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검색결과 296건 처리시간 0.031초

연삭입력조건을 이용한 연속절삭날간격의 예측 (Estimation of the successive cutting point spacing using grinding input conditions)

  • 이영문;손재환;정연철;배대원;손성필
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.227-228
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    • 2006
  • In order to calculate the maximum undeformed chip thickness in grinding operation, it is necessary to estimate the successive cutting point spacing. In the past it is obtained by experiments. In this paper, the average successive cutting point spacing has been estimated using the given grinding input conditions.

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XLPE/EPDM 계면에서의 절연파괴 특성 (Properties of Electrical Breakdown in the Interface between XLPE / EPDM)

  • 조정형;한성구;이창종;김석기;최용식;박강식;서광석;박대희;한상옥
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.1469-1471
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    • 1996
  • In this paper, We intended to evaluate the characteristics of XLPE/EPDM interface which exists in the cable joint. The fault of practical cable was mainly occurred in this interface. Thus we looked into the electrical characteristics through the conduction current and the breakdown test. Through the experiment, we obtained the result that the conduction current in this interface flowed less than other dielectric materials, that the breakdown strength was higher and that the pressure dependance of the breakdown strength was higher.

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케냐프의 물과 효소를 이용한 이중 레팅과 면섬유화에 관한 연구 (The Double Rotting Using Water and Enzyme & Cottonizing of Kenaf)

  • 이미경;이혜자;유혜자;한영숙
    • 한국의류학회지
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    • 제29권7호
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    • pp.938-947
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    • 2005
  • Kenaf basts were double retted by using water and enzyme. The best conditions were enzyme concentration $0.125\%$ and 1 day treatment at $50^{\circ}C$, 4 days treatment at $20^{\circ}C$. It was showed that the double rotting could be more economical and eco-friendly than just water rotting or enzyme rotting. Kenaf fibers have been cottonized by removing lignin and hemicellulose partially. In order to cottonize kenaf fiber, lignin of kenaf fibers were removed by sodium chlorite and then hemicellulose of kenaf fibers were removed by sodium hydroxide. The cottonizing phenomenon of kenaf fibers were was confirmed in transversal and longitudinal photograph of SEM. The tensile strength and crystallinity of cottonized fiber were investigated. The tensile strength and crystallinity were lower as the lignin and hemicellulose of kenaf fibers were less.

유전 알고리즘을 이용한 모듈라 웨이블릿 신경망의 최적 구조 설계 (Optimal Structure of Modular Wavelet Network Using Genetic Algorithm)

  • 서재용;조현찬;김용택;전홍태
    • 전자공학회논문지SC
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    • 제38권5호
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    • pp.7-13
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    • 2001
  • 단일 신경망에 기반한 웨이블릿 이론과 모듈라 개념을 결합하여 기존의 웨이블릿 신경망이나 모듈라 네트워크의 일종인 모듈라 웨이블릿 신경망이 제안되었다. 본 논문에서는 유전 알고리즘을 사용하여 모듈라 웨이블릿 신경망의 최적구조를 효과적으로 설계하는 방법을 제시하였다. 각 모듈을 구성하는 웨이블릿 신경망의 웨이블릿 기저함수의 팽창과 이동계수를 결장하기 위해 유전 알고리즘을 사용하였다. 제안한 최적 구조 설계 알고리즘을 근사화 문제에 적용하여 우수성을 검증하였다.

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케냐프 섬유의 표백에 대한 연구 (제1보) -표백효과를 중심으로- (The Study on Bleaching of Kenaf Fibers (Part I) -Effect of Bleaching-)

  • 장현숙;이혜자;유혜자;한영숙
    • 한국의류학회지
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    • 제29권9_10호
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    • pp.1295-1305
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    • 2005
  • The study was based on a three-stage, non-repetitive factorial experiment in which chemical-rotted kenaf fibers were treated separately with hydrogen peroxide concentrations of $0.5\%,\;1\%\;and\;2\%$, with pH solutions of 7, 9 and 11, and treatment times of 30, 60 and 90 minutes. Under optimal conditions, the study was conducted to determine the bleaching efficiency by the addition of chelators, penetrants and surfactants. The bleaching effects on the kenaf fibers were high in high hydrogen peroxide concentration, high in alkali solution pH, low in long treatment time. The optimal level of hydrogen peroxide on bleaching effects were at $2\%$ hydrogen peroxide concentration, with pH of 11 and treatment time of 60 minutes. Under the conditions of $2\%$ hydrogen peroxide concentration, pH 11 and treatment time of 60 minutes, the addition of chelator: Sodim Pyrophosphate(SP), Citric Acid(CA) made the bleaching effects of the kenaf fibers high.

시간-주파수 분석을 이용한 모듈라 웨이블렛 신경망의 최적 구조 설계 (On Designing Optimal Structure of Modular Wavelet Neural Network with Time-Frequency Analysis)

  • 서재용;김용택;조현찬;전홍태
    • 전자공학회논문지SC
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    • 제38권2호
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    • pp.12-19
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    • 2001
  • 본 논문에서는 새로운 구조의 모듈라 시스템의 최적구조 설계 알고리즘을 제안하였다. 모듈라 시스템은 구조의 단순화와 시간 주파수 분석법을 이용하기 위해 웨이블렛 신경망으로 구성하였다. 제안한 최적구조 설계 알고리즘을 이용하여 근사화 대상함수의 시간-주파수 특성을 분석하여 모듈의 개수와 부-시스템의 노드의 개수를 결정할 수 있다. 제안한 최적 구조 설계 알고리즘은 시스템의 특성을 분석하여 모듈라 웨이블렛 신경망의 최적구조를 설계할 수 있는 방법론을 제공할 수 있다. 제안한 새로운 구조와 최적 구조 설계 알고리즘을 근사화 문제에 적용하여 우수성을 검증하였다.

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운동오차 예측을 위한 공작기계 스핀들용 유도전동기의 발열량 해석 (Thermal Characteristic Analysis of Induction Motors for Machine Tool Spindle for Motion Error Prediction)

  • 성기현;조한욱;황주호;심종엽
    • 한국정밀공학회지
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    • 제32권2호
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    • pp.141-147
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    • 2015
  • This paper deals with thermal characteristic analysis of induction motors for machine tool spindle for motion error prediction. Firstly, the inverse design of general induction motors for machine tool spindle has been performed by design principles. Characteristics considering VVVF inverter of induction motors were analyzed. Secondary, power loss and thermal characteristics of induction motors analyzed by equivalent thermal resistance model from Motor-CAD S/W. To develop a second-order fitted power-loss distribution model for the constant-torque operating range of the induction motor, we employed the design of experiment and response surface methodology techniques. Finally, the analysis results were experimentally verified, and the validity of the proposed analysis method was confirmed.

철심형 이동자와 고정자의 형상에 따른 영구자석 선형 동기전동기의 전자기력 특성 비교 및 피칭 모멘트 실험 (Comparison of Electromagnetic Force Characteristics and Experiment of Pitching Moment in Permanent Magnet Linear Synchronous Motor According to the Moving Iron Core and Stator Topology)

  • 이승한;조한욱;김경호;오정석
    • 전기학회논문지
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    • 제64권12호
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    • pp.1695-1702
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    • 2015
  • This paper presents the characteristic analysis and experiment of force characteristics in permanent magnet linear synchronous motor for accuracy prediction of linear motion machine tools. In particular, the pitching moment resulting from attraction force ripple has been analysed and tested. Firstly, we analysed the characteristics of detent force, attraction force, and pitching moment in permanent magnet linear synchronous motor according to the design techniques such as auxiliary teeth, chamfering, and permanent magnet skewing. In addition, we suggested the experimental set for measurement of pitching moment. Finally, the results from measurement shows the good agreement with those obtained from finite element analysis results.