• Title/Summary/Keyword: 운동이론

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A study on the electronic model of cochlear basilar membrane motion (기저막 운동의 전기적 모델링에 관한 연구)

  • 이윤선
    • The Journal of the Acoustical Society of Korea
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    • v.4 no.3
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    • pp.8-15
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    • 1985
  • 본 논문에서는 코클리어 기저막 운동에 관한 전기적 모델링을 래더회로를 이용하여 구현하였다. Budak 의 이론에 근거한 이득이 1보다 큰 RC 수동회로를 이용하여 귀에서의 Place Principle을 만족시 키는 특성을 갖는 모델을 제시하였으며 이는 간단한 회로를 첨가시킬시에 이득이 1보다 큰 주파수를 검 지해낼 수도 있다. 컴퓨터 Simulation을 이용한 전달함수 분석에서는 특이한 형태 의 전압전달함수를 얻 을 수 있었으며, 연구결과, 본 모델은 코클리어 기저막운동을 표현하기에 적합하다는 결론을 얻을 수 있 었다. 본 모델은 임상의학이나 그 외의 공학분야등에 이용이 가능하리라고 본다.

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Analysis of Wave Velocity for Temperature Propagation in a Mechanical Face Seal (기계평면 시일에서 온도전파를 위한 파속도의 이론적해석)

  • 김청균
    • Tribology and Lubricants
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    • v.3 no.2
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    • pp.64-67
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    • 1987
  • 미끄럼 운동에 의하여 미세한 시일링 간극에 열이 발생할 때 어떠한 빠르기로 발생된 열이 재질 내부로 전파되는가를 속도의 개념으로 이론적 해석을 하였다. 발생된 마찰열이 시일재질 내부로 전파되는 속도는 불안정한 온도의 파장에 의하여 커다란 영향을 받고 있다.

Computation of the Linear and Nonlinear Hydrodynamic Forces on Slender Ships with Zero Speed in Waves : Infinite-Depth Case (정지 세장선의 파랑 중 선형 및 비선형 유체력 계산 : 무한 수심의 경우)

  • Yong-Hwan Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.37 no.2
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    • pp.1-13
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    • 2000
  • In the present paper, an infinite-depth unified theory is applied to the computation of the linear and second-order hydrodynamic forces on slender bodies. No forward speed is assumed, which is valid for some types of ships, like FPSOs and shuttle tankers. Strip theory solution, which is essential for the extension to theory is extended to unified theory, was obtained using NIIRD program developed at MIT. The linear theory is extended to the computation of the second-order mean-drift forces and moment. Furthermore, Aranha's formular is applied to the prediction of wave drift damping coefficients. From this study, it is proved that unified theory provides an accuracy comparable with 3D panel method for the second-order forces as well as the linear solution with much less computational effort.

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Impact Force Applied on the Spent Nuclear Fuel Disposal Canister that Accidentally Drops and Collides onto the Ground (사고로 지면에 추락낙하 충돌하는 고준위폐기물 처분용기에 발생하는 충격력)

  • Kwon, Young Joo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.5
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    • pp.469-481
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    • 2016
  • In this paper, a mathematical methodology was theoretically studied to obtain the impact force caused by the collision between rigid bodies. This theoretical methodology was applied to compute the impact force applied on the spent nuclear fuel disposal canister that accidentally drops and collides onto the ground. From this study, the impact force required to ensure a structurally safe canister design was theoretically formulated. The main content of the theoretical study concerns the rigid body kinematics and equation of motion during collision between two rigid bodies. On the basis of this study, a general impact theory to compute the impact force caused by the collision between two bodies was developed. This general impact theory was applied to theoretically formulate the approximate mathematical solution of the impact force that affects the spent nuclear fuel disposal canister that accidentally falls to the ground. Simultaneously, a numerical analysis was performed using the computer code to compute the numerical solution of the impact force, and the numerical result was compared with the approximate mathematical solution.

Shape and Motion Visualization of the Left Ventricle using a Dynamic Gaussian Blob Model (동적 가우시안 블럽 모델을 이용한 좌심실의 형태 및 운동 가시화)

  • Choi, Soo-Mi;Kim, Myoung-Hee
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.9
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    • pp.768-776
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    • 2000
  • 본 논문에서는 심혈관 조영영상으로부터 좌심실의 형태 및 운동을 가시화하기 위해 기하학적 정보와 물리적 정보를 통합한 동적 가우시안 블럽(dynamic gaussian blob)모델을 개발하였다. 동적 가우시안 블럽 모델은 superellipsoid에 3차원 가우시안 형태함수를 갖는 단일 유한요소를 통합한 것으로, 좌심실에 작용되는 가상적인 힘에 의해 형태를 적하하고, 심박동 전 주기에서의 운동을 추적한다. 또한 벽 운동 정도에 따라 다른 색을 지정하여 볼 수 있도록 함으로써 벽 운동에 이상이 있는 부위를 육안으로 쉽게 판별할 수 있도록 하였다. 이와 같은 좌심실의 동적.색체 가시화는 형태가 변황되는 심장질환이나 허혈이나 심근경색증처럼 심실벽 운동에 이상이 있는 질환의 진단을 도울 수 있다.

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Development of RecurDyn Module for Wind Turbine Analysis Applying BEM Theory (BEM 이론을 적용한 풍력발전기 해석용 RecurDyn 모듈 개발)

  • Lim, Dae Guen;Yoo, Wan Suk
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.2
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    • pp.115-120
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    • 2014
  • In this study, a module is developed for modeling and analyzing dynamic behavior of a wind turbine using RecurDyn, which is a commercial multi-body dynamics software developed by FunctionBay, Inc. The wind turbine consists of tower, nacelle, hub and blades. Tower and blades are regarded as flexible bodies for considering elastic effect using beam theory and spring force. In this paper, a constant speed wind was assumed and aerodynamic force is modeled using BEM theory. Dynamic analysis applying this aerodynamic force is carried out. To verify the validity of analysis results, these results are compared to those of GH-Bladed which is a commercial software for analyzing wind turbine system distributed by Garrad Hassan.

Prediction of Hydodynamic Impact Loads on Three-Dimensional Bodies (3차원 물체에 작용하는 유체동력학적 충격하중추정)

  • Troesch, Arimin W.;Kang, Chang-Gu
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.3
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    • pp.73-88
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    • 1990
  • The three dimensional aspects of hydrodynamic impact are discussed. Theoretical and experimental results for a sphere and a cusped body are presented. The cusped body is axisymmetric and resembles the bow profile of a ship with flare. The sphere was subjected to both vertical and oblique impact angles while the cusped body experienced only vertical motion. Three dimensional calculations using normal dipole distributions and an equi-potentioal free surface are compared with experimental results. The theoretical boundary value problem was solved using a known interior flow. This procedure reduced computation times significantly. Comparisons between theory and experiment show that, depending upon the body shape theoretical estimates of the maximum impact force may be larger or smaller than the experimental values. But the theoretical estimate can be used for practical purposes.

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A Constitutive Equation with Impulse-Momentum Theory for the Expanded Polypropylene (충격량-운동량 이론을 접목시킨 발포 폴리프로필렌의 구성방정식)

  • Kim, Byeong Kil;Cho, Jae Ung;Jeong, Kwang Young;Kim, Nam Hoon;Oh, Bum S.;Hahn, Youngwon;Cheon, Seong S.
    • Composites Research
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    • v.29 no.3
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    • pp.91-97
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    • 2016
  • In this paper, impulse-momentum theory was coupled to a constitutive equation both for implementing quasi-static and impact characteristics of EPP (Expanded polypropylene). Also, parameters which have physical meanings were expressed as functions of relative density. Simultaneous nonlinear Newton-Raphson method was applied to find the proper values for parameters in the constitutive equation along with quasi-static test data. Results from the impulse-momentum theory coupled constitutive equation showed good agreement with experimental data and the potential to be applied to different material type polymeric foam.

The Ways of Savoring for Promoting Exercise Participation in Middle-aged Women: Focused on Savoring theory in Positive Psychology (중년여성의 운동참여 촉진을 위한 향유방식: 긍정심리학의 향유 이론을 중심으로)

  • Kwon, Oh-Jung
    • 한국체육학회지인문사회과학편
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    • v.58 no.3
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    • pp.123-141
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    • 2019
  • The purpose of this study is to explore the ways of savoring of physical activities in middle-aged women based on the savoring theory of positive psychology. The first step was to understand the background of exercise participation experience and to provide basic information about savoring method. In the second stage, we used the open questionnaire to collect the savoring methods used during the exercise, and then, in-depth interviews were used to specify the savoring method. Open questionnaires were categorized according to the similarity of content and then nominated based on the savoring method. In-depth interviews were conducted to explore the cases of each method in detail. As a result, middle-aged women were found to use the savoring methods such as sharing with others, celebrating, comparing, feeling fine, blessing, expressing with behavior in physical activity. Through in-depth interviews, each case of savoring was embodied based on the savoring theory of positive psychology. Based on the results of the study, the possibility of applying the savoring method in the field of exercise instruction of middle-aged women and possibility of developing the savoring related program were discussed.