• Title/Summary/Keyword: Performance evolution

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A Study on the Wheel Wear of High Speed Train Running on the Conventional Line (경부고속열차의 기존선 주행시 차륜마멸특성에 관한 연구)

  • 강부병;이희성
    • Tribology and Lubricants
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    • v.19 no.4
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    • pp.187-194
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    • 2003
  • This paper describes the characteristics of wheel wear of high speed train running on the conventional line. Conventional line has many curved tracks that cause severe wheel flange wear. The influences of lubrication, cant deficiency, curve radius on wheel wear are also described considering the operation performance of the highspeed trainset. A method of calculation using contact patch work model is presented for determination of the evolution by wear of railway wheels.

Graceful Degradation FEC Layer for Multimedia Broadcast/Multicast Service in LTE Mobile Systems

  • Won, Seok Ho
    • ETRI Journal
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    • v.35 no.6
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    • pp.1068-1074
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    • 2013
  • This paper proposes an additional forward error correction (FEC) layer to compensate for the defectiveness inherent in the conventional FEC layer in the Long Term Evolution specifications. The proposed additional layer is called a graceful degradation (GD)-FEC layer and maintains desirable service quality even under burst data loss conditions of a few seconds. This paper also proposes a non-delayed decoding (NDD)-GD-FEC layer that is inherent in the decoding process. Computer simulations and device-based tests show a better loss recovery performance with a negligible increase in CPU utilization and occupied memory size.

The Improvement of Welding Quality of Spot Welder Via an Instantaneous Power Contorl (순시전력 제어를 통한 스폿용접기의 용접품질 향상)

  • 김재문;원충연;최규하;김규식;목형수
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.558-562
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    • 1999
  • In this paper, the inverter spot welding system with high efficiency via an instantaneous power control is presented. In spot welding, instantaneous power control is utilized in order to attain less spatter and high welding performance. Also we proposed a PI controller for spot welder system using Evolution Strategy(ES) with varying search space. ES with varying search space which depends on fitness values at each generation is used to tune PI control parameters

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Automatic synthesis of heat exchanger networks (열교환기 네트워크의 자동합성)

  • 오전근;김경미;윤인섭
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.613-618
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    • 1986
  • In this study a s/w system(HENSPIN) for the automatic synthesis of HEN(heat exchanger network) was developed based on Pinch Design Method. The synthesized HEN by HENSPIN are satisfying performance targets such as minimum utility usage with as few as possible capital items. The invented network is near optimal in capital and operating cost. It will be used as initial structure for evolution to the structure which has optimal operability.

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Review of Color CRT Electron Gun Design Trends and the CRT Industry Surviving Strategy

  • Chen, Hsing-Yao
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.1059-1063
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    • 2002
  • The evolution of color CRT electron gun design over the past 40 years is addressed. Many milestones of CRT E-gun design are cited. For the future survival of color CRT the multi-beam group color E-gun and the recently announced multi-beam type index gun are suggested as the answer to the challenge of the next generation's requirements of low power and high performance color CRT

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Development and Implementation of Brushless DC Motor Controlles Based on Inteligent Control

  • Park, Jin-Hyun;Park, Young-Kiu
    • Journal of Electrical Engineering and information Science
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    • v.2 no.3
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    • pp.61-65
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    • 1997
  • This paper proposes an intelligent controller for brushless DC motor and load with unknown nonlinear dynamics. The proposed intelligent control system consists of a plant identifier and PID controller with varying gains. The identifier is constructed using an Auto Regressive Moving Average (ARMA) model. In order to tune the parameters of the identifier and the gains of the PID controller efficiently, e also propose a modified Evolution Strategy. Experimental results show that the proposed intelligent controller for brushless DC motor has good control performance under unknown disturbance.

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Optimal Design of Arrayed Waveguide Grating

  • Jung, Jae-Hoon
    • Journal of the Optical Society of Korea
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    • v.8 no.3
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    • pp.99-103
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    • 2004
  • This paper describes the optimal design of an AWG spectrum to meet various specifications and improve some physical parameters. The objective function is the norm of the difference between design parameters and target values. To obtain the design parameters, the Fourier model is employed and the design variables arc spacing of array waveguide, width of array waveguide, optical path difference, and focal length. The (1+1) Evolution Strategy is employed as the optimization tool. The optimization procedure is applied to a 16-channel AWG and the optimized design variables will considerably improve the system performance.

The Analysis and Design of Tree-LDPC codes with EXIT charts (EXIT charts를 이용한 Tree-LDPC 코드의 분석 및 설계)

  • Lee, Sung-Jun;Heo, Jun
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.1049-1050
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    • 2006
  • In this paper, we present the analysis of Tree-LDPC codes using EXIT(Extrinsic information transfer) charts methods. Two different EXIT charts schemes are compared. One is based on the closed form equation and the other is based on Monte-Carlo simulation. The thresholds by these two schemes match well with the threshold by DE(density evolution) scheme. Simulation performance is also shown with the obtained thresholds.

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A study on the wheel wear of highspeed train running on the conventional line (경부고속열차의 기존선 주행시 차륜마멸특성에 관한 연구)

  • 강부병;이희성;왕영용
    • Proceedings of the KSR Conference
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    • 2000.05a
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    • pp.135-142
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    • 2000
  • This Paper describes a characteristics of wheel wear of high speed train running on the conventional line. Conventional line has many curved tracks that cause severe wheel flange wear. The influences of lubrication, cant deficiency, owe radius on wheel wear are also described considering the operation performance of the highspeed trainset. A method of calculation using contact patch work model is presented far determination of the evolution by wear of railway wheels.

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Aero Engine in the New Century -Challenge in Technology and Business-

  • Sekido, Toshinori
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.440-448
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    • 2004
  • Toasting the 100 year anniversary of controlled, powered flight, the propulsion system used on today's aircraft represents the evolution of jet propulsion based on the gas turbine, first conceived by Whittle and Von Ohain about 70 years ago. In that period, propulsion system concepts have evolved through turbo-props, turbo-jets, low by-pass ratio(BPR) turbofans to today's high BPR 2-shaft and 3-shaft turbofans. Also, this period has seen remarkable progress in the performance, reliability environmental compatibility of these propulsion systems.(omitted)

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