented where Omega's facilities are used to support an office worker's problem solving activities. The example illustrates the use of viewpoints and of Omega's capabilities to reason about it's own reasoning process.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 147-155). Also available via the Internet.