1,722,475 research outputs found
Numerical and Experimental Analysis of Fan-induced Flow and Heat Transfer in Electronic Systems
No full textTorque transmission capability of composite-metal interference fit joints
No full textIn this paper the performance of an interference fit joint between a composite tube and a steel shaft under torsional load was investigated. Some important design parameters on the interference fit joint were presented and addressed based on the results from analytical and numerical models. The stress state of the joint under torsional load with contact elements was calculated by three dimensional finite element analysis. For the long term use of the interference joint the viscoelastic behavior of the composite tube was also considered through the analytical model. Finally the validity of analysis of the interference fit joint was experimentally examined. (c) 2005 Elsevier Ltd. All rights reserved
Motion field segmentation under the 3-D movement of rigid planar patches
No full textA new motion field segmentation algorithm under the 8-parameters motion model is presented which uses a multipass iterative region-refining techinique. The iterative region-refining module consists of a seed block detection and subsequent region-refining iterations. An initial estimate of an object motion is provided in the seed black detection process. This initial estimate is iteratively updated and approaches to a reliable mapping parameter set in region-refining process. A multipass composition of the module makes it possible to detect multiple motions in a scene. Our simulation results confirm that the proposed method successfully partitions an image into independently moving objects with allowable computation time
Composite hybrid valve lifter for automotive engines
No full textThis paper describes the development of a hybrid valve lifter composed of composite and steel for use in a valve train in an automotive internal combustion engine. Emphasis in this work was placed on reducing the mass of the valve lifter in order to achieve higher fuel efficiency. Several issues regarding design and manufacture of the composite hybrid valve lifter had been investigated and addressed based on the functional requirements of the valve lifter. Prototype hybrid valve lifters were manufactured and a series of durability tests were conducted on the laboratory bench. The tests showed that hybrid valve lifter were sufficiently durable to withstand the test loads. (C) 2004 Elsevier Ltd. All rights reserved
A low-power variable length decoder for MPEG-2 based on successive decoding of short codewords
No full textThis paper presents a low-power variable length decoder exploiting the statistics of successive codewords. The decoder employs small look-up tables working as fixed caches to reduce the number of activations of a variable length code detector where considerable power is consumed. The power simulation results estimated using PowerMill show that 35% energy is reduced on the average compared to the previous low-power scheme.This work
was supported in part by theKorea Science and Engineering Foundation through
the Micro Information Communication and Remote Object-oriented Systems
Research Center (MICROS) and in part by the Integrated Circuit (IC) Design
Education Center (IDEC)
An assessment of numerical parameters influencing springback in explicit finite element analysis of sheet metal forming process
No full textSpringback is one of the key factors influencing the quality of stamped sheet metal parts in sheet metal manufacture. There have been diverse efforts to evaluate and/or decrease springback for a long time. Analytical methods have been mainly developed, at first, for analyzing parts of two-dimensional or simple three-dimensional geometry. Since it is almost impossible to apply analytical methods to fully three-dimensional parts in general, numerical methods including the finite element method (FEM) have recently been developed and applied to sheet metal parts of general shape as a result of rapid progress of computing environments. However, the results of springback simulated by FEM may vary greatly according to how numerical factors are set, for example element size, punch velocity, contact penalty constant, damping ratio, etc. Therefore, a comprehensive assessment of numerical factors influencing springback is required. In this work, numerical factors influencing springback have been evaluated quantitatively using the Taguchi method. To clarify the effect of each factor, the U-draw bending process is chosen as an evaluation problem because of its large springback. In the analysis, the explicit time integration method is used in the simulation of forming stage, whereas the implicit time integration method is applied to the springback stage in order to get the static solution readily. Numerical experimentation has been carried out under various combinations of numerical factors. From comparison of the numerical results with the experimental results, factors important for springback have been assessed. (C) 1998 Elsevier Science S.A. All rights reserved
Low-Power Hybrid Structure of Digital Matched Filters for Direct Sequence Spread Spectrum Systems
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