• Title/Summary/Keyword: experimental techniques

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An Experimental Study on the Effects of the Automotive Cooling Performance by Cooling Airflow rate (II) (냉각 공기량이 자동차 냉각성능에 미치는 영향에 관한 실험적 연구(II))

  • Kim, J.H.;Lee, H.C.;Lee, M.H.;Park, J.N.;Cha, K.O.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.940-945
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    • 2001
  • Gasoline engine manufacturers are currently considering designs that will result in low combustion air temperature for improvement of fuel consumption and emission levels. There are a variety of cooling systems that can be used to accomplish this goal. Cooling is therefore normally achieved through a balance of ram and fan action. This paper studies the various systems and compare the cooling performance for several conditions, based on a automotive engine. An experimental analysis was developed to predict the interaction of the fan system and the heat exchangers of the engine cooling system. The local temperature induced by the fan on the cooling system is measured. These experimental result were accomplished using airflow management techniques.

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Controller design with experimental approach (실험적 접근을 통한 제어기 설계)

  • 신시중;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.200-205
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    • 1992
  • The classical control theory has been developed successfully for the design of a system controller and has evolved continually. Even though sophisticated simulation techniques and software packages are available, there is still some difficulty in the design of a complex system controller at the desk. So the trial and error method is sometimes used to design a new controller, but it requires excess time and cost. This paper suggests a controller design method through the experimental approach. The basic concept is to adjust gradually the design parameters of the controller to the simulation results and experimental data of a similar real system. This method will be a very useful and easy way to design an accurate and/or optimal controller for a real plant while reducing time and giving a good solution at a reasonable cost.

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Stepwise Training for Reconstructive Microsurgery: The Journey to Becoming a Confident Microsurgeon in Singapore

  • Ramachandran, Savitha;Ong, Yee-Siang;Chin, Andrew Y.H.;Song, In-Chin;Ogden, Bryan;Tan, Bien-Keem
    • Archives of Plastic Surgery
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    • v.41 no.3
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    • pp.209-212
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    • 2014
  • Microsurgery training in Singapore began in 1980 with the opening of the Experimental Surgical Unit. Since then, the unit has continued to grow and have held microsurgical training courses biannually. The road to becoming a full-fledged reconstructive surgeon requires the mastering of both microvascular as well as flap raising techniques and requires time, patience and good training facilities. In Singapore, over the past 2 decades, we have had the opportunity to develop good training facilities and to refine our surgical education programmes in reconstructive microsurgery. In this article, we share our experience with training in reconstructive microsurgery.

A Numerical Study for the Three-Dimensional Fluid Flow Past Tube Banks and Comparison with PIV Experimental Data

  • Ha, Man-Yeong;Kim, Seung-Hyeon;Kim, Kyung-Chun;Son, Young-Chul
    • Journal of Mechanical Science and Technology
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    • v.18 no.12
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    • pp.2236-2249
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    • 2004
  • The analysis for the three-dimensional fluid flow past tube banks arranged in equilateral-triangular form at Re$\_$max/=4,000 is carried out using a large eddy simulation technique. The governing equations for the mass and momentum conservation are discretized using the finite volume method. Parallel computational techniques using MPI (Message Passing Interface) are implemented in the present computer code. The computation time decreases linearly proportional to the number of used CPUs in the present parallel computation. We obtained the time-averaged streamwise and cross-streamwise velocities and turbulent intensities. The present numerical results are compared with the PIV experimental data and agree generally well with the experimental data.

Vision-Based Haptic Interaction Method for Telemanipulation: Macro and Micro Applications (원격조작을 위한 영상정보 기반의 햅틱인터렉션 방법: 매크로 및 마이크로 시스템 응용)

  • Kim, Jung-Sik;Kim, Jung
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1594-1599
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    • 2008
  • Haptic rendering is a process that provides force feedback during interactions between a user and an object. This paper presents a haptic rendering technique for a telemanipulation system of deformable objects using image processing and physically based modeling techniques. The interaction forces between an instrument driven by a haptic device and a deformable object are inferred in real time based on a continuum mechanics model of the object, which consists of a boundary element model and ${\alpha}$ priori knowledge of the object's mechanical properties. Macro- and micro-scale experimental systems, equipped with a telemanipulation system and a commercial haptic display, were developed and tested using silicone (macro-scale) and zebrafish embryos (micro-scale). The experimental results showed the effectiveness of the algorithm in different scales: two experimental systems applied the same algorithm provided haptic feedback regardless of the system scale.

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Improved Performance of Permanent Magnet Synchronous Motor by using Particle Swarm Optimization Techniques

  • Elwer, A.S.;Wahsh, S.A.
    • Journal of Power Electronics
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    • v.9 no.2
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    • pp.207-214
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    • 2009
  • This paper presents a modem approach for speed control of a PMSM using the Particle Swarm Optimization (PSO) algorithm to optimize the parameters of the PI-Controller. The overall system simulated under various operating conditions and an experimental setup is prepared. The use of PSO as an optimization algorithm makes the drive robust, with faster dynamic response, higher accuracy and insensitive to load variation. Comparison between different controllers is achieved, using a PI controller which is tuned by two methods, firstly manually and secondly using the PSO technique. The system is tested under variable operating conditions. Implementation of the experimental setup is done. The simulation results show good dynamic response with fast recovery time and good agreement with experimental controller.

A Study on the Experimental Characteristics of Libeskind's Early Drawing Works (리베스킨트 초기 드로잉 작업의 실험적 특성에 관한 연구)

  • Chung, Tae-Yong
    • Korean Institute of Interior Design Journal
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    • v.22 no.1
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    • pp.97-104
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    • 2013
  • This study aims at finding out the characteristics and influences of Libeskind's early drawing works through comparisons of each drawing. The importance of his experimental drawing works is not only their uniqueness but also relationship to creation and development of his architecture. Libeskind's musical and educational background had great impacts on forming his early drawings. A series of drawings including 'Micromegas', 'Chamberworks', and 'Theatrum Mundi' shows variety and experiments about reconstruction of three dimensional architectural fragments, abstractive line drawing and plane oriented painting. Libeskind himself cease to experiment drawing techniques but their characteristics still remain in his sketches, diagram and conceptual drawings. In spite of influences of undergraduate design studios, theoretical background of graduate studies, their experimental features are due to his continuous endeavor to make and develop his drawing skills and contents. As a result, his early drawings act as media and way to communicate and develop his concepts.

Experimental and numerical assessment of EBF structures with shear links

  • Caprili, Silvia;Mussini, Nicola;Salvatore, Walter
    • Steel and Composite Structures
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    • v.28 no.2
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    • pp.123-138
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    • 2018
  • Eccentrically braced frames (EBF) represent an optimal structural solution for seismic prone areas, being able to provide high dissipative capacity and good elastic stiffness, to withstand strong seismic events without significant loss of bearing capacity and to avoid damage to non-structural elements in case of low and moderate earthquakes. The accurate knowledge of the cyclic behaviour of the dissipative links, characterizing the whole performance of EBFs, is required to optimize the structural properties and to refine the design techniques adopted for multi-storey buildings' analysis. Reliable numerical models for the links, at the same time requiring a limited computational effort, are then needed. The present work shows the results of a wide experimental test campaign executed on real-scale one storey/one bay frames with horizontal and vertical links, together with the elaboration of a simple semi-analytical model for the quick representation of the cyclic behaviour of shear links.

A Review of Mode Synthesis Techniques and Its Application Between FE and Experimental Model (부분 구조 합성법의 고찰 및 유한 요소 모델과 실험 모델과의 합성에 관한 연구)

  • 최재웅;이상설;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.4
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    • pp.799-806
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    • 1989
  • Component mode synthesis (CMS) method can be divided into free, fixed and hybrid interface method according to each component's connecting conditions. In this paper, major mode synthesis methods were reviewed and their accuracies were examined by comparing the calculated eigenvalues with those from full finite element (FE) model. Also, CMS is expanded into the coupling between finite element (FE) and experimental model. Since the assumed experimental data seldom have slope information, the slope information at the interface points is prepared by curve-fitting of the calculated values. A simple beam structure to show the effectiveness of the above method, and we found that it can improve the accuracy of the synthesis method in calculation, expecially in the low modes.

The uniaxial strain test - a simple method for the characterization of porous materials

  • Fiedler, T.;Ochsner, A.;Gracio, J.
    • Structural Engineering and Mechanics
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    • v.22 no.1
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    • pp.17-32
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    • 2006
  • The application of cellular materials in load-carrying and security-relevant structures requires the exact prediction of their mechanical behavior, which necessitates the development of robust simulation models and techniques based on appropriate experimental procedures. The determination of the yield surface requires experiments under multi-axial stress states because the yield behavior is sensitive to the hydrostatic stress and simple uniaxial tests aim only to determine one single point of the yield surface. Therefore, an experimental technique based on a uniaxial strain test for the description of the influence of the hydrostatic stress on the yield condition in the elastic-plastic transition zone at small strains is proposed and numerically investigated. Furthermore, this experimental technique enables the determination of a second elastic constant, e.g., Poisson's ratio.