• Title/Summary/Keyword: Random Effects Model

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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.

Estimating uncertainty in limit state capacities for reinforced concrete frame structures through pushover analysis

  • Yu, Xiaohui;Lu, Dagang;Li, Bing
    • Earthquakes and Structures
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    • v.10 no.1
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    • pp.141-161
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    • 2016
  • In seismic fragility and risk analysis, the definition of structural limit state (LS) capacities is of crucial importance. Traditionally, LS capacities are defined according to design code provisions or using deterministic pushover analysis without considering the inherent randomness of structural parameters. To assess the effects of structural randomness on LS capacities, ten structural parameters that include material strengths and gravity loads are considered as random variables, and a probabilistic pushover method based on a correlation-controlled Latin hypercube sampling technique is used to estimate the uncertainties in LS capacities for four typical reinforced concrete frame buildings. A series of ten LSs are identified from the pushover curves based on the design-code-given thresholds and the available damage-controlled criteria. The obtained LS capacities are further represented by a lognormal model with the median $m_C$ and the dispersion ${\beta}_C$. The results show that structural uncertainties have limited influence on $m_C$ for the LSs other than that near collapse. The commonly used assumption of ${\beta}_C$ between 0.25 and 0.30 overestimates the uncertainties in LS capacities for each individual building, but they are suitable for a building group with moderate damages. A low uncertainty as ${\beta}_C=0.1{\sim}0.15$ is adequate for the LSs associated with slight damages of structures, while a large uncertainty as ${\beta}_C=0.40{\sim}0.45$ is suggested for the LSs near collapse.

Age-related Bimanual Coordination Impairments in Elderly People: a Systematic Review and Meta-analysis (건강한 노인의 양손 협응성 변화 패턴: 체계적 문헌고찰 및 메타분석 연구)

  • Kim, Rye Kyeong;Kang, Nyeonju
    • Korean Journal of Applied Biomechanics
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    • v.31 no.4
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    • pp.259-269
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    • 2021
  • Objective: The purpose of this systematic review and meta-analysis was to investigate age-related bimanual coordination functions in older adults. Method: Thirteen studies that compared bimanual coordination functions in older adults with those in healthy young adults qualified for this meta-analysis. We additionally categorized 21 total comparisons from the 13 qualified studies into two types of task-related moderator variables: (1) kinematic versus kinetic movements and (2) symmetry versus asymmetry movements. Results: Random effects model meta-analysis found that older adults revealed significant bimanual coordination impairments as compared with young adults (Hedges's g = -0.771; p < .0001; I2 = 74.437%). We additionally confirmed specific bimanual coordination deficits using two moderator variables: 1) kinematic (Hedges's g = -0.884; p < .0001; I2 = 0.000%) and kinetic (Hedges's g = -0.666; p = .023; I2 = 86.170%). 2) symmetry (Hedges's g = -0.712; p = .001; I2 = 74.291%) and asymmetry (Hedges's g = -0.817; p < .0001; I2 = 76.322%). The moderator variable analysis indicated older adults indicated bimanual coordination deficits in the upper extremities than healthy young adults while performing kinematic bimanual coordination tasks and asymmetry coordination tasks. Conclusion: These findings suggest that developing motor rehabilitation programs based on asymmetric bimanual movement task for enhancing interlimb coordination functions of older adults may be crucial for increasing their independence in everyday activities. Given that elderly revealed the deficits in lower extremities coordination when older adults perform gait, posture, and balance, future studies should estimate lower limb coordination functions in elderly people.

The Effect of Manual Physical Therapy on Improvement in the Range of Motion of Frozen Shoulder Patients: A Meta-Analysis of Cases in South Korea

  • Kim, Chan Myeong;Lee, Jong Kyung;Hwang, Jong Ha;Lee, Jae Kwang
    • The Journal of Korean Physical Therapy
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    • v.33 no.5
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    • pp.211-216
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    • 2021
  • Purpose: The main purpose of this meta-analysis was to identify the degree of effect size and variables for the impact of manual physical therapy on the improvement in the range of motion of frozen shoulder patients. Methods: This study collected 8 studies published between 1st January 2010 and 31st December 2020. The analysis of the results verified 49 effect size data and the random effect model was chosen. Results: First, the full case showed the largest mean effect size of 2.485 (p<0.001). Second, the size of the effect based on manual therapy and modality therapy showed an effect size of 4.178 (p<0.001). Third, the outcome group included 6 variables. The external rotation (2.818) variable group showed the largest mean effect size, followed by internal rotation (2.748), flexion (2.643), abduction (2.356), and adduction (2.356). Six outcomes were significant and the mean effect sizes of all the varied groups were above large size. The number of participants showed a 20 or less effect size of 2.478 (p>0.737). The number of intervention periods showed 4 weeks 20 or more effect size of 2.782 (p>0.294). Finally, the 'Trim and Fill' result confirmed that the calibration effect size was 1.471 (p<0.001). Conclusion: This study verified that manual physical therapy had a substantial effect on the improvement of the range of motion of patients with frozen shoulders and that the effects were dependent on the methods of outcomes.

High Temperatures and Kidney Disease Morbidity: A Systematic Review and Meta-analysis

  • Lee, Woo-Seok;Kim, Woo-Sung;Lim, Youn-Hee;Hong, Yun-Chul
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.1
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    • pp.1-13
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    • 2019
  • Objectives: In recent years, serious concerns have been raised regarding the impacts of rising temperatures on health. The present study was conducted to investigate the relationship between elevated temperatures and kidney disease through a systematic review and meta-analysis. Methods: In October 2017, 2 researchers independently searched related studies in PubMed and Embase. A meta-analysis was conducted using a random-effects model, including only studies that presented odds ratios, relative risks, or percentage changes, along with 95% confidence intervals (CIs). The characteristics of each study were summarized, and the Egger test and funnel plots were used to evaluate publication bias. Results: Eleven studies that met the criteria were included in the final analysis. The pooled results suggest an increase of 30% (95% CI, 20 to 40) in kidney disease morbidity with high temperatures. In a disease-specific subgroup analysis, statistically significant results were observed for both renal colic or kidney stones and other renal diseases. In a study design-specific subgroup analysis, statistically significant results were observed in both time-series analyses and studies with other designs. In a temperature measure-specific subgroup analysis, significant results were likewise found for both studies using mean temperature measurements and studies measuring heat waves or heat stress. Conclusions: Our results indicate that morbidity due to kidney disease increases at high temperatures. We also found significant results in subgroup analyses. However, further time-series analyses are needed to obtain more generalizable evidence.

Serum vitamin D status and metabolic syndrome: a systematic review and dose-response meta-analysis

  • Lee, Kyueun;Kim, Jihye
    • Nutrition Research and Practice
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    • v.15 no.3
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    • pp.329-345
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    • 2021
  • BACKGROUD/OBJECTIVES: Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies. MATERIALS/METHODS: Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I2 statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis. RESULTS: The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76-0.84; I2 = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72-0.98; I2 = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS. CONCLUSIONS: Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

Is aromatherapy associated with patient's dental anxiety levels? A systematic review and meta-analysis

  • Purohit, Abhishek;Singh, Abhinav;Purohit, Bharathi;Shakti, Prateek;Shah, Nidhi
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.21 no.4
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    • pp.311-319
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    • 2021
  • The use of aromatherapy for the reduction of anxiety levels during dental treatment procedures has been well established in the literature; however, there is limited evidence regarding its efficacy. The present meta-analysis is an attempt to assess the association between the use of aromatherapy and anxiety levels among dental patients. A comprehensive search was conducted across Medline, Scopus, Web of Science, EBSCO host, Cochrane databases, and Google Scholar for studies evaluating aromatherapy and anxiety level among dental patients. PRISMA guidelines were followed for the meta-analysis. Randomized and cluster-randomized trials comparing aromatherapy with controls were included. The random-effects model was used to assess the mean differences in anxiety levels of patients visiting dental OPD. The significance value was set at P < 0.05. Six studies were identified that met the requirements for inclusion. Aromatherapy was significantly associated with reduction in patient anxiety levels during dental treatment (pooled mean difference: -3.36 [95% CI, -3.77 - -2.95, P = 0.00001). Low heterogeneity was noted between studies (I2 = 1%, P = 0.41) analyzed in the meta-analysis. High certainty of the evidence was obtained from the association between the use of aromatherapy and dental anxiety. This meta-analysis suggests that aromatherapy is effective in reducing dental anxiety. When used judiciously, the results of this work should encourage the use of aromatherapy to reduce patient anxiety levels during dental procedures

The Effect of Mind Awareness Records on Awareness of Imaginations, Decentering, Parenting stress and Subjective Well-bing: With a Focus on Parents of Adolescents (마음알아차리기 기록이 공상자각, 탈중심화, 양육스트레스 및 주관적 안녕감에 미치는 영향 : 청소년기 자녀를 둔 부모를 중심으로)

  • Jung, Hyun Gi;Sung, Seoung Yun
    • Journal of Family Relations
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    • v.20 no.4
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    • pp.73-103
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    • 2016
  • Objectives: The purpose of this study is to examine the effects of reading mind recording on awareness of imaginations, Method: Decentering, parenting stress and subjective well-being through comparing expressive writing. random assignment was performed on each 13 persons of a recording group (experimental group) and an expressive writing group (comparison group) for reading mind from 26 parents having adolescents. The experimental group conducted the reading of reading mind and the comparison group performed expressive writing twice a week for eight weeks, twenty minutes per time, and responded to four questions on thought arrangement after writing. The researcher participated in the groups once per week and an assignment was suggested once per week. Repeated Measurement Two-way Repeated Measures ANOVA was conducted to confirm the differences according to periods and groups for the data analysis method. In order to examine the changes according to periods, t-test was conducted on the pre- and post-test. Results: The findings are as follows: First, regarding awareness of imaginations and decentering, the reading mind recording group showed a significant result in repeated measurement. Second, the reading mind recording group showed a significant decrease in the pre- and post-t-test about parenting stress. Third, all the reading mind recording group and expressive writing group showed significant results about subjective well-being. Conclusions: This study is significant in that it verified the effectiveness of reading mind recording on awareness of imaginations, decentering and parenting stress, and proved the possibility as an oriental counseling model that considers the characteristics of our culture.

Vibration analysis of sandwich sector plate with porous core and functionally graded wavy carbon nanotube-reinforced layers

  • Feng, Hongwei;Shen, Daoming;Tahouneh, Vahid
    • Steel and Composite Structures
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    • v.37 no.6
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    • pp.711-731
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    • 2020
  • This paper deals with free vibration of FG sandwich annular sector plates on Pasternak elastic foundation with different boundary conditions, based on the three-dimensional theory of elasticity. The plates with simply supported radial edges and arbitrary boundary conditions on their circular edges are considered. The influence of carbon nanotubes (CNTs) waviness, aspect ratio, internal pores and graphene platelets (GPLs) on the vibrational behavior of functionally graded nanocomposite sandwich plates is investigated in this research work. The distributions of CNTs are considered functionally graded (FG) or uniform along the thickness of upper and bottom layers of the sandwich sectorial plates and their mechanical properties are estimated by an extended rule of mixture. In this study, the classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube random contact, which explicitly accounts for the progressive reduction of the tubes' effective aspect ratio as the filler content increases. The core of structure is porous and the internal pores and graphene platelets (GPLs) are distributed in the matrix of core either uniformly or non-uniformly according to three different patterns. The elastic properties of the nanocomposite are obtained by employing Halpin-Tsai micromechanics model. A semi-analytic approach composed of 2D-Generalized Differential Quadrature Method (2D-GDQM) and series solution is adopted to solve the equations of motion. The fast rate of convergence and accuracy of the method are investigated through the different solved examples. Some new results for the natural frequencies of the plate are prepared, which include the effects of elastic coefficients of foundation, boundary conditions, material and geometrical parameters. The new results can be used as benchmark solutions for future researches.

Prevalence and extension of the anterior loop of the mental nerve in different populations and CBCT imaging settings: A systematic review and meta-analysis

  • Hadilou, Mahdi;Gholami, Leila;Ghojazadeh, Morteza;Emadi, Naghmeh
    • Imaging Science in Dentistry
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    • v.52 no.2
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    • pp.141-153
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    • 2022
  • Purpose: This study aimed to identify the prevalence and extension of the anterior loop (AL) of the mental nerve in different populations and according to different cone-beam computed tomography (CBCT) imaging settings. Materials and Methods: Medline/PubMed, Embase, Scopus, Web of Science, and ProQuest were searched. The main inclusion criterion was ALs evaluated in CBCT images. The quality of studies was assessed with the Joanna Briggs Institute risk of bias checklist. Subgroup analyses were conducted for sex, side, continent, voxel size, field of view, and type of CBCT-reconstruction images with a random-effects model. Results: Sixty-three studies with 13,743 participants (27,075 hemimandibles) were included. An AL was found in 40.6% (95% CI: 32.8%-48.9%, P<0.05) of participants and 36.0% (95% CI: 27.5%-45.5%, P<0.05) of hemimandibles, in 34.9% (95% CI: 25.1%-46.2%, P<0.05) of males and 34.5% (95% CI: 23.5%-47.4%, P<0.05) of females. The average length of ALs was 2.39 mm (95% CI: 2.07-2.70 mm, P<0.05). Their extension was 2.13 mm (95% CI: 1.54-2.73 mm, P<0.05) in males and 1.85 mm (95% CI: 1.35-2.36 mm, P<0.05) in females. Significant differences were observed regarding the prevalence and length of ALs among continents and for its measured length on different CBCT-reconstruction images, but not between other subgroups. Conclusion: AL was a relatively common finding. The voxel size and fields of view of CBCT devices were adequate for assessing AL; however, a 2-mm safety margin from anatomical structures(such as the AL) could be recommended to be considered when using CBCT imaging.