• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.271-284
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• 2014

The objectives of this research were to analyse the microhabitat of Cobitis choii which is designated as an endangered fish species (I) and national monument species in Korea (No. 454), and provide valuable information of suitable replacement habitat in the future for a conservation of the population with rapid decreases by environmental pollution. Sampling and microhabitat analysis in three streams such as Baekgok, Yugu and Gap Stream, known as one of the least habitats in Korea showed that the mean number of Cobitis choii observed was 2.6. This result indicated that the richness was too low, so the species conservation was very urgent. Optimal physical microhabitat of the population was determined as environmental conditions with > 60% sand with 1 mm particle size, optimal water depth of 20 - 60 cm in the habitats, and the optimal current velocity of < 0.4 m/s. Under the circumstances of the microhabitat, optimal water volume (discharge) was 0 - 2 m3/s in the each sectional analysis and this reach was mainly composed of the stream section with intermittant slow runs and pools. These microhabitats were largely disturbed by physical modifications of habitat and chemical pollutions due to direct influences of nutrient-rich water inputs from the urban area and intensive agricultural pollutants. For these reasons, optimal habitat replacement are required in the future for the conservation of the species.

• Journal of Educational Research in Mathematics
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• v.18 no.1
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• pp.103-121
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• 2008

The primary purpose of this study was to gather knowledge about $5^{th},\;6^{th},\;and\;7^{th}$ graders' proportional reasoning ability by investigating their reactions and use of strategies when encounting proportional or nonproportional problems, and then to raise issues concerning instructional methods related to proportion. A descriptive study through pencil-and-paper tests was conducted. The tests consisted of 12 questions, which included 8 proportional questions and 4 nonproportional questions. The following conclusions were drawn from the results obtained in this study. First, for a deeper understanding of the ratio, textbooks should treat numerical comparison problems and qualitative prediction and comparison problems together with missing-value problems. Second, when solving missing-value problems, students correctly answered direct-proportion questions but failed to correctly answer inverse-proportion questions. This result highlights the need for a more intensive curriculum to handle inverse-proportion. In particular, students need to experience inverse-relationships more often. Third, qualitative reasoning tends to be a more general norm than quantitative reasoning. Moreover, the former could be the cornerstone of proportional reasoning, and for this reason, qualitative reasoning should be emphasized before proportional reasoning. Forth, when dealing with nonproportional problems about 34% of students made proportional errors because they focused on numerical structure instead of comprehending the overall relationship. In order to overcome such errors, qualitative reasoning should be emphasized. Before solving proportional problems, students must be enriched by experiences that include dealing with direct and inverse proportion problems as well as nonproportional situational problems. This will result in the ability to accurately recognize a proportional situation.

• School Mathematics
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• v.11 no.2
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• pp.317-333
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• 2009

The purpose of this study was to examine the thinking characteristics of mathematically gifted elementary school students in the process of modified prize-sharing problem solving and each student's thinking changes in the middle of discussion. To determine the relevance of the research task, 19 sixth graders enrolled in a local joint gifted class received instruction, and then 49 students took lessons. Out of them, 19 students attended a gifted education institution affiliated to local educational authorities, and 15 were in their fourth to sixth grades at a beginner's class in a science gifted education center affiliated to a university. 15 were in their fifth and sixth grades at an enrichment class in the same center. Two or three students who seemed to be highly attentive and express themselves clearly were selected from each group. Their behavioral and teaming characteristics were checked, and then an intensive observational case study was conducted with the help of an assistant researcher by videotaping their classes and having an interview. As a result of analyzing their thinking in the course of solving the modified prize-sharing problem, there were common denominators and differences among the student groups investigated, and each student was very distinctive in terms of problem-solving process and thinking level as well.

• Korean Journal of Environmental Agriculture
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• v.24 no.3
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• pp.295-302
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• 2005

The nitrogen (N) balance in Korea during 1985-1997 was calculated according to the surface balance method of the PARCOM guidelines and compared with Japanese N balance. The some differences were founded in the coefficients used on calculating N balance in two nations. Of the important parameters, which can make a big difference in balance, N input by organic fertilizers was not included in Korea different with Japanese, due to absence of reliable statistics and then made lower the input. Nitrogen destruction rate from livestock manure was adjusted differently with 15% in Korea but 28% in Japan. There was some difference in the conversion factors of livestock number into manure N quantity in two nations, but the gap was ignoble scale except beef cattle. Our manure N production rate of beef cattle might be evaluated to be so lower than Japanese. Biological N fixation by pulses was very higher in Korea than in Japan but scarcely affect the increase of total N input, due to small cultivation area. In contrast, N fixation rate by free-living organisms in Korean and Japanese wet paddies showed the big difference with 7.6 and $37.0kg\;ha^{-1}\;yr^{-1}$, respectively, and therefore $29.4kg\;ha^{-1}\;yr^{-1}$ of nitrogen was estimated to be more inputted in Japan. Although there are many points to be more specified and improved, still, Korean N balance was very high with $250-257kg\;ha^{-1}$ in the mid of 1990s, which was the second highest level in OECD countries and furthermore increased continuously during the investigation. In contrast in Japan, which has similar fanning system with Korea, N balance was lower with $130-158kg\;ha^{-1}$ and has decreased continuously since 1993. This high N balance was mainly due to a high usage of chemical fertilizers in our intensive fanning system and the fast increment of livestock feeding. Therefore, the more active action to decrease chemical fertilizer utilization and reduce livestock feeding density is required in the government and farmer sides.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.248-253
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• 2007

This research investigated whether exposure of diesel exhaust particulate (DEP) and particulate matter (PM) effects on airway remodeling in asthma induced Balb/c and IL-10 knock out (KO) mouse. Mice were sensitized with intraperitoneal injection with ovalbumin, followed by challenges with intranasal ovalbumin. After that mice placed in inhalation chamber and exposed to DEP and $PM(10\;mg/m^3)$. The evidence of airway remodeling was assessed by masson's trichrome staining and PAS staining. The stainability of masson's trichrome and PAS reaction were increased in asthma-induced Baltic mice groups compared with control mice groups. More intensive stainability for masson's trichrome and PAS were appeared in the asthma-induced DEP and PM-exposed groups than asthama-induced groups. But, not significantly increased subepithelial fibrosis and the nember of goblet cell hyperplasia in asthma-induced IL-10 KO mice groups and asthma-induced+DEP and PM-exposed IL-10 KO mice than IL-10 KO mice groups. These results indirectly suggesting that exposure to DEP and PM in asthmatic patients might be aggravate clinical symptoms and IL-10 which seems to play a central role in allergic asthma. In conclusion, DEP and PM exposure might have additive effects on the ovalbumin- induced asthma in a murine model.

• Fire Science and Engineering
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• v.32 no.5
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• pp.95-104
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• 2018

The 119 emergency medical services(EMS) personnel studied in this research are constantly exposed to traumatic events, which can lead to a variety of psychosocial problems and poor quality of life. In this study, we examined the effects of the Mind Subtraction Meditation Program on post-traumatic growth and resilience of 119 EMS personnel. In this study, we measured the conditions of 26 EMS personnel of A firefighting headquarters based on post-traumatic growth and resilience before and after implementing the short-term intensive for 2 nights and 3 days in $201^*$. The results showed that there was a significant increase in post-traumatic growth from $2.85({\pm}.67)$ to $3.60({\pm}.72)$ and resilience from $2.45({\pm}.39)$ to $2.83({\pm}.48)$ of the subjects between before and after the Mind Subtraction Meditation. In conclusion, the Mind Subtraction Meditation Program was effective in improving the posttraumatic growth and resilience of 119 EMS personnel. Therefore, Mind Subtraction Meditation Program could be proposed as a mental health promotion program for EMS personnel.

• Journal of Gifted/Talented Education
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• v.22 no.3
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• pp.551-573
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• 2012

Educating gifted students in invention is a totally new area for researchers as well as educators. Establishing the theoretical concept of the gifted in invention has been a challenging task to many education researchers in Korea for last several years. This study was conducted to understand characteristics of the gifted in invention with the eventual purpose to conceptualize 'giftedness in invention.' The Future Mind by Gardner was adopted as the frame for categorizing the characteristics of the gifted in invention. Based on Five Minds, this study listed 25 factors with their 80 characteristics after intensive literature review and field surveys. The findings of this study are expected to contribute to establishing the theoretical base of educating the gifted in invention, to identifying gifted youngsters to be great inventors, and to designing the educational programs for them.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.500-511
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• 2012

Recently, use frequency for traffic information which provides shortest paths and traffic condition is increasing. Specially, in the survey, it is shown that users prefer internet portal sites which can be used the most easily among traffic information media. But, there are not many verification systems for traffic information contents of internet portal sites which collect and provide information than traffic information contents which are provided by public service. The purpose of this study is to investigate real accuracy and accuracy felt by users about information provided by portal sites. Therefore, in this research we verified accuracy of information by portal site with real field data and investigate real usage about contents and experienced accuracy by users through survey. Also, users' expectation and satisfaction were surveyed and the contents to be improved were selected by using IPA technique. By the result of accuracy verification by field data using portable DSRC(Dedicated Short Range Communication) devices, it is shown that average error was 14~32% and sometimes very high rate. Also, it is shown that 28.3 % of total respondents prefers the information by portal sites and 50 % of total respondents felt that contents of traffic information by portal sites are not accurate. Real-time traffic condition was selected as the most inaccurate one among all contents of traffic information and it was analyzed that intensive efforts for improving information about real-time traffic condition are needed.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.35-43
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• 2016

With the development of construction technology, constructions of dam and levee (dike) as well as the environmental problems are becoming issues. Recently, many countries have tried to develop and used CSG (Cemented Sand and Gravel), which needs fewer requirements than others in aggregates, constructability and ground condition during the dam construction. Mixing up with small amount of cement, CSG is able to increase the strength and proceed accelerated construction without artificial gradation adjustment of riverbed aggregate and crushed rock on construction site. Thus, CSG can minimize environmental damage resulted from quarries mining and reduce cost of construction. Unlike heat of hydration condition that regular concrete usually met, CSG exposes to repeated dry-wet and freezing and thawing environment. Thus, consider the importance of structure of dam or levee, intensive study on the durability of CSG is needed. In this study, freezing and thawing experiment was carried out to evaluate the durability of CSG. In results, the durability factor of CSG is 30~40 or >40 when the amount of cement is $0.4{\sim}0.6kN/m^3$ or $0.8{\sim}1.0kN/m^3$, respectively. The unconfined compressive strength is reduced to 30~50% or 40~70% when the amount of cement is $0.4{\sim}0.6kN/m^3$ or $0.8{\sim}1.0kN/m^3$, respectively. Taken together, the strength and durability of CSG is reliable when the amount of cement is over $0.8kN/m^3$.

• Journal of the Korean Geographical Society
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• v.44 no.4
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• pp.463-480
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• 2009

The weathering properties and provenance of loess-paleosol sequence deposited on gravel layer of river terrace in Bongdong-eup, Wangju-gun, Jeonbuk Province are examined using soil analysis, magnetic susceptibility measurement, grain size and element analysis. The Bongdong section consists of, from top to bottom, Layer 1(paleosol), Layer 2(loess), Layer 3(paleosol) and the gravel layer of river terrace. The magnetic susceptibility values show the systematic variations in the sequence and the results of grain size analysis reveal that the sequence was deposited by not fluvial or slope process, but eolian process, and that contains finer materials than the Daecheon loess and Chinese Loess Plateau. Among the results of soil analysis, organic contents indicate systematic variations similar to the magnetic susceptibility. The wet soil colors further reflect the characteristics of the sequence rather than the dry soil colors. Based on the analytical results of major and rare earth elements, the eolian materials contained in the sequence were deposited by the materials originated from the areas where the Chinese Loess Plateau has been originated or the reworked materials from the Chinese Loess Plateau, and after the depositions, the materials experienced the intensive chemical weathering under the humid-warm climatic conditions in the Korean Peninsula.