• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.5
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• pp.306-316
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• 2003

본 논문에서는 소프트웨어 PLC를 구현하는 방안을 제시하였다. 하드웨어는 표준적인 산업용 PC와 입출력 보드들로 구성된다. 운영체제로는 수십 마이크로초의 정밀한 단위로 태스크들의 스케줄링이 가능한 실시간 리눅스를 사용하였다. 소프트웨어 PLC를 위해 개발한 실시간 태스크들은 실시간 리눅스의 커널 모드에서 실행되며, 사용 목적에 따라 작성된 PLC 프로그램을 해석하고 실행하는 작업을 일정한 주기로 반복한다. 또한 PLC 프로그램을 편리하게 작성할 수 있도록 자체 프로그램 문법을 제안하고 이를 위한 컴파일러도 구현하였다. 이렇게 구현된 PLC는 가격 대비 성능이 우수하며 소규모의 응용분야들에 유용하게 활용할 수 있다.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2601-2604
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• 2003

원전 안전계통에 적용될 PLC는 엄격한 내진, 전자파, 내환경 시험기준을 만족해야 하며, 원전 안전등급에 부합되는 안전성 및 신뢰성을 만족해야 한다. 전 세계에서 안전계통에 적용될 PLC는 Siemens 의 Teleperm XS, Invensys 의 Triconex, WestingHouse 의 AC-160 이 있으며, 국내에서는 원전 안전계통 개발시 전적으로 이들 PLC 수입에 의존하고 있다. 현재 한국원자력연구소와 국내 PLC 제조회사간에 공동과제를 통해 안전등급 PLC 개발을 수행하고 있으며, 본 논문에서는 개발될 PLC 의 설계기준과 개발된 하드웨어 및 소프트웨어 사양 등 개발현황에 대해 기술한다.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.2
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• pp.207-215
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• 2004

The PLC programming by IEC1131-3 is hard to handle to ordinary users as well as professionals. Also it has not a generality, so that it couldn't be debugging some logic errors easily. In order to be adapted for such environment, In this paper, I have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user is converted to the C code which can be used in a commercial editor such as Visual C++. The detection of logical errors in C code is more effective than PLC programming itself. ISPLC provides the GUI-based interface in web environment and an easy programming platform to such beginners as well as professionals. The study of code conversion of LD to IL as well as IL to C is firstly tried in the world as well as KOREA. To show the effectiveness of the developed system, I applied it to a practical case, a real time traffic control system. ISPLC is minimized the error debugging and programming time owing to be supported by windows application programs.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.161-163
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• 2015

본 논문은 교통 혼잡도가 높은 월계 2교 4거리 교차로에 센서를 이용하기 위한 교차로 PLC 프로그램을 개발하는 것을 목적으로 한다. 이를 위해 교차로에서 발생하는 차량사고와 혼잡을 방지하지 위한 소프트웨어 요구사항 명세서(SRS)를 정의하고, 이를 바탕으로 소프트웨어 설계서를 작성한다. 또한 XP-Builder 시뮬레이터를 사용하여 센서기반 교차로 신호등 PLC 프로그램을 구현한다.

• KSBB Journal
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• v.20 no.3
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• pp.149-163
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• 2005

Recently preparative liquid chromatography (PLC) has been used more frequently to separate drugs and natural substances. This modern separation methodologies require reliable tools that perform on a high level in terms of efficiency and reproducibility. However, large-scale PLC easily tends to reduce the yield and purity of the product. To promote the separation efficiency of PLC, we need to properly understand the controlling effects of the process, which may enable to predict the process and to improve the design and operation of PLC. Progress in computer technology allows the use of sophisticated models, provided their parameters can be measured. Some hardwares as well as softwares for PLC were already commercially available. In this work, the separation characteristic of PLC will be reviewed and compared on both the software and the hardware.

• Journal of KIISE:Software and Applications
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• v.32 no.2
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• pp.108-118
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• 2005

The software of the nuclear power plant digital control system is a safety-critical system where many techniques must be applied to it in order to preserve safety in the whole system. Formal specifications especially allow the system to be clearly and completely specified in the early requirements specification phase, therefore making it a trusted method for increasing safety. In this paper, we discuss a systematic method, which generates PLC-based FBD programs from the requirements specification using NuSCR, a formal requirements specification method. This FBD programs takes an important position in design specification. The proposed method can reduce the possible errors occur in the manual design specification, and the software development cost and time. To investigate the usefulness of our proposed method, we introduce the fixed set-point rising trip example, a trip logic of BP in DPPS RPS, which is presently being developed at KNICS.

• Journal of the Korea Computer Industry Society
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• v.2 no.4
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• pp.425-434
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• 2001

In this paper, a series of processes to configure a feedback control system by using a PID controller in a programmable logic controller (PLC). The PLC (SIMATIC S7-400) with a PID module (FM455C) is connected by online to an IBM PC with the Windows environment, which serves as a PLC programmer. PID controllers including P/PD/PI controllers have been designed in order to show design procedures, and finally, a PID controller for the plant of cart system. Performances of the control system have been investigated by the MATLAB simulation, the simulation in the PLC programmer. Physical performances have been recorded and examined for the real cart system.

• Journal of KIISE:Software and Applications
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• v.37 no.1
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• pp.54-59
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• 2010

Special-purpose microcontrollers PLCs have been widely used in the area of industrial automation. For the research of analysis and verification for PLC programs, first of all we have to specify formal sematics of PLC programming languages. This paper defines formally the operational semantics of LD language. After we transform the graphical language LD into its textual representation Symbolic LD, we give semantics of Symbolic LD since LD language is a graphical language. This paper defines the natural sematics of Symbolic LD and formalizes it in Coq proof assistant.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.4
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• pp.297-303
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• 2005

In this paper, I developed an intelligent multi agents based softPLC(IMPLC). In IMPLC, the standard IEC 1131-3 PLC languages(LD, SFC, FBD, ST) programmed by a user are converted to IL, which is one of intermediate codes, in order to make them interactions. And then the IL is converted to the standard C code regarding some extension and transplanting, which can be used in a commercial editor such as visual C++. In IMPLC, the logical errors and syntax errors occurred by users are detected, so that the optimal PC control based softPLC can be possible. IMPLC provide easy programming platform to such beginner as well as professionals. The study of code conversion is firstly tried in the world as well as KOREA. I applied IMPLC to 3 steps conveyer belt system. The simulation results say that the debugging steps by IMPLC using multi agents are decreased than the conventional softPLC's.

• Journal of KIISE:Software and Applications
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• v.32 no.12
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• pp.1271-1282
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• 2005

Recently, PC-based control is incredibly developed in the industrial control field, but it is difficult for PLC programming in PC. Therefore, I need to develop the softeware PLC, which support the international PLC programming standard(IECl131-3) and can be applied to diverse control system by using C language. In this paper, I have developed the ISPLC(Intelligent Agent System based Software Programmable Logic Controller). In ISPLC system, LD programmed by a user which is used over $90\%$ among the 5 PLC languages, is converted to IL, which is one of intermediate codes, and IL is converted to the standard C rode which can be used in a commercial editor such as Visual C++. In ISPLC, the detection of logical error in high level programming(C) is more eaier than PLC programming itself The study of code conversion of LD->IL->C is firstly tried in the world as well as KOREA. I developed an execution engine with a good practical application. To show the effectiveness of the developed system, 1 applied it to a practical case, a real time traffic control(RT-TC) system. ISPLC is minimized the error debugging and programming time owing to be supported by windows application program.