• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.151-160
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• 1986

The authors studied depression using Zung's Self-Rating Depression Scale(SDS), in the subjects of 3,499 male and 1,335 female college freshmen of Yeungnam University. The authors collected the reports of SDS during the periods from January to February, 1986, and applied ANOVA and t-test on depression scores in order to compare them between various psychosocial factors, and sexes. The results are as follows : There was significant difference in the mean averages of total depression scores between male and female students: male students scored 35.68+7.46, female students scored 38.93+7.26(P<0.001). The depression scores relating to the items of indecisiveness, psychomotor retardation, decreased libido, and diurnal variation were relatively higher in both groups. One hundred and sixty-one male students(4.6%) showed seriously high degree depression scores of 50 or higher, while one-hundred and seventeen female students(5.8%) showed the same scores. Female students attending in liberal arts showed higher level of depression scores(P<0.01). There was a strong tendency toward higher depression scores in the student who were dissatisfied with their home atmosphere, colleges, department and familiarity of parents, and those who had pessimistic views of self image in the past, present or future in both groups(P<0.001).

• Clinical and Experimental Reproductive Medicine
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• v.36 no.1
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• pp.71-80
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• 2009

Objective: PCOS is one of the most common endocrine disorder affecting reproductive age women. It shows wide range of reproductive and metabolic manifestations. This study was to determine the differences of clinical and laboratory characteristics between adolescent and adult Korean Daegu Kyungpook PCOS patients. We also compared clinical and laboratory values of Korean PCOS patients to Turkish and American PCOS patients. Methods: 88 cases were diagnosed and enrolled as PCOS patients, based on 2003 Rotterdam criteria, who visited KNUH Reproductive Endocrinology division between Jan. 2000 and Apr. 2008. We retrospectively reviewed clinical characteristics, serum hormone levels, ultrasono-graphic findings. And we divided into 2 groups, adolescent and adult. We analyzed them with Chi-square test and Student's t-test statistically. Results: There were no statistically significant differences between adult and adolescent Korean PCOS patients. The prevalence of hyperandrogenism such as facial acne or hirsutism, obesity, and insulin resistance of Korean PCOS women was significantly lower than Turkish and American PCOS women. Conclusion: From the results of this study, we can suggest that it is sure that there are differences of clinical and laboratory characteristics of PCOS patients between races. Genetic background, dietary habits and life style affect the expression of clinical symptoms of PCOS. But we could not find out the difference between adolescent and adult PCOS patients of same race. It might be due to the limitation of small patient number and narrow range of age distribution. So, there must be large scale and multi-center and multi-regional study.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.295-304
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• 2013

This study aims to examine the level of fear and the influential factors affecting their dental fear and to utilize the result as the basic materials in the dental management. The subjects were the students from a middle school located in Cheongju-City. The school was selected by convenient sampling and self-answered questionnaire was filled in by the students for a week from December 19th 2011. The survey result showed that 77 male students and 169 female students(total 246 students) answered 'yes' to the question 'Have you ever felt fear when you visited a dentist?' among 475 students who had visited a dentist in the past. The distribution of responses in each category of fear was examined by frequency analysis. The study results showed significant difference in the item of 'causing irritation during the dental treatments' between male students and female students (p<0.05). Converting the level of fear into scores after marking the answers, the score of male students was 52.0 points and the score of female students was 58.53 showing the score of female students was significantly higher in statistics. Moreover, the fear score of female students for the category 'causing irritation during the dental treatments' was also significantly higher in statistics(p<0.05). Therefore, these results should be reflected to the dental care environments in order for the adolescent to reduce the dental anxiety and fear.

• The Journal of Korean Physical Therapy
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• v.12 no.1
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• pp.1-7
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• 2000

The purpose of this study was to determine the effect of microamperage electrical stimulation on the number of argyrophilic nucleolar organizer region (AgNOR) in rat skin. Twenty four male Sprague-Dawley rats were divided into electrical stimulation and control group. Bach animals hair on the back was removed. The electrical stimulation group received an positive rectangular positive electrical stimulation with $500{\mu}A$, while the control group was given the same treatment without electricity. The rats were sacrificed at 4 and 7 day of stimulation, respectively. The biopsy specimens were fixed in formalin, embedded in paraffin and stained with silver nitrate. The AgNOR were counted using a light microscope and computerized image analysis system and calculated as the mean number of AgNOR per nucleus in the epidermal keratinocyte. In control skin, the mean AgNOR count of epidermal keratinocyte at 4 and 7 day were 1.67 and 1.72, whereas electrical stimulated rat had mean AgNOR counts of 2.0 and 2.14, respectively. A Student's t-test showed a significantly higher mean AgNOR number at 4 ana 7 day in the electrical stimulated rats than control rats (p<0.05). The microamperage electric current stimulation increased the epidermal AgMOR expression in incisional wound skin. These results suggest that the microamperage electrical stimulation may promote migration and proliferative activity of epidermal keratinocyte in surgical wound.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.93-104
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• 2019

This study examined the relationship between the number of medical technologists and the medical test count. Data was obtained from 441 medical technologists in a hospital through a self-reported questionnaire. The Pearson correlation test, student's t-test, ANOVA or descriptive statistics were performed for data analysis. The distribution of medical technologist according to the size of hospitals was small 5.8, medium 14.9, large 25.8, and super 45.4. The analysis demonstrated a relationship between the number of medical technologists and the number of medical tests in the field, number of clinical tests per MT, and number of optimal medical test per MT according to the hospital size (P<0.001). The average time for quality control by the department at a higher hospital was less than two hours. In terms of the satisfaction of salary, work environment, test accomplishment, and welfare service, the dissatisfaction of medical technologists in small and medium hospitals was higher than those in large and super hospitals. Overall, a focus on intensifying systemic supplementation and improving the condition of medical technologists is needed to provide reliable data for medical examinations in medical areas.

• Journal of Digital Convergence
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• v.18 no.12
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• pp.425-434
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• 2020

Background: Viral infection outbreaks are emerging public health concerns. They often exhibit seasonal patterns that could be predicted by the application of big data and bioinformatic analyses. Purpose: The purpose of this study was to identify trends in diarrhea-causing viruses such as rotavirus (Gr.A), norovirus G-I, and norovirus G-II in Cheonan, Korea. The identified related factors of diarrhea-causing viruses may be used to predict their trend and prevent their infections. Method: A retrospective analysis of 4,009 fecal samples from June 2010 to December 2019 was carried out at Dankook University Hospital in Cheonan. Reverse transcription-PCR (RT-PCR) was employed to identify virus strains. Information about seasonal patterns of infection was extracted and compared with local weather data. Results: Out of the 4,009 fecal samples tested using multiplex RT-PCR (mRT-PCR), 985 were positive for infection with Gr.A, G-I, and G-II. Out of these 985 cases, 95.3% (n = 939) were under 10 years of age. Gr.A, G-I, and G-II showed high infection rates in patients under 10 years of age. Student's t-test showed a significant correlation between the detection rate of Gr.A and the relative humidity. The detection rate of G-II significantly correlated with wind-chill temperature. Conclusion: Climate factors differentially modulate rotavirus and norovirus infection patterns. These observations provide novel insights into the seasonal impact on the pathogenesis of Gr.A, G-I, and G-II.

• Journal of Nutrition and Health
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• v.56 no.3
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• pp.277-287
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• 2023

Purpose: This study was conducted to investigate the eating behavior (EB) and nutritional status of university students in Gwangju, and to compare their nutrition quotients (NQs) and problems according to their EB types. Methods: The subjects were 219 (127 female and 92 male) undergraduate students from Gwangju. The Student's t-test was used to compare the EB levels according to gender, and Pearson's χ² test was used to compare the distribution of EB types by gender. A gender-adjusted analysis of covariance (ANCOVA) was conducted to examine the difference in NQs by EB types. Results: First, there were significant differences in the EB scores and the distribution of EB types according to gender. Female students showed higher levels of emotional (Emo) and external (Ext) EBs than the male students, and Emo, Ext, and combined (Com) EB types were more evident among female rather than male students. Second, there was a difference in NQs according to the EB types. The Emo EB type subjects had a lower NQ than those of the restrained (Res) EB type and showed significant differences in diversity and dietary behavior. Specifically, the Emo EB type subjects displayed significantly lower efforts to maintain a healthy diet and subjective health status than the Com EB type and their levels of checking nutrition labels, hand washing, and water intake were significantly lower than that of the Res EB type. The Ext EB type showed significantly lower moderation of Ramyeon and sweetened drink intake than the Res and Com EB types. Conclusion: The level of EBs and the distribution of EB types varied according to gender, and the NQs were different according to EB types. The results of this study are expected to contribute to the establishment of customized strategies for improvement by identifying major nutritional problems by gender and the EB types of university students.

• Journal of Nutrition and Health
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• v.48 no.6
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• pp.558-570
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• 2015

Purpose: The objective of this study is to investigate the work performances and the factors contributing to the work performance of nutrition teachers and school dieticians according to employment status in Daejeon and Chungcheongnamdo. Methods: A survey was conducted among 415 school dieticians from selected elementary, middle, and high schools in the area. This survey was used for analysis of the general characteristics and the status of working and foodservice environments. The frequency of occurrence was measured using the ${\chi}^2$-test while analysis of differences in work performance of 57 variables grouped according to 12 categories by mean ${\pm}$ SD was performed using student t-test. In addition, a regression analysis was performed to assess the influence of occupational (working and foodservice) environment on work performances. Results: All 14 environmental factors including general characteristics were different between nutrition teachers and school dieticians. In 12 of 57 variables there were significant differences in work performance between the two groups. When compared using average work performance, 5 domains showed significant difference in work performance between the two groups. These 5 domains were other works (T = 6.050), dietary habit guide (T = 4.789), menu (nutrition) management (T = 3.524), foodservice administration and evaluation (T = 2.757), and production and service management (T = 2.588). Overall, the work performances of nutrition teachers were comparably higher than those of school dietitians. A correlation analysis between occupational (working or foodservice) environments and work performances of the two groups showed that the work performances of nutrition teachers were influenced by the number of employees, number of students, meal frequency a day, annual salary, age, foodservice years of school, and school type. Conclusion: Meanwhile, the work performances of school dieticians were influenced by the number of students, number of employees, meal frequency a day, work hour, education level, age, school type, and service years as a dietitian.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.107-122
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• 2017

Volatility in the stock market returns is a measure of investment risk. It plays a central role in portfolio optimization, asset pricing and risk management as well as most theoretical financial models. Engle(1982) presented a pioneering paper on the stock market volatility that explains the time-variant characteristics embedded in the stock market return volatility. His model, Autoregressive Conditional Heteroscedasticity (ARCH), was generalized by Bollerslev(1986) as GARCH models. Empirical studies have shown that GARCH models describes well the fat-tailed return distributions and volatility clustering phenomenon appearing in stock prices. The parameters of the GARCH models are generally estimated by the maximum likelihood estimation (MLE) based on the standard normal density. But, since 1987 Black Monday, the stock market prices have become very complex and shown a lot of noisy terms. Recent studies start to apply artificial intelligent approach in estimating the GARCH parameters as a substitute for the MLE. The paper presents SVR-based GARCH process and compares with MLE-based GARCH process to estimate the parameters of GARCH models which are known to well forecast stock market volatility. Kernel functions used in SVR estimation process are linear, polynomial and radial. We analyzed the suggested models with KOSPI 200 Index. This index is constituted by 200 blue chip stocks listed in the Korea Exchange. We sampled KOSPI 200 daily closing values from 2010 to 2015. Sample observations are 1487 days. We used 1187 days to train the suggested GARCH models and the remaining 300 days were used as testing data. First, symmetric and asymmetric GARCH models are estimated by MLE. We forecasted KOSPI 200 Index return volatility and the statistical metric MSE shows better results for the asymmetric GARCH models such as E-GARCH or GJR-GARCH. This is consistent with the documented non-normal return distribution characteristics with fat-tail and leptokurtosis. Compared with MLE estimation process, SVR-based GARCH models outperform the MLE methodology in KOSPI 200 Index return volatility forecasting. Polynomial kernel function shows exceptionally lower forecasting accuracy. We suggested Intelligent Volatility Trading System (IVTS) that utilizes the forecasted volatility results. IVTS entry rules are as follows. If forecasted tomorrow volatility will increase then buy volatility today. If forecasted tomorrow volatility will decrease then sell volatility today. If forecasted volatility direction does not change we hold the existing buy or sell positions. IVTS is assumed to buy and sell historical volatility values. This is somewhat unreal because we cannot trade historical volatility values themselves. But our simulation results are meaningful since the Korea Exchange introduced volatility futures contract that traders can trade since November 2014. The trading systems with SVR-based GARCH models show higher returns than MLE-based GARCH in the testing period. And trading profitable percentages of MLE-based GARCH IVTS models range from 47.5% to 50.0%, trading profitable percentages of SVR-based GARCH IVTS models range from 51.8% to 59.7%. MLE-based symmetric S-GARCH shows +150.2% return and SVR-based symmetric S-GARCH shows +526.4% return. MLE-based asymmetric E-GARCH shows -72% return and SVR-based asymmetric E-GARCH shows +245.6% return. MLE-based asymmetric GJR-GARCH shows -98.7% return and SVR-based asymmetric GJR-GARCH shows +126.3% return. Linear kernel function shows higher trading returns than radial kernel function. Best performance of SVR-based IVTS is +526.4% and that of MLE-based IVTS is +150.2%. SVR-based GARCH IVTS shows higher trading frequency. This study has some limitations. Our models are solely based on SVR. Other artificial intelligence models are needed to search for better performance. We do not consider costs incurred in the trading process including brokerage commissions and slippage costs. IVTS trading performance is unreal since we use historical volatility values as trading objects. The exact forecasting of stock market volatility is essential in the real trading as well as asset pricing models. Further studies on other machine learning-based GARCH models can give better information for the stock market investors.

• Radiation Oncology Journal
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• v.14 no.4
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• pp.281-290
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• 1996

Purpose : Chest irradiation leads to a significant cardiac injury in a number of patients. To prevent, or to reduce the risk of radiation-induced cardiac injury, pentoxifylline(PTX), a haemorrheologic agent that improves the blood flow through small blood capillaries has been employed. Materials and Methods : One hundred and eighty ICR mice were divided into three study groups: control, radiation alone, and radiation-pentoxifylline. Each group was subdivided into 12 subgroups: 1 3, 6 and 10 days and 2, 3, 4, 6, 8, 12, 16 and 20 weeks by observation Period after irradiation. The total 15Gy of radiation was delivered in a single fraction through anterior mediastinal port. Pentoxifylline was injected subcutaneously daily 50mg/kg to the back of the mice from the first day of irradiation throughout the observation period. The mice of each group after a certain observation period were sacrificed and sectioned for histopathologic examination of the heart. Result : The findings of acute radiation-induced carditis i.e., heterophilic infiltration and vacuolization and ballooning of endothelial cells were observed upto 6 weeks and reduced sharply afterwards. The late radiation effects including pericarditis with mononuclear cell infiltration, pericardial fibrosis, endothelial cell changes, myocardial degeneration and fibrosis present from 4 weeks onwards after irradiation but with various degree of severity. The overall process of pathologic changes of radiation-pentoxifylline group was similar to those of radiation alone group but the duration of acute stage was relatively short and the severity of late cardiac toxicity was much lesser compared with those of radiation alone group. Conclusion : Pentoxifylline can effectively reduce the late radiation-induced cardiac injury and reslve the acute effects relatively rapidly.