• Journal of electromagnetic engineering and science
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• v.7 no.2
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• pp.83-90
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• 2007

In this paper, the formulation of the protection ratio based upon a composite fade margin and availability is newly presented for the detailed planning of frequency coordination in the microwave relay system network, and computed results for co-channel and adjacent channel protection ratios are illustrated over an actual system with 6.2 GHz. It is shown that the protection ratio to assure a quality of service can be expressed in terms of the composite fade margin, noise-to-interference ratio, net filter discrimination, and system parameters. In addition, the net filter discrimination, depending upon the transmitter spectrum mask and the overall receiver filter characteristic, has been examined to investigate the effect of the adjacent channel protection ratio caused by the adjacent channel interference. Regarding simulated results for 6.2 GHz, 60 km, 64-QAM, and N/I=6 dB at the bit error rate of $10^{-6}$, composite fade margin and co-channel protection ratio yield 25.14 and 50.3 dB, respectively. Also, the net filter discrimination of 26.5 dB and the adjacent channel protection ratio of 23.8 dB are obtained at the first adjacent channel of 30 MHz. The proposed method provides some merits in view of a comprehensive and practical application with more detailed and various system parameters needed to access the criteria for making the proper frequency coordination.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.4 s.23
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• pp.21-28
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• 2006

This research analyzed the operational status of fire protection system managers who execute self inspection of the fire equipment in the specific fire protection facilities and presented the improvement scheme. Being made up inquiry for job environment, institutional environment, and operational environment for the subject of fire protection system managers who execute self inspection to complement the fire equipment inspection by city public fire protection service, the issues of the operational status of the institution of fire protection system managers were positively understood. The research result showed the conflict among building owner, fire equipment inspector, and fire protection system manager was existed due to the legal and institutional inertia to the self inspection, so it is judged that mutual complementary and cooperative relation should be established.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1818-1823
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• 2015

In this paper, we analyzed the optimal configuration of protection wire that have been installed in the electric railway power supply system. Protection wires are to suppress the ground potential rise when the short circuit fault between contact wire-rail(C-F), and protect the electronics equipments(signalling and communication) that are facility the wayside. The role of protection wires must be feed back quickly the fault current to the substation when a short circuit fault occurs. In this paper, we proposed that only one line to install the protection wire. Comparing how to newly proposed and existing system, most of the performance is similar. The reason is that most of the current flowing in the protection wire near the location where the fault occurred. There is no problem even if in one line for human safe and the low impedance of the return circuit in dimension to ensure the safety of the facility during the fault. To ensure safety during an fault occurs, it is sufficient even by one line. But, In the protection wire of facilities planning it is necessary to design taking into account the potential utility.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1212-1216
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• 2014

This study aims to find out the best anode location for buried pipelines. Numerical simulation program known as CATPRO (Elsyca, Belgium) were used for confirming the best location of anodes and the effects of impressed current cathodic protection system. Applied conditions for numerical simulation were similar to on-site environmental conditions for optimal application of cathodic protection system. Used criterion of cathodic protection was NACE SP 0169, which describes that minimum requirement for cathodic protection is -850mV vs. CSE. Various layouts for anodes' installation were applied, which were distance between anodes, anode installation location, and applied current. The areas where cathodic protection potential was lower than -850mV vs. CSE was limited up to 50m from anode installation locations. It was founded numerical analysis obtain cost-effective and efficient cathodic protection methods before design and application the impressed cathodic protection system to on-site environment.

• Korean Security Journal
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• no.6
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• pp.103-122
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• 2003

Protection sciences are new science. therefore, protection martial arts sciences are will studied be based on study of protection in order to supply high level by request. Moreover, It is reconstruction that protection martial arts masters education, systematic manage, certificate system, protection martial arts recognition certificate, protection martial arts equipment, practice of protection martial arts. Protection martial arts occurs on the unforeseen accident and body guarding, therefore martial arts concept of protection martial arts different general martial arts and sport. In order to develope of protection martial arts First, scientific thesis need of protection martial arts learning. Especially, aims of present protection martial arts is not protect oneself, protect the VIP to safely from all dangers is different thing with aims of general martial arts. Instinct that VIP protect rather than oneself should study and develop. Second, techniques and model of protection martial arts spread to who in connection with security service by systematic and organized. Preferentially, study of protection martial arts Techniques and model possible the protection martial arts learned society, found laboratory and endowed protection martial arts society organize and prevention for random of protection martial arts and must make the original protection martial arts. Third, protection martial arts official certificate and license system must organize in order to training and manage of protection martial art master, Match director(First Second), life physical director(First, Second, Third) is systematically manage by Ministry of Culture & Tourism Republic of Korea. Like this protection martial arts also classify the certificate by scholarship and experience. Fourth, In union to university, private security service company, public institution, police and system that possible leaning to protection martial arts certificate course important. In addition, destroy the commercial character of present martial arts and cultivate the pure martial arts mind, should develop to martial arts in order to improve the humanism and temperament of right body guard.

• Fire Science and Engineering
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• v.10 no.4
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• pp.37-42
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• 1996

The "Intelligent Fire detecting and Extinguishing System" is an up-to-date fire protection system for modern high-rise buildings, international airports, enormous industrial facilities, dome stadiums such as specific areas in which the application of our local fire protection regulation could not be satisfied. The state-of-the art initiating devices communicated with sophisticated network control panels enable peoples to get reliable and powerful suppressions using water or gas, providing absolute protection. The Intelligent Water Cannon System, the Low Pressure $CO_2$ System and the MXL Networking Fire Alarm System introduced in this paper accomplish the dynamic protection for the special hazards.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.8
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• pp.1286-1290
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• 2004

This paper describes the anti-corrosion system on underwater structures of ships. Metals and alloys have several positions in the series such as immunity, corrosion and passivity. The iron potential has to change from the corrosion position to the anodic protection or cathodic protection for preventing corrosion by providing corrosion protection system such as ICCP(Impressed Current Cathodic Protection). The purpose of ICCP system is to eliminate the rusting or corrosion, which occurs on metal immersed in water. The system includes a power supply unit, which consists of a transformer, a converter. a controller, etc. This paper presents the protection performance of ICCP under dynamic condition such as velocity. The variation of potential and current density with time and environment factors are also described Finally, the experimental results will be explained and analysed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.700-704
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• 2011

This paper proposes a coordinative protection study results of 22.9kV HTS(High-Temperature Superconducting) cable implemented distribution system. HTS cable can provide about 5 times larger transfer capacability compare to conventional XLPE cable, however, it has different heat characteristic so called quench. This paper presents the simulation results on Ichun substation HTS cable which connects main transformer and 22.9kV bus. Various expected fault cases are considered and discussed to examine whether conventional protection scheme is effective to protect both of existing facilities and HTS cable. With the results of simulation, conventional protection scheme can be used if instantaneous element and time inverse elements could be adjusted with proper time coordination. Internal temperatures of HTS cable conductor in safe region with proper protection without quench. This results are to be demonstrated by the field test and will be implemented in Ichon substation HTS cable protection and control system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1459-1467
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• 2011

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 Aerospace System Engineering
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• v.12 no.3
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• pp.79-85
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• 2018

The demand for the development of atmospheric entry vehicles, dealing with reentry and solar-system planet exploration, is increasing. Generally, atmospheric drag and heating accompany the entry into atmospheric air. Accordingly, the selection of the thermal protection materials and the design and application of the thermal protection system are very important. In this paper, the atmospheric entry environment and the type and characteristics of the thermal protection materials are discussed. The design and application status of a thermal protection system for spaceplanes are described.