• 산업공학
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• 제11권2호
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• pp.177-190
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• 1998

The work-order performs an important role in make-to-order production. The development of work-order system in this production is more complex than work-order system in planing production. To construct work-order system, load of directors for work-order must be decreased, and production management between scheduling of master plan and current workshop conditions must be considered. In this study, we grasped troubles in present work-order system and flows of information for work order. Using these results are made database schemas and data flow diagrams for effective development of work-order system. And then, for successful establishment of work-order system and actual use of directors, we considered systematic and easy user-interface. For a case study, development procedures of work-order system are presented for plant factory.

• 대한수학회지
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• 제45권2호
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• pp.405-423
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• 2008

By using critical point theorem, we study a higher order difference system, and obtain some new sufficient conditions ensuring the existence of periodic solutions for such a system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.54.3-54
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• 2001

This paper presents a controller design technique for standard 2nd-order system satisfying user-specified phase margin. A simple method is presented to meet stability margin for the 2nd-order system, which is important since the 2nd-order plant models are frequently encountered in the practical plant models such as actuators of the optical drive systems. Through the comparison of the specified stability margin and achieved stability margin, it is shown in the simple example that the proposed technique is useful in the initial design of control systems with stability margin specifications.

• Journal of Power Electronics
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• 제17권2호
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• pp.453-463
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• 2017

This paper discusses the measurement of frequency response functions for various dc-dc converters. The frequency domain identification procedure is applied to the measured frequency responses. The identified transfer functions are primarily used in developing behavioral models for dc-dc converters. Distributed power systems are based upon such converters in cascade, parallel and several other configurations. The system level analysis of a complete system becomes complex when the identified transfer functions are of high order. Therefore, a certain technique needs to be applied for order reduction of the identified transfer functions. During the process of order reduction, it has to be ensured that the system retains the dynamics of the full order system. The technique used here is based on the Hankel singular values of a system. A systematic procedure is given to retain the maximum energy states for the reduced order model. A dynamic analysis is performed for behavioral models based on full and reduced order frequency responses. The close agreement of results validates the effectiveness of the model order reduction. Stability is the key design objective for any system designer. Therefore, the measured frequency responses at the interface of the source and load are also used to predict stability of the system.

• 대한지리학회지
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• 제46권2호
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• pp.115-133
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• 2011

야마다의 산지차수구분법은 상향식으로 정의할 수 있는데, 이는 저차수 산지들이 모여 점차 차상위차수 산지를 이룸과 동시에 산지의 영역과 규모가 확대되기 때문이다. 하지만 산지를 총체적으로 이해하고 각종 산지 정보를 체계적으로 관리하기 위해서는, 특정 규모의 산지를 이루는데 기여한 차하위차수 산지만을 강조하는 야마다의 산지구분법에는 한계가 있다. 왜냐하면 상위차수 산지내에는 차하위차수 산지뿐만 아니라 독립된 차차하위, 차차차하위 산지도 포함되어 있기 때문이다. 이와 같은 문제점을 해결하기 위해 본 연구에서 제시된 산지분류법은 기본적으로 하향식이다. 여기서 하향식이란 최고위차수 산지를 구성하는 차하위차수 산지, 다시 이를 구성하는 차차하위차수 산지로 산지를 세분해나가 최종적으로 2차수 산지를 구성하고 있는 1차수 산지까지 분류해 나가는 것을 의미한다. 본 연구에서는 야마다 산지차수구분법을 근간으로 특정 산체를 구성하고 있는 모든 산지 요소를 체계적으로 분류하고 구분된 산지에 대한 새로운 명명법을 제시함으로써 산지정보의 종합적 체계적 관리를 위한 데이터베이스의 근간을 마련했다.

• 수산경영론집
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• 제22권1호
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• pp.1-52
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• 1991

This study deals with the evolutional history of the holding and utilization of fisheries resources in Korea. Fisheries resources have the basic characteristics of the density dependent self-regulating renewable and common property resources, Irrational utilization of fisheries resources is mainly due to the unlimited access to the resources. The holding and utilization of fisheries resources in Koryo era was opened to everyone. But it was nationalized in the early Yi Dynasty. The purpose of its nationalization was to provent the paticular powered-man with their monoplized holding and to levy fisheries tax. Eoeop-peop, the first modern fisheries law in Korea, was enacted as a part of the invasion policy of Japan in 1908. With the japanese annexation of Korea in 1910, the Japanese Government established a new institutional system of fisheries as a part of an overall reformation of the institutional for an implementation of the colonial policy. It was very the new enacted Fisheries Law (Gyogyorei). Also the Government enacted compulsorily another new Fisheries Law (Chosen Gyogyorei) with its adjunct laws and regulations revise the institutional system of fisheries on May 1, 1930. After Eoeop-peop enactment, the fisheries resources in Korea could be used only under the license, permission, and statement. After Korea was from Japan in 1945, Korea Government at last enacted the new fisheries law (Susaneop-peop) in 1953. The goal of Susaneop-peop was to achive the general usage and protection of the fisheries resources, and to attain the development and democratization of the fishery in Korea. This law was amended 13 times until 1990. The license fishery have a legal right on the fishery, called a fishery rigt. This right means a right of exclusive occupation and utilization of a unit of the inshore fishing grounds. The main evolutional issues of license fishery are as the following : 1) the foundation of the exclusive usable fishery right(1911, Gyogyorei), 2) the deletion of the settled U9space lift net and settled space sein net fishery, and the expansion of the cooperative fishery-No.1, 2, and 3 type cooperative fishery-(3rd amendment, 1963), 3) the deletion of the No.2 and 3 type cooperative fishery, and the separation of the culturing fishery in No.1 and 2 type culturing fishery (13th amendment, 1990). The effective period of the license fishery was amended as the following : 1) 1908(Eoeop-peop) : within 10 years, renovation system, 2) 1929(Chosen Gyogyorei) : within 10 years, unlimited extension system, 3) 1971. 7th amendment : 10 years, renovation system, 4) 1972. 8th amendment : 10 years, only 1 extension system, 5) 1975. 9th amendment : 5-10 years, only 1 extension system, 6) 1990.13th amendment : 10 years, within 10 years of total extensional years. The priority order of the fishery license was established in 1953 (Susaneop-peop). The amendment of it is as follows : 1) 1953. enactment \circled1 the fishing grounds that the fishery right is extablished 1st order : the existing fishery right man, unlimited renovation 2nd order : the corporate that the regional fisherfolk organized 3rd order : the rest experienced fishermen \circled2 new fishing grounds 1st order : the corporate that the regional fisherfolk organized 2nd order : the rest experienced fishermen 2) 1971. 9th amendment \circled1 the fishing grounds that the fishery right is established 1st order : the existing fishery right man, unlimited renovation 2nd order : the Eochongye that the regional fisherfolk organized 3rd order : the regional fishery cooperative that the regional fisherfolk organized 4th order : the rest experienced fishermen \circled2 new fishing grounds 1st order : the Eochongye that the regional fisherfolk organized 2nd order : the regional fishery cooperative that the regional fisherfolk organized 3rd order : the rest experienced fishermen 3) 1981. 10th amendment \circled1 the inside of No.1 type cooperative fishing grounds 1st order : the Eochongye that the regional fisherfolk organized 2nd order : the regional fishery cooperative that the regional fisherfolk organized 3rd orer : the rest experienced fishermen 4) 1990. 13th amendment \circled1 No.1 type cultural fishery 1st order : the Eochongye that the regional fisherfolk organized 2nd order : the regional fishery cooperative that the regional fisherfolk organized 3rd order : the rest experienced fishermen \circled2 No.2 type cultural and settle fisher : general priority order The effective period of the permission fishery was amended 6 timed. First, it was within 5 years and renovation system (Eoeop-peop). Now it is 5 years and renovation system. The effective period of the statement fishery was amended 4 times. First, it was within 5 years, and then was amended within 3 years(Chonsen Gyogyorei). Now it is 5 years.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.507-515
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• 2013

This paper proposes a compensation method for the $2^{nd}$-order harmonic of single-phase grid-connected wind power generation systems. Theoretically, a single-phase grid-connected inverter system has no choice but to cause the $2^{nd}$-order harmonic to DC-link voltage. The reference active current is affected by the DC-link voltage. The output current from the reference active current is distorted by the $1^{st}$ and $3^{rd}$-order harmonic. The proposed method can compensate, conveniently, the reference active current with the $2^{nd}$-order harmonic. To reduce the $2^{nd}$-order ripple in the reference active current, proposed method takes a PR controller as a feed-forward compensator. PR controllers can implement selective harmonic compensation without excessive computational requirements; the use of these controllers simplifies the method. Both the simulation and experimental results agree well with the theoretical analysis.

• Transactions on Control, Automation and Systems Engineering
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• 제4권4호
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• pp.283-288
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• 2002

This paper has shown that the impulse and the unit step responses of 2nd-order systems can be computed by an analytic method. Three different 2nd-order systems are investigated: the prototype system, the system with one LHP(left half plane) real zero and the system with one RHP(right half plane) real zero. It has also shown that the effects of the LHP or the RHP zero are very serious when the zero is getting closer to the origin on the complex plane. Based on these analytic results, this paper has presented two sufficient and necessary conditions for 2nd-order linear SISO(single-input/single-output) stable systems to have the nonovershooting and the monotone nondecreasing step response, respectively. The latter condition can be extended to the sufficient conditions for the monotone nondecreasing step response of high-order systems.

• 한국의류학회지
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• 제20권1호
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• pp.43-53
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• 1996

This study was initiated to investigate (1) the current sizing system for mail-order clothing, (2) consumers' preference for sizing systems, and (3) consumers' satisfaction with garment size. The apparel items and the sizes available at various mail-order companies in Korea were also reviewed. This investigation of consumers' preferences for various size description systems includes a survey of 410 men and women who had purchased garments by mail-order. The data were analyzed by Statistical Analysis System/pc. The major results are as follows; 1. The sizing system of mail-order clothing was different by garment items. The number of apparel sizes available for mail-order purchasing was three or less. The most mail∼order garments were labeled by the numerical size codes of body girth nleasurements or letter code (S, M, L). 2. The size description system most prefered by female subjects(N : 360) was the numerical size code of a body measurement(55.4%). The combination of bust-hips-height measurements size codes were prefered by 13.3% . The pictogram was least premiered by the subjects. 3. The apparel items that subjects wanted to buy using mail-order were underwear, home -weat and night-wear. The heavy users of mail-order purchasing, however, also wanted to purchase expensive garments requiring precise fit. The subjects aged from 20's to 80's wanted to purchase childern's wear by mail. 4. The desire for diversity of garment item and size of mail-order apparel was relatively high. The subjets also wanted to purchase special size garments by mail-order, e. g., garment sizes for full or tall figure.

• 한국산업정보학회논문지
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• 제7권5호
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• pp.1-10
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• 2002

본 논문에서는 B2B 수주ㆍ발주 시스템 구현에 앞서 우선 사용자의 요구사항을 시나리오로 작성하였다. 그리고 사용자의 요구사항을 보다 정확하고 쉽게 파악하기 위하여 시나리오로 작성한 명세서(specification)를 UML에서 이용되는 여러 Diagrams들을 이용하여 그래프로 나타내었다. 이들 명세서에 대해 XML을 이용하여 국내 알루미늄 제조 회사인 N사를 대상으로 B2B 수주ㆍ발주 시스템을 구현하였다. 본 연구의 결과로는 첫째, 개발하고자 하는 문제들을 UML을 이용하여 명세화 함으로서 개발자나 사용자가 모두 명확하게 이해할 수 있었다. 둘째, 개발자와 사용자간에 의사소통(communication)이 원할 하였다. 셋째, 형식화된 명세서로 인해 프로그래밍하기에 쉬웠다. 넷째, 영업팀에서의 신속한 업무처리가 가능하고, 재고관리가 원할 하였다. 다섯째, 주문 예약관리가 신속해지고 정확성을 도모하였다. 여섯째, 수주 및 발주 업무를 직거래로 할 수 있었다. 일곱째, 원자재 발주와 수주에 대한 신속성과 간소화로 인한 비용절감을 도모할 수 있었다. 여섯째, 알루미늄 기물에 대한 홍보효과를 가져올 수 있었다.