• KIPS Transactions on Software and Data Engineering
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• v.4 no.11
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• pp.509-520
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• 2015

College Scholastic Ability Test(CSAT) is a primary test to evaluate the study achievement of high-school students and used by most universities for admission decision in South Korea. Because its level of difficulty is a significant issue to both students and universities, the government makes a huge effort to have a consistent difficulty level every year. However, the actual levels of difficulty have significantly fluctuated, which causes many problems with university admission. In this paper, we build two types of data-driven prediction models to predict correct answer rate and to identify significant factors for CSAT English test through accumulated test data of CSAT, unlike traditional methods depending on experts' judgments. Initially, we derive candidate question-specific factors that can influence the correct answer rate, such as the position, EBS-relation, readability, from the annual CSAT practices and CSAT for 10 years. In addition, we drive context-specific factors by employing topic modeling which identify the underlying topics over the text. Then, the correct answer rate is predicted by multiple linear regression and level of difficulty is predicted by classification tree. The experimental results show that 90% of accuracy can be achieved by the level of difficulty (difficult/easy) classification model, whereas the error rate for correct answer rate is below 16%. Points and problem category are found to be critical to predict the correct answer rate. In addition, the correct answer rate is also influenced by some of the topics discovered by topic modeling. Based on our study, it will be possible to predict the range of expected correct answer rate for both question-level and entire test-level, which will help CSAT examiners to control the level of difficulties.

• Health Policy and Management
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• v.24 no.2
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• pp.136-142
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• 2014

Background: This study is to research on how hypertension control is associated with adherence in newly diagnosed hypertension patients. Methods: The study is based on 255,916 patients who were diagnosed with hypertension in 2009 and didn't have any previous medical history of hypertension or associated complication for the past year using data collected by National Health Insurance Corporation. Newly diagnosed hypertension patients are divided into two group by visiting medical center numbers (more than 300 days was adherence group, if not non-adherence group). Patients are considered to have successfully controlled their hypertension based on blood pressure measured by health examination. Chi-square test and logistic regression, repeated measured analysis of variance was used to analyze. Results: The relations between adherence and hypertension control show that 1.12 times of patients in adherence group was able to control their hypertension. The additional analysis proves that adherence group are more decreased level of blood pressure than non-adherence group except for patients who are over 70. Comparison of the average of systolic blood pressure and diastolic blood pressure between adherence and non-adherence groups shows that the blood pressure has been significantly among the adherence group. Conclusion: The study proves that constant treatment for hypertension could control the blood pressure and encourages patients to put more effort for persistent treatment. It also shows that hypertension treatment are more effective in younger patients than the elderly and strategies of approaching are different depending on age.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.431-440
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• 2008

Turbid water or suspended sediment is associated with negative effects on aquatic organisms; fish, aquatic invertebrate, and periphyton. Effects of turbid water on fish differ depending on their developmental stage and a level of turbidity. Low turbid water may cause feeding and predation rates, reaction distance, and avoidance in fish, and it could make fish to die under high turbidity and long period. Therefore, it is very important to find out how turbid water or suspended sediment can affect fish in domestic watersheds. The objectives of this study were 1) to introduce international case studies and their standards to deal with suspended sediment, 2) to determine acute toxicity in 4 major freshwater fishes, and 3) to determine in relation to adverse effect of macroinvertebrates and fish. Impacts of turbid water on fish can be categorized into direct and indirect effects, and some factors such as duration and frequency of exposure, toxicity, temperature, life stage of fish, size of particle, time of occurrence, availability of and access to refugia, etc, play important role to decide magnitude of effect. A review of turbidity standard in USA, Canada, and Europe indicated that each standard varied with natural condition, and Alaska allowed liberal increase of turbidity over natural conditions in streams. Even though acute toxicity with four different species did not show any fatal effect, it should be considered to conduct a chronic test (long-term) for more detailed assessment. Compared to the control, dominance index of macroinvertebrates was greater in the turbid site, whereas biotic index, species diversity index, species richness index, and ecological score were smaller in the turbid site. According to histopathological analysis with gills of macroinvertebrate and fishes, morphological and physiological modification of gills due to suspended sediments can cause disturbance of respiration, excretion and secretion. In conclusion, in order to maintain good and healthy aquatic ecosystem, it is the best to minimize or prevent impact by occurrence of turbid water in stream and reservoir. We must make every effort to maintain and manage healthy aquatic ecosystem with additional investigation using various assessment tools and periodic biomonitoring of fish.

• Korea Journal of Hospital Management
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• v.10 no.4
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• pp.23-50
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• 2005

The main objectives of this study are to compare the regional differences and to analyse the affecting factors of customer satisfaction. The subjects are 9 hospitals(5 Daegu region, 4 Seoul region) patient satisfaction index that were surveyed the 2004 Hospital Accreditation Program performed by KHIDI(Korea Health Industry Development Institute) and MOHW(Ministry of Health and Welfare). The sample used in this study consisted of 450 inpatients and 454 outpatients. The survey instrument is composed of physical environment items, physician factors, nursing staff factors, ancillary staff factors, administrative procedure items, and quality of hospital stay items. And overall satisfaction, intent to revisit, and intent to recommend as dependent variables are measured. Basically, the reliability and validity of survey items was evaluated. And the T-test was performed to compare regional differences of customer satisfaction. Finally to analyse the affecting factors on overall satisfaction, and customer loyalty(intent to revisit and intent to recommend), the multiple regression analysis was used. This study shows firstly, the Daegu region's patient satisfaction level of inpatients and outpatients is lower than Seoul region. Especially, nursing staff factors and quality of hospital stay items are very low on inpatient's satisfaction. Also all independent variables except the sufficiency of goods in hospital stand are very low on outpatient's satisfaction. Secondly, as a result of multiple regression analysis, ancillary staff factors(Beta=0.281) have a significant effect on overall satisfaction of inpatient cases in Daegu region. In regard to intent to revisit and intent to recommend, physical environment factors have a significant effect. Thirdly, in Seoul region, physical environment factors(Beta=0.430) have a significant effect on overall satisfaction of inpatient cases. In regard to intent to revisit and intent to recommend, administrative procedure items and nursing staff factors have a significant effect, respectively. In conclusion, these results indicate that hospitals in Daegu region make an effort to improve the customer satisfaction level, especially, of physical environment factors on inpatients and administrative procedure factors on outpatients

• The Journal of Korean Society for School & Community Health Education
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• v.9 no.1
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• pp.127-142
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• 2008

Objectives: This study was conducted to analyze the stress level of teachers and their management measures, the school environments affecting on the characteristics of teachers and how the health status of school teachers have effect on the stress level of school teachers in our nation. Methods: The study conducted to 900 high school teachers in Seoul, Busan, Incheon, Kwangju and Daejeon. The investigation was carried out for 5 months from March 10 to July 10, 2007. Results: The stress level of test subjects was $15.55{\pm}3.14$ in 30 point scale (51.8 in 100 point scale). The overall level scored 3.71 in 8 point scale (46.4 in 100 point scale), and the average of stress management methods was 15.51 in 36 point scale (55.8 in 100 point scale). Therefore, stress management methods should be developed to solve stress and to reduce the causes of stress variables of high school teachers to teach students healthily in good health status without stress, which can allow us to have healthy families and society though the ripple effects. In addition, the related governments, organizations, related experts and teachers should take effort by paying more attention to increase the life quality of teachers to enjoy healthy life.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.4
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• pp.519-530
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• 2009

The purpose of this study is to investigate the effects of the prior knowledge, the market position and negative information of the alliance apparel product on consumer attitude including preference, purchase intent and utility. Smart wear with MP3 was selected for the alliance apparel product. Negative information was manipulated into two types-product related and brand related negative information. 251 subjects participated for the study. For the data analysis, reliability test and three way analysis of variance were conducted. The results showed that when the partner brand has the higher market position, subjects with high prior knowledge revealed preference for the alliance apparel product more. When the partner brand has the higher market position, the subjects who were given the negative information on the alliance apparel product reported preference and utility more than the ones who were given the negative information on the company. The findings of the study imply that apparel industries should make an effort to establish the positive corporate image as well as to produce high quality apparel product. Also marketers should provide consumers with the knowledge about brand new alliance apparel product.

• Journal of Korean society of Dental Hygiene
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• v.10 no.1
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• pp.141-156
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• 2010

Objective : This study was conducted to examine the relationships among health & oral health promotion behavior according to BMI. The subjects in this study were 704 high school students. Methods : A survey was conducted, and Chi-square, T-test, ANOVA, and Pearson's correlation coefficient were used for data analysis. The findings of the study were as follows; Results : Man is normal weight group accounted for 65.9%, and women is 69.7%(p<0.001). Health & oral health promotion behavior of nutrition(p<0.01) and exercise(p<0.001) that men were higher than women. But health responsibility was higher to women(p<0.001). As to the relationship for the BMI to health promotion behavior, nutrition is over weight group accounted for 3.45, obesity group 3.43, normal weight group 3.26 and under weight group 3.16(p<0.05). Exercise is over weight group accounted for 2.70(p<0.05), and nutrition for oral health is obesity group accounted for 3.47(p<0.05). As for correlation among the BMI, stronger social support, more exercise, better nutrition for oral health, there was a statistically significant relationship between BMI. As the factors significantly affecting BMI, their satisfaction level with exercise, nutrition for oral health, life appreciation, stress management for oral health. Conclusions : This study suggested that health & oral health promotion behavior of high school students in an effort to help improve policy setting on health projects and determine how to teach teens to promote their health throughout their lives.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.361-374
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• 2015

Endocirne disruptors (EDs) can cause fertility decrease, developmental disorder, and even cancer in animals. Until 90's, EDs were used in various synthetic products including paints, coatings, detergents, plastics, and plasticizers. Currently, in several countries, the production, trade and use of EDs or EDs-suspected chemicals have been regulated while activity to screen the alternatives for EDs including bisphenol-A, phthalate and nonylphenol is active. Although various toxicity test method was developed and applied for screening of alternatives, however, the safety of alternatives has been not fully demonstrated. Some alternatives have high structural similarity with existing EDs, raising the possible risk of endocrine disruption by alternatives. In an effort to develop the safe alternatives, we reviewed the effects of EDs such as bisphenol-A, phthalates, nonylphenol and their substituents. In addition, in-silico analysis for endocrine disrupting activities of some alternatives was presented.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.120-135
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• 2014

This research aimed to investigate the effect of business management of Korean restaurants on business performance and to propose an alternative. For this investigation, a survey was carried out targeting Korean restaurant managers in the capital area, and with 360 copies as sample, factor analysis, difference test, and multiple regression analysis were conducted. As a result of analysis, among the factors of business management of Korean restaurants, only information management and fund management appeared to have effects on both financial performance and nonfinancial performance. This means, in case of Korean restaurants, business performance can be improved by understanding every environment about food service management and customer demands, by investing fund in the right place, and by managing inefficient expenses. Therefore, it is most important for a Korean restaurant manager to cultivate knowledge in management and to put effort into cost-reduction of all employees.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.169-174
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• 2020

Purpose: Periodontal disease causes tooth loss and is associated with cardiovascular diseases, diabetes, and rheumatoid arthritis. The present study proposes using a deep learning-based object detection method to identify periodontally compromised teeth on digital panoramic radiographs. A faster regional convolutional neural network (faster R-CNN) which is a state-of-the-art deep detection network, was adapted from the natural image domain using a small annotated clinical data- set. Materials and Methods: In total, 100 digital panoramic radiographs of periodontally compromised patients were retrospectively collected from our hospital's information system and augmented. The periodontally compromised teeth found in each image were annotated by experts in periodontology to obtain the ground truth. The Keras library, which is written in Python, was used to train and test the model on a single NVidia 1080Ti GPU. The faster R-CNN model used a pretrained ResNet architecture. Results: The average precision rate of 0.81 demonstrated that there was a significant region of overlap between the predicted regions and the ground truth. The average recall rate of 0.80 showed that the periodontally compromised teeth regions generated by the detection method excluded healthiest teeth areas. In addition, the model achieved a sensitivity of 0.84, a specificity of 0.88 and an F-measure of 0.81. Conclusion: The faster R-CNN trained on a limited amount of labeled imaging data performed satisfactorily in detecting periodontally compromised teeth. The application of a faster R-CNN to assist in the detection of periodontally compromised teeth may reduce diagnostic effort by saving assessment time and allowing automated screening documentation.