• 대한전기학회논문지:전력기술부문A
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• 제52권9호
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• pp.487-492
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• 2003

This paper analyzes an eigenvalue distribution and enhancement of the small signal stabiligy when an Unified Power Flow Controller (UPFC) modeling is connected into the multi-machine power system. Recently a lot of attention has been paid to the subject of dynamic stability. It deals with analysis of eigenvalue sensitivities with respect to parameters of UPFC Controller and damping of interarea and local electromechanical oscillation modes using UPFC Controller. It provides an insight and understanding in the basic characteristics of damping effects of UPFC Controller and shows a very stable frequency response via UPFC in test model. The series branch of the UPFC is designed to damp the power oscillation during transients, while the shunt branch aims at maintaining the bus voltage and angle. Comprehensive time-domain simulation studies using PSS/E show that the proposed robost UPFC controller can enhance the small signal stability efficiently in spite of the variations of power system operating conditions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.825-830
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• 2005

Traffic control is the center of the railway traffic control system. The main objective of railway traffic control system is to minimize delays, providing the customers with on-time train operating service according to the given train schedule. Particularly, within the station control area, the departure & arrival of train. the decision on the train priority and the shunting of train are decided by the authority of the local traffic controller. Therefore, it is necessary to have a lot of information and communications between each departments. And for such decision making of the local traffic controller, not only the communication between each stations are needed, but also the communication between other stations are needed too. In this paper, we have analyzed the main work of the local traffic controller in large scale stations and have designed the station traffic control system needed to be built within the station considering the local traffic. And we have proposed not only the communication with other system within station, but also the communication methods for communications with the neighboring stations.

• 전기전자학회논문지
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• 제22권2호
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• pp.518-521
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• 2018

차량 내부의 다양한 전자장치를 연결하는 차량 내 통신(IVN: in-vehicle network)은 실시간성, 저잡음성, 고신뢰성, 고유연성 등이 필요하며 CAN(controller area network), CAN-FD(CAN flexible data rate), FlexRay, LIN(local interconnect network), SENT(single edge nibble transmission), PSI5(peripheral sensor interface 5) 등 다양한 기술이 있다. 본 논문에서는 이들 기술의 동작 원리에 대해 살펴보고 각 기술의 적용 대상과 장단점에 대해 설명한다.

• 전자공학회논문지B
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• 제33B권6호
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• pp.208-216
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• 1996

This paper presents a decentralized control scheme for interconnected systems with unmodeled nonlinearities and interactions using a neural coordinator. The interactions due to the interconnection and the unmodeled nonlinearity associated with each subsystem are represented by the deviations from linearized states of decomposed subsystems. the decentralized controller is composed of local controllers and a neural coordinator. The local controller for each subsystem is derived from linearized local system parameters y linear optimal control theory. the neural cooridnator generates a corrective control signal to cancel the effect of deviation sthrough the backpropagation learning with the rrors obtained form the difference of the local system outputs and reference model outputs. the reference model consists of the part of local system without deviations. The effectiveness of the proposed control scheme is demonstrated by simulation studies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.452-455
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• 1997

It is well known that Variable Structure Controller(VSC) is robust to parameters variation and disturbance but its performance depends on the design parameters such as switching gain and slope of sliding surface. This paper proposes a more robust VSC that is composed of local VSC's. Each local VSC considers the local system dynamics which has narrow parameter variation and disturbance. We optimize the local VSC's by use of Evolution Strategy, and then we use Artificial Neural Network to generalize the local VSC's and construct the overall VSC in order to cover the whole range of parameter variation and disturbance. Simulation on BLDC motor current control has verified the proposed VSC is superior to the conventional VSC.

• 대한전자공학회논문지
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• 제26권10호
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• pp.1498-1506
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• 1989

A new stabilization scheme is proposed in which the local state feedback is utilized in each decentralized controller for large-scale interconnected systems. In the proposed scheme, the controller is designed in two steps. First, the feedback gain of each decentralized controller is temporarily chosen so that the eigenvalues of each isolated subsystem are placed at the desired locations in the complex plane. Secondly, the feedback gain of each controller is compensated so that the time derivative of the Lyapunov function candidate for the overall closed-loop system should be negative. A sufficient condition which assures the global system to stable is given.

• 한국통신학회논문지
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• 제9권4호
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• pp.153-156
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• 1984

Nopersistent CSMA제어절차에 의하여 지역망 콘트롤러를 제작하였으며 버퍼 레지스터를 사용하여 마이크로 컴퓨터와 인터페이스 시켰다. 네트워크는 로우드의 변화에 대한 버스의 이용률을 최적화시키기 위하여 패킷 재송신 시간을 $2^n$의 함수로 조정하였다. 메시지는 패킷으로 만들어져 128바이트씩 버스에 전송되며 물리층에서 최대 데이터 전송 속도는 19,200bps를 얻었다.

• 전기전자학회논문지
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• 제20권3호
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• pp.333-336
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• 2016

차량 내 전자장치에서 효과적인 서브 버스로서 표준화된 저속 직렬 통신 프로토콜인 LIN(local interconnect network)이 개발되었다. 본 논문에서는 LIN 버전 2.2A를 기반으로 LIN 제어기를 Verilog HDL을 이용하여 구현하였다. 구현된 LIN 제어기는 FPGA에서 동작을 확인하였으며 IP 형태로 제공되어 SoC 시스템에 통합이 가능하다. 0.18um 공정에서 합성하였을 때의 게이트 수는 약 2,300 게이트이다.

• 한국ITS학회 논문지
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• 제8권2호
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• pp.45-52
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• 2009

본 논문에서는 기존의 전구방식 신호등과 비교하여 LED신호등의 교통신호기 간 신호 안전성 측면의 연계 호환성을 실험 검토하고 보완 방안을 설계하여 제안하였다. 실험 분석 결과 신호의 안전성을 향상하기 위하여, 교통신호기의 출력 누설전류에 따른 LED신호등의 OFF 상태 누설전압의 과다로 인한 문제와, 누전상황 대응에 대한 문제에 대하여 보완이 필요한 것으로 나타났다. 보완을 위한 교통신호기 규격의 개선 방안은 220V 전원을 기준으로 출력 누설전류 허용 값을 기존의 8mA사양에서 3mA로 변경하고, 출력전압 평가의 기준을 기존의 25-45V에서 65-75V로 변경하는 것이며, LED신호등 규격의 개선 방안은 기존과 동일하게 95V이하에서 OFF상태를 유지하도록 함에 더하여 OFF상태에서 10Kohm이내의 임피던스를 유지하도록 하는 내용을 추가하는 것이다.

• 대한전기학회논문지
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• 제43권4호
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• pp.543-552
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• 1994

This paper presents a decentralized quadratic regulation architecture with feedforward neural networks for the control problem of complex systems. In this method, the decentralized technique was used to treat several simple subsystems instead of a full complex system in order to reduce training time of neural networks, and the neural networks' nonlinear mapping ability is exploited to handle the nonlinear interaction variables between subsystems. The decentralized regulating architecture is composed of local neuro-controllers, local neuro-identifiers and an overall interaction neuro-identifier. With the interaction neuro-identifier that catches interaction characteristics, a local neuro-identifier is trained to simulate a subsystem dynamics. A local neuro-controller is trained to learn how to control the subsystem by using generalized Backprogation Through Time(BTT) algorithm. The proposed neural network based decentralized regulating scheme is applied in the power System Stabilization(PSS) control problem for an imterconnected power system, and compared with that by a conventional centralized LQ regulator for the power system.