• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.463-476
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• 2017

Climate change is considered as the greatest threat to our future and descendants. The Korean government has set a target for 2030 to reduce emission of greenhouse gases (GHGs) by 37% from the business-as-usual levels which are projected to reach 851 million metric tons of $CO_2eq$ (Carbon dioxide equivalent). In Korea, GHGs emission from agriculture account for almost 3.1% of the total of anthropogenic GHGs. The GHGs emitted from agricultural land are largely classified into three types: carbon dioxide ($CO_2$), methane ($CH_4$), and nitrous oxide ($N_2O$). In Korea, rice paddies are one of the largest agricultural $CH_4$ sources. In order to analyze domestic research trends related to $CH_4$ emission from rice paddies, 93 academic publications including peer reviewed journals, books, working papers, reports, etc., published from 1995 to September 2017, were critically reviewed. The results were classified according to the research purposes. $CH_4$ characteristics and assessment were found to account for approximately 65.9% of the research trends, development of $CH_4$ emission factors for 9.5%, $CH_4$ emission reduction technology for 14.8%, and $CH_4$ emission modeling for 6.3%, etc. A number of research related to $CH_4$ emission characteristics and assessment have been studied in recent years, whereas further study on $CH_4$ emission factors are required to determine an accurate country-specific GHG emission from rice paddies. Future research should be directed toward both studies for reducing the release of $CH_4$ from rice paddies to the atmosphere and the understanding of the major controlling factors affecting $CH_4$ emission.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.300-307
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• 2016

The development of computer-based information technology has led to the quantitative and qualitative growth of social media which have two sides; a positive one such as the generation and sharing of information and a negative one which includes cyber plagiarism and cyber bullying. This study seeks to understand which factors can lead to cyber plagiarism, which is the most prevalent form of unethical cyber behavior. We expected that the intrinsic and extrinsic motivations for using social media would have different effects on unethical cyber intention and that this relation between motivation and cyber unethical behavior would be moderated by the subjective norm. In order to obtain a better understanding of the relationships among the individual motivation, unethical cyber intention, and cyber plagiarism, information was obtained from 564 social media users. The respondents provided details of their experiences and attitudes regarding social media usage behavior and unethical cyber behavior. The results confirmed that extrinsic motivation significantly increases unethical intention and further leads to high levels of cyber plagiarism. The subjective norm plays a moderating role in the relationships between extrinsic motivation and unethical cyber intention. Based on the results, the theoretical and practical implications of the research findings are discussed, and recommendations for future research are provided.

• Journal of Distribution Science
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• v.14 no.2
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• pp.123-133
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• 2016

Purpose - Understanding how service convenience drives shopping performance is imperative for retailers such as department and large discount stores. Retailers have to enhance shopping productivity by reducing the costs of shopping, as convenience triggers customers' perceived shopping value, leading to customer satisfaction, and ultimately patronage behavior. Consumers, generally considering time as a scarce resource, are more sensitive to the time costs of tasks in regard to shopping trip, differently from forming perceptions of convenience in time orientation. Therefore, this study attempts to examine the moderating effects of consumers' time orientation on the relationships among service convenience of retailers and shopping performances such as shopping value and service performances. Research design, data, and methodology - The department and discount store chains were chosen as the point of analysis in this study. Data were collected from a survey of real-life consumers and all respondents were screened to ensure only those who had visited in the department and discount store chains within past six month prior to the day of data collection. Out of 600 self-reported surveys that were distributed, a total of 530 responses were returned and after excluding 20 incomplete responses, the final sample size was 510. The three hypotheses were proposed and tested in this study. The one hypothesis was on the moderating effects of time orientation for the effects of service convenience on shopping value (hedonic and utilitarian shopping value). The other two hypotheses were on the comparisons between high and low time-oriented customers with the effects in shopping value from service performance. Hierarchical moderated regression analysis was used to test the hypotheses. Results - The results suggest that the effect of service convenience on utilitarian shopping value and the positive effect of utilitarian shopping value on customer satisfaction are greater in low time orientation than high time orientation customers. Conversely, when customers are highly oriented toward time, the effects of hedonic shopping value on customer satisfaction and revisit intention are greater than for customers who are lowly oriented toward time. Conclusions - This study has two-fold significance. First, this study contributes to the consumer behavior and services marketing literature by incorporating customers' time orientation into the service convenience-shopping performance. Although the effect of service convenience on shopping performance might differ from customers' perceptions concerning shopping, there has been little investigation or comparison between customers' perception on time. This study is a first attempt to consider how the effects of service convenience on shopping value and service performance vary with differing levels of customers' time orientation. This study advances prior studies by showing that the service convenience-shopping value and service convenience-service performance relationships vary across different combinations of the customer's time orientation. The findings of this study suggest that the retailers need to enhance the experiential aspects of the stores for their high time-oriented customers. Conversely, for the low time-oriented customers, the retailers should boost the visual distinctiveness and ease of store navigation.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.146-152
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• 2001

Purpose : To investigate the regulation of apoptosis and cell cycle in mouse brain irradiation. Materials and Methods : 8-week old male mice, C57B1/6J were given whole body $\gamma-radiation$ with a single dose of 25 Gy using Cobalt 60 irradiator. At different times 1, 2, 4, 8 and 24hr after irradiation, mice were killed and brain tissues were collected. Apoptotic cells were scored by TUNEL assay. Expression of p53, Bcl-2, and Bax and cell cycle regulating molecules; cyclins Bl, Dl, E and cdk2, cdk4, $p34^{cdc2}$ were analysed by Western blotting. Cell cycle was analysed by Flow cytometry. Results : The peak of radiation induced apoptosis is shown at 8 hour after radiation. With a single 25 Gy irradiation, the peak of apoptotic index in C57B1/6J is $24.0{\pm}0.25$ (p<0.05) at 8 hour after radiation. Radiation upregulated the expression of p53/tubulin, Bax/tubulin, and Bcl-2/tubulin with 1.3, 1.1 and 1.45 fold increase, respectively were shown at the peak level at 8 hour after radiation. The levels of cell cycle regulating molecules after radiation are not changed significantly except cyclin D1 with 1.3 fold increase. Fractions of Go-Gl, G2-M and S phase in the cell cycle does not specific changes by time. Conclusion : In mouse brain tissue, radiation induced apoptosis is particularly shown in a specific area, subependyma. These results and lack of radiation induced changes in cell cycle ofter better understanding of radiation response of noraml brain tissue.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.92-106
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• 2004

Elemental dry deposition fluxes were measured using dry deposition plates from March to June 1998 in Seoul, Korea. During this spring sampling period several yellow sand events characterized by long-range transport from China and Mongolia impacted the area. Understanding the impact of yellow-sand events on atmospheric dry deposition is critical to managing the heavy metal levels in the environment in Korea. In this study, the measured flux of a primarily crustal metal, Al and an anthropogenic metal, Pb was used with two hybrid receptor models, potential source contribution function (PSCF) and residence time weighted concentration (RTWC) for locating sources of heavy metals associated with atmospheric dry deposition fluxes during the yellow-sand events in Seoul, Korea. The PSCF using a criterion value of the 75th percentile of the measured dry deposition fluxes and RTWC results using the measured elemental dry deposition fluxes agreed well and consistently showed that there were large potential source areas in the Gobi Desert in China and Mongolia and industrial areas near Tianjin, Tangshan, and Shenyang in China. Major industrial areas of Shenyang, Fushun, and Anshan, the Central China loess plateau, the Gobi Desert, and the Alaskan semi-desert in China were identified to be major source areas for the measured Pb flux in Seoul, Korea. For Al, the main industrial areas of Tangshan, Tianjin and Beijing, the Gobi Desert, the Alashan semi-desert, and the Central China loess plateau were found to be the major source areas. These results indicate that both anthropogenic sources such as industrial areas and natural sources such as deserts contribute to the high dry deposition fluxes of both Pb and Al in Seoul, Korea during yellow-sand events. RTWC resolved several high potential source areas. Modeling results indicated that the long-range transport of Al and Pb from China during yellow-sand events as well as non yellow-sand spring daytimes increased atmospheric dry deposition of heavy metals in Korea.

• Journal of the Korean Home Economics Association
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• v.47 no.3
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• pp.55-65
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• 2009

By definition, smart clothing describes a garment whose functionality is enhanced by technological advancements in order to ease one’'s lifestyle. To know user’'s understanding and needs, the research had consisted of brainstorming sessions, personal interviews, focus group meeting, and a series of content analyses. Ten of the interview subjects and focus group panel were found by contacting women aged 56-64 in the Ithaca community, NY. They were prompted with general questions on style choices for their lifestyles and age group and then presented with two examples of smart clothing to discuss and critique. Meanwhile, the other three interview subjects, located outside of the Ithaca community, were aged either above or below the targeted bracket. These subjects were interviewed as a method of comparison on multiple levels. Findings had shown that there was indeed a need for smart clothing amongst the increasingly populated demographic of older women: devices to help one’'s body temperature regulation and vision problem, and well-designed clothing. However, the functionalities must be carefully constructed and conveyed in order to be taken seriously by the mainstream consumer market. Once successfully designed, the smart clothing will ideally create a greater sense of autonomy for older women.

• Journal of The Korean Association For Science Education
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• v.23 no.3
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• pp.254-264
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• 2003

Researches on laboratory work show that students often achieve little meaningful learning through laboratory work. One reason for this failure is that students often do not know the different types of laboratory work and the 'purposes' of them. Therefore, this study investigated middle school student' ideas about the purposes of laboratory work. To seventh grade students(n=147) of middle school in Seoul, Korea, we asked (Question 1) "Why do scientists do laboratory work?" and (Question 2) "Why do you do laboratory work in science classes?" It was required a short essay including the reasons and examples of them. From the results, it was found that 56.8% of the students had ideas that scientists do laboratory work for discovering new facts or inventing something, and 82.9% of the students responded that they do laboratory work for understanding and memorizing the contents of science textbook. In addition, the differences according to gender and to school achievement level, and the relationship between the ideas about scientists' laboratory work and about school science laboratory work were examined. The results showed that boys responded 'social usefulness' more frequently than girl, while girls mentioned 'personal pleasure' more frequently than boys in relation to the purposes of scientists' laboratory work(p<.05). According to the achievement level, it was founded that 'middle' level students replied 'to remember' more frequently than high and low levels in relation to school science laboratory work. Finally, students who had ideas that scientists do laboratory work for verifying a theory had the similar ideas about school science laboratory work. In conclusion, students are lack of diverse and proper views about laboratory work. It is recommended that teacher need to make clear the purpose of laboratory work and help students to understand of it.

• Korean Journal of Social Welfare
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• v.58 no.4
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• pp.371-392
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• 2006

The studies and concerns of social rights and the security of social rights continue steadily, and extend there range and realms. But not only ideological and political threats on them but also critical views still are widespread. Therefore we need adequate researches on the characteristics of social rights and the meanings of the security of social rights, which are more fundamental. So this study was intended for more precise understanding on social rights and the meanings of the security of social rights through researches on the characteristics of social rights. The characteristics of social rights which this study researched are rights and duties, citizenship rights and social justice, and methodology and ideology. Through this research, I discussed justness of social rights and clarified the security of social rights not to be defined categorically but to be procedural concept. I argued that security of social rights is necessary to realize other citizenship rights such as civil rights, political rights, and I discussed this has to be considered dimension of social justice. And I discussed the necessity and the levels of distribution, which are accomplished not to dimension of simple social security and social welfare benefits but to dimension of human liberties, rights, and equalities.

• Composites Research
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• v.16 no.4
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• pp.66-73
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• 2003

The importance of understanding the response of structural composites to impact and CAI cannot be overstated to develop analytical models for impact damage and CAI strength predictions. This paper presents experimental findings observed from quasi-static lateral load tests, low velocity impact tests. CAI strength and open hole compressive strength tests using 3 mm thick composite plates($[45/-45/0/90]_{3s}$- IM7/8552). The conclusion is drawn that damage areas for both quasi-static lateral load and impact tests are similar and the curves of several drop weight impacts with varying energy levels(between 5.4 J and 18.7 J) follow the static curve well. In addition, at a given energy the peak force is in good agreement between the static and impact cases. It is identified that the failure behaviour of the specimens from the CAI strength tests was very similar to that observed in laminated plates with open holes under compression loading. The residual strengths art: in good agreement with the measured open hole compressive strengths. considering the impact damage site area, an equivalent hole. The experimental findings suggest that simple analytical models for the prediction of impact damage area and CAI strength can be developed on the basis of the failure mechanism observed from the experimental tests.

• Journal of Educational Research in Mathematics
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• v.25 no.4
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• pp.657-673
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• 2015

In this study, we are interested in the teachers' MCK about '$N{\div}0$' and MPCK in relation to the proper ways to teach it. Even though '$N{\div}0$' is not on the current curriculum and textbooks of elementary school mathematics, a few students sometimes ask a question about it because the division of the form '$a{\div}b$' is dealt in whole number including 0. Teacher's obvious understanding and appropriate guidance based on students' levels can avoid students' error and have positive effects on their subsequent learning. Therefore, we developed an interview form to investigate teachers' MCK about '$N{\div}0$' and MPCK of the proper ways to teach it and carried out individual interviews with 30 elementary school teachers. The results of the analysis of these interviews reveal that some teachers do not have proper MCK about '$N{\div}0$' and many of them have no idea on how to teach their students who are asking about '$N{\div}0$'. Based on our discussion of the results, we suggest some didactical implications.