• Title/Summary/Keyword: size effect model

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The Analysis of Terrain Height Variance Spectra over the Korean Mountain Region and Its Impact on Mesoscale Model Simulation (한반도 산악 지역의 지형분산 스펙트럼과 중규모 수치모의에서의 효과 분석)

  • An, Gwang-Deuk;Lee, Yong-Hui;Jang, Dong-Eon;Jo, Cheon-Ho
    • Atmosphere
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    • v.16 no.4
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    • pp.359-370
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    • 2006
  • Terrain height variance spectra for the Korean mountain region are calculated in order to determine an adequate grid size required to resolve terrain forcing on mesoscale model simulation. One-dimensional spectral analysis is applied to specifically the central-eastern part of the Korean mountain region, where topographical-scale forcing has an important effect on mesoscale atmospheric flow. It is found that the terrain height variance spectra in this mountain region has a wavelength dependence with the power law exponents of 1.5 at the wavelength near 30 km, but this dependence is steeply changed to 2.5 at the wavelength less than 30 km. For the adequate horizontal grid size selection on mesoscale simulation two-dimensional terrain height spectral analysis is also performed. There is no directionality within 50% of spectral energy region, so one-dimensional spectral analysis can be reasonably applied to the Korea Peninsula. According to the spectral analysis of terrain height variance, the finer grid size which is higher than 6 km is required to resolve a 90% of terrain variance in this region. Numerical simulation using WRF (Weather Research and Forecasting Model) was performed to evaluate the effect of different terrain resolution in accordance with the result of spectral analysis. The simulated results were quantitatively compared to observations and there was a significant improvement in the wind prediction across the mountain region as the grid space decreased from 18 km to 2 km. The results will provide useful guidance of grid size selection on mesoscale topographical simulation over the Korean mountain region.

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.

A Meta-Analysis of Librarians' Job Satisfaction Studies (사서의 직무만족도에 관한 메타분석 연구)

  • Ro, Jung-Soon
    • Journal of the Korean Society for information Management
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    • v.25 no.3
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    • pp.273-296
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    • 2008
  • This study conducted meta-analysis of librarians' job satisfaction using the Hedges & Olkin's Effect Size Model. Sex and Marrage as group variables, and Total Satisfaction and 7 sub-variables(Work Itself, Salary, Promotion, Supervision, Working Conditions, Social Recognition, Self-actualization) as dependent variables were selected from 27 studies. The effect sizes between men and women were significantly different on Supervision, Working conditions, Promotion, and Social Recognition, of which first two were homogeneous. But the difference of Social Recognition was not significant in Random Effect Model. The effect sizes difference between married and unmarried were significant on Self Recognition, Salary, and Work Itself. However the difference of Work Itself was not significant in Random Effect Model. Study Year could not be a moderator.

The Effect of Hospital Web Service Quality on Initial Trust and Off-line Visit Intention: Focusing on Medium and Small Size Hospital (웹서비스품질이 초기신뢰와 오프라인 방문의도에 미치는 영향: 중소병원을 중심으로)

  • Kim, Sang-Han;Cho, Chul-Ho
    • Journal of Korean Society for Quality Management
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    • v.42 no.3
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    • pp.445-458
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    • 2014
  • Purpose: Present study was designed to examine the casual relationships among web service quality, customer satisfaction, initial trust and off-line visit intention in hospital website. Research object was limited to web service quality of general hospital. We applied path analysis model in order to test the hypotheses and research model. Methods: Survey tool, that is, Questionnaire had obtained validity through literature survey, exploratory survey and pretest and sample 320 was selected. For statistical treatment of pretest and main analysis, SPSS18.0 and AMOS18.0 were employed and Structural equation model was employed as analysis method. Results: Result of this study shows as follows. Factors of web service quality have an effect on customer satisfaction and initial trust, both of customer satisfaction and initial trust have an effect on off-line visit intention. Also customer satisfaction affects initial trust. Especially, customer satisfaction and initial trust were empirically confirmed as the important factors preceding off-line vis it intention. Conclusion: Therefore, present study shows that customer satisfaction and initial trust are important factors that medium and small size hospitals have to emphasize to raise performance. However, present study has some limitations to additionally research in the future.

Development of Laminar Box Manufacturing Technique for Earthquake Engineering (내진 연구를 위한 전단상자 제작기술 개발)

  • 이용재
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.04a
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    • pp.100-107
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    • 2001
  • One major problem in the model testing is the boundary effect and size effect caused by the limit in the size of the container. To overcome this problem, various types of laminar boxes are gradually manufactured and used in the shaking table test, which ideally has zero stiffness to horizontal shear. In this study, a small-scale laminar box is manufactured, which is composed of 6 thin aluminum rectangular hollow plates, and its inside dimensions are 300 mm length by 200 mm width by 350 mm depth. Shaking table tests are performed both with the laminar box and the rigid box under the same conditions, where displacements and accelerations are measured at various points of the box and model ground. As result of analyzing the measured data, during the propagation of input seismic motion from the bottom to the ground surface, the relative displacement of the model ground and the amplification of acceleration is hardly amplified in the rigid box. Because of the effect of stress waves reflecting from the rigid wall, the acceleration is slightly decreased at the edge in the rigid box. The laminar box, manufactured in this study, has a problem in that the soil behavior at the edge of ground surface is affected by the inertia force of the top layer due to its excessive self-weight.

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Effect of the Shape of Absorbing Revetment on Wave Overtopping Rate (소파호안의 형상이 월파량에 미치는 영향)

  • Hur, Dong-Soo;Choi, Dong-Seok;Choi, Sun-Ho
    • Journal of Ocean Engineering and Technology
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    • v.22 no.6
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    • pp.7-12
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    • 2008
  • The present study numerically investigates the effect of the shape of absorbing revetment on wave overtopping rate under regular and irregular incident waves. At first, the numerical model developed by Hur and Choi(2008), which considers the flow through a porous medium with inertial, laminar and turbulent resistance terms, directly simulates Wave-Structure-Sandy seabed interaction and can determine the eddy viscosity with LES turbulent model in 2-Dimensional wave field (LES-WASS-2D), is validated when compared to experimental data. Numerical simulations are then performed to examine the effect of the shape of absorbing revetment and incident wave conditions on wave overtopping rate. The numerical result shows that the wave overtopping rate decreases with the slope gradient of absorbing revetment under both regular and irregular waves. In addition, the effects of mean grain size and porosity of absorbing revetment, incident wave period and crest height on wave overtopping rate are discussed.

Effect of Dietary Soybean Protein on Cerebral Infarction Size and Antioxidant Enzyme Activities in Rat Focal Brain Ischemia Model (쥐의 대두 단백질 섭취가 국소 뇌허혈/재관류 후 뇌경색 크기와 항산화효소 활성도에 미치는 영향)

  • Lee, Hee-Joo
    • Journal of Korean Biological Nursing Science
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    • v.10 no.1
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    • pp.1-10
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    • 2008
  • Purpose: The purpose of this study was to investigate the cerebral infarction size, antioxidant enzyme activities and lipid peroxidation changes after 6 weeks of dietary soybean protein intake in a rat focal brain ischemia model. Method: Weaning Sprague-Dawley rats were fed with either modified AIN-93G diet containing casein 20% (control), 20% soybean protein isolate-based diet (S20), or 40% of soybean protein isolate-based diet (S40) for 6 weeks. The animals were subject to right middle cerebral artery occlusion for 2 hr. After 24 hr of recirculation, the rats were sacrificed. Antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and thiobarbituric acid reactive substance (TBARS) level in the right brain were also measured. Result: There were no significant differences in the right cortical infarction volume, TBARS level, SOD and CAT activities among the three groups whereas the GPx activities of the S20 group were significantly higher than those of the control group (p=.02). Conclusion: Our results suggest that 20% of soybean protein may have a modulating effect on GPx and possibly have some protective effect against oxidative stress although it may enough to decrease cerebral infarction volume in rat focal brain ischemia model.

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Effect of pore size and porosity on electrical breakdown behaviors of $BaTiO_3$ ceramics ($BaTiO_3$ 세라믹의 절연파괴거동에 미치는 기공의 크기와 기공율의 영향)

  • 조경호;우동찬;남효덕;이희영
    • Electrical & Electronic Materials
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    • v.10 no.3
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    • pp.255-261
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    • 1997
  • In this study, pore-containing barium titanate ceramics were prepared with different porosities and pore sizes, in order to better understand how porosity and pore size affect electrical breakdown of barium titanate ceramics. A granulated barium titanate powder was mixed with three grades of commercial polymer microspheres up to 11wt%. The electrical breakdown test was performed at two different temperatures of 30.deg. C(below Tc) and 150.deg. C(above Tc) for samples immersed in a silicon oil bath using a 60kV de power supply. Electrical breakdown strength of pore containing barium titanate ceramics with porosity lower than 10% decreased as pore size and porosity increased. However, above the 10% porosity region, electrical breakdown strength decreased as the pore connectivity increased. From the experimental results, an optimum electrical breakdown model is proposed in an attempt to explain the effect of pores.

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Effect of Community-based Rehabilitation on Patients with Brain Injury: Meta-analysis Based on the ICF Model (뇌손상 환자의 지역사회재활(CBR) 프로그램의 효과: ICF 모델에 근거한 메타분석)

  • Cha, Yu-Jin;Kim, Se-Yun
    • The Journal of the Korea Contents Association
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    • v.14 no.3
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    • pp.203-214
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    • 2014
  • In this study, a meta-analysis was conducted to investigate the effect of community-based rehabilitation on patients with brain injury by ICF factor in previous studies and examine the application of recent community-based rehabilitation program. Total 15 articles that satisfied the selection criteria were divided by ICF factors to obtain the effect size. Homogeneity and publication bias were tested for those selected papers. As a result, the overall effect size of community-based rehabilitation was 0.22; the effect size by physical function and structure among the ICF factors came to be 0.21; and the effect size of activity and participation was 0.20, indicating a small effect size. The studies involved in a meta-analysis were considered as the absence of heterogeneity and publication bias, which indicates that the results of this study are subjectively reliable. These results well explained the level of change on ICF factors, especially physical function and structure, activity and participation, in other words, the intervention effect of community-based rehabilitation on patients with brain injury.

A Meta-Analysis on the Effect of Music Intervention on the Anxiety of Children and Adolescents (음악중재가 아동 및 청소년의 불안에 미치는 효과에 대한 메타분석)

  • Bae, Ik-lyul;Kim, Min-woong
    • Stress
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    • v.25 no.2
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    • pp.86-92
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    • 2017
  • The present study investigated the effect of music intervention on the anxiety of children and adolescents using meta-analysis, and the specific research purposes were as follows. The targets of the present study were previous studies analyzed the effect of music intervention on anxiety collected the final 28 theses for academic degrees and five scholarly journal articles were used in the analysis. To examine the publication bias of the studies used in the analysis, funnel plot and fail-safe N were verified, and found the publication bias was not significant enough to influence the present study. The homogeneity test showed that the effect size was heterogeneous, and accordingly, a random effect model analysis was carried out and the overall effect size was found to be -1.034. The analysis on the difference in the effect showed that the effect size varied according to subject classification and intervention location for categorical variables and size for continuous variables.