• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.777-783
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• 2003

The mechanical properties of B$_4$C/Al composites normally depend on the species and quantity of reaction products between B$_4$C and Al and then the control of reaction products is necessary to make desirable composites for lightweight advanced or armor materials. TiB$_2$ is chemically inert with aluminum and has a lower contact angle (85$^{\circ}$ at 100$0^{\circ}C$) to liquid aluminum than B$_4$C. Thus, TiB$_2$ coating on B$_4$C may lower infiltration temperature of aluminum when the B$_4$C/Al composites is fabricated by infiltration process. In this study, the effects of TiB$_2$ on the microstructure and mechanical properties of the B$_4$C/Al composites have been investigated. TiB$_2$ coated B$_4$C powder was prepared using the sol-gel technique. It was found that the B$_4$C surface is homogeneously covered with TiB$_2$ having a particles size of 20-50 nm. While the B$_4$C/Al composites prepared by infiltration after TiB$_2$ coating had 17 wt% of unreacted Al, on the other hand, the B$_4$C/Al composites without coating included 14 wt% of Al. As a result, the composites infiltrated after the coating showed higher fracture toughness and lower hardness. This strongly suggests that TiB$_2$ not only lowers the infiltration temperature, but also inhibits the reaction between B$_4$C and Al.

• Journal of The Korean Association of Information Education
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• v.5 no.2
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• pp.240-257
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• 2001

Although many attempts have been made to use the Internet for educational purposes, not many attempts have achieved their goals. Such failure is mainly due to the lack of understanding on the way to use the Internet. The goal of this research is to investigate the potentiality of the Project-Based Learning approach using the Internet(NetPBL) and the ways to utilize the NetPBL. The NetPBL can be utilized through various activities such as keypals, mentoring, use of resources, cooperative learning, publishing, survey and data analysis, cooperative problem solving, simulation, and social action. Such diversity of the NetPBL can create a problem-based, context-based and learner-centered environment, which takes various types of the Internet use. In spite of such potentiality, little is known on how to implement the NetPBL. On this point, this research attempts to synthesize instructional strategies to implement the NetPBL at the macro and the micro level. At the macro level, instructional process is divided into four steps such as plan, preparation, implementation and closure, and some instructional suggestions are made for each step. At the micro level, detailed instructional strategies are suggested for the facilitation of self-directed learning and cooperative learning.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2349-2360
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• 2000

In medical image processing, if new technologies arc developed, they arc applied to real clinical cases. The results are to be analyzed by doctors to improve the new technologies. So, it is important for doctors to have a tool that helps the doctors in applying the new technologies to clinical cases and analyzing the clinical results. In this paper, we design and implement a visual programming environment where non-programming experts, such as medical doctors, can easily compose a medical image processing application program. A set of image processing functions are implemented and represented as icons. Thc user selects functions by clicking correslxmding icons. The users can easily find necessary' functions from the visualized library. A user selects a function from the visualized library and [Jut the function node into a canvas of Visual Programming Interface. The user connects nodes to compose a dataflow diagram. The connected dataflow diagram shows the now of the program. Hyperbolic Tree is helpful in visualizing a set of function icons in a single screen because it provides both the whole stmcture of the function Iihrary and the details of the focused functions at the same time. We also developed a CUI builder where the user interfaces of the medical image processing applications are composed. Therefore. non'programming experts such as physicians can apply new medical image processing algorithms to clinical cases without performing complex computer programming procedures.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.95-103
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• 2018

The purpose of this study was to awareness of dental care services in the elderly long-term care insurance system and retirement preparation of middle-aged people. The survey respondents had a 56.1% saving for old age life, And showed a tendency to they don't like depend on one's family(41.8%), elderly care was intended to use facility services and nursing care. 36.7% of respondents answered "I know a little" about the system. Also, the need for dental care services within the system was high (98.5%), If the service is provided, 92.3% of the respondents said that they would participate, otherwise unrecognized rate of dental care services in long-term care insurance was 85.2%. Therefore, it is necessary to expand the awareness of the part of dental care service in the system. The results of this study can be used as basic data for the improvement of the system of dental care services in long-term care insurance for elderly.

• The Korean Journal of Ecology
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• v.17 no.1
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• pp.23-35
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• 1994

To investigate phytotoxic substances in Artemisia argyi, the donor plant, and their biological activities, seed germination and seedling growth of receptor plants such as Arundinella hirta, Echinochloa crus-galli, Rumex crispus and Lactuca sativa were examined at different concentrations of aqueous extracts of the donor plant. Germination of four receptor species was inhibited by the extracts, while seedling growth was decreased to a lesser degree than in the germintion test. Germination, seedling growth and dry weight growth of Achyranthes japonica grown in pot were proportionally inhibited by the extracts. Volatile substances emitted from A, argi plant caused slight inhibition in the germination and seedling growth of the receptor species. Essential oil of the plant extracted by Karlsruker's apparatus inhibited growth of microorganisms and callus growth of Pinellia ternata and Oryza sativa. The GC /MS method was employed for analysis and identification of allelochemicals from A. argyi leaves. Sixty-one chemical substances such as a-pinene, camphene, 1. 8-cineol, etc. were identified from essential oil of A. argyi. The results of this experiment on seed germination, seedling growth, microorganism culture and tissue culture indicated that naturally occurring chemical substances from A. argyi would be responsible for the growth inhibition of plants studied.

• Journal of The Korean Association For Science Education
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• v.31 no.2
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• pp.239-255
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• 2011

As a case study on the use of coteaching in science instruction for science-gifted elementary students, this paper analyzed the characteristics of coteaching science instruction for science-gifted elementary students by plan, performance, and reflection-evaluation stages of the classes. To do this, we observed two teachers' coteaching science instruction for science-gifted elementary students during twelve classes and analyzed the taped videos, their journals, and the transcripts for in-depth interviews with them. The results indicated that the characteristics of the coteaching science instruction, in the planning stage of the classes, showed improvement in the quality of the sciencegifted education programs, the reduction of the psychological burdens of developing the programs, and some efficiency loss due to the joint preparation of the classes. The characteristics in the performance stage of the classes include the seamless progression of the classes through the division of roles, the increase of the students' opportunity to explore, the supplement of the teachers' inadequate descriptions and the overlooked contents, the increase of the interaction between teachers and students and/or the interaction among students, the reduction of the risk of accidents in experiments, and the reduction of the responsibility for teaching. Finally, the characteristics in the reflectionevaluation stage of the classes could be attributed to the diversity of the evaluation viewpoints, the increase of the learning opportunities to develop the teaching professionalism, and the increase of the fear for assessing my own classes.

• Culinary science and hospitality research
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• v.18 no.3
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• pp.1-17
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• 2012

This study was planned for an empirical review of foodservice operation in expressway rest areas for a menu strategy targeting staff and customers. The results were as follows. Main foodservice category included 10-30 items of Korean dishes. The needs for having branded foodservice menu in rest areas were high in fusion/fast foods, snack/ready-made and beverages. Employment of professional cooks in rest areas was low (10-30%), and the most important factor was 'taste' when cooking Korean foods. Foreigners preferred fusion/fast foods and snack/ready-made foods to Korean food, beverages and Japanese/Chinese foods, and most of the foreigners ordered food with 'no question'(55.5%) or 'some questions'(34.8%). Rest area staff prepared some photos/pictures of foods (80-100%) for menu comprehension, but the accuracy of menu transcription was very low. Customers used a rest area once or twice, stayed for 10-20 min(43.6%)/20-30 min(38.6%), visited by car(77.7%) to relax and use toilets(61.6%) on average. Favorite food and snacks were Korean(32.7%) and ready made/snacks(33.0%), and they spent 5,000-10,000 won(51.3%), 3,000-5,000 won(25.8%) on them. Customer satisfaction with rest areas was 'average' regardless of gender, age, education levels and jobs. With this analysis, we should prepare an efficient menu strategy for customer satisfaction and plans for analyzing problems along with alternatives.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1732-1739
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• 2009

The purpose of this study was to analyze factors that influence consumption pattern of snacks of middle school students. The subjects of study were 607 middle school students (male: 316, female: 291) in Ilsan area. The subjects were surveyed by a self-administered questionnaire about anthropometrics, mother's employed status, parents' education level, and snack consumption pattern. Male students showed higher consumption in 'milk and milk products' (p<0.05), 'instant noodles' (p<0.01), and 'cereal' (p<0.05). In the other hand, female students showed higher consumption in 'biscuits, cookies' (p<0.01) and 'candy and chocolates' (p<0.01). Subjects in underweight group showed higher frequency in the consumption of 'biscuits, cookies' (p<0.05) and 'candy and chocolates' (p<0.001) compared with normal weight or overweight subjects. The subjects with mother not having a job showed higher consumption of snacks under controlling parents (p<0.001), and higher consumption in 'fruit and fruit juice' (p<0.05) and 'milk and milk products' (p<0.01) compared to the subjects with mother having a job. The subjects with parents having higher education level showed higher of consumption in 'fast food'. These results suggest that general characteristics of the subjects and characteristics of family environment may affect consumption pattern of snacks in middle school students.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1740-1745
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• 2009

In this study, effect of resveratrol concentration on wine taste was investigated. Content of resveratrol in 14 different wines were quantified using HPLC. The resveratrol concentrations in the Australian wine samples (grape species: Syrah) with 3 vintage years were analyzed and different concentrations of resveratrol were observed (2.89-3.84 mg/L). Variation in wine grape species with the same wine manufacturer (Chile, 2006) and variation in different manufacturing country of origin with same wine grape species (Cabernet Sauvignon, 2006) also produced the variations in resveratrol concentration. The preference analysis (color, aroma, taste,astringency and overall acceptability) of the sample wines were determined by 15 panelists using 5-point hedonic scale. When the analysis results of the resveratrol concentrations in the sample wines were compared with the preference analysis of sample wines, the resveratrol concentration in the wine produced the positive effects in the wine preference analysis in the factors of aroma, taste and color.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.5
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• pp.153-164
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• 2016

It is critical for adolescents to foster self-efficacy, creativity, and adventurous spirit as well as plans for appropriate career path in order to become good members of society. During this adolescent period, newspapers will be a good learning material as they deliver various and timely information in refined language. In this paper, we analyzed the impact of NIE on development of self-efficacy, awareness of career path, and entrepreneurship through comparing adolescents who regularly read newspapers with those who do not. We came up with the following result after analysis of surveys (with a sample size of 283) that targeted middle school and higher grade elementary school students across Korea. We confirmed that reading newspapers has a positive impact on development of self-efficacy, awareness of career path, and entrepreneurship. More specifically, reading newspapers regularly has a positive impact on development of self-efficacy that subsequently has a positive impact on development of awareness of career path and entrepreneurship. Therefore, we found that simply reading newspapers regularly has a positive impact on development of self-efficacy, awareness of career path, and entrepreneurship with no special programs utilizing the newspapers. This is because various information and opinions in newspapers help adolescents to develop their own views, improve understanding and awareness of career, and development of sociality including creativity and adventurous spirit. There is the meaning as the first research that this research checks what the NIE of the adolescents affects the positive impact to not only the self-efficacy and career awareness but also entrepreneurship.