• Title/Summary/Keyword: 정역학

Search Result 44, Processing Time 0.041 seconds

Application of MS Excel in Teaching Statics (엑셀 프로그램을 활용한 정역학 교육 사례)

  • Kim, Youngheub
    • Transactions of the KSME C: Technology and Education
    • /
    • v.2 no.1
    • /
    • pp.21-28
    • /
    • 2014
  • As one of the most famous spreadsheet programs that is widely applied to a variety of fields in business, MS Excel has also been used for educational purposes due to its feature of wide accessibility, enabling students to use the program through almost any kind of PC that now exists. The program is mainly used for numerical analysis and formulae applications in the fields of science and engineering. This paper shall provide the key to understanding the application of MS Excel to teaching Statics through the illustration of its essential functions for education. Also, the development process of the analysis program using macros and VBA(Visual Basic for Applications) is described for the deeper comprehension of advanced applications. Students were not only able to solve the Statics problems using basic features of MS Excel, but also discovered new systematic methods of approaching complex problems and developed application programs using macros and VBA.

Investigation of ultraprecision machining characteristics by molecular statics simulation method (분자정역학 기법을 이용한 초미세 절삭특성에 관한 고찰)

  • 정구현;이성창;김대은
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.14 no.3
    • /
    • pp.122-129
    • /
    • 1997
  • Machining technology has emerged to the point of performing atomic-scale fabrication. In tail paper atomic-scale machining characteristics are investigated by using Molecular Statics simulation method. The cutting model used in this work simulates machining with tools such as an AFM. It is shown that built-up edge formation and cutting forces depend on tool tip geometry. Also, the material flow during cutting is shown for various cutting conditions such as depth of cut, rake angle, and edge radius of tool.

  • PDF

Vehicle Dynamics Modeling and Correlation Using the Kinematic and Compliance Test of the Suspension (현가장치 기구정역학 시험에 의한 차량동역학 모델링 및 시험검증)

  • Kim Sangsup;Jung Hongkyu
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.13 no.1
    • /
    • pp.109-118
    • /
    • 2005
  • A functional suspension model is proposed as a kinematic describing function of the suspension that represents the relative wheel displacement in polynomial form in terms of the vertical displacement of the wheel center and steering rack displacement. The relative velocity and acceleration of the wheel is represented in terms of first and second derivatives of the kinematic describing function. The system equations of motion for the full vehicle dynamic model are systematically derived by using velocity transformation method of multi-body dynamics. The comparison of field test results and simulation results of the ADAMS/Car demonstrates the validity of the proposed functional suspension modeling method. This model is suitable for real-time vehicle dynamics analysis.

동력학에 대한 교과과정

  • 염영일
    • Journal of the KSME
    • /
    • v.28 no.2
    • /
    • pp.150-155
    • /
    • 1988
  • 공학의 기본을 이루고 있는 Newton의 역할은 고체역학과 유체역학으로 분류가 되며 고체역학은 다시 정역학과 동역학으로 세분된다. 동역학은 가속의 운동을 가진 물체를 다루는 학문으로 다시 두 부분으로 나누어진다. 하나는 운동학(kinematics)이고 다른 하나는 운동역학(kinetics) 이다. 운동학은 운동자체 즉 속도, 가속도만을 취급하며 운동역학은 운동을 일으키는 힘과 그 결과로 생기는 운동을 연관짓는 학문이다.

  • PDF

Effects of Air Compressibility on the Hydrodynamic Forces of a Bag (백의 유체역학적 힘과 공기의 압축성 효과)

  • G.J. Lee
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.30 no.3
    • /
    • pp.51-61
    • /
    • 1993
  • The hydrodynamic problem when the pressurized bag submerges partially into water and oscillates was formulated by Lee(1992), and the solution method was given. In his formulation, however, the compressibility of air was neglected and the pressure inside the bag was assumed to be constant. In this paper, the formulation was done including the air compressibility and the wall to block fling around phenomenon. The compression process was assumed to be a isothermal process for a static problem, isentropic process for a dynamic problem. And the stability was analyzed for the static problem. Through the various numerical calculations, the forces and the shape of the bag were compared with those of a rigid body case, constant pressure case, and variable pressure case.

  • PDF

Face Detection And Recognition using Hidden Markov Models (HMM 을 이용한 얼굴 검출과 인식)

  • 박호석;차영석;최현수;배철수;권오홍;최철재;나상동
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2000.05a
    • /
    • pp.336-341
    • /
    • 2000
  • Hidden Markov Model(HMM)을 기반으로 한 얼굴 검출과 얼굴 인식에 대한 프레임작업에 대한 것이다. 관찰 벡터는 Karhunen-Loves Transform(KLT)의 상관관계를 이용하여 얻은 HMM의 정역학 특성을 사용하였으며, 본 연구에서 보여준 얼굴인식 방법은 이전의 HMM 기반의 얼굴인식 방법에서 인식률을 약간 개선함으로써 컴퓨터 연산을 훨씬 간단히 할 수 있음을 보여준다

  • PDF

Effect for Electrowetting of Droplet according to Applied Voltage and Height of Electrode (전극의 전압과 위치변화가 액적의 Electrowetting에 미치는 영향)

  • Sung, Tan-Il;Cho, Young-Han;Kim, Young-Sun;Choi, Hong-Soon;Park, Il-Han
    • Proceedings of the KIEE Conference
    • /
    • 2008.07a
    • /
    • pp.800-801
    • /
    • 2008
  • 유체의 전자기력에 의한 거동특성 파악을 위해 전자기 체적력에 의한 접근법을 이용하였다. 수정된 Kelvin force을 유체정역학 방정식에 도입하고 유체표면에서의 압력이 일정해야한다는 원리를 이용하여 유체 표면의 형상을 얻어낸다. 액적에 인가하는 전압의 크기와 전극을 꽂는 높이의 변화에 따른 액적의 Electrowetting 영향을 수치해석한다.

  • PDF

Kinematics and Inverse Kinematics in Unmanned Bicycle System (무인자전거 시스템의 정역학 및 역정역학)

  • Ham, Woon-Chul
    • The Journal of Korea Robotics Society
    • /
    • v.1 no.1
    • /
    • pp.73-80
    • /
    • 2006
  • Bicycle is one of convenient transportation system. In this paper, we derive a more precise kinematics of bicycle system compared with other ones which were suggested by other researchers. In the derivation of kinematics we adopted a physical concept called virtual wheel. We also propose an algorithm for deriving inverse kinematics of a bicycle system. In this paper, the meaning of inverse kinematics is to find the time functions of steering angle and driving wheel speed for a given desired path trajectory. From the computer simulation, we show the validity of our proposed algorithm for inverse kinematics of bicycle system.

  • PDF

Effects of Internal Waves on Dynamics of Hypoxic Waters in Lake Biwa (일본 비와호의 빈산소 수체 거동에 미치는 내부파의 영향)

  • Kitazawa, Daisuke;Kumagai, Michio;Hasegawa, Naoko
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.13 no.1
    • /
    • pp.30-42
    • /
    • 2010
  • The effects of internal waves on dynamics of hypoxic waters were investigated by numerical simulation by means of a hydrostatic-ecosystem coupled numerical model for Lake Biwa. The numerical model consists of hydrostatic and ecosystem submodels. Numerical simulation was carried out for a period during April 2007 and March 2008, after preliminary numerical simulation for three years. As a result, the numerical model could capture the vertical profiles of the observed water quality. During September 30 and October 21 in 2007, the major internal waves were Kelvin and Poincare waves, the periods of which were 1.63 or 1.77 days and 0.48 days, respectively. Hypoxic waters appeared in bottom boundary layer around October and were still when thermocline locates in upper layer. During late autumn and winter seasons, differences in density between upper and lower layers were reduced and the amplitude of internal waves increased. Hypoxic waters began to move under the effects of internal waves. Movement of hypoxic waters will diminish the habitat for aquatic organisms in deeper waters.

Design of a Mechanism to Increase Lateral Stability of Mobile Robot (이동로봇의 횡방향 안정성 증대를 위한 기구)

  • 정상국;최용제
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2004.10a
    • /
    • pp.1148-1153
    • /
    • 2004
  • This paper presents the mechanism to increase lateral stability of a mobile robot using an energy stability margin theory. Previous measure of stability used in a wheeled mobile robot has been based on a static stability margin. However, the static stability margin is independent of the height of the robot and does not provide sufficient measure for the amount of stability when the terrain is not a horizontal plane. In this work, the energy stability margin theory, which is dependent on robot's height is used to develop a 2 dof mechanism to increase lateral stability. This proposed mechanism shifts the center of gravity of the robot to the point where the energy stability margin is maximized and overall stability of the robot equipped with this mechanism will be increased.

  • PDF