• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.795-800
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• 2001

In this study, a program to design a multi-stage axial compressor is developed wi th mean-line analysis and vortex methods. In a preliminary design stage, a method. to design in a short time is needed and mean-line analysis is usually used for this purpose. Arbitrary pressure ratio and reaction can be assigned to generate overall geometry and several vortex methods are adopted to consider the radial distribution of velocity and reaction. The variation of performance, when we use free vortex, forced vortex, and exponential method, is compared and discussed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.406-410
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• 1990

This paper presents an approximate analysis of the serial production lines using decomposition technique. A serial production line consists of a series of unreliable machines separated by finite buffers. The serial production line is evaluated by approximation method, the results of which are compared with those examined by the discrete time event simulation, based on this approximation method, a gradient technique is proposed, which improves the efficiency of an operation of production line through the re-allocation of buffers.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.167-171
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• 2004

The Spar platform with deep draft is characterized as effective structure in extreme wave condition, which has larger natural period than that of waves in sea. In this paper, the time simulation of motion responses of Spar with catenary mooring line is presented in irregular waves. The memory effect is modeled by added mass at infinite frequency and convolution integrals in terms of wave damping coefficients. The added mass, wave damping coefficients and wave exciting forces are obtained from three-dimensional panel method in the frequency domain. The motion equations are consisted of forces for inetia, memory effect, hydrostatic restoring, wave exciting and mooring line. The forces of mooring line are modeled as quasi-static catenary cable.

• 대한기계학회논문집A
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• 제26권5호
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• pp.843-850
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• 2002

This paper presents a simulation method using the transmission line modeling to reduce simulation runtime of hydraulic control systems. This method is based on separating the system components each other using the transmission line elements prior to simulation, which leads to divide the simulated system into several subsystems suitable for an even more efficient integration. It can also handle nonlinearities and discontinuities without flag signal when restarting integration. By applying variable integration timestep to parallel hydraulic circuits via parallel processing, it is shown that simulation run-time can be reduced significantly compared with that of Runge Kutta method.

• 한국전자파학회지:전자파기술
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• 제6권4호
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• pp.11-19
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• 1995

본 논문에서는 시간영역 유한차분법(Finite Difference Time Domain : FDTD) 에 의해서 동축선로의 전달계수와 차폐효과에 대하여 해석하고 그 결과를 모멘트법과 비교하였다. 기존의 여기방법인 TE 나 TM 모드를 대신하여 반사파의 빠른 시간내의 완전흡수를 위하여 TEM 모드로 가정한 Gaussian 펄스를 인가하는 방법을 사용하였다. 또한, 동축선로의 차폐효과를 FDTD를 이용하여 계산 결과와 모멘트법을 이요하여 얻은 결괄와 매우 유사한 결과를 얻었다.

• 대한조선학회논문집
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• 제41권5호
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• pp.1-7
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• 2004

The Spar platform with deep draft is characterized as effective structure in extreme wave condition, which has larger natural period than that of waves in sea. In this paper, the time domain simulation of motion responses of Spar with catenary mooring line is presented in irregular waves. The memory effect is modeled by added mass at infinite frequency and convolution integrals in terms of wave damping coefficients. The added mass, wave damping coefficients and wave exciting forces are obtained from three-dimensional panel method in the frequency domain. The motion equations are consisted of forces for inertia, memory effect, hydrostatic restoring, wave exciting and mooring line. The forces of mooring line are modeled as quasi-static catenary cable.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2049-2057
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• 2014

In this paper, a numerical method for analyzing coupling between high-altitude electromagnetic pulse (HEMP) as external field and a shielded twisted pair (STP) cable is proposed, which is based on an expanded chain matrix. Load responses of electromagnetic (EM) field excitation in uniform transmission line (TL) are solved by Baum-Liu-Tesche (BLT) equations in frequency domain, however, it is difficult to apply BLT equations to solve load responses of STP cable because the iteratively changing configuration of each twisted pairs are involved in cable. To avoid this problem and decrease memory and CPU time, we proposed the expanded chain matrix modeling method that is calculated using ABCD parameters, and applied multi-conductor transmission line (MTL) theory to consider the EMP coupling effectiveness of each twisted pairs. The results implemented by the proposed method are presented and compared with those obtained by the finite-difference time domain (FDTD) method as a kind of 3D full wave analysis.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1129-1135
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• 1993

For successful implementation of robotic painting system, a structured design and analysis procedure is necessary. In designing robotic system, both functional and economical feasibility should be investigated. As the robotization is complicated task involving implementation details(such as robot selection, accessory design, and spatial layout) together with operation details, a computerized method should be sought. However, any conventional robotic design system and off-line programming system cannot accomodate such a need. In this research, we develop an interactive design support system for robotization of a cycle painting line. With the developed system called SPRPL(Simulation Package for Robotic Painting Line) users can design the painting objects(via FRAME module), select robot model (ROBOT), design the part hanger (FEEDER), and arrange the workcell. After motion programming (MOTION), the design is evaluated in terms of: a) workspace analysis, b) coating thickness analysis, and c) cycle time (ANALYSIS). By iterative design and evaluation procedure, a feasible and efficient robotic design can be attained. As the developed system has motion planning and analysis features, it can be also used as an off-line robot programming system in operation stage. Including the details of each module, this paper also presents a case study made for an actual painting line.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1338-1343
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• 2004

The Debao pony ear marginal tissue fibroblast cell line (NDPEM 2/2) was uccessfully established using either primary explant technique or collagenase technique. The characterizations of the cell line were identified as following: the cells were adherent and of density limitation; population doubling time (PDT) of cells made with the two techniques were 35.9 h and 48 h, respectively; chromosome analysis showed that the frequency of cell chromosome number to be 2n=64 was 91.3%-92.8%. Confirmed by isoenzyme analysis, this cell line had no cross- contamination. Tests for microbial contamination from bacteria, fungi, virus or mycoplasma were negative. This newly established cell line meets all the standard quality controls of ATCC. It will provide a precious genetic resource for the conservation of the Debao pony breed, as well as effective experimental material for genetic studies on Debao ponies.

• 한국철도학회논문집
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• 제15권1호
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• pp.88-95
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• 2012

현재 도시철도의 열차운행계획 수립과정은 열차 운용에 필요한 철로의 구조, 역사 내 철로 구조, 차량 정비시간 등 다양한 제약조건을 고려하여 이루어 지기 때문에, 매우 복잡한 구조를 가지게 되는 문제점이 있다. 이러한 문제점들로 인하여 다양한 열차운행 시간표(Time-Table)에 대한 비교 분석에 큰 어려움이 있다. 본 연구는 도시철도 운행계획 수립의 효율성 및 체계성을 제고하기 위하여, 철도 운행계획 수립 과정 중 수립 가능한 다양한 차량 시간표(Time-Table)의 기대효과를 열차다이아 작성 이전에 비교분석하여 가장 효과적인 차량 투입계획 및 운행일정을 선정할 수 있도록 하는 방법론을 제시하고자 한다. 본 연구에서는 열차 운행 시간표(Time-Table)을 분석하기 위하여 Line-Blocking 이론을 활용하였으며 광역철도 4호선중 사당~안산 구간을 대상으로 사례 분석하였다.