• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1518-1520
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• 2002

Purpose of this research compares best transfer speed about applied frequency and voltage using characteristic of $L_1-B_4$ mode and $L_1-B_8$ mode linear ultrasonic motor that use piezoelectric effect. By method of study, analyzed best transfer speed measuring and comparison load status that use actuality telephone card in $L_1-B_4$ mode linear ultrasonic motor and no-load status of $L_1-B_8$ mode linear ultrasonic motor. Experiment result is applied frequency(58.4Hz) in $L_1-B_4$ mode linear ultrasonic motor (load state) and the best transfer speed by 19.8[cm/s] at applied voltage(56V) point. Also, $L_1-B_8$ mode linear ultrasonic motor (no-load state) is best transfer speed by applied frequency(27.9kHz) and 32.96[cm/s] at applied voltage (50V) point.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.367-372
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• 2006

선형모터의 설계에 있어서 열적 거동의 파악은 모터의 연속 추력 및 열변형과 관련하여 중요한 고려요소 중의 하나이다. 본 연구에서는 항만자동화를 위한 차세대 컨테이너의 수평이송시스템인 LMTT(Linear Motor-based Transfer Technology)용 선형모터의 설계를 위해 고정자의 코일에서 발생되는 열에 의한 이동체의 온도분포를 분석하여 고정자 모듈의 열해석을 고려한 이동체의 구조설계에 관한 연구를 수행하였다. 먼저, 선형모터의 주요부품의 치수를 설계하고, 다음으로 고정자 모듈의 발열을 고려한 이동체의 온도분포를 분석하여 열-구조 연성해석을 수행하였다.

• 문화기술의 융합
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• 제10권3호
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• pp.801-807
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• 2024

선형 로봇은 자동화 시스템에서 부품의 이송이나 위치 결정에 널리 사용되며 보통 높은 정밀도가 요구된다. 선형 로봇을 응용한 시스템의 제작회사에서는 로봇의 이상 유무를 작업자가 판단하는데, 작업자의 숙련도에 따라 이상 상태를 판단하는 정확도가 달라진다. 최근에는 인공지능 등의 기술을 사용하여 로봇 스스로 이상을 검출하는 방법에 관한 연구가 진행되고 있다. 본 논문에서는 전이 학습을 이용하여 선형 로봇의 볼 스크류 정렬 이상과 선형 레일 정렬 이상을 검출하는 시스템을 제안하고 가속도 센서와 토크 센서 정보를 이용한 별개의 실험을 통해 제안한 시스템의 이상 검출 성능을 검증 및 비교한다. 센서로부터 얻어진 신호를 스펙트로그램 이미지로 변환한 후, 영상 인식 인공지능 분류기를 사용하여 이상의 종류를 진단하였다. 제안한 방법은 선형 로봇뿐만 아니라 일반적인 산업용 로봇에도 적용할 수 있을 것으로 기대한다.

• 한국자동차공학회논문집
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• 제5권1호
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• pp.49-58
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• 1997

In this paper, a transfer function was obtained for a PWM high speed solenoid valve controlled metal belt CVT system. The transfer function was defined as the ratio of speed ratio to PWM duty ratio and derived in time domain by linear regression analysis from the experimental results. The transfer function obtained showed different dynamic characteristics for the up and down shift. Also, LQG/LTR controller was designed for the CVT system using the transfer function. It is seen from the experimental results that LQG/LTR control showed good performance for the speed ratio tracking and disturbance rejection. The phase difference and relatively slow response are considered due to the inaccuracy os the transfer functions, which resulted from the inherent nonlinearities of the transmission characteristics of the metal belt CVT.

• 한국항공운항학회지
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• 제14권2호
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• pp.33-38
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• 2006

Heat transfer coefficients and static pressure distributions on a gas turbine vane endwall were experimentally investigated in a 5 bladed linear cascade. The Reynolds number based on an axial chord length and the cascade exit velocity was 500,000. Both heat transfer and pressure measurements on the vane endwall were made at the two different turbulence intensity levels of 6.8% and 10.8%. Detailed heat transfer coefficient distributions on the vane endwall region were measured using a hue detection based transient liquid crystals technique. Results show various regions of high and low heat transfer coefficients on the vane endwall surface due to several types of secondary flows and vortices. Heat transfer coefficient and endwall static pressure distributions showed similar trends for both turbulence intensity, however, the averaged heat transfer coefficients for higher turbulence intensity case was higher than the lower turbulence intensity case by 15%.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1092-1097
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• 2004

The heat (mass) transfer characteristics on the endwall surface of a first-stage linear turbine rotor cascade at off-design conditions has been investigated by employing the naphthalene sublimation technique. The experiments are carried out at the Reynolds number of $2.78{\times}10^{5}$ for two incidence angles of -5% and +5%. The positive incidence angle results in intensification of the pressure-side leg of a leading-edge horseshoe vortex, which delivers higher heat transfer along its trace. On the other hand, the negative incidence angle show an opposite tendency.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1479-1482
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• 2004

LMTT (Linear Motor-based Transfer Technology) is horizontal transfer system in the maritime container terminal for the port automation. The system is driven by PMLSM (Permanent Magnetic Linear Synchronous Motor) that is consists of stator modules on the rail and shuttle car. This paper investigates the effect of the drop height of container on impact reaction force of the Impact Absorber (IA) in shuttle car for LMTT. The results of this investigation are obtained from detailed finite element analysis for various parameters, such as the spring coefficient, the drop height of container.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1856-1857
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• 2006

The existing automation transfer systems such as AGV(Automated Guided Vehicle) have many problems (maintenance, accuracy, velocity, etc.) and wastes of a vast space and time. Hence we have suggested to LMTT(Linear Motor-based Transfer Technology). This paper deals with fundamental LMTT, and proposes a concept of mass reduction and propulsion control for LMTT when it is starting and reaching an object by using lift-force. By applying optimal controller and the repulsive lift forte in the LMTT, a large percent of vehicle weight is compensated and it reduces friction, then it needs less thrust force to propel the vehicle.

• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.221-230
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• 2007

This paper deals with analytical prediction for electromagnetic characteristics of a tubular linear actuator with Halbach array using transfer relations, namely, Melcher's methodology. Using transfer relations derived in terms of magnetic vector potential and a two-dimensional (2-d) cylindrical coordinate system, this paper derives analytical solutions for magnetic vector potential due to permanent magnets (PMs) and stator winding currents. On the basis of these analytical solutions, this paper also achieves analytical solutions for the magnetic fields distribution produced by PMs, stator windings current and axial thrust. The analytical results are validated extensively by finite element (FE) analyses. In particular, test results such as thrust measurements are given to confirm the analysis. Finally, this paper estimates control parameters using analytical solutions and test results such as thrust, back-emf, inductance and resistance measurements.

• 대한기계학회논문집
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• 제16권5호
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• pp.952-964
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• 1992

본 연구에서는 2차원 정사각형 밀폐공간내에 열복사를 흡수, 방사 및 비등방 산란하는 매질이 존재할 때 자연대류와 복사의 상호작용을 선형 비등방 산란을 가정 하고 복사열전달의 계산시 P-N 근사법을 이용하여 해석하였다. 수치계산을 통하여 Planck 수, 산란알베도, 광학두께, 벽방사율 및 비등방 산란이 유동 및 온도 특성 그리고 열전달에 미치는 영향을 조사하였다.