• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.127-134
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• 2001

Wire ropes are widely used in cable car, suspension bridge and elevator, etc. and composed of single or multi-layer strands. It is difficult to find out the characteristics of a strand or wire rope because of complicated geometry and contact condition. In this study, the axial stiffness is evaluated using finite element method and reliable finite element analysis model is presented, taking into consideration the convergence on the length. The axial stiffness predictive equation of a strand is developed using analysis of variance, which can be applicable for characterizing the relationship between load and displacement when the strand configuration is determined.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1997.10a
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• pp.239-242
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• 1997

Subscriber network investment cost is a main cost element among those constituting the access charges in telephone networks. The purpose of this paper to estimate the investment cost of installing a subscriber network in a typical metropolitan area and to develop a cost modeling framework. To this aim, a metropolitan area in Seoul was investigated. The main cost elements were identified and their relationships with the cable technology, geographical characteristics, and the number of subscribers were analyzed. The findings could be used to design an enhanced cost proxy models for estimating the access charges in a multi-operator environment.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.369_370
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• 2009

This paper describes the fault location method for HVDC submarine cables. Most conventional fault location methods can be applied in off-line. However, in this paper, on-line fault location algorithm is proposed using multi-scale correlating of wavelet coefficient and travelling wave. The propagation velocity is measured by field test on Jeju-Heanam submarine cable section. Finally, the fault location algorithm is tested by same system modeling using EMTP/ATP.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.573-581
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• 2004

A self-contained wall climbing robot, called MRWALLSPECT (Multi-functional Robot for WALL inSPECTion) II, is developed. It is designed for scanning external surfaces of gas or oil tanks with small curvature in order to find defects. The robot contains all the components for navigation in itself without any external tether cable. Although it takes the basic structure of the sliding body mechanism, the robot has its original characteristic features in the kinematic design with closed link mechanism, which is enabled by adopting a simple and robust gait pattern mimicking a biological system. By employing the proposed link mechanism, the number of actuators is reduced and high force-to-weight ratio is achieved. This paper describes its mechanism design and the overall features including hardware and software components. Also, the preliminary results of experiments are given for evaluating its performances.

• The Journal of Korea Robotics Society
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• v.9 no.4
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• pp.264-271
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• 2014

In this study, we have developed the humanoid joint modules which provide a variety of service while living with people in the future home life. The most important requirement is ensuring the safety for humans of the robot system for collaboration with people and providing physical service in dynamic changing environment. Therefore we should construct the mechanism and control system that each joint of the robot should response sensitively and rapidly to fulfill that. In this study, we have analyzed the characteristic of the joint which based on the target constituting the humanoid motion, developed the optimal actuator system which can be controlled based on each joint characteristic, and developed the control system which can control an multi-joint system at a high speed. In particular, in the design of the joint, we have defined back-drivability at the safety perspective and developed an actuator unit to maximize. Therefore we establish a foundation element technology for future commercialization of intelligent service robots.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.11-15
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• 2013

We in order to use WLAN communication device planned wireless USB dongle internal antenna of 2.4 GHz/5.8 GHz band. So it uses square patch dual-wideband and quality is satisfactory and it designed print folded monopole antenna of the shape which is simple. The thickness of the antenna was fed by a $50{\Omega}$ coaxial cable feeding 1mm dielectric constant 4.4 FR4 substrate was used. The overall size of the antenna is $20mm{\times}50mm$. So the internal antenna is suitable. Measurement results of the fabricated antenna, the return loss of more than 10 dB in the two bands could be obtained. Radiation pattern has a maximum gain of 3.75 dBi value.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.105-109
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• 2002

The short-term AC breakdown strength of laminated polypropylene insulating Paper (PPLP) has been studied for cold dielectric of high temperature superconductivity power cables. The design and operating conditions of the electrode system for studying of short-term breakdown strength of one-layer and multi-layer PPLP samples are discussed in liquid nitrogen(LN2) state. The influence of various operating factors (geometry and dimension of electrodes, speed of tested voltage, thickness of test sample) on the value of short-term AC breakdown strength at cryogenic temperature has been established.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.1
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• pp.89-104
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• 2008

The aim of this study is to analyze the distribution structure of exclusive digital muti-media broadcasting's contents. This study takes into distribution wether exclusive contents create an additional window being serviced to other media. And it investigates how the contents work in window through analysis of programming table and interview with programming editors of each DMB service company. The window effect is a same notion to the one source multi use. In the film industry, window means a movie distribution that a film can be on one after the other starting the cinema, DVD, local cable channel, and terrestrial television. The key point of this paper is how to new media, DMB, creates its additional window and changes the existing window structure.

• Electronics and Telecommunications Trends
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• v.8 no.4
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• pp.143-156
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• 1993

ISDN 을 구축하기 위한 망구조로 ISDN 의 다양한 서비스 수용 관점에서 Single Star 형 망구조가 가장 잠재력이 우수한 구조로 평가되고 있으며 Single Star 형 구조로 구축될 때 High Count Optical Fiber Cable 과 광커넥터 (단심, 다심) 가 요구된다. 그중 광커넥터는 광 가입자 망의 구축을 위해 필수적인 부품으로서 기술 추세는 다심화, 복합 기능화, 소형화, 저가격화, 고성능화, 고신뢰성화의 방향으로 진행되고 있다. 본 고에서는 향후 국내에서 적용 가능한 광케이블용 다심 광커넥터 개발을 위하여 외국에서 개발되어 있는 제품의 정렬원리, 정렬 구조 및 제조기술을 분석하였으며 또한 국내의 수요를 분석하였다. 수요 분석은 과거의 생산 실적 자료가 없는 이유로 정량적 분석법보다는 전화 가입자 수요 자료와 가입자 선로의 광케이블 계획, 그리고 광 CATV 가입자 예측 자료를 이용한 정성적인 방법을 적용하였다.

• The Journal of Information Systems
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• v.14 no.3
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• pp.59-62
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• 2005

The recent broadcasting environment has shifted to embrace multimedia and multi-channel features through terrestrial, satellite and cable media. This has multiplied the number of broadcasting programs. With the information on a myriad of programs provided to TV viewers, information overload occurs, and thus, the TV viewing environment is shifting to one where viewers cannot select programs passively. Thus, a growing need is emerging to ensure a personalized electronic program guide (EPG) to help individuals select TV programs according to their taste. This paper presents a personalized EPG that enables a purpose-oriented broadcasting service to provide personalized broadcasting programs in tune with the user's requirements and preferences.