• CDE review
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• v.11 no.2
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• pp.15-22
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• 2005

Presented in the paper is an approach to developing an intelligent mold shop as a means to overcome the difficulties faced by mold-makers due to skill shortages and increased global competition. A machine shop where as much as of the human skills are replaced by a set of intelligent systems is called an intelligent machine shop, and an intelligent mold-making machine shop is called an intelligent mold shop(MS). By analyzing the contents of operator's skill. three intelligent S/W stations have been designed: Technical Data Processing(TDP) Station, Loading Schedule Station, and Real-time Monitoring Station. A detailed architecture of the TDP station is described, and measures of effectiveness of IMS are elaborated.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.144-144
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• 2018

• Journal of the Korean Society of Systems Engineering
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• v.14 no.1
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• pp.36-43
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• 2018

The availability of the weapon system can be analyzed through state modeling and simulation using the Markov process. In this paper, show how to analyze the availability of the weapon system and can use the Markov process to analyze the system's steady state as well as the RAM at a transient state in time. As a result of the availability analysis of tracked vehicles, the inherent availability was 2.6% and the operational availability was 1.2% The validity criterion was defined as the case where the difference was within 3%, and thus it was judged to be valid. We have identified the faulty items through graphs of the number of visits per state among the results obtained through the MPS and can use them to provide design alternatives.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.199-201
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• 2008

This paper persents charge/discharge system for small PV using micro-processor. Charge/discharge system designs a Buck converter and using constant voltage charge system because regular voltage is rather high a condenser. Besides, we did compensate for charge voltage of condenser through a temperature compensation circuit. We consists of a 170W stand-alone PV system to observe charge/discharge system character. In the result of search about output character we know that charge and discharge are smoothly running.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.163-169
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• 2005

Micro hole is ode of basic elements for micro device or micro parts. Micro electrochemical machining (ECM) can be applied to the machining of micro holes less than 50 ${\mu}m$ in diameter, which it is not easy to apply other techniques to. For the machining of passivating metals such as stainless steel, machining conditions should be chosen carefully to prevent a passive layer. The machining conditions also affect the machining resolution, In this paper, machining characteristics of micro ECM were investigated according to machining conditions such as electrolyte concentration and pulse conditions. From the investigation, optimal machining conditions were suggested for micro ECM of stainless steel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1202-1205
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• 2005

Micro hole is one of basic elements for micro device or micro parts. By micro ECM, micro holes less than $50\mu{m}$ in diameter can be machined easily. Machining characteristics of micro ECM were investigated according to machining conditions such as electrolyte concentration and pulse conditions. From the investigation, optimal machining conditions were suggested for micro ECM of stainless steel. For the micro machining with high resolution, the change of machining gap should be predicted. By using electrochemical principle equations, the change of machining gap was simulated.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.69-75
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• 2006

In this paper, micro electrical discharge milling using deionized water as dielectric fluid was investigated. In EDM, dielectric fluid is an important factor which affects machining characteristics. When deionized water was used as dielectric fluid, machining characteristics were investigated according to voltage, capacitance, and resistivity of deionized water. Machining gap increased with increasing voltage and capacitance. As the resistivity of deionized water decreased, the machining gap increased. The wear of a tool electrode and machining time can be reduced by using deionized water instead of EDM oil. Surface roughness was also improved when deionized water was used.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.746-752
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• 2005

본 논문에서는 다층 퍼셉트론 신경망 학습을 위한 새로운 두 단계 학습방법을 제안하고 이를 옵션 가격결정 모형에 응용하였다. 제안된 신경망 학습 알고리즘의 첫번째 단계는 Levenberg-Marquardt 알고리즘을 이용하여 빠르게 국소최적해를 찾는 것이고 두 번째 단계는 첫 번째 단계에서 찾은 국소최적해가 원하는 수준에 미치지 못할 경우 선형탐색 터널링을 이용해서 더 나은 해를 찾는 것이다. 이 두 단계를 반복적으로 수행함으로써 연결가중치 공간에서 구하고자 하는 해를 빠르고 안정적으로 찾을 수 있다. 현재 옵션가격결정 모형으로 많이 이용되고 있는 Black-Scholes 모형의 문제점을 극복하기 위해서 제안된 신경망 모형을 옵션가격결정 문제에 사용하였다. 이 모형을 KOSPI200 옵션 데이터로 실험한 결과 Black-Scholes 모형에 비해 검증오차를 60% 가량 줄일 수 있었다.

• Tunnel and Underground Space
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• v.14 no.6 s.53
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• pp.423-428
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• 2004

The stability of tunnels is usually analyzed as plain strain condition and rock bolts are assumed as 2 dimensional equivalent continuum structures. In this study, 2 and 3 dimensional numerical analyses were conducted to verify the validity of 2 dimensional analysis of rock bolts. Since the results of 2 dimensional analysis showed more than $10\%$ differences in poor rocks, it seems that 3 dimensional analysis is required in poor rocks.

• Journal of Korean Foot and Ankle Society
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• v.13 no.2
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• pp.211-213
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• 2009

Pigmented villonodular synovitis (PVNS) is a rare proliferative disorder that affects synovium, tendon sheath and bursa. Although the condition can present in any joint, knee joint is the most commonly affected site and only 2.5% of cases occur in foot and ankle joint. PVNS occurs in two types: localized and diffuse. Localized type is characterized by focal involvement of the synovium with either nodular or pedunculated masses, Diffuse type affects virtually the entire synovium. Diffuse type has reported more recurrence rate. We have experienced a patient who has diffuse type PVNS of ankle joint and report an optimal method of surgical treatment.