• 제목/요약/키워드: Performance Evaluations

검색결과 888건 처리시간 0.029초

유한요소법과 프라이자흐 모델이 결합된 해석기법을 이용한 극 변환 메모리모터의 동특성해석 (Characteristics Analysis in A Pole Changing Memory Motor Using Coupled FEM & Preisach Modeling)

  • 이승철;이중호
    • 전기학회논문지
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    • 제60권5호
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    • pp.965-970
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    • 2011
  • This paper deals with the PM performance evaluations in a pole changing memory motor (PCMM) using a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the characteristics evaluation relative to magnetizing direction and the pole number of machine on re-demagnetization condition in a pole changing memory motor.

졸리움의 진단과 치료 (Diagnosis and Treatment of Sleepiness)

  • 신재공
    • 수면정신생리
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    • 제10권1호
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    • pp.12-19
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    • 2003
  • Sleepiness, or hypersomnia, is a relatively common complaint and one of the main problems of modern society. Accurate evaluation and diagnosis of sleepiness are important. The methods used for evaluating sleepiness are subjective measures or self-evaluations, performance decrease measures, sleep propensity measures, and arousal decrease measures. A clear and detailed history is important in differential diagnosis of sleepiness because symptoms of sleepiness may be expressed in terms of 'tiredness' or 'fatigue' that do not directly denote sleepiness. Comprehensive diagnostic evaluation is also invaluable because these symptoms may result from a variety of causes ranging from medical disorders to insufficient nocturnal sleep.

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진동특성을 고려한 공작기계 고속주축 개발 (Development of High Speed Machine Tool Spindle Regarding Vibration Characteristics)

  • 박보용
    • 한국정밀공학회지
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    • 제9권3호
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    • pp.149-156
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    • 1992
  • A method for designing high speed spindle is presented in order to enhance the machining accuracy in consideration of vibration characteristics. Experimetal evaluations of the spindle HS 430 as a prototype are made efficiently with the help of bending vibration modes for nonrotational and rotationalstate comparing with the commercial spindle V430. As a result the spindle of HS 430 shows the superior performance than that of V 430.

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보호도지수에의한 전력계통보호시스템 평가 (Performance Evaluations of Protection Systems Using Protectability Indices)

  • 김필석;강상희;이승재;박종국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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    • pp.200-202
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    • 1997
  • 배전계통의 보호능력을 평가하는 방안을 제시한다. 보호관점에서 계통이 가지는 상태를 하고 주어진 계통이 어떤 상태인지를 평가하기 위해 보호기기감도, 보호기기 동작시간차이, 지락저항감지 능력, 기기보호여부, 후비보호구간의 크기의 5가지 요소를 종합적으로 고려 는 지수인 보호도(Protectability)를 제시한다.

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Magnetization Characteristics Analysis in a Pole Changing Memory Motor Using Coupled FEM and Preisach Modeling

  • Lee, Jung-Ho;Lee, Seung-Chul
    • Journal of Magnetics
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    • 제16권4호
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    • pp.386-390
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    • 2011
  • This paper deals with the magnetic equivalent circuit modeling and permanent magnet (PM) performance evaluations of a pole changing memory motor (PCMM). We use a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of the permanent magnets. The focus of this paper is on the evaluation of characteristics such as the magnetizing direction and the pole number of the machine under re- and de-magnetization conditions.

부분흡입노즐방식의 터빈시스템에 대한 성능 평가 (Performance Evaluations for the Partial-Admission Type Turbine System)

  • 홍창욱;박승경;남궁혁준;김경호;김영수;우유철
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2001년도 제17회 학술발표회 논문초록집
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    • pp.11-14
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    • 2001
  • 3-D compressible flow analysis was conducted by using mixing plane method for turbine system which is consisted of partial admission nozzle and rotor. Computational results are shown oblique shock wave in blade leading and trailing edge and also shown flow separation along suction surface of blade due to abrupt blade curvature. But computational results are well agree with 1-D calculation results and experimental data.

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내부 구속 중공 CFT 교각의 연성도 평가 (Ductility Evaluations of Internally Confined Hollow CFT Column)

  • 김현종;염응준;한택희;강영종
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.683-687
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    • 2007
  • Internally Confined Hollow-Concrete Filled Tube(ICH-CFT) column which has two tubes on both side of concrete, inner tube and outer tube perform great seismic abilities, ductility and absorption of energy, by the tubes and the hollow pmt. So this study does qualitative analysis about seismic capacities depending on parameters diameter of column, hollow ratio, thickness of tubes - by moment-curvature analysis.

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자세의 유지성 및 안정성에 관한 해석 (Identification of postural steadiness and stability: state-of-the-art)

  • 정병용;박경수
    • 대한인간공학회지
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    • 제15권1호
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    • pp.53-67
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    • 1996
  • Since Romberg's test in 1953, the analysis of postural sway during upright stance has been widely used as a tool for evaluating balance and disorders of the postural control system. This review describes the methods that have been used to evaluste the static and dynamic performance of the postural control system. Various identification methods of postural control system based on standing balance are discussed and measures of postural sway are described. The application areas of standign balance research, with an emphasis on postural control evaluations, are also briefly described. This review can be used to gain an understanding of the dynamics of human standing balance.

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데스크톱 건성 방전가공 시스템의 개발 및 실험적 성능평가 (Development of Desktop Dry Electrical Discharge Machining (EDM) System and Experimental Performance Evaluations)

  • 이상원;오영석;안수홍
    • 한국정밀공학회지
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    • 제27권1호
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    • pp.119-124
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    • 2010
  • This paper addresses the design and fabrication of desktop die-sinking dry electrical discharge machining (EDM) system and its experimental performance analysis. The developed desktop dry EDM machine has the horizontal configuration with the size of $300{\times}200{\times}260mm$. The experimental performance analysis is conducted to investigate the effects of EDM conditions and dielectric gas temperature on the surface roughness of EDMed slots and number of EDM sparks. The experimental results demonstrate that low feed rate and large electrode displacement are good for better surface roughness and more number of EDM sparks. In addition, low temperature of dielectric gas results in better surface roughness.

제진장치 설치 해양구조물의 생애주기 지진위험도 (Lifetime Seismic Risk of Offshore Structures with a Built-in Vibration Control Device)

  • 김동현
    • 한국해양공학회지
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    • 제24권5호
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    • pp.48-54
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    • 2010
  • The analysis of the seismic risk of an offshore structure with a control device is presented. First, a probability density function was developed to represent seismic hazard, and seismic fragility under artificial earthquake conditions was determined. Fragility curves for an offshore structure with both passive and active control devices were determined. Displacement criteria were set to evaluate the performance of the structure. Based on numerical analysis, the seismic risk to the structure was considerably reduced when the structure had a seismic control device. The seismic risk to the actively controlled structure was decreased by 80% compared to the uncontrolled case. Reasonable performance evaluations of offshore structure with control devices can be conducted through risk analysis.