• 정보과학회 컴퓨팅의 실제 논문지
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• 제20권10호
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• pp.534-542
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• 2014

멀티스케일 모델링은 시공간적으로 서로 다른 규모의 시스템을 다룰 수 있는 시뮬레이션 기법이다. 본 연구에서는 멀티스케일 모델링 연구의 일환으로 서로 다른 시뮬레이션 기법인 분자동역학과 확률회전동역학을 결합할 수 있는 방법을 제안한다. 분자동역학 프로그램 중 잘 알려진 오픈 소스인 LAMMPS를 기반으로 멀티스케일링 모델링을 구현하였으며 LAMMPS에서 정의한 제3자를 위한 표준 확장 방법을 따랐다. 제안된 방법에서는 확률회전동역학 모델을 기본으로 경계 영역은 분자동역학으로 해석 가능하게 하였고 심리스한 해석을 보장하기 위하여 중첩 영역과 정보 교환 영역을 함께 구현하였다. 예비실험을 수행한 결과, 제안된 멀티스케일 방법론이 기존 분자동역학 시뮬레이션 결과와 일치된 해석 결과를 보여주었으며 실행 시간 또한 단축시킬 수 있음을 확인하였다.

• 한국시스템다이내믹스연구
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• 제8권1호
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• pp.173-186
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• 2007

This research consists of (1) building (or molding) the Dynamics Simulation Model on Return Policy mainly used in publications, phonographs, and computer industry; which are seen used in supply chain contract known as effective control mechanism under the varied supply chain situations, and (2) analyzing the effects that return rates and seller's contract parameters have in the outcome of the model and (3) observing how the effectiveness of Return Policy changes under such circumstances where the buyer's sales ability and the seller's risk inclination are taken into account. Thus, the main purpose of this research lies in analyzing what exactly are the effects (and or outcome) that sales ability and risk inclination have in Return Policy, and additionally by conducting comprehensive research on Supply Chain Policy Dynamics Simulation Model, we will try to prove that not only the Systems Dynamics approach is highly contributive in supply chain management but also that it will serve as a foothold in future research. As a result of the research, supply chain achievement level turned out to be high when Return Policy is enforced, and the achievement level was even higher when seller's sales ability was taken into consideration along with the Return Policy. On the other hand, the achievement level decreased when the seller had risk aversive tendencies.

• 한국정밀공학회지
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• 제31권12호
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• pp.1147-1154
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• 2014

Generally, motor controller design is based on its motor dynamics. Therefore, it requires precise information of its motor dynamics. However, most of the low cost DC motors, which are widely used in industries and academia, are provided without such precise information. Even if it is given, the information is mostly imprecise. Following circumstances require one to calculate the motor dynamics information for oneself. This paper presents a simple method to readily apprehend the DC motor dynamics. First, how to establish the model of DC motor dynamics along with the model parameter identification is presented. Then, the parameter values are finetuned until the simulation response based on the dynamics model is close to the experimental response of the motor. Finally, the controller is designed with the established dynamics model. The validity of the designed controller is confirmed by the comparison of the experiment and simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.79-83
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• 1989

In this paper an engine system model is developed to characterize abd dynamic interactions among various process of engine components in the system utillizing computer simulation. simulation of the dynamics or the entire engine process and emission, including alf-fuel inlet element, intake manifold, combustion unit is carried out.

• 한국기계연구소 소보
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• 통권18호
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• pp.87-97
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• 1988

The algorithm for relation of contact status, track shift, and contact force caused from wheel/rail contact geometry is presented. Grafting this algorithm into a algorithm of general program analyzing mechanical system, the program for time domain simulation of railway vehicle dynamics, called CASOTD, was developed. In addition, as applied example of CASOTD, the dynamic simulation of railway vehicle running on a rail joint and a irregularly alinemented rail is done in this paper.

• 반도체디스플레이기술학회지
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• 제3권3호
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• pp.27-29
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• 2004

The responses of hypothetical silicon nanotubes under torsion have been investigated using an atomistic simulation based on the Tersoff potential. A torque, proportional to the deformation within Hooke's law, resulted in the ribbon-like flattened shapes and eventually led to a breaking of hypothetical silicon nanotubes. Each shape change of hypothetical silicon nanotubes corresponded to an abrupt energy change and a singularity in the strain energy curve as a function of the external tangential force, torque, or twisted angle. The dynamics of silicon nanotubes under torsion can be modelled in the continuum elasticity theory.

• 한국결정성장학회지
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• 제15권4호
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• pp.168-174
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• 2005

건조공정 중인 다공성 물질의 물성은 재료의 비균질성 즉 전위, 입자, 입계, 균열, 기공과 같은 미시적인 결함 인자들의 영향을 받는다. 따라서 다공성 물질의 건조공정을 전산 시뮬레이션하기 위해서는 연속체 스케일과 원자 스케일해석 그리고 스케일별 해석 한계 극복이 요구된다. 본 연구에서는 분자동역학 시뮬레이션으로 계산한 나노스케일 물성를 연속체 스케일 해석에 연계하는 계층적 멀티스케일 시스템을 구축하고, 다공성 세라믹 애자의 건조공정을 전산 시뮬레이션 하였다. 해석 결과, 온도, 습도, 변형률 그리고 응력 분포를 기존의 결과들과 비교하여 검증하였다.

• 한국시스템다이내믹스연구
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• 제14권3호
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• pp.135-163
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• 2013

This study aims to analyze the feedback loops and policy simulation of price fluctuation of Korean Cattle. The Korean Cattle market shows the 'Cycle of Beef' since 1970. In general, the market for agricultural commodities exhibit repeated cycles of prices and production. Why Beef products market in Korea shows the fluctuation of cattle and beef price repeatedly for forty years? To find an answer, this paper explores the feedback structure of the dynamics of the beef market by the systems thinking and build a stock-flow diagram model for the simulation of future behavior of the market sector of the Cattle. The dynamic simulation model was developed to identify and analyze the cyclical behavior among many variables, which is the number of cattle (calves, cow, etc.), the price of cattle, the demand for beef, the desirable number of cattle, slaughter, etc. The results of this study demonstrate that dominant feedback loops between the number of cattle and livestock prices. The demand for Beef and slaughter with time delay, also the results of the simulation to explain the persistence of future price fluctuations and actions meat market until 2025.

• 한국군사과학기술학회지
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• 제13권1호
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• pp.156-163
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• 2010

A nonequilibrium molecular dynamics(NEMD) simulation method is developed and applied to study shock waves propagating through argon gas. In this simulation method, shock waves are generated by pushing a piston at a constant speed from one side of a simulation box filled with argon molecules. A linear relationship between piston speeds and shock speeds is observed. Thermodynamic properties including density, temperature, and pressure before and after the shock front are obtained from the simulations and compared with the well-known Rankine-Hugoniot equations based on ideal gases. The comparison shows an excellent agreement, indicating that this NEMD simulation method can be employed to investigate various physical properties of shock waves further.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.68-71
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• 2001

Integrated Simulation System of Aircraft is a networked virtual synthetic environment. This paper presents hardware-in-the-loop simulation, man-in-the-loop simulation, computer generated aircraft, virtual prototype of aircraft dynamics, and networked simulation system.