• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1088-1093
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• 2010

The Smart bi-directional pile load test with variable end plate overcomes the shortcoming of the Osterberg cell test. It is possible that the ultimate bearing capacity of piles can be known by using two different end plates. The first step is to measure end bearing capacity with smaller end plate and the second step is similar to the conventional O-cell test. In this study, model test was performed to evaluate the smart bi-directional pile load test in sand. Vertical displacement of the model pile were messured at the axial loading condition.

• 한국신뢰성학회지:신뢰성응용연구
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• 제6권1호
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• pp.27-36
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• 2006

It is increasingly important to ensure that a given vibration test specification of a particular machinery component is appropriately established by considering its real environmental conditions. Vibration test standards for electrical components are well documented, for example in an IEC 60068 series, while standards for machinery components are rarely found except a few military standards. Thus many vibration tests are performed based on the military standards. However, a test based on these military standards often results in over-testing, and under-testing in some cases due to the different environmental conditions. Also, these standards require an appropriate tailoring that may not be easily accomplished. In this paper, various international and military standards are compared and investigated to obtain test specifications relevant for machinery components. Also appropriate tailoring methods are demonstrated through a case study.

• 한국지반환경공학회 논문집
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• 제5권2호
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• pp.33-39
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• 2004

대부분의 말뚝기초는 두부 고정상태이지만, 수평재하시험은 일반적으로 두부 자유상태에서 시행되었다. 이번 논문은 두가지 경우(두부고정, 두부자유)에 대한 말뚝깊이별 수평변위와 이론 방정식과 현장수평재하시험을 비교해가며 대구경현장타설말뚝의 수평거동을 분석한 말뚝현장수평재하시험을 수행하였다.

• 한국환경보건학회지
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• 제45권3호
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• pp.285-294
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• 2019

Objectives: For suitable risk management of the domestic aquatic environment, it is necessary to conduct toxicity tests using species native to Korea. In the present study, we performed toxicity ring tests using endemic freshwater arthropoda Neocaridina denticulata and evaluated its validity and reproducibility as an international standard test species. Methods: To evaluate the sensitivity levels of N. denticulata to hazardous chemicals, toxicity values for several chemicals were compared with other standard test species. Intra- and inter-laboratory acute toxicity tests were performed both within a single laboratory and among four laboratories respectively using 3,4-Dichloroaniline, which is generally used as a reference test substance in fish toxicity tests. In addition, intra- and inter-laboratory coefficient of variations (CVs) were calculated to evaluate reproducibility based on the estimated toxicity values. Results: The sensitivity of N. denticulata to several chemicals was found to be similar with D. manga, indicating that the species is valid as a test species. The CVs of the intra- and inter-laboratory tests were 22.946% with four qualified runs and 8.828% among the four laboratories, respectively. Conclusions: N. denticulata serves in an important role in the food chain of Korean aquatic ecosystems and also inhabits several other Asian countries. Since the validity and reproducibility of the species were confirmed as a toxicity test species in this study, further efforts are needed to establish N. denticulata as the international standard test species for the appropriate risk assessment of aquatic ecosystems at home and abroad.

• 한국물환경학회지
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• 제21권6호
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• pp.651-658
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• 2005

The Non-parametric Analysis is powerful in data test especially for the non- normality water quality data. The data at three monitoring stations of the Tam-Jin River were evaluated for their normality using Skewness, Q-Q plot and Shapiro-Willks tests. Various constituent of water quality data including temperature, pH, DO, SS, BOD, COD, TN and TP in the period of January 1994 to December 2004 were used as dataset. Shapiro-Willks normality test was carried out for a test 5% significance level. Most water quality data except DO at monitoring stations 1 and 2 showed that data does not normally distributed. It is indicating that non-parametric method must be used for a water quality data. Therefore, a homogeneity was conducted by Mann-Whitney U test (p<0.05). Two stations were paired in three pairs of such stations. Differences between stations 1, 2 and stations 1, 3 for pH, BOD, COD, TN and TP were meaningful, but Tam-Jin 2 and 3 stations did not meaningful. In addition, a narrow gap of the water quality ranges is not a difference. Categories in which all three pairs of stations (1 and 2, 2 and 3, 1 and 3) in the Tam-Jin River showed difference in water quality were analyzed on TN and TP. The results of in this research suggest a right analysis in the homogeneity test of water quality data and a reasonable management of pollutant sources.

• 한국환경교육학회지:환경교육
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• 제20권1호
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• pp.90-105
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• 2007

The purpose of this study is to find the influence of environmental issue analysis instruction on the environmental decision making ability for grade 5 elementary school students. The study was done through pre and post testing control group structure. The object of this study is grade 5 of I elementary school students which were divided into 35 student test group and 54 student control group. Through studying references, the selection standard of appropriate environment issue and the environmental issue analysis instructing objective. Conducted the environment issue instructing based on the selected environment issue and instructing objective. The classes were held in total of 6 sessions in the chapters related to class objective and class content within the curriculum. The pre and post testing was done using environment decision making ability test sheet which was reconstructed by myself and the results were analyzed by t-test. As a result of comparing pre and post testing the students in test group showed significant results in the processes of problem recognition, evaluation of alternatives, behave planing (p<.001). As a result of comparing the differences of environment decision making ability of pre and post test of test group and control group, it showed significant results in the process of evaluation of alternatives(p<.00l). The environment issue analysis class has positive influence on the environment decision making abilities of the students but since the outcome of environment decision making ability is lower, there is a need for long term environment education plan and further studies to find whether the environment issues within the textbook is appropriate in the elementary student level, useful school aspect and the influence of environment issue analysis class on the change of values for individuals.

• 대한가정학회지
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• 제33권1호
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• pp.45-60
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• 1995

The purpose of this study is to investigate some influencing factors related to the perception and the management behavior on the environmental pollution of the housewives in the metropolis. small city and Kun. This study is also to provide some knowledge and information on the environmental preservation. 2300 questionaires were distributed to the housewives from the end of April to the end of May in 1994. The 1850 quentionaires were obtained and the 1490 data were analyzed by frequency, percentage, mean, t-test, F-test, Duncan's prohoc test, stepwise multiple regression, path analysis and pearson's correlation. The most hypotheses of this study were accepted. Based on the findings of this study, the degree of concerns on the environmental provlems, the enviromental education, the einvironmental articles and the paticipation of the environmental events were the most important factors on the knowledge of the environmental preservation and the perception of the environmental pollution. And these factors were exerted important effects on the management behavior on the environmental preservation.

• 한국환경과학회지
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• 제17권8호
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• pp.827-831
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• 2008

We investigated the education process of an environmental experiment in middle and high school. The major objective was that students understand about biological toxicity of endocrine disruptor. We used bisphenol A in environmental experiment to educate them about the effects of endocrine disruptor. The test animal was zebrafish (Danio rerio, wild type) which is very easy to use in the school experiment class. We educated the high school students (n=25) in Suwon through this teaching program. Finally we analyzed the effect of research education between two groups, education students (test) and non-education students (control). This experiment showed there were some positive effects on environmental reorganization of students. They understood the affect of endocrine disruptors in fish and man. Specifically, understanding the importance of preservation of ecosystem increased in the test-education group.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.62-70
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• 2007

Most design temperature of environmental test in korea is based on the standard of Department of Defense. There are few studies to establish temperature standard. Besides the representative environmental test guide 'MIL-STD-810F' encourage to tailor to generate the most relevant test data possible and to test to make a match of test environment with operational environment. Under these circumstances, it is irrational to comply with baseless daily cycle. Thus the study about design method of test temperature is essential. So, the daily cycles to be appropriate to the Korean peninsula was presented in this study. And this research shows how to derive two main element, frequency-of-occurrence and daily maximum (minimum) temperature in daily cycles, in case we can not find the daily cycle.

• 한국환경교육학회지:환경교육
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• 제22권4호
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• pp.14-25
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• 2009

The purpose of this study was to investigate the effects of the forest experience on elementary students' environmental sensitivity and cognition ability. The forest experience was applied to the experimental group and the control group was taught by the traditional teaching method focused on teachers' lecture for 8 lessons. The pre-test, the 1st, and 2nd post-test for environmental sensitivity were applied to both groups to analyze the effects of the forest experience. After then the results were analyzed by One-way ANOVA and ANCOVA. And the narration test for cognition ability on learning a environmental context was applied to only the experimental group and the results were analyzed. As a result, the students' environmental sensitivity was not significantly different(p<.05) between experimental and control groups in terms of the pre-test score. However, the 1st and 2nd post-test scores of experimental group were significantly higher than those of the control group in term of the level of environmental sensitivity(F=9.28, p<.01, F=10.95, p<.01). The results of the forest experience in the aspect of cognition ability, 'the sound of nature(61%)', 'the smiling forest path which blooming out(57%)', and 'one's own places(52%) were high but 'the kinds and characteristics of the roots(30%)' was low. In conclusion, the forest experience made a positive effect on the students' environmental sensitivity and cognition ability through the direct observation, data collection, and analysis on the nearby natural environment.