• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.2 s.21
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• pp.51-60
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• 2006

The objective of this research is to develop a least cost system design method for branched storm sewer systems while satisfying all the design constraints using heuristic techniques such as genetic algorithm and harmony search. Two sewer system models have been developed in this study. The SEWERGA and SEWERHS both determine the optimal discrete pipe installation depths as decision variables. Two models also determine the optimal diameter of sewer pipes using the discrete installation depths of the pipes while satisfying the discharge and velocity requirement constraints at each pipe. Two models are applied to the example that was originally solved by Mays and Yen (1975) using their dynamic programming(DP). The optimal costs obtained from SEWERGA and SEWERHS are about 4% lower than that of the DP approach.

• Journal of Practical Engineering Education
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• v.9 no.1
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• pp.49-56
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• 2017

Recently, due to Industry 4.0, there is a great interest in smart factory for productivity improvement and customer satisfaction in manufacturing industry, and construction is also actively pursued by government support. In particular, data integration and fieldbus communication technology to build an efficient production system are essential. Fieldbus is an open control system that is not tied to a specific vendor system and has various advantages such as compatibility with other products, accuracy of data transmission, and remote diagnosis. However, there are no educational equipment for training field buses, training courses and examples for practical training, and there are many limitations in improving the practical skills needed for building smart factories in the industrial field. Therefore, this study develops PLC based fieldbus education equipment and training course based on previous research results that selected PLC and communication technology suitable for domestic industry field for practical fieldbus training and develops the training program of Ethernet IP, Profibus DP, Modbus, CC-Link, and DeviceNet. In addition, it is confirmed that the control and remote diagnosis of distributed field devices are possible by data collection and monitoring.

• Journal of the Korean institute of surface engineering
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• v.33 no.2
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• pp.107-114
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• 2000

In this study, we investigated the possibility of the application of the EzROBO system to direct shaping techniques which can make arbitrary shapes without any specific mold. We formed arbitrary shapes using raw materials of EH-260D (Epoxy＋Binder) with the conditions of $250\mu\textrm{m}$ layer thickness, 0.2MPa working pressure, 20mm/sec working velocity, and 1.8mm needle thickness. The developed Spatial Printing Technique showed enhanced working velocity and lower cost than existing 3DP process, and is expected to replace the existing process through the process optimization in the future.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1266-1268
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• 2001

ProfiBus provides real-time data communication among field devices in the EMU (Electrical Multiple Unit) and TCMS (Train Control Monitoring System). This paper presents an adapt to Train Communication Network for EMU using ProfiBus DP(Decentralized Periphery) mathod, which is the layer 2 DDLM(Direct Data Link Mapper) protocol of ProfiBus.

• Journal of the Microelectronics and Packaging Society
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• v.4 no.1
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• pp.31-38
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• 1997

대용량, 고속정보처리가 요구되는 B-ISDN용 스위칭 모듈은 90년초부터 MCM으로 제작후 사용되어 왔다. 특히 MCM은 Data 처리의 고속성 및 회로의 고집적이 요구되는 ATM, GPS 및 개인휴대 통신 분야에 광범위하게 개발 및 응용되고 있다. 따라서 본논문에 서는 고속, 고집적 ATM 교환기의 Switching Module을 제품의 Low Cost와 다충회로를 간 단하게 구현할수 있는"Diffusion patterning"(이하 DP)공정과 기보유중인 Thin Film 공정으 로 MCM을 구현하였다.CM을 구현하였다.

• Proceedings of the Korean Society for Information Management Conference
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• 1995.08a
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• pp.83-86
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• 1995

본 연구에서 구축된 멀티미디어 도서관 정보시스템은 대학도서관을 기본 모형으로 하여 설계하였다. 이 시스템은 7 개의 모듈 즉 참고문헌제공 전문가시스템, 학술지 브라우징, 멀티미디어 데이타베이스, 텍스트 데이타베이스(온라인 열람목록, OPAC), 외부데이타베이스(온라인/CD-ROM/인터넷 데이터베이스), 도서관 이용안내, 시스템이용법으로 구성된다. 시스템의 구현 환경은 IBM 컴퓨터 466DX2/Dp을 사용하고 시스템 개발도구로는 하이퍼텍스트 기능이 첨가된 멀티미디어 저작 도구인 멀티미디어 툴북을 이용하고 이용자 인터페이스는 메뉴방식을 채택하였다.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.87-92
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• 2001

This technical note is intended to introduce a state-of-the-art offshore construction vessel. This unique vessel is for multi-purpose Field Development Ship (FDS) for deepwater to ultra-deepwater. The FDS is a construction vessel with dynamic positioning (DP) system intended to develop offshore oil and gas field in water depth up to 3000 m. The design criteria and main capacities of the vessel are discussed.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.1
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• pp.8-19
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• 2003

Special purpose vessels such as drillship and ocean research vessels install the DPS(Dynamic Positioning System) to maintain the position and heading for long-time operation. This paper deals with the design parameters for the control theory and filter algorithms of DP system. for the environmental loadings wind forces, current forces and wave forces were considered. In order to estimate the low frequency motions without first-order wave motion, the Kalman filter was used and it was assumed that the first-order wave forces correspond to system noises and first-order wave motions are measurement noises. In this simulation, the length of research vessel is 65 meters and it has four thrusters to maintain the position. The ability of keeping position and heading was confirmed. For the calculation of thruster input the LQR and LOI control theory were adopted and the effects of gain were investigated.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.808-815
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• 2003

Fieldbus technology is having a massive impact on the development of faster, smarter and less expensive industrial networking systems. However, there have been a few of practically applied cases and channels for obtaining technical advices. Moreover, the users in the industry don't trust the Fieldbus technology like they didn't trust PLC control system in 1970s. Therefore, in this paper, Air flow control system is constructed by Fieldbus technologies, Profibus and Inverter that controls the motor speed. With the features of the motor control, the amount of electric power consumption by the speed control of motor is measured by the constructed control system. From this measured result, the effectiveness of the airflow control system and Feasibility to the practical industry field is demonstrated To improve the confidence of Fieldbus technology, practically embodied cases and technical methods are presented.

• Journal of Ocean Engineering and Technology
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• v.29 no.5
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• pp.380-385
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• 2015

In the development of an underwater construction robot, the reliability of the operating system is the most important issue because of its huge maintenance cost, especially in a deep sea application. In this paper, we propose a new redundant architectural design for the hydraulic control system of an underwater construction robot. The proposed architecture consists of dual independent modular redundancy management systems linked with a commercial profibus network. A cold standby redundancy management system consisting of a preprocessing switch circuit is applied to the signal network, and a hot standby redundancy management system is adapted to utilize two main controllers.