• 제목/요약/키워드: Improving System

검색결과 7,396건 처리시간 0.031초

전력계통 안정도 향상을 위한 STATCOM 안정화 장치 설계 (Design of STATCOM Stabiliser for Improving Power System Stability)

  • 이석오;정영민;문경준;황기현;박준호;이정관
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 A
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    • pp.149-151
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    • 2001
  • This paper proposes the design of STATCOM(static synchronous compensator) stabilizer for improving power system stability using fuzzy logic controller(FLC). The STATCOM DC voltage regulator contributes negative damping to the power system as the installation of STATCOM DC voltage regulator. STATCOM stabiliser is superimposed on the AC voltage regulator to compensate the negative damping effect. To evaluate usefulness of the proposed method, we perform the nonlinear simulation on a single-machine infinite bus system. As results of the simulations, the proposed method shows better control performance than PI controller in terms of damping effects.

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선박의 횡동요 저감장치를 위한 제어로직 설계 (Control Logic Design for Mass Driving Anti-Rolling System of Ships)

  • 문석준
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.725-731
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    • 2003
  • Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-.oiling system (MD-ARS) might be one candidate of several systems against the ship's rolling. As the movable range of the mass on the ship is finite, the control system must include restriction on the mass position to protect the device and the ship. This restriction usually causes windup phenomenon and control performance is deteriorated seriously. We adopt anti-windup technique to improve the control performance and demonstrate its efficiency by simulation.

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청소년 상담사례 검색 시스템에 관한 연구 (Research of a Counselling Cases Search System for Student-Counselling)

  • 이지현;장혜숙;박기홍
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2002년도 추계종합학술대회
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    • pp.632-635
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    • 2002
  • 본 연구는 학교에서 얻어지는 교사들의 경험을 바탕으로 인터넷을 통한 학생상담의 효율성 증대를 위한 상담 사례 검색 시스템을 구축하는데 있다. 이 시스템은 관리자 모듈과 사용자 모듈로 구성되어 있다. 사용자 모듈은 상담사례 검색 및 입력, 게시판, 자료실 등을 이용할 수 있게 되어 있으며, 관리자 모듈은 자료 관리와 회원 관리 기능을 제공한다. 본 상담사례 검색 시스템은 학생 상담의 성공 확률을 증대시킬 수 있다. 교사가 인터넷을 이용하여 그들의 상담사례를 원격지에서도 쉽게 공유할 수 있기 때문이다.

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교환시스템의 서비스 품절수준 향상을 위한 소프트웨어 블록의 중요도 결정 (Determination of Importance of Software Blocks for Improving Quality of Service in Switching System)

  • 조재균
    • 한국정보시스템학회지:정보시스템연구
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    • 제8권1호
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    • pp.93-108
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    • 1999
  • The switching system is designed and developed to satisfy the performance design objectives recommended by ITU for call processing capacity and quality of service(QOS), etc. When the results by actual measurement at the system testing phase do not satisfy the performance design objectives, however, an effort is required to improve the performance. This paper presents a method for improving QOS by modifying the application programs for the switching system. In the proposed method, the sequence chart related to a delay time for call connection is modelled using PERT(Program Evaluation and Review Technique) network. Then, the criticality index of a message is calculated using Monte Carlo simulation to evaluate which message's processing time to decrease in order to decrease the delay time and thus to improve QOS. The criticality index of a block is also calculated to identify those software blocks that significantly contribute to the delay time.

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한부모가족을 위한 교육 및 상담 활성화 방안 및 효율적 정보전달체계 연구 (Developmental Alternatives and Effective Information Service System of Education and Counseling for Single-Parent Families)

  • 김경신
    • 대한가정학회지
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    • 제41권7호
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    • pp.73-89
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    • 2003
  • The purposes of this research were to investigate the conditions of education and counseling for single-parent families and to propose developmental alternatives and effective information service system. For these objectives, the concurrent-type program for single-parent families that emphasized communication skills, psychological strategies, and the importance of family relationships was constructed. The effectiveness of the program was evaluated by pre-, post test through 163 single parents and their children and it was analyzed by paired t-test. The results suggested that the program was effective in improving self-esteem, satisfaction of life and communication. Several programs for single-parent families using on-line or off-line were analyzed and more effective alternatives were proposed. For improving of wellbeing of single-parent families, the welfare system must be changed to cooperation with other institutions and systematic information service network.

직류전철용 에너지 회생장치 성능개선 (Improving the capability of energy regeneration inverter for dc electric traction system)

  • 방효진;김용기;장수진;송상훈;안규복;원충연
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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    • pp.104-109
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    • 2004
  • Recently, when electric traction system used DC 1500[Vdc] runs on decline of rail road track and slows down, dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. Therefore this paper proposes that the extra power is regenerated through regeneration inverter to AC utility in result this system obstruct to go beyond regular voltage and improve the efficiency. In addition, electric traction system products harmonic current and voltage distortion and reactive power because power converter is used so regeneration inverter normally runs such as active power filter(APF) for improving power quality.

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Post-processing Technique for Improving the Odor-identification Performance based on E-Nose System

  • Byun, Hyung-Gi
    • 센서학회지
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    • 제24권6호
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    • pp.368-372
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    • 2015
  • In this paper, we proposed a post-processing technique for improving classification performance of electronic nose (E-Nose) system which may be occurred drift signals from sensor array. An adaptive radial basis function network using stochastic gradient (SG) and singular value decomposition (SVD) is applied to process signals from sensor array. Due to drift from sensor's aging and poisoning problems, the final classification results may be showed bias and fluctuations. The predicted classification results with drift are quantized to determine which identification level each class is on. To mitigate sharp fluctuations moving-averaging (MA) technique is applied to quantized identification results. Finally, quantization and some edge correction process are used to decide levels of the fluctuation-smoothed identification results. The proposed technique has been indicated that E-Nose system was shown correct odor identification results even if drift occurred in sensor array. It has been confirmed throughout the experimental works. The enhancements have produced a very robust odor identification capability which can compensate for decision errors induced from drift effects with sensor array in electronic nose system.

부가질량을 이용한 선박용 횡동요 저감장치에 대한 실험적 연구 (An Experimental Study on Mass Driving Anti-Rolling System for Ships)

  • 문석준;김병인;이성휘;함상용;정종안;이경중
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 추계학술대회논문집
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    • pp.727-730
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    • 2004
  • Reduction of a ship's rolling is the most important performance requirement for improving the safety of the crew on board and preventing damage to cargos as well as improving the comfort of the ride. A mass driving anti-rolling system (MD-ARS) might be one candidate of several systems against the ship's rolling. In this paper, three types of MD-ARS, two passive and one active devices, are developed for small ships. After they are installed on the cabin of the small leisure boat, respectively, a series of test is conducted before and after operating them. Through the test, it is confirmed that the roll responses of the ship are pretty well reduced by the system.

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