• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1484-1486
• /
• 1998

Recently, extending the local broadcasting and increasing lots of informations, the low-loss communication cable is required in proportion as frequency. The reason of transportation loss causes to using the high frequencies like hundreds of MHz or decades of GHz. For the low transportation loss, it is required the developing-technology of foaming and the high foamed insulator with the dielectric ratio of the nearest to 1. Therefore, there is the purpose of developing the insulating materials for the low dielectric ratio. Also it is important to measure the attenuation, which is one of the important parameters, as the evaluation of transportation characteristic with frequency in the communication cable. In this paper, the result showed that the dielectric ratio(1.4) of the nearest to 1 and low attenuation with high frequency were very related to the transportation and reflection characteristics such as propagation velocity(82.27%), delay time and voltage standing wave ratio(VSWR).

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1982.10a
• /
• pp.29-32
• /
• 1982

본 논문은 광섬유 케이블의 설계에 있어, 케이블 공정에 따른 광손실의 증가를 최소로하는 케이블의 구조 및 광케이블의 포설에 따른 잔류 응력의 억제 등, 장기간 동안 케이블의 전송특성을 유지하며, 광섬유의 파단 방지를 목표로 고려해야할 사항을 논하였다. 광섬유의 특성을 유지하기 위해서는 광섬유 제조시 사용되는 재질 및 적정 Dimension 설정이 필요하며 광섬유 파단 방지를 위해 CABLE내에 TENSION MEMBER를 수용하는 구조를 검토, 광섬유 CABLE 포설시 광섬유의 파단 확률을 감소시키며, 광섬유의 잔류응력을 억제하는 관점에서 케이블 구조를 설계하였다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2000.11a
• /
• pp.272-276
• /
• 2000

본 논문에서는 I/O Cable을 가지는 일반 통신시스템의 전자파 방사 Mechanism을 분석하고, Design에 있어 중요한 Parameter를 도출하였다. 중요한 Design Parameter로 도출된 I/0 Cable의 Coupling mechanism을 실험 및 상용 Software를 이용한 Simulation방법에 의해 분석하고, 이에 대한 EMC Design Rule을 제시하였다. 도출된 EMC Design Rule을 준수하여 Design을 실현하고, 그 효과를 분석하였다. EMC Design Rule에 기반을 둔 개발을 통해 제품의 Redesign및 복잡한 Debug 과정이 없이 효과적으로 전자파 양립성 규격을 만족하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.9A
• /
• pp.1422-1430
• /
• 2000

S(Synchronous)-CDMA is a new cable modem technology applicable to the upstream channel for high speed multimedia communication using CATV networks. In this paper we analyze the transmitting and receiving process of S-CDMA scheme based on Terayon patent and derive bit error probability of S-CDMA and TDMA scheme in the $\varepsilon$-mixture impulse noise model which appropriately reflects impulse noise characteristics of upstream channel by using various parameters. This analysis results are a good match with the simulation results. We also compare Eb/No gain performance of S-CDMA with TDMA in 16, 32, 64, QAM.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.10
• /
• pp.2691-2695
• /
• 2009

Nowadays Fiber optical communication systems have limitless bandwidth and can be used for transmitting various multimedia data with in real time. It is necessary to construct integrated service systems that can be used in our society whole to communicate multimedia data such as text, image, audio and video data in fiber optic communication systems. In this paper, we have designed and constructed the fiber optical link application system for multi-video/audio data transmission using only one core optical cable upgrading previous fiber optical communication systems based on WDM (Wavelength Division Multiplexer). Using the proposed fiber optical link application system enables us to managing fiber optical communication systems with only one core optical cable using WDM (Wavelength Division Multiplexer) and DEWDM/Wavelength splitter.

• Korean journal of communication and information
• /
• v.41
• /
• pp.200-231
• /
• 2008

This study content-analyzed Korean cable television programs aired from Feb. 6 to Feb. 19, 2007, focusing on the contextual variables linked to violent acts. A total of 657 PAT's (perpetrator-action-target) in the 68 programs sampled were analyzed for characters' age, sex, type, relationship, and motivation, humorization, punishment for their violent acts, and finally reality of violence. According to the results, (1) most violence occurred among male characters, who were at their ages between 20 and 39; (2) more than half of the total violent acts happened among acquaintances including family members; (3) anger, retaliation, personal or group interest, and violence for fun were ranked at the top tiers of the motivation list; (4) most violences were overlooked without punishment; (5) and about 80% of the whole violence were realistic. In terms of program types, (1) female perpetrator and victims appealed more often in drama than the other genres; (2) violence among acquaintances and simple fun as motivation were prevalent most in entertainment programs; (3) every violent act in children's programs was done by unrealistic characters. According to the analysis by program ratings, (1) while least violence appeared in '19 and older', all of the violent acts were portrayed as realistic; (2) humorization were most prevalent in the 'everyone' rating; (3) and female perpetrators and victims appealed most in the programs rated as '15 and older'. Generally, various contextualized violences displayed different distributions according to program types and ratings. The qualitative features of the current findings about cable television violence provide a fundamental data for future studies, which will explore the subsequent effects of violent media contents.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.2
• /
• pp.245-250
• /
• 2017

From the instant of installation and operation, power cables start deteriorating. Cable systems can be maintained not only by monitoring the insulation status of the insulation layer and oversheath, but also the insulation status of the terminal and junction in high-voltage power cables. When the cable system (the cable itself and cable junctions combined) deteriorates, fire accidents happen due to dielectric breakdowns. We have invented a device to monitor the deteriorating status of cables, and installed it at Korea Western Power Co. Ltd. located in Taean, Chungcheongnam-do Province. In this paper, we present the results obtained using our device, through analysing and calculating the standard deviation of leakage current from cable insulators attached to the cables. When the standard deviation of analysed leakage current falls below a critical value, a cable system is deemed to be operating safely. But when the standard deviation of analysed leakage current is larger than the critical value, the insulation status of the terminal and junction in the cable system is considered to have seriously deteriorated. The terminal and junction in the relevant system should then be replaced preemptively in order to prevent blackout accidents of cables caused by the suspension of power supply.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1465-1467
• /
• 2004

Compared with other transport means, safety and timeliness are the merits of railways. Unexpectedly when accident happens, much time and human strength are required to cope with the accident. And for swift recovery, systematic rehabilitation is needed. Recently using MTS(Moving picture Transmission System), we can perform accident rehabilitation and recording work efficiently. MTS is the device that transmits continuous picture information from accident field to control center. e are developing the appropriate system to railway situation to make use of the existing information communication technology, processing technology of video-tex, super high speed transmission technology through fiber-optic, copper cable and network description of information Technology, etc. If these communication-based can technologies are applied to railway system, railway managers can control the accident by inspecting the picture of accident field and can contribute to the safe train operation and the improvement of railway management. In this paper, we investigate the connecting methods when optical fiber is used for moving picture data transmission of train accidents, and its problems. And, we validate MTS's performance through about 28km section of field test.

• Journal of the Korean Society of Safety
• /
• v.13 no.3
• /
• pp.96-101
• /
• 1998

In order to study the change in mechanical properties and anti-flammablilty of ethylene-ethylacrylate copolymer(EEA) very low density polyethylene(VLDPE) compound that could be used as communication cable sheath using $Mg(OH)_2$ as a non-toxic flame retardant, 100, 125, and 150phr $Mg(OH)_2$ were added to 100 parts of EEA-VLDPE compound, 100 EEA : 0 VLDPE, 50 EEA : 50 VLDPE, and 0 EEA : 100 VLDPE, respectively. $Mg(OH)_2$ was a good non-toxic flame retardant for communication cable sheath and anti-flammability increased with the amount of $Mg(OH)_2$ in compound. The mechanical properties-MI, Ts, and Eb-decreased with increasing in the mixing ratio of EEA but oxygen index(OI) increased with increasing in the amount of EEA. The best composition of $Mg(OH)_2$ in this study was 150phr to 50 EEA : 50 VLDPE compound for the anti-flammability.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1410-1411
• /
• 2007

This paper analyses current densities induced inside a worker using AC arc welder. Applying the boundary element method, we calculate current densities induced in organs inside a worker in case he was located at 1[cm], 3[cm], 5[cm], 10[cm], 15[cm], 20[cm] far from a power cable of AC arc welder. As results of study, we find a maximum current density induces at a heart surface and may be higher than 10[$mA/m^2$] of ICNIRP guideline if he works within 15[cm] from a power cable.