Estabelecimento e utilização de uma plataforma diffserv gerida por um Bandwidth Broker

Apresentação efectuada na Conferência sobre Redes de Computadores - Protocolos, Tecnologias e Aplicaçoes para Ambientes Moveis, 6, Bragança, Portugal, September 2003.O Bandwidth Broker (BB) é uma entidade central que num domínio de Serviços Diferenciados realiza o controlo de admissão através da gestão e supervisão global dos recursos disponíveis, podendo também controlar e regular o tráfego aí existente. Este artigo descreve o estabelecimento de uma plataforma experimental gerido por um BB e apresenta um conjunto de testes, realizados com tráfego UDP e TCP, que permitirá avaliar a operacionalidade da plataforma e a importância da utilização do BB na manutenção da QoS requerida pelas aplicações

A Model to Improve the Accuracy of WSN Simulations

Simulation studies have been extensively adopted in the networking research community. Nevertheless, the performance of the software components running within the network devices is often not modeled by generic network simulators. This aspect is particularly important in wireless sensor networks (WSN). As motes present very limited computing resources, the overhead of the software components cannot be ignored. Consequently, WSN simulation results may diverge significantly from the reality. After showing experimentally the validity of this assumption, the paper proposes a set of generic equations to model the performance of WSN software components. Validation tests using contention and multiplexing-based MAC protocols show that the inclusion of the proposed model in a WSN simulator improves the confidence degree in the simulation results significantly

Modelling the impact of software components on wireless sensor network performance

Network Simulators are often used to study multiple aspects of data communications in distinct scenarios, including wireless sensor networks (WSN). However, the performance of the software components running in the network nodes is normally neglected by the simulators. This aspect is particularly important in WSNs, as nodes have very limited computing resources. In order to study the impact of software components on WSN performance, a simulated WSN and a physical WSN were setup in the IEEE 802.15.4 domain. Tests revealed that the simulator must take into account the software components of the WSN to produce realistic results. To achieve this, new parameters are proposed to model the impact of the software components on a physical WSN. Tests measuring the packet round-trip delay, delivery error ratio, and duplicated packet ratio showed that the inclusion of this model in a simulator improves significantly the accuracy of the results when compared with those obtained in a physical WSN

A time-slot scheduling algorithm for e-health wireless sensor networks

http://www.ieee-healthcom.org/2010/about.htmlFor e-health wireless sensor networks presenting significant traffic loads, MAC protocols based on deterministic scheduling algorithms are consensually considered more adequate than protocols based on random access algorithms. Indeed, TDMA-based MAC protocols are able to control the delay bound and save power by eliminating collisions. However, these protocols always require some expedite scheme to assign the superframe time-slots to the network devices that need to transmit data. Knowing that patients of an e-health wireless network are normally monitored by the same number and types of motes, originating a regular traffic pattern, a simple collaborative time-slot allocation algorithm can be achieved, as introduced in this paper. In the proposed algorithm, the announcement of time-slot allocation by the network coordinator is avoided, which helps to improve the packet delivery ratio and reduce the energy consumption in the e–health wireless network.(undefined

Invariant measures for gauss maps associated with interval exchange maps

An explidt formula for an ergodic cr-finite measure inva.ria.nt by the Gauss map associated to a new induction on the interval exchange maps is given. The techniques devcloped allow another proof of Keane's conjecture which was first shown to be true by Veech and Mazur

Laser surface texturing of stainless-steel cutlery to integrate ceramic blocks: parametric optimization and patterning

Dynamic and fast-changing designs for cutleries or flatware are one important nature of this production business. Globalized hospitality merchandise, the demanding nature of modern customers, throat-to-throat competition of manufacturing industries, and the modernization of the manufacturing processes are some of the major challenges for the cutlery (silverware) manufacturing industry. So far, traditional methods of moulding and shaping are considered to be the best to provide static designs and trademark patterns of the organisation. Preparing a designed mould for a fixed blueprint of cutlery and then producing it in bulk is the sole purpose of existing methods. However, with the invention of laser engraving and design systems, the entire business of cutlery production has revolutionized. Allowing for different designs for different cutleries to set without changing the whole production line was the aim of this study. As shown in Figure 1, AISI-304 stainless steel, which is the general flatware material selected for laser engraving, was evaluated with three most vital input parameters (power, scanning speed and loops or number of passes) followed by the analysis of geometry, roughness, and volume removed/material removal (MR) as output variables. This study will provide insight into the know-how situation involving the processing of cutleries and introduction of different ceramic materials to the surface to define desired patterns. We produced different design patterns by laser and ingrained ceramic blocks on the silverware. This approach is much more flexible and adoptable for pattern changes. Besides that, there is no need to prepare a mould for each design. Belo Inox, Portugal supplied the silverware as per the collaborative project agreement.publishe

Wireless sensor networks with QoS for e-health and e-emergency applications

http://www.informatik.uni-trier.de/%7Eley/db/conf/icsoft/ehst2008.htmlMost body sensor networks (BSN) only offer best-effort service delivery, which may compromise the successful operation of emergency healthcare (e-emergency) applications. Due to its real-time nature, e-emergency systems must provide quality of service (QoS) support, in order to provide a pervasive, valuable and fully reliable assistance to patients with risk abnormalities. But what is the real meaning of QoS support within the e-emergency context? What benefits can QoS mechanisms bring to e-emergency systems, and how are they being deployed? In order to answer these questions, this paper firstly discusses the need of QoS in personal wireless healthcare systems, and then presents an overview of such systems with QoS. A case-study requiring QoS support, intended to be deployed in a healthcare unit, is presented, as well as an asynchronous medium access TDMA-based model

OBSERVATÓRIO DA EDUCAÇÃO: DELINEAMENTO DOS INDICADORES DE DESEMPENHO PARA CONSTRUÇÃO DE UM MAPA ESTRATÉGICO PARA PROGRAMAS STRICTO SENSU EM ADMINISTRAÇÃO, CIÊNCIAS CONTÁBEIS E TURISMO EM IES DO ESTADO BRASILEIRO DO PARANÁ

Este estudo lança um olhar sobre a demanda cada vez maior por cursos de pós-graduação stricto sensu no Brasil, se faz necessária uma ampliação desse tipo de programa, para tanto essa expansão deve esta em sintonia com as ultimas três décadas onde foram consolidadas estruturas bem definidas e criteriosas de avaliação para esse tipo de programa. Essa artigo tem por objetivo delinear essa rede de indicadores de desempenho estabelecidos pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), definindo um mapa estratégico na tentativa de viabilizar de forma sustentável a progressão dos programas de pós-graduação stricto sensu em administração, contabilidade e turismo do estado brasileiro do Paraná. Para tanto, procedeu-se uma pesquisa em oito programas reconhecidos e recomendados pela CAPES.Utilizando o método de estudo qualitativo, a pesquisa pode se caracterizar como um estudo descritivo, exploratório, onde foi possível evidenciar com a maior exatidão possível os fatos e fenômenos da situação em estudo.Como resultado foi possível chegar aos indicadores e a construção de um sistema de informação estruturado para gerenciar todo o processo de acompanhamento e gestão dos indicadores utilizando ferramenta de tecnologia da informação

Trade-off analysis of a MAC protocol for wireless e-Emergency systems

Wireless sensor networks are envisioned to be deployed in healthcare. Since emergency and intensive care applications need to assure reliable and timely data delivery, they have increased demands for quality of service, including at the MAC layer. Amongst MAC protocols available for WSNs, the Low Power Real Time (LPRT) presents suitable characteristics to be deployed in emergency platforms due to its rational bandwidth allocation, low energy consumption, and bounded latency. Yet, this protocol may present a significant packet loss ratio in a wireless channel with bit error ratio. In order to define a MAC protocol more robust to bit error conditions and able to fulfill the required quality of service, solutions based on short size beacons and multiple retransmissions are proposed and tested. The results showed that such strategies led to meaningful improvements regarding packet loss ratio, without compromising significantly the energy consumption.Fundação para a Ciência e a Tecnologia (FCT

An improved MAC Protocol with reconfiguration scheme for Wireless e-Health Systems requiring quality of service

To provide a reliable assistance to patients, emergency and intensive care systems have increased demands for quality of service at different levels, including at the MAC layer. The Low Power Real Time (LPRT) MAC protocol presents suitable characteristics to address these demands due to its efficient bandwidth allocation, low energy consumption, and bounded latency. Yet, this MAC protocol may still present a significant packet loss ratio in a wireless channel affected by errors. In order to improve its robustness to bit error conditions, a solution based on short size beacons is proposed and tested. Results show that significant improvements regarding packet loss ratio and energy saving are obtained. A new reconfiguration scheme is also proposed so that a WSN using this solution may react optimally in accordance with the patients' clinical state.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/34621/200