• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.83-91
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• 2007

An experimental verification of multipactor(MP) discharge for S-band diplexer as a sample DUT for space application by an in-house MP test facility is proposed. The designed diplexer having two BPFs for Rx and Tx is applied to a design of five pole inter-digital cavity type band pass filter with chebyshev response, it has 2.7 % bandwidth centered at 2.232 and 2.055 GHz for Rx, Tx, respectively. To avoid the MP discharge, the accurate design and analysis methods based on 3D EM field analysis are considered. The proposed in-house MP test facility consists of a phase detecting system using a doubly balanced mixer as a simple, low cost and real time MP test method compared with results of previously well-known MP detection systems as cross reference methods. The calculated MP threshold RF input power is 43.13 dBm. The measured one is 43 dBm and 44 dBm for CW, pulsed mode test, respectively.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.471-479
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• 2017

White spot syndrome virus (WSSV) is a major threat to the shrimp farming industry and so far there is no effective therapy for it, and thus early diagnostic of WSSV is of great importance. However, at the early stage of infection, the extremely low-abundance of WSSV DNA challenges the detection sensitivity and accuracy of PCR. To effectively detect low-abundance WSSV, here we developed a pre-amplification PCR (pre-amp PCR) method to amplify trace amounts of WSSV DNA from massive background genomic DNA. Combining with normal specific PCR, 10 copies of target WSSV genes were detected from ${\sim}10^{10}$ magnitude of backgrounds. In particular, multiple target genes were able to be balanced amplified with similar efficiency due to the usage of the universal primer. The efficiency of the pre-amp PCR was validated by nested-PCR and quantitative PCR, and pre-amp PCR showed higher efficiency than nested-PCR when multiple targets were detected. The developed method is particularly suitable for the super early diagnosis of WSSV, and has potential to be applied in other low-abundance sample detection cases.

• Nutrition Research and Practice
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• v.7 no.2
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• pp.139-145
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• 2013

There is a lack of data on metabolic risk factors during pre-puberty, which is important for identifying the subgroups of youth, at whom early interventions should be targeted. In this study, we evaluated the prevalence of metabolic risk factors and its subsequent relations with dietary patterns in Korean pre-pubertal children through a cross-sectional sample (n = 1,008; boys = 513) of pre-pubertal children (aged 8-9 years) from a sub-study of the Korea Metabolic Syndrome Research Initiatives (KMSRI) in Seoul, Korea. Measures of anthropometry and blood pressure as well as fasting blood samples were used in the analysis. A three-day food records were collected. The metabolic syndrome was defined according to the age-adjusted National Cholesterol Education Program Adult Treatment Panel III guidelines. An added metabolic risk score was calculated for each subject by summing the quintile values of the five individual risk factors. Among the 5 risk components of metabolic syndrome, high waist circumference (WC) was the major factor (P < 0.001). A significant increasing trend of the added metabolic syndrome risk score was observed with the increase of WC (P (trend) < 0.001) among both genders. The cutoff point for high WC for pre-pubertal children was 61.3 cm for boys and 59.9 cm for girls. The prevalence of high triglyceride (TG) values was significantly higher in girls than it was in boys (P < 0.01). Girls in the highest quintile of balanced dietary pattern scores had lower TG values (P (trend) = 0.032) than did those in the lowest quintile. Moreover, girls in the highest quintile of western dietary pattern scores showed increasing trend for the added metabolic risk score (P (trend) = 0.026) compared with those in the lowest quintile. Adverse associations exist between western dietary patterns and the accumulation of metabolic risks among girls, not in boys, even during pre-puberty.

• Journal of KIISE:Software and Applications
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• v.34 no.9
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• pp.804-816
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• 2007

Sample training data for machine learning often contain irrelevant information or redundant concept. It is also the case that the original data may include noise. If the information collected for constructing learning model is not reliable, it is difficult to obtain accurate information. So the system attempts to find relations or regulations between features and categories in the teaming phase. The feature selection is to remove irrelevant or redundant information before constructing teaming model. for improving its performance. Existing feature selection methods assume that the distribution of documents is balanced in terms of the number of documents for each class and the length of each document. In practice, however, it is difficult not only to prepare a set of documents with almost equal length, but also to define a number of classes with fixed number of document elements. In this paper, we propose a new feature selection method that considers the impurities among the words and unbalanced distribution of documents in categories. We could obtain feature candidates using the word impurity and eventually select the features through unbalanced distribution of documents. We demonstrate that our method performs better than other existing methods via some experiments.

• Journal of Ginseng Research
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• v.31 no.1
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• pp.34-43
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• 2007

Background: Previous research has suggested that single doses of a standardised Panax ginseng extract can decrease fasted blood-glucose levels and modulate cognitive performance in healthy young volunteers. The latter has generally been seen in terms of improved secondary memory performance. However, both the cognitive effects of chronic administration of ginseng and the potential modulation of working memory have received comparatively little research attention. Aims: The current double-blind, placebo-controlled, balanced cross-over study investigated the effects of 8-weeks administration of Korean ginseng extract (200 mg) on cognitive performance, gluco-regulatory parameters and ratings of subjective mood and 'quality of life'. Methods: 'Eighteen healthy young participants were assessed pre-dose and 3 hours post-dose on the mornings of Day 1, Day 29 and Day 57 of 8 week treatment regimens of both placebo and ginseng. A four-week placebo wash-out separated the treatment phases. Each assessment included the Cognitive Drug Research battery, computerised working memory tasks, and Bond-Lader mood scales. The WHO Quality of Life scale (WHOQOL-BREF) was completed once per visit. Gluco-regulatory parameters were assessed with assays of blood glucose, insulin and HbA1c. Results: Data from the 16 participants that completed the study showed that there were no significant, acute treatment related differences on Day 1 of treatment, or in gluco-regulatory parameters throughout the study. However, time related performance improvements were evident following chronic administration of ginseng on the '3-Back' and 'Corsi-block' computerised working memory tasks. Ginseng was also associated with an improved score on the 'social relations' subscale of the WHOQOL-100, and a significant shift on the 'calm' factor of the Bond-Lader mood scales (from calm/relaxed towards excited/tense). Conclusion: The results of the current study suggest that Korean ginseng extract can modulate working memory performance and subjective ratings of 'quality of life' and mood. Replication with a larger sample size may further elucidate the actions of this product.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.156-162
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• 2012

The purpose of this study was to investigate the effect and correlation of anthropometric data, eating behaviors, and nutrient intake on the bone mineral density(BMD) of female college students. 349 female college students were surveyed and their age, height, and weight were an average of 20.5 years, 163.2 cm and 54.0 kg, respectively. Their average BMI was 20.2, with 66% falling in the normal range, 21.8% classified as underweight, 8.0% as overweight, and obese individuals comprised 3.4% of the sample by BMI classification. Calcaneal BMD was measured and the average T-score was 0.117. The results of BMD measurements were normal in 268 people(76.8%), osteopenia was found in 71 individuals(20.3%), and osteoporosis in 10(2.9%), respectively. There was a significant difference in bone mineral density according to height(p<0.05) and BMI (p<0.01). There were significant differences between BMD and eating behavior, regularity of eating behaviors(p<0.05), instant food intake(p<0.05), eating out(p<0.05) and nutritional supplement intake(p<0.05). In addition, normal the group with normal BMD had a more desirable eating behavior compared to the osteopenia and osteoporosis afflicted groups. BMD had a significant difference according to the nutrient intake of calcium(p<0.05), vitamin A(p<0.05), and vitamin C(p<0.05). In conclusion, BMD showed a good correlation with height(p<0.01), BMI(p<0.01), body composition including total body water(p<0.05), FFM(p<0.05), body protein(p<0.05) and intake of calcium(p<0.05), iron(p<0.05), vitamin A(p<0.05), and vitamin C(p<0.05). Therefore, an education plan and training on balanced diets proper body weight control, and desirable eating behaviors for female college students will be needed.

• Korean Journal of Community Nutrition
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• v.22 no.2
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• pp.145-158
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• 2017

Objectives: The importance of kimchi as a traditional food in Korean cuisine has gradually decreased due to rapid industrialization, economic growth and changes in dietary patterns in Korea. This study aimed to examine the shifts in kimchi consumption by region and by income level between 2005 and 2015 in Korea. Methods: Data from the Korea National Health and Nutrition Examination Surveys III (2005) and VI (2015) were used in the study (n=15,558). Intake of kimchi was estimated using a single 24-hour dietary recall. The sample weights were applied in all analyses to reflect population estimates. All statistical analyses were carried out by using SPSS IBM Statistics 20. Results: Kimchi intake has significantly decreased by 27.6 g/day per capita during the last decade in Korea; 25.0 g for males and 29.9 g for females, respectively. Over the past decade, the decline of kimchi intake has been particularly significant in Seoul, Busan, Incheon, Gyeonggi, and Gwangju, while there has been no significant change in males living in rural areas. The consumption of kimchi across all income levels has decreased, however, the decrease was higher in 'middle and low income level'. The amount of kimchi consumption in 2015 was the highest in 'low income level'. The results were similar after adjusting for gender and age. Conclusions: For the past decade, the overall intake of kimchi in Korea has decreased, however, it has been found that the decrease of kimchi intake for males living in the rural areas was not significant. Therefore, in order to keep our traditional kimchi culture and promote a balanced diet including kimchi for Korean, it is necessary to develop more efficient policies and approaches. A variety of dishes using kimchi should be developed, besides merely serving kimchi with rice as a side dish, to increase the consumption of kimchi.

• Journal of the Korean Dietetic Association
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• v.8 no.3
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• pp.260-268
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• 2002

The purpose of this study was to compare food behaviors, nutrient intake, clinical symptoms, and hematological findings by smoking status. Among the third grade male students from a high school in Jinchun-kun, 31 smokers and 31 nonsmokers participated in this study. A self-administered questionnaire was used to investigate food behaviors and clinical symptoms. Nutrient intake data were collected by 24-hour recall method. Blood sample was drawn from each subject to determine the levels of hemoglobin, protein, triglyceride, cholesterol, etc. The major findings were as follows; First, smokers consumed every food group except fat & oil less frequently than nonsmokers, while they consumed instant food, coffee, alcoholic beverages more frequently than nonsmokers. Dietary habits of smokers such as regularity, balanced diet, skipping meals were worse than those of non-smokers. Second, intakes of energy, fat, carbohydrate, and β-carotene of smokers were lower than those of non-smokers. Third, smokers felt fatigue and other adverse symptoms more often than non-smokers. Fourth, the levels of hemoglobin, albumin and HDL-cholesterol were significantly lower in smokers than non-smokers. Fifth, Smoking history was negatively correlated with food behaviors, energy intake and clinical symptoms. These results suggest that food behaviors, nutrient intakes, hematological findings and clinical symptoms of male high school students were affected by smoking. Therefore, in order to decrease smoking rate of the students, the effect of smoking on nutritional and health status should be informed and nutrition education should be offered to the students.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.6
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• pp.965-973
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• 2008

In this study, we compared the quality and sensory characteristics of 4 types of fresh tomatoes and 2 types of canned tomatoes, and then determined the most preferred quality characteristics and tomato type for the production of tomato sauce. The sample tomatoes were prepared by cutting after either peeling or heating for 5 min. Soluble solids were in the following order: Italian canned >American canned, Cherry> Vita king > Aranka > general tomatoes. The primary free sugars were fructose and glucose, and we determined that fructose and glucose were the most prevalent sugars in the cherry and American canned tomatoes. The total sugars, which were the sum of the fructose and glucose contents, were consistent with the soluble solid contents. pH was measured in the following order: general> Italian canned> Cherry, Vitaking> Aranka> American canned tomatoes. The most abundant amino acid was glutamic acid, and its content in the unheated tomatoes occurred in the following order: American canned> Italian canned> Vita king> Cherry> general tomatoes; however, after heating, the Vita king tomato was followed by the American canned tomato. The lightness (L value) of the fresh tomatoes tended to be higher than that of the canned tomatoes, and it decreased after heating. The redness (a value) of the unheated tomatoes was in the following order: Italian canned> American canned> Vitaking tomatoes; after heating, the Vitaking evidenced the highest values, followed by the canned tomatoes. The result of our QDA profile of sensory characteristics according to redness, aroma, sweet taste, sour taste, palatability, and viscosity was in the following order: Italian canned > American canned > Vitaking tomatoes, which evidenced the most balanced hexagonal shape. In the preference test, 2 types of canned tomatoes and Vitaking tomatoes were the most preferred among the fresh tomatoes. From the correlation coefficients among the sensory characteristics, canned tomatoes were the most preferred for the production of tomato sauce due to its high redness, flavor, palatability, and viscosity values. Vitaking tomatoes were the most appropriate among the fresh tomatoes.

• The Journal of the Korea Contents Association
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• v.19 no.12
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• pp.647-659
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• 2019

The purpose of this study was to investigate the influence of children's elementary school entrance to working conditions of employed mothers. The data from 4th to 8th wave of Panel Study on Korean Children (PSKC) were used for analysis. Specifically, we examined changes in wages, working hours and regular employment of employed mothers after their children entered elementary schools. We adopted Heck selection model for unbalanced panel data after controlling sample selection bias, and compare results of analysis for unbalanced and balanced panel data. The results showed that children's elementary school entrance reduces employed mothers' wage, working hours and regular employment. These results indicate that mother tend to leave regular job and could not entry into decent job when their children are in elementary school.