• Journal of Sensor Science and Technology
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• v.32 no.3
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• pp.199-206
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• 2023

This study presents a novel monitoring technique for underwater high-voltage direct current (HVDC) cables based on the Distributed Acoustic Sensor (DAS). The proposed technique utilizes vibration and acoustic signals generated on HVDC cables to monitor their condition and detect events such as earthquakes, shipments, tidal currents, and construction activities. To implement the monitoring system, a DAS based on phase-sensitive optical time-domain reflectometry (Φ-OTDR) system was designed, fabricated, and validated for performance. For the HVDC cable monitoring experiments, a testbed was constructed on land, mimicking the cable burial method and protective equipment used underwater. Defined various scenarios that could cause cable damage and conducted experiments accordingly. The developed DAS system achieved a maximum measurement distance of 50 km, a distance measurement interval of 2 m, and a measurement repetition rate of 1 kHz. Extensive experiments conducted on HVDC cables and protective facilities demonstrated the practical potential of the DAS system for monitoring underwater and underground areas.

• Journal of KIISE:Software and Applications
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• v.32 no.10
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• pp.963-973
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• 2005

Increasing attention is being recently devoted to various problems inherent in the topological design of networks systems. The topological structure of these networks can be based on service centers, terminals (users), and connection cable. Lately, these network systems are well designed with tiber optic cable, because the requirements from users become increased. But considering the high cost of the fiber optic cable, it is more desirable that the network architecture is composed of a spanning tree. In this paper, we present a GA (Genetic Algorithm) for solving bicriteria network topology design problems of wide-band communication networks connected with fiber optic cable, considering the connection cost, average message delay, and the network reliability We also employ the $Pr\ddot{u}fer$ number (PN) and cluster string in order to represent chromosomes. Finally, we get some experiments in order to certify that the proposed GA is the more effective and efficient method in terms of the computation time as well as the Pareto optimality.

• Explosives and Blasting
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• v.13 no.4
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• pp.28-38
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• 1995

This paper was addressed by fall seminar of society of explosives engineers of Korea. In Japan, total length of cable was 600km and tokyo was 260km and it will extend cable tunnel 5~10km every year in Tokyo. NTT service project has been working as a optic fiber net works and in 2010, it will be done. FIF. FTTH so call fiber to the home for the purpose of multiplicity. For the above project. First, it should be developing auto Non-excavation tech, 2nd developing soil recycling system.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.184-185
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• 2007

90년대 후반 부터의 초고압 XLPE 케이블 시스템의 연구개발 및 납품 성과에 힘입어 국내 업계 최초로 2006년 미국시에 345kV 광복합 XLPE 케이블 시스템을 수주하였다. 본 논문은 미국 뉴욕주 최대 전력시스템 운용 회사인 KeySpan사가 발주하여 LS전선이 Turn-Key 방식으로 수주, 뉴욕주 롱아일랜드에 성공적으로 준공하여 운전 중인 345kV XLPE 광복합 케이블 시스템 project에 대하여 기술하고 있다.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.79-84
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• 1990

Analog systems could not fully deal with instrumentation and control facilities in power plants since these facilities have become more and more complex on account of various needs for large power generation capacity highly cost effective operation to conserve energy and operation management to prevent pollution. Digitalizations of control device and augmentations of control informations increased the necessity of fiber optic data networks which have excellent noise immunity and high quality wide-band with information transfer capability. The goal of this study is to offer a fiber optic data-way system which has high reliabilities, high data transmission rates and small cable ducts with large transmission capacities for the instrumentation and control of power plants.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.535-536
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• 2018

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.683-687
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• 1988

Digitalization of processor and increase of control information need the fiber optic data network which has excellent noise immunity and high-quality, widebaudwidth information transfer capability. It is aimed to offer a fiber optic dataway system for measuring and control the power plant, that has high reliability, high data transmission rate and small cable duct with large transmission capacity.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.3
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• pp.110-114
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• 2011

The recent development of 4G mobile communication system has led to the rapid technology shift from conventional repeater systems using coaxial cable links towards new fiber optic repeater systems using fiber-optic links between the base station and the outdoor fiber optic repeater. The technical changes have brought up the increasing needs of robust optic links that can be used in harsh environments. Based on the most demanding requirements, a new outdoor optical connector employing 2-channel fiber optics, uplink and downlink, has been developed for the applications where the rugged environmental protection is essential. This paper describes the development of the new connector along with the design criteria and performance results. In summarizing, the prototype optical connectors have undergone extensive laboratory and field test, and they have shown exceptional optical and mechanical characteristics under extreme environmental conditions. The connectors have also exhibited capabilities of providing fast and easy installation while maintaining high performance fiber optic connections.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1837-1839
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• 1998

This paper proposes the strain-insensitive temperature sensing in quasi-distributed sensor system using different thermal expension coefficient materials. This system has the high sensitivity and hasn't the necessity of reference signal. We can monitor the condition of the power cable with this system.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.559-566
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• 2016

Cables for Towed Array Sonar System(TASS) were developed. In order to verify the performance of cables, environmental and operational conditions as well as functional requirements were investigated during design stage. Double armored high and low voltage integrated cable for towed body and two kinds of cables, armored and light weight power and optic hybrid cables for towed array sensor system were developed by modeling and simulation. Customized manufacturing process and test method, such as foam extrusion and dynamic fatigue test were applied to this development. In conclusion, underwater towed hybrid cable with high tensile strength and compact structure were developed.