• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.820-828
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• 2003

Recent research has indicated that the current ACI shear provision provides unconservative predictions for large slender beams and beams with low level of longitudinal reinforcement, and conservative results for deep beams. To modify some problems of ACI shear provision, ultimate shear strength equation considering size effect and arch action to compute shear strength in high-strength concrete beams without stirrups is presented in this research. Three basic equations, namely size reduction factor, rho factor, and arch action factor, are derived from crack band model of fracture mechanics, analysis of previous some shear equations for longitudinal reinforcement ratio, and concrete strut described as linear prism in strut-tie model deep beams. Constants of basic equations are determined using statistical analysis of previous shear testing data. To verify proposed shear equation for each variable, effective depth, longitudinal reinforcement ratio, concrete compressive strength and shear span-to-depth ratio, about 300 experimental data are used and proposed shear equation is compared with ACI 318-99 code, CEB-FIP Model code, Kim &Park's equation and Zsutty's equation. The proposed shear equation is not only simpler than other shear equations, it is but also shown to be economical predictions and reasonable safety margin. Hence proposed shear strength equation is expected to be applied to practical shear design.

• International Commerce and Information Review
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• v.11 no.1
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• pp.485-515
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• 2009

In this study aims to research and analyze what are decision factors between a wholly-owned subsidiary and a international company cooperation in the internationalization process. From 57 primary studies found 26 observed variables for aggregation of effect size in the using "Fixed Effect Model" on this mata-analysis. The article also links the theories that are used in the literature, not considered in the most of primary studies, to the empirical results and recommends global management strategy which is needed for business practical affairs. According to the result, the meta-analysis suggests that the number of employees of a MNC, the geological and cultural differneces between the host country and home country, the country-specific international experience of the MNC and export intensity, the international product diversification, the market growth and the market size of the foreign operations, and resource intensity of the foreign operations, the legal restrictions in the host country and the country risk of the home country do exert a significant effect on the decision between cooperative arrangement and a wholly-owned subsidiary. Conversely, for a large number of variables, no significant relationship seems to exist based on the combined results. This is the case, for example, for factor specificity, the r&d-intensity, the subsidiary size, the assets of the MNC and the sales volume of the MNC.

• The Journal of Industrial Distribution & Business
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• v.6 no.2
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• pp.5-11
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• 2015

Purpose - This research investigates the effect of disclosure quality with two main components, reliability and timeliness, on economic value added in Iran. Research design, data, and methodology - The sampling includes 170 Tehran Stock Exchange listed companies from 2008-12. Multiple regression analysis was applied to test the hypotheses and estimates of the coefficients. Firm size and return on assets were the control variables. Results - The results show that timeliness of information has a positive impact on economic value added. We did not find any significant relationship between disclosure quality and reliability of information and economic value added. The regressed model shows that there is no significant association between firm size and economic value added. The results also show that there is a positive association between return on assets and economic value added. Conclusions - Theoretically, timely information is effective in decision-making. This study shows that timeliness of information has positive effect on the creation of economic value added. However, disclosure quality, reliability, and firm size do not effect on economic value added. Companies with greater return on assets produce greater economic value added.

• Journal of Korean Public Health Nursing
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• v.33 no.3
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• pp.409-419
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• 2019

Purpose: Factors related to the major satisfaction of nursing students were systematically searched and quantitatively synthesized. Methods: Meta-analysis was conducted upon 47 articles in Korean master and doctorate degree dissertations and academic journals. Meta-analysis of major satisfaction-related variables was conducted using Comprehensive Meta-Analysis (CMA) 2.0 program. The effect size of the related variables was analyzed by converting the statistic r value to Fisher's Z. Results: The overall average effect size of major satisfaction was the largest effect size (ES=.49), followed by cognitive factors (ES=.58), affective factors (ES=.45), and psychomotor factors (ES=.31). The cognitive factors were in the order nursing professionalism(ES=.70), nurse's image (ES=.65), and critical thinking disposition (ES=.36). The affective factors were self-esteem (ES=.59), emotional intelligence (ES=.55), career identity (ES=.49), self-efficacy (ES=.48), college adjustment (ES=.45), practice satisfaction (ES=.45), resilience (ES=.42), (ES=.40), grit (ES=.34), and stress (ES=.26). The psychomotor factors were clinical performance ability (ES=.38) and career search behavior (ES=.31). Conclusion: The results of this study are valuable when giving consideration to the variables related to nursing students' major satisfaction, for developing a strategic model to enhance the satisfaction of nursing students.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.413-419
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• 2011

The nano-size hoenycomb structures have the higher ratio of the surface to the volume than macro-size honeycomb structures, and they can maximize the functionality of the electrical and chemical catalyst. The mechanical behaviors of the nano-sized structures are different from ones of the macro-size structure, and it is caused by the surface effect. This surface effect can be investigated by the atomistic simulation; however, the prediction of mechanical behaviors of the nano-sized honeycombs are practically impossible due to excessive computational resources and computation time. In this paper, by combining the bridging method considering the surface stress elasticity model with homogenization method, the mechanical behaviors of the nano-sized honeycombs are predicted efficiently.

• Journal of Information Technology Applications and Management
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• v.13 no.4
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• pp.13-39
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• 2006

The primary purpose of this study is to examine the interaction effects of organizational characteristics as contextual variables on the relationship between relational exchange characteristics and ASP service performance. The effect of relational exchange characteristics on ASP service performance has been also investigated. For this purposes, we developed a research model based on the literature reviews of ASP services, relational exchange theory, and contingency theory. A total of 106 usable survey responses from companies using ASP services has been analyzed in the study. The findings indicate that (1) flexibility and partnership had a positive influence upon noneconomic profit, (2) information sharing had a positive influence upon economic profit, (3) organizational size and IS maturity had a partial moderating effect on the relationship between relational exchange characteristics and ASP service performance, and (4) the subgroup analysis, conducted to determine the exact nature of interaction effect, reveals that the relationship between relational exchange characteristics and noneconomic profit is significantly stronger with a high level of organizational size than with a low level, and that the relationship between relational exchange characteristics and economic profit is significantly stronger with a low level of IS maturity than with a high level.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.529-540
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• 2018

Sand dam is a flow barrier commonly built on small or medium size sandy rivers to accumulate sand and store excess water for later use or increase the water table. The effectiveness of sand dam in increasing the water table and the amount of extractable groundwater is tested using numerical models. Two models are developed to test the hypothesis. The first model is to simulate the groundwater flow in a pseudo-natural aquifer system with the hydraulically connected river. The second model, a modified version of the first model, is constructed with a sand dam, which raises the riverbed by 2 m. In both models, the effect of groundwater abstraction is tested by varying the pumping rate. As the model results show the groundwater after the construction of the sand dam has increased significantly and the amount of extractable groundwater is also increased by many folds. Most importantly, in the second model, unlike the pseudo-natural aquifer system, the groundwater abstraction does not have a significant effect on the water table.

• The Journal of Engineering Geology
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• v.25 no.3
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• pp.369-376
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• 2015

Numerical models simulating groundwater flow are often used to estimate groundwater discharge into a tunnel. In designing numerical models, the grid size should be carefully considered to ensure that groundwater discharge is accurately predicted. However, several recent studies have employed various grid sizes without providing an adequate explanation for their choice. This paper suggests the optimal grid size based on a comparison of numerical models with analytical solutions. Discrepancies between numerical and analytical solutions result from the effect of model boundaries as well as the grid size. By nullifying boundary effects, the errors solely associated with the grid size could be analyzed. The optimal grid size yielding accurate numerical solutions was thus derived. The suggested relationship between tunnel radius and optimal grid size is analogous to the relationship between the equivalent well block radius and grid size.

• Fisheries and Aquatic Sciences
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• v.11 no.1
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• pp.61-69
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• 2008

Using empirical data of fish performance and physiological limits as well as physical stimuli and environmental data, a cod-end selectivity model based on a chaotic behavior model using the psycho-hydraulic wheel and neural-network approach was established to predict fish escape or herding responses in trawl and cod-end designs. Fish responses in the cod-end were categorized as escape or herding reactions based on their relative positions and reactions to the net wall. Fish movements were regulated by three factors: escape time, a visual looming effect, and an index of body girth-mesh size. The model was applied to haddock in a North Sea bottom trawl including frequencies of movement components, swimming speed, angular velocity, distance to net wall, and the caught-fish ratio; simulation results were similar to field observations. The ratio of retained fish in the cod-end was limited to 37-95% by optomotor coefficient values of 0.3-1.0 and to 13-67% by looming coefficient values of 0.1-1.0. The selectivity curves generated by this model were sensitive to changes in mesh size, towing speed, mesh type, and mesh shape.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.320-325
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• 2010

A multiphase CFD analysis is performed to investigate the effect of near-wall grid for simulating a subcooled boiling flow in vertical tube. The multiphase flow model used in this CFD analysis is the two-fluid model in which liquid(water) and vapor(steam) are considered as continuous and dispersed fluids, respectively. A wall boiling model is also used to simulate the subcooled boiling heat transfer at the heated wall boundary. The diameter and heated length of tube are 0.0154 m and 2 m, respectively. The system pressure in tube is 4.5 MPa and the inlet subcooling is 60 K. The near-wall grid size in the non-dimensional wall unit ($y_{w}^{+}$) was examined from 64 to 172 at the outlet boundary. The CFD calculations predicted the void distributions as well as the liquid and wall temperatures in tube. The predicted axial variations of the void fraction and the wall temperature are compared with the measured ones. The CFD prediction of the wall temperature is shown to slightly depend on the near-wall grid size but the axial void prediction has somewhat large dependency. The CFD prediction was found to show a better agreement with the measured one for the large near-wall grid, e.g., $y_{w}^{+}$ > 100.