• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.4
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• pp.299-305
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• 2015

A statistical annoyance model to railway noise at platform was proposed by jury evaluation test performed in hearing laboratory. ITX-Saemaeul and Mugunghwa were chosen as the noise sources of the test, and announcement sound was included to simulate real situation. Logistic regression analysis produced %HA_LAB curve. Hosmer-Lemeshow test and classification accuracy test were used to verify the model's statistical significance. It was shown that the model which was generated from relatively small number of samples is statistically significant.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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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.

• Journal of Korean Home Economics Education Association
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• v.10 no.1
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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.

• Hwankyungkyoyuk
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• v.5 no.1
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• pp.71-88
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• 1993

This study was conducted to develop and effective strategy for environmental education. At first, the environmental education strategy through personalization of environment was proposed. Then students in a middle school participated the program according to the strategy and its. effect was investigated. The strategy was designed in basis of the role of the limbic system in brain and involved field-oriented experience such as viewing the non-personal environment as the personal environment. Gokneung stream was selected as the site to conduct this environmental education. Students investigated water quality by senses and biological method. The same content was taught for the classroom group and simple outdoor group selected for the comparison by traditional instructional method. The pre- and post-test by the instrument to test environmental attitude, qualitative questionnaire, cognitive test, the pre- and post-interview were conducted to investigate the effect the program. The achievement of the classroom group(personalization group). But the change of the attitude toward environment of personalization group between pre- and post-test was significantly higher than the classroom group. In qualitative questionnaire and pre- and post-interviews, attitude toward environment differed between two group. The behavioral change to discover and to solve environmental problems was demonstrated in case the personalization group, but was unclear in the classroom group. These results indicated the environmental education strategy through personalization of environment was an effective strategy to change the awareness, attitude and behavior toward the environment compared with a traditional teaching strategy.

• Hwankyungkyoyuk
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• v.21 no.2
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• pp.11-24
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• 2008

This research verifies the effect on environmental attitude and knowledge accomplishment by t-test as producing and running programs regarding global warming which is raised as a representative environmental issue subject to 6th grade-elementary students. For this, environmental education programs about global warming for elementary students are developed and applied 15 times by reconstituting classes based on the contents regarding global warming from the text books revised as of 7th course of study. The result is as below. First, some part of contents from social study and science of 6th grade elementary curriculum of 7th course of study was able to be reconstituted to 15 education programs. Secondly, the programs about global warming improved students' environmental attitude Application of the programs about global warming showed significant difference(p<.05) on building environmental attitude as it proved those are effective on both area of recognition level and practice level. The method used on the test had .866's Cronbach alpha modulus value therefore, it obtained reliability. Thirdly, the programs regarding global warming improved students' knowledge accomplishment. As a result of test for knowledge accomplishment which was executed with same method for attitude test, the application of the programs about global warming showed significant difference(p<.05) on improving students' knowledge accomplishment on the global warming therefore, it resulted that the application of the program is effective on knowledge acquirement.

• Elastomers and Composites
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• v.53 no.4
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• pp.220-225
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• 2018

Resilient pads play a major role in reducing the impact of loads on a rail in a rail-fastening system, which is essentially used for a concrete track. Although a compression set test is commonly used to measure the durability of a resilient pad, the static spring constant is often observed to be different from the fatigue test. In this study, a modified compression set test method was proposed to monitor the variations in the compression set and static spring constant of a resilient pad with respect to temperature and time. In addition, the life of the resilient pad was predicted by performing an acceleration test based on the Arrhenius equation.

• Geosciences Journal
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• v.22 no.6
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• pp.1041-1052
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• 2018

A single-well push-drift-pull tracer test using two different tracers ($SF_6$ and salt) was performed at the Environmental Impact Test (EIT) site to determine suitable locations for monitoring wells and arrange them prior to artificial $CO_2$ injection and leak tests. Local-scale estimates of hydraulic properties (linear groundwater velocity and effective porosity) were obtained at the study site by the tracer test with two tracers. The mass recovery percentage of the volatile tracer ($SF_6$) was lower than that of the non-volatile tracer (salt) and increased drift time may make degassing of $SF_6$ intensified. The $CO_2$ leakage monitoring results for both unsaturated and saturated zones suggest that the $CO_2$ monitoring points should be located near points at which a high concentration gradient is expected. Based on the estimated hydraulic properties and tracer mass recovery rates, an optimal $CO_2$ monitoring network including boreholes for monitoring the unsaturated zone was constructed at the study site.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.78-83
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• 2004

Environmental fatigue crack propagation of CF8M and CF8A steels used in the domestic PWR were investigated on the simulated PWR condition(Temperature: $316^{\circ}C$, Pressure: 15MPa). The test equipment for environmental fatigue(high temperature-high pressure loop, autoclave, load frame, measurement system) were designed. As-received and 60-year aged specimens were used in the test. To compare with environmental fatigue test, another test was performed in the air condition. The fracture surface of specimens were difficult to verify the fracture modes such as striation, intergranular crack and cleavage and so on. As the ferrite content of CF8M is increased, more particles covered fracture surface were peeled.

• Journal of the Korean GEO-environmental Society
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• v.6 no.3
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• pp.17-23
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• 2005

In Korea, the production of reclaimed concrete materials has been increased due to the increase in the concrete structures taken down every year. The reclaimed concrete materials have been reused as road materials. However, the studies on their mechanical and environmental properties have been very limited. The recycled rate of the materials is currently low in Korea. This paper presents the investigation of mechanical and environmental properties of the reclaimed concrete materials, as well as the comparisons with those of gravel. For the evaluation of the mechanical and environmental characteristics, following tests were conducted on both reclamed materials and gravel; liquid limit, plasticity index, CBR, sand equivalent test, abrasion test, pH test, and column leaching test. The test results showed that the reclaimed concretes satisfy the requirements for use as roadbase, subbase, and subgrade materials, except base materials. The pH of reclaimed concrete materials was less than 11 and the leaching test results satisfied the regulatory requirement of Waste Management Act in Korea. Based on the investigations, it appears that the reclaimed concrete materials are environmentally safe and applicable for use as road materials.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.171-175
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• 2007

Indigenous species means a species that is likely, due to historical presence, to occur at a specified site for some portion of its life span. Therefore, indigenous species can be useful as an indicator to assess environmental risk caused by hazardous chemicals in a specific site. So far a few toxicity studies using freshwater species which are indigenous to Korea have been carried out. In this study, a freshwater shrimp (Neocardina denticulata) indigenous to Korea was used for acute toxicity test of heavy metals. Neocardina denticulata were exposed to cadmium chloride $(CdCl_2)$, copper chloride $(CuCl_2)$ and zinc chloride $(ZnCl_2)$ using automatic flow-through system for 96 hours. The 96h LC50s were calculated as 0.043 $(0.042{\sim}0.045)mg\;CdCl_2/L,\;0.104(0.098{\sim}0.113)mg\; CuCl_2/L\;and\;2.021\;(1.633{\sim}2.594)mg\;ZnCl_2/L$. When compaired with some international standard species such as medaka(Oryzias latipes), Neocardina denticulata had high sensitivity. Therefore, this study suggested that Neocardina denticulata have possibilities for a sensitive test species to test heavy metal toxicity in aqua-system.