• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.27-32
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• 2008

In the signals-shadowed areas, In order to providing the suitable signals reception level repeaters are used for relay the signals. Repeater receives the weak signals and amplifies it up to required power level, The amplified signals get radiated by the various methods. Both antenna distribution and LCX(Leakage Coaxial Cable) are typical methods in the repeater and BTS signals radiation. Their applications are depended on the environment condition and frequency band. Generally the antenna distribution are used for the mobile telecommunication networks which use the higher frequency band than 500MHz. On the other side, LCX distribution is suitable to the frequency band under 500MHz. The network plan of repeater in FM, T-DMB, Fire Radio and Internal subway communication network are the typical LCX application fields. Cell planning with repeaters are based on the free space loss, LCX connection loss and actual field data. The actual field data can be the most important factor to design the network planning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.359-364
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• 2016

As cable TV networks have a media feature that is a broadband wire network, they can provide not only TV broadcasting services but also communication services. Accordingly, the cable TV network is mentioned as the optimal network for convergence of broadcasting and communication services. Recently, Available frequencies of the cable TV network have become insufficient as enhancement of video quality, increment of VoD service, and growth of high-speed internet service. This paper presents a new implementation method of switched digital video (SDV) technology that is introduced for obtaining additional frequency band. In the SDV system, only TV channels requested from viewer are sent and non-requested channels are dropped. The presented SDV uses a sharing method of TV broadcasting and communication service in a same frequency band. This method shows increase of spectrum efficient from switching of TV service channels without building a complex system.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.133-140
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• 2008

The cable TV network has delivered downward broadcasting signals from distribution centers to subscribers. Since the traditional coaxial cable has been upgraded by the Hybrid Fiber Coaxial(HFC) cable, the upward channels has expanded broadband services such as Internet. This upward channel is vulnerable to ingress noises. When the noises from the children nodes accumulated in an amplifier exceeds a certain level, that node has to be cut off to prevent the noise propagation. The node selection problem(NSP) is defined to select nodes so that the noise in each node does not exceed the given threshold value and the sum of Profits of selected nodes can be maximized. The NSP has shown to be NP-hard. In this paper, we have proposed heuristics to find the near-optimal solution for NSP. The experimental results show that interval partitioning is better than greedy approach. Our heuristics can be used by the HFC network management system to provide privileged services to the premium subscribers on HFC networks.

• Journal of Internet Computing and Services
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• v.5 no.3
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• pp.87-98
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• 2004

There are several types of distributed subscribers network 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 and resources require the general information model of network, which has abstract 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 modeling framework using RM-ODP (Reference Model Open Distributed Processing) to manage that network In the form of integrated hierarchy, This paper adopts the object-oriented development methodology with UML (Unified Modeling Language) and designs and implements the HFC network of DOCSIS as an example of the subscriber network.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.57-58
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• 2008

Recently, several kinds of superconductivity applications are implemented and evaluated in the utility power networks. The protection system for HTS(High Temperature Superconducting) power devices safe operation has not been established yet. For the protection of the HTS apparatus, a better understanding of the quench properties against fault current and appropriate protection devices are required. In this study, an algorithm of protection system is developed with respect to HTS power cable. The protection system of HTS power cable was analyzed in the simulated power system. Results obtained from simulation will provide much more decisive data in order to design a certain superconducting power device, and can give a good information for the installation in power system.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.1
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• pp.35-42
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• 1997

Subsea cable systems have a large information transmission capacity and play an important role in domestic and global information networks. However since the cables are under harsh marine environment, they are exposed to various hazards with high potential risks of damage resulting in serious economic loss. In this research a computer simulation program based on the finite difference algorithm was developed. The program is able to simulate two dimensional dynamic behaviour of a submarine cable during its laying. In order to verify the numerical results, they are compared to analytical results, showing a good agreement between the two results.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.743-746
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• 2011

An implementation for surface EMG network analysis and vertical control system of robotic arm is presented in this paper. The transmembranes are simulated by equivalent circuit and cable equation for propagation to be converted to circuit networks. The implementation is realized to be derived from the detecting EMG signal from 3 electrodes, and EMG transmembrane signals of human arm muscles are detected by several surface electrodes, high performance amplifier and filtering, converting analog to digital data and driving a servomotor for spontaneous robotic arm. The system is experimented by monitoring multiple steps vertical control angles corresponding to biceps muscle movement. The experimental results are that the vertical moving control level is measured to around 2 degrees and mean error ranges are lower 5%.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.04b
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• pp.421-428
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• 2000

The preliminary stage of structural design is very crucial step whose results have great effects on the structural performance, construction, economy, and aesthetics through the following design stages. However, it is extremely difficult to computerize the information and knowledge used in the preliminary design stage because it lacks of formality of representation of designers' experience and intuition. To address such issue the concept of an artificial neural network has been adopted to develop preliminary design system for cable-stayed bridges in this paper. The artificial neural network has been proved that it has the ability of learning design experience and providing a good design alternative.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.195-197
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• 2003

In this paper, Neural Networks is studied for estimation of XLPE cable specimen according to degradation. And these data making use of a computer-aided discharge analyser, a combination of statistical and discharge parameter was calculated to discrimination processing stage of degradation. NN has not bad recognition rate result of discrimination for degradation stage because discharge characteristics are very similar to between degradation stage. So, there is some improvement for applied NN.

• Journal of the Korean Operations Research and Management Science Society
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• v.5 no.1
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• pp.39-51
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• 1980

This paper deals with the problem of determining the capacity expansion timing and sizes of conduits and feeder cables for a given cable network configuration of a single exchange ares, which minimizes the present worth of total costs. The planning horizon is infinite and the demand of line pairs at each cabinet is assumed to be determininstically growing. As a solution method, the heuristic branch-and-bound algorithm of Freidenfelds and Mclaughlin is elaborated by adding details and some minor modifications, which generates a good near-optimal solution with far less computation than would otherwise be possible. We also develop a computer program, which is shown to be effective and efficient through the test run of an illustrative example.