• International Journal of Control, Automation, and Systems
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• 제3권4호
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• pp.533-541
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• 2005

In this paper, a wind turbine with power splitting transmission, which is realized through a novel three-shaft planetary, is presented. The input shaft of the transmission is driven by the rotor of the wind turbine, the output shaft is connected to the grid via the main generator (asynchronous generator), and the third shaft is driven by a control motor with variable speed. The dynamic models of the sub systems of this wind turbine, e.g. the rotor aerodynamics, the drive train dynamics and the power generation unit dynamics, were given and linearized at an operating point. These sub models were integrated in a multidisciplinary dynamic model, which is suitable for control syntheses to optimize the utilization of wind energy and to reduce the excessive dynamic loads. The important dynamic behaviours were investigated and a wind turbine with a soft main shaft was recommend.

• 디지털산업정보학회논문지
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• 제16권4호
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• pp.29-42
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• 2020

SCADA (Supervisory Control and Data Acquisition) systems for remote monitoring, data acquisition and control are applied to major industrial infrastructures including power, water and railroad. Recently, there are many researches on key management scheme for secure communication due to change to the open network environment. These systems are located at far distances and are connected to the main control center through various types of communication methods. Due to the nature of these systems, they are becoming the significant targets of cyber attack. We propose an efficient key management scheme which is established on ID-based cryptosystem without an expensive computation on MTU (Master Terminal Unit), Sub-MTU, and RTU (Remote Terminal Unit). The proposed method is secure and effective in key management among multiple legitimate devices.

• 한국기계가공학회지
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• 제14권5호
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• pp.134-140
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• 2015

A control program of an engine control module (ECM) was developed, and its control performance was verified on a 750Ps marine diesel engine. The control method was designed for an engine rotational speed control system. For ECM hardware, the commercial rapid control prototype (RCP) ECM was used. The programming tool for control algorithm development was the MatLab/Simulink. The main control algorithm assembled many control models as engine cranking, run, and stall. Each model has sub-models to input/output control signals. The target engine speed was input signal from a speed control lever, and control output signal of the ECM was sent to the unit-injectors for fuel injection. The engine test was performed under various conditions of engine rotational speeds and dynamometer loads. The test results show that the control function of the ECM is suitable for electrical marine diesel engines.

• 설비공학논문집
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• 제20권4호
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• pp.245-251
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the operating characteristics and performance of a simultaneous heating and cooling heat pump in the heating-main operating mode were investigated experimentally. The system adopted a variable speed compressor with four indoor units and one outdoor unit with R-410A. In the heating-main mode, the cooling capacity was lower than the design cooling capacity due to the reduction of the flow rate in the indoor unit for the cooling, with the increase of the heating capacity. To solve these problems, the performance characteristics of the simultaneous heating and cooling heat pump in the heating-main mode were investigated by varying the flow rate to the indoor unit for the cooling and the compressor rotating speed. In addition, the adequate control methods were suggested to improve the system efficiency.

• 한국통신학회논문지
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• 제16권10호
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• pp.992-1000
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• 1991

현대는 생산성 향상을 위하여 이런 방법이 사용되는데 그중 공장 측면에서는 공장 자동화를 함으로서 생산성 향상을 기하는 방법을 사용하고 있다. 공장 자동화의 첫 단계는 각 단위 공장의 자동화이다. 우리나라 현황을 보면 소수의 발전된 공장의 경우 라인의 자동화가 구축되어 있으며 대다수의 기업은 단위 공정의 자동화 장치가 설치되고 있다. 그러나 현재 설치된 장비로서 더 이상의 생산성을 높이기 위해서는 각 단위 공정간의 협력 또는 공조체계 및 사무자동화와의 인계가 이루어져야 한다. 이에 본 논문에서 제시된 공정 감시 제어 SYSTEM은 각 공정의 자동화를 이루고 각 단위 공장의 자동화를 이루고 각 단위 공정을 MAIN COMPUTER와 연결하여 모든 공정을 MASTER SYSTEM화하여 통계처리 및 감시 기능을 하고자 하여 생산성을 향상시키고자 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.336-340
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• 1996

This paper presents the development of a collocated capacitance sensor and its application to the decentralized PID controller design for 4-axis magnetic bearing system. The main feature of the sensor is that it is made of a compact printed circuit board (PCB) so that it can be built in to the actuator coil of the magnetic bearing unit. The signal processing unit has been also developed. Then, decentralized PED controller is designed using simplified rotor system model. Finally, the experimental results on the performance of the collocated sensor based decentralized PID controller for a magnetic bearing rotor system is presented.

• 한국정보처리학회논문지
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• 제2권3호
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• pp.277-287
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• 1995

멀티미디어 통신 단말기를 이용하여 다자간 영상회의를 구현하기 위하여 단말기들 은 논리적으로 상호 연결되어 있어야 하며, 단말기 사이의 연결을 구현하는 방법에는 중앙 집중식 방식과 분산식 방식이 있다. 이중 집중식 영상회의의 구현을 위하여 다 지점 제어 장치가 필요하며, 이러한 다지점 제어장치를 설계하기 위한 방법에는 음성 및 영상처리 장치의 개발 방법에 따라 디지탈에 의한 방식과 아날로그에 의한 방식으 로 크게 나눌 수 있다. 이러한 다지점 제어장치의 의미 및 개발방법을 살펴보기 위하 여, 본 논문에서는 다지점 제어 장치에 대한 주요기능을 정리하였으며, 다지점 제어장 치의 구현을 위한 여러 방법들을 제시하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.195-198
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• 1996

The control objective of drum level of boiler in thermal power plant is to maintain drum level at constant setpoint regardless of disturbance such as main steam flow. The initial response of the drum level loop process is in a direction opposite to the final response. The drum level loop shows inverse response when the power is changed abruptly. We adopt fuzzy controller using knowledge base considering system dynamics for controlling drum level. Finally, the simulation result using the digital simulator for boiler system in Seoul Power Plant Unit 4 shows the validity of fuzzy controller.

• 한국ITS학회 논문지
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• 제5권3호
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• pp.24-28
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• 2006

본 논문에서는 메인 제어 보드에 연결되는 디바이스 모듈 보드들을 자동하는 인식하는 새로운 자동화 시스템을 설계 및 구현하였다. 본 논문의 시스템은 메인보드와 디바이스 모듈 보드로 나누어 설계하였으며, 메인보드에는 모듈보드와 연결할 수 있도록 슬롯 구조에 의해 설계되었다. 제안된 슬롯구조는 장착이 편리하고 기능의 추가 및 확장이 가능하도록 하였다. 또한 장치 보드들을 자동으로 인식함으로 통해 새로운 기존의 시스템을 업그레이드하거나 새로운 디바이스의 추가하는 등의 기능변경이 용이하도록 시스템을 설계 및 개발하였다. 본 논문에서 제안 된 시스템은 K10S1 PLC를 가지고 실험 및 검증하였다. 실험 분석 결과 제품의 기능향상에 드는 간 및 비용의 단축 효과가 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1438-1440
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• 2005

A power control and distribution unit(PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU scheme for the small LEO Satellite applications. The main constitutes of the PCDU are the battery interface module, the auxiliary supply modules, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation. and instrument power distribution modules.