• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.641-652
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• 2000

The effect of block arrangement has been investigated on the particle deposition in the specified collecting cell of two-stage electrostatic precipitator by numerical analysis. Recirculation zone existed at the downstream of the block in the collecting cell, and the particles entering the recirculation zone were deposited on the collecting plate. Particle trajectory and deposition had considerably different phenomenon according to electrostatic and inertial effect, which depended on inlet mean velocity, electrostatic number, and particle diameter in the collecting cell. The total collection efficiency reached a minimum value through an interaction of electrostatic and inertial effect. In the computational domain, total collection efficiency for the case of two blocks in the computational domain was more than that of one block at the relative small electrostatic number. However as the block distance and inertial effect increased, the difference between the collection efficiency of two cases decreased. In the range of relatively small particle size total collection efficiency was always superior to particle collection efficiency that was predicted by Deutsch equation.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.91-96
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• 2005

TPM(Total Productive Management) that is enforcing introducing more than $80\%$ in domestic manufacturing industry is using total plant efficiency by the evaluation index, and as a result, can see a lot of examples that plant productivity is increased. This study's purpose centers total productive management activities that is management system for total plant efficiency's maximization, plant information system that total productive management activities factor that is enforcing in manufacturing industry can develop evaluation model that can evaluate qualitative activities by quantitative activities in process that maximize total plant efficiency wishes to do design.

• Journal of the Korea Safety Management & Science
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• v.7 no.2
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• pp.1-12
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• 2005

TPM(Total Productive Management) that is enforcing introducing more than $80\%$ in domestic manufacturing industry is using total plant efficiency by the evaluation index, and as a result, can see a lot of examples that plant productivity is increased. This study's purpose centers total productive management activities that is management system for total plant efficiency's maximization, plant information system that total productive management activities factor that is enforcing in manufacturing industry can develop evaluation model that can evaluate qualitative activities by quantitative activities in process that maximize total plant efficiency wishes to do design.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.8
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• pp.99-108
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• 2022

This study aims to examine the influence of capital structure on the business efficiency of joint stock commercial banks listed on the Vietnamese stock market. The article uses data collected from the financial statements of 15 prominent joint-stock commercial banks out of 27 joint-stock commercial banks listed in Vietnam from 2011 to 2021. The research uses E-view software in quantitative analysis to build regression models to determine the relationship and the impact of capital structure factors on the business efficiency of listed joint stock commercial banks. Research results show that ROA is affected by 2 variables of capital structure. It is the sum of customer deposits to total assets and total liabilities to total equity. Total debt to total equity and total customer deposits to total assets both have a negative effect on ROA. For the regression results of ROA with all control variables, the control variables have a positive relationship with the dependent variable. The article has provided recommendations based on the research findings to determine the proper capital structure. Managers must solve the outstanding amount of mobilized capital in previous years, combined with the bad debt handling activities that have arisen.

• Journal of Korea Port Economic Association
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• v.24 no.4
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• pp.47-70
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• 2008

The purpose of this study is to estimate total factor productivity(TFP) growth by stochastic frontier function and to grasp contributing factors of its growth rate by decomposing the total factor productivity into efficiency change, technical progress, scale change, and allocation change. Annual growth rate of total factor productivity for 1990-2003 is 0.019 (1.9%), higher than that of overall industry (0.010). The main component of TFP growth is not efficiency change but technical progress. Contributing factors of total factor productivity growth are change of allocation efficiency in port industry, technical progress in sea-transportation industry, and change of scale efficiency in transportation-equipment industry. The change of total factor productivity shows a decreasing trend since late in the 1990s. The annual technical efficiency of port-logistics industry is less than that of overall industry. Capital elasticity for output (0.391) is higher than labor elasticity (0.227), but scale economy of port-logistics industry is 0.618, which is far from optimal scale economy.

• The Journal of the Korea Contents Association
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• v.20 no.2
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• pp.27-35
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• 2020

The Korean semiconductor industry is the top export item, and its technological prowess is also higher than that of its competitors. However, the technology gap with rivals will narrow. And the semiconductor industry is facing difficulties due to trade friction. Therefore, semiconductor firms should be more efficient in their production. we study analyzes the efficiency semiconductor firms using DEA model. We evaluate the CCR, BBC efficiency and RTS(return to scale) of 30 Korean semiconductor firms. There are a total of 13 efficient DMUs with a BCC of 1. There are a total of 6 efficient DMUs with a CCR of 1. A total of 10 DMUs were IRS in Scale Efficiency and a total of 9 DMUs were CRS in Scale Efficiency and a total of 11 DMUs were DRS in Scale Efficiency. We also suggest the semiconductor firms which can be benchmarked based on analyzed information.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.151-158
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• 2019

The high-technological in the electric and electronic industries is recognized in overseas markets as well. However, the competition for technologies in these industries is increasing. Therefore, electric and electronic firms should be more efficient in their production. so, This paper analyzes the efficiency of High-growth Electrical and Electronics firms using DEA model. We evaluate the CCR, BBC efficiency and RTS(return to scale) of 20 Korean high-growth Electrical and Electronics firms. There are a total of 12 efficient DMUs with a BCC of 1. There are a total of 4 efficient DMUs with a CCR of 1. A total of 11 DMUs were IRS in Scale Efficiency and a total of 6 DMUs were CRS in Scale Efficiency and a total of 3 DMUs were DRS in Scale Efficiency. We also suggest the Electrical and Electronics firms which can be benchmarked based on analyzed information.

• Journal of Korean Society on Water Environment
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• v.24 no.4
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• pp.499-503
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• 2008

In order to control the non-point source pollution, a vegetative filter strips (VFS) was set up and the site-monitoring was performed. The objective of this study is to investigate the influence of the plant coverage on treatment efficiency of total nitrogen (T-N) and total phosphorus (T-P) using vegetative filter strips. According to the results, it seemed that the treatment efficiencies of T-N and T-P were closely related with the plant coverage ratio. The results showed that treatment efficiency of T-P average 50% at higher than 50% of the plant coverage and 20~23% at lower than 50% of the plant coverage. Also, the treatment efficiency of T-N increased with the increase of the plant coverage ratio.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.699-704
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• 1999

The Photodegradation efficient of total organic compounds in the drinking water has been studied using the methods of photocatalytic reaction and laser beam irradation. The results are summarized as follows; 1. The photodegradation efficiency of total organic compounds shows as $50\%\;to\;80\%$ as within one hour and after this the efficiency is decreased slowly. 2. The photodegradation efficiency of total organic compounds shows as 65 to $90\%$ within 3.3min. when Nd : YAG beam is irradiated to the water layer. 3. An excellent observation of the organic compound removal efficiency gives revealed in that case of the longest wavelength of 532nm is irradiated among the three kinds of laser beam sources of 532nm, 355nm and 266nm. 4. The organic compound removal efficiency shows high in the case of UV beam irradiation in the thin layer of water. However the efficiency is not depended on the thickness of water layer severely. 5. The removal efficiency of the organic compounds in the direct irradiation shows higher than the indirect irradiation in the case of UV beam, but the efficiency is not depended on the direction of irradiation in the case of Nd : YAG beam irradiation.

• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.240-247
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• 1998

Leakage vortices formed near blade tip causes an increase of total pressure loss near casing endwall region and as a result, the efficiency of rotor decreases. The reduction of rotor efficiency is related to the size of tip clearance. In this study, the three-dimensional flowfields in an axial flow rotor were calculated with varying tip clearance under various flow rates, and the numerical results were compared with experimental ones. The effects of tip clearance and attack angle on the leakage vortex and overall performance, and the less distributions were investigated through numerical calculations. In this study, tip leakage flow rate and total pressure loss by tip clearance were evaluated using numerical results and aprroximate equations were presented to evaluate the reduction of rotor efficiency by tip leakage flow.