• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.237-243
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• 2006

Deicing system is to melt frost or ice freezed in catenary line when the temperature is lower than $0^{\circ}C$ in winter. The principle of deicing system is to melt frost or ice by Joule heat of catenary impedance. The performance of deicing is dependant of deicing current determined by the length of deicing section, deicing impedance and current division ratio of catenary line and messenger line. So, we present technique for estimating deicing current and process for determination of deicing section in the conventional line. Deicing impedance is estimated using Carson-Pollaczek equation, and current division ratio of catenary line and messenger line is estimated using voltage drop, and deicing current is estimated using power system data of deicing system. For the determination of the final deicing section, we verified estimated value comparing with experiment value of deicing impedance and current division ratio of catenary line and messenger line using low voltage experiment. Finally, we verified the validity of estimation technique and process using a simulated test data of real deicing system operation in the Chungju Substation, Chungbuk line.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.288-290
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• 2005

Deicing system operated in high speed line is to melt frost or ice freezed in catenary line when the temperature is lower than 0 in winter. The principle of deicing system is to m디t frost or ice by Joule heat of catenary impedance. The performance of deicing is dependant of deicing current determined by the length of deicing section, deicing impedance and current division ratio of catenary line and messenger line. So, We present technique for estimating deicing current in convention line. Deicing impedance is estimated using Carson - Pollaczek, current division ratio of catenary line and messenger line is estimated using voltage drop, and deicing current is estimated using power system data of operation secion for deicing system in this technique. To verify the validity of technique, we compare the estimated current using technique of this paper with deicng current of high speed line.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.782-788
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• 2003

Making deicing countermeasure plan against snow accretion on power line is a very complicated problem, which should take into account both the possibility of accidents due to snow accretion on power line and the stable operation of power system. As knowledge engineering can be a good solution to this field of problems, a prototype expert system to assist power system operators in forecasting snow accretion on power lines and making a list of all the feasible and effective deicing countermeasures has been developed. The system has been remodelled into a fuzzy expert system by adopting fuzzy rulebase and fuzzy inference method to systematically process the fuzziness included in the heuristic knowledges. Simulation results based on the past snow accretion accident data show that the proposed system is very promising.

• Journal of Aerospace System Engineering
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• v.7 no.3
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• pp.51-57
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• 2013

This study describes the Federal Aviation Administration(FAA) certification policy for approving the use of Type II, III, and IV deicing/anti-icing fluids on small category airplanes. These fluids can be characterized as non-Newtonian, pseudo-plastic fluids, also known as "thickened" fluids. Deicing fluids are used before takeoff to remove frost or ice contamination, while anti-icing fluids are used before takeoff to prevent frost or ice contamination from occurring for a period of time(referred to as "holdover time") after application. Thickened deicing/anti-icing fluids can affect airplane performance and handling characteristics and their residue may cause stiff or frozen flight controls. This study also describes an approval process that may be used by type certificate holders and applicants for a type certificate under parts 23 to support operational use of these fluids on their airplanes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.95-102
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• 2003

To Prevent the damage of power system facilities by snow accretion on transmission lines, a prototype expert system has been developed. The system has the basic functions of forecasting snow accretion on transmission lines and making a list of all feasible and effective deicing countermeasures to assist power system operators. As estimating of snow accretion on power lines and making countermeasure plans are very difficult to solve analytically, knowledge engineering can be an effective method for this problem. The heuristics about the effect of weather conditions on the snow accretion process on power lines and power system operation for the deicing constitutes main nile base. Simulation results based on past snow accretion accident data show that the proposed system is very premising.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.51-59
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• 2016

OBJECTIVES : The objective of this study is to estimate the appropriate storage required for deicing materials in Gangwon-do for successful snow removal operations during the 2018 Pyeongchang Winter Olympic Games. The final estimates of the deicing chemicals can be used by public agencies to aid decision making. METHODS : First, the database that exists in the road snow-removal management system (RSMS) of the Ministry of Land, Infrastructure, and Transport, South Korea was used to determine historical characteristics of snow removal experiences in Gangwon-do. The database includes historical information, including regional and road weather data and number of snow-removal works. Second, both the maximum and the actual amount of storages used for deicing materials in the past three years were analyzed. Lastly, the final estimates of the deicing materials were evaluated using an additional equation. It considers frequency of salt spray application, total administrative road length estimated by road agencies, and number of days required for snow removal works in Gangwon-do. Consequently, the results show that significant differences were not observed between the final estimates and the maximum amount used during the past three years. RESULTS : The final estimates of the deicing materials are almost similar to the maximum amount used during the past three years in Gangwon-do. CONCLUSIONS : The study shows that the estimates of deicing chemicals can be useful when decision making is required for the snow-removal policy.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.11-18
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• 2015

PURPOSES : The purpose of this study is to develop a deicing pavement system using carbon fiber or graphite with high electrical conductivity and thermal conductivity. METHODS: Based on literature reviews, in general, conventional concrete does not exhibit electrical and thermal conductivity. In order to achieve a new physical property, experiments were conducted by adding graphite and carbon fiber to a mortar specimen. RESULTS: The result of the laboratory experiment indicates that the addition of graphite can significantly reduce the compressive strength and improve the thermal conductivity of concrete. In the case of carbon fiber, however, the compressive strength of the concrete is slightly increased, whereas, the thermal conductivity is slightly decreased against the plain mortar irrespective of the length of the carbon fiber. In addition, a mixture of the graphite and carbon fiber can greatly improve the degree of heating test. CONCLUSIONS : Various properties of cement mortar change with the use of carbon fiber or graphite. To enhance the conductivity of concrete for deicing during winter, both carbon fiber and graphite are required to be used simultaneously.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.139-148
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• 1993

Thermosyphons are simple devices that can passively transport thermal energy over relatively long distance with little temperature degradation. These attributes permit the use of low grade thermal energy for thermal control of structures including the snow melting and deicing to the pavement surface. The thermosyphon system requires no costly energy input and Is completely maintenance free. This paper presents the experimental results of the snow melting system in which thermosyphon was utilized to transfer the geothermal energy to the pavement to obviate slipping traffic accidents due to freezing of pavement in winter.

• Journal of People, Plants, and Environment
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• v.23 no.6
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• pp.625-636
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• 2020

Background and objects: Soil contamination caused by CaCl₂ that is used to deice slippery roads in winter is now recognized as one of the major causes of damage of roadside plants. The aim of this study is to identify the salt mitigation effects of planting Chrysanthemum zawadskii and using a soil conditioner. Methods: The study was conducted at the site where Pinus densiflora f. multicaulis was planted on the roadside between Konkuk University Sageori and Danwol Samgeori located in Chungju-si. We classified the soils collected from the field experimental site according to the degree of the damage caused by deicing agents and divided the site into six blocks of three 80 × 80 cm plots replicated by treatment type. Three selected plots were treated with loess-balls on the soil surface (high salinity with loess-balls, medium salinity with loess-balls, low salinity with loess-balls) and three were left as an untreated control (H = high salinity, M = medium salinity, L = low salinity). The soil properties were measured including pH, EC and exchangeable cations as well as the growth of Chrysanthemum zawadskiia. Results: In the results of soil analysis, pH before planting Chrysanthemum zawadskiia was 6.39-6.74 and in September, five months after planting, the acidity was reduced to 5.43-5.89. Electrical conductivity (EC) was measured to be H > M > L with the higher degree of damage by deicing agents. The analysis of deicing exchangeable cations showed that the content of Ca²⁺ of soils were significantly correlated to deicing exchangeable cations (Ca²⁺, Na⁺, Mg²⁺) in the shoot part of Chrysanthemum zawadskii. The loess-ball treatment showed a lower content of deicing exchangeable cations than the treatment where Chrysanthemum zawadskiia was planted. Conclusion: In this study, the use of a new system made of loess-balls is proposed as a soil conditioner to protect soils from the adverse effects of road deicing salts. These data suggest that treatment of soil conditioners and planting Chrysanthemum zawadskiia are effective in mitigation of salt stress on the soils damaged by deicing agents.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.6
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• pp.512-515
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• 2019

Overhead contact systems (OCS) consist of contact and messenger wires, in which the contact wire supplies electric energy to the railway vehicle by contacting a pantograph. However, this mechanical contact is interrupted during frosts or temperatures below $0^{\circ}C$ in the winter. In these conditions, railway vehicle accidents can occur during operation because of the low energy efficiency that results from the increase in the arcing between the contact wire and pantograph. Therefore, the detection of frost or freezing temperatures is necessary to maintain the stable operation of these trains. In this study, we proposed the development of a frost or freezing condition monitoring system on the OCSs that utilizes wireless communication.