• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.215-218
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• 2013

This paper proposes the effective method to improve the protection from induced lightning surge by making common grounding from individual grounding. Common grounding under equipotential principle is more effective than individual grounding for lightning surge protection, and so common grounding is indicated as international technical standard under the AC power supply system with neutral line. So, this paper is to propose the effective way of induced lightning surge protection method for currently installed power supply system which has no neutral grounded line and individual grounding which are weak for lightning surge protection. This proposal can improve the power supply system as has neutral line, and improve the grounding system to common grounding system. And also this paper proposes to make effective equipotential system with voltage variable shunting devices for lightning surge protection.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.3
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• pp.306-314
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• 2012

This paper proposes a new system to maximize efficiency of Air Base Protection Operations through the development of location identification software. The Wibro-based location identification system for Air Base Protection Force offers Blue Ground Force digitalized character message which is not exposed to enemy. Also, it is possible to automatically provide the location of Blue Ground Force to Air Base Ground Operations Center. The test result proves that this system is very helpful when Air Base Protection Force executes Air Base Protection Operations.

• The Journal of Fisheries Business Administration
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• v.1 no.1
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• pp.1-18
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• 1970

The fishermen around fishing villages have organized the Eo Chon Gae, a co-operative organization based on the Fisheries Co-operative Law. The Eo chon Gae plays a vital role in the fishing village community, and the common economic, administrative and social profits are expected by members. The members of the Eo Chon Gae must work together in a common coastal fishing ground, this fishing ground is jointly owned by the community, and the members have to conduct the Eo chon Gae jointly for their common profit. This system, as mentioned above, is called the Eo Chon Gae, which is generally called a fishing village community, or a fishing administrative community. The purpose of these theses is to consider what kind of character and principles the Eo Chon Gae has. The contents of these theses are divided into six parts: 1. The various concepts of the fishing administrative community 2. The progress of the Eo Chon Gae. 3. The organization of the Eo chon Gae. 4. The purpose of the Eo chon Gae. 5. The work of the Eo Chon Gae. 6. Types of the Eo Chon Gae.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.258-261
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• 2009

This paper proposes an earthing system without ground connection. As a Green IT Environmental Solution, Internal-external surge and other unnecessary electric currents are converted into energy and through a discharge the signal is reduced. It's a structure that discharges through a neutral electric transformer. The results show that the electric potential rising of the earthing system proposed in this paper are approximately below the half and the discharge currents increased approximately 9 times when compared to existent earthing systems. This earthing system is economical, easy to install and can solve environmental contamination.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.740-741
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• 2007

This paper analyses the transient state of underground distribution system against single line to ground fault in underground transmission systems, when underground transmission systems and distribution systems are made of common grounding. Underground transmission systems and distribution systems are modeled by EMTP/ATPDraw. Simulation is carried out considering variation of parameters such as value of common grounding, balance load and unbalance load.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.56-64
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• 2008

Although the EGSE (Electrical Ground Support Equipment) and MCS (Mission Control System) have many similar or even identical functions, the EGSE used for assembly, integration and validation phase and the MCS for the mission operations phase are normally developed separately and used by different groups of engineers. However, the common ground system for EGSE and MCS has developed and many space missions such as PROBA (PRoject for On-Board Autonomy), ROSETTA, MARS EXPRESS, CRYOSAT (Cryosphere Satellite), GOCE (Gravity field and steady state Ocean Circulation Explorer), and GALILEO have used or will use it to minimize risk, reduce cost and improve overall product quality. It is based on ECSS (European Cooperation for Space Standards) E70 which is the international standard for ground systems and operations published by ECSS E70 Working Group. The ECSS E70 contains the basic rules, principles and requirements applied to the engineering of the ground systems and the execution of mission operations. This paper introduces standardization policy, organization and standard documentation in ECSS. The overview of ECSS E70 such as status, purpose and contents is also described in this paper.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.5
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• pp.265-270
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• 2006

In this paper EMI problems with induction motor drive system using multi-level inverters are investigated. The high power multi-level inverter usually operates with low switching frequency and produces large noises. Generally, EMI consists of the conduction component through source lines and emission component emitted to the space. This conduction component can be classified to the common-mode between source line and ground, and the normal-mode between lines. The EMI filters for the induction motor drive system are designed and implemented to reduce EMI noise. Finally the designed system is verified by the experiment. The experimental results show that both the normal mode and common mode noises are greatly reduced compared to the system without filters.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.245-249
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• 2007

The tendency of lightning surge to propagate displays the difference for applicable power and equipment. However, looking into the subject equipment with the lightning surge, the lightning surge can be divided in between the two lines of power, between the power line and the ground, the power line and the PE conductor, between the neutral line and the ground and the like. In addition, in the event of the communication equipment, there exists the case of lightning surge entered from the power line in addition to the entry between the communication lines, the communication line and the ground. In this study, the tendency of propagation of lightning surge penetrated on to the subject equipment is analyzed through the empirical experiment in accordance with the ground method by using the independent ground, common ground, bypass arrester and others among the techniques for safety improvement in power lines.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.167-174
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• 2016

The Korean distribution line currently consists of overhead ground wires (OHGW), overhead distribution lines, neutral wires (NW), and messenger wires (MW). The MW is installed under the NW. The lightning protection system in Korea is focused on OHGW and lightning arrester and the MW are not considered. Therefore, this paper proposes the applicability of MW for purpose of lightning protection. For this, we analyzed the effects of lightning overvoltage according to the existence of OHGW and MW and the grounding conditions of the MW in the Korean distribution system. The grounding conditions of the MW that we took into consideration were the common or separate grounding of the MW and NW. The analysis based on the equivalent circuit of the distribution pole at each condition was performed. The distribution lines and lightning were modeled using the Electromagnetic Transients Program (EMTP). For each of the installation conditions of the OHGW and MW, the various lightning conditions were simulated and analyzed for both direct and indirect lightning. The simulation results showed that, if the OHGW was not installed in the Korean distribution system, the lightning overvoltage could be reduced by the common grounding of the MW and NW.

• The Journal of Fisheries Business Administration
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• v.29 no.2
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• pp.21-46
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• 1998

The government is largely responsible for preventing “the tragedy of the common property”, but fisherman's effort fer an autonomous fishery control is equally required. Especially in these days of EEZ such self- regulated fishery management system should be developed and cared for as well. This study aimed to explore a proper management system for coastal fishing ground that now requires the responsible fisheries management by investigating and analysing more drastically the managerial functions of fishery right by Eochon-Gye(the smallest unit of fisheries cooperative based on a fishing village), a typical fishery producer's organization in Korea. This study also included such contents as (1) an understanding of fishery producer's organization, (2) the utilization and management system of coastal fishing ground, (3) the actual condition of fishing right distribution in Korea, (4) the fishery right management and activity of Eochon-Gye, (5) the operation and distinctive feature of fishery right in Japan, (6) the intervention and limit of fishery producer's organization for fishing ground management function, and (7) summary and proposal. We made all Eochon-Gye of the whole country an object of this study and carried out an investigation into Eochon-Gye through a questionnaire. We extracted 359 Eochon-Gye, 20% of the total 1,719 Eochon-Gye as a random sample and investigated these regions through a questionnaire by mail. The contents of the questions consist of 40 items, including six categories about the organization of eochon-gye, and fishing ground management and activities.