• International Journal of Highway Engineering
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• v.19 no.3
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• pp.83-90
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• 2017

PURPOSES : In this study, systematic road snow-removal capabilities were estimated based on previous historical data for road-snowremoval works. The final results can be used to aid decision-making strategies for cost-effective snow-removal works by regional offices. METHODS : First, road snow-removal historical data from the road snow-removal management system (RSMS), operated by the Ministry of Land, Infrastructure and Transport, were employed to determine specific characteristics of the snow-removal capabilities by region. The actual owned amount and actual used amount of infrastructure were analyzed for the past three years. Second, the regional offices were classified using K-means clustering into groups "close" to one another. Actual used snow-removal infrastructure was determined from the number of snow-removal working days. Finally, the correlation between the de-icing materials used and infrastructure was analyzed. Significant differences were found among the amounts of used infrastructure depending on snowfall intensity for each regional office during the past three years. RESULTS:The results showed that the amount of snow-removal infrastructure used for low heavy-snowfall intensity did not appear to depend on the amount of heavy snowfall, and therefore, high variation is observed in each area. CONCLUSIONS:This implies that the final analysis results will be useful when making decisions on snow-removal works.

• Journal of Institute of Convergence Technology
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• v.6 no.2
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• pp.25-28
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• 2016

Recently, due to the climate change by global warming, the amount of snow has increased. The situations were demanded to use many snow removal materials. The snow removal materials that used in Korea were solid chloride deicing material. That is calcium chloride($CaCl_2$) and sodium chloride(NaCl). Solid chloride baesd snow removal materials have various property, for example good freezing point depression, deliquescence and economical solvents. However, there are problems such as water pollution, high corrosiveness and ecocide. For such reason, development of eco-friendly deicer was required obligatorily. This study investigated development situation of eco-friendly deicer materials.

• 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.

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.5-17
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• 2012

The amount of snow due to global warming and climate change has recently increased. The effective management of snow removal materials will be required. First, on the basis of domestic winter temperature, it is not necessary to get a baseline to less than the freezing point of $-52^{\circ}C$ for the calcium chloride($CaCl_2$) of 30%.. In terms of cost comparison between calcium chloride($CaCl_2$) and sodium chloride($NaCl$), the calcium chloride($CaCl_2$) is 2 to 3 times more expensive, and the supply of the calcium chloride($CaCl_2$) is not produced in domestic country and is in the conditions that have to imports all needed. Accordingly, the effective use scheme of snow removal materials should be considered to multifaceted ways. Thus, the objective of this study is to develop effective method and to replace from calcium choride($CaCl_2$) to sodium chloride($NaCl$) solution in the current snow removal operating system that uses a pre-wetted salt spreading method. The effective method that equals to the quality of the existing snow removal materials was developed in this study through performance tests for deicing chemicals, corrosion test of steel and freezing and thawing tests of concrete.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.143-144
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• 2006

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.21-33
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• 2020

Purpose: The objective of this research is to classify snowfall area types with consideration of past regional snowfall characteristics and times for the effective local snow removal response systems of 229 local government districts. Method: This research first collected snowfall data of South Korea meteorological stations, and classified regional types using successive snowfall time. This research finally produced GIS maps using regional type information of snowfalls by applying GIS analysis methods. Result: This research provides five types of snowfall regions including 'frequent heavy snowfall regions', 'frequent light snowfall regions', 'rare heavy snowfall regions', 'average snowfall regions', and 'rare light snowfall regions' based on analysis results. Conclusion: Results of this research can be used as basic information for regional demand estimations of snow removal equipments, materials, vehicles, and personnel for the efficient snow removal response systems.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.66.1-66.1
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• 2011

반도체를 비롯하여 LCD, OLED와 같은 디스플레이 (FPD: Flat Panel Display) 분야는 국가 선도 사업으로써 발전을 거듭해오고 있다. 하지만 기술의 성숙도가 높아짐에 따라 최근 중국과 대만 업체와의 경쟁이 심화되고 있으며, 더불어 환경문제가 큰 이슈로 떠오르고 있어 신기술 개발을 통한 생산 수율 향상 및 친환경 공정 개발의 중요성이 커지고 있다. 반도체, 디스플레이 공정에서 생산 수율 저하의 주요 원인으로써 공정 중 발생하는 미세 오염 입자를 들수 있다. 반도체 및 디스플레이 공정에서 세정 기술은 전체 기술의 30% 이상을 차지하며 생산 수율 및 제품의 품질에도 큰 영향을 주는 공정이다. 세정 공정은 일반적으로 습식 세정 공정이 낮은 공정비용을 바탕으로 널리 적용되어 왔으나, 기판의 대형화와 패턴의 미세화에 따라 정밀한 세정 스펙이 요구되며 더불어 막대한 양의 초순수와 화학액의 사용으로 인한 공정비용 증가와 환경 규제 강화에 따른 폐수 처리의 문제에 직면하고 있다. 이에 따라 폐수의 양을 줄이며 건조공정을 필요로 하지 않아 공정비용을 줄일 수 있는 건식 세정 공정에 대한 연구가 활발히 진행 되고 있다. $CO_2$ snow jet 세정 기술은 건식 공정으로써 $CO_2$ 가스를 특수하게 제작된 분사 노즐에서 고압으로 가스를 분사하여 이 때 발생되는 순간적인 감압에 의한 단열 팽창으로 생성된 $CO_2$ snow 입자가 기판 표면의 오염물과 물리적 충돌을 하어 세정이 이루어지는 기술이다. 특히 $CO_2$ 세정은 환경과 인체에 무해하며 공정 후 바로 승화하기 때문에 추가적인 폐수처리 공정 등이 필요하지 않고, 건식 공정으로써 수세(Rinse) 공정을 필요로 하지 않기 때문에, 공정비용을 크게 줄일 수 있으며 물반점 발생을 방지 할 수 있는 친환경 건식 공정으로써의 장점을 가지고 있다. 본 연구에서는 자체적으로 개발한 $CO_2$ snow jet을 바탕으로 하여 다양한 공정조건을 변화시켜 세정효율을 측정하는 한편, 최적화 하기 위한 연구를 진행하였으며 더불어 $CO_2$ snow의 세정력을 정량적으로 평가하기 위한 연구를 진행하였다. 실험을 통해 가장 효과적으로 $CO_2$ snow 입자를 배출 할 수 있는 공정 조건으로써 5 bar의 캐리어 가스 압력을 사용하여, 세정력에 가장 큰 영향을 줄 수 있는 분사 노즐과 기판 사이의 거리 및 분사 노즐의 각도 등을 변화시켜 각 조건에 따른 세정효율을 평가하였다. 세정 오염물은 Silica, PSL 표준 입자(Duke scientific, USA)를 정량적으로 웨이퍼에 오염 시킨 후, 파티클 스캐너(Surfscan 6500, KLA-Tencor, USA)를 이용하여 세정 전 후의 오염입자 개수 변화를 통해 정량적으로 세정효율을 평가하였다. 본 연구를 통하여 $CO_2$ snow jet를 이용한 친환경 고효율 건식 세정 공정 메커니즘을 분석하였으며, 노즐과 기판 사이의 간격 및 분사 노즐의 각도 등을 최적화 한 세정 공정을 얻을 수 있었다.

• Journal of the Korean GEO-environmental Society
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• v.19 no.12
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• pp.59-64
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• 2018

The damages to the reinforced earth retaining wall are divided into the front wall, foundation, drainage and upper slope. Damage of reinforced earth retaining wall is mainly caused by damage caused by drainage problem in the field. Recently, damage caused by snow removal materials have been occurred. Recently, the amount of snow removal materials used in winter is increasing due to abnormal weather. This chlorides degrades the concrete structure, where the reinforced earth retaining wall was no exception. There has recently been a case in which the front wall of the reinforced earth retaining wall deteriorates due to the chlorides introduced into the back filling portion through the drainage passage. Therefore, in this study, the cause of damages of reinforced earth retaining wall constructed in bridge abutment was analyzed, and an analytical study was conducted on the countermeasure. As a result, it was found that chlorides, which was introduced through the drainage system in the expansion joint of the bridge shift part or the upper structure, is infiltrated into the back part of the reinforced earth retaining wall and damaged. Therefore, it is suggested to improve the drainage system and restored the stiffness of the front wall.

• Corrosion Science and Technology
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• v.22 no.5
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• pp.322-329
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• 2023

There are a variety of heat exchangers used in automobiles, such as shell and tube heat exchangers, double tube heat exchangers, and plate heat exchangers. Most of them are water-cooled to prevent engine overheating. There have been reports of corrosion damage to these heat exchangers due to continuous wetting caused by external temperature differences, road pollutants, and snow removal. In addition, galvanic corrosion, which occurs when two dissimilar materials come into contact, has been identified as a major cause. In this study, corrosion characteristics and galvanic corrosion behavior of Al alloy (AA3003, AA4045 and AA7072) used in automobile heat exchangers were analyzed. Effective clad materials for heat exchanger tubes and fins were also evaluated. It was found that AA7072 should be applied as the cladding material for fin AA3003 and that AA4045 was suitable as a cladding material for tube AA3003 because this clad materials application was the most effective clad design to delay the occurrence of pinhole in the tube. Main factors influencing galvanic corrosion dissolution were found to be galvanic corrosion potential difference and galvanic corrosion current density.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.spc
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• pp.61-67
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• 2023

Special equipment used for snow removal is only used in the winter and must be moved into storage during non-winter seasons. However, when moving heavy equipment using a forklift within a limited space, safety accidents may occur due to deformation and damage due to the worker's limited visibility and excessive loading of heavy objects. In this study, the scissors boom of the developed heavy load transporter was conducted in two cases: link structural analysis and position-based structural analysis. In detail, the link structural analysis covers four cases of stress and safety factor according to material and thickness to optimize the specifications of the material selected during development, and the structural analysis according to position covers two cases before and after the lift, when maximum stress concentration is achieved. Safety was evaluated through finite element analysis. As a result of the study, when manufacturing a scissors boom type heavy load transporter that can withstand a load of 10 tons, the link showed safety at SS400 4.5mm or higher, and reinforcement is needed in the upper and lower structures, so it is judged to be useful in applying materials according to the load.