• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.55-61
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• 1996

The objective of this paper is to show an optimal design model for branched water supply system which also can find the optimal location of pumping stations using linear programming. GIS is utilized in this model to better handle the data and the results front the optimization. The developed model considers hydraulic influences of some appurtenances such as supply tunnels and a filtration plant The model also considers tunnel construction cost which should be treated differently from pipe construction cost Different from other models presently available, the model guarantees a nonnegative pressure at every junction node in the system. The objective function includes annual operation cost (electricity rate) ill addition to initial construction cost, thus producing a more reasonable decision. The model selects the optimal diameter not in the form of continuous number but in the form of commercial discrete diameter (pipe size) using the pipe lengths as decision variables instead of pipe diameters. The model not only determines the optimal pumping head for each pumping station but also finds the optimal location and number of pumping stations. GIS is used to handle hydraulic and budgetary data automatically and to visualize the results for the of optimal design of the system. The model has been applied to an existing water supply system. 'The results show that the optimization model with the aid of GIS is helpful in the decision-nulling process for the design of more economical systems, and can be dot into practice successfully.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.7
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• pp.846-851
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• 2005

In this paper, we propose Genetic Algorithms(GAs)-based Optimized Polynomial Neural Networks(PNN). The proposed algorithm is based on Group Method of Data Handling(GMDH) method and its structure is similar to feedforward Neural Networks. But the structure of PNN is not fixed like in conventional neural networks and can be generated in a dynamic manner. As each node of PNN structure, we use several types of high-order polynomial such as linear, quadratic and modified quadratic, and it is connected as various kinds of multi-variable inputs. The conventional PNN depends on the experience of a designer that select the number of input variables, input variable and polynomial type. Therefore it is very difficult to organize optimized network. The proposed algorithm leads to identify and select the number of input variables, input variable and polynomial type by using Genetic Algorithms(GAs). The aggregate performance index with weighting factor is proposed as well. The study is illustrated with tile NOx omission process data of gas turbine power plant for application to nonlinear process. In the sequel the proposed model shows not only superb predictability but also high accuracy in comparison to the existing intelligent models.

• The Korean Journal of Community Living Science
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• v.17 no.1
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• pp.141-154
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• 2006

The purpose of this study is to provide the information of the aged olds for which basic data are almost no available. The subjects were divided on the base of age 75. The elderly under 75 were named 'the young olds' and over 75 were 'the aged olds'. The aim of this research is to promote health and to improve nutrition, and the survey was made for health promotion behaviors, habits against health risk, dietary management status and diet intake. And it was conducted by 24 hr-recall method and analyzed by nutrients intake. 242 subjects were collected in 12 cities or counties in Gyeonggi Province and 20 elderly people (10 male and 10 female) were selected out of 1 village in each district. Questionnaire about health behavior and dietary management was carried out by interview method through regional home extension workers. Statistical analyses were made by SAS (version 8.1) and Chi-square tests and General Linear Models were used. Out of the subjects the aged olds over 75 was 31.9%, elementary school educated (93.5%), with spouse (40.3%), with adult children(28.6%), monthly living cost of 500-1,000 thousand won(40.3%). Mean age was 78.82 years compared with 69.75 years of the young olds. 46.8% of the aged olds used monthly pocket money over 1000 won and it was lower than 63.3% of the young olds. Only half of the aged olds had regular exercise of walking (77.8%) or with athletic equipment (17.8%). However, the young olds did more frequent walking (82.1 %) and less exercise with athletic equipment (4.8 %), which was significantly different. Kinds of disease were different with the young or the aged olds, as more proportion of cardiovascular disease(37.9%) for the young olds and joint lumbago neuralgia(41.6%) for the aged olds. Dietary management was good (3 meals per day: 93.4%, fixed mealtime: 72.4%, and regular amount: 79.9%). But there was significant difference in side dish varieties and kinds of snacks; for the aged olds only 8% had over 5 sorts (compared with 18.8% of the young olds) and the kinds of snacks were cookie, candy, juice, carbonated beverage for the aged olds (compared with noodle, milk, soybean-milk for young olds). The ratio of nutrients intake (energy, riboflavin and niacin) with RDA was significantly higher for the aged olds than that of the young olds. The surveyed subjects had no difficulties in Activities of Daily Living (ADL), but some of the aged olds had difficulties in Instrumental Activities of Daily Living (IADL) like housekeeping, using transportation, going shopping and making phone calls. These results suggest that low quality of life is linked with low economic status of the rural elderly and congregate meal at village hall would be required because of the lack of side dishes variety for the aged olds. And nutrition education program about good snacks and exercise practice would be needed for the aged olds. By operating nutrition education program the aged olds would enjoy better quality life maintaining or ameliorating IADL abilities.

• The Korean Journal of Community Living Science
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• v.17 no.1
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• pp.123-139
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• 2006

The purpose of this study is to search how to promote health and improve nutrition and health care of the elderly people in rural area. Behaviors for health promotion and habits against health risk were surveyed. Dietary management was analyzed for surveyed nutrient intake by 24 hr -recall method. 242 subjects were collected in 12 cities or counties in Gyeonggi Province and 20 elderly people (10 male and 10 female) were selected out of 1 village in each district. Questionnaire for health behavior and dietary management was carried out by trained interviewers. Statistical analyses were made by SAS (version 8.1) and Chi-square tests and General Linear Models were used. Characteristics of the elderly people were 61-74 year-olds (68.2%), elementary school educated (78.4%), with spouse (51.7%), monthly living cost of 500-1,000 thousand won(43.4%), and monthly pocket money of 50-100 or 100-200 thousand won(33.5%, 26.5%). 41.4% of the subjects checked up medical examination regularly. The alcohol drinking status was significantly different according to gender: high no-drink rate of female (52.5%) and low no-drink rate of male (25.6%). Kinds of disease were different according to gender: higher proportion of cardiovascular disease(46.3%) and diabetes mellitus(8.1 %) in male and joint lumbago neuralgia(44.4%) and osteoporosis(8.6%) in female. Gastrointestinal complaints were nausea (69.0%) and chronic indigestion (17.8%). Constipation (12.0%) and vomiting (4.3%) were more frequent in female. Dietary management was good (3 meals per day: 93.4%., dining with family: 72.4%, regular mealtime: 72.4%, and 3-4 times of snacks per week: 44.9%) except side dish taking of 3-4 kinds only. However, almost one-third of the female elderly ate alone (30.6%) which was well compared with one-fifth of the male (19.7%). And food and nutrients intake were not significantly different according to gender except that male elderly's intake of energy and protein was lower than that of female's. The surveyed subjects had no difficulties in Activities of Daily Living (ADL), but some female elderly had some difficulties with Instrumental Activities of Daily Living (IADL) like working at home, using transport, and going shopping. These results suggest that low quality of life linked with low economic status of the rural elderly and that congregate meal at village hall would be required for the female elderly eating alone. For the undernourished male elderly, it would be needed to provide snacks and to establish nutrition and health surveillance system.

• Korean Journal of Community Nutrition
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• v.21 no.6
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• pp.533-544
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• 2016

Objectives: We aimed to examine levels of physical activity, anthropometric features, and health-related quality of life (HRQoL) among Korean breast cancer survivors who reported changes in their diet after diagnosis. Methods: A total of 380 women who had been diagnosed with stage I to III breast cancer and had breast cancer surgery at least six months before the interview were included. Participants provided information on dietary change after diagnosis, post-diagnostic diet, physical activity, anthropometric measures, and HRQoL through face-to-face interview. We assessed HRQoL levels of breast cancer survivors using a validated Korean version of European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and Breast Cancer Module (BR23). We used the logistic regression and generalized linear models to identify the associations of dietary changes in relation with physical activity, anthropometry, and HRQoL. Results: The majority of participants (72.6%) reported that they have changed their diet to a healthier diet after diagnosis. Breast cancer survivors who reported to have change to a healthy diet had higher intakes of vegetables and fruits and lower intakes of red and processed meats, and refined grains than those who did not. Also, survivors with a healthy change in their diet were more likely to engage in physical activity (top vs. bottom tertile: odds ratio [OR], 1.85; 95% confidence interval [95% CI], 1.02-3.36) and have lower body mass index (BMI) (OR, 0.90; 95% CI, 0.82-0.98 for one $kg/m^2$ increment in BMI) compared to those who did not. We found that a healthy change in diet was associated with higher scores of physical functioning (p=0.02) and lower scores of constipation (p=0.04) and diarrhea (p=0.006) compared to those who did not. Conclusions: Healthy changes in diet after breast cancer diagnosis may be associated with lower levels of BMI, and higher levels of physical activity and HRQoL.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.331-342
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• 2017

Objectives: This study aimed at helping oral health prevention of the blind and related management plan, which is defined as the influence factors between missing and filled permanent teeth index and general feature and oral health behavior of the blind in Korea (estimates 229,678 persons) using data of the 6th Korea National Health and Nutrition Examination Survey from 2014 Korea Centers For Disease Control and Prevention. Methods: The blind over the age of 30 were selected as study subjects who have conducted health survey and dental inspections in KNHANES VI-2. Estimates of the subjects were 229,67 persons. For analyzing data, general linear models: GLM and covariance analysis were conducted to identify the relation between general feature and oral health behavior and missing and filled permanent teeth index. SPSS 21 statistical program was used, which is possible to conduct complex sampling design, and the significance level was 0.05. Results: The missing and filled permanent teeth index was 8.58 points. Regarding the results of the analysis, R-squared of the missing and filled permanent teeth index depending on general features of the blind was 0.839 points, which shows gender, age, residence, education level, individual income, disability rating, kinds of health insurance, marital status and recipient of basic living had an effect on the missing and filled permanent teeth index. R2 of the missing and filled permanent teeth index depending on oral health form of the blind was 0.728 points, which shows oral examination, dental treatment, smoking and toothbrushing after lunch had an effect on the missing and filled permanent teeth index. Conclusions: With the result of this study, we found the oral health actual condition of the blind in Korea. Therefore, it is considered that the government needs to introduce the personalized oral health education program to maintain oral health of the blind and to develop a program that uses braille and voice device which enables to access and utilize to improve oral health behavior that the government could use it as a reference to establish the policy plan.

• The Korean Journal of Applied Statistics
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• v.30 no.6
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• pp.809-825
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• 2017

The number of TV entertainment shows is increasing. Competition among programs in the entertainment market is intensifying since cable channels air many entertainment TV shows. There is now a need for research on program ratings and the number of episodes. This study presents predictive models for entertainment TV show ratings and number of episodes. We use various data mining techniques such as linear regression, logistic regression, LASSO, random forests, gradient boosting, and support vector machine. The analysis results show that the average program ratings before the first broadcast is affected by broadcasting company, average ratings of the previous season, starting year and number of articles. The average program ratings after the first broadcast is influenced by the rating of the first broadcast, broadcasting company and program type. We also found that the predicted average ratings, starting year, type and broadcasting company are important variables in predicting of the number of episodes.

• Journal of Korean Society of Steel Construction
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• v.15 no.5 s.66
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• pp.499-507
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• 2003

As the load is increased on the steel-concrete composite structure, its interface begins to show nonlinear behavior due to the reduction of interaction, micro-crack, slip and separation, and it causes slip-softening, Therefore, it is essential to consider the partial-interaction analysis technique. Until now, however, full-interaction or, in some instances, the linear-elastic model, which are insufficient to simulate accurate behavior, are assumed in the analysis of composite structure since the analysis method and nonlinear model for interface are very difficult and complicated. Therefore, the design of composite structure is followed by the experimental method which is inefficient-because a number of tests have to be carried out according to the design environments. In this study, we carried out the nonlinear analysis according to various interface nonlinear models by interaction magnitude, and analyzed more accurate structural behavior and performance by maximum tangential traction and slip-softening at the interface. As a result of this study. we were able to prove that the nonlinear model of interface more exactly represents behavior after yielding, such as ultimate load: that initial tangential stiffness of interface has a significant effect on the yielding load of structural members or part: and that the maximum tangential traction and slip-softening mainly effects structural yielding and ultimate load. Therefore, the structural performance of composite structure is highly dependent on the steel-concrete interface or interaction, which may result in initial tangential stiffness, maximum tangential traction and slip-softening in nonlinear model.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.1-10
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• 2017

The compact city usually provides good accessibility of residents with multiple transportation modes. However, in a compact city, annual average of travel distance per household by car is relatively short due to more congested traffic condition and larger travel cost than disperse city. As a result, total travel demand is decreasing when the region becomes more compact. Therefore compact development is regarded as one of the sustainable choices for future urban planning in many countries. This study aims at an empirical analysis of the relationship between urban compactness and travel demand based upon land-use and travel data for city of Seoul. In this study, 424 sub-districts with the mixed land-use patterns are assessed in a hexagonal diagram. The measurement is based on the relative deviation of each sector's characteristics including numbers of residence, manufacture, and trade & service. Multiple linear regression models are developed to analyze the effects of urban compactness on zonal trip generations. As a result, the trip generation rate in the residence-intensive and mixed-use areas is found to be relatively low. Furthermore, residents in high-compact areas tend to use public transport more often than residents in less compact areas.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1190-1196
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• 1997

Between July 1994 and August 1995, 78 patients underwent coronary artery bypass graft at Seoul National University Hospital. Coronary angiogram was performed one year after coronary artery bypass graft in 49 patients(62.8%) for evaluation of the graft patency and analysis of the risk factors for graft occlusion. The patency rates of both the internal mammary artery and the radial artery grafts were 100% , although three internal mammary artery grafts(5.0%) were narrowed(string sign). And that of the saphenous vein grafts were 85.2%. Multivariate analysis for the preoperative, operative, and postoperative factors was done between the widely patent and the narrowed internal mammary artery graft groups, and between the patent and the occluded saphenous vein graft groups by the general linear models procedure. Patient's age($\geq$60 years), postoperative intraaortic balloon pump insertion, bleeding, and acute renal failure were found to be the significant risk factors for internal mammary artery graft narrowing, and coronary artery size(< 1.5 mm) was the significant risk factor for the saphenous vein graft occlusion (p<0.05) . This study confirms that the arterial graft is superior to the vein graft at one-year patency rate, and suggests the risk factors for graft occlusion during the first postoperative year. Knowledge of this study may provide a basis for estimating the risk factors for graft occlusion, and thereby modifying surgical strategy and postoperative surveillance.