• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.285-292
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• 2019

Our study was based on the long-term surveys with respect to the major reservoirs located in the Yeongsan and Seomjin river basins. A total of 45 survey sites have been surveyed four times a year from 2008 to 2017. We identified 166 zooplankton species, including 127 rotifers, 26 cladocerans, and 13 copepods. Mean population density and species number of small reservoirs were higher than those of mid and large reservoirs. Considering outliers exceeding the 90th percentile between species occupancy and mean abundance, 10 of 11 habitat generalists were rotifers, and Bosmina longirostris was the only cladoceran. Habitat specialist consisted of three species of rotifers and emerged from one to three survey sites. According to the modularity results, it was found that the survey sites covering the entire river basins were characterized into five groups, which was similar to the classification by maximum water surface areas(MWSA). The result of the eigenvector centrality showed that the size of MWSA had a greater impact on the similarity of zooplankton community structure between reservoirs than the difference in distance between reservoirs. In the case of survey points in near dam or estuary bank of Juam and Youngsan reservoirs, modularity class were separated from other internal survey points of those. Given that the zooplankton interactions may contribute to freshwater functions more than species diversity. These topological features provide new insight into studying zooplankton distribution patterns, their organization and impacts on freshwater-associated function.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.4
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• pp.334-345
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• 2006

The objectives of this study were to analyze and compare 24 hrs personal exposure levels of MF at microenvironments such as home, school, educational institute, internet pc game room, transportation, and other places according to time activity patterns using various metrics for children attending the primary schools located near and away from the power lines, and to characterize the major microenvironments and impact factors attributed personal exposure level. The study was carried out for 44 children attending a primary school away from the lines(school A) and 125 children attending a school away from 154 kV power lines(school B), all who aged 12 years and were 6 grade, from July 2003 to December 2003. All participants filled in a questionnaire about characteristics, residence, use of electrical appliances and others. Children wore a small satchel in which EMDEX II and Lite (Enertech, Co. Ltd) and a diary of activity list for period of registration in 20 minutes blocks. All statistical calculations were made with the SAS System, Releas 6.12. The summary of results was presented below. First, about the characteristics of subjects, there no differences between two groups. The subject almost spent about 56 % of their time at home and about 20~25 % of their time at school. Fifty percent of children spent 2 hours at private educational institutes. Second, the personal exposure measurements of children in school B was statistically higher than those of children in school A by various metrics such as arithmetic mean, geometric mean, percentile(5, 25, 50, 75, 95), maximum, rate of change metric, constant field metric. The arithmetic and geometric mean magnetic fields during the time the children were at school B were 0.98 and $0.86{\mu}T$ and were about 23 times higher than those of children were at school A. In conclusion, the significant major determinants of personal exposure level is the distance from the power line to microenvironments.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.547-554
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• 2010

Purpose: The purpose of this study is to delineate the optimal time of venous revascularization for preventing the flap necrosis due to venous occlusion, and to clarify the usefulness of tissue oxygen pressure ($TcpO_2$) in the determination of the point of time for venous revascularization. Methods: Thirty-six, $3{\times}3\;cm$ sized epigastric island flap was elevated in left abdomen of male Sprague-Dawley rat weighing 250 gram. Flaps were randomly assigned to six groups of six flaps according to the duration of venous occlusion with microvascular clamp; 10 minutes in the group I as the control, 60 minutes in the group II, 2 hours in the group III, 3 hours in the group IV, 4 hours in the group V, and 6 hours in the group VI, respectively. Just before removal of clamp after flap was reposed in situ, the ratio of $TcpO_2$ (tissue oxygen pressure) of the island flap to that of right abdomen was calculated in each group, and tissue specimen was harvested from the distal area of the flap for histological evaluation of vascular change. Five days later, survival area of the flap was estimated, and evaluated the correlation between the tissue oxygen pressure and the rate of flap survival. Results: The $TcpO_2$ and the survival rate of flap were decreased proportionally with the duration of venous occlusion. The ratio of the $TcpO_2$ of the flap is decreased abruptly to below sixty percentile compared to the $TcpO_2$ of normal tissue, and the survived area of the flap is decreased to nine-tenth of the designed size after three hours of total venous occlusion. Histologically, the number of congested vessels was increased according to venous occluded time, and proportionally increased after 3-hours of occlusion significantly. Conclusion: There is a close correlation between the $TcpO_2$ and the survival rate of flaps according to the duration of venous occlusion. Therefore, the $TcpO_2$ represents the hemodynamic changes within the flap, and thought to be an alternative effective tool in the flap monitoring for venous revascularization.

• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.57-63
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• 2011

This survey was conducted to develop an appropriate management for safety of children snacks. In this study, monitorings of food additives such as nine kinds of tar colors (tartrazine, sunset yellow FCF, brilliant blue FCF, indigo carmine, new coccine, amaranth, erythrosine, allura red and fast green FCF) which are sold at stationary store around the school, were performed. Eighty two samples (3 snacks, 71 candies, 4 chocolates and 4 beverages) were analyzed for tar colors. Results of risk assessment for tar colors were expressed as EDI (Estimated Daily Intake) comparing with ADI (Acceptable Daily Intake). The ratio of high risk group for tar color intake (95th) were 0-3.56%. The consumptions of tar colors from domestic and imported products for nine kinds of tar colors in candies were not significantly different. The results of this study indicated that each ED! of nine kinds of tar colors sold at stationary store around the school is much lower than each ADI in general. Consequently, the children snacks are thought to be safe for consumption.

• Korean Journal of Health Education and Promotion
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• v.15 no.2
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• pp.81-93
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• 1998

The purpose of this study was to analyze the results of teachers' self-evaluation on their health teaching behaviors, then to furnish the basic data to be able to improve teachers' health teaching activities and the educational issues on the education of teachers. To put above aims into practice, these were required: 1. Are there any differences in the results of self-evaluation on health teaching behaviors factors by teachers? 2. Are there any differences in the results of health teaching self-evaluation whether he/she take P.E as major of study in-serviece training period? 3. Does it have any influence on the results of health teaching self-evaluation whether he or she completed on the job training for the school health? 4. Are there any differences in the results of health teaching self-evaluation by sex and career? To carry out a research for this purpose, the factors of health teaching self-evaluation were divided into the clearness of the procedure, the active interaction, the variety of the ways showing the contents, and the individualization of the procedure. Then a questionnaire form, consisting of 28 specific inquires to evaluate health teaching behaviors, was delivered and conducted by 450 teacher of the elementary school in Kyungki-do. The analysis of data was done by SPSS; producing mean and standard deviation and they were inspected statistically to compare the evaluation levels and find out the differences by teachers' personal variables. The conclusion were as follows: 1. In the self-evaluation level of teachers' health teaching behaviors, teachers showed 68.23 point as are percentile distribution. And it was in order of a school-nurse(71.68), an athletic teacher(67.29), and a class-room teacher (65.66). Score obtained by teacher was statistically significant difference (p〈.001) 2. In the factors affecting to teachers' health instruction, “active interaction” showed the highest score(18.55), “variety of ways showing the contents”(17.38), “clearness of the procedure” (16.70), and “individualization of the procedure” (15.59). In the analysis of the differences by teachers, according to factors, there were significant differences in “active interaction”, “variety of the ways showing contents”, “clearness of the procedure”(p〈.001). 3. Self-evaluation score for graduates from Dept. of P. E in Teachers' collage was not significant difference compared with other majors(p〉.05). 4. Teachers receiving health education was significantly higher self-evaluation score than that of teachers not-receiving health education (P〈.01). 5. Self-evaluation score of female teacher was significant difference compared with that of male teacher (p〈.001). 6. Career (working duration) did not influenced to self-evaluation score on health teaching behaviors (P〉 .05). On the basis of the conclusion of this study, the next are suggested: First, the further studies to make use of the results of health teaching behaviors and to examine the effect are needed. Second, the further studies to examine the relations between academic achievement and teachers' major(a school-nurse, an athletic teacher, and a class-room teacher) are needed. Third, the following studies to improve health teaching by both teachers' self-evaluation on health teaching behaviors and students' evaluation of teachers, and to find out more effective health teaching, are needed. Fourth, Health education for pre-service training course and On-the-Job training program are need the effective factors on the teachers' Health teaching obtained from this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.1
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• pp.31-36
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• 1983

This experiment was carried out to evaluate the sanitary quality of ground water in Pusan area(see Fig. 1). One hundred and thirty two water samples were collected from the 11 stations from October 1981 to Sept ember 1982. To evaluate the sanitary quality, coliform group, fecal coliform, viable cell count and composition of coliform group by IMViC reaction were observed. The median value of coliform group MPN of the samples were 59/100 ml in Udong and Daesindong, 68/100 ml in Suyeong, Yeonsandong and Sungjigog, 43/100 ml in Jenpodong and Mangmidong, 33/100 ml in Yeongdo and Dongrae, and 13.3/100 ml in Gammandong. Geometric mean of fecal coliform MPM was 4.1/100ml in Udong, 8.6/100 ml in Suyeong, 8.1/100 ml in Jenpodong, 6.1/100 ml in Daesindong and Dongrae, 8.7/100 ml in Yeongdo, 7.1/100 ml in Mangmidong, 6.5/100 ml in Yeonsandong, 9.1/100 ml in Sungjigog, 3.0/100 ml in Gammandong and 7.6/100 ml in Gupo. The seasonal difference of total coliform showed much more contamination in June or July when there were more climers than in December though it was caused by the rise of loafer temperature. With 50 percentile of total coliform MPN July was about 30 times higher than December for July was 163.5/100 ml and December 5.3/100 ml, Particularly, June was about 1.3 times higher than July in contamination because of a sudden increase of people using it. Composition of coliform was $7.64\%$ Escherichia coli, group, $42.86\%$ Citrobacter freundii group, $16.78\%$ Klebsiella aerogenes group and $32.72\%$ others. Plate count of samples was varied from 48 to $4.4{\times10}^2/ml$ during the study period.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.491-501
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• 2018

Objectives: The aims of this study were to compare concentrations and the correspondence of human blood cadmium by using graphite furnace atomic absorption spectrometry (GF-AAS) and inductively coupled plasma-mass spectrometry (ICP-MS), which are representative methods of heavy metal analysis. Methods: We randomly selected 79 people who agreed to participate in the research project. After confirming the linearity of the calibration curves for GF-AAS and ICP-MS, the concentrations of cadmium in a quality control standard material and blood samples were measured, and the correlation and the degree of agreement were compared. Results: The detection limit of ICP-MS (IDL: $0.000{\mu}g/L$, MDL: $0.06{\mu}g/L$) was lower than that of GF-AAS (IDL: $0.085{\mu}g/L$, MDL: $0.327{\mu}g/L$). The coefficient of variation of the quality control standard material showed stable values for both ICP-MS (clinchek-1: 5.35%, clinchek-2: 6.22%) and GF-AAS (clinchek-1: 7.92%, clinchek-2: 5.22%). Recovery was relatively high for both ICP-MS (clinchek-1: 95.1%, clinchek-2: 92.8%) and GF-AAS (clinchek-1: 91.4%, clinchek-2: 98.8%), with more than 90%. The geometric mean, median, and percentile of blood samples were all similar. The agreement of the two instruments compared with the bias of the analytical values found that about 81% of the analytical values were within ${\pm}30%$ of the deviation from the ideal reference line (y=0). As a result of the agreement limit, the value included in the confidence interval was about 94%, which shows high agreement. Conclusion: In this study, we confirmed there was no significant difference in concentrations of a quality control standard material and blood samples. Since ICP-MS showed lower concentrations than GF-AAS at concentrations below the method detection limit of GF-AAS, it is expected that more precise results will be obtained by analyzing blood cadmium with ICP-MS.

• Nutrition Research and Practice
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• v.10 no.2
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• pp.198-205
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• 2016

BACKGROUND/OBJECTIVES: A healthy diet has been reported to be associated with physical development, cognition and academic performance, and personality during adolescence. This study was performed to investigate the relationships among milk consumption and academic performance, learning motivation and strategies, and personality among Korean adolescents. SUBJECTS/METHODS: The study was divided into two parts. The first part was a survey on the relationship between milk consumption and academic performance, in which intakes of milk and milk products and academic scores were examined in percentiles among 630 middle and high school students residing in small and medium-sized cities in 2009. The second part was a survey on the relationships between milk consumption and learning motivation and strategy as well as personality, in which milk consumption habits were collected and Learning Motivation and Strategy Test (L-MOST) for adolescents and Total Personality Inventory for Adolescents (TPI-A) were conducted in 262 high school students in 2011. RESULTS: In the 2009 survey, milk and milk product intakes of subjects were divided into a low intake group (LM: ${\leq}60.2g/day$), medium intake group (MM: 60.3-150.9 g/day), and high intake group (HM: ${\geq}151.0g/day$). Academic performance of each group was expressed as a percentile, and performance in Korean, social science, and mathematics was significantly higher in the HM group (P < 0.05). In the 2011 survey, the group with a higher frequency of everyday milk consumption showed significantly higher "learning strategy total," "testing technique," and "resources management technique" scores (P < 0.05) in all subjects. However, when subjects were divided by gender, milk intake frequency, learning strategy total, class participation technique, and testing technique showed significantly positive correlations (P < 0.05) in boys, whereas no correlation was observed in girls. Correlations between milk intake frequency and each item of the personality test were only detected in boys, and milk intake frequency showed positive correlations with "total agreeability", "organization", "responsibility", "conscientiousness", and "intellectual curiosity" (P < 0.05). CONCLUSION: Intakes of milk and milk products were correlated with academic performance (Korean, social science, and mathematics) in Korean adolescents. In male high school students, particularly, higher milk intake frequency was positively correlated with learning motivation and strategy as well as some items of the personality inventory.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.617-629
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• 2020

In order to overcome the limitations of the rule-based intrusion detection system due to changes in Internet computing environments, the emergence of new services, and creativity of attackers, network anomaly detection (NAD) using machine learning and deep learning technologies has received much attention. Most of these existing machine learning and deep learning technologies for NAD use supervised learning methods to learn a set of training data set labeled 'normal' and 'attack'. This paper presents the feasibility of the unsupervised learning AutoEncoder(AE) to NAD from data sets collecting of secured network traffic without labeled responses. To verify the performance of the proposed AE mode, we present the experimental results in terms of accuracy, precision, recall, f1-score, and ROC AUC value on the NSL-KDD training and test data sets. In particular, we model a reference AE through the deep analysis of diverse AEs varying hyper-parameters such as the number of layers as well as considering the regularization and denoising effects. The reference model shows the f1-scores 90.4% and 89% of binary classification on the KDDTest+ and KDDTest-21 test data sets based on the threshold of the 82-th percentile of the AE reconstruction error of the training data set.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.13-20
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• 2005

Purpose : Obesity is, along with metabolic syndrome, closely related with nonalcoholic fatty liver disease. This study tried to evaluate the prevalence of nonalcoholic liver disease in obese children and verify the factors associated with the disease. Methods : Two hundred and seventy nine children who showed a body mass index of 95 percentile over the baseline in health examinations of surrounding schools were evaluated. Questionnaires, body measurements, blood examinations, and ultrasonographic measurements of abdominal fat were examined. Results : Out of 279 children enrolled for the study, 27 children were found to possess nonalcoholic liver disease(9.7%). Among those found to be positive for nonalcoholic liver disease, it's prevalence increased to 15.2%(22 out of 144 children) among children with severe obesity. Factors known to be involved with metabolic syndrome, namely waist/hip circumference ratio and thickness of abdominal fat, were found to be closely related to nonalcoholic fatty liver as well. Conclusion : The prevalence of nonalcoholic fatty liver in obese children was 9.7%, with higher incidence observable in severer obesity. Factors responsible for metabolic syndrome were closely associated with nonalcoholic fatty liver disease, and the level of insulin resistance, which is an useful index in both diseases, can be utilized in evaluation of the effect of treatment and control of risk factors.