• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.268-272
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• 1989

To avoid the use of position sensor or flux sensor in a field oriented induction machine drive system, the terminal quantities are often used to estimate the rotor flux. Since the estimation involves the leakage inductance of the machine, the performance of such systems is sensitive to the variations of leakage. Since estimation of the stator flux is independent of the leakage, the steady state performance of the stator flux oriented system is insensitive to the leakage inductance. In this paper, the torque response of stator flux oriented system is compared to that of rotor flux oriented system by digital simulation. And induction motor sensor less speed control by stator flux oriented method is developed. The performance of the speed estimation is showed by digital simulation.

• Asia pacific journal of information systems
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• 제10권4호
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• pp.37-56
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• 2000

This study proposes the concept and measurement of object-oriented systems modelling activity based on the previous research in the area of systems engineering, object-oriented modelling, and information systems. The modelling activity is related to information systems development success for exploring the correlation of each other. The object-oriented modeling activity is found to be related to user satisfaction with developed information systems, But the modeling activity does not have relation to the other successes, such as cost, development schedule, and maintenance. This study contributes to systems development modeling research, systems success, and object-oriented systems modelling research. Practically, the results support the usefulness of object-oriented modelling effort in the field in terms of user satisfaction.

• Asian-Australasian Journal of Animal Sciences
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• 제13권2호
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• pp.167-175
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• 2000

This paper describes the magnetic orientation of bull sperm separated into the head and the flagellum treated by DTT or heparin in a 5,400G static field. Semen samples collected from four bulls (Japanese Black) were mixed to the same sperm density. One percentage triton X-100 was used to extract the plasma membrane. The intact and demembranated sperm suspensions were treated with 20, 200, 2,000 mM DTT, 100, 1,000 or 10,000 units heparin solutions at $4^{\circ}C$ for 6 days. The decondensation of the sperm nuclei treated by DTT or heparin was examined by measuring the head area at 1, 3 and 6 days. After measuring the area, each sample was exposed to a 5,400G static magnetic field generated by Nd-Fe-B permanent magnets for 24 hours at room temperature. Results showed that the sperms were separated into the head and the flagellum through the DTT treatment. Almost of the separated heads showed that their long axis oriented perpendicularly to the magnetic lines of force, and most of the long axis perpendicularly oriented heads showed that their flat plane oriented perpendicularly in a 5,400G magnetic field. Also, the demembranation of the head tended to increase those perpendicular orientations, while those perpendicular orientations of the head declined with the decondensation of the sperm nuclei. These findings suggest that strong magnetic anisotropy for the perpendicular orientation of the long axis and the flat plane of the head occurs in the sperm nuclei in a 5,400G magnetic field. The separated flagellum showed lower parallel orientation, and the separated and demembranated flagellum showed parallel orientation to the magnetic lines of force in this magnetic field. These findings suggest that weak magnetic anisotropy of the parallel orientation of the flagellum occurs in the inside components in a 5,400G field.

• 한국측량학회지
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• 제27권2호
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• pp.187-194
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• 2009

지상용 3차원 레이저 스캐너를 설계하고 개발하는데 있어서 위치 측정 결과의 정확성을 향상하기 위한 서보 모터의 선정과 서보 모터 FOC(Field Oriented Control) 제어 방식의 적용에 대한 연구이다. 개발 중인 지상용 3차원 레이저 스캐너는 360$^\circ$방위각과 270$^\circ$고도각의 스캔 범위를 가지고 있다. 이의 구현은 서보 모터인 방위각 모터와 고도각 모터의 정밀한 서보 모터 제어를 통해 실현된다. 연구 결과 FOC(Field Oriented Control)제어를 통해서 모터의 일정한 토크를 유지하면서 모터의 동작 위치 정확도를 향상할 수 있음을 확인하였다. 이러한 모터 제어는 지상용 3차원 레이저 스캐너뿐만 아니라 로보틱 토털스테이션에도 적용이 가능 할 것으로 사료된다.

• 사물인터넷융복합논문지
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• 제8권4호
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• pp.77-83
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• 2022

4차 산업혁명 시대에 맞는 다양한 대학의 기업현장 적용 교육 모델이 제시가 되고 있다. 특히 새로운 교수법과 함께 많은 기업의 맞춤형 교육을 위한 다양한 교육 모델이 연구되면서 활용성을 높여가고 있다. 기업 현장에서 필요로 하는 역량을 위한 프로젝트 중심의 교수법에 대한 연구가 최근에 가장 많이 발전되어 지고 있는 분야이다. 본 연구에서는 이러한 기업의 요구사항에 맞는 프로젝트 중심의 교수법에 대한 부분을 적용한 사례 중심의 교육과정 모델을 제안하고자 한다. 특히 블록체인과 웹 개발자를 위한 기업 맞춤형 교육 모델을 통하여 산업체 중심의 교육과정 모델을 설계하고 운영과정에 대한 사례를 중심으로 제안한다. 본 사례를 통한 모델은 산업체와 함께 심층 인터뷰 등을 통하여 현장에 맞는 교육과정 모델로 설계하여 운영이 되도록 구성하였다.

• Agricultural and Biosystems Engineering
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• 제4권2호
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• pp.50-57
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• 2003

This study was conducted to develop software which provides automatic site-specific field data acquisition, data processing, data mapping and management for precision agriculture. The developed software supports acquisition and processing of both digital and analog data streams. The architecture was object-oriented and each component in the architecture was developed as a separate class. In precision agriculture research, the laborious task of manual ground-truth data collection will be avoided using the developed software. In addition, gathering high-density data eliminates the need for interpolation of values for un-sampled areas. This software shows good potential for expansion and compatibility for variable-rate-application (VRA). The FIM (Field Information Management) computer program provides the user with an easy-to-follow process for field information management for precision agriculture.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권10호
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• pp.508-512
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• 2001

This paper investigates the problem of the speed estimation of conventional speed sensorless stator flux-oriented induction machine drive in the field weakening region and proposes a new speed estimation scheme to estimate speed exactly in transients in the field weakening region. The error included in the estimated rotor speed is removed by not a low pass filter but Kalman filter so that exact speed estimation in transients is achieved.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권7호
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• pp.494-499
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• 2000

In a conventional stator flux-oriented(SFO) induction machine drive system, the field weakening method is to vary flux reference in proportion to the inverse of the rotor speed. This paper investigates that maximum torque capability cannot be obtained in the conventional system and proposes a new selection method of flux reference to obtain maximum torque capability over the field weakening region by considering voltage, torque, and current limits.

• 한국의류학회지
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• 제23권2호
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• pp.296-306
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• 1999

This study reflects the aim of analyzing the fashion design connection with ecology. Ecology has been linked to human life through its changing relations with environment. In order to recover eco-system ecology-nature oriented methodology and technology oriented approach will suffice. On the modern design field Green design Recycling and Green marketing resulted in increasing rates of environment-friendly production and an effort to deliver environment-friendly corporate image. Based on above research ecological image on fashion design during the year 1990 to 1995 represents the following conclusion. In the fashion design field natural image primitive image nature -harmonious image material-recyling image culture-recycling image are proposed. In the technology field clean image and high-tech image are proposed. In the marketing field happy image harmonious image serious image and realistic image are proposed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1117-1119
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• 2000

An easier implementation method of the field oriented control of induction machine using Matlab/Simulink dSpace board is proposed in this paper. Space Vector PWM and Indirect Fied Oriented Control Algorithm is designed for the help of Simulink. And this system is simultaneously simulated and experimented in Matlab/Simulink environment with dSpace borad (DS1102). It is possible that Matlab and dSpace board compiler can make $'^*.c'$ and $'^*.obj'$ file of models designed in Matlab/Simulink environment automatically. Experimental results are given.