• The Mathematical Education
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• v.24 no.2
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• pp.48-73
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• 1986

Though the tradition of Korean mathematics since the ancient time up to the 'Enlightenment Period' in the late 19th century had been under the influence of the Chinese mathematics, it strove to develop its own independent of Chinese. However, the fact that it couldn't succeed to form the independent Korean mathematics in spite of many chances under the reign of Kings Sejong, Youngjo, and Joungjo was mainly due to the use of Chinese characters by Koreans. Han-gul (Korean characters) invented by King Sejong had not been used widely as it was called and despised Un-mun and Koreans still used Chinese characters as the only 'true letters' (Jin-suh). The correlation between characters and culture was such that, if Koreans used Han-gul as their official letters, we may have different picture of Korean mathematics. It is quite interesting to note that the mathematics in the 'Enlightenment Period' changed rather smoothly into the Western mathematics at the time when Han-gul was used officially with Chinese characters. In Koryo, the mathematics existed only as a part of the Confucian refinement, not as the object of sincere study. The mathematics in Koryo inherited that of the Unified Shilla without any remarkable development of its own, and the mathematicians were the Inner Officials isolated from the outside world who maintained their positions as specialists amid the turbulence of political changes. They formed a kind of Guild, their posts becoming patrimony. The mathematics in Koryo significant in that they paved the way for that of Chosun through a few books of mathematics such as 'Sanhak-Kyemong', 'Yanghwi-Sanpup' and 'Sangmyung-Sanpup'. King Sejong was quite phenomenal in his policy of promotion of mathematics. King himself was deeply interested in the study, createing an atmosphere in which all the high ranking officials and scholars highly valued mathematics. The sudden development of mathematic culture was mainly due to the personality and capacity of king who took anyone with the mathematic talent into government service regardless of his birth and against the strong opposition of the conservative officials. However, King's view of mathematics never resulted in the true development of mathematics perse and he used it only as an official technique in the tradition way. Korean mathematics in King Sejong's reign was based upon both the natural philosophy in China and the unique geo-political reality of Korean peninsula. The reason why the mathematic culture failed to develop continually against those social background was that the mathematicians were not allowed to play the vital role in that culture, they being only the instrument for the personality or politics of the king. While the learned scholar class sometimes played the important role for the development of the mathematic culture, they often as not became an adamant barrier to it. As the society in Chosun needed the function of mathematics acutely, the mathematicians formed the settled class called Jung-in (Middle-Man). Jung-in was a unique class in Chosun and we can't find its equivalent in China or Japan. These Jung-in mathematician officials lacked tendency to publish their study, since their society was strictly exclusive and their knowledge was very limited. Though they were relatively low class, these mathematicians played very important role in Chosun society. In 'Sil-Hak (the Practical Learning) period' which began in the late 16th century, especially in the reigns of Kings Youngjo and Jungjo, which was called the Renaissance of Chosun, the ambitious policy for the development of science and technology called for. the rapid increase of he number of such technocrats as mathematics, astronomy and medicine. Amid these social changes, the Jung-in mathematicians inevitably became quite ambitious and proud. They tried to explore deeply into mathematics perse beyond the narrow limit of knowledge required for their office. Thus, in this period the mathematics developed rapidly, undergoing very important changes. The characteristic features of the mathematics in this period were: Jung-in mathematicians' active study an publication, the mathematic studies by the renowned scholars of Sil-Hak, joint works by these two classes, their approach to the Western mathematics and their effort to develop Korean mathematics. Toward the 'Enlightenment Period' in the late 19th century, the Western mathematics experienced great difficulty to take its roots in the Peninsula which had been under the strong influence of Confucian ideology and traditional Korean mathematic system. However, with King Kojong's ordinance in 1895, the traditional Korean mathematics influenced by Chinese disappeared from the history of Korean mathematics, as the school system was hanged into the Western style and the Western mathematics was adopted as the only mathematics to be taught at the Schools of various levels. Thus the 'Enlightenment Period' is the period in which Korean mathematics shifted from Chinese into European.

• Journal of The Korean Association For Science Education
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• v.32 no.1
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• pp.160-181
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• 2012

The purpose of this study is to understand raters' errors in rating performance assessments of science inquiry. For this, 60 middle school students performed scientific inquiry about sound propagation and 4 trained raters rated their activity sheets. Variance components estimation for the result of the generalizability analysis for the person, task, rater design, the variance components for rater, rater by person and rater by task are about 25%. Among 4 raters, 2 raters' severity is higher than the other two raters and their severities were stabilized. Four raters' rating agreed with each other in 51 cases among the 240 cases. Through the raters' conferences, the rater error types for 189 disagreed cases were identified as one of three types; different salience, severity, and overlooking. The error type 1, different salience, showed 38% of the disagreed cases. Salient task and salient assessment components are different among the raters. The error type 2, severity, showed 25% and the error type 3, overlooking showed 31%. The error type 2 seemed to have happened when the students responses were on the borders of two levels. Error type 3 seemed to have happened when raters overlooked some important part of students' responses because she or he immersed her or himself in one's own salience. To reduce the above rater errors, raters' conference in salience of task and assesment components are needed before performing the holistic scoring of complex tasks. Also raters need to recognize her/his severity and efforts to keep one's own severity. Multiple raters are needed to prevent the errors from being overlooked. The further studies in raters' tendencies and sources of different interpretations on the rubric are suggested.

• Journal of The Korean Association For Science Education
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• v.34 no.5
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• pp.437-447
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• 2014

Learning progressions (LP), which describe how students may develop more sophisticated understanding over a defined period of time, can inform the design of instructional materials and assessment by providing a coherent, systematic measure of what can be regarded as "level appropriate." We developed LPs for the nature of matter for grades K-16. In order to empirically test Korean students, we revised one of the constructs and associated assessment items based on Korean National Science Standards. The assessment was administered to 124 Korean secondary students to measure their knowledge and submicroscopic representations, and to assign them to a level of learning progression for the particle nature of matter. We characterized the level of students' understanding and models of the particle nature of matter, and described how students interpret various representations of atoms and molecules to explain scientific phenomena. The results revealed that students have difficulties in understanding the relationship between the macroscopic and molecular levels of phenomena, even in high school science. Their difficulties may be attributed to a limited understanding of scientific modeling, a lack of understanding of the models used to represent the particle nature of matter, or limited understanding of the structure of matter. This work will inform assessment and curriculum materials development related to the fundamental relationship between macroscopic, observed phenomena and the behavior of atoms and molecules, and can be used to create individualized learning environments. In addition, the results contribute to scientific research literature on learning progressions on the nature of matter.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1497-1507
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• 2016

The purpose of this study was to conduct importance and performance analysis of sanitation management in workers at small and medium foodservice industries using HACCP prerequisites. Questionnaires were distributed to 500 small and medium foodservice industry workers in Seoul Gyeonggi province, and a total of 458 responses were used for analysis. Factors with relatively low comparison degree were as follows. 'Handwashing and clean uniform of employee in the workplace', 'regular checking and managing of trapped vermin and rodents', 'checking stocked raw materials', 'recording and filing the results of improved food safety factors', and 'regular cleaning and sterilizing of monitoring tools' factors must be improved along with their performance levels through sanitation education. According to the IPA results, among the 15 HACCP prerequisite factors with high importance but low performance were '2. Regular checking and managing of trapped vermin and rodents', '4. Handwashing and clean uniform of employee in the workplace', '14. Preventing food cross-contamination'. Furthermore, the small and medium foodservice industry IPA with high importance but low performance were 'Regular checking and managing of trapped vermin and rodents', 'Handwashing and clean uniform of employee in the workplace', and 'Preventing food cross-contamination' for the small foodservice industry, along with 'Vermin and rodents control' and 'Recording and filing the results of improved food safety factors' for the medium foodservice industry. Thus, there is a need for reinforced hygiene education through case studies on actual food service establishments to fulfill sanitation guidelines and set amended guides for much-needed items for small and mid-sized food service.

• Korean Journal of Biological Psychiatry
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• v.6 no.1
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• pp.102-110
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• 1999

Objectives : The alcohol dependence in elderly people has been prevalent because of increase in geriatric population. However, it is difficult to find out alcohol dependence in the aged, because they have less specific clinical features as compared with adult alcoholics. The aims of this study were to screen alcohol dependence among elderly Koreans and to know the clinical characteristics of Korean delerly alcoholics. Methods : The questionnaires translated into Korean such as Michigan Alcoholism Screening Test(MAST-K), the Brief MAST and the MAST-Geriatirc Version (MAST-KG) were used to screen alcohol dependence in the elderly alcoholic inpatients aged over 60(N=43), adult alcoholic inpatients within 20-59 Yrs of age(N=60), which were compared with age matched normal healthy aged(N=18) or adult controls(N=45). The demographic data such as sex, age, education, occupation, socioeconomic status, marital status, numbers of children, dwelling and religion as well as alcohol history such as duration of alcohol drinking, onset age, family history, impulsivity, somatic illness and motivation were also obtained to identify characteristic features of Korean aged alcoholics by structured interviews. Results : 1) The aged alcoholics had the charateristic features of more in males, lower age, low education levels, more in blue-collar workers, lower socioeconomic class, more in single, few babies, more living alone, having no religion without statistical significance. 2) The onset age of alcohol dependence was significantly higher in the aged alcoholics($45.3{\pm}13.6Yrs$) than in the adult alcoholics($27.7{\pm}8.7Yrs$)(p<0.0001). The duration of problematic alcohol drinking was significantly longer in the aged alcoholics($22.0{\pm}15.1Yrs$) than in adult alcoholics($14.2{\pm}8.4Yrs$)(p<0.01). Otherwise, there were no significant difference between aged and adult alcoholics in the family history, imulsivity, somatic illness and motivation. 3) The mean score of the MAST-K was significantly higher in the aged alcoholics($20.6{\pm}5.4$) than in the normal aged($6.7{\pm}4.4$)(p<0.0001), which was significantly lower than in the adult alcoholics($26.2{\pm}8.0$) and in normal adult controls($9.5{\pm}3.2$)(p<0.05). The mean score of the Brief MAST was significantly lower in the aged alcoholics($9.3{\pm}3.5$) than in the adult alcoholics($14.5{\pm}6.6$)(p<0.0001). The mean score of the MAST-KG was significantly higher in the aged alcoholics($10.6{\pm}3.5$) than in the normal aged($4.8{\pm}4.3$)(p<0.0001). The former was significantly lower than in the adult alcoholics($12.9{\pm}4.3$)(p<0.005), and the mean score was $4.5{\pm}2.8$ in normal adult controls. 4) The items which showed statistically significant differences between aged alcoholics and normal aged controls could be found in 10 items of the MAST-K(items 2, 3, 4, 5, 11, 14, 17, 21, 22 and 23), 2 items of the Brief MAST(items 2 and 9), and 7 items of the MAST-KG(items 6, 13, 18, 19, 22, 23 and 24)(p<0.01). Conclusions : The scores of the MAST-K, the Brief MAST and the MAST-KG were significantly lower in the aged alcoholics than those in the adult alcoholics (p<0.05). The statistically significant differences between aged alcoholics and normal aged controls could be found in 10 items of the MAST-K, 2 items of the Brief MAST and 7 items of the MAST-KG. Therefore, a briefer rating scales around 10 items are needed to screen alcohol dependence among Korean elderly people.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.117-124
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• 2018

The imports of Centella asiatica L. Urban are increasing year-by-year due to the fact that its extract is a raw material used for skin wounds and in cosmetics. However, studies on the cultivation and identification of native C. asiatica species in Korea have been extremely rare. Therefore, this study was conducted in order to investigate the physiological and functional activity of Korean native C. asiatica plant cultivated in Hapcheon, Gyeongsangnam-do, Korea. As a result, the highest antibacterial and anti-inflammatory activities were examined with methanol extract while skin-whitening and wrinkle improvement were examined with water extract. Seven bacterium and one fungus were treated with 50% methanol extracts of C. asiatica and most of the bacterium showed similar or low levels of antibacterial activity compared to the control group of Omiza (Schisandra chinensis) extract, except for Streptococcus pyogenes, which showed higher antimicrobial activity than that of Omiza extract. However, neither C. asiatica and Omiza extracts showed antimicrobial activity against the fungus, C. albicans. The results of anti-inflammatory effect analyses with Raw 264.7 cells confirmed that the treatment of methanol extract reduced the level of NO by 50% or more compared to the control group. In addition, the water extract showed the highest reduction of melanin content of up to 20% more than the control group when examined with B16F10 cell line, indicating a significant skin-whitening effect. Furthermore, we were able to show the significant skin wrinkle improvement caused by C. asiatica extract with NHDF cell as an indicator, but strong cytotoxicity was also observed, suggesting that further studies are necessary.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.9-19
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• 1992

To ditermine the accumulation of Cu and Pb in crops grown on Sludge-treated Soils, four crop plants, green onion(A Ilium ascalonicum L.), radish(Raphanus sativus L.), potato(Solanum tuberosum L.) and Chinese cabbage(Brassica pekinensis Rupr), were grown in greenhouses on soils treated with municipal sewage sludge at different levels of 0, 22.5, 45, and 90ton/ha as soil dry weight. The contant of heavy metals were analyzed in plant parts of the crop species and the statistical characteristics were investigated. The results were as follows: 1. Cu and Pb contents in experimental plants were increased in accordance with quanti of sludge applied. 2. Accumulation of Cu and Pb in leaves of plants was increased in order of radish

• Korean Journal of Psychosomatic Medicine
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• v.7 no.2
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• pp.213-225
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• 1999

Objectives : The purpose of this study was to investigate how the play habits, temperament, and environmental factors might affect childhood obesity. Methods : Two hundred sixty children, aged 4 through 6 years living in Seoul & Cheonan were surveyed by a questionnaire about the children's play habit and the parent's related factors such as weight, height, education, income. In addition the Korean version of the Parent Temperament Questionnaire for Children and the Korean version of the Family Environment Scale were also administered to parents of those children. The height and weight of those children were measured and the percentage of body fat was measured by Bioelectrical Impedance Fatness Analyzer. Result : 1) Among 260 children, 25 children were considered to be obese on the basis of both obesity index and percentage of body fat. 2) Parents of obese children showed a significantly higher educational level(p<0.05) and mothers of obese children had significantly more jobs(p<0.05) and showed higher body mass index(p<0.05) than those of nonobese children. 3) By observing play habits of children, obese children spent significantly longer time in watching TV and video(p<0.05), while nonobese children showed a trend to play outside(p<0.1). 4) On the Korean version of the Parent Temperament Questionnaire for Children, obese children showed significantly less activity than nonobese ones(p <0.05). 5) Family of obese children had significantly higher point on subscale of Achievement orientation, Intellectual-cultural orientation and Moral-religious emphasis of the Korean version of the Family Environment Scale(p<0.05). 6) Percentage of body fat of obese children was correlated with children's watching TV time, activity level, scores of Achievement orientation, Intellectual-cultural orientation of the Korean version of the Family Environment Scale and the both parent's education levels(p<0.05). Conclusion : Obese children showed hypoactivity and more watching TV time. And obese children's both parent had higher educational level and their mother had higher Body Mass Index and more jobs. Family of obese children had higher point on items of Achievement orientation, Intellectual-cultural orientation and Moral-religious emphasis. Family environmental factors influence on children's obesity through interaction of genetic and behavioral-psychological factors concomittently.

• Journal of The Korean Association For Science Education
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• v.32 no.5
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• pp.903-927
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• 2012

The study aimed to analyze middle school students construction of physics inquiry problems for open inquiry from the viewpoint of variable isolation and clarification, and investigate students' difficulties during the processes of variable isolation and clarification to get implications for teaching and learning strategies for small group open inquiry activities which have been included in the 2007 national curriculum. The participants were 4 students who had attended an outreach program for the science gifted run by a university institution located in Seoul area. They performed an open inquiry on egg drop for 13 lessons for 30 hours. Level descriptions for variable isolation and clarification have been developed and applied to analyze students' inquiry problems and variables included by the problems. Students iterated inquiry processed 5 times and the inquiry problem showed progress gradually. Dependent variables have been isolated ahead and the levels of variable isolation and clarification showed higher than the independent variables. Many kinds of independent variables isolated extensively and the independent variables and control variables have been mingled. One of the reasons why students had some difficulties in isolation of independent variables could be the absence of theoretical models. The realities of school lab could restrict the variable isolation and clarification as well as topic selections. Some sensory or extensive variables such as broken eggs and drop height seem to be salient to be focused on as core variables. Lack of background knowledges could be one of the reasons for students' difficulties in variable clarification, such as theoretical definitions and operational definitions. As a result of lacking background knowledges, students could not construct theoretical models even though they could isolate and clarify variables as scientific lexical definitions. Some perceptions of inquiry as trial and error or reckless establishment of causal relations between variables could be accounted as one reason.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.518-525
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• 2010

The purpose of the study was to examine health-related behaviors and nutrient intake in relation to job stress level of police officers. Total of 166 police officers working in Jeonbuk area participated in the study. The study was conducted from February to March, 2009. Subjects were given self-administered questionnaire on their general health status, dietary and health-related habits. Nutrient intake was assessed by semi-quantitative food frequency questionnaire. Subjects were divided into four groups (very low, low, high, very high) by their job stress level scores. Main concerns of job stress were from 'job demand', 'organizational system' and 'lack of reward'. More than 95% of the subjects were confident of their health status. Health habits, such as drinking, smoking and exercising, were better than that of average Korean men. There were significant differences in dietary habits in relation to job stress level. Lower job stress group showed lower rate of skipping breakfast (p<0.01), more affordable meal time (p<0.05) and better snacking habits (p<0.001). Sweet food preference was higher in lower job stress group (p<0.05). The average calorie intake was $2063\pm532.7$ (88.5% of EER) and there was no significant difference in nutrient intake among job stress levels. However, mean intake of calcium and vitamin $B_2$ was less than 75% of %DRI in higher job stress group. Therefore, further support in nutritional counseling programs to improve dietary behaviors and health habits and to reduce job concerned stress of the police officers will be necessary.