• 제목/요약/키워드: Generation Gap

검색결과 447건 처리시간 0.027초

A study of selection operator using distance information between individuals in genetic algorithm

  • Ito, Minoru;Sugisaka, Masanori
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1521-1524
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    • 2003
  • In this paper, we propose a "Distance Correlation Selection operator (DCS)" as a new selection operator. For Genetic Algorithm (GA), many improvements have been proposed. The MGG (Minimal Generation Gap) model proposed by Satoh et.al. shows good performance. The MGG model has all advantages of conventional models and the ability of avoiding the premature convergence and suppressing the evolutionary stagnation. The proposed method is an extension of selection operator in the original MGG model. Generally, GA has two types of selection operators, one is "selection for reproduction", and the other is "selection for survival"; the former is for crossover and the latter is the individuals which survive to the next generation. The proposed method is an extension of the former. The proposed method utilizes distance information between individuals. From this extension, the proposed method aims to expand a search area and improve ability to search solution. The performance of the proposed method is examined with several standard test functions. The experimental results show good performance better than the original MGG model.

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중첩방전에 의한 오존생성 특성 (Fundamental Investigation Results on Ozone Generation Characteristics by Superimposed Discharge)

  • 안희성;;위상봉
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권2호
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    • pp.91-97
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    • 2003
  • In addition to its strong oxidizing power, the ozone has definite advantages over other commercial oxidants, namely, no undesirable by- products or residues are formed. With growing interest in the improvement of the ozone production in the industrial fields, many types of ozonizer using the electrical discharges have been proposed for the higher efficiency and the higher Performance at atmospheric Pressure. Among them, a superposition of different type discharges has been proposed. Especially, since the improvement for the low efficiency of dc discharge and narrow gap of surface discharge is required, a do and an at voltage are applied to same reaction space (or volume) to increase energy density at the same space. An investigation was focused on the superposition with a dc (streamer) corona and 3 surface discharge. This paper describes the investigation results on fundamental ozone generation characteristics by this superimposed discharge.

차세대 파워디바이스 SiC/GaN의 산업화 및 학술연구동향 (Commercialization and Research Trends of Next Generation Power Devices SiC/GaN)

  • 조만;구영덕
    • 에너지공학
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    • 제22권1호
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    • pp.58-81
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    • 2013
  • 탄화규소(SiC)나 질화갈륨(GaN)과 와이드갭 반도체를 이용한 전력소자의 생산기술이 크게 발전하여 그간 널리 사용되어 온 실리콘(Si) 전력소자와 비교하여 작동전압, 스위칭 속도 및 on-저항 등이 크게 향상되어 몇 개 기업은 제품화를 시작하였다. 내압 등 기술적 과제 등을극복하여 산업화를 하고자하는 움직임을 소개하고 아울러 연구동향도 분석한다.

직류 열 플라즈마의 발생및 그 특성에 관한 연구 (A Study On D.C. Thermal Plasma Generation And Its Characteristics)

  • 김원규;연충규;김준식;황기웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1989년도 하계종합학술대회 논문집
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    • pp.451-454
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    • 1989
  • A DC thermal plasma generation system for both LPPS and APPS was designed and its characteristics was analysed. Discharge experiments for 60 conical and cylindrical type anode nozzle were conducted and the results were compaerd each other. The flow dependence and the electrode gap dependence were precisely explained and especially voltage jump phenomena under the existance of the parallel magnetic field was studid.

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그리스윤활 고속주축의 예압과 냉각조건에 따른 열특성의 실험적 고찰 (Experimental study on the thermal charateristics according to the pre-load and cooling condition for the high speed spindle with grease lubrication)

  • 최대봉;김수태;정성훈;김용기
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 추계학술대회
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    • pp.41-46
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    • 2003
  • The important problem in high speed spindles is to reduce and minimize the thermal effect by motor and bail bearings. Thermal characteristics according to the bearing pre-load and cooling condition are studied for the test spindl with grease lubrication and high frequency motor. Bearing and motor we main heat generation, and heat generation by ball bearings as a function of load, viscosity and gyroscopic moment effect are considered. Temperature distribution and thermal displacement according to the speed of spindle are measured by thermocouple and gap sensor. The results show that the fitting pre-load and cooling temperature are very effective to minimize the thermal effect by motor an ball bearings.

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5 nm 급 반도체 배선 공정 기술 개발 (Development of Interconnect Process Technology for 5 nm Technology Nodes)

  • 최은미;표성규
    • 마이크로전자및패키징학회지
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    • 제23권4호
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    • pp.25-29
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    • 2016
  • The semiconductor industry has been developed mainly by micronization process due to many advantages of miniaturization of devices. Mass production of semiconductors of 10 nm class has been started recently, and it is expected that the technology generation of 5 nm & 7 nm technology will come. However, excessive linewidth reduction affects physical limits and device reliability. To solve these problems, new process technology development and new concept devices are being studied. In this review, we introduce the next generation technology and introduce the advanced research for the new concept device.

조력발전용 수차발전기의 기동·정지시스템에 관한 연구 (A Study on Start·Stop System at Water Turbine-Generator for Tidal Power Plant)

  • 오민환;박철원
    • 전기학회논문지P
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    • 제63권2호
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    • pp.113-118
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    • 2014
  • Tidal power is one of new and renewable energy sources. Tidal power is generated by using the gap in the water level between the water outside and inside the embankment. All tidal power plant in Korea were being operated by import of turn-key from abroad. The know-how and technology which are the most important to build predictive control system has become increasingly difficult to obtain from advanced countries because most of them avoid to transfer, which the domestic development of the control system is needed. In this paper, a study on start stop system at water turbine-generator for tidal power plant at the beginning of development was presented. For improvement the efficiency and develope of core technology of the start stop system, the technique and characteristics of tidal power, modeling, maximum generation calculation method, and optimal control of joint control system in Sihwa tidal power plant were studied.

오일미스트윤활 고속주축의 예압과 냉각에 따른 열특성의 실험적 고찰 (Experimental study on the thermal characteristics according to the preload and cooling for the high speed spindle with oil mist lubrication)

  • 김수태;최대봉;정성훈;김용기
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 추계학술대회 논문집
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    • pp.428-432
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    • 2004
  • The important problem in the high speed spindles is to reduce and minimize the thermal effect by the motor and ball bearings. Thermal characteristics according to the bearing preload and hollow shaft cooling are studied for the test spindle with the oil mist lubrication and high frequency motor. Bearings and motor e main heat generation, and heat generation by ball bearings as a function of load, viscosity and gyroscopic moment effect are considered. Temperature distribution and thermal displacement according to the speed of spindle are measured by thermocouple and gap sensor. The results show that the fitting preload and hollow haft cooling are very effective to minimize the thermal effect by the motor and ball bearings.

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A Study of On-line Monitoring System for a KEPCO Pumped Storage Generator/Motor

  • Kim Hee-Dong;Ju Young-Ho;Kim Yong-Joo;Cho Kyu-Bock
    • Transactions on Electrical and Electronic Materials
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    • 제7권2호
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    • pp.90-95
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    • 2006
  • An on-line diagnostic test has been studied and performed for the pumped storage generator/motor. This study aims at reducing the diagnostic cost, minimizing the technical dependency on third party manufactures. Further design of on-line diagnostic system such as shorted-turn of rotor winding, partial discharge (PD) of stator winding and air-gap between stator and rotor for pumped storage generator/motor has been verified. In addition, it needs to be validated on site performance of the developed continuous on-line monitoring system for corresponding tasks for the improvement of the availability & reliability during operation.

고속열차의 차간 공간에 의해 발생하는 실내소음 특성 분석 (Noise generated from the inter-coach spacing of a high-speed train)

  • 최성훈;박준홍;박찬경
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.1449-1452
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    • 2006
  • When fluid at high speed flows over an open cavity, large acoustic pressure fields inside the cavity are produced by fluid/structure interactions at the downstream end of the cavity. The inter-coach spacing is one of the most important sources of the aero-acoustic noise of a high-speed train. This noise can usually be heard as low frequency structure-borne noise inside the train. In this study experiments were performed in order to investigate the effects of mud-flap length on the aeroacoustic noise generation inside high-speed trains. Results of the measurement confirmed that the characteristics of the noise generated from the inter-coach spacing are strongly dependent on the size of the gap. Also investigated are the characteristics of the turbulent flow after the inter-coach spacing and consequent generation of the aeroacoustic noise inside the cabin.

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