• Journal of the Korean Geographical Society
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• v.49 no.3
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• pp.405-422
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• 2014

Two important issues in hedonic model are to specify accurate model and delineate submarkets. While the former has experienced much improvement over recent decades, the latter has received relatively little attention. However, the accuracy of estimates from hedonic model will be necessarily reduced when the analysis does not adequately address market segmentation which can capture the spatial scale of price formation process in real estate. Placing emphasis on improvement of performance in hedonic model, this paper tried to segment real estate markets in Gangnam-gu and Jungrang-gu, which correspond to most heterogeneous and homogeneous ones respectively in 25 autonomous districts of Seoul. First, we calculated variable coefficients from mixed geographically weighted regression model (mixed GWR model) as input for clustering, since the coefficient from hedonic model can be interpreted as shadow price of attributes constituting real estate. After that, we developed a spatially constrained data-driven methodology to preserve spatial contiguity by utilizing the SKATER algorithm based on a minimum spanning tree. Finally, the performance of this method was verified by applying a multi-level model. We concluded that submarket does not exist in Jungrang-gu and five submarkets centered on arterial roads would be reasonable in Gangnam-gu. Urban infrastructure such as arterial roads has not been considered an important factor for delineating submarkets until now, but it was found empirically that they play a key role in market segmentation.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.313-326
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• 2021

This study was to introduce ecological momentary assessment and show how to apply it to real-world research. As preliminary study for sustainable development, the result explained growth model using senior's longitudinal data and suitability of multi-level model in EMA data with regression analysis. The total variance of dependent variable was determined through a base model with only intercept and approximately 47% of total variance was caused by individual differences and 53% by time point differences. Second model was used to verified that each individual has a different effect on the senior vitality and effect on time was not significant. This is because it is the result of a preliminary stage where treatment is not involved and there is no significant change in process of collecting EMA data without external intervention. Third model that add gender as an independent variable showed significant change in both time and gender. Finally compared the PRD for each model and found models that without gender variables fit the data more effectively. This suggests that studies dealing with longitudinal data such as EMA data should adopt multi-level model that can measure individual characteristics, taking into account respondents' time and context.

• Fire Science and Engineering
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• v.22 no.2
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• pp.70-83
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• 2008

This study examine the factors of job satisfaction and searches wheather job satisfaction has relation to fire official's performance of work. The purpose of this study is suggest management that can promote job satisfaction of fire officials. This is based on the survey from fire officials in Daejeon metropolitian city. For testing hypothesis casual analysis is needed the major methods of this study is used factors analysis, correlations analysis, and multi regression analysis. Following are the major finds. There are statistically significant relations between 5 independent variables (job motivations, organizational management factors, staff management factors, work environment factors, human relations factors) and job satisfaction of fire officials. But, there are no statistically significant relations between demographic variable(gender, age, position, years of serving and job satisfaction).

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.141-149
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• 2008

Recently we frequently analyze multivariate data with quite large number of variables. In such data sets, virtually duplicated variables may exist simultaneously even though they are conceptually distinguishable. Duplicate variables may cause problems such as the distortion of principal axes in principal component analysis and factor analysis and the distortion of the distances between observations, i.e. the input for cluster analysis. Also in supervised learning or regression analysis, duplicated explanatory variables often cause the instability of fitted models. Since real data analyses are aimed often at multiple purposes, it is necessary to reduce the number of variables to a parsimonious level. The aim of this paper is to propose a practical algorithm for selection of a subset of variables from a given set of p input variables, by the criterion of minimum trace of partial variances of unselected variables unexplained by selected variables. The usefulness of proposed method is demonstrated in visualizing the relationship between selected and unselected variables, in building a predictive model with very large number of independent variables, and in reducing the number of variables and purging/merging categories in categorical data.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.65-75
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• 2015

This paper analyzes the determinants of wage for the college and university graduates utilizing both individual-level and industry-level variables. We note that wage determination has multi-level structure in the sense that individual wage is influenced by individual-level variables (level-1) and industry-level (level-2) variables. Then, the assumption that individual wage is independent in the classical regression is violated. Therefore, this paper utilizes the hierarchical linear model (HLM). The major results are the followings. First, the multiple correspondence analysis including level-1 and 2 variables reveals that both level 1 and level 2 variables affects individual wages judging from the fact that the values of level 1 and level 2 variables differ across the different level of individual wage groups. Second, the decision tree analysis including level-1 and 2 variables shows that the most influential variable in wage determination is industry-level wage and the next is industry-level working hour, ages and sex in the decling order in. This suggests that the utilization of the HLM is appropriate since the characteristics of industry is important in determining the individual wage. Third, it is shown that the HLM model is the best compared to the other models which do not take level-1 and level-2 variables simultaneously into account.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.364-387
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• 2009

Female marriage immigrants have increased since the mid-1990s in Korea. Thus, their adaptation to Korean society has been a big social issue in Korea. There are a lot of academic researches on their adaptation to Korean society so far. We cannot sufficiently understand general main factors of their adaptation to Korean society because of methodological problems in the studies on the female marriage immigrants. Particularly, there are very few studies on female marriage immigrants' adaptation to their communities. This study analyzes determinants of female marriage immigrants' adaptation to their communities, using stepwise multi-regression. Data are collected from questionary survey on female marriage immigrants in Seoul, Gyeong-gi, Daegu, Gyeong-buk, Gwangju, Jeon-nam. Dependent variables are community life, spatial cognition and activities, and neighborhood relationship. Each dependent variable is analyzed with 30 independent variables through stepwise multi-regression. As a result, 16 positive determinants and 2 negative ones are selected. Positive determinants are resident identity, age, adaptation to home, number of Korean friends and same nationals' friends in Korea and so on. But, Korean language fluence is not selected as a significant factor. This is different from a general recognition. As exiting researches, the importance of social network and adaptation variables is also identified in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.622-626
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• 2007

Using multi-trait animal model BLUP, selection was conducted over seven generations for growth rate (DG), real-time ultrasound loin-eye muscle area (LEA), backfat thickness (BF), and intramuscular fat content (IMF) to develop a new line of purebred Duroc pigs with enhanced meat production and meat quality. This study was intended to investigate the relationship between restriction fragment length polymorphism (RFLP) of a heart fatty acid-binding protein (H-FABP) gene and intramuscular fat content (IMF) of this Duroc purebred population. The present experiment examined the RFLP of 499 slaughtered pigs. The DNA was separated from the blood or ear tissue of the pigs, which were slaughtered at 105 kg of body weight. Intramuscular fat content of the longissimus muscle was measured using chemical analysis. A significant difference was detected in the breeding value of IMF among the H-FABP PCR RFLP genotypes. The AA genotype has a significantly larger positive effect on the IMF breeding value than do the Aa and aa genotypes for the MspI RFLP. In addition, the DD genotype has a significantly greater positive effect on IMF breeding value than the Dd and dd genotypes for the HaeIII RFLP. For the HinfI RFLP, the hh genotype has a significantly larger positive effect on IMF breeding value than the HH genotype. Multiple regression analysis was performed using the IMF breeding values as the dependent variable and the three H-FABP genotypes as independent variables. Results revealed that the contribution of the genotypes to variation in IMF breeding values was approximately 40%. These results demonstrated that H-FABP RFLPs affect IMF in this Duroc population.

• Journal of Korean Academy of Nursing
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• v.47 no.1
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• pp.133-141
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• 2017

Purpose: The aim of this study was to identify the relationship between awareness of nutrition labeling and menstrual cycle irregularity in women from a nationally representative sample of the Korean population. Methods: A cross-sectional analysis was performed using hierarchical multi-variable logistic regression analysis models. A total of 4,324 women aged 19~54 years from the 2010~2012 Korean National Health and Nutrition Examination Survey participated in the study. The participants were classified into three groups based on self-report responses to a questionnaire about their awareness of nutrition labels: Reading, Not-Reading, and Not-Knowing Groups. Results: The Reading, Not-Reading, and Not-Knowing Groups comprised 46.4%, 44.9%, and 8.7% of the participants, respectively, and 53.6% of the participants had never used nutrition labels. In the Not-Knowing Group, irregular menstrual cycles for more than 3 months were significantly more common than women with irregular menstrual cycles for up to 3 months and women with regular menstrual cycles. Women in the Not-Knowing Group were more likely to exhibit menstrual cycle irregularity (adjusted odds ratio: 1.63, 95% confidence interval: 1.10~2.41) compared to women in the Reading Group after adjusting for age, body mass index, smoking status, alcohol intake, exercise regularity, stress, depression, suicidal ideation, metabolic syndrome, age at menarche, parity, and use of oral contraceptives. Conclusion: No awareness of nutrition labeling appears to be associated with a higher prevalence of menstrual cycle irregularity in a nationally representative group of Korean women.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.187-194
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• 2020

When a human being grew older, followed by visually and perceptually impaired, and dementia, it jeopardizes safety and life unless supportive design is secured for a living environment. This supportive space is based on universal design concept which offers safe-oriented, and simple use by incorporating gender and physical/mental limitation. The study of purppose was to examine the appropriateness of barrier-free standard for seniors' living in apartment through IPA. Chi-square analysis found that satisfaction with BF space is lowered as aging is continued and for female group. Regression analysis indicated that sink was the prime predictor in satisfaction, and stair/elevator was the most important variable. IPA concluded that sink, bath, shower/locker and alert/egress were prime BF indexes to be improved among 14 elements, implying careful design in sanitation area for seniors.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.30 no.2
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• pp.245-261
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• 2019

The purpose of this study was to investigate factors affecting the use of modern photographic records. Data was collected through a survey of 95 potential users for photographic records in future. Independent variables in this study included evidential value, informational value, usage value, intrinsic value. Dependent variable was selected as use intention for photographic records. The results of analysis of multi-regression analysis showed that evidential value and intrinsic value were found to have a positive impact on use intention for photographic records in modern korea. The results from this study can be used as important basic data for building archives for photographic record or for developing the policy for effective photographic records management.