• Fire Science and Engineering
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• v.18 no.1
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• pp.42-48
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• 2004

The deterministic modeling techniques like Zone model and Field model are mainly used for thermal distribution and smoke flow at fire case in multi use facilities. While Zone model analyse fire simulation by dividing spaces by 2 section, the Field model dividing many cells. However, the difficultly follows to prove efficiency between the two models when it applys. Therefore new modeling development is required which in closes to real situation by verify number algorithm and related data for fire modeling. The paper analyses the efficiency of two different fire modeling at interior spaces of multiplex cinema theater. It is found that the zone model for average distribution and the field model for detail space phenomenon are relevant to apply. Also, Filed model is useful to the result that fire analysis and position of detector and review for smoke control system.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.52
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• pp.97-118
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• 2011

85% of South Korea's gross domestic product(GDP) depends on trade. Exports amount in 2011 exceeds $ 5,000Billion. Korea is expected to achieve $ 1 trillion in total trade volume and will become finally the ninth in the world. We do not have a lot of natural resources and are bound to export the finished products to pursue economic development. In other words, trade sector is very essential for Korea to continue economic growth. The department of trade in universities have brought up the concerned students serving for trade sectors. Currently, "half-price tuition" in universities has become very controversial issue in Korea so this paper studies the efficiency of "the Department" because the universities may reconsider the adjustment of tuition fee, if they can enhance the efficiency level. DEA model is used for the analysis. As a result, 8 DMUs like KAN1, KEI5, BAE10 etc. show relatively higher efficiency levels.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.6
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• pp.1539-1544
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• 1995

Copper blow test to measure the forging capability of 35 ton counterblow hammer and upset of plasticine on the model hammer to investigate the change of the blow efficiency during the forging process have been performed together with finite element analyses of these experiments. The blow efficiency of the hammer has been found to be dependent on the friction and on the contact area between the die and the workpiece. The effects of the volume and the aspect ratio of the billet have not been found. Inferring from the experimental results and Schey's empirical formula on the forging load, we expect that the efficiency also varies with the flow stress of the workpiece material and with the shape complexity of the forging product.

• Ocean and Polar Research
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• v.30 no.4
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• pp.445-451
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• 2008

This paper examines measures of technical efficiency in off-shore fishery based on a frontier production function model of the Cobb-Douglas type. Technical efficiency ranges between 57.13 and 98.62 percent. The results suggest that the highest TE in the industry is the trawl. Also, this analysis shows that Busan's Danish seine fishery has a maximum TE. Angling in Gangwon has a minimum TE. Empirical measures of technical efficiency in this study can be useful in analyzing the potential effects of policies designed to deal with the current fishery industry.

• The Korean Journal of Health Service Management
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• v.7 no.3
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• pp.225-235
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• 2013

This study purposed to analyze the productivity of regional medical capacity in attracting medical tourist between 2009 and 2011. Data envelopment analysis (DEA) and Malmquist productivity index (MPI) were applied to test the productivity and changes in study periods. The DEA model included a number of doctors, nurses, and beds as input factors, and a number of inpatient and outpatient, and hospital income as output factors. The result of the study were as follow. Jeju had efficiency value of 1 for three years. Seoul, Busan, Daegu, Daejeon, Ulsan, Gyeonggi, Gangwon, Jeonnam, Gyeongbuk, and Gyeongnam showed an increasing trend of efficiency value over three years. Seoul had the efficiency value, 1, in 2011. But, Incheon, Gwangju showed decreasing efficiency score during the study period. MPI showed overall productivity decrease during the period. Further studies will be needed by collecting more time-series data.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1169-1171
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• 2001

Synchronous reluctance motors(SynRM) for the application such as an electric vehicle, compressor drives of air conditioner and machine tool spindle drives require a wide field-weakening speed range. In order to improve the efficiency performance in such applications, this paper has examined the loss and the efficiency characteristics of SynRM mainly in the field-weakening speed region over the base speed. The control strategy in order to offer a efficiency optimization operation is shown and the copper and iron losses driven the equivalent circuit model of the machine is minimized. The usefulness of the proposed efficiency optimization control is verified through the SynRM durve system.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.137-142
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• 2008

The purpose of the present study is to investigate the convective heat transfer characteristics and the validity of fin efficiency of the circular finned-tube heat exchanger by using commercial CFD code. The heat transfer coefficient obtained by using the laminar model was 22% overestimated to the experimental data. The fin surface temperature compared with the experimental data measured by the liquid crystal method. The fin efficiency by the present numerical experiment, defined as normalized and averaged fin surface temperature, was greater than the theoretical fin efficiency and the difference is increased at high value of the factor m.

• Journal of the Korean Society of Food Culture
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• v.31 no.4
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• pp.339-347
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• 2016

With the interest on operational efficiency due to the rapid growth of food material distribution industry and food service industry, the study adopts DEA (Data Envelopment Analysis) model and examines to measure the technological, pure technical and scale efficiency those companies engaging in the food material distribution and food service business. As a result of analysis, the companies operating integrated business have relatively higher efficiency than those operating only food material distribution or food service companies while the result indicates that three efficiencies don't have significant difference depending on whether affiliated companies or not. In the results from the measuring by DEA.

• Journal of Korea Foundry Society
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• v.33 no.6
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• pp.248-253
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• 2013

To add alloying elements into a pure copper melt, the wire-feeding efficiency of cored (alloy containing) wire was evaluated using a commercial, computational fluid-dynamics program. The model design was based on an industrial-scale production line. The variables calculated included wire feed rate, melt temperature, wire diameter, melt flow rate and wire temperature. Efficiency was evaluated after a series of calculations based on the penetration depth of the alloy-wire into the molten copper bath. Of the five variables investigated, the wire feed rate and wire diameter were the most influential factors affecting the feeding efficiency of the cored-wire.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.3
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• pp.296-303
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• 2014

The Axiom propeller is a unique 3 bladed propeller and it enables to generate the same amount of thrust going ahead as it does going astern because of its 's' type skew-symmetric blade section. A earlier variant of the design (Axiom I propeller) performed a low propeller efficiency, maximum 35 % efficiency, and further blade outline design was carried out to achieve a higher efficiency. The optimized new blade outline (Axiom II propeller) has more conventional Kaplan geometry shape than Axiom I propeller. Model tests of open water performance and propeller cavitation for both propellers were conducted at Emerson Cavitation Tunnel in order to compare their performances. Experiment results revealed that Axiom II propeller provides a maximum 53 % efficiency and provides better efficiency and cavitation performance over the Axiom I propeller under similar conditions.