• 제목/요약/키워드: linearly independent

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민감도 해석 기법을 이용한 베어링 파라미터 규명 (Idetification of Parameter for Bearing Using Sensitivity Analysis Method)

  • 이경백;김영배
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.354-357
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    • 2001
  • The developed method is proposed to identify rotor dynamic parameters. The method known imbalance vector, which renders over-determined linear system equation. The solution of the system equation can be obtained using least square method. The sensitivity analysis is performed to extract optimized solution, which is considered to be insensitive to inherent measurement errors. As an alternative approach to identify the parameters of bearings and rotor, adding a known imbalance to the rotor produces another equation set to make the system equations over-determined and linearly independent.

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원공을 가진 CFRP 복합재료의 피로누적손상 및 피로수명에 대한 확률적 해석 (A Probabilistic Analysis for Fatigue Cumulative Damage and Fatigue Life in CFRP Composites Containing a Circular Hole)

  • 김정규;김도식
    • 대한기계학회논문집
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    • 제19권8호
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    • pp.1915-1926
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    • 1995
  • The Fatigue characteristics of 8-harness satin woven CFRP composites with a circular hole are experimentally investigated under constant amplitude tension-tension loading. It is found in this study that the fatigue damage accumulation behavior is very random and history-independent, and the fatigue cumulative damage is linearly related with the mean number of cycles to a specified damage state. From these results, it is known that the fatigue characteristics of CFRP composites satisfy the basic assumptions of Markov chain theory and the parameter of Markov chain model can be determined only by mean and variance of fatigue lives. The predicted distribution of the fatigue cumulative damage using Markov chain model shows a good agreement with the test results. For the fatigue life distribution, Markov chain model makes similar accuracy to 2-parameter Weibull distribution function.

The Effect of the Number of Training Data on Speech Recognition

  • Lee, Chang-Young
    • The Journal of the Acoustical Society of Korea
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    • 제28권2E호
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    • pp.66-71
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    • 2009
  • In practical applications of speech recognition, one of the fundamental questions might be on the number of training data that should be provided for a specific task. Though plenty of training data would undoubtedly enhance the system performance, we are then faced with the problem of heavy cost. Therefore, it is of crucial importance to determine the least number of training data that will afford a certain level of accuracy. For this purpose, we investigate the effect of the number of training data on the speaker-independent speech recognition of isolated words by using FVQ/HMM. The result showed that the error rate is roughly inversely proportional to the number of training data and grows linearly with the vocabulary size.

원형 CAV 댐퍼의 개발에 관한 연구 (A Study on the Development of a Circular CAV Damper)

  • 권영필
    • 설비공학논문집
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    • 제25권11호
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    • pp.612-616
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    • 2013
  • A circular CAV damper has been developed, based on the investigation of the pressure loss, and the flow-resisting moment by the damper blade. When a torsional spring is attached to the damper axle, and the setting angle is adjusted to around $82^{\circ}$, the volume rate across the damper is almost independent of the static pressure. Such a CAV characteristic appears at an opening angle between $40^{\circ}$ and $60^{\circ}$, where the normalized moment decreases linearly with the angle. In addition, by adjusting the setting angle, the volume rate can be controlled to within 10% error, regardless of the pressure loss.

에너지저장요소를 사용하지 않는 전력보상기에 의한 중성선 전류의 제거 (Eliminating the Neutral Current by the Power Compensator without using Energy Storage Elements)

  • 김효성
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제48권6호
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    • pp.330-335
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    • 1999
  • This paper proposed the p-q-r coordinate system where the instantaneous active power p, and the two instantaneous reactive powers qq, qr were defined. The three power components are linearly independent, so the compensation for the two instantaneous reactive powers leads to control the two components of the current space vector. With the theory, the neutral current of a three-phase four-wire system can be eliminated by only compensating the instantaneous reactive power using no energy storge element.

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Optimal System Structure of Linear Consecutive-k-out-of-n:F System

  • Yun, Won-Young;Kim, Gue-Rae;Hisashi Yamamoto
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2004년도 정기학술대회
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    • pp.201-206
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    • 2004
  • The linear consecutive-k-out-of-n:F system consists of n components ordered linearly and fails if and only if at least k consecutive components fail. We assume that the failure times of components are independent and identical exponentially distributed. This paper develops a model to calculate the expected cost per unit time of a linear consecutive-k-out-of-n:F system. The optimization problem to find the system structure parameter k to minimize the expected cost per unit time is considered.

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Effect of Chromium Chloride on the Mechanical and Dielectric Properties of EPDM Rubber

  • Salem, M.A.;Khaled, M.A.;Hussein, A.M.;Elway, E.
    • Macromolecular Research
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    • 제11권4호
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    • pp.256-259
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    • 2003
  • Measurements of Young's modulus, dielectric loss and a.c. conductivity have been carried out on EPDM rubber samples loaded with different concentrations of $CrCl_3$ (0,2,4 and 6 phr). The values of Young's modulus was found to be linearly dependent on the $CrCl_3$ content. Variation of the dielectric loss with temperature showed that $CrCl_3$ may act as plasticizer. However, at higher frequencies the dielectric loss was found to be independent of frequency and the rubber samples may behave as non-polar dielectric. Investigations of the a.c conductivity suggested that the conduction in these rubber samples can be described by small polaron tunneling. In addition, conductivity was found to increase with $CrCl_3$ content.

On the Improved Green Integral Equation applied to the Water-wave Radiation-Diffraction Problem

  • Do-Chun,Hong
    • 대한조선학회지
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    • 제24권1호
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    • pp.1-8
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    • 1987
  • It is shown that irregular frequencies in the source and doublet distribution method, can be eliminated if the Green function associated with Kelvin's source of pulsating strength, is modified only in the region inside the body at the level of the undisturbed free surface. The system of the resulting Green integral equation is augmented without loss of the square-integrable property of its kernel so hat the discretisation yield N linearly independent equations for N unknown variables. From the solution, the potential and velocity at any point on the wetted surface of a surface-piercing body can be found using the properties of the double layer composed of the source and normal doublet distribution.

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고온 평판의 분무냉각에 있어서 MHF점에 관한 연구 (Study on Minimum Heat Flux Point in Spray Cooling of Hot Plate)

  • 김영찬
    • 설비공학논문집
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    • 제13권10호
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    • pp.974-981
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    • 2001
  • In this study, the minimum heat flux conditions are experimentally investigated for the spray cooling of hot plate. The hot plates are cooled down from the initial temperature of about$ 900^{\circ}C$, and the local heat flux and surface temperatures are calculated from the measured temperature-time history. The results show that the minimum heat flux point temperatures increase linearly resulting from the propagation of wetting front with the increase of the distance from the stagnation point of spray flow. However, in the wall region, the minimum heat flux point temperature becomes independent of the distance. Also, the velocity of wetting front increases with the increase of the droplet flow rate.

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냉방부하에 영향을 미치는 외기 환경조건의 상관관계에 관한 연구 (A Study on Correlation of Outdoor Environmental Condition about Cooling Load)

  • 이제묘
    • 설비공학논문집
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    • 제24권11호
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    • pp.759-766
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    • 2012
  • To estimate the cooling load for the following day, outdoor temperature and humidity are needed in hourly base. But the meteorological administration forecasts only maximum and minimum temperature. New methodology is proposed for predicting hourly outdoor temperature and humidity by using the forecasted maximum and minimum temperature. The correlations for normalized outdoor temperature and specific humidity has been derived from the weather data for five years at Seoul, Daejeon and Pusan. The correlations for normalized temperature are independent of date, while the correlations for specific humidity are linearly dependent on date. The predicted results show fairly good agreement with the measured data. The prediction program is also developed for hourly outdoor dry bulb temperature, specific humidity, dew point, relative humidity, enthalpy and specific volume.