• Title/Summary/Keyword: Similitude

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A study on characteristics of seadike settlement according to the change of tidal level (조위 변화에 따른 제체의 침하 특성에 관한 연구)

  • Yoo, Hyun-Gu;Kim, Jong-Yun;Yoon, Myung-Seok;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1029-1036
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    • 2009
  • Seapage condition by sea water may appears on sea dike due to the gap of tidal, which generated by the sealevel repeatedly moves up and down result of the change of tidal level. In this study, apparatus was developed to apply similitude after setting the critical section. It was found that the soil loss was dramatically increased by increasing hydraulic gradient step by step. Also, to understand the change of seadike which considered the changes of the change of tidal level and inside sealevel, it was executed the experiments which divided the sea level condition of inside by continually changes the sealevel difference which is outside of the high tide and ebb tide.

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Design of the Radial Extrusion Process for the General-Purpose Flange Using Model Material (모델재료를 이용한 범용 플랜지의 레이디얼 압출 공정설계)

  • Lee, Sang-Don;Byon, Sung-Kwang
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.17 no.2
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    • pp.114-120
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    • 2008
  • This study is to compare and analyze the material flow, deformation characteristics, and forming load of flange by means of similitude experimental method of model material using plasticine. In order to find optimal forming conditions, prototype experiments were designed to investigate forming characteristics of general-purpose flange under various working conditions. As a result of prototype experiments, billet thickness and gap-height ratio was found to be the most influential experimental parameter in flange forming. Forming loads from prototype experiments were compared to the results of finite element analysis after conducting estimation of forming loads of real material. Results of prototype experiments based on model material techniques are expected to be used as a basic data of die design f3r the development of products and process.

A Study on Load Transfer Efficiency of Skewed Transverse Joint of Concrete Pavement by the Fatigue Test (피로실험에 의한 콘크리트 포장체 경사가로줄눈부의 하중전달율에 관한 연구)

  • Hwang, Seung-Eui;Bae, Ju-Seong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.5 no.3
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    • pp.203-211
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    • 2001
  • This paper presents load transfer efficiency of skewed transverse joint of jointed concrete pavement with the fatigue model test. A 1/12 scale model was used to satisfy the geometry, loading, material similitude, which are variables to the skew angel of transverse joint. As the test results by fatigue load 700kgf applied, the deflection and stress of transverse joint were decreased as to increasing of skew angle of transverse joint. In addition, load transfer efficiency of transverse joint with skew angle is better than the load transfer efficiency of transverse joint without skew angle.

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Railway Boom and the Emergence of Mechanical Engineers in England ("철도붐"과 영국 기계 엔지니어의 사회적 등장)

  • Lee, Eun-Kyoung
    • Journal of Engineering Education Research
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    • v.14 no.5
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    • pp.46-52
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    • 2011
  • This paper examines the emergence of mechanical engineers in the technological and social context of professionalization in England. Despite their technological progress, most steam engine wrights and machine tool builders were individual workshop owners working to order in the early 19th century. In the 1830s and 1840s, however, the railway boom produced so called railway engineers by providing them with some managerial experience as the canal building did in civil engineering. Railway engineers played a dominant role to establish the Institute of Mechanical Engineers(IME) in 1848. It was IME that stated what is a mechanical engineer and helped its members be in the similitude of the civil engineers in social and technological activities.

DOMAIN BLOCK ESTIMATING FUNCTION FOR FRACTAL IMAGE CODING

  • Kousuke-Imamura;Yuuji-Tanaka;Hideo-Kuroda
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1999.06a
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    • pp.57.2-62
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    • 1999
  • Fractal coding is image compression techniques using one of image characteristics self-transformability. In fractal image coding, the encoding process is to select the domain block similar to a range block. The reconstructed image quality of fractal image coding depends on similitude between a range block and the selected domain block. Domain block similar to a range blocks. In fact, the error of the reconstructed image adds up the generated error in encoding process and the generated error in decoding process. But current domain block estimating function considered only the encoding error. We propose a domain block estimating function to consider not only the encoding error but also the decoding error. By computer simulation, it was verified to obtain the high quality reconstructed image.

The Prediction of Littoral Transport in the Vicinity of Coastal Structures (해안구조물 주위의 표사이동예측)

  • 김규한;이봉희
    • Water for future
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    • v.20 no.1
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    • pp.63-72
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    • 1987
  • This study describes a procedure of movable bed model tests and discusses the similitude with a view to state of the art. The prediction of littoral transport in the vicinity of coastal structure of nuclear power #9, 10 has been attempted. From the result of the present movable model study, it was found that the offshore breakwater is more excellent than the groyne and the rip-current barrier for the prevention against in take siltations and for the stability of investigated coastal structure of nuclear power plant.

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Experimental Study on the Seismic Response of High-Rise RC Bearing-Wall Structures with Irregularity (고층 RC 벽식 비정정 구조물의 지진거동에 관한 실험적 연구)

  • 이한선;고동우
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.03a
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    • pp.321-328
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    • 2003
  • The objective of this study is to investigate the seismic response of high-rise RC bearing-wall structures with irregularity. For this purpose, three 1:12 scale 17-story reinforced concrete model structures were constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2-story frames have three different layouts of the plan : The first one is a moment-resisting frame system, the second has a infilled shear wall with symmetric plan and the third has a infilled shear wall with eccentricity, Then, these models were subjected to a series of earthquake excitations. The test results show the followings: 1) the existence of shear wall reduced greatly shear deformation at the piloti frame, but has almost the negligible effect on the reduction of the overturning-moment angle, 2) the frame with shear wall resists most of overturning moment in severe earthquake, 3) the torsional behavior is almost independent of the translational, 4) the absorbed energy due to the overturning deformation has the largest portion in the total absorbed energy.

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Shaking Table Test for Seismic Performance Evaluation of Non-Seismic Designed Wall-Type Apartment (내진설계 되지 않은 공동주택의 진동대 실험에 의한 내진성능 평가)

  • Chung, Lan;Lee, Joung-Woo;Park, Tae-Won
    • Journal of the Korea Concrete Institute
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    • v.18 no.6 s.96
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    • pp.721-728
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    • 2006
  • Earthquakes are reported thai building structures have been colossal damaged, but before 1988 designed structures which were not applicate seismic design code have no seismic performance. Especially, for the apartment structures were indicated that it have no resist wall element of earthquake before 1988 designed structures. We have to evaluate for seismic performance this structures, therefore it will be retrofitted for seismic index sufficient structures. We performed seismic performance evaluation for model structures by MIDAS which is general structure analysis software. In this study, it was performed shaking table test to evaluate model structure which is reinforcement concrete and 5 floors for seismic performance index. We made specimens by similar's law and tested shaking table test. In the shaking table test it is not performed prototype model test because of space and equipment condition. So we had made scale-down model for 1/5 by similar's law. That's why it needs for the evaluation of performance. However, it is not possible to do an experiment of prototype owing to the shortage of space and the limit of an experimental instrument in the shaking table test. Then, modeling and reducing the part of prototype do the experiment. In this experiment a shaking table test is done and seismic performance of model structures is evaluated by using similitude laws for scale down specimen. As a result it is proved that non-seismic design structures need to retrofit since seismic performance shows life safe grade in 0.12g of an earthquake.

Evaluation of Performance of the Teflon-Type Seismic Foundation Isolation System (테프론형 기초지진격리장치의 성능평가)

  • Son, Su Won;Kim, Eung Soo;Na, Geon Ha;Kim, Jin Man
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.3
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    • pp.125-135
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    • 2017
  • Various seismic isolation methods are being applied to bridges and buildings to improve their seismic performance. Most seismic isolation systems are the structural seismic isolation systems. In this study, the seismic performance of geotechnical seismic isolation system capable of isolating the lower foundation of the bridge structure from ground was evaluated. The geotechnical seismic isolation system was built with teflon, and the model structure was made by adopting the similitude law. The response acceleration for sinusoidal waves of various amplitudes and frequencies and seismic waves were analyzed by performing 1-G shaking table experiments. Fixed foundation, Sliding foundation, and Rocking foundation were evaluated. The results of this study indicated that the Teflon-type seismic foundation isolation system is effective in reducing the acceleration transmitted to the superstructure subject to large input ground motion. Response spectrum of the Rocking and Sliding foundation structures moves to the long period, while that of Fixed foundation moves to short period.

Effect of design factors on the performance of heat exchanger with a slit fin (슬릿휜형 열교환기의 성능에 대한 설계인자의 영향)

  • Yun, J.Y.;Lee, K.S.;Kim, H.Y.;Kang, H.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.210-220
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    • 1997
  • This study is to systematically analyze the effect of various kinds of design parameters on heat transfer and pressure drop characteristics of heat exchanger with a slit fin. TAGUCHI method, known to us as a very reasonable tool in the parametric study, is employed in the present work. Experimental factors have been limited to seven cases, considering the production of sample and the cost. The 18 kinds of large scale models are made by compounding level on each factor and the heat transfer and flow characteristics on each model has been analyzed. The present results allow us to be able to quantitatively estimate the various parameters affecting the heat exchanger performance, and main factors for an optimum design of a heat exchanger have been selected. The optimum design value on each parameter was presented and the reproducibility on the results was guaranteed.

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