• Analytical Science and Technology
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• v.25 no.3
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• pp.178-189
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• 2012

As phthalates classified as toxic to reproduction category 2 and endocrine disrupting chemicals were more strictly regulated as Substances of Very High Concern (SVHC) for authorization in under EU REACH and considered as priority substances in RoHS II, standardization of phthalate testing method is now being proposed in IEC 62321 of IEC TC 111 and the 2nd revision of KS M 1991 is also finished. In order to assist standardization activities related to phthalating testing, solvent extraction part of existing national standards were compared and verified. Recovery of DEHP (diethylhexyl phthalate) from PVC (polyvinyl chloride) by Soxhlet extraction increased in the order of methanol, toluene, dichloromethane and hexane from 46.9% to 95.3% as measured by GC-MS. Optimum extraction time was verified to be 6 hours using hexane. Recovery of DBP (dibutyl phthalate), BBP (butylbenzyl phthalate), and DEHP from different matrixes such as PVC, nitro cellulose, ABS (acrylonitrile butadiene styrene). and EPDM(ethylene propylene diene monomer) rubber were evaluated to be more than 90% up to 99%. The detection limits of phthalates in solvent extraction followed by GC-MS analysis were 0.08~0.3 ${\mu}g/mL$ in solution and 8~30 mg/Kg in polymeric samples. GC-MS analyses of phthalates were carried out using different solvent extraction based on the EN 14372, ASTM D 7083, Japanese test method (MHLW 0906-4) and KS M 1991, proving that equivalent recoveries ranging from 98%~99% were obtained. DBP and DEHP were detected in three consumer products such as a child toy, a power cable and manicure with the amount of 22~1,910 mg/kg.

• Korean Security Journal
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• no.20
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• pp.249-270
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• 2009

There have been great demands for various private searches and collecting information activities. but in korea it is still banned to supply private investigation service and to use the term 'private investigation'. So establishment of desirable model for private investigation service system is essential factor in strategic approaching for privatization of policing. In most developed countries private investigation service system is generally permitted and various methods to solve the side effects of that are considered. It is necessary to revise more the Security Business Law to introduce private investigation service system so that the dispute on determining how to do and what to do. It looks like that police agrees with the introduction of the private investigation service system because this could be an option when it comes to the job that its members can take after retirement and because this system helpful their own work. Actually Korea government have tried to prepare the law enactment of the private investigation service system since 1999 but have been failed. This study focuses on implementing the suitable system for private investigation service in Korea, which includes the consideration of the logical validity of the introduction by comparing with other foreign private investigation service system. We should make research and effort to cope with such as a partial amendment about the problem and the side effect that can be happened in a beginning stage of system trial.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.49-62
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• 2006

The republic of korea has put a great emphasis on the role of the road as widening a social infra-structural facility. Thus, vast amount of money has been invested on the road establishment. As a result, there has been fruitful outcomes in establishing the road system of the nation especially for the flat road with ease. However, in order to have more systematic and sustainable road system, we should turn our attention to more painful and high-cost regions such as mountainous districts and those are to be developed effectively. The configuration of the road is an important factor to be considered in making a decision for the road planning. Nevertheless, current road planning criterion has no such clarified and objective judging standard for figuring the configuration of the road out and, as a result, speed planning can be decided incorrectly. our research has acknowledged the necessity of estimating the configuration of the road and aimed to make it organized and sorted according to the height, slope, and the vehicle's speed. The results are as follows. First, our research made use of GIS data and classified the road into 9 different areas according to the height and the slope. Also, road classification being matched to the data of vehicle's speed, it has been shown that those characteristics of different areas have made an influence on vehicle's speed. Secondly, based on the results of the similarity between geographical classification and, vehicle's speed of sorted groups according to the height and the slope, conclusively we have classified as flat, rolling region and mountain. Since our research has made use of vehicle's speed for National Highway, it is not applicable to different functional highways. However, for the highway to be established hereafter, it can be a standard for reflection geographical characteristics.

• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.95-108
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• 2005

The purpose of this study is to develop the ITS evaluation model using the Probabilistic Risk Analysis (PRA) methodology and to demonstrate the goodness-of-fit of the large ITS projects through the comparative analysis between DEA and PRA model. The results of this study are summarized below. First, the evaluation mode] using PRA with Monte-Carlo Simulation(MCS) and Latin-Hypercube Sampling(LHS) is developed and applied to one of ITS projects initiated by local government. The risk factors are categorized with cost, benefit and social-economic factors. Then, PDF(Probability Density Function) parameters of these factors are estimated. The log-normal distribution, beta distribution and triangular distribution are well fitted with the market and delivered price. The triangular and uniform distributions are valid in benefit data from the simulation analysis based on the several deployment scenarios. Second, the decision making rules for the risk analysis of projects for cost and economic feasibility study are suggested. The developed PRA model is applied for the Daejeon metropolitan ITS model deployment project to validate the model. The results of cost analysis shows that Deterministic Project Cost(DPC), Deterministic Total Project Cost(DTPC) is the biased percentile values of CDF produced by PRA model and this project need Contingency Budget(CB) because these values are turned out to be less than Target Value(TV;85% value), Also, this project has high risk of DTPC and DPC because the coefficient of variation(C.V) of DTPC and DPC are 4 and 15 which are less than that of DTPC(19-28) and DPC(22-107) in construction and transportation projects. The results of economic analysis shows that total system and subsystem of this project is in type II, which means the project is economically feasible with high risk. Third, the goodness-of-fit of PRA model is verified by comparing the differences of the results between PRA and DEA model. The difference of evaluation indices is up to 68% in maximum. Because of this, the deployment priority of ITS subsystems are changed in each mode1. In results. ITS evaluation model using PRA considering the project risk with the probability distribution is superior to DEA. It makes proper decision making and the risk factors estimated by PRA model can be controlled by risk management program suggested in this paper. Further research not only to build the database of deployment data but also to develop the methodologies estimating the ITS effects with PRA model is needed to broaden the usage of PRA model for the evaluation of ITS projects.

• Journal of Chest Surgery
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• v.40 no.3 s.272
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• pp.159-167
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• 2007

Background: Vocabularies originating from Chinese characters constitute an important common factor in the medical terminologies used 3 eastern Asian countries; Korea, China and Japan. This study was performed to comparatively analyze the medical terminologies of these 3 countries in the field of cardiopulmonary bypass (CPB) and; thereby, facilitate further understanding among the 3 medical societies. Material and Method: A total of 129 English terms (core 85 and related 44) in the field of CPB were selected and translated into each country's official terminology, with help from Seoul National University Hospital (Korea), Tokyo Michi Memorial Hospital(Japan), and Yanbian Welfare Hospital and Harbin Children Hospital (China). Dictionaries and CPB textbooks were also cited. In addition to the official terminology used in each country, the frequency of use of English terms in a clinical setting was also analyzed. Result and Conclusion: Among the 129 terms, 28 (21.7%) were identical between the 3 countries, as based on the Chinese characters. 86 terms were identical between only two countries, mostly between Korea and Japan. As a result, the identity rate in CPB terminology between Korea and Japan was 86.8%; whereas, between Korea and China and between Japan and China the rates were both 24.8%. The frequency of use of English terms in clinical practices was much higher in Korea and Japan than in China. Despite some inherent limitations involved in the analysis, this study can be a meaningful foundation in facilitating mutual understanding between the medical societies of these 3 eastern Asian countries.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.2
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• pp.132-140
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• 2005

This study was conducted to develop regional site index equations for main tree species in Gangwon, Gyunggi-Chungcheong, Gyungsang, and Jeolla area of Korea, using environmental and soil factors obtained from a digital forest site map. Using the large data set obtained from the digital forest map, a total of 28 environmental and soil factors were regressed on site index by tree species for developing the best site index equations for each of the regions. The selected main tree species were Larix 1eptolepis, Pinus koraiensis, Pinus densiflora, Pinus thunbergii, and Quercus acutissima. Finally, four to five environmental and soil factors by species were chosen as independent variables in defining the best regional site index equations with the highest coefficients of determination $(R^2)$. For those site index equations, three evaluation statistics such as mean difference, standard deviation of difference and standard error of difference were applied to the data sets independently collected from fields within the region. According to the evaluation statistics, it was found that the regional site index equations by species developed in this study conformed well to the independent data set, having relatively low bias and variation. It was concluded that the regional site index equations by species had sufficient capability for the estimation of site productivity.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.95-95
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• 2018

강재의 방식법 중 도장은 부식을 억제하는데 효과적이고 편리한 방법으로 선박 및 해양 강 구조물의 방식법으로 사용되고 있다. 한편, 강 구조물의 효율적인 유지관리를 위해서는 방식 도장의 도막 열화도를 평가하고 잔존 수명을 예측하여 최적 시기에 보수도장 혹은 재도장하는 것이 필요하다. 일반적으로 선박 및 해양구조물에 적용되는 도막의 방식 성능 평가 방법으로 해수 침지 시험, 염수 분무 시험, 옥외 폭로 시험 등이 있다. 그러나 이러한 시험들은 그 시험 방법에 따라서 정량적인 평가에 한계가 있음은 물론 장기간 소요되는 등 곤란한 문제점이 있다. 그러므로 선박 및 해양구조물을 비롯하여 교량, 각종 강 구조물의 도장 방식에 사용되는 방식용 도료의 성능을 단기간에 적절하게 평가할 수 있는 가속시험법이 제시되며 연구-사용되고 있다. 그 중 도막 방식 성능을 보다 효율적, 비파괴적, 정량적으로 평가할 수 있는 임피던스 분광법(EIS)과 같은 전기화학적 방법은 상대적으로 시험 기간을 크게 단축시킬 수 있고, 대상 방식 도장의 미세한 성능 차이도 분별 가능하다는 장점이 있다[1]. 따라서 본 연구에서는 선박 및 해양구조물 등 가혹한 부식환경에서 강력한 내구성을 가질 수 있도록 다양한 종류의 표면처리 도장 시편을 제작하여 자외선 조사-염수분무-침지환경 등의 열악한 환경조건 하에서 부식-열화 촉진 시험을 실시하였다. 그리고 그 촉진 열화 과정에서 도막의 외관 상태를 관찰 분석함은 물론 전기화학적 임피던스 분광법을 병행 측정하며 그 표면막의 부식 및 도막 열화도를 비교-종합 평가하였다.본 연구에 사용된 시편은 Al 및 Zn 도금 강판에 에폭시, 에폭시-실리콘 우레탄, 에폭시-우레탄 도장 시편으로 Scribe, No Scribe 및 비교재 Al 및 Zn 도금 시편으로 분류하여 각각 실험을 진행하였다. 즉, 도막 열화 시험은 복합 노화 시험법으로 UV 조사 36 시간(ASTM G53), 염수분무 32 시간(ISO 7253), 수분 응축 10 시간을 1 Cycle로 100 Cycle(7800 시간) 동안 실험을 진행하였다. 이때 도막 열화도 평가는 전기화학적 임피던스 분광법을 이용하여 각 실험 조건별로 주파수에 따른 임피던스(Z) 값을 평가하였다. 즉, 상온 $25^{\circ}C$의 3.5% NaCl 100 ml 수용액에 작동 전극(Working Electrode)과 구리 도선을 통해 연결하였고, 노출 면적은 $1cm^2$로 일정하게 유지 하였으며, 상대 전극(Counter Electrode)은 탄소봉, 기준 전극(Reference Electrode)으로 포화카로멜전극(Saturated Calomel Electrode)을 사용하여 측정하였다. No Scribe 시편의 경우에는 Al 기판 에폭시-실리콘 우레탄 도장 시편이 우수한 도막 저항성을 나타내었으며, 에폭시-우레탄 도장시편은 23사이클 이후의 저항값이 가장 낮게 나타났다. Zn 기판의 경우는 에폭시, 에폭시-실리콘 우레탄, 에폭시-우레탄 도장 시편 모두 저항 값이 유사하였으며, Al 및 Zn 도금 시편은 도장 처리된 시편에 비해 훨씬 낮은 저항 값을 보였다. 또한 Scribe 시편의 경우에는 Al 기판 에폭시-실리콘 우레탄 도장 시편에서 높은 초기 저항 값을 보였으며, 23 사이클 후의 저항 값은 세 종류의 도막에서 약 1~0.1 Gohm 으로 나타났다. 그리고 Zn 기판 에폭시-실리콘 우레탄 도장 시편에서 가장 낮은 도막 저항 값이 나타났다. 이상의 실험을 통해서 본 연구 내용은 실내촉진시험으로 선박 및 해양 강 구조물에 사용되는 다양한 종류의 도막의 열화도를 평가하는 기초 설계 지침으로 응용될 수 있을 것으로 사료된다. 한편, 도막은 노출 환경에 따라 방식 성능이 다르므로 실제 도막의 사용환경을 고려하여 도장 사양별 적용 부위에 따른 적정 가속 실험 방법을 선정할 필요가 있다고 사료된다.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.776-785
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• 2008

Maternal stress was one of the common symptoms that pregnant women could have experienced during pregnant period. The purpose of this study was to investigate the relation of maternal stress with maternal nutrients intake and pregnancy outcome. Subjects were 248 pregnant women and were recruited at two hospitals in Seoul area. Individual stress levels were divided by the stress scores (total 41 scores), as low stressed group (< 12) and high stressed group (${\geqq}12$). The social characteristics, nutrient intake, anthropometric measurements and pregnancy outcome were compared between low stressed group (LSG) and high stressed group (HSG) to recognize risk factor of maternal stress. We found that subjects experience stress by various factors which were concern about newborn (40.4%), concern about health (28.8%), economic difficulties (13.2%), depress (10.1%), family relationship (2.9%), concern of house work (2.5%), human relationship (2%). In HSG, unemployed rate (p < 0.05) and pre-pregnancy BMI (p < 0.05) were higher than in LSG. Family size in HSG was larger than that in LSG (p < 0.01). Doing regular exercise with the light activity level was significantly higher in LSG (p < 0.05). The nutrient intake in LSG was slightly higher than that in HSG, but not statistically significant. Pregnancy outcome was not significantly affected by the maternal stress. In conclusion, the risk of maternal stress may be related with a life style during pregnancy. Therefore, life style for maternal stress control, such as weight control and regular exercise is recommended to prevent maternal stress.

• Journal of The Korean Society of Grassland and Forage Science
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• v.3 no.2
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• pp.67-76
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• 1983

This experiment was carried out to investigate the effects of the different nitrogen rates and cutting heights on the dead stubble after cutting, and the carbohydrate reserved in stubble of sorghum-sudangrass hybrid (Sorghum bicolor (L.) Moench) Pioneer 988. The experiment was undertaken in the Experimental Livestock Farm of Agriculture Coll., Seoul Nat'l Univ. In Suweon, 1981 and 1982. The results obtained are summarized as follows: 1. The dead stubble after cutting was found to be great with high rate of nitrogen fertilizer and low cutting height. It was also learned that the rainfall during forage cutting period made the dead stubble increased. 2. A significant higher (p<0.05) carbohydrate reserves in the stubble was observed in the high stubble height at the first cutting time and 6th through 7th day after the first cutting. The results indicate that the high stubble height reserves more carbohydrate for the early regrwoth stage after the first cutting when comparing with the low stubble. 3. The content of carbohydrate reserves was influenced by climete. Drought is caused to high content of carbohydrate, whereas, rain is caused to low content of that. The critical soluble carbohydrate content causing the death of stubble supposed to be 3 to 6% at least. 4. It is suggest that carbohydrate reserves in plant do not play a distinctive role for the regrowth in a summer annual forage like sorghum-sudangrass hybrid, but it might be rather influenced by the other factors, for example, environmental conditions at harvest and new bud.