• 한국도로학회지:도로
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• v.11 no.4
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• pp.37-44
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• 2009

• 한국도로학회지:도로
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• v.2 no.3
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• pp.46-57
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• 2000

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.41-49
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• 2009

Cement concrete pavement has become more common in Korean highway systems. However, as its service period increases, there are some technical problems occurs and no clear solution is available primarily due to the lack of active researches. This research, hence, aims to develop a new mix proportion that may provide better strength and durability with extended service life. Based on a variety of literature reviews, the experimental variables were determined as unit cement content, S/a ratio and W/C ratio. From the experimental works, it is recommended to increase the unit cement content up to 375kg/$m^3$, 400kg/$m^3$ and 425kg/$m^3$. The target slump and air content were set 40mm and 5%, respectively. The maximum size of coarse aggregate was decided to be 25mm because of the easiness of supply in the field. The reduction of W/C ratio was necessarily required and decreased to 0.4 which was proven not to cause any mixing problem with the increased unit cement contents along with polycarbon-based high range water reducing agent. In addition, it was known that the S/a ratio could be reduced to 0.34. The lowered S/a might be possible because of the increased cement paste and hence increased cohesiveness and workability.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.9-20
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• 2011

Most of domestic expansion joint system was applied by exposed expansion joint system. There are cases where it is damaged by driving. As the result noise and impact happened, and the social cost due to frequent repair works is increasing. So based on the Asphalt Plug Joint(APJ) system that applied in the United States and Europe, new buried expansion joint system was lately developed a system of Buried Folding Lattice Joint(BFLJ) that changed substructure. In this research, we have tested for durability and flexibility performance of buried expansion joint system that based on the type of asphalt mixture. Also we have evaluated for durability of BFLJ system against vehicle load using accelerated pavement testing. As a result of the experiment, the developed BFLJ system gives high flexibility performance and resolves transformation concentration along the joint section more than APJ system. Also it could be seen that the BFLJ system could overcome the disadvantages of APJ and prevent early damage. Because surface deflection of BFLJ system against vehicle load was measured low, and sub system in the buried expansion joint system was not damaged against vehicle load.

• Journal of Practical Engineering Education
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• v.11 no.1
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• pp.33-41
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• 2019

A pavement construction process consists of series of lay-down operation for pavement materials to form a designated thickness and compaction operation for the lay-down layer to form a designated strength. A technological breakthrough in pavement compaction equipment was made in last 15 years in western countries: intelligent compaction roller, that is equipped with GPS along with other pavement response sensors is becoming a game-changer in pavement construction. This paper introduces AR system that may be used in asphalt pavement compaction operation using intelligent compactor. Since AR technology is very new concept in road construction society, a suggestion for accompanying education program was also made for specific task group in pavement compaction operation. Since AR technology has not been introduced in asphalt pavement compaction operation, the AR compaction management would lead the construction quality of asphalt pavement to the beyond level.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.31-38
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• 2022

Due to the increasing consumer demands for the safety, shelf life, and quality of food, the application and development of active packaging in the food and packaging industry have been improved. According to the standards and specifications of the Republic of Korea for utensils, containers, and packages, the function of active packaging is to remove or alleviate factors that degrade food quality. Although extensive reviews regarding the development and commercialization of active packaging have been conducted, the legal regulations and safety assessments concerning active packaging have rarely been examined. This review provides information regarding the definition, structure, components, operational mechanisms, and applications for active packaging that actively removes oxygen, moisture, carbon dioxide, and ethylene. Furthermore, the legal regulations and research results related to the development of test methods for safety assessments of active packaging are investigated.

• Asian Journal of Turfgrass Science
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• v.12 no.3
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• pp.215-224
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• 1998

These experiments were conducted to compare the growth characteristics, cold and drought tolerances, disease tolerance and color of the 23 varieties of four different species of cool-season turfgrass introduced from the United States of America and Europe at Yonam College in 1995. Newport and Glade of 8 Kentucky bluegrass varieties were recorded better marks than others. Newport variety was recorded the good marks in the disease tolerance of summer seasons, uniformity, coverage and texture, but the bad marks in color, drought tolerance and rust tolerance and stay green of automn seasons. Glade variety was recorded the good marks in the disease tolerance of summer seasons, uniformity and coverage, but the bad marks in drought tolerance, texture and Pythium blight tolerance. Revel and Revel Jr of 5 tall fescue varieties were recorded better marks than others in color, shoot density, uniformity, coverage, and tolerance of Pythium and Fusarium blight disease. All of red fescue varieties died of disease for rainy season however texture was the finest of all the species in spring season. Dandy of 4 ryegrass varieties was recorded better marks than others in color, shoot density, coverage, drought tolerance and tolerance of Pythium and Fusarium blight disease but texture.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.859-869
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• 2008

These days, almost every industry's production line has become automatic and this phenomenon brought a lot of benefits such as increase in productivity and economical effect, assurance in industrial safety, better quality and compatibility. However, unlike industrial production line, in construction industry, automation has number of barriers like uncertainty incidents and intellectual judgment to make ability to make solution out of it. Therefore construction industry is still demanding use of construction machine through labor. Due to this matter operational labor in construction industry is aging and fading. To solve these problem, in developed nations like Europe, US or Japan are keep researching for the automation in construction and road pavement, strengthening and some other simple operations have been worked through automation but in civil engineering site, automation research is still low despite of its importance in constructional site. For automating civil engineering operation, effective operational plan have to be set by analyzing ground information acquainted. If skillful worker apply heuristics, trial & error can be reduced with increased safety and the effective work plan can be established. Hence, this research will introduce Intellectual Task Planning System for Intelligent Excavating System's effective work plan and heuristics applied in each steps.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.328-336
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• 2013

This study was conducted to evaluate imported tomato $F_1$ cultivars as breeding materials for the resistance to Tomato yellow leaf curl virus (TYLCV) by molecular markers and bioassay. From marker genotyping and disease evaluation of 40 $F_1$ cultivars, most of the cultivars declared as TYLCV-resistance carried heterozygous marker genotype for the TYLCV resistance genes Ty-1, Ty-3, or Ty-3a, and showed low disease rates. Whereas, 4 of 5 $F_1$ cultivars declared as intermediate resistance showed marker genotype for susceptibility and disease rates ranged 18.1-33.3%. However, the xx cultivars showed inconsistency in marker genotype and disease rate. Characterization of horticultural traits of the $F_1$ cultivars with TYLCV-resistance indicated that large-size fruit cultivars were higher in yield and similar in sugar contents and solid-acid ratio compared to a control cultivar preferred in the domestic market, although hardness remained to be a problem. On the other hand, cherry tomato cultivars showed lower yield and brix, but longer internode compared to a control cultivar, indicating that breeding for TYLCV-resistance using these cultivars will require more efforts and time compared to large-sized.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.8-17
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• 2018

A large urban region in Bangkok, Thailand is often inundated due to shallow water floods along the paved roads that have poor drainage facilities, and that can cause urban flooding. Existing methods, including using sand bags are not effective to prevent flooding in urban areas where the amount of sand is not sufficient. Thus, it is necessary to install artificial flood defense structures. However flooding and overflow defense equipment, which was developed in some advanced nations in Europe and in the USA, is highly expensive and complex construction methods are needed, therefore they are not suitable to be used in Southeast Asia. Thus, it is necessary to develop a flood rapid defense system(FRDS), which is inexpensive and simple to build, but is also highly functional. Thus, this study developed an FRDS that can be applied to Southeast Asia through the careful study of FRDS overviews, an analysis on the development trends in Korea and overseas, and the proposal of development needs and directions of the region. For the system developed, Korean Standards(KS) performance evaluations on leakage ratio deformation tests and impact resistance tests were conducted at the Outdoor Demonstration Test Center(Seosan) in the Korea Conformity Laboratories(KCL) and the system satisfied the standards of KS F 2639(leakage and deformation test) and KS F 2236(impact resistance test). The present study results can not only be applied to urban floods in Southeast Asian nations to cope with flood-related disasters, but also be utilized in flood prone regions and for major facilities in Korea. They can also induce scientific and pro-active responses from major local governments and facility management organizations in relation to urban floods.