• 한국자동차공학회논문집
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• 제13권4호
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• pp.105-112
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• 2005

Analyses of dynamic models which were one and two degrees of freedom, and had the nonlinear springs and dampings with certain polynomial functions were performed from SIMULINK in MATLAB. Those consisted of 12 programs and were built on the basis of the preceding programs fur the linear dynamic simulations. However the programs for the nonlinear simulations were quite different from those f3r the linear ones, and showed the results of the analyses in real time with animating. It was found that the programs would help us to solve any kind of nonlinear dynamic simulation with one and two degrees of freedom. Especially, the simulations for 1 DOF system with cubic nonlinear spring farce showed the results for Duffing's equation, of which phenomena were jump-up and jump-down. It will be applied to the dynamic simulation of the car seat vibration with a passenger, of which model has the equivalent nonlinear springs and is two degrees of freedom.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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• pp.89-92
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• 1996

This paper describes a detailed simulation model of the static condenser (STATCON) to analyze the dynamic interaction with the ac transmission line. The static condenser was represented by a 12-pulse voltage-source inverter sharing an energy storage dc capacitor. The voltage-source inverter consists of two 6-pulse bridges modeled with ideal gate-turn-off switches. The control system for the static condenser was designed through a mathematical model deduced from the equivalent circuit. Simulation results show that the conceived model is very effective to analyze the dynamic interaction between the static condenser and the ac transmission system.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권3호
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• pp.318-328
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• 2018

Disk type underwater gliders are a new type of underwater gliders and they could glide in various directions by adjusting the internal structures, making a turnaround like conventional gliders unnecessary. This characteristic of disk type underwater gliders makes them have great potential application in virtual mooring. Considering dynamic models of conventional underwater gliders could not adequately satisfy the motion characteristic of disk type underwater gliders, a nonlinear dynamic model for the motion simulation of disk type underwater glider is developed in this paper. In the model, the effect of internal masses movement is taken into consideration and a viscous hydrodynamic calculation method satisfying the motion characteristic of disk type underwater gliders is proposed. Through simulating typical motions of a disk type underwater glider, the feasibility of the dynamic model is validated and the disk type underwater glider shows good maneuverability.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.255-262
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• 2018

Purpose: To obtain the dynamic characteristics (spring stiffness and damping coefficient) of a rubber mount supporting a tractor cabin in order to develop a simulation model of an agricultural tractor. Methods: The KS M 6604 rubber mount test method was used to test the dynamic characteristics of the rubber mount. Of the methods proposed in the standard, the resonance method was used. To perform the test according to the standard, a base excitation test device was constructed and the accelerations were measured. Results: Displacement transmissibility was measured by varying the frequency from 3-30 Hz. The vibration transmissibility at resonance was confirmed, and the dynamic stiffness and damping coefficient of the rubber mount were obtained. The front rubber mount has a spring constant of 1247 N/mm and damping ratio of 3.27 Ns/mm, and the rear rubber mount has a spring constant of 702 N/mm and damping ratio of 1.92 Ns/mm. Conclusions: The parameters in the z-direction were obtained in this study. In future studies, we will develop a more complete tractor simulation model if the parameters for the x- and y-directions can be obtained.

• 설비공학논문집
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• 제13권11호
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• pp.1079-1088
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• 2001

A dynamic simulation model was developed to analyse the transient characteristics of a multi-inverter heat pump. The programs included a basic air conditioning system such as a evaporator, condenser, compressor, linear electronic expansion valve (LEV) and by-pass circuit. The theoretical model was derived from mass conservation and energy conservation equations to predict the performance of the multi-inverter heat pump at various operating conditions. Calculated results were compared with the values obtained from the experiments at different operation frequencies of compressor, area of the LEV and configuration of indoor units operation. The results of the simulation model showed a good agreement with the experimental ones, so that the model could be used as an efficient tool for thermodynamic design and control factor design of air-conditioners.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1255-1263
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• 2004

An a priori test has been conducted for the dynamic mixed model which was generalized for the prediction of passive scalar field in a turbulent channel flow The results from a priori tests indicated that dynamic mixed model is capable of predicting both subgrid-scale heat flux and dissipation rather accurately. The success is attributed to the explicitly calculated resolved term incorporated into the model. The actual test of the model in a LES a posteriori showed that dynamic mixed model is superior to the widely used dynamic Smagorinsky model in the prediction of temperature statistics.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2585-2593
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• 2011

Maglev train system has been continuously received attention as it provides good ride quality and low noise and vibration level. Furthermore it is an eco-friendly transport system with little dust pollutant. However the dynamic performance of the vehicle has been influenced by the track layout and the structural stability of guideways and girders, etc. Especially the levitation control of magnetic module is the most important performance of the Maglev system and is very sensitive about the control algorithm and the parameters of the controller. In this paper, the co-simulation of the control and dynamic model has been proposed and the simulation results for the running simulation on the curve track has been shown.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.101-109
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• 1997

A tool for the dynamic simulation and design technique of the excavator plays an important role in the prediction of dynamic behavior of the excavator in the initial design stage. In this paper, a flexible multibody dynamic analysis model including track of the crawler type excavator is developed using DADS and ANSYS. Through the driving simulation of the excavator travelling over rough road track, frequency characteristics of the upper frame and cabin are obtained, and the reaction forces acting on the track rollers are also presented for the fatigue life estimation. The effect of boom vibration modes on the joint reaction forces and accelerations is presented from the swing simulation.

• 대한전기학회논문지:전력기술부문A
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• 제49권12호
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• pp.581-588
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• 2000

This paper presents the power system application of a PWM base UPFC through EMTP simulation. A PWM base UPFC model is constructed and detailed switching-level simulation is performed using EMTP. The dynamic responses of UPFC are analyzed. Based on the simulation results, the appropriate equivalent impedances of UPFC voltage-source model which represent similar dynamics with PWM based UPFC are determined by optimization routine. This paper also analyzes the influence of the power system strength on the dynamic responses of UPFC. Finally this paper shows that the performance of UPFC is improved by control parameter tuning when UPFC is installed to weak power system.

• 대한기계학회논문집A
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• 제38권11호
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• pp.1201-1206
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• 2014

본 논문에서는 가상의 V상차 작업을 위한 이벤트 기반의 휠로더 운전자 모델을 개발하였다. 운전자 모델 개발의 목적은 휠로더의 일반적인 작업인 V상차 작업 시 동역학적 해석과 작업성능을 가상의 시뮬레이션 모델과 운전자 입력을 이용해 예측 및 평가하는 것이다. V상차 작업은 4단계로 이루어져 있으며, 총 8 개의 이벤트로 인해 순차적으로 작업이 진행된다. 개발된 3D 휠로더 시뮬레이션 모델은 Matlab/Simulink 환경에서 구성 되었으며, 시뮬레이션 결과는 V상차 작업의 실차 데이터와 비교 되었다. 본 연구에서 개발된 운전자 모델로 향후 가상의 V상차 작업에 대한 작업성능 및 동역학적 해석이 가능할 것으로 본다.