• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.5
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• pp.130-135
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• 2013

Anti-icing system can reduce traffic accidents and congestion by quickly removing the frozen road surface area. there is no decision criteria for determining application of the Anti-icing system in Korea. In this study, we proposed the decision criteria for determining application of the anti-icing system based on weather and road conditions, i.e., geometric and topographic conditions. Regional climate survey, Solar Radiation analysis, and dynamic vehicle simulation considered road geometry was conducted to standardize the installation method of anti-icing system. Also, we have developed a software that can be determined an installation of anti-icing system.

• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.24-30
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• 2002

Ginseng (Panax ginseng C. A. Meyer) has been cultivated on raised beds with shading condition for 4 to 6 years because of its physiological characteristics. This shading condition maintains relatively stable soil environments protecting from rainfall and direct sunlight. Therefore, pesticides in ginseng growing soil are exposed to far different environment from the general cropping field. To study the behavior of pesticides under this condition, the effect of covering on the persistency of Procymidone in ginseng cultivating soil was investigated by using several shade materials. The most important factor affecting Procymidone persistency in soil under covering was water leakage rates of shade materials.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.54-56
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• 2010

This study was performed to develop anti-obesity Phellineus linteus powder for application as food additives. P. linteus powders which contained anti-obesity lipase inhibitor were prepared by freeze drying and spray drying. Effects of various additives on the quality of their powders were investigated. 10% over addition of dextrin and gum-arabia was good in the rheological properties of their powders and optimal spray temperature was near $130^{\circ}C$. When their powders were sealed and storaged at room temperature for 6 months, its characteristics were not changed. Especially, changes of its colors was repressed by addition of 0.3 M oxalic acid, citric acid and ascorbic acid than those by non-treatment.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.24-33
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• 2011

Wingstem, Verbesina alternifolia of North America origin, was introduced in 1981 into the Korea terrestrial ecosystem. It scattered in a number of places with limited population size in most cases. Its population has spread into the forest at the Chiaksan National Park and occupied the natural vegetation. Distributions of wingstem were the most popular along the 12 road sites, especially in Route 453, Seohwa-myeon, Inje-gun, Gangwon-do and in Route 31, Yeongyang-gun, Gyeongsangbuk-do with 60% coverage of wingstem. It was also distributed in the 5 forest sites and 5 riversides. Despite of its attractive yellow flower, it is recommended to limit cultivation in the nature reserve or other ecosystem of conservation value.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.284-290
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• 2008

In order to elucidate growth characteristics, physiological responses and leaf color changes of leaf-variegated Arundinaria munsuensis and Carex ciliato-marginata for variegata, These experiments were performed under four different light ragimes control(full sun), 40%, 70% and 85%. Plant height and leaf area became promoted as shading level increases in leaf-variegated Arundinaria munsuensis. Photosynthetic effect was the highest in 85% shading of the full sun. Thus, this plant could be growing in the deep shade condition. Plant growth and the leaf color changes were most obviously shown in the 40% shading level. In the Carex ciliatomarginata for. variegata growth status was the best and green or strong greenish yellow leaf color turned out to be much clearer in the 40% shading treatment. And photosynthetic activity was enhanced as the light intensity decreases.

• Korean Journal of Breeding Science
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• v.42 no.4
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• pp.381-389
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• 2010

This study was carried out to develop the breeding and/or cultivation materials by investigating characteristics of natural habitats of Allium monanthum in South Korea. Natural habitats of sunny, half-shady, and shady conditions were 13 (10.7%), 66 (54.6%), and 42 (34.7%), respectively. Natural habitats were located around upland (45.4%), around Buddhist temple area (28.1%), on mountain area (18.2%), along roadside (2.5%), and along riverside (5.8%), respectively. Natural habitats ranged widely in all areas of Korea by $33^{\circ}N{\sim}38^{\circ}N$ and $126^{\circ}E{\sim}129^{\circ}E$. In Chungbuk and Gyeongbuk natural habitats were more than in Jeonbuk and Jeonnam. Distribute pattern were formed densely. Sprout stage was from September till March of next year. Grew from March to April, and there was no plant formed flower stalk in natural habitats.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.35-47
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• 2023

Various single probability distributions have been used to represent time headway distributions. However, it has often been difficult to explain the time headway distribution as a single probability distribution on site. This study used the EM algorithm, which is one of the maximum likelihood estimations, for the parameters of combined mixture distributions with a certain relationship between two normal distributions for the time headway of vehicles. The time headway distribution of vehicle arrival is difficult to represent well with previously known single probability distributions. But as a result of this analysis, it can be represented by estimating the parameters of the mixture probability distribution using the EM algorithm. The result of a goodness-of-fit test was statistically significant at a significance level of 1%, which proves the reliability of parameter estimation of the mixture probability distribution using the EM algorithm.

• Economic Analysis
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• v.25 no.3
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• pp.30-69
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• 2019

This paper analyzes the effects of trade on demand for labor of trading firms in Korea. We apply system GMM methodology to estimate the effects of imports and exports on employment of Korean manufacturing firms using firm-level data from the Survey of Business Activities of Statistics Korea between 2006 and 2014. According to our estimated results, for firms with high-productivity, exports have a positive and significant effect on the labor demand, while other firms do not show any such significant effects. Furthermore, our results show that offshoring mitigates the positive effects of exports on employment, since tasks within the firms can be relocated abroad. On the other hand, an increase in imports reduces demand for labor because labor is replaced with low-priced imported inputs. Also, when firms partake in global outsourcing, the negative effects of imports are mitigated as those firms expand their production by enhancing their efficiency in the process of offshoring. Therefore, our results suggest that it is important to consider heterogeneous firm productivity as well as offshoring in analyzing the effect of trade on labor demand of firms.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.1
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• pp.21-33
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• 2013

The purpose of this study is to find applicabilities of human bioclimatic maps, using human thermal sensation(comfort) in summer, with microclimatic in situ data and computer simulation results at the study site of downtown Daegu. This includes the central business district(CBD) area and two urban parks, the Debt Redemption Movement Memorial Park and the 2.28 Park, for urban and landscape planning and design. Climatic data and urban setting information for the analysis of human thermal sensation were obtained from in situ measurement and the geographic information system data. As a result, the CBD had higher air temperature than the parks when the wind speed was low. Relative humidities were opposite to the air temperature. Especially, same directional streets with local wind direction had lower air temperature than streets perpendicular to the wind direction. The most important climatic variable of human thermal sensation in summer was direct beam solar radiation. Also, creating shadow areas would be the most relevant method for modifying hot thermal environments in urban areas. The most effective method of creating shadow patterns was making a tree shadow over a pergola, and the second best one was making a tree shadow on the front of north directional building walls. Moreover, how to plant trees for creating shadow patterns was important as well as what kind of trees should be planted. The results of human thermal sensation were warm to very hot at sunny areas and neutral to warm at shaded ones. At the sunny areas, wide, squared shape areas had a little bit higher thermal sensation than those of narrow streets. The albedo change of building walls 0.15 and ground surface 0.1 could change 1/6 of a sensation level at the shaded areas and 1/3 at the sunny ones. These microclimatic approaches will be useful to find appropriate methods for modifying thermal environments in urban areas.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.169-178
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• 2008

Level of Service (LOS) is one of ways to evaluate operational conditions. It is very important factor in evaluation especially for the facility of highways. However, some studies proved that ${\upsilon}/c$ ratio and accident rate is appeared like a second function which has a U-form. It means there is a gap between LOS and safety of highway facilities. Therefore, this study presents a method for evaluation of a signalized intersection which is considered both smooth traffic operation (delay) and traffic safety (accident). Firstly, as a result of our research, accident rates and EPDO are decreased when it has a big delay. In that reason, it is necessary to make a new Level of Service included traffic safety. Secondly, this study has developed a negative binominal regression model which is based on the relation between accident patterns and stream. Thirdly, standards of LOS are presented which is originated from calculation between annual delay costs and annual accident cost at each intersection. Lastly, worksheet form is presented as an expression to an estimation step of a signalized intersection with traffic accident prediction model and new LOS.