Made available in DSpace on 2015-05-14T12:36:51Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1355559 bytes, checksum: fe1c88470e43ce75f706ec9d15cc7bb1 (MD5) Previous issue date: 2014-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / With the advent of technological advances, increasingly demand solutions that use fewer resources, are faster and low cost. As a result, this paper proposed a hybrid approach using metaheuristics Greedy Randomized Adaptive Search Procedure (GRASP) and Iterated Local Search (ILS) applied to the Response Time Variability Problem (RTVP). Since this problem may involve allocation of scarce resources, such as industrial machinery or meeting rooms, going for scheduling of banking customers that require certain conditions, planning of TV ads or route taken by vehicles of logistic companies, etc. For application of the procedure, the movements of shifting symbols, swapping positions between symbols and one called double bridge, which is a mix of movements of shifting and swapping involving opposite symbols were used. The neighborhood structures were based on the movements described above, varying the number of symbols involved. Thus, the results obtained demonstrate that such procedures satisfied the problem and brought consistent results when compared with the literature. / Com o advento dos avanços tecnológicos, cada vez mais se procura soluções que utilizem menos recursos, sejam mais rápidos e de baixo custo. Em virtude disso, este trabalho propôs uma abordagem meta-heurística híbrida utilizando Greedy Randomized Adaptive Search Procedure (GRASP) e Iterated Local Search (ILS) aplicados ao Problema da Variabilidade do Tempo de Resposta. Este problema pode envolver desde alocação de recursos escassos, como por exemplo, máquinas industriais ou salas de reunião, passando pelo agendamento de clientes de um banco que requerem certas condições, o planejamento das propagandas de TV ou o percurso feito por caminhões de empresas transportadoras, dentre outros. Para a aplicação do procedimento, foram utilizados os movimentos de deslocamento do mesmo, permuta de posição entre símbolos e de um movimento chamado double brigde, que é uma mistura dos movimentos de deslocamento e permutação envolvendo símbolos opostos. As estruturas de vizinhança compostas basearam-se nos movimentos descritos anteriormente, variando a quantidade de símbolos envolvidos. Desta forma, os resultados obtidos demonstram que tais procedimentos trouxeram resultados satisfatórios ao problema e condizentes quando comparados com a literatura.

Web applications are often described as being cross-platform. They are accessible from a multitude of different web browsers, which in turn are running on a multitude of different operating systems. For a time now, developers have used many different tools to create cross-platform applications for mobile devices with web technologies. However, these applications fail to deliver when taken out of their native environment, and often do not feel native at all. Enter Progressive Web Applications, PWA. PWA’s are applications written for the web with web technologies, running in a browser,  but seasoned with some techniques that can make them behave like a native application when running on a mobile device. They are just ordinary web applications with native behaviour such as offline support, installability, and push notifications. The question that arises is - can this new type of web applications match Native Android Applications in performance, especially the response time when accessing the device's hardware? This report will try to answer that question

In this study,   the purpose is to measure how much the response time affect the effectiveness   and usability of the user on e-commerce pages, and to evaluate whether   displaying a loading symbol affects the user's opinion positively or   negatively. This study is based on three theories, Nielsen's (2010) theory of   how response time affect users effectiveness, Galetta et al. (2004) theory of   how response time affect users' attitude towards the side and Hong et al.'s   (2013) theory if users' perception of the response time is influenced by   displaying a symbol while loading. The empirical method used to collect the   data is two different quantitative methods. The data that form the basis of   the study has been collected by allowing users to carry out test purchases via   an e-commerce site and via a survey that was shown at the end of the   purchase. A total of 126 users chose to start the test, of which 96 chose to   complete the test purchase and responded to the survey. The users were   divided into six different groups, each group receiving a fixed delay   assigned as constant throughout the test purchase. The fixed delays assigned   to the different groups were 0 ms, 2000 ms, 4000 ms, 6000 ms, 8000 ms, 10 000   ms and 12 000 ms. The result found in the study is that all three theories   could be validated using the empirical study that was used. The conclusion   that can be drawn is the user's efficiency decreases as response time   increase. The users' attitude towards the side decreases as response time   increase. The loading symbol has a positive impact on users regarding long   response time, as it has a negative impact on those users with short response   time. The breaking point where the majority of users' efficiency dropped, the   negative attitude increased and the loading symbols had the greatest impact   occurred at 6000 ms delay.

Los servicios web son considerados por la industria y la investigación de facto por proporcionar funcionalidad de forma distribuida que sea usable en entornos heterogéneos. En pocas palabras, los servicios web son funcionalidad empaquetada que se basa en un conjunto de estándares que facilitan la definición de los métodos de los servicios web, sus números y formatos de entrada, así como sus números y formatos de salida. En combinación con la replicación, los servicios web pueden proporcionar soluciones de optimización del rendimiento a un número ilimitado de aplicaciones de negocio de la vida real. Sin embargo, cuando se habla de replicación es necesario plantearse cómo asignar o elegir las réplicas para proporcionar el mejor rendimiento posible. Esta tesis está dedicada a responder a esta pregunta. La tesis se titula "Un mecanismo de asignación de servicios web basado en Broker" donde un paradigma de ejecución (Proteus) es presentado, y varios algoritmos de asignación son también presentados, examinados y analizados para mostrar el óptimo. La tesis se centra en el componente broker del paradigma de ejecución. Este componente tiene embebido el algoritmo de asignación. Por otra parte, la tesis se centra en el Algoritmo de menor tiempo de servicio (LRT), el cual funciona asignando las réplicas del servicio web que proporcionan un tiempo de respuesta más rápido. La tesis ofrece todo el trabajo de fondo necesario, así como toda la investigación relacionada. Contiene una parte simulada, así como una descripción de un sistema de la vida real (Proteus). Contiene también una sección dedicada a analizar los resultados de los registros de ejecución y analizar las diferentes variaciones de los entornos (homogéneos y heterogéneos), el número de replicas y el nivel de paralelismo. Los registros son examinados y las conclusiones expuestas. / Alwagait, EAK. (2011). A Broker based Web Service Allocation Mechanism [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/12500 / Palancia

No description available.

The thesis deals with design of a semiactive seat suspension system for an agriculture machines and design of dynamic model of the system, which includes real parameters of a magnetorheological (MR) damper. The dynamic model is a single degree of freedom model and it is made in program Matlab. In the model, response time of the MR damper and three control algorithms are implemented (two-state Skyhook, Skyhook linear approximation damper control and Acceleration Driven Damper control). Based on the results of the simulations, the damping characteristics are defined, and the MR damper is modified to achieve fast response time. A test seat is designed to test transmission of vibrations to the driver. The simulation results provide a comparison of efficiency of the seat suspension depending on the response time and control algorithm, as well as a comparison with a passive suspension system. On the designed test seat with MR damper with a fast response time, the vibration transmission is reduced up to 25 % compared with the best passive seat suspension setup.

Wave Energy Converters (WEC) are used to transform energy stored in ocean waves into electrical energy. One type of WECs consists of buoyant bodies. To extract energy from their motion, hydraulic cylinders can be used to generate hydraulic power. For conversion into electric power various systems have been analysed in literature. However, the focus was put on efficiency and rigorous analyses of the system behaviour are still missing. In this paper an exemplary system consisting of two hydraulic cylinders, switchable check valves, accumulators and three motor-generator sets is analysed with help of simulation and measurement. This exemplary system is called WavePOD and was installed at the Institute for Fluid Power Drives and Controls (IFAS) of RWTH Aachen University together with Aquamarine Power and Bosch Rexroth for testing. In this paper the data collected during various test phases is used for system analysis and for validating the simulation. The simulation model is presented. The system’s response to various switching operations is investigated. Comparing the simulation with measurements validates the system`s dynamic model.

The increase of the Industrial Internet of Things (IIoT) and Industry 4.0 led to many interconnections in the control systems. IIoT has begun its evolution and development in the scientific community and industrial application field. As communication between IIoT devices and other equipment needs to be implemented through the network, it is necessary to provide reliable and straightforward data transmission. This thesis investigates how to develop a middleware that provides connectivity between specific industrial environments. Particularly, a prototype design is created to connect an industrial controller with information of interest using the Message Queuing Telemetry Transport (MQTT) protocol. We set up experiments to evaluate the features of the implemented prototype. The experiment examines the effect of the developed prototype's end-to-end response time and scalability characteristics by receiving a different number of messages from the stimulator. By measuring the end-to-end response time, the experiment showed that in the case of many input/output (I/O) signals arriving in the connectivity service, the implemented prototype is well scaled under examined circumstances. Observing the results, the middleware prototype gave acceptable results in terms of response time. Also, it gave us a picture of how different network settings can cause a difference in estimating the end-to-end response time of a message.

No description available.

No description available.