• 산업경영시스템학회지
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• 제35권3호
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• pp.163-172
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• 2012

Regarding project management, many organizations have developed and distributed general project management knowledge systems, and application fields use the knowledge systems to apply the process suitable for characteristics of a project. This study suggests project management process models to apply to system integration projects. This system integration project management process model is composed of six top processes of initiation, preparation for contract, planning, implementation management, coordination and control, and termination and transfer. The five processes are re-divided into 25 bottom processes. These processes are expressed as input, control, output, and mechanism by using the IDEF0 model. For this model development, it has chosen the items which constituted a process through a questionnaire of experts.

• 대한산업공학회지
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• 제13권2호
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• pp.17-34
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• 1987

Modern telecommunication switching systems are SPC (Stored Program Control) machines handling voice, data and other kinds of traffic, in an environment which tends to be fully digital switching and transmission. The throughput of such systems is determined by the real time capacity of its centralized or distributed control processors and by the traffic capacity of the switching network. Designers must verify the traffic and call processing capacity of the switching system and check its performance under traffic load before it is put into service. Verification of traffic and call processing capacity of switching systems is one of the problems treated by teletraffic studies; teletraffic studies are based on stochastic process, queueing theory, simulations and other quantitative methods of decision making. This paper reviews the general methodologies to evaluate the throughput and performance of the digital switching system. TDX-10, which is a fully digital switching system under development in ETRI, is employed to give illustrative examples of the methodologies discussed in this paper.

• 전기전자학회논문지
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• 제2권2호
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• pp.270-277
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• 1998

네트워크 발전으로 인하여 제어시스템은 집중화에서 분산화 된 아키텍춰를 지향하고 있다. 그러나 이러한 제어시스템은 범용 운용 시스템을 기반으로 설계되어 공정처리에서 요구되는 실시간 성을 보장하기는 미흡한 점이 많아 플랜트의 제어설비로서 실시간 운영체제를 탑재한 제어시스템이 점차로 증가하고 있다. 본 논문에서는 분산제어 시스템의 기능을 위해 운영체제는 실시간 성을 보장하는 조건을 만족하도록 실시간 처리 능력, 실시간 응답의 신뢰성 및 멀티 프로세스의 기능구현에 중점을 두었으며, 이 운영체제의 바탕 위에 주요 공정처리의 기능인 루프, 로직의 가능한 처리 수를 분석하고, 이의 타당성을 검토하였다. 그리고 온라인 시 처리중인 데이터에 영향을 미치지 않는 시스템을 설계하고, 절체에 소비되는 시간을 측정 하였다.

• Smart Structures and Systems
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• 제5권3호
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• pp.241-260
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• 2009

Shape control of flexible structures using piezoelectric materials has attracted much attention due to its wide applications in controllable systems such as space and aeronautical engineering. The major work in the field is to find a best control voltage or an optimal placement of the piezoelectric actuators in order to actuate the structure shape as close as possible to the desired one. The current research focus on the investigation of static shape control of intelligent shells using spatially distributed piezoelectric curve beam actuators. The finite element formulation of the piezoelectric model is briefly described. The piezoelectric curve beam element is then integrated into a collocated host shell element by using nodal displacement constraint equations. The linear least square method (LLSM) is employed to get the optimum voltage distributions in the control system so that the desired structure shape can be well matched. Furthermore, to find the optimal placement of the piezoelectric curve beam actuators, a genetic algorithm (GA) is introduced in the computation model as well as the consideration of the different objective functions. Numerical results are given to demonstrate the validity of the theoretical model and numerical algorithm developed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.883-886
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• 1999

Recently, with the development of computer technology, field instrument and control system using in industrial fields have changed from mechanical, electrical systems to digital electronic systems. Distributed control system(DCS), control functions are dispersed for grading up reliability and informations are combined fur effective management has been developed and sold. As this system has been enlarged and complicated, it is difficult to testing the system and very important to verifing functions systematically. In this report, function test procedure which is performed spontaneously by domestic or foreign DCS manufacturer was searched and analyzed. As its results, the test procedure of DCS functions were proposed. The proposed procedure was applied to DCS being used for a thermal power plant. The function test for DCS requires continuous and dynamic input/output signals, therefore we proposed the method to compose virtual plant which simulate the DCS functions with. And we suggested the test procedure of each DCS function.

• 한국산학기술학회논문지
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• 제8권2호
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• pp.232-239
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• 2007

전력산업의 구조개편과 더불어 분산전원의 배전계통연계운용 및 전력품질이 전력회사의 배전사업자, 구역전기사업자, 전기공급 신뢰도와 밀접한 관계에 있는 산업용 수용가들에게 많은 관심을 불러일으키고 있다. 최근, 이러한 주변정세는 차세대의 배전계통이 다수의 차세대 전력공급네트워크(Micro-grid)들로 구성될 것이라고 하는 예상을 전문가들로부터 제기되기에 이르렀다. 그러나, 제안된 Micro-grid는 몇몇의 분산전원과 전력품질을 보상하는 기기, 그리고 통신제어설비와 부하들로 구성된다는 기본적인 내용에 지나지 않는다. 따라서, 본 논문에서는 수용가에 고신뢰 고품질의 전력공급을 가능하게 하는 차세대 전력공급네트워크인 Micro-grid의 Topology와 그 운전제어앨고리즘을 제안한다.

• 대한전기학회논문지:전력기술부문A
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• 제53권3호
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• pp.152-160
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• 2004

A novel UPQC(Unified Power Quality Conditioner), which consists of series inverter, shunt inverter, distributed generation system, is proposed. The proposing system can compensate reactive power, harmonics, voltage sag and swell, voltage interruption etc. through the change of paralleling operation mode and islanding operation mode. The control strategy for the proposing system was derived using the instantaneous power method. The performance of proposing system was analyzed by means of the PSCAD/EMTDC simulation and the experimental work with the hardware prototype. The proposing system has the ultimate capability of improving power quality at the point of installation on power distribution systems or Industrial power systems and can be utilized for the custom power device in th future distribution system.

• 한국산학기술학회논문지
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• 제10권1호
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• pp.81-90
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• 2009

전력산업의 구조개편과 더불어 분산전원의 배전계통연계운용 및 전력품질이 전력회사의 배전사업자, 구역전기사업자, 전기공급 신뢰도와 밀접한 관계에 있는 산업용 수용가들에게 많은 관심을 불러일으키고 있다. 이러한 주변정세는 차세대의 배전계통이 다수의 Micro-grid들로 구성될 것이라고 하는 예상을 전문가들로부터 제기되기에 이르렀다. 그러나, 제안된 Micro-grid는 몇몇의 분산전원과 전력품질을 보상하는 기기, 그리고 통신제어설비와 부하들로 구성된다는 기본적인 내용에 지나지 않는다 따라서, 본 논문에서는 수용가에 고신뢰 고품질의 전력공급을 가능하게 하는 차세대 전력공급네트워크인 Micro-grid의 적정전압유지를 위한 자율분산협조 운용제어 알고리즘을 제안한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1205-1210
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• 2004

The 4-20mA analog signal used in the various industrial fields to interface sensor in distributed process control has been replaced with relatively simple digital networks, called "fieldbus, and recently by Ethernet. Significant advances in Internet and computer technology have made it possible to develop an Internet based control, monitoring, and operation scheduling system for heating, ventilation and air-conditioning (HVAC) systems. The seamless integration of data networks with control networks allows access to any control point from anywhere. Field compatible field devices become so-called "smart" devices, capable of executing simple control, diagnostic and maintenance functions and providing bidirectional serial communication to higher level controller. The most important HVAC of BAS has received nationwide attention because of higher portion of more than 40% in building sector energy use and limited resources. This paper presents the Internet-based monitoring and control architecture and development of LonWorks control modules for AHU (air handling units) of HVAC in viewpoint of configuring BAS network. This article addresses issues in architecture section, electronics, embedded processors and software, and internet technologies.

• 대한산업공학회지
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• 제40권1호
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• pp.34-42
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• 2014

SCADA and DCS that have performed automatic control and monitoring activities increase the productivity of enterprise in industries. In such systems, although their performance had been improved, there are still many deficiencies in predictive maintenance which can foresee the risk of any kinds of accidents. Because the data acquisition systems of main facilities are being distributed throughout the whole plant and therefore, integration of data obtained from the systems is very difficult. Accordingly, techniques that acquire meaningful information from the gathered data through realtime analysis still need to be improved. This paper introduces a developed facility monitoring system which can predict equipment failure and diagnose facility status through big data analysis to improve equipment efficiency and prevent safety accidents.