• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1547-1549
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• 1994

In recent years, fiberoptic technology is becoming indispensable in establishing communication networks due to its low loss, high capacity and non-inductive properties. In the power industry as well, the technology is being required to cable and facility monitering, and control system. But, duct in the manhole and space in the culvert are required to fiberoptic cable that is separated from power cable. Therefore, some cable makers and R&D has been studying the composite fiber/power cables. This report introduces the outline of ABF system, construction and properties of optical composite power cable that used ABF technology.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.409-411
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• 2003

As power demand increases gradually, the call for underground transmission system increases. But it is very difficult and high in cost to construct new ducts and/or tunnels for power cables in metropolitan areas. HTS (High Temperature Superconducting) cable has the several useful characteristics such as increased power density. Therefore HTS cable can allow more power to be moved in existing ducts, which means very large economical and environmental benefits. In this paper, we carried out investigation for Application of 22kV class HTS cable in Korean utility networks. The results show that the HTS cable is applicable to replace IPB in pumping-up power plant, withdrawal line in distributed generation, withdrawal line in complex power plant, and conventional under ground cable. Finally, as the cost of HTS wire and refrigeration drops, the technical and economical potential of HTS cable is evaluated positively.

• Progress in Superconductivity and Cryogenics
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• v.5 no.2
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• pp.20-29
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• 2003

As power systems grow more complex and power demands increase, the need of underground transmission system is increasing gradually. But it is very difficult and high in cost to construct new ducts and/or tunnels for power cables in metropolitan areas. HTS (High Temperature Superconducting) cable can carry very high current densities with strongly reduced conductor loss and allow high power transmission at reduced voltage. Therefore HTS cable can transfer more power to be moved in existing ducts, which means very large economical and environmental benefits. A development project for a 22kV class HTS cable is ongoing at a research centers, and the cable manufacturer in Korea. In this paper, we carried out investigation for application of 22kV class HTS cable in Korean utility networks. The results show that the HTS cable is applicable to replace IPB in pumping-up power plant, withdrawal line in distributed generation, withdrawal line in complex power plant, and conventional under ground cable. Finally, as the cost of HTS wire and refrigeration drops, the technical and economical potential of HTS cable is evaluated positively.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.286-291
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• 2013

Home CATV networks comprise coaxial cables and signal splitters which have less than ideal characteristics. Home network testing facilities use long lengths of coaxial cables, often undesirably coiling and bending the cable, stressing joints on connectors. Cable connectors, cable placement, bending and flexing can cause leakage of signals and can result in undesired signal paths in a system causing deteriorated performance. The purpose of this paper is to bring to light the issues of signal leakage and radiation from shielded media such as RG-59 and RG-6 coaxial cables, furthermore signal splitters have less than ideal characteristics.

• Structural Engineering and Mechanics
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• v.54 no.2
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• pp.337-362
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• 2015

This paper presents a feasibility study on structural damage alarming and localization of long-span cable-supported bridges using multi-novelty indices formulated by monitoring-derived modal parameters. The proposed method which requires neither structural model nor damage model is applicable to structures of arbitrary complexity. With the intention to enhance the tolerance to measurement noise/uncertainty and the sensitivity to structural damage, an improved novelty index is formulated in terms of auto-associative neural networks (ANNs) where the output vector is designated to differ from the input vector while the training of the ANNs needs only the measured modal properties of the intact structure under in-service conditions. After validating the enhanced capability of the improved novelty index for structural damage alarming over the commonly configured novelty index, the performance of the improved novelty index for damage occurrence detection of large-scale bridges is examined through numerical simulation studies of the suspension Tsing Ma Bridge (TMB) and the cable-stayed Ting Kau Bridge (TKB) incurred with different types of structural damage. Then the improved novelty index is extended to formulate multi-novelty indices in terms of the measured modal frequencies and incomplete modeshape components for damage region identification. The capability of the formulated multi-novelty indices for damage region identification is also examined through numerical simulations of the TMB and TKB.

• Structural Engineering and Mechanics
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• v.6 no.5
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• pp.517-527
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• 1998

This paper describes an exact method of analysis for natural vibration of diagonal networks by considering an equivalent cyclic periodic structure and adopting the double U-transformation technique. Both a lumped mass system and a distributed mass system are considered to investigate the diagonal networks. The exact solution for the frequency equations and the natural modes of the networks can be derived. As numerical examples, square diagonal cable networks with different meshes are worked out.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.456-463
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• 2000

Bidirectional cable TV networks using HFC(Hybrid Fiber Coaxial) networks need MAC (Medium access control) protocols to have efficient access in upstream channels. In this paper, we have studied and evaluated several contention resolution algorithms and mapping of higher layer traffic described in IEEE 802.14 and MCNS (Multimedial Cable Network System) MAC protocols with respect to IP, ABR and CBR traffic types. IEEE 802.14 MAC protocol demonstrates better performance for transmitting ATM cells while the MCNS MAC protocols for the IP traffic.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.269-276
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• 2004

There exist several types of distributed subscriber networks using Asymmetric Digital Subscriber Line(ADSL), Very high -bit rate Digital subscriber Line(VDSL), and Data Oner Cable Service Interface Specifications(DOCSIS). The efficient and concentrated network management of those several distributed subscribers networks and resources requires the general management information model of network, which has abstract and conceptual managed objects of the heterogeneous networks and its equipment to manage the integrated subscriber network. This paper presents the general Internet subscribers network modeling framework using RM-ODP to manage that network in the form of integrated hierarchy. This paper adopts the object-oriented development methodology with UML and designs and implements the HFC network of DOCSIS as an example of the subscriber network.

• 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.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.3
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• pp.17-25
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• 2004

Internet Service Subscribers Network has a new role of providing various multimedia services to the home. However, there exist several types of distributed subscriber networks using Asymmetric Digital Subscriber Line (ADSL), Very high-bit rate Digital Subscriber Line (VDSL), and Data Over Cable Service Interface Specifications (DOCSIS). The efficient and concentrated network management of those several distributed subscribers networks with resources requires the general network information model, which has and conceptional managed objects independent of type of network and its equipment to manage the integrated subscriber network. This paper presents the general Internet subscribers network model of the managed object to manage that network in the form of integrated hierarchy. This paper adopts the object-oriented development methodology with UML and designs and implements the integrated subscribers NMS of cable data network and VDSL network as examples of the subscriber networks.