• Title/Summary/Keyword: 김철환

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A study of Neural Network based adaptive scheduling supporting Simulator framework (신경망 기반 적응적 일정계획 지원 시뮬레이터 Framework 연구)

  • Kim, Cheol-Hwan;Jeong, In-Seong;Thapa, Devinder;Wang, Ji-Nam
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.523-527
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    • 2005
  • 현재 기업에서는 생산 효율을 극대화시키기 위하여 많은 비용을 투자하여 Package형태의 솔루션(S/W)을 도입하고 있다. 그러나 솔루션들은 그 특성상 기업특성을 생산 일정계획 수립에 충분히 반영하지 못하고 있어 실제 도입 후에 사용에 어려움이 겪고 있으며 일부 기업에서는 생산일정 전문가를 통하여 재생산계획을 수립하고 있다. 본 연구는 상용화 되고 있는 솔루션에서 제시된 생산일정을 생산일정 전문가가 회사의 특성을 고려하여 재생산일정을 수립하는 단계에 대한 사용자의 패턴을 추출 후 신경망을 통하여 패턴을 학습하여 재생산일정 수립 시 소요되는 시간을 최소화 시키며 기업의 특성을 반영하는 적응적 일정계획 지원 시뮬레이터의Framework을 제시하고자 한다.

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A study of CAD(Computer Aided diagnosis) and CAP(Computer Aided Prediction) Frameworks for high-risk patients in ubiquitous environment using Neural Network (유비쿼터스 환경에서 고위험군 환자의 생체신호를 이용한 실시간 신경망 기반의 질병징후탐지시스템(CAD) 및 예측시스템(CAP)의 프레임웍 연구)

  • Jeong, In-Seong;Kim, Cheol-Hwan;Park, Seung-Chan;Wang, Ji-Nam
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.475-481
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    • 2005
  • 현재 국내외에서는 유비쿼터스에 대한 연구 및 의료도메인에 대한 많은 연구가 진행되고 있다. 그러나 기존의 연구들은 전체적인 시스템에 대한 연구가 대부분이어서 실제 환경을 구축하는데 상당한 어려움이 따르고 있다. 본 연구에서는 위와 같은 문제점을 해결하기 위하여 고위험군 환자를 대상으로 다음과 같은 시나리오를 작성하였다. 시나리오는 Home -medical 서비스, Emergency call center 서비스 그리고 응급차량 서비스로 구성하였다. 본 연구에서는 위와 같은 시나리오를 기반으로 고위험군 환자의 생체 신호를 획득한 후 신경망을 이용하여 생체 신호 데이터를 학습한 후 환자의 이상 징후를 진단하는 CAD시스템의 프레임웍과 환자의 위험 수위를 단계별로 분류하는 알고리즘을 제시한다. 또한 과거의 데이터를 이용하여 미래의 환자상태를 예측하는 CAP시스템의 프레임웍을 제시하고 프레임웍에 대한 타당성을 검증하고자 한다.

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Construction of Korean Korea CALS Standardization (한국적 CALS 표준화 구축방안)

  • 김철환;김규수;신영인
    • The Journal of Society for e-Business Studies
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    • v.1 no.1
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    • pp.117-140
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    • 1996
  • CALS is recognized as a national response to the new chapter of information society. It is essential that the standardization in Korea should be constructed compatible with not only domestic but also international standardization trend. This study aims to propose a proper direction of CALS standardization in Korea, based on the international CALS standardization movement. This paper classifies standard into five types and provides a proper direction and guidance far each standard. As a trend of CALS standard, all ten data files are converted using SGML standard far the interchangeability of data among heterogenous systems. CAD and Graphic data arc also moving toward to the STEP as their standard. In this regard, this paper discusses how to implement SGML and STEP Model. Finally, this paper proposes a method how to construct an EDI system with CALS standard and how to establish a standard authorization institute which will be responsible far the standard authorization. Furthermore, this paper also proposes the CALS Test Network (CTN) as its experimental method.

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An Advisory Expert System for the Designer of Reinforced Concrete Structures (철근 콘크리트 구조물 설계자를 위한 전문가 시스템 개발)

  • 정영식;김철환
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.04a
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    • pp.372-377
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    • 1995
  • Expert systems which represent the appllication of artificial intelligence research are now nearly 20 years old. It is said that the present technology together with ever- increasing computing applicability of Combined Hypertext-Expert System Techniques to the design of reinforced concrete structures. Hypertext systems allow the user to control the system while expert systems alone don't give the user any control over the system. Therefore the combination of these two techniques, offered by KnowledgePro, may bring us closer to real user-expert communication. The system developed in this work offers information on design in general by reorganizing ACI Manual 318-89, detailed stress analysis and cross sectional design of simple PC/RC beams and optimum design of reinforced concrete building frames. The system also includes the author's earlier work on guidance to identify types of cracks in concrete. It is also includes the author's earlier work on guidance to identify types of cracks in concrete. It is also demonstrated how well and conveniently existing programs can be used by reorganizing the user manuals in the context of hypertext.

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Development of the Algorithm for Discriminating Faults from Variation using Wavelet Transform (웨이블릿 변환을 이용한 고장과 Variation의 유형 구분 알고리즘 개발)

  • Seo, Hun-Chul;Lee, Soon-Jeong;Kim, Chul-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.8
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    • pp.1460-1466
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    • 2011
  • This paper proposes the algorithm for discriminating faults from the variation due to the operation of non-linear components to prevent the mal-operation of protection relay in the distribution system. An IEEE 13 node test feeder is modeled to analyze the characteristics of the fault and each variation using EMTP-RV. Simulations with various operating conditions of transformers, non-linear loads, and unbalanced loads are performed using the test feeder model. Based on simulation results, the wavelet transform is adopted to analyze the current waveforms from the faults and variations to find out the differences between them and the algorithm for discriminating faults from the variation is proposed. The proposed algorithm is verified by using the current waveforms simulated in the KEPCO's distiribution system and IEEE 13 node test feeder.

An Application of Harmony Search Algorithm for Operational Cost Minimization of MicroGrid System (마이크로 그리드 운영비용 최소화를 위한 Harmony Search 알고리즘 응용)

  • Rhee, Sang-Bong;Kim, Kyu-Ho;Kim, Chul-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1287-1293
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    • 2009
  • This paper presents an application of Harmony Search (HM) meta-heuristic optimization algorithm for optimal operation of microgrid system. The microgrid system considered in this paper consists of a wind turbine, a diesel generator, and a fuel cell. An one day load profile which divided 20 minute data and wind resource for wind turbine generator were used for the study. In optimization, the HS algorithm is used for solving the problem of microgrid system operation which a various generation resources are available to meet the customer load demand with minimum operating cost. The application of HS algorithm to optimal operation of microgrid proves its effectiveness to determine optimally the generating resources without any differences of load mismatch and having its nature of fast convergency time as compared to other optimization method.

A Study on the Effects of Neutral Current by Unbalanced Load in Two Step Type Pole using KEPCO's Distribution System (한전 배전 계통을 이용한 2단장주의 불평형 부하에 따른 중성선 전류의 영향에 관한 연구)

  • Park, K.W.;Seo, H.C.;Kim, C.H.;Jung, C.S.;Yoo, Y.P.;Lim, Y.H.;Lee, W.J.
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.3
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    • pp.465-471
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    • 2007
  • The one step type pole and two step type pole are used in KEPCO's distribution system. The neutral current increases in three-phase four-wire distribution system due to unbalanced load. Usually, power line and communication line are installed at contiguity by effect of topography in Korea. To this end, the damages such as electrostatic induction, electromagnetic induction and harmonic induction generated by induced voltage and current are occured in power line and communication line. This paper calculates the neutral current in KEPCO's distribution system using EMTP by composing various simulated conditions. Also, these results are verified by vector analysis.

Modeling of Transformer Inrush Current on Jeju Power System using EMTP (EMTP를 이용한 제주계통의 여자돌입전류 모델링)

  • Seo, H.C.;Yeo, S.M.;Kim, C.H.;Lyu, Y.S.;Cho, B.S.
    • Proceedings of the KIEE Conference
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    • 2007.11b
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    • pp.95-97
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    • 2007
  • Transformer inrush current can cause the voltage drop by source impedance. The accurate modeling and analysis for inrush current is first step to limit the inrush current and improve the power qualify. This paper presents the modeling of transformer inrush current by EMTP-RV using Jeju power system, Korea. The method to model the hysteresis curve of transformer in EMTP-RV is discussed. Simulations demonstrate the verification of modeling of inrush current by comparing the data recorded in field with simulation values and analyzing the harmonics of inrush current.

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A Characteristic Analysis of Superconducting Fault Current Limiter in Power Systems (초전도 한류기 동작 특성에 따른 계통 영향 분석)

  • Rhee, Sang-Bong;Kim, Chul-Hwan;Kim, Kyu-Ho;Hyun, Ok-Bae
    • Proceedings of the KIEE Conference
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    • 2007.11b
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    • pp.207-209
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    • 2007
  • For proper application of the superconducting fault current limiter(SFCL), the prior investigation of fundamental characteristics and its effects to the distribution systems are needed. The Current limiting behavior of SFCL is dominated by quenching and recovery characteristics. So, we have developed an EMTP/ATPDraw model of resistive type SCFL using MODELS language. The operating characteristics and current limiting behaviors of SFCL in distribution systems have been simulated and investigated.

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A Study on Harmonic Analysis in Grid-Connected Photovoltaic System using EMTP (EMTP를 이용한 태앙광 발전의 계통 연계시 고조파 분석에 관한 연구)

  • Ko, Yun-Tae;Seo, Hun-Chul;Yeo, Sang-Min;Kim, Chul-Hwan
    • Proceedings of the KIEE Conference
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    • 2008.11a
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    • pp.232-234
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    • 2008
  • 태양광 발전은 영구적이고 친환경적인 에너지를 생산하는 에너지원으로서 세계적인 관심을 받고 있으며 앞으로도 더 많은 투자와 연구가 진행될 것으로 예상된다. 이러한 태양광 발전이 계통에 연계되었을 때 전력품질, 보호 등 다양한 문제에 영향을 끼친다. 특히, 태양광의 출력을 직류에서 교류로 변환하는 인버터의 스위칭으로 인하여 많은 고조파가 발생하게 된다. 따라서, 태양광 발전의 계통 연계시 발생하는 고조파의 분석은 반드시 필요한 사항이다. 본 논문에서는 태양광 발전의 계통 연계시 고조파 분석을 수행하였다. 태양광 발전은 EMTP를 이용하여 단상 풀 브릿지 인버터를 이용하여 계통에 연결되는 것으로 모델링 하였다. 태양광 발전의 용량 및 비선형 부하의 용량을 다양하게 변화시켜 모의 하였으며, 다양한 조건에 따라 부하에 흐르는 전류의 THD의 변화를 분석하였다.

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