• Title/Summary/Keyword: size effect model

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A Study on Numerical Analysis for 2 Dimensional Circulation Model with Effect of Nonlinear Term (비선형항의 효과를 고려한 2차원 유동모형에 대한 수치해석연구)

  • 김희종;김진후;이상화
    • Journal of Ocean Engineering and Technology
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    • v.4 no.1
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    • pp.49-54
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    • 1990
  • This study describes the application of a two dimensional depth integrated numerical model. The explict scheme of finite difference method had been applied to the model of circulation. The nonlinear terms showed a slight difference for the variations of water elevation when calculated grid was small. They were also found to be minor when calculated grid size was increased. For verification of the numerical model, numerical results were compared with predicted values and field data. In the model, the effect of nonlinear advective terms proved not to be significant.

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The effect of particle size on the determinability of maize composition in reflection mode.

  • MVaradi, Maria;Turza, Sandor
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1129-1129
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    • 2001
  • Maize, in Hungary, is the fodder-plant grown in the biggest quantity. It is not only used as a fodder but other products such as iso-sugar are made from it, too. The quality of the fodder and the produce is largely dependent on the composition of the supplied maize to the processing site. The examination of quality parameters besides conventional methods are investigated and measured by NIR spectroscopy on a routine basis. The investigated parameters are the following: water, total protein, starch and oil content. The accuracy and precision of determining these parameters we, apart from the wet chemical methods, influenced by sample preparation to a great extent. One of the main features of this is the sample particle size and its distribution across the sample. The uneven distribution of particle size negatively influences the measurement accuracy, decreases model robustness and prediction ability. With these in mind the aim of our experiment was to investigate the effect of particle size on the accuracy of maize composition determination using reflection measurement setup. In addition, we tested different spectrum transformations, which are suitable for canceling this effect. In our experiment 47 samples were analyzed with three different mesh sizes (1.5mm, 1.8mm and 2mm). The results of our findings are presented here.

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The effects of coordinative locomotor training on balance in patients with chronic stroke: meta-analysis of studies in Korea (협응이동훈련이 만성 뇌졸중 환자의 균형에 미치는 효과: 국내연구의 메타분석)

  • Lim, Jae Heon;Park, Se Ju
    • Journal of Korean Physical Therapy Science
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    • v.27 no.2
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    • pp.36-47
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    • 2020
  • Background: This study purposed to provide meaningful information for the accumulation of knowledge on coordinative locomotor training in patients with stroke. Design: Meta-analysis. Methods: This study collected articles which the coordinative locomotor training in patients with stroke. For systematic meta-analysis, 6 articles were finally selected after searching based on the PICOSD criteria. This meta-analysis was conducted according to PRISMA guidelines. Randomized controlled trials were included and the risk of bias was evaluated for each study. Pooled standardized mean differences were calculated using a random effects model. To extract the effect size of each study, the R 3.5.3 software was used. Results: The meta-analysis showed that a total effects size was 1.23 indicating that coordinative locomotor training for patients with stroke had a maximum effect size. Conclusion: A meta-analysis is warranted for further research to determine the effects of coordinative locomotor training in patients with stroke on muscle strength, walking and range of motion.

The External Knowledge Utilization and Radical Innovation in Korea Electronic Industry

  • Lee, Youngwoo;Kim, Jae-Jin;Chang, Sul-Ki
    • East Asian Journal of Business Economics (EAJBE)
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    • v.6 no.4
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    • pp.13-24
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    • 2018
  • Purpose - This study investigates the moderation effect of internal factor, a firms size, on the external knowledge sourcing strategy and its effectiveness in generating radical innovation. We incorporate concepts of breadth and depth as two measures to gauge the degree of openness in firms external search Research design and methodology - The dependent variable in the regression model is the percentage of innovative sales and therefore, Tobit regression is employed for estimating significant factors affecting on the ratio of first-to-market by breadth and depth in external knowledge, internationalization, and size. Results - The results show that the external knowledge, in terms of both breadth and depth, has a positive relationship with radical innovation. However internationalization as external knowledge resources is not statistically accepted. Firm size has moderating effect on innovation negatively only in case of using external knowledge resources to a high degree. Conclusions - Firms obtain external information mostly from customers, competitors, and suppliers etc. empirical knowledge in terms of scope and intensity is an important contributor to innovation. And intensity use of external knowledge and information resources can work in favor of smaller firms rather than larger ones. Internationalization seems to have little effect on innovation but it requires further researches with clear criteria and more data.

A combined stochastic diffusion and mean-field model for grain growth

  • Zheng, Y.G.;Zhang, H.W.;Chen, Z.
    • Interaction and multiscale mechanics
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    • v.1 no.3
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    • pp.369-379
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    • 2008
  • A combined stochastic diffusion and mean-field model is developed for a systematic study of the grain growth in a pure single-phase polycrystalline material. A corresponding Fokker-Planck continuity equation is formulated, and the interplay/competition of stochastic and curvature-driven mechanisms is investigated. Finite difference results show that the stochastic diffusion coefficient has a strong effect on the growth of small grains in the early stage in both two-dimensional columnar and three-dimensional grain systems, and the corresponding growth exponents are ~0.33 and ~0.25, respectively. With the increase in grain size, the deterministic curvature-driven mechanism becomes dominant and the growth exponent is close to 0.5. The transition ranges between these two mechanisms are about 2-26 and 2-15 nm with boundary energy of 0.01-1 J $m^{-2}$ in two- and three-dimensional systems, respectively. The grain size distribution of a three-dimensional system changes dramatically with increasing time, while it changes a little in a two-dimensional system. The grain size distribution from the combined model is consistent with experimental data available.

Modeling the size effect on vibration characteristics of functionally graded piezoelectric nanobeams based on Reddy's shear deformation beam theory

  • Ebrahimi, Farzad;Fardshad, Ramin Ebrahimi
    • Advances in nano research
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    • v.6 no.2
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    • pp.113-133
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    • 2018
  • In this work, free vibration characteristics of functionally graded piezoelectric (FGP) nanobeams based on third order parabolic shear deformation beam theory are studied by presenting a Navier type solution as the first attempt. Electro-mechanical properties of FGP nanobeam are supposed to change continuously throughout the thickness based on power-law model. To capture the small size effects, Eringen's nonlocal elasticity theory is adopted. Using Hamilton's principle, the nonlocal governing equations for third order shear deformable piezoelectric FG nanobeams are obtained and they are solved applying analytical solution. By presenting some numerical results, it is demonstrated that the suggested model presents accurate frequency results of the FGP nanobeams. The influences of several parameters including, external electric voltage, power-law exponent, nonlocal parameter and mode number on the natural frequencies of the size-dependent FGP nanobeams is discussed in detail.

A Meta-analysis of Relationship between Constructs of the Technology Acceptance Model: Focusing on the Research Papers Published for Smartphone in Korea Journals (기술수용모델 개념 간의 관계에 대한 메타분석: 우리나라 학회지에 게재된 스마트폰 연구 중심으로)

  • Nam, Soo Tai;Jin, Chan Yong
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.8 no.4
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    • pp.67-79
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    • 2013
  • A meta-analysis is a statistical literature synthesis method that provides the opportunity to view the research context by combining and analyzing the quantitative results of many empirical studies. The technology acceptance model (TAM) has been the subjects of a great deal of MIS research in the last two decades and now also has been continuously studied. Recently, the convergence of knowledge information society and information telecommunication technologies has a rapid impact on politics, economics and various fields. The biggest issue in the information communication and information systems fields is smart. Therefore, we conducted a meta-analysis research on the behavioral intention of smart phone users based on technology acceptance model. Also, this study was targeted a total of 50 research papers that are setting up the causal relationship in TAM among the research papers published in domestic academic journals since 2005. The result of the meta analysis, showed that the effect size was 0.48 in the path from perceived usefulness to behavioral intention, it showed that the effect size was 0.46 in the path from perceived ease of use to behavioral intention. And, it showed that the effect size was 0.46 in the path from perceived ease of use to perceived usefulness. Also, it showed that the effect size was 0.61 in the path from attitude to behavioral intention. Based on the results, it was discussed the difference through comparative analysis with previous research.

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A Meta Analysis and Review of External Constructs Based on the Technology Acceptance Model: Focusing on the Research Related of Smartphone in Korea (기술수용모델 관련 외부요인에 관한 문헌적 고찰 및 메타분석: 우리나라 학회지에 게재된 스마트폰 관련연구 중심으로)

  • Nam, Soo-tai;Kim, Do-goan;Jin, Chan-yong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.254-257
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    • 2013
  • A Meta-analysis is a statistical literature synthesis method that provides the opportunity to view the research context by combining and analyzing the quantitative results of many empirical studies. The Technology Acceptance Model (TAM) has been the subjects of a great deal fields and now also has been continuously studied. Recently, the issue of the biggest the information communication and information systems fields is smart. At this point, we conducted a Meta-analysis and review of external constructs based on the technology acceptance model. This study was targeted a total of 106 research papers that are setting up the causal relationship in the technology acceptance model among the research papers published in domestic academic journals before 2013. The result of the Meta-analysis, the biggest effect size the path from external Variables to perceived usefulness was showed playfulness. The effect size was 0.536 in the path from perceived usefulness to playfulness. And, the biggest effect size the path from external Variables to perceived ease of use was showed self efficacy. The effect size was 0.536 in the path from perceived ease of use to self efficacy. Based on the results, it was discussed the difference through comparative analysis with previous research.

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Deformation Analysis of Micro-Sized Material Using Strain Gradient Plasticity

  • Byon S.M.;Lee Young-Seog
    • Journal of Mechanical Science and Technology
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    • v.20 no.5
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    • pp.621-633
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    • 2006
  • To reflect the size effect of material $(1\sim15{\mu}m)$ during plastic deformation of polycrystalline copper, a constitutive equation which includes the strain gradient plasticity theory and intrinsic material length model is coupled with the finite element analysis and applied to plane strain deformation problem. The method of least square has been used to calculate the strain gradient at each element during deformation and the effect of distributed force on the strain gradient is investigated as well. It shows when material size is less than the intrinsic material length $(1.54{\mu}m)$, its deformation behavior is quite different compared with that computed from the conventional plasticity. The generation of strain gradient is greatly suppressed, but it appears again as the material size increases. Results also reveal that the strain gradient leads to deformation hardening. The distributed force plays a role to amplify the strain gradient distribution.

Wage Differentials between Standard and Non-standard Workers: Assessing the Effects of Labor Unions and Firm Size (정규직과 비정규직의 임금격차 : 노동조합과 기업규모의 영향을 중심으로)

  • Lee, Injae;Kim, Tai Gi
    • Journal of Labour Economics
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    • v.32 no.3
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    • pp.1-26
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    • 2009
  • Using panel data from the Korean Labor and Income Panel Study(KLlPS), we examine the wage differentials between standard and Don-standard workers. To control for unobserved individual heterogeneities, we estimate the fixed effect models. Our results show that the OLS estimates are upwardly biased. We also find that labor unions and firm size are important determinants of the wage differentials.

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