• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.131-142
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• 2005

This paper proposes queueing models for a Web server system which is composed of an infinite-buffer main server and finite-buffer auxiliary server(s). The system is modeled by the level-dependent quasi-birth- death (QBD) process. Utilizing the special structure of the QBD, we convert the infinite level-dependent QBD into a finite level-independent QBD and compute the state probabilities. We then explore the operational characteristics of the proposed web-server models and draw some useful conclusions.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.69-80
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• 1999

A genetic algorithm to determine the optimal signal sequence and double cycle pattern is described. The signal sequence and double cycle pattern are used as the input for TRANSYT to find optimal signal timing at each junction in the area traffic networks, In the genetic process, the partially matched crossover and simple crossover operators are used for evolution of signal sequence and double cycle pattern respectively. A special conversion algorithm is devised to convert the signal sequence into the link-stage assignment for TRANSYT. Results from tests using data from an area traffic network in Leicester region R are given.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.330-334
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• 2000

This paper proposes a new double-connected 3-phase voltage source inverter with improved output voltage waveform. An auxiliary single-phase inverter injects a ripple voltage into the double- connected inverter to convert 12-step operation to 36-step operation. The KVA rating of the output phase-shifting transformer is reduced by employing a harmonic canceling reactor. The whole rectifier-inverter system including the proposed technique is introduced and the experimental results are provided.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.77-79
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• 2004

A typical conventional systems of a linear motion use rack and pinions or ball screws to convert rotary motions from DC servo motors. A linear motor has been used a several field for a MEMS technology and a aircraft carrier. We was studied a transient response of a linear actuator with a damping ratio, spring constant and a pressed power.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1158-1160
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• 1992

A new dc/ac soft switched PWM convert having a dc-link commutation circuit is proposed. The commutation circuit implemented by utilizing a series resonant circuit while preparing for zero voltage switching of primary inverter. The converter provides both variable pulse width and position which is fundamentally different than converters. In this paper, the operating principles, design and control considerations analysis of a such a soft switched converter is analyzed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.889-893
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• 1995

This paper verified error of STL file and presented a new application of reformed division method for reducing to appeared error by using Delaunay triangulation method that used to modify error of verified data. First, it is analyzed each vertices in hole error and classified follow case that is 1. case of plan or slope, 2. case of edge, 3. case of apex and 4. case of rapid curve, and reduced volume tolerance between original model and converted model after convert STL file.

• Korean Journal of Environmental Agriculture
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• v.8 no.2
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• pp.136-141
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• 1989

An alternative method for the synthesis of sulfonylurea derivatives, some of which considered to be a new recommendable herbicides, with oxalylchloride was investigated. Sulfonamides read with oxalylchloride to sulfonyloxamoylchlorides, which convert easily under pyrolysis to sulfonylisocyanates. The isocyanates react further with amines to yield corresponding sulfonylurea derivative quantitatively.

• Journal of Korean Library and Information Science Society
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• v.25
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• pp.207-223
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• 1996

Nowadays, the wide spectrum of changes have been occurred in library world. It is essential for librarians to improve their professionalization standards to convert these changes into the o n.0, pportunity of growth. The device of improvement of professionalization standards is following: 1. Librarians have to receive formal and informal education and learn to advance in knowledge and skill concerning library affairs continually. 2. Self learning has to be transform into learning organization. 3. Education of Librarianship concentrate mainly in practical and technical study by this time but it is indispensable to develop the theory and philosophy of librarianship.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.347-348
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• 2015

최근 들어 3D데이터의 필요성이 대두되면서 여러 콘텐츠가 개발되고 있다. 2D image를 3D로 변환하기 위해 Canny 에지 검출알고리즘을 이용하였다. 이와 같은 3D 모델로 제작한 데이터는 3D 애니메이션이 가능하므로 과학관 등의 전시실에 활용 할 수 있다.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.4
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• pp.37-50
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• 1997

We consider the channel allocation problem for the earth orbit (LEO) satellite systems. This problm is known to be NP-complete and a couple of heuristic algorithms have been developed. In this paper, we convert the problem into a simpler form through the concept of pattern. And we suggest another algorithm based on Simulated Annealing for this simplified problem. The results of performance comparison show that our method works very well. Simulation results are reported.