919 research outputs found

    Extração automática de candidatos a termos para criação de um mapa conceitual do domínio de intensificação agropecuária.

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    O objetivo deste trabalho é extrair automaticamente os candidatos a termos de um córpus do domínio Intensificação Agropecuária, para subsidiar e facilitar a criação de um mapa conceitual deste domínio.Trabalho apresentado na V Mostra de Trabalhos de Estagiários e Bolsistas, Campinas, out. 2009

    Evaluation Technique for The Failure Life Scatter of Lead-Free Solder Joints in Electronic Device

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    Recently, the electronic device equipment using a semiconductor is widespread to all industrial fields. Solder is used to mount electronic parts, such as resistors and capacitors, on printed-circuit boards in almost all electronic devices. However, since in many cases the thermal expansion coefficients of electronic parts and PCBs are different, cyclic thermal stress and strain causes solder fatigue and device failure. Especially in the power electronic module and car electric module, the evaluation of thermal fatigue life is important. It is understood that the fatigue life of some electronic devices shows large scatter in the thermal cycle test, even if their design is the same. The dispersion of design factors such as shape, size and material properties of solder joints is thought as one of these reasons. Moreover, in the case of chip components, it is thought that the interacting effect by the structural asymmetry due to the unbalance solder joints would influence reliability. At the same time, the changeover from eutectic Sn-Pb solder to lead-free solder has been driven by environmental concerns. Therefore, it cannot be disregard as the main factor of the reliability evaluation in the solder joints. In this study, how the dispersion of design factors and the interacting effect between the design factors influences the fatigue life in lead-free solder joint was investigated by the analytical approach. It is understood that the thermal fatigue life of solder joints can be estimated by the inelastic strain range obtained from the FEM analysis. Recently, it is demanded to evaluate the final failure life of electronic components. So, it is necessary to evaluate not only crack initiation but also crack propagation. In this study, crack propagation analysis was carried out by using a new approach and the failure life was evaluated on the basis of Manson-Coffin's law and Miner's rule. Moreover, sensitivity analyses were carried out to study the main effect of the dispersion of each factor on solder joints. And then, the interacting effect between the factors on the reliability was studied by considering the structural asymmetry due to the unbalanced solder joints. As a result, a practical evaluating technique for the failure life scatter of solder joints was proposed

    Fibrosis Evaluation by Transient Elastography in Patients With Long-Term Sustained HCV Clearance

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    BACKGROUND: Reversibility of advanced fibrosis after HCV-clearance is an important goal of therapy. OBJECTIVES: Measuring liver stiffness (LS) by transient elastography (TE) might be helpful in this setting. PATIENTS AND METHODS: We evaluated 104 patients with biopsy-proven chronic hepatitis C (CHC) and sustained virological response (SVR) after Peg-Interferon (IFN) plus ribavirin since at least 18 months. HCV-eradication was confirmed searching for serum HCV-RNA (TMA® sensitivity > 5-10 IU/ml). Data from literature reported the best LS cut-off values for different stages of liver fibrosis were 7.1 kPa for Metavir stage 2 (F2), 9.5 kPa for F3 and 12.5 for cirrhosis (F4). RESULTS: TE was not reliable in four SVR obese patients. Metavir-stage of biopsy was F0-1 in 28, F2 in 47, F3 in 17 and F4 in eight patients. The median interval elapsed since achieving SVR was 36 months (range: 18-77, SD¬¬:18). Stratifying patients according to the histological stage assessed before treatment, a clear-cut gradient of LS values was observed from F0-1: median: 3.8 kPa (range: 3.5-4.9) to F2: 4.6 kPa (3.8-6.0), F3: 6.2 kPa (4.8-8.6) and F4: 8.4 kPa (6.2-9.2) (P = 0.001). Overall, 86 patients had lower values of LS than the expected LS values according to Metavir-stage. At multivariate logistic analysis γ-GT and histological steatosis were independently associated with persistence of higher values of LS. CONCLUSION: Long term responders to IFN-based therapies have lower LS values than those who are untreated and still viraemic. High levels of γ-GT and liver steatosis, all markers of insulin resistance, may hamper reduction of liver stiffness after HCV-clearance

    Segmenting Motion Capture Data Using a Qualitative Analysis

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    Many interactive 3D games utilize motion capture for both character animation and user input. These applications require short, meaningful sequences of data. Manually producing these segments of motion capture data is a laborious, time-consuming process that is impractical for real-time applications. We present a method to automatically produce semantic segmentations of general motion capture data by examining the qualitative properties that are intrinsic to all motions, using Laban Movement Analysis (LMA). LMA provides a good compromise between high-level semantic features, which are difficult to extract for general motions, and lowlevel kinematic features, which often yield unsophisticated segmentations. Our method finds motion sequences which exhibit high output similarity from a collection of neural networks trained with temporal variance. We show that segmentations produced using LMA features are more similar to manual segmentations, both at the frame and the segment level, than several other automatic segmentation methods
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