• Title/Summary/Keyword: Random Effects Model

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Flexural Strength of Composite HSB Girders in Positive Moment (HSB 강합성거더 정모멘트부의 휨저항강도)

  • Cho, Eun-Young;Shin, Dong-Ku
    • Journal of Korean Society of Steel Construction
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    • v.22 no.4
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    • pp.389-398
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    • 2010
  • The flexural strength of composite HSB I-girders under a positive moment was investigated using the moment-curvature analysis method to evaluate the applicability of the current AASHTO LRFD design specifications to such girders. A total of 2,391 composite I-girder sections that satisfied the section proportion limits of the AASHTO LRFD specifications was generated by the random sampling technique to consider a wide range of section properties. The flexural capacities of the sections were calculated inthe nonlinear moment-curvature analysis in which the HSB600 and HSB800 steels were modeled as an elasto-plastic strain-hardening material, and the concrete, as a CEB-FIP model. The effects of the ductility ratio and the compressive strength of the concrete slab on the flexural strength of the composite girders made of HSB and SM520-TMC steels were analyzed. The numerical results indicated that the current AASHTO LRFD equation can be used to calculate the flexural strength of composite girders made of HSB600 steel. In contrast, the current AASHTO LRFD equation was found to be non-conservative in its prediction of the flexural strength of composite HSB800 girders. Based on the numerical results of this study for 2,391 girders, a new design equation for the flexural strength of composite HSB800 girders in a positive moment was proposed.

Analysis of Repeated Measured VAS in a Clinical Trial for Evaluating a New NSAID with GEE Method (퇴행성 관절염 환자를 대상으로 새로운 진통제 평가를 위한 임상시험자료의 GEE 분석)

  • Lim, Hoi-Jeong;Kim, Yoon-I;Jung, Young-Bok;Seong, Sang-Cheol;Ahn, Jin-Hwan;Roh, Kwon-Jae;Kim, Jung-Man;Park, Byung-Joo
    • Journal of Preventive Medicine and Public Health
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    • v.37 no.4
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    • pp.381-389
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    • 2004
  • Objective : To compare the efficacy between SKI306X and Diclofenac by using generalized estimating equations (GEE) methodology in the analysis of correlated bivariate binary outcome data in Osteoarthritis (OA) diseases. Methods : A randomized, double-blind, active comparator-controlled, non-inferiority clinical trial was conducted at 5 institutions in Korea with the random assignment of 248 patients aged 35 to 75 years old with OA of the knee and clinical evidence of OA. Patients were enrolled in this study if they had at least moderate pain in the affected knee joint and a score larger than 35mm as assessed by VAS (Visual Analog Scale). The main exposure variable was treatment (SKI 306X vs. Diclofenac) and other covariates were age, sex, BMI, baseline VAS, center, operation history (Yes/No), NSAIDS (Y/N), acupuncture (Y/N), herbal medicine (Y/N), past history of musculoskeletal disease (Y/N), and previous therapy related with OA (Y/N). The main study outcome was the change of VAS pain scores from baseline to the 2nd and 4th weeks after treatment. Pain scores were obtained as baseline, 2nd and 4th weeks after treatment. We applied GEE approach with empirical covariance matrix and independent(or exchangeable) working correlation matrix to evaluate the relation of several risk factors to the change of VAS pain scores with correlated binary bivariate outcomes. Results : While baseline VAS, age, and acupuncture variables had protective effects for reducing the OA pain, its treatment (Joins/Diclofenac) was not statistically significant through GEE methodology (ITT:aOR=1.37, 95% CI=(0.8200, 2.26), PP:aOR=1.47, 95% CI=(0.73, 2.95)). The goodness-of-fit statistic for GEE (6.55, p=0.68) was computed to assess the adequacy of the fitted final model. Conclusions : Both ANCOVA and GEE methods yielded non statistical significance in the evaluation of non-inferiority of the efficacy between SKI306X and Diclofenac. While VAS outcome for each visit was applied in GEE, only VAS outcome for the fourth visit was applied in ANCOVA. So the GEE methodology is more accurate for the analysis of correlated outcomes.

Effect of Rehabilitation Intervention for Lifestyle Improvement of Spinal Cord Injury: Systematic Review of Randomized Controlled Trials and Meta-Analysis (척수 손상 환자의 라이프 스타일 개선을 위한 재활 중재 효과: 무작위 대조군 연구의 체계적 고찰 및 메타분석)

  • Ha, Sung Kyu;Park, Hae Yean
    • Therapeutic Science for Rehabilitation
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    • v.9 no.4
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    • pp.107-120
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    • 2020
  • Objective : The purpose of this study was to investigate the effectiveness and basis of rehabilitation intervention in patients with spinal cord injury by systematic review and meta-analysis of randomized controlled studies. Methods : Two researchers independently searched and selected a study published in an academic journal using a search term in an international thesis database. A total of 21 studies met the selection criteria, and qualitative evaluation of the study was conducted using the PEDro Scale. Meta-analysis was performed using Comprehensive Meta-Analysis 3.0 program. Results : A total of 713 subjects were included. The results of the meta-analysis showed a score of 0.406 (95.0% confidence interval: 0.221 ~ 0.591) for intervention using physical activity and 0.505 (95.0% confidence interval: 0.449 ~ 1.528) for electronic stimulation therapy, which showed medium effect; educational intervention had a 0.248 (95.0% confidence interval: 0.033 ~ 0.464), and mixed intervention 0.280 (95.0% confidence interval: 0.122 ~ 0.438). It was shown that the effect of small (small). There was a significant heterogeneity in the statistical heterogeneity test, and thus the random effects model was selected and analyzed. Conclusion : The results showed that rehabilitation interventions were effective for patients with spinal cord injury. During the rehabilitation of spinal cord injury patients, clinicians are expected to contribute to the development of programs to improve their lifestyles.

Comparison of Meta-analysis Results with and Without Adjustment for Healthy Worker Effect on the Association Between Occupational Exposure to Trichloroethylene and Cancer Risk (건강근로자효과 보정 전후의 메타 분석 결과 비교 -직업적 트리클로로에틸렌 노출과 암의 연관성-)

  • Park, Tae Won;Hwang, Sung Ho;Lee, Kyoung-Mu
    • Journal of Environmental Health Sciences
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    • v.40 no.5
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    • pp.385-396
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    • 2014
  • Objectives: By conducting a meta-analysis of cohort studies reporting standardized mortality ratios (SMRs) for workers exposed to trichloroethylene, we attempted to adjust for healthy hired effect by applying the same methods as described in a recent report from the Agricultural Health Study. Methods: Among all cohort studies that evaluated the association between all cancer, non-Hodgkin's lymphoma (NHL), kidney cancer, liver cancer and occupational exposure to trichloroethylene, a total of 10 studies reporting SMR values were selected. A random-effects model was used to estimate the summary SMRs or rSMRs and 95% confidence intervals. Relative SMR ($rSMR=SMR_x/SMR_{not\;x}$) was calculated comparing observed and expected counts for all cancer, NHL, kidney cancer, and liver cancer with an independent referent set of values consisting of the observed and expected counts for other causes. Results: The SMR values for all causes ranged from 0.68 to 1.03, suggesting moderate to weak healthy worker effect for the selected studies. When the healthy worker hire effect was taken into account, the summarized risk became statistically significant; the summary SMR of all cancer was 0.95 (0.91-1.00) and the summary rSMR of all cancer was 1.10 (1.04-1.15). The summary SMR of NHL was 1.04 (0.93-1.14) and the summary rSMR of NHL was 1.23 (1.04-1.46). The summary SMR of kidney cancer was 1.08 (0.88-1.33) and the summary rSMR of kidney cancer was 1.23 (1.02-1.49). The summary SMR of liver cancer was 0.88 (0.78-0.99), and the summary rSMR of liver cancer was 0.95 (0.84-1.07). Conclusion: The rSMR method is useful to determine summary risk adjusted for healthy worker effect through meta-analysis.

Structural relationship among servant leadership, empowerment and sports satisfaction of badminton coaches (배드민턴 지도자의 서번트 리더십과 임파워먼트 및 운동만족의 구조관계)

  • Lee, Mi-Sook;Nam, Jung-Hoon
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.2
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    • pp.317-331
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    • 2012
  • The purpose of this study was to verify the relationship among servant leadership, empowerment and sports satisfaction of badminton coaches by self-leadership. Among national badminton players, total 343 copies of data were collected and used at the study by using of random sampling. The normal distribution on data and the validity and reliability for each factors were proven to confirm through descriptive statistics, exploratory & confirmatory factor analysis and reliability analysis with SPSS 18.0 and AMOS 18.0 program. The relationship among each factors by the purpose of study were analyzed by correlation analysis and structural model analysis. The results were as follows. First, the servant leadership of badminton coaches had positive effect on empowerment. Second, the servant leadership of badminton coaches had positive effect on self-leadership. Third, the servant leadership of badminton coaches had positive effect on sports satisfaction. Fourth, empowerment had positive effect on sports satisfaction. Fifth, self-leadership had positive effect on sports satisfaction. Sixth, for the relationship between servant leadership and sports satisfaction, empowerment and self-leadership had indirect effects.

Effect of cassia cinnamon intake on improvement of the glycemic response: An updated meta-analysis - Focus on preparation of dehydrated powder and water extract (계피의 혈당 개선 기능성 평가 : 메타분석 - 건조분말과 물추출물을 중심으로)

  • Kwak, Jin Sook;Park, Min young;Kwon, Oran
    • Journal of Nutrition and Health
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    • v.50 no.5
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    • pp.437-446
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    • 2017
  • Purpose: This meta-analysis aimed to evaluate the effect of cassia cinnamon (Cinnamomum. cassia and C. aromaticum) on the glycemic response with a focus on the preparation of dehydrated powder and water extract. Methods: We searched Pubmed, Cochrane, EMBASE, Science Direct, and the Korean Studies Information Service System (KISS) through May 2017. In the meta-analysis for the preparation of powder, eight trials reporting fasting blood glucose (FBG), four trials reporting HbA1c, and three trials reporting the postprandial glycemic response were included. For the water extract, six trials reporting FBG and four trials reporting HbA1c were eligible for this study. A random-effects model was used to calculate the pooled effect size. Results: Cassia cinnamon powder intake significantly lowered FBG by -1.55 mmol/L (95% CI, -2.45, -0.64; p = 0.001) and the AUC of postprandial blood glucose level by $-51.8mmol/L{\cdot}min$ (95% CI, -85.5, -18.1; p = 0.003). There was a significant difference in FBG between water extract of cinnamon and placebo of -0.76 mmol/L (95% CI, -1.09, -0.43; p = 0.000). However, blood HbA1c level was not significantly altered by any preparation of cinnamon. No statistical heterogeneity was observed for any analysis except in the case of FBG for cinnamon powder. Results of funnel plots and Egger's regression suggest a low likelihood of publication bias in all biomarkers (p > 0.05). Conclusion: According to this meta-analysis, there was possible evidence to support a relationship between cassia cinnamon intake and fasting glucose in both preparation of powder and water extract. Furthermore, new evidence of the health benefits on postprandial glucose regulation of cinnamon powder was obtained.

Mediating Roles of Perceived Money Importance and Gratitude in the Effects of Social Support on Pleasure in Spending for Other-gift (사회적 지원과 돈의 중요성 및 고마움, 그리고 선물구매에서 지불의 기쁨)

  • Choi, Nak-Hwan
    • Journal of Distribution Science
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    • v.14 no.4
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    • pp.111-116
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    • 2016
  • Purpose - A lot of preceeding studies have focused on the pains that might be felt in spending money, that is an important role in getting psychological safety. Money and social resources can be all for consumers, and they are likely to form a substituting relationship with one another. Being motivated by the idea that spending money for others can come with joy if one's objective is accomplished by social support, this paper aimed to explore the mediating role of the perceived money importance and gratitude in the relationship between social support and pleasure in spending for other-gift. Research Design, Data, and Methodology - In this empirical study, the experimental group is expected to receive social support while the control group is composed of those who are usually indulged in reminiscences of their sweethearts. From the college students, 160 experiment participants were selected and 80 participants of them were assigned to control group as well as to experimental group respectively at random. Empirical study for each of the two groups was performed respectively by means of questionnaire survey. Experimental group data and control group data were combined together to be used for testing hypotheses. Linear structural equation model in Amos was used to verify the hypotheses, and Bootstrap was also used to examine whether there were the mediating roles of the perceived money importance and gratitude or not. Results - From the empirical study, following conclusions could be drawn: First, social support of others makes one perceive the importance of money less; Second, social support of others makes one perceive gratitude to others; Third, less perceived importance of money and gratitude to others can make one feel pleasure in spending for other-gift; and Fourth, less perceived importance of money and gratitude to others can partially mediate the effect of social support from others on the pleasure in spending for other-gift. Conclusions - The outcomes of this study might offer theoretic and managerial implications as follow: Even though many hitherto studies have asserted that spending money usually comes with pains, this study discovered that social support might reduce perceived the importance of money but make others feel gratitude and, thus, one would feel joy in spending money to buy gift for others, and made a contribution to the progress of the theory of pleasure in spending for other-gift. This paper also made contributions toward the development of emotion marketing theory by showing that the effect of social support on the pleasure in spending for other-gift could be partially mediated by the perceived the importance of money and gratitude to others. Based on the above conclusions, it may be affirmed that marketers should help consumers perceive the importance of money less, and help feel gratitude to others by pointing up the support of others to consumers in an attempt to accelerate spending for other-gift.

Factors Affecting Service Use Intention of Long-term Care among the Disabled: Focused on Age Differences of the Disabled (중고령 장애인의 장기요양서비스 이용의향 예측요인 연구: 중고령 장애인집단내 연령차이를 중심으로)

  • Moon, Yongpil
    • 한국사회정책
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    • v.25 no.1
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    • pp.125-159
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    • 2018
  • The purpose of this study is to analyze the factors affecting service use intention of long-term care among the disabled. This study conducts a longitudinal study using the modified Andersen model by the disabled age groups of the 50-64 group and the 65 over group. This study examined random effects panel logit analysis for the 50-64 group and the 65 over group by age variations. The results have shown that there are different factors Influencing factors for each specific age group of the disabled(50-64, 65 over). The results were as follows: there are differences of factors between the 50-64 group and the 65 over group. This study found that predisposing factors of the service use intention of long-term care were significantly related to age, residential area, education status, existence of spouses. Enabling factors of the service use intention of long-term care were significantly related to long-term care service recognition, saving, personal salary income level, housing status. Need factors of the service use intention of long-term care were significantly related to chronic diseases, psychological health, IADL. So, there are a need for a policy considerations such as service for the mid-old age disabled by age groups. Finally, implications and future research directions were discussed based on the finding of the study.

A Study on the Effect of Virtual Reality Intervention on Cognitive Function in Individuals With Stroke Through Meta-analysis (메타분석을 통한 뇌졸중 환자의 인지기능에 대한 가상현실 중재 효과 연구)

  • Kwon, Jae Sung
    • Therapeutic Science for Rehabilitation
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    • v.10 no.3
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    • pp.7-22
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    • 2021
  • Objective : The purpose of this study was to verify the effect of virtual reality interventions (VRIs) on cognitive function in individuals with stroke through a systematic literature review and meta-analysis. Methods : We reviewed randomized controlled trials (RCTs) the last 10 years using academic databases. PubMed, MEDLINE, and CINAHL were used for international studies, and DBpia, KISS, Kyoboscholar, and e-article were used for Korean studies. For the quantitative meta-analysis, subgroups of outcomes were classified into general cognitive function (G-CF), attention and memory (A&M), and executive function (EF). Results : Nine RCTs were analyzed. The total number of participants was 271 (140 in the experimental group). The effect size (Cohen's d) was estimated using a random effects model. The effect sizes of the outcome subgroups of were as follows: small to medium for G-CF (d=0.422; 95% CI: 0.101~0.742; p=0.010), small for A&M (d=0.249; 95% CI: -0.107~0.605; p=0.170), and medium for EF (d=0.666; 95% CI: 0.136~1.195; p=0.014). Conclusion : Considering the various stimuli provided by the virtual environment and the results from available research, virtual reality should be applied to interventions for integrated cognitive functions. In addition, it would be appropriate to be used as an additional intervention to traditional cognitive rehabilitation for stroke.

The Impact of Intellectual Properties on Foreign Direct Investment (지적재산권이 해외직접투자에 미치는 영향)

  • Kim, Seok-Chin;Yim, Jeong-Dae;Kang, Sang-Il
    • Korea Trade Review
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    • v.42 no.1
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    • pp.165-188
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    • 2017
  • Foreign direct investment is the means for companies to enter the overseas market and strengthen their competitiveness. The holding of intellectual properties, representing advantages of firms, may affect foreign direct investment. By expanding previous studies, we define intellectual properties as including trademarks and design as well as patents. Using a random-effect panel data model, we examine the effects of both intellectual properties of Korea and host countries on Korea's foreign direct investment in 128 countries from 1981 to 2014. The results are as follow. First, the coefficients of Korea's intellectual properties, patent, trademark, and design are significantly positive. This implies that Korean firms may invest abroad to take their advantages of technologies, brand value, and the capability of product differentiation. Second, except for patents, intellectual properties of host countries have a positive impact on foreign direct investment. In other words, foreign direct investment to acquire the ability of branding or product design from host countries may occur. Third, the coefficients of Korea's intellectual properties are significantly greater than those of host countries' properties. Foreign direct investment to take advantages of the firms' capabilities overseas is greater than one to acquire knowledge of host countries. Finally, Korea's intellectual properties have a greater positive impact on foreign direct investment in high growth countries than in low growth countries. It is interpreted that Korean firms are more motivated to exploit their intellectual properties in developing countries with a high growth than developed countries. Overall, it is confirmed that Korea's foreign direct investment not only to utilize some advantages but also to seek the brand value or product differentiation ability from host countries can occur. Our findings provide the contribution that some innovative activities in firms and R&D investments policies which encourage the possession of intellectual properties can improve foreign direct investment.

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