Search

In mechanomyography (MMG), there seems to be more studies in isometric contractions than isokinetic ones. MMG amplitude can be used to track torque decline in fatiguing isokinetic contractions. This study aims to determine good MMG/torque correlation indicators. Three volunteers performed 50 isokinetic contractions at 300°s−1. The MMG acquisition system is based on a triaxial accelerometer sensor. It was positioned on the belly of the rectus femoris muscle. The acquired RMS and derived signals were first analyzed for determining whether they have normal distribution. Then, the linear correlation coefficients were calculated. Sensor's axis 1 presented weaker correlation with torque variables than axis 2 and 3. The modulus of the three signals (axes 1, 2, and 3) had the highest correlation values. The RMS MMG amplitude had better correlation with RMS torque than peak torque. However, with the averaged values, correlation coefficients were R=0.89 and R=0.89 (p<0.01) for peak torque and RMS value, respectively. Two main conclusions were drawn: the modulus is a good indicator of torque amplitude in isokinetic contractions at 300°s−1, and peak torque and maximum RMS torque values occur after the first extension. However, tests with more volunteers are needed in order to precisely assess these results. [ABSTRACT FROM AUTHOR]

The reduction of the noise generated by jet-engine aircrafts is of growing concern in the present society. A better understanding of the aircraft noise production and the development of predictive tools is of great interest. Within this framework, the CoJeN (Coaxial Jet Noise) European Project includes the measurement of the flow field and the noise generated by typical turbofan jet-engine nozzles. One of the many aspects of interest is the occasional presence of acoustic tones of a defined frequency, symptomatic of the presence of quasiperiodic coherent structures within the flow. This chapter analyzes the characteristics of a vortex street in the core-bypass lip of one of the nozzles under study. The measurements were made by means of advanced PIV techniques within the above-mentioned project. [ABSTRACT FROM AUTHOR]

The Revolution of 25 April 1974 was a great milestone of change with obvious consequences for the historical development of schooling in Portugal. Putting an end to a forty-eight-year-old dictatorship, it opened the country to democracy. After Salazar's death in 1968, the new Prime Minister, Marcello Caetano, tried to gradually reform the regime, but the so-called Marcellist spring was so weak and corrupt that the Revolution broke out in the early morning hours of 25 April 1974. It was the army, tired of a bloody and futile war in remote colonies in Africa, that led the Revolution (also known as the Carnations Revolution, because these flowers were in bloom at that time of the year and were placed in the guns of the soldiers). It was a peaceful revolution, since the forces of the ancien régime surrendered with little resistance. [ABSTRACT FROM AUTHOR]

In the present work, Tillandsia usneoides L., an epiphytic bromeliad, was used as bioindicator of atmospheric metal pollution in São Paulo, Brazil, the biggest city in South America. Tillandsia samples were collected from an unpolluted area and were exposed bimonthly at ten sites of the city with different pollution levels and at a control site. Seven trace metals (Ni, Co, Cu, Cd, Pb, V, and Sb) were analysed in the plants by inductively coupled plasma mass spectrometry (ICP-MS) thereafter. The results indicated that Co, Ni, Cd, and V can be attributed to industrial sources while Cu can be associated to both vehicular and industrial sources. Sb is suggested to be influenced mainly by vehicular sources. For Pb, no evident sources could be identified so far as it was spread evenly along the monitoring sites. [ABSTRACT FROM AUTHOR]

The Chaudanne stream received urban inputs discharged through combined sewer overflows (CSOs). The water quality was not severely impaired, with pollution mainly of organic origin. Oligochaete assemblages were studied in the coarse surface sediments and the hyporheic zone and sampled at four sites on seven occasions during 2000 and 2001. The seasonal distribution of oligochaete assemblages was analyzed by a PCA, the oligochaete species being assigned to functional traits (FTrs). Site 1, located upstream of the CSOs, was characterized by FTrs 1 and 2 (species indicating permeability and those intolerant to water pollution). Below the CSOs, high densities of oligochaetes occurred in the benthic layer of sites 3 and 4, with a predominance of FTr3 (species with tolerance to water pollution). At site 4, FTr4 species (indicative of sludge conditions) constantly predominated in the hyporheic system, but predominated in the benthos only during low stream discharges associated with peaks in CSOs. FTr3 was related to amounts of the oxidized forms of nitrogen, high stream discharges and probably to groundwater upwellings and the sludge tolerant species group (FTr4) was associated with high NH4+ contents. We are now testing the relevance and generalization of this new approach. [ABSTRACT FROM AUTHOR]

This article merges two approaches: one dealing with persistence for logic programs, as provided by a relational database back-end and another which addresses the issues of logic program structuring, by way of the parametric context. We claim that these two can be effectively combined to obtain a language which offers significant gains in expressiveness over previous work. This claim is experimentally backed by the applications that have been developed using these tools. [ABSTRACT FROM AUTHOR]

This paper presents a set of rules for extracting noun phrases from Portuguese texts. We describe how this set was gradually obtained, starting from a machine learned set of transformation rules that was manually reviewed. The noun phrases extracted by these transformations were given as input to another learner that synthesized rules for breaking up complex noun phrases into simpler ones. The results of these processes applied to a Brazilian Portuguese corpus are evaluated. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) are employed in different domains and applications. The resource constraint on such networks, many times composed of hundreds to thousands of devices, and the requirement of autonomous operation become their management a challenging task. This work applies policies, a well-known approach in network management, in the core task of routing in autonomous WSNs. Policies are used to establish rules to take dynamic actions on the network according to its state. Our scheme offers a high-level and flexible way to realize management tasks related to routing in WSNs, which can be defined in a progressive way as knowledge from the environment is acquired or application requirements change. Case studies employing a policy-based adaptive hybrid solution allows the autonomous selection of the best routing strategy in view of network conditions and application requirements. Simulation results show the benefits and resource savings offered by the use of policies for adaptive routing in WSNs. Keywords: Wireless Sensor Networks, Routing, Policy-based design. [ABSTRACT FROM AUTHOR]

The traffic management of IP networks faces increasing challenges, due to the occurrence of sudden and deep traffic variations in the network, which can be mainly attributed to the large diversity of supported applications and services, to the drastic differences in user behaviors, and to the complexity of traffic generation and control mechanisms. In this context, active traffic measurements are particularly important since they allow characterizing essential aspects of network operations, namely the quality of service measured in terms of packet delays and losses. The main goal of the work presented in this paper is the performance characterization of operational networks consisting in heterogeneous environments including both wired and wireless LANs, using active measurements. We propose a measurement methodology and its corresponding measurement platform. The measurement methodology is based on the One-Way Active Measurement Protocol (OWAMP), a recent proposal from the Internet2 and IETF IPPM groups for measuring delays and losses in a single direction. The measurement platform was implemented, tested and conveniently validated in different network scenarios. Keywords: Network management, traffic monitoring, active measurement, OWAMP. [ABSTRACT FROM AUTHOR]

The digital inclusion promotes the reduction of social inequalities. Based on this principle, the Brazilian Government has been setting up an increasing number of Web access locations to render virtual support to its citizens. However, there are no guidelines for the construction and assessment of these electronic Government (e-Gov) sites. In this article we measure the web site quality in the e-Gov domain with the following proprieties: usability, accessibility, interoperability, security, privacy, information reliability, and service agility. We implemented our method, by using a checklist tool, in the evaluation of 127 Brazilian government sites (federal, state and municipal). Our method proved itself efficient in the diagnosis and identification of specific problems in the e-Gov site domain. [ABSTRACT FROM AUTHOR]

Wireless Sensors Network are generally designed with hundreds or thousands of autonomic devices called sensor nodes. These sensor nodes organize themselves in a wireless ad hoc network that performs data sensing, processing and dissemination services. A wireless sensor network should perform, besides services related to the applications, self-management services with the goal to promote productivity and quality of service. In this work we have developed and evaluated management services related to the formation of groups and sensing area coverage maintenance, defined by the MANNA architecture, using a set of policies. The results show that this set of policies can lead to more productive sensor networks. [ABSTRACT FROM AUTHOR]

Grid technology is used for large-scale resource sharing among different institutions or individuals. A recent challenge in this environment is to provide guarantees for the service delivery in a job submission. It is important to know when a job will finish and the performance and costs involved. We present here a multi-agent system that considers such aspects to decide about the best place to run a job in grid. The main component of our solution is the negotiation process, which relies on resource access policies and performance prediction based on past cases of job submissions. The negotiation final goal is to establish Service Level Agreements that register user's expectations and service provision according to price, quality, performance and scheduling. [ABSTRACT FROM AUTHOR]

In this paper, a distributed computational system for finite element structural analysis and some strategies for improving its efficiency are described. The system consists of a set of programs that performs the structural analysis in a distributed computer network environment. This set is composed by a pre-processor, a post-processor, a program responsible for partitioning the model in substructures, and by a structural analysis parallel solver. The domain partitioning is performed interactively by the user through a graphics interface program (PARTDOM). An existing FEM code, based on object oriented programming concepts (FEMOOP), has been adapted to implement the parallel features. Different implementation aspects concerning scalability and performance speed-up are discussed. The computational environment consists of a 100 Mbit Fast-Ethernet network cluster including eight Pentium 200 MHz micro-computers running under LINUX operating system. [ABSTRACT FROM AUTHOR]

From the clinical point of view, the conditions associated with recurrence in the transplanted kidney can be classified into 3 groups: (i) inherited inborn errors of metabolism (IEM), (ii) systemic diseases with multiple organ involvement and (iii) glomerulonephritis [1]. Organ transplantation has been introduced during the last 15 years as a possible therapy of IEM. Such a management requires an accurate diagnosis, an early intervention in most cases and a precise knowledge of the biochemical defect. Because of the possible consequences and risks of transplantation, the place of organ replacement is the following issue of conventional therapy of IEM, i.e. treatment at the clinical phenotype level, at the metabolic level and at the dysfunctional protein level [2]. In most cases, transplantation provides the normal protein in its physiological cellular and subcellular locations with respect to its substrates and cosubstrates. Four main conditions can be considered (Tables 1 and 2): (1) transplantation as a replacement of an isolated damaged target organ, such as kidney in nephropathic cystinosis or heart in familial hypercholesterolemia; (2) transplantation as a source for a deficient protein such as displacement marrow transplantation in lysosomal storage diseases or orthotopic liver transplantation in primary hyperoxaluria type 1 (PH1); (3) transplantation as a concommittent protein source and replacement of damaged organ, such as liver transplantation in α-antitrypsin deficiency or tyrosinemia type 1; (4) in cases of combined transplantation, another organ has to be grafted as a replacement of the damaged native one, such as liver + heart in familial hypercholesterolemia or liver + kidney in PH1 [2]. [ABSTRACT FROM AUTHOR]

Intelligent task planning executed by manipulators robots and mainly its integration with the development of efficient controllers responsible for the execution of these tasks, constitute a non completely well solved problem, for sure needing more researches. In this way, it was created two computational tools: NONLinear Intelligent Planner (NONLIP), and the Simulator with Inter-face for Manipulators (SIM). Good results have been achieved in a general way for all simulated situations. This permit to conclude that the proposed formula-tions can be implemented in a practical device since the simulations use realis-tic models validated experimentally. [ABSTRACT FROM AUTHOR]

Magnetic Resonance Imaging (MRI) is an important tool for diagnosing meniscal injuries. The use of improper techniques may compromise the diagnose. The typical protocols used to diagnose meniscal injury are conventional Spin Eco and Fast Spin Eco. This work compare both techniques using a computational program developed in JAVA. The analyses performed include the comparison of image sharpness, tissue distribution and the determination of the size of the harm obtained with each acquisition technique. The results showed the superiority of conventional Spin Echo techniques for diagnosing meniscal lesion. [ABSTRACT FROM AUTHOR]

A multidisciplinary methodology was performed in order to characterize suspended particulate matter PM10 levels in Lisbon, and its impact on human health. Four PM10 measuring campaigns were developed: background levels distribution, outdoor versus indoor levels, maximum levels at traffic hotspots and personal exposure assessment. Receptor modelling methods were applied to aerosol samples from Alfragide (near Lisbon), in 2003. Another task developed within the modelling field was a health impact assessment for Lisbon using PSAS-9 model, model used by the French Public Health Institute to assess the impact of atmospheric pollution, in general, and PM levels in particular. [ABSTRACT FROM AUTHOR]

In the last decades the number of information centers that receive data from different origins or technologies has increased enormously. Representing and reasoning with temporal data is an important issue in the majority of those centers. Nevertheless, most of the solutions to solve such issue are rather limited and specific to a certain domain. [ABSTRACT FROM AUTHOR]