• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.10a
• /
• pp.289-290
• /
• 2022

Arteriosclerosis is a disease in which the carotid vessel wall becomes thick, and it is important to monitor the thickness of the vessel wall for diagnosis. In this study, we propose a model for extracting 324 radiomics features from carotid MRI images and diagnosing arteriosclerosis using machine learning techniques. We learned a total of four classification models: logistic regression, support vector machine, random forest, and XGBoost through radiomics features. XGBoost model, which showed the highest performance in 5-fold cross-validation, shows the results of accuracy 0.9023, sensitivity 0.9517, specificity 0.8035, AUC 0.8776.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.389-390
• /
• 2023

To improve the cost performance of construction sites, various systems and standards are constantly being developed and implemented. Although legal requirements for these system and standard improvements have been increasing, the cost efficiency performance of construction sites remains stagnant. We have digitized documents generated through construction supervision work at 39 building construction sites and proposed a model that can support decision-making in cost efficiency evaluation. This model selects key keywords that are considered to be highly related to cost efficiency by identifying the patterns and relationships of keywords through associated rule analysis and social network analysis using keywords derived from documents. In addition, it is expected to be used as a decision-making aid to determine the cost efficiency of a specific building construction site by establishing a logistic regression model using core keywords. As a systematic database of construction supervision documents and an integrated system of massive data generated by digital technology are established in the future, the accuracy and reliability of the cost efficiency evaluation model are expected to be reinforced.

• Journal of Distribution Science
• /
• v.21 no.10
• /
• pp.1-9
• /
• 2023

Purpose: This study analyses the current development of cross-border e-commerce in China, outlines the challenges faced by Chinese cross-border e-commerce SMEs, and finally summarises the development strategies of Chinese cross-border e-commerce SMEs in the post-covid-19 era, which will provide opinion references for the development of Chinese cross-border e-commerce SMEs. Research design, data and methodology: The methodology used in this study is to analyse the current situation of cross-border e-commerce development in China in the context of covid-19 through literature; and to summarise the challenges encountered by Chinese cross-border e-commerce SMEs through semi-structured interviews. Results: The article summarises the current status of China's cross-border e-commerce development in the context of covid-19 in terms of cross-border e-commerce trade volume, cross-border e-commerce enterprise and user scale, cross-border e-commerce logistics, cross-border e-commerce global co-operation, government policy, and cross-border e-commerce product distribution, outlining challenges encountered by China's cross-border e-commerce SMEs in terms of logistic pricing, operating capital chain, product service support, and trade protection The paper Finally, it is pointed out that Chinese cross-border e-commerce SMEs must adopt new strategies to adapt to the new development in the context of covid-19. Conclusions: Specific development strategies are provided for Chinese cross-border e-commerce enterprises and reference suggestions are provided for the post-covid-19 era.

• International conference on construction engineering and project management
• /
• 2011.02a
• /
• pp.534-541
• /
• 2011

Risk evaluation approaches for bidding on international construction projects are typically partitioned into three stages: country selection, project classification, and bid-cost evaluation. However, previous studies are frequently under attack in that they have several crucial limitations: 1) a dearth of studies about country selection risk tailored for the overseas construction market at a corporate level; 2) no consideration of uncertainties for input variable per se; 3) less probabilistic approaches in estimating a range of cost variance; and 4) less inclusion of covariance impacts. This study thus suggests a three-staged risk evaluation model to resolve these inherent problems. In the first stage, a country portfolio model that maximizes the expected construction market growth rate and profit rate while decreasing market uncertainty is formulated using multi-objective genetic analysis. Following this, probabilistic approaches for screening bad projects are suggested through applying various data mining methods such as discriminant logistic regression, neural network, C5.0, and support vector machine. For the last stage, the cost overrun prediction model is simulated for determining a reasonable bid cost, while considering non-parametric distribution, effects of systematic risks, and the firm's specific capability accrued in a given country. Through the three consecutive models, this study verifies that international construction risk can be allocated, reduced, and projected to some degree, thereby contributing to sustaining stable profits and revenues in both the short-term and the long-term perspective.

• Asia pacific journal of information systems
• /
• v.29 no.3
• /
• pp.382-406
• /
• 2019

We study the antecedents to tie formation on an (Facebook-like) enterprise social media platform implemented to support cross-boundary connections. Research has produced mixed findings regarding the role of social media in cultivating bridging vs. closed networks. We examine the tie formation patterns of 1,386 enterprise social media users over a two-year period. Specifically, we observe who became (or chose not s become) "friends" with whom at the dyadic level and relate the decisions to various mechanisms that affect one's network to expand, constrain, or bridge. Using logistic and OLS regressions, we find that users tend to form ties via reciprocity and transitivity (with friends of friends), both of which help expand one's network. We also find strong networking tendency toward functional and hierarchical homophily (same business unit and same rank, respectively), which is likely to constrain one's network (closed network structure). We find that one's participation in various online interest groups is likely to open one's network (bridging network structure) while no evidence found for preferential attachment. Overall, we find that enterprise social media offers features, some of which are likely to foster bridging while others foster closed networks via different mechanisms.

• ETRI Journal
• /
• v.46 no.4
• /
• pp.648-659
• /
• 2024

Author verification is challenging because of the diversity in writing styles. We propose an enhanced handwriting verification method that combines handcrafted and automatically extracted features. The method uses a genetic algorithm to reduce the dimensionality of the feature set. We consider offline Bangla handwriting content and evaluate the proposed method using handcrafted features with a simple logistic regression, radial basis function network, and sequential minimal optimization as well as automatically extracted features using a convolutional neural network. The handcrafted features outperform the automatically extracted ones, achieving an average verification accuracy of 94.54% for 100 writers. The handcrafted features include Radon transform, histogram of oriented gradients, local phase quantization, and local binary patterns from interwriter and intrawriter content. The genetic algorithm reduces the feature dimensionality and selects salient features using a support vector machine. The top five experimental results are obtained from the optimal feature set selected using a consensus strategy. Comparisons with other methods and features confirm the satisfactory results.

• The Journal of Economics, Marketing and Management
• /
• v.12 no.5
• /
• pp.31-40
• /
• 2024

Purpose: This study analyzes the factors influencing the housing preferences of elderly individuals when choosing residential areas in Hwaseong, a typical urban-rural complex city. Understanding these preferences is vital for formulating effective housing policies that enhance the quality of older people's life. Research design, data, and methodology: The survey conducted from March 10 to April 10, 2024, targeted 299 pre-retirees aged 50-64 living in Hwaseong. Using ANOVA and logistic regression analysis, the study examined essential factors affecting post-retirement residential decisions. Survey questions addressed essential considerations. Results: The results indicated that suburban housing was the most preferred option among pre-retirees in Hwaseong. The most critical factor that influences the choice of the home is ensuring convenience and relaxed in retirement. Significant differences emerged between housing type preferences, particularly in the importance of public transportation, cultural facilities, and housing prices. Conclusions: The study suggests several policy implications for urban-rural complex cities like Hwaseong. To meet the diverse needs of older people, urban housing should focus on improving accessibility, while rural housing should emphasize enhancing natural environments. Expanding rental housing options for older people and providing financial support for housing prices are recommended to promote housing stability for the aging population.

• Journal of agricultural medicine and community health
• /
• v.34 no.1
• /
• pp.13-23
• /
• 2009

Objective: The objective of this study was to evaluate the association of social support with health status and health behavior. Methods:　This study was conducted with 79 elderly people in Gunja-ri, Dongsan-myun, Chuncheon. We performed face to face interview which was composed of socio-demographic characteristics, social support, health status and health behavior. The association between social support and result variables was analysed by Chi-square test and logistic regression. We used SAS ver9.1 for statistic analysis. Results: Mean age of the study population was 72.0$\pm$7.0, social support score was 14.3$\pm$4.7 with full marks of 20 and 36.25% of the total population were shown to have depression. When the social support score was changed, depression (p=0.0007) and physical exercise (p=0.0312) showed significant difference. The self-rated health status was significantly related to the relationship with family members (OR=0.25, 95% CI=0.07-0.95) and the quality of sleep was also significantly associated to the relationship with family members (OR=0.21, 95% CI=0.06-0.73). The physical exercise was done significantly less in the group without close friends than in the group with many close friends (OR=0.21, 95% CI=0.05-0.94) and the depression was significantly more in the group without community participation than in the group with community participation (OR=4.79, 95% CI=1.62-14.15). Conclusions: Through this study, we could conclude that the social support factors are associated with health status and health behavior. Therefore, to improve the health status of rural elderly, we need to approach to develop social support.

• Journal of dental hygiene science
• /
• v.17 no.2
• /
• pp.134-141
• /
• 2017

This study examined 191 pregnant women before delivery in an obstetrics and gynecology clinic in North Gyeongsang Province from May to September 2016 by using a questionnaire after obtaining informed consent for voluntary participation in the study. The study was performed to investigate the association of depression with sociodemographic characteristics, pregnancy-related characteristics, social support, sleep quality and Oral Health Impact Profile (OHIP) in pregnant women. The prevalence of depression among the pregnant women was 25.1% in the healthy group and 74.9% in the depression group. The depression level was significantly higher in women in the depression group who were unsatisfied with their marriage life, had no occupation, had lower social support, had poor sleep quality and had higher OHIP scores. The results of the logistic regression analysis indicated that, the risk ratio for more severe depression was significantly higher in the group with no experience of miscarriage and induced childbirth than in the group with childbirth experience. Conversely, the risk ratio for more severe depression was significantly lower in the group with high social support than in the group with low social support. Depression in the respondents significantly positively correlated with sleep quality and OHIP score but significantly negatively correlated with social support. The multiple regression analysis revealed that the depression level was significantly higher by 22.3% among pregnant women with lower marital satisfaction, no childbirth experience, lower social support and higher OHIP scores. In summary, depression was related to marital satisfaction, childbirth experience, social support, and OHIP score, among others, in pregnant women in this study. Therefore, further investigation is warranted to construct programs and measures that will help build positive thinking by designing and verifying a three-dimensional study model by taking into consideration various variables to reduce the incidence of depression in pregnant women.

• 한국노년학
• /
• v.40 no.4
• /
• pp.707-727
• /
• 2020

This study aims to empirically analyze the role that perception of the probability of lonely death among the elderly people living alone plays in the relationship between perceived social support and preference for institutional care based on Andersen's expanded Behavioral Model (2002). The subjects (n=676) of this study were the elderly people living alone, extracted from the "2018 Seoul Aging Survey." With "perceived social support" as an independent variable, "preference for institutional care" as a dependent variable, and "perception of the probability of lonely death" as a mediator variable, we conducted a Binary Logistic Regression to follow the three steps of analyzing mediation effect, as suggested by Baron and Kenny (1986). The results showed that perceived social support has a negative effect on the preference for institutional care and perception of the probability of lonely death among the elderly people living alone; at the same time, perception of the probability of lonely death was found to have a positive effect on their preference for institutional care. Lastly, perception of the probability of lonely death was found to partially mediate the effect of perceived social support among the elderly people living alone in terms of their preference for institutional care. Based on these findings, the practical implications of this study can be summarized as follows. First, various programs and support should be provided to the elderly people living alone in order to enhance the level of perceived social support, a factor that has been confirmed to increase preference for institutional care among the elderly people living alone. Second, as the perception of the probability of lonely death was confirmed to be a psychosocial factor of the preference for institutional care, we need to promote education and support for older people living alone to prepare them for lonely death. These efforts are expected to form a foundations for implementing a community-based integrated care system, "Aging in Place," which is the policy direction required for older people care.