• Korean Journal of Construction Engineering and Management
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• v.11 no.4
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• pp.22-31
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• 2010

Because the estimated cost at early stage has great influence on decisions of project owner, the importance of early cost estimation is increasing. However, it depends on experience and knowledge of the estimator mainly due to shortage of information. Those tendency developed into case-based reasoning(CBR) method which solves new problems by adapting previous solution to similar past problems. The performance of CBR model is affected by attribute weight, so that its accurate determination is necessary. Previous research utilizes mathematical method or subjective judgement of estimator. In order to improve the problem of previous research, this suggests CBR schematic cost estimation method using genetic algorithm to determine attribute weight. The cost model employs nearest neighbor retrieval for selecting past case. And it estimates the cost of new cases based on cost information of extracted cases. As the result of validation for 17 testing cases, 3.57% of error rate is calculated. This rate is superior to accuracy rate proposed by AACE and the method to determine attribute weight using multiple regression analysis and feature counting. The CBR cost estimation method improve the accuracy by introducing genetic algorithm for attribute weight. Moreover, this makes user understand the problem-solving process easier than other artificial intelligence method, and find solution within short time through case retrieval algorithm.

• Journal of dental hygiene science
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• v.5 no.1
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• pp.1-5
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• 2005

Ethical perception may be thought of as 'professional skills'. Despite this, however, the dental hygiene curriculums tend to disregard ethics education. This paper describes ethical perception in dental hygiene students. Questionnaire surveys were conducted for 374 in dental hygiene students. For statistical analyses of collected data, the multiple linear regression were adopted. Demand as necessity of dental ethics education, clinical practice exercise, practice of work ethics education were found to have significant major effects on basic ethics perception. The major variables which related to the licensure and health care law and teamwork were to knowledge of revised ethics code of dental hygienist and to demand as necessity of dental ethics education. The major variables influencing the professional protocol were to knowledge of revised ethics code of dental hygienist, to demand as necessity of dental ethics education, role model for learning ethical principles. Revised ethics code of dental hygienist was the most important factor affecting professional protocol. The major variables influencing the decision-making were to demand as necessity of dental ethics education, to knowledge of revised ethics code of dental hygienist, clinical practice exercise, role model for learning ethical principles (church). About 88.4% of the students unawared to knowledge of revised ethics code of dental hygienist and perception of professional protocol of the students awared to knowledge of revised ethics code of dental hygienist was $3.44{\pm}0.23$ (p=0.000).

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.614-620
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• 2011

The purpose of this study was to provide basic data for developing the practical park management. For this, satisfaction degree, satisfaction factors and estimated model by satisfaction variables of visitors analyzed through a questionnaire survey in Naejangsan National Park, Korea. In the evaluation of the satisfaction, variables of 'Lack of public facility'. 'Lack of use program', 'Lack of facility to stay' 'Charge of user fee, parking fee' and 'Exorbitant pay' at Naejangsan park office and 'Charge of user fee, parking fee', 'Lack of use program' and 'Lack of facility to stay' at Baekam park office was more unsatisfied than any other variable. Satisfaction factors by Factor Analysis were loaded with 'Facility management' at Naejangsan park office(34.3%) and 'user management' at Baekam park office(45.6%) by the highest contribution degree. In estimated model of satisfaction by Multiple Regression Analysis showed in order of 'damage of trail', 'Lack of commercial facility', and 'Littering problem' at Naejangsan park office and 'damage of cultural and historic resource', 'Lack of commercial facility', 'Touting' at Baekam park office. So, Naejangsan National Park needed intensive management policy and institutional apparatus for facility management and user education.

• Food Science and Preservation
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• v.10 no.2
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• pp.125-130
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• 2003

This study was carried out to investigate the thermo-physical properties and design Freezing time prediction model from data of freezing test of Kimchi. Density of Kimchi were measured as 1001.9 ${\pm}$0.03 kg/㎥ at unfrozen state, 987.0 ${\pm}$0.07 kg/㎥ at frozen state and volume of the Kimchi expanded 4.67% at -l5$^{\circ}C$. Initial freezing point of Kimchi and seasoning were -4.0$^{\circ}C$ and -2.5$^{\circ}C$, respectively. Freezing ratio of Kimchi were estimated more than 50％ at -5.0$^{\circ}C$, more than 75% at -l0$^{\circ}C$ and approximately 90% at -25$^{\circ}C$. To obtain equation for freezing time prediction of Kimchi, freezing time(Y) was regressed against the reciprocal( $X_3$) of difference of initial freezing point and freezing medium temperature, reciprocal( $X_4$) of surface heat transfer coefficient, the initial temperature( $X_1$) and thickness( $X_2$) of samples. As results of the multiple regression analysis, equations were obtained as follows. Y$_{kimchi}$=3.856 $X_1$+13982.8 $X_2$+8305.166 $X_3$+ 3559.181 $X_4$-639.189( $R^2$=0.9632). These equations shown better results than previous models, and the accuracy of its was very high as average absolute difference of about 10% in the difference between the fitted and experimental results.

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.542-554
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• 1989

The skyrocketing inflation of medical costs has become a major health problem among most developed countries. Korea, which recently covered the entire population with National Health Insurance, is facing the same problem. The proportion of health expenditure to GNP has increased from 3% to 4.8% during the last decade. This was remarkable, if we consider the rapid economic growth during that time. A few policy analysts began to raise cost containment as an agenda, after recognizing the importance of medical cost inflation. In order to Prepare an appropriate alternative for the agenda, it is necessary to find out reasons for the cost inflation. Then, we should focus on the reasons which are controllable, and those whose control are socially desirable. This study is designed to articulate the theory of medical cost inflation through literature reviews, to find out reasons for cost inflation, by analyzing aggregated data with a deterministic model. Finally to identify determinants of changes in both medical demand and service intensity which are major reasons for cost inflation. The reasons for cost inflation are classified into cost push inflation and demand pull inflation, The former consists of increases in price and intensity of services, while the latter is made of consumer derived demand and supplier induced demand. We used a time series (1983-1987), and cross sectional (over regions) data of health insurance. The deterministic model reveals, that an increase in service intensity is a major cause of inflation in the case of inpatient care, while, more utilization, is a primary attribute in the case of physician visits. Multiple regression analysis shows that an increase in hospital beds is a leading explanatory variable for the increase in hospital care. It also reveals, that an introduction of a deductible clause, an increase in hospital beds and degree of urbanization, are statistically significant variables explaining physician visits. The results are consistent with the existing theory, The magnitude of service intensity is influenced by the level of co-payment, the proportion of old age and an increase in co-payment. In short, an increase in co-payment reduced the utilization, but it induced more intensities or services. We can conclude that the strict fee regulation or increase in the level of co-payment can not be an effective measure for cost containment under the fee for service system. Because the provider can react against the regulation by inducing more services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.380-390
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• 2017

This study examined the relationship between social support, social participation and physical functioning among older adults in community senior centers. The subjects of this study were 194 persons aged 60 years or older who participated in the senior center in K province and D city, from June 16 to June 30, 2016. The collected data were analyzed using descriptive statistics, T-test, one way ANOVA, Pearson correlation analysis, multiple regression analysis, and structural model analysis using IBM SPSS Statistics 23.0 and IBM AMOS 21.0. The result showed that the social support and physical functioning of the elderly in the community were above normal, and social participation was somewhat low. Interestingly, an analysis of the physical functioning between social support, social participation and depression revealed significant correlations. The factors affecting the physical health were 23.4% of the respondents who had a significant influence on social support and leisure activities. In addition, the result of structural model analysis showed that social support had a significant influence on the social participation, depression and physical functioning. Therefore, the results suggests that the development of educational programs and an age-friendly environment should be actively provided to older adults in the community by strengthening the physical function through social support for active ageing.

• Journal of the Korean Society of Child Welfare
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• no.27
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• pp.121-151
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• 2008

The purpose of this study is to examine the moderated mediation effects of parenting functioning on the relations between deviant peer's influences and delinquent behaviors in adolescence. To investigate the moderated mediation effects, simple slope test and bootstrapping method based on multiple linear regression(MLR) model were used. This study used data from wave 1-2(2003-2004) of the Korea Youth Panel Survey(KYPS). Results showed that poorer parenting increased the probability that adolescents would affiliated with deviant peers, and more association with deviant peers, in turn, was related to delinquency. There was statistical significant interaction between affiliation with deviant peers and parenting in the model for delinquency. It implied that the relation between deviant peers and delinquency depends on the quality of parenting. Finally, indirect effect of earlier parenting on delinquent behavior through affiliation with deviant peers was moderated by later parenting. These results help clarify the conditions under which exposure to parenting behaviors can buffer the negative effect of deviant best friends on delinquent behaviors in adolescence. Practice and policy implications as well as further research topic were discussed to aid the search for highly effective preventive and treatment interventions.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1080-1084
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• 2011

Predictive model for estimating total contents of cadmium (Cd) and lead (Pb) was developed by stepwise multiple-regression analysis using chemical properties and extractable contents of metal in paddy soil adjacent to abandoned mines in 2009 and 2010. Soil properties, e.g. pH, electrical conductivity (EC), organic matter (OM), available phosphorus ($P_2O_5$), and exchangeable cations (i.e. Ca, Na, K, Mg) were measured. Total contents of Cd and Pb as well as extractable contents of metals were analyzed by ICP-OES. Results showed that the total and extractable contents were estimated to be 3.55 and $0.27mg\;kg^{-1}$ in Cd and 83.38 and $24.32mg\;kg^{-1}$ in Pb on the average. From stepwise analysis, it was found that the contents of extractable Cd, Zn, Cu, as well as exchangeable Na were significantly influenced on estimation of the total contents of Cd in soil. Moreover, it also showed that the contents of extractable Pb, Zn, and Cu significantly affected estimation of the total contents of Pb in soil. More significant relationship between estimated and measured value in total contents of Pb was observed than those of Cd ($R^2$=0.87, p<0.0001). This demonstrates that extractable contents of metal are influenced more on estimation of total contents of Cd and Pb in soil than soil properties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.56-65
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• 2019

The purpose of this study was to identify factors associated with character of nursing students using ecological theory. A descriptive cross-sectional study was conducted with 296 nursing students. Collected data from self report questionnaires were analyzed using descriptive statistics, t-test, ANOVA and multiple regression with SPSS WIN 21.0. The Results of this study were as follows. A total of 2 models were examined according to individual, microsystem in ecological system theory. In the first model including individual factors, positive emotion, communication ability were significant factors explain character of nursing students. In the second model adding micro system factors family strength and major satisfaction found to be significant factors. The prediction factors of nursing student' character were communication ability (${\beta}=.431$, p<.001), major satisfaction (${\beta}=.310$, p<.001) and family strength (${\beta}=.176$, p<.001). The explanation power was 55.6%. These results showed that factors affecting character of nursing students are communication ability, major satisfaction, and family strength. Therefore, we suggest to develop various character education programs considering these factors.

• Journal of Korean Society on Water Environment
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• v.35 no.4
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• pp.316-331
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• 2019

Carbon dioxide($CO_2$) emission from rivers to the atmosphere is a key component in the global carbon cycle. Most of the rivers are supersaturated with $CO_2$. At a global scale, the amount of $CO_2$ emission from rivers is reported to be five-fold greater than that from lakes and reservoirs, but relevant data are rare in Korea. The objectives of this study is to estimate the $CO_2$ net atmospheric flux(NAF) from the upstream of Gangjeong-Goryeong Weir(GGW), Dalseong Weir(DSW), Hapcheon-Changnyeong Weir(HCW), and Changnyeong-Haman Weir(CHW) located in Nakdong River South Korea) using field and laboratory experiments and to apply data mining techniques to develop parsimonious prediction models that can be used to estimate $CO_2$ NAF with physical and water quality variables that can be collected easily. As a result, the study sites were all heterotrophic systems that often released $CO_2$ to the atmosphere, except when the algal photosynthesis was active.The median $CO_2$ NAF was minimum $391.5mg-CO_2/m^2$ day at GGW and maximum $1472.7mg-CO_2/m^2$ day at DSW. The $CO_2$ NAF showed a negative correlation with pH and Chl-a since the overgrowth of the algae consumed $CO_2$ in the water and increased the pH. As the parsimonious multiple regression model and random forest model developed, this study showed an excellent performance with the $Adj.R^2$ value higher than 0.77 in all weirs. Thus, these methods can be used to estimate $CO_2$ NAF in the river even if there is no $pCO_2$ measurement data.