• 한국정보통신설비학회:학술대회논문집
• /
• 2004.08a
• /
• pp.215-218
• /
• 2004

통신서비스를 제공하는 전송매체인 동케이블(copper cable)은 외륵 전자기적 영향으로부터 작업자 및 시설보호를 위해 $300{\sim}500m$ 마다 접지를 하고 있다. 접지는 일반 보안용 접지와 차폐용 접지로 구분할 수 있는데 보안용 접지는 100옴 이하의 접지저항을 요구하지만 차폐용 접지는 10옴 이하의 낮은 접지저항을 필요로 한다. 차폐용 접지는 대표적으로 전력선 또는 전철시설로부터 발생하는 통신선에서의 유도전압(Induced voltage)을 경감시키기 위해 사용되는 것으로 차폐케이블, 유도중화코일, 차폐선 등의 선로시설에 필요하다. 본 논문은 차폐용 접지를 시공하기 위해 적용하는 접지저감재를 활용한 보링접지 시공기술에 관한 것으로 접지저항 산출방법과 산출식에 필요한 파라메터와의 관계 등을 실제 시공결과와 비교하며 분석하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.3
• /
• pp.169-173
• /
• 2015

This study is to predict the life exponent by measuring, over 7 years, the insulation resistance of high-voltage cables in 22 kV operation for 13 years. We found out the lifetime index in order to determine the time-dependent trend of deteriorating performance of power cables. The insulation resistances decreased according to elapsed time. We found that: the initial measurements of the cable systems were in agreement with the deterioration properties of the Arrhenius Law. By analyzing the life curve of the cable system, we also verified that the value of the life exponent (n) in the v-t characteristics defined by Weibull distribution has values from 10 to 11. When designing the cable system, the initial value of life exponent was chosen as 9 without any grounding. We have verified that the theoretical grounding based on the design safety of n=9 was actually the best one available. In the short term, we apply our research result to the diagnosis and evaluation of the power cables. In the long run, however, we plan to reduce the cost of the installation and management of cable systems in operation at power stations.

• 정보화사회
• /
• s.98
• /
• pp.60-61
• /
• 1996

1962년 한국케이블공업주식회사로 설립된 LG전선은 금성사와 금성전선, 그리고 1995년 지금의 LG전선으로 이름을 바꾸면서 30여년동안 국내 전산산업을 주도해 왔다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.2 no.4
• /
• pp.17-25
• /
• 1991

Slotted coaxial cables are used for a wide variety of radio communications and control applications within buildings, subways, tunnels and outdoors. They function as continuous antennas to solve RF coverage problems in difficult or confined areas. In this paper the electric and magnetic field distributions inside and outside of axially slotted coaxial cables are analyzed numerically. This paper gets the fields from the equivalent potentials which are obtained by grid relaxation method. The slot electric field configurations are consistent with Essam E. Hassan's results. The field distributions in the slotted coaxial cables show that the TEM mode doesn't propagate any longer in them. But the fields don't variate with the frequencies that are under the first higher order mode cutoff frequency of shielded coaxial cable of the same dimension The fields inside of the tunnel ($3\times4$) including the slotted coaxial cable axially are similar to those of $TE_{10}$ mode at 38.75 MHz. This method offers the basis for theoretical analysis of coaxial cables with nonuniform slots as well as coaxial cables in tunnels and buildings.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.9 no.2
• /
• pp.73-81
• /
• 2004

Voltage induced by the Tsushima Current on an abandoned submarine telephone cable has been measured since March 1998 in order to monitor the volume transport through the Korea Strait. Voltage has a good linear relationship with the transport measured by bottom-mounted Acoustic Doppler Current Profilers (ADCPs) along a section spanning the Korea Strait. This paper reviews researches using submarine cables briefly; we introduce the method to measure voltage on submarine cables, present some results focusing on the example of the Korea Strait, and mention the future prospect to use other submarine cables around Korea.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.4
• /
• pp.205-211
• /
• 2014

With a development of modern industry, demand for electric power is rapidly increasing and the capacity of power transfer is required to become bigger and bigger. At power station, the high-voltage power cable is used as the only method in order to transfer electric power. In this paper, we have analyzed the deterioration characteristics of 6.6kV power cable systems in operation. For the time duration of 2000 days, we have measured the cable in operation in order to extract the data for the deterioration characteristics. By analyzing the data by means of several steps of filtering processes, we could obtain the linear relations of insulation resistances as a function of time. Furthermore, we can verify that the progress characteristics in deterioration process of 6.6kV power cable systems follows the process of heat deterioration.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.1
• /
• pp.227-232
• /
• 2016

As the demand for electric power increases, all devices operating in power stations and all devices adopted in order to deliver distant loads need to be operating in perfect condition at the level of reliability expected by consumers. In general, the lifetime of cables used in delivering high power is declared to be 30 years from the time of production. Deterioration (which is the worsening of electric properties) starts from the very moment of operation. In spite of the reduction in reliability caused by deterioration, the reality is that cables often operate at considerable risk of accidents because the reliability of operation has not been diagnosed. We have invented a device to diagnose the deterioration processes of high-voltage power cables. It has been installed and is currently operating at Korea Western Power Co., Ltd., located in Chungnam, Korea. In previously published papers we have shown graphs obtained by plotting insulation resistances versus time, through analyzing the data extracted from operating cables using the devices we have invented. In this paper, we verify that the previously plotted graphs agree with the life time index of Weibull distribution of probability.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.6
• /
• pp.1069-1076
• /
• 2007

DOCSIS 3.0 protocol are proposed to support high-speed cable network DOCSIS 3.0 MAC protocol regulates CM and CMTS channel transfer times through MAP message. So MAP Inter-arrival time is primary factor of network performance. However, standards does not include the details of MAP Inter-arrival Time affecting the performance of MAC protocols for DOCSIS 3.0. In this paper, we evaluated the performance of DOCSIS 3.0 protocol follow in MAP Inter-arrival Time. Based on the evaluation results, we propose the optimal MAP Inter-arrival Time. We found that the protocol shows best performance when the MAP Inter-arrival Time is 0.05sec. The research results can apply to performance element which important for the construction of DOCSIS 3.0 base cable networks.

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

• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.11a
• /
• pp.517-518
• /
• 2009

HDTV의 보급과 디지털 방송이 보편화 되면서 디지털 영상에 대한 기술이 점차 발전하고 있다. 지상파, 위성, 케이블 방식으로 수신 하고 있는 디지털 방송은 케이블 선으로 수신 되는 방송을 하나의 영상장치에서 밖에 볼 수 없는 불편함이 생긴다. 본 논문에서는 가정 또는 공공장소에서 디지털 영상을 여러대의 TV 또는 PC 등의 하드웨어에서 각각의 원하는 채널을 볼 수 있고 사용자간의 정보를 공유할 수 있는 시스템을 설계 및 구현 하였다.