• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.353-356
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• 2005

We developed a dynamic model of PEM fuel cell system which can analyze its transient response to dynamic load current. System components such as compressor, air cooler, humidifier, and stack were modeled based on their dynamic equations and performance maps by using Matlab Simulink platform. Through this simulation model, dynamic characteristics of fuel cell system including oxygen excess rat io, stack voltage, and system efficiency were shown. In addition to that, we briefly analyzed the humidity effect on cathode pressure and system efficiency, expecting that this model can be further used to optimize fuel cell system parameters just like operating pressure and temperature, humidity and oxygen excess ratio.

• 한국정밀공학회지
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• 제16권12호
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• pp.214-221
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• 1999

In this research, a power-assisted steering system is modeled as a part of a full vehicle dynamic model. The dynamic model of the steering system incorporates hydraulic and dynamic relations between major parts of a steering system, such as steering column, control valve, rack and pinion gear. Through an experimental setup of the steering system, the steering system model is validated. The steering model is included in a full vehicle dynamic model of a car, where kinematic relations between steering and suspension system are defined, and various simulations are performed to evaluate the performance of steering system in conjunction with overall dynamic performance of the vehicle.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.218-225
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• 2000

Recently, right rail transit (L.R.T.) systems become influential as a new traffic system in urban area to solve heavy traffic problems. However, there are little research results about the dynamic interaction problems between the vehicle and structural system, even though some studies far those static problems have been carried out. Therefore, first of ail, the dynamic equations of an interaction between vehicle system and surface roughness of the vehicle path are derived before developing the dynamic equations of vehicle-structure-surface roughness system, in this study. As a vehicle model, an automated guide-way transit (A.G.T.) system is adopted. Parametric study shows that the dynamic wheel loads of the vehicle system has a tendency to increase with vehicle speeds and stiffness of suspension system. However, those dynamic wheel loads have tendencies to decrease in according to loads of the vehicle system.

• 대한기계학회논문집
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• 제17권12호
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• pp.2949-2961
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• 1993

Dynamic cutting process can be represented by a closed-loop0 system consisted of machine tool structure and pure cutting process. On this paper, cutting system is modeled as a six degrees of freedom system using MARV(Modified Autoregressive Vector) model in face milling, and the modeled dynamic cutting process is used to predict dynamic cutting force component. Based on the double modulation principle, a dynamic cutting force model is developed. From the simulated relative displacements between tool and workpiece the dynamic force domponents can be calculated, and the dynamic force can be obtained by superposition of the static force and dynamic force components. The simulated dynamic cutting forces have a good agreement with the measured cutting force.

• 한국멀티미디어학회논문지
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• 제5권3호
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• pp.331-341
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• 2002

기존의 슬라이싱 기법들은 슬라이스를 생성하며 생성된 슬라이스의 정확성을 위해 종속 그래프를 사용한다. 그러나, 기존의 많은 슬라이싱 기법들은 동적 슬라이싱 기법에 바탕을 두고 데이터 통신 링크를 표현하기 때문에 많은 정점들(vertices)과 간선들(edges)을 필요로 한다. 그러므로 그 그래프는 매우 복잡하다. 어떤 프로그램 시스템에 대한 소프트웨 어 슬라이싱을 처리하기 위해 본 논문에서는 동적 시스템 종속그래프를 제안한다. 그리고, 소프트웨어 시스템의 동적 슬라이스를 산출하기 위해 관련 테이블들의 관계도를 이용한 효율적인 슬라이싱 알고리즘을 제안한다. 동적 슬라이스의 생성을 위한 동적시스템종속그래프는 제안된 알고리즘으로부터 얻어진 마킹테이블을 사용해서 얻어진다. 슬라이스의 최종 결과는 이 그래프를 추적함으로써 얻어진다. 결론적으로 제안된 동적시스템종속그래프 기법의 효율성을 기존의 종속그래프 기법과 비교하였다.

• International Journal of Air-Conditioning and Refrigeration
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• 제15권4호
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• pp.147-155
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• 2007

Mobile air conditioning systems work under widely changing operating conditions. To understand the system behavior under such dynamic conditions, a test facility that can impose transient loads as well as conducting dynamic measurements is needed. To test mobile air conditioning systems including their dynamic performance under various drive cycle patterns without using full scale vehicles in a wind tunnel, a new test facility, called "dynamic simulator," is described. It can replicate real vehicle operating conditions by interacting with the system being tested based on the measured system performance and subsequently adjusting the air properties returning to the test system based on the results of a numerical cabin model. A new dynamic simulator has been designed, constructed, and verified for performing dynamic tests. It was successful in controlling the temperature and relative humidity of the air returning to the test unit within ${\pm}0.7^{\circ}C$ and ${\pm}4%$ of their respective intended values. The verification test under the New European Driving Cycle demonstrated that detailed transient behavior of the mobile air conditioning system could be measured by using this dynamic simulator.

• International Journal of Precision Engineering and Manufacturing
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• 제4권6호
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• pp.38-43
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• 2003

In this study, the optimal dynamic absorbing system for the gas operated HIF (high implusive force) device has been investigated. For this purpose, firstly, the dynamic behavior of human body induced by impulsive disturbances has been analyzed through a series of experimental works using the devised test setup. The characteristics of linear impulse has been compared under some conditions of support system. In order to design the optimal dynamic absorbing system, the parameter optimization process has been performed based on the simplified isolation system model under constraints of moving displacement and transmitted force. Finally, the performance of the designed dynamic absorbing system has been evaluated by simulation in the actual operating condition.

• 한국철도학회논문집
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• 제9권5호
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• pp.561-568
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• 2006

Dynamic equations of motion for the interaction system of bridge and vehicle are derived to investigate the dynamic responses of bridge and vehicles induced by moving automated guide-way transit(AGT) vehicle and surface roughness of bridge. The vehicle model for ACT vehicle is idealized as 11 DOF including yawing, lateral translation and steering of wheels, and the bridges are modeled with finite element method. The AGT vehicle model was verified by experimental study. Parametric studies are carried out to investigate the effect of vehicle speed, surface roughness, stiffness and damping of the suspension system, AGT vehicles and dynamic wheel loads of the AGT vehicles. From the parametric study it can be seen that the dynamic incremental factor of the bridge and dynamic responses of vehicles have a tendency to increase with vehicle speeds, surface roughness and the stiffness of AGT vehicle suspension system. On the other hand those dynamic wheel loads have tendencies to decrease in according to increase of damping of the suspension system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.541_542
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• 2009

This paper reviews the definition and background of dynamic pricing which is the essential element of demand response system. Also, economic efficiency and related issues on dynamic pricing are studied. Several issues on design and operation of demand response system, which can implement the dynamic pricing, are described. Therefore the results will be helpful for developing the demand response system with dynamic pricing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.50_51
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• 2009

This paper describes the novel real-time embeded Dynamic System Monitor(KDSM) for dynamic device modeling and disturbace monitoring. The KDSM uses the variable resampling technique together with DFT algorithm so that it overcomes the shortcomings of the existing DFT algorithm at the big deviation of network frequency. The suggested algorithm is implemented by using the NI-PXI system, and verified by applying to the generator testing.