• Genomics & Informatics
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• v.19 no.1
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• pp.11.1-11.8
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• 2021

For the novel coronavirus disease 2019 (COVID-19), predictive modeling, in the literature, uses broadly susceptible exposed infected recoverd (SEIR)/SIR, agent-based, curve-fitting models. Governments and legislative bodies rely on insights from prediction models to suggest new policies and to assess the effectiveness of enforced policies. Therefore, access to accurate outbreak prediction models is essential to obtain insights into the likely spread and consequences of infectious diseases. The objective of this study is to predict the future COVID-19 situation of Korea. Here, we employed 5 models for this analysis; SEIR, local linear regression (LLR), negative binomial (NB) regression, segment Poisson, deep-learning based long short-term memory models (LSTM) and tree based gradient boosting machine (GBM). After prediction, model performance comparison was evelauated using relative mean squared errors (RMSE) for two sets of train (January 20, 2020-December 31, 2020 and January 20, 2020-January 31, 2021) and testing data (January 1, 2021-February 28, 2021 and February 1, 2021-February 28, 2021) . Except for segmented Poisson model, the other models predicted a decline in the daily confirmed cases in the country for the coming future. RMSE values' comparison showed that LLR, GBM, SEIR, NB, and LSTM respectively, performed well in the forecasting of the pandemic situation of the country. A good understanding of the epidemic dynamics would greatly enhance the control and prevention of COVID-19 and other infectious diseases. Therefore, with increasing daily confirmed cases since this year, these results could help in the pandemic response by informing decisions about planning, resource allocation, and decision concerning social distancing policies.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1021-1033
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• 2021

Objective: To assess the expression of vascular normalization genes in different molecular subtypes of breast cancer and to determine whether molecular subtypes with a higher vascular normalization gene expression can be identified using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI). Materials and Methods: This prospective study evaluated 306 female (mean age ± standard deviation, 50 ± 10 years), recruited between January 2014 and August 2017, who had de novo breast cancer larger than 1 cm in diameter (308 tumors). DCE MRI followed by IVIM DWI studies using 11 different b-values (0 to 1200 s/mm²) were performed on a 1.5T MRI system. The Tofts model and segmented biexponential IVIM analysis were used. For each tumor, the molecular subtype (according to six [I-VI] subtypes and PAM50 subtypes), expression profile of genes for vascular normalization, pericytes, and normal vascular signatures were determined using freshly frozen tissue. Statistical associations between imaging parameters and molecular subtypes were examined using logistic regression or linear regression with a significance level of p = 0.05. Results: Breast cancer subtypes III and VI and PAM50 subtypes luminal A and normal-like exhibited a higher expression of genes for vascular normalization, pericyte markers, and normal vessel function signature (p < 0.001 for all) compared to other subtypes. Subtypes III and VI and PAM50 subtypes luminal A and normal-like, versus the remaining subtypes, showed significant associations with K^trans, k_ep, v_p, and IAUGC_BN90 on DEC MRI, with relatively smaller values in the former. The subtype grouping was significantly associated with D, with relatively less restricted diffusion in subtypes III and VI and PAM50 subtypes luminal A and normal-like. Conclusion: DCE MRI and IVIM parameters may identify molecular subtypes of breast cancers with a different vascular normalization gene expression.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3302-3307
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• 2009

The objective of the present study lies in providing the method to construct the precision population-statistical map for statistical demographics making full advantage of GIS and the national census data in an attempt to improve accuracy and reliability of population estimation applicable for a variety of location analysis. More specifically, it adopts the multiple regression analysis by segmented land use type(biotope) taking into account that the land use diversified as residence, commercial and office areas has the close connectivity and interdependence with population. Based on the analyzed result above, the study finalizes the modeling to construct demographic map with higher precision by prioritizing the population density by weight value and then re-distributing the population according to jurisdictional dong's and types of use for the land. The study consequently is expected to be conducive to improving precision and reliability rather than the existing method for population estimation widely acceptable thus far.

• Korean journal of food and cookery science
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• v.30 no.1
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• pp.84-91
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• 2014

The purpose of this study was to identify the effects of emotional labor on emotional exhaustion among school dietitians according to the level of their self-efficacy. A survey was administered on 300 school dietitians during September 2012 and a total of 277 usable questionnaires were received. The data were analyzed by using the SPSS 18.0 package program. As a result of principal factor analysis for validity test, 26 variables were classified into one factor for self-efficacy, three factors for emotional labor and one factor for emotional exhaustion with a total variance percentage of 67.371%. Internal consistency was estimated by Cronbach's alpha, which yielded reliability coefficients of 0.922 (self-efficacy), 0.916 (emotional display), 0.806 (surface acting), 0.808 (deep acting) and 0.850 (emotional exhaustion). Subjects were segmented into 2 groups of 'high self-efficacy' (n = 159) and 'low self-efficacy' (n = 118) according to the cluster analysis for self-efficacy variables. The 'high self-efficacy' group exhibited higher education(p < 0.01) and served less lunch meals than other groups (p < 0.05). According to multiple regression analysis, the emotional display proved to be significantly and positively related to emotional exhaustion (${\beta}$=0.319, p<0.001) in high self-efficacy group. However both emotional display (${\beta}$=0.233, p<0.05) and surface acting (${\beta}$=0.262, p<0.01) were positively related to emotional exhaustion in the low self-efficacy group. These results suggest that school dietitians should be more aware of their self-efficacy to relieve the effects of the emotional labor on emotional exhaustion.

• The Research Journal of the Costume Culture
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• v.19 no.3
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• pp.637-649
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• 2011

Environmental protection has become more important than ever because of increasing environmental pollution and abnormal climatic changes caused by the depletion of resources from industrial activities. Fashion products can create various environmental pollutants during the production process. Since they are in direct contact with the body, the environment-friendly features for the fashion industry will become increasingly important and the necessity to execute a detailed study regarding the environment-friendly fashion marketing will also become increasingly important. The purpose of this study was to segment the levels of environment-friendly fashion marketing mixes, that analyze the relationship between consumer decision-making factors and purchasing intentions. We propose effective several marketing strategies. A total of 457 questionnaires were analyzed using frequency analysis, t-tests, correlation analysis, regression analysis, and ANOVA in SPSS. The results are as follows: First, environment-friendly fashion products were segmented into four groups, environment-friendly materials, environment-friendly production, environment-friendly management, and recycling/ disuse of products. Second, the promotion of environment-friendly fashion products were highly ranked, followed by materials used, distribution methods, and production management. Third, women considered usage, management, and price for environment-friendly fashion products as more important than men did. Finally, a total of 39.4% of the respondents had purchased environment-friendly fashion products, with a preference to buy environment-friendly underwear, outerwear, bags, shoes, and accessories. By establishing and executing the environment-friendly fashion marketing mixes, fashion companies execute successful marketing activities in both domestic and international markets.

• The Korean Journal of Community Living Science
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• v.21 no.4
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• pp.619-631
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• 2010

The purpose of this study is to segment and examine urban farmers behavior by applying a two-step cluster analysis and multi-nominal logit model. The data were collected by a telephone survey with two-staged stratified random sampling in the cities around the country for the purpose of acquiring representative data. Respondents were asked to describe their awareness of urban agriculture, their agricultural activity, and sociodemographic characteristics. Among 2,000 cases, 381 cases(19.1%) which were of participants in urban agriculture were analysed in SPSS. From the findings, 27.3% of respondents had heard the word 'urban agriculture', and 25.5% of them regarded themselves as urban farmers. Four different clusters were derived from two-step clusters based on motive, place, companion, area and hours. They were 'Large scale hobby farming(cluster 1)', ‘Weekend farm/ hobby farming(cluster 2)', 'Land/ Self-supporting farming(cluster 3)', and 'Small scale hobby farming(cluster 4)'. The result of multinomial logistic regression showed that there were significant differences among these four segmented groups in terms of age, city size and housing type. In other words, there is quite a possibility that urbanites select different urban farming types according to their socio-demographic profiles. Therefore, the urbanite profiles can be used as the basis for promoting policy of several urban agriculture types. According to the result, policy directions for facilitating urban agriculture were presented.

• Journal of the Korean Home Economics Association
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• v.44 no.3 s.217
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• pp.27-49
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• 2006

This study investigated the integrated effects of family, school, internet, and mass culture factors on the identity formation of adolescents. Specifically, the purposes of this study were to categorize adolescents into groups by what they do during the time except the life in school and to investigate differences among the groups regarding the identity information(body image, self-esteem, self-identity) and the influences of environmental factors on identity formation of adolescent. The study distributed questionnaires to middle and high school adolescents of five representative cities in South Korea. The total respondents were 2240(960 from Seoul/Kyongki, and 320 each from Taegu, Pusan, Kwangju, and Taejon). The response rate was 98.7%. The data were analyzed by factor analysis, cluster analysis, ANOVA, Duncan test, and multiple regression. The results showed that Korean adolescents were segmented into five groups : TV preference group, computer preference group, friends and family involvement group, homework and study preference group, and study institute involvement group). The five groups were significantly different in regard to body image pursuit, self-esteem, and self-identity. The body image pursuit, self-esteem, and self-identity of adolescents were significantly different in regard to each environmental factors, in each adolescent group.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1138-1148
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• 2010

This study examines the characteristics of the online child-rearing community launched by the voluntary motivations of consumers, and the effects of those characteristics on community loyalty and the intentions to buy baby wear via community sites. The study was implemented by a descriptive survey method using an online questionnaire. The sample consisted of 212 members of online child-rearing communities. The data were analyzed by frequency, factor analysis, and regression analysis. Results are as follows. 1) It was found that there were four major factors of online child-rearing community characteristics, such as attachment/pleasure, practical/economy, interaction, and information. 2) All four factors had significant effects on community loyalty. 3) The factor attachment/pleasure had no significant effects on intentions to buy baby wear, but practical/economy, interaction and information had effects upon those intentions. 4) Loyalty to the online child-rearing community had significant effects on the intentions of community members to buy baby wear via the community site. In addition, online child-rearing community members are interested in information regarding baby wear as well as its purchase; this is why baby wear makers should perform cost efficient consumer group segmentation in a timely manner. In addition, it will be effective for their marketing activities to target such consumer groups as segmented.

• Journal of Korean Medical Science
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• v.33 no.51
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• pp.328.1-328.12
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• 2018

Background: In cardiac arrest, the survival rate increases with the provision of bystander cardiopulmonary resuscitation (CPR), of which the initial response and treatment are critical. Telephone CPR is among the effective methods that might increase the provision of bystander CPR. This study aimed to describe and examine the improvement of neurological outcomes in individuals with out-of-hospital acute cardiac arrest by implementing the nationwide, standardized telephone CPR program. Methods: Data from the emergency medical service-based cardiac arrest registry that were collected between 2009 and 2014 were used. The effectiveness of the intervention in the interrupted time-series study was determined via a segmented regression analysis, which showed the risk ratio and risk difference in good neurological outcomes before and after the intervention. Results: Of 164,221 patients, 148,403 were analyzed. However, patients with unknown sex and limited data on treatment outcomes were excluded. Approximately 64.3% patients were men, with an average age of 63.7 years. The number of bystander CPR increased by 3.3 times (95% confidence interval [CI], 3.1-3.5) after the intervention, whereas the rate of good neurological outcomes increased by 2.6 times (95% CI, 2.3-2.9 [1.6%]; 1.4-1.7). The excess number was identified based on the differences between the observed and predicted trends. In total, 2,127 cases of out-of-hospital cardiac arrest (OHCA) after the intervention period received additional bystander CPR, and 339 cases of OHCA had good neurological outcomes. Conclusion: The nationwide implementation of the standardized telephone CPR program increased the number of bystander CPR and improved good neurological outcomes.

• Health Policy and Management
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• v.32 no.4
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• pp.389-399
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• 2022

Background: This study aimed to analyze changes in medical utilization and cost before and after long-term care (LTC) implementation. Methods: We used the National Health Information Database from National Health Insurance Service. The participants were selected who had a new LTC grade (grade 1-5) for 2015. Medical utilization was analyzed before and after LTC implementation. Segmented regression analysis of interrupted time series was conducted to evaluate the overall effect of the LTC implementation on medical costs. Results: The total number of participants was 41,726. A major reason for hospitalization in grade 1 was cerebrovascular diseases, and dementia was the top priority in grade 5. The proportion of hospitalization in grade 1 increased sharply before LTC implementation and then decreased. In grade 5, it increased before LTC implementation, but there was no significant difference after LTC implementation. As for medical cost, in grades 1 to 4, the total cost increased sharply before the LTC implementation, but thereafter, changes in level and trend tended to decrease statistically, and for grade 5, immediately after LTC implementation, the level change was decreasing, but thereafter, the trend change was increasing. Conclusion: Long-term care grades showed different medical utilization and cost changes. Long-term care beneficiaries would improve their quality of life by adequately resolving their medical needs by their grades.