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New State Feedback Control for Series Resonant Converter (직렬공진형 컨버터의 새로운 상태궤환 제어)

  • 조일권;김만고;이대식;윤명중
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.8
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    • pp.828-835
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    • 1990
  • A new state feedback control scheme is proposed to improve the stability and dynamic performances of the series resonant converter (SRC). The proposed scheme can be easily implemented without speed limitation. Design parameter of the proposed control is the ratio of the state feedback gains. A closed loop dynamic modeling for the SRC with the proposed control law is derived. Parametric curves which can be used to select the design parameter in the control system are presented. The experimental results show that the excellent dynamic performance of the converter can be obtained by properly selecting the design parameter. The results are further compared with both the theoretical analysis and the frequency control.

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Remote Control of a Mobile Robot using Embedded web server (Embedded web server를 이용한 이동로봇의 원격제어)

  • Park, Jeong-Hoon;Kim, Jin-Geun;Kang, Moon-Sung
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2693-2695
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    • 2005
  • In this paper, we developed a more efficient system for the remote control and monitoring of a wheeled mobile robot using internet without spatial limitation. The hardware configuration of the remote control system for a wheeled mobile robot includes a client PC executed on the remote site, a embedded web-server and a mobile robot with many measuring equipments. The communication between a client PC and a embedded web-server is implemented through internet. And the Bluetooth module is used for connecting a embedded web-server and a mobile robot. A GUI program has been developed by using JavaScript in order to easily control a mobile robot on a client PC.

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A Design Method for Keum jeong Elementary School (금정초등학교 계획을 위한 방법론 탐색)

  • Choi, Doo-Won
    • Journal of the Korean Institute of Educational Facilities
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    • v.4 no.3
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    • pp.57-62
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    • 1997
  • This research is intended to establish the design method for Keum Jeong Elementary School. Establishing the design method is based on the participatory method of Davidson Elementary School designed by Sanoff. Due to the limitation of space and time given to the task which is to design the open school for Keum Jeong Elementary School, the design method is proposed not as the direct participatory method but as the indirect one. The indirect participatory design for Keum Jeong Elementary School is performed by various fields' specialists consisted of practical architect, architectural theorist, and the one who is professionally interested in pedagogy, etc.

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A Study on Evaluation Index for Remodeling of Elementary School (초등학교(初等學校) 리모델링을 위한 건축계획적(建築計劃的) 평가지표(平價指標)의 연구(硏究))

  • Oh, Byeong-Uk;Lee, Jae-Hoon
    • Journal of the Korean Institute of Educational Facilities
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    • v.11 no.4
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    • pp.5-14
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    • 2004
  • The elementary schools constructed before 1990's are old fashioned and have limitation in corresponding to 7th education curriculum and social demands. So remodelling of existing elementary schools is increasingly popular to satisfy the new need, but it is true that the decision of remodelling has been made by the authority of the administrative and the most of remodelling results have shown the simple increasing of spaces. So this research is trying to suggest an evaluation index model for judging whether school buildings should be remodelled or not, and what parts should be remodelled in the aspects of architectural planning by extracting 4 space planning elements; function, requirement, activity, arrangement and grading rates on these elements.

A Study on the Implementation of Inheritance Anomaly in Concurrent Programming (병행 프로그래밍에서 상속 이상의 구현에 관한 연구)

  • Cho, Myung-Hyun;Lee, Myung-Un
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.54 no.1
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    • pp.53-57
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    • 2005
  • When concurrency is integrated to programming language, problem more than inheritance remains yet. Because more than inheritance happens by collision or cross fire between synchronization and inheritance of same time object, when synchronization code is not detached properly from method code about same time object, it makes expanded of code to make derivation class change synchronization code of super class and method code. In this paper, minimize right of inheritance method, When subclass is introduced to new synchronization limitation condition, wish to solve problem more than inheritance of three types that happen in same time programming embodying C++ class that do so that can avoid alteration of method reed.

Dynamic Selection of Neural Network Modules based on Cellular Automata for Complex Behaviors (복잡한 행동을 위한 셀룰라 오토마타 기반 신경망 모듈의 동적선택)

  • Kim, Kyung-Joong;Cho, Sung-Bae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.4
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    • pp.160-166
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    • 2002
  • Since conventional mobile robot control with one module has limitation to solve complex problems, there have been a variety of works on combining multiple modules for solving them. Recently, many researchers attempt to develop mobile robot controllers using artificial life techniques. In this paper, we develop a mobile robot controller using cellular automata based neural networks, where complex tasks are divided to simple sub-tasks and optimal neural structure of each sub-task is explored by genetic algorithm. Neural network modules are combined dynamically using the action selection mechanism, where basic behavior modules compete each other by inhibition and cooperation. Khepera mobile robot simulator is used to verify the proposed model. Experimental results show that complex behaviors emerge from the combination of low-level behavior modules.

A Simple and Robust Digital Current Control for a PM Synchronous Motor under the Parameter Variations

  • Kim, Kyeong-Hwa;Baik, In-Cheol;Young, Myung-Joong
    • Journal of Electrical Engineering and information Science
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    • v.3 no.2
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    • pp.174-183
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    • 1998
  • A simple and robust digital current control technique for a permanent magnet (PM) synchronous motor under the parameter variations is presented. Among the various current control schemes for an inverter-fed PM synchronous motor drive, the predictive control is known to give a superior performance. This scheme, however, requires the full knowledge of machine parameters and operating conditions, and cannot give a satisfactory response under the parameter mismatch. To overcome such a limitation, the disturbances caused by the parameter variations will be estimated by using a disturbance observer theory and used for the computation of the reference voltages by a feedforward control. Thus, the steady-state control performance can be significantly improved with a relatively simple control algorithm, while retaining the good characteristics of the predictive control. The proposed control scheme is implemented on a PM synchronous motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative simulations and experiments.

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A New Approach to Torque Control of Variable Reluctance Motors (Variable Reluctance 모터의 토크 제어를 위한 새로운 방식)

  • 김창환;허헌;하인중;고명삼;김동일
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.6
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    • pp.971-981
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    • 1994
  • In this paper, we consider feedback-linearizing control of VR (Variable Reluctance) motors which have been increasingly used in high performance direct-drive applications. We characterize all torque controllers that can make the generated torque of a VR motor linear to torque command but without torque ripple. The torque controlles maximize the range of torque commands which are admissible under the physical limitation in stator currents. The whole class of all such torque controllers is parameterized in the explicit form which contains a function to be chosen freely. This free function can be used to achieve other control objectives as well as linear dynamic characteristics. As the examples for optimal choices of the free function, we actually determine two optimal free functions, one for minimal rate of change in current commands and the other for minimal power loss due to stator resistance. To illuminate further the practical use of torque controllers proposed in this paper, we present some experimental results for the case of a commercially available VR motor.

Forecasting technics for variable frequency control of PWM inverter using one-chip $\mu$-com (One-chip $\mu$-com을 이용한 PWM 인버터의 가변 주파수 제어 추정 기법)

  • Park, Jung-Gyun;Kim, Hyun;Choi, Hyun-Young;Yeo, Duk-Gu;Oh, Se-Ho;Kim, Yang-Mo
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1055-1057
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    • 2001
  • The switching circuit of PWM inverter is very complicated. By using one-chip $\mu$-com the complication of switching circuit is possible to be diminished. But because in one-chip $\mu$-com the limitation of processed memory size exists, the switching handling method has to be simple. In this paper, to effectively utilize the switching handling, we presented the estimation method of PWM pulses which is different form the conventional PWM switching method by the comparison.

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A new Dynamic Multilayer Perceptron Structure (새로운 동적 멀티레이어 퍼셉트론 구조)

  • Kim, Dong-Won;Oh, Sung-Kwun
    • Proceedings of the KIEE Conference
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    • 2000.11d
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    • pp.806-808
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    • 2000
  • We propose a new Dynamic Multilayer Perceptorn(DMP) architecture for optimal model identification of complex and nonlinear system in this paper. The proposed DMP scheme is presented as the generic and advanced type based on the GMDH(Group Method of Data Handling) method for the limitation of GMDH under only two system input variables. It is worth stressing that the number of the layers and the nodes in each layer of the DMP are not predetermined, unlike in the case of the popular multilayer perceptron structure, but these are generated in a dynamic manner. The experimental part of the study comes with representative nonlinear static system. Comparative analysis is included and shows that a new DMP can produce the model with higher accuracy than previous other works.

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