• 항공우주기술
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• 제6권1호
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• pp.55-63
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• 2007

과학기술위성 2호는 국내에서 최초로 개발되는 소형위성발사체(KSLV-1)에 의하여 국내 발사장(나로 우주센터)에서 발사될 위성이다. 2002년 개발을 시작하여 엔지니어링모델(EM), 준비행모델(PFM), 비행모델(FM)을 개발 완료하였다. 위성의 기능을 점검하기 위해 종합적인 전기/전자 기능시험과 우주환경시험, 발사환경시험을 수행한다. 본 논문은 성공적으로 수행한 과학기술위성 2호 준비행모델의 우주환경시험과 발사환경시험에 대한 분석과 그 결과를 보고한다.

• 한국환경교육학회지:환경교육
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• 제20권4호
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• pp.166-179
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• 2007

The purpose of this study is to find a concrete plan by examining effect of environmental education program on Environment-friendly Attitudes in sixth grade elementary school and to testify the educational values of environmental education program. The study was carried out by 32 students, which was experimental group and by 32 students, control group, in the sixth grade of Y elementary school located in yangjung, Busan city. Both group was found out the same quality group through the pre-test. Environmental class using environmental education program was applied to experimental group and traditional lecture class was applied to control group. After executing post-test to each group, comparative analysis was conducted by t-test using a SPSS 12.0 program. The result of post-test showed that experimental group taken environmental class using environmental education program was more statistically meaningful than control group taken traditional lecture class in the cognitive, emotional, behavioral area. As a result, in sixth grade elementary school environmental class using a environmental education program was more effective in knowledge-acquirement about the overall environ mental programs, and in fostering Environment-friendly Attitudes and behaviors than traditional lecture class. The teacher must develop efficient environment education program in such side.

• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.877-883
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• 2020

The purpose of the article is to evaluate the factors that affect the degree of environmental accounting information disclosure. Data are collected from 87 industry companies listed on the Vietnamese stock market from 2009 to 2019. I focus on the effect of factors such as the Firm size, Profitability, Leverage, Firm age, and Independent auditors. To explain the causal relationship between factors, I construct the regression model and then test it by using different statistical method approaches, including the pooled OLS, the fixed effects model, and the random effects model. Then I conduct testing of model defects: White Test, Wooldridge Test, Hausman Test, and Wald Test. The Feasible Generalized Least Squares (FGLS) method is used to analyze the image factors that affect environmental accounting information disclosure. The results show that the extent of environmental accounting information disclosure is influenced by factors: firm size, uptime and independent audit. These factors positively affect the level of environmental accounting information disclosure; independent audit has the greatest influence. Based on the research results, the author gives recommendations to improve the disclosure of environmental accounting information for industrial enterprises listed on the Vietnamese stock market, increasing the competitiveness of the public company in terms of global integration.

• 한국물환경학회지
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• 제33권4호
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• pp.481-486
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• 2017

This paper aims to evaluate the characteristics of direct and indirect effluents'toxicity level and difference between two test durations (24 h and 48 h) of test method. The proportion of the indirect effluent samples which exceeded the ecotoxicity permit limitations (TU 1 or TU 2) showed more than 2 times higher than that of direct effluent samples. However, effluent toxicity of Wastewater Treatment Plants (WTPs) indicated less than TU 1 regardless of influent toxicity. From this results, treatment process was thought to have a good efficiency. WTP Salinity was very similar between influent and effluent. This trend could be reconfirmed by the component ratio of ion concentration between them and $Na^+$, $SO_4^{2-}$, $C^-$ lions which have a greater percentage than other ions. In addition, in case of high salinity, toxicity value also showed high level. To judge from above results, indirect effluents which were exempted from application of ecotoxicity standards, may need a new effluent limitations regardless of the treatment efficiency of WTP. According to circumstances, effective countermeasure may need to restrain the discharge of salinity-contained effluents which came from indirect-effluent factories. Test duration comparative study indicated that 48 h results were higher toxicity (exceeding rate of ecotoxicity criteria) than 24 h by the 5 to 5.4 percentage. 24 h test duration seemed to be useful in case of rapid detection, whereas 48 h test method could be applied for reinforcement of ecotoxicity regulatory system.

• 시스템엔지니어링학술지
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• 제16권2호
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• pp.78-86
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• 2020

The environmental tests are one of the key branches of the reliability tests. The purpose of the high/low environmental test of KT-1 Export Version Trainer is not only based on meeting the compliance of the reliability, customer satisfaction, but also for the expansion of its export. Amongst many existing environmental tests, the high and low temperature tests are considered as the two most important tests. The tests are considered and tailored to the high and low temperature methods of MIL-STD-810H. This paper proposes the tailoring processes and the results of High/Low temperature conditions, test procedures, and test profiles for the aircraft. Additionally, this paper is described by considering the view of MIL-STD-810H.

• 한국물환경학회지
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• 제30권6호
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• pp.632-637
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• 2014

Proficiency testing by interlaboratory comparisons is used to determine the performance of individual laboratories. In order to verify the quality of acute toxicity testing with Daphnia magna, National Institute of Environmental Research in South Korea is regularly organizing interlaboratory comparisons to estimate the analytical accuracy of different laboratories. Total 58 laboratories located in South Korea took part in interlaboratory proficiency testing scheme with three proficiency testing samples. TU(Toxic Unit) values of each laboratory were determined and robust z-score was calculated in order to evaluate the proficiency levels. Based on the robust z-score classification, 74% of the participant laboratories showed a satisfactory performance (43 laboratories). The main reason of 'unsatisfactory' performance seemed to be considered that the unsuitable management of test organism incubation system and the lack of experience on the identification of the test organism condition by effect of toxicity.

• 환경영향평가
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• 제6권1호
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• pp.111-119
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• 1997

This study was carried out to suggest the best statistical test which may be used to quantify the change of water quality between two groups. Traditional t-test may not be used in cases where the normality of underlying population distribution is not assured. Three non-parametric tests which are based on the relative order of the measurements, were studied to find out the applicability in water quality data analysis. The sign test is based on the sign of the deviation of the measurement from the median value, and the binomial distribution table is used. The signed rank test utilizes not only the sign but also the magnitude of the deviation. The Wilcoxon rank-sum test which is basically same as Mann-Whitney test, tests the mean difference between two independent samples which may have missing data. Among the three non-parametric tests studied, the singed rank test was found out to be applicable in the quantification of the change of water quality between two samples.

• 한국전산유체공학회지
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• 제13권4호
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• pp.24-32
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• 2008

Environmental test is divided into operation test and storage test. The temperature of storage test is induced temperature which is considered with all sort of the heat source. Induced temperature is the temperature to be adapted to each item and platform and can be induced by computer simulation, laboratory, and real field test. We considered the induced temperature to be associated with solar heat source. In this research. First, we compared the induced temperature which be occurred by one experiment for thin plate in solar test chamber with the other one which be occurred by computer simulation to be SolidWorks 2007 COSMOS FloWorks. After this verification, we showed induced temperature which can be occurred when the test item is stored. Especially, we bring out the induced temperature by applying the ambient temperatures which is presented by MIL-STD-810F and brought out in preceding research.

• 한국환경보건학회지
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• 제33권1호
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• pp.36-42
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• 2007

Diesel PM can be controlled using Diesel Particulate Filter, which can effectively reduce the level of soot emissions to ambient background levels. In the Heavy Duty Diesel area, the Continuously Regeneration trap has been widely applied in the retrofit market. As the Special act for the improvement of air quality in the capital area, the retrofit program for DPF to used diesel vehicle has progressed favorably and there are currently over 1,000 of these DPF in use in retrofit applications in korea. These DPF comprise a specially formulated Diesel Oxidation Catalyst upstream of a DPF. The $NO_2$ generated by the DOC is used to combust the carbon collected in the DPF at low temperature. To certificate DPF device that is suitable to domestic circumstances, it is necessary to evaluate exactly the DPF devices according to the regulation of DPF certificate test procedure for retrofit(ministry of environment(MOE) announcement NO. 2005-16). To do so the understand of that regulation like the standard of PM reduction rate is needed. In this study the test procedure including test cycle and BPT test condition was examined and also the test result for specific DPF was analyzed. In every test like field test, PM reduction efficiency test and seoul-10 mode test, no defect could be showed.

• 한국가정과교육학회지
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• 제10권1호
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• pp.1-16
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• 1998

The purpose of this study was to investigate the middle school and high school student's environmental consciousness and clothing behavior for environmental protection in their home, and to present the basic educational material for the reasonable clothing behavior which could help the environmental problems. This study was done by self-administered questionaires to the 439 middle school and high school students, and done from March to April in 1997. Frequencies, percentages, mean, and standard deviation were calculated. $\chi$$^2$-test, t-test, and F-test were done for group differences, and Duncan's multiple range test was followed. The results of this study were as follows ; 1. Environmental consciousness was higher at the middle school students, at good graded students, and at the good news receivers who watch or listen to the mass media frequently. And also environmental consciousness was higher at the students who separate and dispose waste practically and at those who realize the need of environmental education. 2. Those who purchase clothes reasonably in their home, practising the clothing behavior for environmental protection, were the middle school students, and the students sho watch or listen news frequently through the mass media. And those who manage clothes well in their home were the middle school students, metropolitan area residents, good news receivers, and residents in apartments. Those who separate and dispose waste well, those who have experienced much environmental education, those who know better the environmental protection marks which are attatched to the low pollution products and those who realize the need of environmental education seriously, were almost the same students who buy and manage clothes reasonably in their home, practising the clothing behavior for the environmental protection. And those who feel much more environmental education seriously were those who reuse clothes practically in their home. 3. As the students had the higher environmental consciousness level, the better they practised the clothing behavior for environmental protection in their home. The major sources of the students'knowledge and information about environment were from the mass medea, and then from school teachers.