• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.215-221
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• 2014

To satisfy the high voltage direct current (HVDC) grid connection demand for wind power generation system, a novel topology and control strategy of HVDC grid connection for open-winding permanent magnet synchronous generator (PMSG) based wind power generation system is proposed, in which two generator-side converter and two isolated DC/DC converters are used to transmit the wind energy captured by open winding PMSG to HVDC grid. By deducing the mathematic model of open winding PMSG, the vector control technique, position sensorless operation, and space vector modulation strategy is applied to implement the stable generation operation of PMSG. Finally, the simulation model based on MATLAB is built to validate the availability of the proposed control strategy.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1633-1636
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• 2003

In this paper, we developed the scheme to grow to use newly added disk space without having to kill the application, unmount file system. This scheme, called online resizing, can resize the file system layout with the advent of Logical Volume Manager. The online resizing scheme is designed and implemented in linux cluster system where multiple hosts share the disk data in storage area network environment. It is incorporated with SANfs shared file system and can perform resizing technique with SANfs-VM volume manager. The experimental result shows that it can maximize the availability and capacity of the SANfs system which are important for modem servers where must not lose their customer.

• Journal of Korean Institute of Industrial Engineers
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• v.15 no.2
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• pp.93-101
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• 1989

The classic machine repair problem is extended to the case where a number of different machines are arranged in the sequence of operation. The steady-state availability of the system with a series of operating machines is maximized under some constraints such as total cost, available space. In order to find the optimal numbers of spare units and repair channels for each operating machine, the problem is formulated as non-linear integer programming(NLIP) problem and an efficient algorithm, which is a natural extension of the new Lawler-Bell algorithm of Sasaki et al., is used to solve the NLIP problem. A numerical example is given to illustrate the algorithm.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.198-203
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• 2003

Due to the low production cost and space availability which are originated from the structural simplicity of the torsion beam axle suspension, the suspension has been frequently used for sedan and SUV style vehicles. The design procedure of the suspension, however, requires significant amount of time which prohibits more efficient design of the suspension. In this study, an integrated procedure and constituting modules are explained and the performance of the corresponding program is exhibited. The integrated procedure enables one to save the design time and cost significantly.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.43-56
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• 2009

In korean peninsular, aircraft defense with SAM (Surface-to-Air Missile) is very important because of short range of combat space in depth. Effective and successful defense operation largely depends on two factors, SAM's location and the number of SAM for each target based on missile's availability in each SAM's location. However, most previous papers have handled only the former. In this paper, we developed Set covering model which can handle both factors simultaneously and Multi-heuristic algorithm for solving allocation problem of the batteries and missile assignment problem in each battery. Genetic algorithm is used to decide optimal location of the batteries. To determine the number of SAM, a heuristic algorithm is applied for solving missile assignment problem. If the proposed model is applied to allocation of SAM, it will improve the effectiveness of air defense operations.

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.3
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• pp.97-108
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• 1998

Spectral reflectance of the object should be measured to predict the color of object under various illuminants. The spectral reflectance can be represented in a multi-dimension space. Generally the information of inputed image by digital camera and color scanner is represented with 3-dimension color signals such as RGB. In other to predict the color of inputed image under any illuminant, we should be estimated spectral reflectance of the object. In this paper, we described the method to predict spectral reflectance by einenvector using the skin color of printed image, confirmed availability and propriety through experiment. we estimated spectral reflectance of skin color taken by RGB color signals and than reproduced skin color according to various illuminants on CRT.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.856-858
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• 2001

분산 파일 시스템에서 파일을 복제하는 목적의 하나는 파일의 가용성을 높이는 것이다 서버들로 이루어진 시스템에서 가용도 문제는 주로 오류 상황이 대상이다 반면에 데스크탑으로 구성된 경우 각각이 상대적으로 가용도가 낮고 그 편차도 커서 파일의 가용도를 최적화 하도록 복제본을 저장하는 것이 기본적인 문제가 된다. 파일 단위 복제 기법에서는 파일 수가 참여 시스템 수에 따라 기하급수적으로 증가하고 파일 배치 때마다 가용도 최적화를 수행해야 하는 문제가 있다. 본 논문에서는 저장 공간 단위 복제 기법을 제안한다. 데스크탑 시스템의 저 장롱간을 고정 크기의 페이지들로 나누고 이들을 조합해서 일정한 가용도를 가지는 페이지 그룹을 형성한다. 파일들은 이 페이지 그룹에 저장된다. 페이지의 개수가 파일 수가 아닌 시스템 수에 의존하고, 파일 배치 시점과 무관하게 페이지 그룹을 만들 수 있는 장점이 있다. 최종 가용도를 높이고 연산 시간을 줄이기 위해 ILS(Iterated Local Search )방법을 이용만 탐색을 수행한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.617-620
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• 2000

In this paper, we show an application of constraint logic programming to the operation scheduling on machines in a job shop. Constraint logic programming is a new genre of programming technique combining the declarative aspect of logic programming with the efficiency of constraint manipulation and solving mechanisms. Due to the latter feature, combinatorial search problems like scheduling may be resolved efficiently. In this study, the jobs that consist of a set of related operations are supposed to be constrained by precedence and resource availability. We also explore how the constraint solving mechanisms can be defined over a scheduling domain. Thus the scheduling approach presented here has two benefits: the flexibility that can be expected from an artificial intelligence tool by simplifying greatly the problem; and the efficiency that stems from the capability of constraint logic programming to manipulate constraints to prune the search space in an a priori manner.

• Journal of the Korean housing association
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• v.16 no.5
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• pp.83-90
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• 2005

This study aimed to examine the possibility of remodeled nursing home utilizing a closed school in Kunsan, where the number of closed schools increases and the ratio of elderly population grows. Major contents of research were understanding architectural characteristics of closed school and elderly housing in the sample area, and a suggestion of remodeling a closed school into nursing home. Conclusions can be summarized as follows; understanding the high ratio of elderly population and increases of closed schools in sample area, verification of overall possibility in remodeling a closed school into elderly facility, confirmation of availability in changing regular class room to residential rooms, and some proposals of principal points in floor planning - homelike atmosphere by small scaled residential units(10 persons), spatial hierarchy for residents' mental comfort, sliding door for accessibility, kitchen and dining space in residential unit for the residents' participation in houseworks.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.379-381
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• 2003

155Mbps 단거리용 무선 광통신 모듈을 120m 의 짧은 거리에 설치하였다. 그 결과 99.98% 이상의 error free availability와 99.99% 이상의 severely error free second rating을 가졌다. error의 요인을 분석한 결과 30mm/h 정도의 비에도 크게 영향을 받지 않음을 알 수 있었다. 맑은 날에도 error가 발생하였는데 그 원인은 날아가는 새와 같은 물체가 링크를 가리기 때문이었다.