• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.178-179
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• 2014

Corrosion is very serious problem in RC structure under ocean environment. There is no enough experiment information using the reinforced geo polymer concrete applied by electo chemical protection system. Three condition, such as tidal zone, submerged zone and crack were simulated to geo polymer specimen. Corrosion rate and natural electrode potential were measured through accelerated test. Anti corrosion property of geo polymer was better than OPC regardless of specimen condition and applied time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.8
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• pp.1113-1118
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• 2018

Protection in HVDC(High Voltage Direct Current) have the very fast velocity of fault detection. Because Fault in HVDC has the fast propagation, large currents, high interruption cost. The focus to velocity caused possibility of errors like a detection error like a high impedance fault. In this paper, Proposed complex composition for get the reliability and velocity. That used SFCL(Super Conducting Fault Current Limiter), Protection Zone and DTS(Distributed Temperature Sensing). The SFCL was detect the fault by quench and DTS&Protection Zone were perceive the detect by variation too. To examine the proposed method, PSCAD/EMTDC simulated. The results of simulation, proposed methods could the detect of fault to whole HVDC line. And that improved the reliability of fault clearing.

• The Journal of Korean Association of Computer Education
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• v.20 no.6
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• pp.95-104
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• 2017

The damage caused by information spill, forgery, falsification, and deletion by cyber infringement in educational institutions and universities is very large. In this study, we analyzed the types, causes, and problems of cyber infringement in educational administrative institutions and universities. As a result, administrative, physical and technical information protection activities were weak. In this paper, we propose a security enhancement method for each domain by dividing them into Internet zone, network-neutral zone (DMZ: Demilitarized Zone), general server zone, internal server zone (Server Farm), and user zone so that these vulnerabilities can be easily identified, supplemented or security enhanced. In addition, we have proposed a method to apply security information system architecture and information protection technology correctly for educational administration institutions and universities. This study is meaningful not to provide conceptual guidance but to suggest specific action and procedure oriented security management plan.

• Progress in Superconductivity and Cryogenics
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• v.23 no.4
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• pp.19-24
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• 2021

The low normal zone propagation velocity (NZPV) of high-temperature superconducting (HTS) tape leads to a quench protection problem in HTS magnet applications. To overcome this limitation, various studies were conducted on HTS coils without turn-to-turn insulation (NI coils) that can achieve self-protection. On the other hand, NI coils have some disadvantages such as slow charging and discharging time. Previously, the HTS coils with turn-to-turn insulation (INS coils) were operated in power supply (PS) driven mode, which requires physical contact with the external PS at room-temperature, not in persistent current mode. When a quench occurs in INS coils, the low NZPV delays quench detection and protection, thereby damaging the coils. However, the rotary HTS flux pump supplies the DC voltage to the superconducting circuit with INS coils in a non-contact manner, which causes the INS coils to operate in a persistent current mode, while enabling quench protection. In this paper, a new protection characteristic of HTS coils is investigated with INS coils charging through the rotary HTS flux pump. To experimentally verify the quench protection characteristic of the INS coil, we investigated the current magnitude of the superconducting circuit through a quench, which was intentionally generated by thermal disturbances in the INS coil under charging or steady state. Our results confirmed the protection characteristic of INS coils using a rotary HTS flux pump.

• Fire Protection Technology
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• s.11
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• pp.31-39
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• 1991

As the Present industry is developing, a structure and systems is tending increase. Therefore, the accident of freezing become intensified in our country, the continental climate zone of region in the middle degree. This paper is to analyze about the reason of freezing, principles to help avoid freeze, and so forth.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.37-44
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• 2004

This paper represents a new approach for the protective relay of power transmission lines using a Artificial Neural Network(ANN). A different fault m transmission lines need to be detected classified and located accurately and cleared as fast as possible. However, The protection range of the distance relay is always designed on the basis of fixed settings, and unfortunately these approach do not have the ability to adapt dynamically to the system operating condition. ANN is suitable for the adaptive relaying and the detection of complex faults. The backpropagation algerian based multi-layer protection is utilized for the teaming process. It allows to make control to various protection functions. As expected, the simulation result demonstrate that this approach is useful and satisfactory.

• Transportation Technology and Policy
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• v.13 no.6
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• pp.53-59
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• 2016

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.397-408
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• 2004

Due to the growing impact of non-point source pollution and limitation of water treatment technology, a new policy of water quality management, called a source protection, is now becoming more important in drinking water supply. The source protection means that the public agency purchases the pollution sensitive area, such as riparian zone, and prohibit locations of point and non-point sources. Many studies have reported that this new policy is more economical in drinking water supply than the conventional one. However, it is very difficult to determine location and size of the pollution sensitive zone in the watershed. In this paper, we presented the scientific criteria for the priority of the pollution sensitive zone, along with a case study of the upstream watershed of the Paldang Reservoir, Han River. This study includes applications of the analytical hierarchy process(AHP) and a watershed-based land prioritization(WLP) model. After major criteria affecting water quality were selected, the AHP and geographic analysis were performed. The WLP model allowed us to include both quantity and quality criteria, using AHP as the multi-criteria method in making decision and reflecting local characteristics and various needs. By adding a travel-time function, which represents the prototype effectively, the results secured adaptability and scientific objectivity as well. As such, the WLP model appeared to provide reasonable criteria in determining the prioritization of land acquisition. If the tested data are used with a validated travel-time and AHP method is applied after further discussion among experts in such field, highly reliable results can be obtained.

• Journal of Environmental Policy
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• v.2 no.1
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• pp.31-49
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• 2003

It is difficult to examine the causal relation of pollution damages because the time gap between pollution cause and effect is large and new pollutants are continuously being produced. Their many environmental effects are not promptly studied. As both the study of causal relation about pollution and the pollutant treatment are becoming highly advanced by the development of science and environmental technology, both the economy and balance on environmental regulation may be discussed. It is reasonable to decide environmental policy in consideration of close relation between both the generation and resolution of environmental problems and of technological developments because environmental problems are related to complicated social problems and scientific technologies. First item in policy decision about environmental control and management is preferentially to consider the way of prevention. It is necessary to prevent pollution by regulating the installment of environmental pollution facility into the environmentally sensitive areas, like water supply source and to regulate land utilization as a method to achieve pollution prevention. Second is a consideration of environmental technology development. This is a solution which can accomplish the development of environmental technology and the reinforcement of economic competition. Third is the coexistence of environment and economy. It is necessary to consider economy in connection with environmental problems and environment in economic problem. Then, we can enjoy a healthy life as well as economic affluence. Fourth is the enlargement of environmental management means. Environmental management means must be diversified because environmental cause and effect are varied. For Improving the land use regulation system, it is necessary to consider both land use regulation status and pollutant toxicity with the development of environmental technology. Land use must be approached by classifying land to 3 levels; water source protection zone and water front zone, special zone 1 and 2, rancus and other zones. Land regulation policy to prevent any accident in water source protection zone, waterfront zone, and special zone must be continuously upgraded. However, economical consideration in other zones is required by the development of environmental technology.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.131-142
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• 2009

The purpose of this study is to detect the protection area around the Geum-buk and Geum-nam Mountains for making a sustainable ecological network. The protection area in the Geum-buk and Geum-nam Mountains was analyzed by using spatial data and a field survey for landscape conservation purposes. A survey scope was fixed using digital elevation model, and the protection area was finally determined based on the parcel map called as the Korea Land Information System (KLIS). Here we have several conclusions in this study. First, spatial data used in this study were a map of ecological and natural degree (MEND), forest distribution map, elevation map, slope map, and several maps for the protection area assigned by laws regarding to the natural resources. Second, we used 4 alternatives to determine the best choice for showing the ecological network in the study area. One alternative (alt. 3) of 4 ones was finally chosen as the best condition for making the ecological network. The condition in elevation and slope was a little modified to a lower level in alt, 3. The result derived from alt, 3 reflected the continuity and connectivity in the ecological network and we estimate that the protection area can protect the core area using the buffer zone around the ecological network. Finally the parcel-based protection area in the Geum-buk and Geum-nam Mountains had $493.92km^2$ of the core area, and $233.99km^2$ of the buffer zone, which means the parcel-based protection area increased by $97.76km^2$ in the core area, but decreased by $76.61km^2$ as of in the topographical map.