• Steel and Composite Structures
• /
• v.17 no.5
• /
• pp.641-665
• /
• 2014

This paper presents the analytical solutions for the size-dependent static analysis of the functionally graded (FG) beams with various boundary conditions based on the nonlocal continuum model. The nonlocal behavior is described by the differential constitutive model of Eringen, which enables to this model to become effective in the analysis and design of nanostructures. The elastic modulus of beam is assumed to vary through the thickness or longitudinal directions according to the power law. The governing equations are derived by using the nonlocal continuum theory incorporated with Euler-Bernoulli beam theory. The explicit solutions are derived for the static behavior of the transversely or axially FG beams with various boundary conditions. The verification of the model is obtained by comparing the current results with previously published works and a good agreement is observed. Numerical results are presented to show the significance of the nonlocal effect, the material distribution profile, the boundary conditions, and the length of beams on the bending behavior of nonlocal FG beams.

• Structural Engineering and Mechanics
• /
• v.78 no.2
• /
• pp.199-207
• /
• 2021

In the present paper, an analytical model is proposed to determine the flexural and shear strength of normal and high-strength reinforced concrete beams with longitudinal bars, in the presence of transverse stirrups. The model is based on evaluation of the resistance contribution due to beam and arch actions including interaction with stirrups. For the resistance contribution of the main bars in tension the residual bond adherence of steel bars, including the effect of stirrups and the crack spacing of R.C. beams, is considered. The compressive strength of the compressed arch is also verified by taking into account the biaxial state of stresses. The model was verified on the basis of experimental data available in the literature and it is able to include the following variables in the resistance provision: - geometrical percentage of steel bars; - depth-to-shear span ratio; - resistance of materials; - crack spacing; - tensile stress in main bars; - residual bond resistance including the presence of stirrups;- size effects. Finally, some of the more recent analytical expressions able to predict shear and flexural resistance of concrete beams are mentioned and a comparison is made with experimental data.

• Asian-Australasian Journal of Animal Sciences
• /
• v.27 no.5
• /
• pp.628-634
• /
• 2014

Data on age and body weight at breeding, parity, previous litter size, days open and some descriptive body linear traits from 389 meat-type, prolific Black Bengal goats in Tripura State of India, were collected for 3 and 1/2 years (2007 to 2010) and analyzed using logistic regression model. The objectives of the study were i) to evaluate the effect of age and body weight at breeding, parity, previous litter size and days open on litter size of does; and ii) to investigate if body linear type traits influenced litter size in meat-type, prolific goats. The incidence of 68.39% multiple births with a prolificacy rate of 175.07% was recorded. Higher age (>2.69 year), higher parity order (>2.31), more body weight at breeding (>20.5 kg) and larger previous litter size (>1.65) showed an increase likelihood of multiple litter size when compared to single litter size. There was a strong, positive relationship between litter size and various body linear type traits like neck length (>22.78 cm), body length (>54.86 cm), withers height (>48.85 cm), croup height (>50.67 cm), distance between tuber coxae bones (>11.38 cm) and distance between tuber ischii bones (>4.56 cm) for discriminating the goats bearing multiple fetuses from those bearing a single fetus.

• Genomics & Informatics
• /
• v.10 no.2
• /
• pp.117-122
• /
• 2012

A sample size with sufficient statistical power is critical to the success of genetic association studies to detect causal genes of human complex diseases. Genome-wide association studies require much larger sample sizes to achieve an adequate statistical power. We estimated the statistical power with increasing numbers of markers analyzed and compared the sample sizes that were required in case-control studies and case-parent studies. We computed the effective sample size and statistical power using Genetic Power Calculator. An analysis using a larger number of markers requires a larger sample size. Testing a single-nucleotide polymorphism (SNP) marker requires 248 cases, while testing 500,000 SNPs and 1 million markers requires 1,206 cases and 1,255 cases, respectively, under the assumption of an odds ratio of 2, 5% disease prevalence, 5% minor allele frequency, complete linkage disequilibrium (LD), 1:1 case/control ratio, and a 5% error rate in an allelic test. Under a dominant model, a smaller sample size is required to achieve 80% power than other genetic models. We found that a much lower sample size was required with a strong effect size, common SNP, and increased LD. In addition, studying a common disease in a case-control study of a 1:4 case-control ratio is one way to achieve higher statistical power. We also found that case-parent studies require more samples than case-control studies. Although we have not covered all plausible cases in study design, the estimates of sample size and statistical power computed under various assumptions in this study may be useful to determine the sample size in designing a population-based genetic association study.

• Journal of Industrial Technology
• /
• v.22 no.A
• /
• pp.229-240
• /
• 2002

This paper is an experimental and numerical work of Investigating the bearing capacity of shallow foundation of rubble mound under eccentric loads. Parametric centrifuge model tests at the 50g level environments with the model footings in the form of strip footing were performed by changing the loading location of model footing, relative density and materials for ground foundation. For the model ground, crushed rock sampled from a rocky mountain was prepared with a grain size distribution of having an identical coefficient of uniformity to the field condition. Model ground was also prepared with relative densities of 50 % and 80 %. For loading condition, model tests with and without eccentric load were carned out to investigate the effect of eccentric loads and a numerical analysis with the commertially available software of FLAC was performed. For numerical estimation with FLAC, the hyperbolic model of a nonlinear elastic constitutive relationship was used to simulate the stress-stram constitutive relationship of model ground and a series of triaxial compression test were carried out to find the parameters for this model Test results were analyzed and compared with Meyerhof method (1963), effective area method based on the limit equilibrium method, and a numerical analysis with FLAC.

• IE interfaces
• /
• v.16 no.3
• /
• pp.362-374
• /
• 2003

The major objective of this paper is to empirically examine the effect of process maturity on the performance of industrial R&D projects. Process maturity, a fundamental concept of the Capability Maturity Model developed by Software Engineering Institute, represents the essential of Total Quality Management (TQM). Based on literature, our research model constructs process maturity in terms of structured process, goal setting and controlling, metrics, and process learning; and links it to the R&D performance that consists of technical, commercial and managerial successes. The model also includes firm size as a moderator of different effects that process maturity may have across firms. Measures for process maturity are based on the best practices identified in literature. Data are obtained from 77 successful R&D projects carried out by Korean manufacturing firms. Multiple regression and t-test are used to test proposed hypotheses. Findings are as follows. (1) In the R&D process, process maturity partially contributes to the performance of R&D projects. More specifically, goal setting and controlling-related practices drive both technical and commercial successes, while process learning-related practices drive commercial success. In contrast, traditionally emphasized elements such as structured process or metrics are found not to be significant. (2) The degree of process maturity is significantly higher in large firms. (3) Process maturity impacts on commercial success in the case of large firms, whereas it does on technical success in the case of small firms. The results imply that the TQM principles are partially associated with R&D performance, and the nature of benefit from high maturity could vary according to firm size.

• Journal of Preventive Medicine and Public Health
• /
• v.57 no.5
• /
• pp.435-442
• /
• 2024

Objectives: The aim of this study was to investigate the significance of associations between knowledge, professional ethics, institutional support, perceptions regarding HIV/AIDS, and HIV/AIDS-related stigma among health workers in West Sumatra, Indonesia. Methods: We conducted a cross-sectional study involving health workers at public hospitals and health centers in West Sumatra in June 2022. The Health Care Provider HIV/AIDS Stigma Scale was employed to assess the stigma associated with HIV/AIDS. To estimate and evaluate the model's ability to explain the proposed constructs, we utilized the standardized partial least squares structural equation model (PLS-SEM). Results: In total, 283 individuals participated in this study (average age, 39 years). The majority were female (91.2%), nearly half were nurses (49.5%), and 59.4% had been working for more than 10 years. The study revealed that HIV/AIDS-related stigma persisted among health workers. The PLS-SEM results indicated that all latent variables had variance inflation factors below 5, confirming that they could be retained in the model. Knowledge and professional ethics significantly contributed to human immunodeficiency virus (HIV)-related stigma, with an effect size (f²) of 0.15 or greater. In contrast, perceived and institutional support had a smaller impact on HIV-related stigma, with an effect size (f²) of at least 0.02. The R² value for health worker stigma was 0.408, suggesting that knowledge, professional ethics, institutional support, and perceived support collectively explain 40.8% of the variance in stigma. Conclusions: Improving health workers' understanding of HIV, fostering professional ethics, and strengthening institutional support are essential for reducing HIV-related stigma in this population.

• The Korean Journal of Applied Statistics
• /
• v.28 no.5
• /
• pp.1035-1046
• /
• 2015

Variance components models incorporate various random factors in the form of linear models. There are two experimental Layouts for the classification of factors under variance components models: nested classification and crossed classification. We consider two-way variance components models and investigate the effect of experimental Layout on the performance of model selection criteria AIC and BIC. The effect of experimental Layout is studied through a simulation study with various combinations of parameters in a systematic fashion. The simulation study shows differences in performance of model selection methods between the two classification. There is a particular tendency to prefer the smaller model than the true model when the variance component of a nested factor becomes relatively larger than a nesting factor that is persistent even when the sample size is not small.

• Tribology and Lubricants
• /
• v.1 no.1
• /
• pp.38-45
• /
• 1985

Ferrograms prepared from off samples collected during testing in the transition region were originally diluted at 20:1. To obtain some information about the effect of dilution on the analysis procedures, a series of measurements were made on ferrograms prepared to different dilutions in the range 6 to 30:1 from oil samples collected after testing in the four ball machine at the 51 kg and 55 kg load, respectively, Fig. 1. The variations in area covered, perimeter, intercept and particle count were then plotted as a function of dilution level and appropriate mathematical expressions established such that the results obtained at any dilution level specified within the range can then be corrected back to an equivalent undiluted value. The effect of dilution on the variance of the particle size distribution was also investigated. The main results are tabulated, Tables 1-5 and also plotted as a function of dilution, level Figs. 2-9.

• Journal of Korean Academy of Nursing
• /
• v.41 no.5
• /
• pp.704-714
• /
• 2011

Purpose: The purpose of this study was to determine whether psychological distress is an independent risk factor for recurrent cardiac events in patients with coronary artery disease (CAD). Methods: A prospective cohort of studies that measured psychological distress and the incidence of recurrent cardiac events in the adult population were included. Three computerized databases were assessed (PubMed, CINAHL, and PSYCINFO). Meta-analysis was conducted using a random-effects model to determine summary estimates of risks of major recurrent cardiac events associated with each psychological distress. Of 506 publications identified, 33 met inclusion criteria, and 24 studies were used to estimate effect size of psychological distress on recurrent cardiac events. Results: Mean number in the research sample was 736 and mean time of follow-up was 4.0 years. Depression, anxiety, anger, and hostility as psychological factors were studied. According to estimation of effect size using random model effect, depression (OR=1.39, 95% CI: 1.22-1.57), anxiety (OR=1.22, 95% CI: 0.96-1.56), and anger/hostility (OR=1.29, 95% CI: 1.07-1.57) CAD patients in significantly increased risk for recurrent cardiac events. Conclusion: Finding suggests that psychological distress in forms of depression, anxiety, anger, and hostility impact unfavorably on recurrent cardiac events in CAD patients.