• Title/Summary/Keyword: meta-regression

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An Exploratory Meta Analysis of Library Economic Valuation Studies (도서관의 경제적 가치측정 연구의 탐색적 메타분석)

  • Chung, Hye-Kyung;Ko, Young-Man;Shim, Won-Sik;Pyo, Soon-Hee
    • Journal of the Korean Society for Library and Information Science
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    • v.43 no.4
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    • pp.117-137
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    • 2009
  • This study aims to grasp how to understand the difference in return on investment (ROI) or the cost-benefit ratio in forty-two domestic and overseas studies of library valuation, using a meta-analytical review method. Meta-analysis, a quantitative analysis on the findings of previous studies, was conducted to gather the general findings and lessons from prior empirical research. The results of meta-regression analysis indicate that the pattern of findings is consistent with our expectations regarding the effect of benefit scope and per capita GDP included in the ROI figure. This study appears to be the first meta-analytical review conducted on library valuations and the findings provide strong implications for the policy-making process.

Meta-analysis on the Effects of Fashion Product Evaluation Attributes in Korea (국내 연구의 패션상품 평가속성 효과에 대한 메타분석연구)

  • Lee, Jung-Woo;Kim, Mi Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.40 no.6
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    • pp.1150-1163
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    • 2016
  • This study makes use of meta-analysis to statistically integrate the quantitative results of individual research on the influence of fashion product attributes on purchase; in addition, this study utilizes the effect sizes of correlation coefficients. This study was based on 24 individual studies from January 2000 to March 2015. The meta-analysis analyzed 91 effect sizes and 24 studies and calculated the correlation coefficient effect sizes. A random effect model was employed for meta-analysis because the results for the homogeneity test indicated that the effect sizes of each research were heterogeneous. The analysis results are as follows. First, when the total effect sizes of the fashion product attributes that influence clothing purchase decisions were calculated as .256; this indicated that the effect size is slightly below the mid-sized level. Second, upon examining the effect sizes of the categorized fashion product attributes, the intrinsic attributes yielded .222, extrinsic factors yielded .235, and the compiled attributes yielded .420; this demonstrated that the compiled attributes have a larger effect size than individual attributes. Third, when they were measured by the characteristics of study targets, they were larger for a mixed-gender group than women as well as for ordinary citizens than university students. When the effect sizes were measured based on the characteristics of fashion products as suggested in the study, there were significant differences with respect to sportswear, followed by SPA brand clothing, general clothing, fashion accessories, and designer clothing. The cases where the clothing were purchased in non-retail stores were found to have a slightly larger effect size than those of offline retail stores when the effect sizes were measured based on purchase routes; however, the difference was not statistically significant. Next, an investigation of the trend of effect sizes based on published year via the meta regression analysis indicated slightly larger effect sizes as shown in more recent publications, but this was not statistically significant.

Factors Related to Positive Psychological Capital among Korean Clinical Nurses: A Systematic Review and Meta-Analysis (국내 임상간호사의 긍정심리자본 관련 요인: 체계적 문헌고찰 및 메타분석)

  • Lee, Byung Yup;Jung, Hyang Mi
    • Journal of Korean Clinical Nursing Research
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    • v.25 no.3
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    • pp.221-236
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    • 2019
  • Purpose: The purpose of this study was to systematically review and identify factors relevant to the positive psychological capital of clinical nurses. Methods: These was no limit on year of publication. Articles related to Korean clinical nurses were retrieved from computerized database using a manual search. A systematic review was conducted based on the PRISMA flow. The total correlational effect size (ESr) for each related factor was calculated from Fisher's Zr. Funnel plots, fail-safe numbers, and Egger regression tests were used to evaluate publication bias in meta-analysis studies. The correlational effect size of 25 studies was analyzed through meta-analysis using Comprehensive Meta-Analysis software 3.0 (CMA). Results: The review included 25 studies. In the systematic review, 14 demographic factors and 46 organizational factors were found to be influential. Eleven factors (6 demographic factors and 5 organizational factors) were appropriate for meta-analysis. The overall effect size was .26. The demographic total correlation effect size of related factors was .20 and the total effect size of organization was .46. Organizational commitment (ESr=.38) and job satisfaction (ESr=.54) were statistically positively related variables. Negative variables were burnout (ESr=-.61), turnover intention (ESr=-.41) and workplace bullying (ESr=-.33). The total effect size of the organizational factors was larger than the demographic total effect size. There was no publication bias except for demographic variables. Conclusion: Organizational factors and adjustable variables have a significant impact on positive psychological capital. The results of this study support the need for development of interventions focusing on organizational factors.

The Effects of Balloon-Guide Catheters on Outcomes after Mechanical Thrombectomy in Acute Ischemic Strokes : A Meta-Analysis

  • Ahn, Jun Hyong;Cho, Steve S.;Kim, Sung-Eun;Kim, Heung Cheol;Jeon, Jin Pyeong
    • Journal of Korean Neurosurgical Society
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    • v.62 no.4
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    • pp.389-397
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    • 2019
  • Objective : Mechanical thrombectomies with balloon-guide catheters (BGC) are thought to improve successful recanalization rates and to decrease the incidence of distal emboli compared to thrombectomies without BGC. We aimed to assess the effects of BGC on the outcomes of mechanical thrombectomy in acute ischemic strokes. Methods : Studies from PubMed, EMBASE, and the Cochrane library database from January 2010 to February 2018 were reviewed. Random effect model for meta-analysis was used. Analyses such as meta-regression and the "trim-and-fill" method were additionally carried out. Results : A total of seven articles involving 2223 patients were analyzed. Mechanical thrombectomy with BGC was associated with higher rates of successful recanalization (odds ratio [OR], 1.632; 95% confidence interval [CI], 1.293-2.059). BGC did not significantly decrease distal emboli, both before (OR, 0.404; 95% CI, 0.108-1.505) and after correcting for bias (adjusted OR, 1.165; 95% CI, 0.310-4.382). Good outcomes were observed more frequently in the BGC group (OR, 1.886; 95% CI, 1.564-2.273). Symptomatic intracranial hemorrhage and mortality did not differ significantly with BGC use. Conclusion : Our meta-analysis demonstrates that BGC enhance recanalization rates. However, BGC use did not decrease distal emboli after mechanical thrombectomies. This should be interpreted with caution due to possible publication bias and heterogeneity. Additional meta-analyses based on individual patient data are needed to clarify the role of BGC in mechanical thrombectomies.

Thermal Flow Analysis of an Engine Room using a Porous Media Model for Imitating Flow Rate Reduction at Outlet of Industrial Machines (다공성 매질 모델 기반 출구유량 감소 모사 기법을 이용한 산업기계용 엔진룸 열유동해석)

  • Choi, Yo Han;Yoo, Il Hoon;Lee, Chul-Hee
    • Journal of Drive and Control
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    • v.19 no.1
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    • pp.62-68
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    • 2022
  • Considering the characteristics of industrial machines that lack vehicle-induced wind, forced convection by a cooling fan is mostly required. Therefore, numerical analysis of an engine room is usually performed to examine the cooling performance in the room. However, most engine rooms consist of a number of parts and components at specific positions, leading to high costs for numerical modeling and simulation. In this paper, a new methodology for three-dimensional computer-assisted design simplification was proposed, especially for the pile of components and parts at the engine room outlet. A porous media model and regression analysis were used to derive a meta-model for imitating the flow rate reduction at the outlet by the pile. The results showed that the fitted model was reasonable considering the coefficient of determination. The final numerical model of the engine room was then used to simulate the velocity distribution by changing the mass flow rate at the outlet. The results showed that both velocity distributions were significantly changed in each case and the meta-model was valid in imitating the flow rate reduction by some piles of components and parts.

A Meta Analysis of the Effects of Physical Activity Programs in the Elderly with Disabilities (장애노인 신체활동 프로그램 효과에 대한 메타분석)

  • Kim, Kyungjin
    • Journal of the Korea Convergence Society
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    • v.9 no.7
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    • pp.301-308
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    • 2018
  • The study conducted a meta analysis to identify the effects of physical activity programs for the elderly with disabilities. The 14 out of 177 studies, fulfilled the process and requirement, were selected for the Hedges'g, funnel plot, forest plot, Egger's regression test, trim-and-fill, fail-safe N. There were three conclusions based on the results. First, the physical activity was effective for the elderly with disabilities and showed good effects on the psychomotor, cognitive, and affective domains. Second, the physical activity programs of fundamental exercise skill, game and sport, and fitness exercise showed positive effects on the psychomotor, cognitive, and affective domains in the elderly with disabilities. Third, the fundamental exercise skill for the psychomotor domain, the game and sport for the cognitive domain, and the fitness exercise for the affective domain were the most effective for the elderly with disabilities.

A Study on Generating Meta-Model to Calculate Weapon Effectiveness Index for a Direct Fire Weapon System (직사화기 무기체계의 무기효과지수 계산을 위한 메타모델 생성방법 연구)

  • Rhie, Ye Lim;Lee, Sangjin;Oh, Hyun-Shik
    • Journal of the Korea Society for Simulation
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    • v.30 no.2
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    • pp.23-31
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    • 2021
  • Defense M&S(Modeling & Simulation) requires weapon effectiveness index which indicates Ph(Probability of hit) and Pk(Probability of kill) values on various impact and environmental conditions. The index is usually produced by JMEM(Joint Munition Effectiveness Manual) development process, which calculates Pk based on the impact condition and circular error probable. This approach requires experts to manually adjust the index to consider the environmental factors such as terrain, atmosphere, and obstacles. To reduce expert's involvement, this paper proposes a meta-model based method to produce weapon effectiveness index. The method considers the effects of environmental factors during calculating a munition's trajectory by utilizing high-resolution weapon system models. Based on the result of Monte-Carlo simulation, logistic regression model and Gaussian Process Regression(GPR) model is respectively developed to predict Ph and Pk values of unobserved conditions. The suggested method will help M&S users to produce weapon effectiveness index more efficiently.

Effects of Cognitive Behavioral Therapy on Attention Deficit Hyperactivity Disorder among School-aged Children in Korea: A Meta-Analysis (한국 학령기 ADHD 아동을 위한 인지행동중재의 효과 연구: 메타분석)

  • Park, Wan-Ju;Park, Shin-Jeong;Hwang, Sung-Dong
    • Journal of Korean Academy of Nursing
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    • v.45 no.2
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    • pp.169-182
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    • 2015
  • Purpose: This study was a meta-analysis designed to identify effects of Cognitive Behavioral Therapy (CBT) interventions in alleviating main symptoms of Attention Deficit Hyperactivity Disorder (ADHD) among school-aged children in Korea. Methods: Examination of several databases including Research Information Sharing Service, Korean Studies Information Service System, Data Base Periodical Information Academic and hand-searched article references, resulted in identification of 1,298 studies done between 2000 and 2013 of which 21 met the inclusion criteria. Comprehensive Meta-Analysis version 2.0 was used to analyze effect sizes, explore possible causes of heterogeneity, and check publication bias with a funnel plot and its trim-and-fill analysis. Results: Overall effect size of CBT intervention was large (g=1.08) along with each outcome of self-control (g=1.26), lack of attention (g=1.02), social skills (g=0.92), and hyperactivity (g=0.92). For heterogeneity, moderator analysis was performed, but no significant differences were found between the RCT (Randomized Controlled Trials) group and the NRCT (Non RCT) group. Also, meta-regression was performed using sample size, number of sessions, and length of session as predictors, but no statistically significant moderators were found. Finally, a funnel plot along with trim-and-fill analysis was produced to check for publication bias, but no significant bias was detected. Conclusion: Based on these findings, there is clear evidence that CBT intervention has significant positive effects on the main symptoms of school-aged children suffering ADHD. Further research is needed to target diverse age groups with ADHD along with more RCT studies to improve the effectiveness of the CBT intervention.

Convergence Effect of Virtual Reality Program on Activities of Daily Living Ability in Stroke Patients : Meta-Analysis (가상현실 프로그램이 뇌졸중 환자의 일상생활활동 능력에 미치는 융합적 효과 : 메타분석)

  • Choi, Ki-Bok;Cho, Sung-Hyoun
    • Journal of the Korea Convergence Society
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    • v.11 no.8
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    • pp.63-70
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    • 2020
  • This study was designed to test the convergence effectiveness of virtual reality programs for patients with stroke by using meta-analysis. Based on the PICOS criteria, we searched domestic literature and selected the final 9 studies in relation to 'stroke' and 'virtual reality programs'. Evaluation of the risk of bias in individual studies was conducted using evaluation tools according to the design of each study. The effect size of the meta-analysis was calculated using CMA program. The mediating effect analysis was conducted by sub-group analysis and meta-regression analysis. The overall effect size of the virtual reality program on the activities of daily living ability was Hedges's g=0.302(95% CI: 0.064~0.540), Therefore, virtual reality programs can increase the activities of daily living in stroke patients and have a positive impact on the medical industry that the convergence of virtual reality industry and healthcare industry.

Circulating folate levels and colorectal adenoma: a case-control study and a meta-analysis

  • Park, Yeong Mi;Youn, Jiyoung;Cho, Chang Ho;Kim, Sung Hi;Lee, Jung Eun
    • Nutrition Research and Practice
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    • v.11 no.5
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    • pp.419-429
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    • 2017
  • BACKGROUND/OBJECTIVES: The relationship between folate and colorectal neoplasia remains controversial. We examined the association between serum folate concentrations and colorectal adenomas in a case-control study of Korean adults and conducted a meta-analysis. SUBJECTS/METHODS: Our case-control study included 113 pairs of case and control who underwent colonoscopy and provided blood samples. We used multivariable conditional logistic regression models to obtain the odds ratios and 95% confidence interval (CIs). For meta-analysis, we identified the relevant studies by searching the PubMed database up to February 2017, included our case-control study and combined the study-specific relative risks (RRs) using a random-effects model. RESULTS: In this case-control study, we included 58 men and 55 women with colorectal adenomas and sex and fasting status matched the controls. We did not find any significant association between the serum folate levels and colorectal adenomas in either men or women. For meta-analysis, a total of eleven studies were included in our analysis and classified into two groups; polyp clearance group (PC) for the studies that included participants who underwent endoscopies and had their polyps removed at baseline; and no polyp clearance group (NPC) for the studies that included participants whose histories of endoscopies were unknown or who underwent their first endoscopies. Four PC (1,311 cases and 1,672 non-cases) and eight NPC studies (3,501 cases and 11,347 non-cases) were included. The combined RRs (95% CIs) comparing the bottom with the top categories of circulating folate levels were 1.07 (0.97-1.18) for the NPC group but 1.45 (1.16-1.74) for the PC group. CONCLUSIONS: Low circulating folate levels were associated with new adenoma formation.