• Title/Summary/Keyword: Model Equation

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Characteristics of Patients with Surgical Closure of an Atrial Septal Defect during Infancy

  • Byeong A Yoo;Su Jin Kwon;Yu-Mi Im;Dong-Hee Kim;Eun Seok Choi;Bo Sang Kwon;Chun Soo Park;Tae-Jin Yun
    • Journal of Chest Surgery
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    • v.56 no.3
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    • pp.155-161
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    • 2023
  • Background: Surgical closure of an atrial septal defect (ASD) is infrequently indicated during infancy. We evaluated the clinical characteristics and outcomes of patients who underwent surgical ASD closure during infancy. Methods: A single-center retrospective review was performed for 39 patients (19 males) who underwent surgical ASD closure during infancy between 1993 and 2020. The median body weight percentile at the time of operation was 9.3. Results: During a median follow-up of 60.9 months, 4 late deaths occurred due to chronic respiratory failure. A preoperative history of bronchopulmonary dysplasia (BPD) was the only risk factor for late mortality identified in Cox regression (hazard ratio, 3.54; 95% confidence interval [CI], 1.75-163.04; p=0.015). The 5-year survival rate was significantly lower in patients with preoperative history of BPD (97.0% vs. 50.0%, p<0.001) and preoperative ventilatory support (97.1% vs. 40.4%, p<0.001). There were significant postoperative increases in left ventricular end-diastolic (p=0.017), end-systolic (p=0.014), and stroke volume (p=0.013) indices. A generalized estimated equation model showed significantly better postoperative improvement in body weight percentiles in patients with lower weight percentiles at the time of operation (<10th percentile, p=0.01) and larger indexed ASD diameter (≥45 mm/m2, p=0.025). Conclusion: Patients with ASD necessitating surgical closure during infancy are extremely small preoperatively and remain small even after surgical closure. However, postoperative somatic growth was more prominent in smaller patients with larger defects, which may be attributable to an increase in postoperative cardiac output due to changes in ventricular septal configuration. The benefits of ASD closure in patients with BPD are undetermined.

A Study on the Mediating Effect of Motivation Factors between the Quality of Research Data Metadata and the Activation of Research Data Platform (연구데이터 메타데이터의 품질과 연구데이터플랫폼의 활성화의 관계에서 동기부여 요인의 매개효과 연구)

  • Seong-Eun Park
    • Journal of the Korean Society for Library and Information Science
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    • v.57 no.3
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    • pp.325-350
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    • 2023
  • This study focuses on the impact of research data metadata quality evaluation index on the revitalization of K-BDS, a research data platform in the bio field, and examines the mediating effect of motivation factors for utilizing the platform. The investigation employs a structural equation model analysis and bootstrap analysis to explore the interrelationships among the three variables. The findings demonstrate that researchers who prioritize the quality of metadata display higher motivation to use the research data platform, leading to an intention to activate the platform. The study also confirms the mediating effect of motivation factors. Moreover, a comprehensive understanding of the sub-factors within each variable is attained through regression analysis and Sobel test. The results highlight that enhancing searchability is crucial to activate research data sharing in the bio field, while improving discoverability is vital for research data reuse. Interestingly, the study reveals that citationability does not significantly impact platform activation. As a conclusion, to foster platform activation, it is imperative to provide systematic support by enhancing metadata quality. This improvement can not only increase trust in the platform but also institutionally solidify the benefits of citation.

The Effect of Smart Safety and Health Activities on Workers' Intended Behavior (스마트 안전보건활동이 근로자의 의도된 행동에 미치는 영향)

  • Choonhwan Cho
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.519-531
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    • 2023
  • With the aim of preventing safety accidents at construction sites, the company aims to create safe behaviors intended through variables called smart safety and health activities to help reduce industrial accidents. Purpose: It analyzes how smart safety and health activities affect accidents caused by unsafe behavior and changes in worker behavior, which is the root cause, and verifies the hypothesis that it helps prevent safety accidents and protect workers' lives. Method: Smart safety and health activities were selected as independent variables (X), and intended safety and anxiety, which are workers' behavioral intentions, were set as dependent variables (Y), attitude and subjective norms, and planned behavioral control as parameters (M). Exploratory factor analysis, discriminant validity analysis, and intensive validity analysis of safety and health activities were used to analyze the scale's reliability and validity. To verify the hypothesis of behavior change, the study was verified through Bayesian model analysis and MC simulation's probability density distribution. Result: It was found that workers who experienced smart safety and health activities at construction sites had the highest analysis of reducing unstable behavior and performing intended safety behavior. The research hypothesis that this will affect changes in worker behavior has been proven, the correlation between variables has been verified in the structural equation and path analysis of the research analysis, and it has been confirmed that smart safety and health activities can control and reduce worker instability. Conclusion: Smart safety and health activities are a very important item to prevent accidents and change workers' behavior at construction sites.

The Effect of Information Quality and Self-efficacy on Car-sharing Usage Intention (정보품질과 자기효능감이 카셰어링 재이용의도에 미치는 영향)

  • Liu, Bo;Byun, Sookeun
    • Journal of Service Research and Studies
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    • v.13 no.3
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    • pp.20-38
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    • 2023
  • Recently, car sharing has shown the most remarkable growth among sharing economy services. In the process of analyzing the intention to reuse the car sharing service, this study tried to reflect the unique characteristics of the service, which consists of non-face-to-face self-service, such as reservation, approval, handover, inspection, and return of the vehicle. Specifically, in addition to the perceived benefits and the perceived risks, we considered 'information quality' as a platform characteristic and 'self-efficacy' as a personal characteristic. To collect data, an online survey was conducted on adults with experience in car sharing, and a total of 320 responses were used for analysis. As a result of analyzing the structural equation model, it was found that information quality and self-efficacy increased the perceived benefits of services, and the higher the information quality, the higher the self-efficacy. On the other hand, the role of information quality and self-efficacy in lowering perceived risks was insignificant, and the intention to reuse services was more affected by perceived benefits than perceived risks. As a result of further analysis using Process Macro, it was found that the effect of self-efficacy on reuse intention was mediated by perceived benefits. It was analyzed that the indirect effects of information quality on reuse intention through perceived benefits or self-efficacy were all significant. These results suggest that providing timely, sufficient, and easy-to-understand information required by users on the platform improves self-efficacy and increases service reuse intention. In order to increase the number of service users, it is important for service providers not only to provide promotional activities such as offering attractive prices, but also to provide high-quality information so that users can use it more easily.

Disentangling Trade Effects of the Korea - China FTA: Trade Liberalization or Political Conflicts?

  • HuiHui Yin;Juyoung Cheong
    • Journal of Korea Trade
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    • v.27 no.3
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    • pp.21-42
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    • 2023
  • Purpose - This paper investigates the trade effect of the Korea-China Free Trade Agreement (KCFTA) which coincides with political conflicts between the two countries due to the deployment of the Terminal High Altitude Area Defense (THAAD) in Korea. The two events occurred in the same year and both are likely to affect trade between two countries but in opposite directions. Therefore, it is crucial to distinguish between the trade effects from the KCFTA event and those from the THAAD event to evaluate the true FTA effects. However, this would be difficult when using only annual data. Accordingly, ex post studies to examine the trade effects of KCFTA are lacking in trustworthiness while many ex ante studies that conjecture the positive trade effects neglect the THAAD deployment impact. This paper aims to fill that gap. Design/methodology - Given that the KCFTA and THAAD events occurred in the same year but in different months, we use the monthly data from 2000 to 2019 of Korea's exports to bracket this period. We employ the difference-in-difference (DID) method within a gravity equation specification that uses hi-dimensional fixed effects to address various endogeneity issues and seasonal effects. We identify the net impact of KCFTA ratification from these two near-simultaneous events to quantify the effects of trade liberalization between these two countries. Findings - After isolating the THAAD effects on trade, the analysis creates a positive and statistically significant coefficient estimate of the KCFTA impact. In contrast, failing to isolate the THAAD effect produced a negative and statistically significant coefficient estimate of the KCFTA impact. Our results indicate that KCFTA independently increased Korea's exports to China by 10.2%, but that this increase was fully mitigated by the THAAD event. Further, our results verify that unobserved heterogeneity and multilateral resistance are technically difficult to account for in those estimations as that rely solely upon annual data, as this type of data are inadequate to control for the potential for endogeneity. Originality/value - This paper is one of the first studies to carefully evaluate the net trade effects of the KCFTA on Korea's largest trading partner while isolating the impact of simultaneously occurred political events that may influence trade in opposing directions. Our findings indicate that the lack of prior evidence of positive trade effects of the KCFTA when using annual data may be attributed to a failure to identify the impact of each event separately. This analysis supports using the correct modeling specification to avoid misleading conclusions when evaluating any important international trade policy.

A Study on Social Issues and Consumption Behavior Using Big Data (빅데이터를 활용한 사회적 이슈와 소비행동 연구)

  • Baek, Seung-Heon;Kim, Gi-Tak
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.8
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    • pp.377-389
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    • 2019
  • This study conducted social network big data analysis to investigate consumer's perception of Japanese sporting goods related to Japanese boycott and to extract problems and variables by recognition. Social network big data analysis was conducted in two areas, "Japanese boycott" and "Japanese sporting goods". Months of data were collected and investigated. If you specify the research method, you will identify the issues of the times - keyword setting using social network analysis - clustering using CONCOR analysis using TEXTOM and Ucinet 6 programs - variable selection through expert meetings - questionnaire preparation and answering - and validity of questionnaire Reliability Verification - It consists of hypothesis verification using the structural model equation. Based on the results of using the big data of social networks, four variables of relevant characteristics, nationality, attitude, and consumption behavior were extracted. A total of 30 questions and 292 questionnaires were used for final hypothesis verification. As a result of the analysis, first, the boycott-related characteristics showed a positive relationship with nationality. Specifically, all of the characteristics related to boycotts (necessary boycott, sense of boycott, and perceived boycott benefits were positively related to nationality. In addition, nationality was found to have a positive relationship with consumption behavior.

Effects of Health-Related Food Labeling on Quality Assessment Before Purchase, Attitudes towards Using and Purchasing Products, and Purchase Intentions Based on the Theory of Planned Behavior (건강관련 식품표시가 구매 전 품질평가와 제품 사용 및 구매태도, 구매의도에 미치는 영향: 계획적 행동이론을 바탕으로)

  • Jun, Sangmin
    • Journal of Consumption Culture
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    • v.15 no.3
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    • pp.67-90
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    • 2012
  • When consumers choose healthy foods, they base their buying decisions on health-related food labeling and quality assessment of taste, health, and price. Moreover, both purchase experience and opinions of family and friends affect consumer choices. Focusing on these points, this study examined the effects of health-related food labeling on consumer choices by adding two variables-quality assessment of taste, health, and price and purchase experience-to the model of the theory of planned behavior. We also used structural equation modeling to test our hypotheses. In the study, health-related food labeling includes organic labeling, nutrient claims, and food additive labeling. We conducted a mail survey among 300 married women who buy cheese slices for their children more than once a month. It was discovered that health-related food labeling positively affected the level of quality assessment of taste, health, and price, and consequently led to positive attitudes and purchase intentions. Particularly, health-related food labeling positively influenced attitude toward using products without assessing the quality of taste, health, and price. The level of quality assessment of price positively affected attitude toward using and purchasing products, and purchase experience positively affected attitude toward using and purchasing products, and purchase intentions. The relationship between attitude to purchasing products and purchase intentions was the most positive, and the relationship between perceived behavioral control and purchase intentions was not significant. Overall, this study essentially contributes to the development of a theoretical framework of food labeling and consumer choices, which includes quality assessment of taste, health, and price and purchase experience, by using the theory of planned behavior.

The Effects of Community Participation Factors and Social Capital on Empowerment of Single Mother (한부모 여성의 공동체 참여요인과 사회자본이 임파워먼트에 미치는 영향에 관한 연구)

  • Lee, In-Sook
    • Korean Journal of Social Welfare Studies
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    • v.43 no.2
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    • pp.207-233
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    • 2012
  • The purpose of this study is to understand direct and indirect impact and the paths of community participation and social capital, which affect improvement of single mother's community participation factors, social capital, and empowerment. To accomplish this purpose structural relationships between single mother's community participation factors, social capital and empowerment have been analyzed. For the analysis 420 single mothers, who had participated various types of communities, were surveyed and structural equation modeling had been used and optical theory structure model(χ2=86.851, df=28, GFI=.958, CFI=.944), which explains the structural relationship among the factors, had been chosen. From the result, first, there was differences between empowerment and community participation levels, which is single mothers' community participation factors, of the impact on social capital and empowerment. Empowerment level of community, which was mediated by community participation level and social capital, affected empowerment, in the other hand, community participation level affected empowerment more directly than the impact of social capital. Second, single mothers' community participation factor affected more improvement of empowerment when it mediated by the accumulation of social capital. Third, single mothers' social capital directly affected the most improvement of empowerment. Based on the fact the implications of the study were presented.

Motion Vector Based Overlay Metrology Algorithm for Wafer Alignment (웨이퍼 정렬을 위한 움직임 벡터 기반의 오버레이 계측 알고리즘 )

  • Lee Hyun Chul;Woo Ho Sung
    • KIPS Transactions on Software and Data Engineering
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    • v.12 no.3
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    • pp.141-148
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    • 2023
  • Accurate overlay metrology is essential to achieve high yields of semiconductor products. Overlay metrology performance is greatly affected by overlay target design and measurement method. Therefore, in order to improve the performance of the overlay target, measurement methods applicable to various targets are required. In this study, we propose a new algorithm that can measure image-based overlay. The proposed measurement algorithm can estimate the sub-pixel position by using a motion vector. The motion vector may estimate the position of the sub-pixel unit by applying a quadratic equation model through polynomial expansion using pixels in the selected region. The measurement method using the motion vector can calculate the stacking error in all directions at once, unlike the existing correlation coefficient-based measurement method that calculates the stacking error on the X-axis and the Y-axis, respectively. Therefore, more accurate overlay measurement is possible by reflecting the relationship between the X-axis and the Y-axis. However, since the amount of computation is increased compared to the existing correlation coefficient-based algorithm, more computation time may be required. The purpose of this study is not to present an algorithm improved over the existing method, but to suggest a direction for a new measurement method. Through the experimental results, it was confirmed that measurement results similar to those of the existing method could be obtained.

Habitat Suitability Models of Endangered Wildlife Class II Mauremys reevesii in Gurye-gun, the Republic of Korea (전라남도 구례군에 서식하는 멸종위기 야생생물 II급 남생이의 서식지 적합성 모델 개발)

  • Chang-Deuk Park;Jeongwoo Yoo;Kwanik Kwon;Nakyung Yoo;Moon Seong Heo;Ju-Duk Yoon
    • Journal of Environmental Impact Assessment
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    • v.32 no.2
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    • pp.83-93
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    • 2023
  • This study was conducted to clarify the environmental variables that affect the appearance of Mauremys reevesii and to understand the relationship between M. reevesii and the variables. Habitat environmental survey was implemented by selecting 17 environmental variables considering ecological characteristics of M. reevesii in the main reservoir in Gurye-gun, the Republic of Korea. And the habitat data on the presence and absence of M.reevesii were analyzed statistically. The habitat suitability model of M. reevesii was described in following equation : logit (p) = -3.68 + (0.17 × leaf litter depth) + (1.55 × vegetation coverage of overstory on land) + (0.71 × coverage of midstory on land) + (0.96 × vegetation coverage of understory on water). This information gained is valuable for better understanding the distribution and how to conserve and promote populations of M. reevesii occurring in the Republic of Korea.