• Title/Summary/Keyword: B-operator

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A study of an Active Stick Controlling System with Friction Observer (Active Stick 제어기 개발에 관한 연구)

  • Kim, Myung-Yul;Nam, Yoon-su
    • Journal of Industrial Technology
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    • v.24 no.B
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    • pp.207-214
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    • 2004
  • An active stick which supplies force feedback to the operator is developed in this study. A mathematical model of the active stick is derived, and compared with the experimental result. It turns out that the frictional torque due to the mechanical contacts of several parts of the stick is one of the major barriers to achieve high precision operation of the stick. The frictional effect of the stick is cancelled out by using a friction observer. The efficacy of the friction observer is verified through the numerical simulation. Because of the observer dynamics, there are some limitations in exact recovering the static friction and Stribeck effect. However, the friction observer follows the real friction on the average. It's anticipated that the application of the friction observer to the closed loop control of the active stick improves the performance of the displacement versus force characteristics, which will be proved experimentally in the further study.

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Study of The Cushion Characteristics in accordance with Shapes of Cushion Ring of Hydraulic Cylinder (유압실린더의 쿠션링 형상에 따른 쿠션 특성 연구)

  • Lee, Y.B.;Ko, J.M.;Park, J.H.
    • Transactions of The Korea Fluid Power Systems Society
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    • v.5 no.2
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    • pp.14-19
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    • 2008
  • Hydraulic excavator consists of booms, arms, bucket, and cylinder. The cylinder make these structures moved and the cushion parts of cylinder in operation absorb the great impact which is stemmed from high velocity and pressure at cushion parts of cylinders. The cushion technology of cylinders has a great effect on the operator's comfortable as well as protecting equipment from damage by suppressing the inertia of the hydraulic excavator. In this study, three hydraulic cylinders have different shapes of a cushion ring, respectively. we studied optimal cushion pattern by analyzing the change of cushion pressure and time, according to supply pressure and velocity variations.

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Development of Optimal Power Flow for the Ancillary Service of Reactive Power Generation under Restructuring Environment (전력산업 구조개편 환경 하에서 무효전력 보조서비스 운용을 위한 최적조류계산법 개발)

  • Song, T.Y.;Jeong, M.H.;Lee, B.;NamGoong, J.Y.;Moon, Y.H.
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.58-61
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    • 2001
  • Under restructuring, not only real power pricing but also reactive power pricing is important for the system operation Especially, making a reasonable reactive power pricing is becoming more important than any other time. In this paper, the authors set a proper power factor and price the portion of the reactive power generation that exceeds the power factor. To apply this method to an optimization problem, we developed optimal power flow based on interior point method. By using this IPM for the power system, the System operator can use this strategy for reactive power generation pricing and also the Generators can got the motivation to generate reactive power.

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A Study on the Analysis of Conductor Temperature Distribution of Underground Power Cables Buried in Ducts (관로부설 지중 전력 케이블 도체 온도 해석에 관한 연구)

  • Jeong, Seong-Hwan;Kim, D.K.;Choi, S.B.;Lee, D.I.;Kang, J.W.;Kim, H.S.;Park, J.H.
    • Proceedings of the KIEE Conference
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    • 2001.05a
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    • pp.270-272
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    • 2001
  • This paper proposes an algorithm of analyzing the conductor temperature distribution of underground power cables buried ill ducts. This algorithm used an equation of the permissible current-carrying capability of power cables. The algorithm will be given to an operator an ability to operate the underground power system in comfort.

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A Study on Visual Representation of SSR Phenomena using 3-D Graphical Animation (3차원 그래픽 에니메이션을 이용한 SSR현상의 시각적 제시에 관한 연구)

  • Park, I.K.;Lee, J.;Yoon, Y.B.;Kim, T.K.;Song, H.S.;Shin, J.H.
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.89-91
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    • 2000
  • This paper presents a new method for representing SSR(Subsynchronous Resonanace) Phenomena using 3-D computer graphics animation. A virtual power system simulation environment was made for simulation and visualization of SSR phenomena. It is anticipated that the proposed method would be helpful for the operator training as well as power system education.

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Self-Organizing Fuzzy Control of a Flexible Joint Manipulator (유연 관절 매니퓰레이터의 자기 구성 퍼지 제어)

  • Park, J.H.;Lee, S.B.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.8
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    • pp.92-98
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    • 1995
  • The position control of flexible joint manipulator is investigated by applying the self-organizing fuzzy logic controller (SOC) proposed by Procyk and Mamdani. The SOC is a heuristic rule-based controller and a further extension of an ordinary fuzzy controller, which has a hierachy structrue which consists of an algorithm being identical to a fuzzy controller at the lower ollp and a learning algorithm accomodating the performance evalution and rule modification function at the upper ollp. This form of control can be used in those complex systems which have been too difficult to control or which in the past have had to rely on the experience of a human operator. Even though the significant dynamic coupling of the motors and links on the flexible joint manipulator, the performance of command-following is good by applying the proposed SOC.

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Noise Reduction in Tractor Cabin (트랙터 운전실의 소음 저감에 관한 연구)

  • Kim, Wonjin;Eun, Myoungwoo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.4
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    • pp.380-384
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    • 2014
  • This study focused on identifying the major noise source in a tractor cabin using experimental methods. The noise levels in a tractor cabin for different engine revolution speeds were analyzed to identify the noise source. The results showed that the power steering unit (PSU) was the major noise source in a tractor cabin. The PSU was moved to the outside from the inside of the cabin in order to reduce the noise in the tractor cabin. As a result, the noise levels on the left and right sides of the operator in the tractor cabin were reduced by 6.8 and 3.9 dB, respectively. Finally, the window method was introduced to evaluate the contribution of the transmission noise. The orders of significance in the tractor noise were the front, bottom, and left area, successively.

Automatic Categorization of Clusters in Unsupervised Classificatin

  • Jeon, Dong-Keun
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.1E
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    • pp.29-33
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    • 1996
  • A categorization for cluster is necessary when an unsupervised classfication is used for remote sensing image classification. It is desirable that this method is performed automatically, because manual categorization is a highly time consuming process. In this paper, several automatic determination methods were proposed and evaluated. They are four methods. a) maximum number method : which assigns the tharget cluster to the category which occupies the largest area of that cluster b) maximum percentage method : which assigns the target cluster to the category which shows the maximum percentage within the category in that cluster. c) minmun distance method : which assigns the target cluster to the category having minmum distance with that cluster d) element ratio matching method : which assigns local regions to the category having the most similar element ratio of that region From the results of the experiments, it was certified that the result of minimum distance method was almost the same as the result made by a human operator.

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Face Tracking Using Skin-Color and Robust Hausdorff Distance in Video Sequences

  • Park, Jungho;Park, Changwoo;Park, Minyong
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.540-543
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    • 1999
  • We propose a face tracking algorithm using skin-color based segmentation and a robust Hausdorff distance. First, we present L*a*b* color model and face segmentation algorithm. A face is segmented from the first frame of input video sequences using skin-color map. Then, we obtain an initial face model with Laplacian operator. For tracking, a robust Hausdorff distance is computed and the best possible displacement t. is selected. Finally, the previous face model is updated using the displacement t. It is robust to some noises and outliers. We provide an example to illustrate the proposed tracking algorithm in video sequences obtained from CCD camera.

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A Study on the Development of International Multimodal Transport System in Korea in Terms of Systems Approach (국제복합일관수송체제에 관한 고찰)

  • 신동춘
    • Journal of Korean Society of Transportation
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    • v.5 no.1
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    • pp.85-99
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    • 1987
  • The transport a administration in Korea is meeting demands of developing international multimodal transport system. In the past, as Korea transport policy has been emphasizing on the passenger traffic, the physical distribution sector is far behind international trend. Regarding the urging necessities of reducting costs in transport in order to upgrade the competitive edge of industries, Korea has to develop the most efficient transport system so called international multimodal transport system. The existing transport system is inefficient because each transport mode is separate, so this system is aiming at reducing cost and time and developing freight transport. The scope and scheme of this thesis should be as following. Chapter 2. Systems Approach of International multimodal transport 1. general systems theory 2. definition of International multimodal transport system 3. MTO (multimodal transport operator) Chapter 3. Current Situation and Problems of this System. 1. international law and practice 2.current situation A. Europe B. U.S. C. Japan D. Korea Chapter 4. Policy Goal for Improving this System Chapter 5. conclusion.

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