• 수산해양기술연구
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• 제32권3호
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• pp.257-265
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• 1996

The combined hydroacoustic and bottom trawl surveys were conducted in the Cheju southeastern area by the training ship "KAYA" belong to Pukyong National University in July 1995 and the traning ship "NAGASAKI MARl]" belong to Nagasaki University in April 1994, respectively. The main purpose of the investigations was to provide the basic data for the management and the biomass estimation of commercially important demersal fish stocks in this area. Fish samples were collected by bottom trawling from 10 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches were examined. The fish school target strength for demersal fish aggregations was related to the catchability of trawl net with a 90 mm mesh codend. The most abundant species in the 1995 trawl stations were Japanese flying squid, sword tip squid and red horsehead and that of the 1994 trawl stations Japanese flying squid and blackmouth goosefish. The average weight per cubic meter of trawl catches collected by bottom trawling in the Cheju southeastern area were $1.0791{\times}lO^-4$kg/$m^3$ in the 1994 survey area and $1.3636{\times}lO^-4$kg/$m^3$ in the 1995 survey area, respectively. The catch data by cover net suggest that the efficiency of trawl net could affect the weight normalized target strength values for demersal fish aggregations. That is, the average target strength per unit of weight dropped from - 33.1 dB/kg using the total catch by codend and cover net to - 30.5 dB/kg using only the catch data by codend, and a change of2.6 dB/kg was observed.ange of2.6 dB/kg was observed.

• 한국전기전자재료학회논문지
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• 제36권2호
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• pp.136-142
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• 2023

In the past, the efficiency of solar cells had been increased in order to increase the efficiency of solar modules. However, in recent years, in order to increase output in the solar industry and market, the competitiveness of solar cells based on large-area solar cells and multi-bus bar has been increasing. Multi-busbar solar module is a technology to reduce power loss by increasing the number and width of the front busbar of the solar cell and reducing the current value delivered by the busbar by half through half-cutting. In the case of the existing M2 (156.75×156.75 mm²) solar cell, even with a half-cut, power loss could be sufficiently reduced, but as the area of the solar cell is enlarged to more than M6 (166×166 mm²), the need for more divisions emerged. This affected not only solar cells but also inverters required for module array configuration. Therefore, in this study, the electrical characteristics of a large-area solar cell and after division were extracted using Griddler simulation. The output characteristics of the module were predicted by applying the solar cell parameters after division to PSPice, and a guideline for the large-area solar module design was presented according to the number of divisions of the large-area solar cell.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.193-205
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• 2022

Based on the results of this study, we presented the following policy recommendations to improve the efficiency of operation and management of public cremation facilities. First, we findings the cremation number of all public cremation facilities in Gyeonggi-do increased from 39,918 people before the opening of public cremation facilities in Hwaseong to 55,642 people after the opening, showing a high rate of increase of 15,724 people(39.4%). Therefore, in order to increase the cremation ratio, the policy of expanding the supply of public cremation facilities should be actively pursued. Second, in this study we compared to before the opening of public cremation facilities in Hwaseong City, the ratio of cremation number the jurisdiction area of all public cremation facilities in Gyeonggi-do using the E-Haneul Funeral Information System increased by 19.0% from 35.9% to 54.9% after the opening, whereas it was analyzed that the outside of the jurisdiction area decreased by 19.0% from 64.1% to 45.1%. Therefore, in order to improve the convenience of citizens using the jurisdiction area, priority should be given to the promotion of policies for the establishment of public cremation facilities by local governments that do not have public cremation facilities. Third, through we research it is analyzed that the cremation ratio of the jurisdiction area of the public cremation facilities in Hwaseong City, which was jointly installed by six local governments located in Gyeonggi-do, was 92.4%, indicating that the ratio proportion of cremation number in the area is very high. Therefore, in order to improve the efficiency of the operation of public cremation facilities, the promotion of policies for joint installation and operation of public cremation facilities should be encouraged.

• 산업경영시스템학회지
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• 제40권2호
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• pp.31-40
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• 2017

In this paper, we compared the efficiencies of national R&D investments between NT (Nanotechnology) areas in terms of papers, patents, and commercializations, and found ways to improve the efficiencies of national R&D investments for each NT area. This is in response to huge R&D investments government has made recently in NT areas. Here, we collected data on investments, papers, patents, and commercializations for the R&D projects in NT areas through National Science & Technology Information Service. Based on the data, we analyzed the investment and performances (papers, patents, and commercializations) for each NT area, calculated the efficiency for each NT area, and compared the efficiencies between NT areas. Next, using cluster analysis, we identified several NT areas with similar characteristics in terms of paper efficiency, patent efficiency and commercialization efficiency. Finally, we derived implications for the efficiency enhancement for each grouping. The cluster analysis showed that there could be two groups, one being low in terms of technological outcome (papers and patents) efficiencies and high in terms of commercialization efficiencies, while the other being high in terms of technological outcome (papers and patents) efficiencies and low in terms of commercialization efficiencies. Therefore, the strategy for one group calls for support for technology transfer or technology introduction from other R&D performers and grant of guidance for improving R&D performers' commercialization ability to other R&D performers while the strategy for the other group calls for R&D support for transfer of technology to other R&D performers, activation of technology transfer and support for commercialization of R&D performers.

• 한국항해항만학회지
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• 제39권6호
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• pp.507-514
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• 2015

본 연구는 항만 물류배후단지에 입주하여 운영하는 입주업체들의 효율성을 분석하는 것을 연구의 목적으로 하였다. 인천항과 부산신항 항만 물류배후단지 13개 입주기업을 효율성 분석대상으로 하였으며, 투입변수는 투자액, 면적, 종업원 수를 사용하였고, 산출변수는 물동량과 매출액을 선정하였다. 효율성 분석방법으로는 전통적인 CCR 모형과 BCC 모형을 적용하고 이들의 한계점을 극복하기 위해 초효율성 모형과 Super-SBM 모형을 적용하였다. 초효율성 모형의 분석결과, 평균값은 0.777, 표준편차는 0.541로 나타나 각 기업 간 효율성 점수 차이는 33% 정도 존재하는 것으로 분석되었다. Super-SBM 모형의 분석결과, 평균값은 0.649, 표준편차는 0.489로 초효율성 모형에서 여분을 고려할 경우 기업 간 효율성 점수 평균이 약 13% 정도 감소한 것으로 나타났다. 이러한 감소의 의미는 비방사형 여분이 존재하는 DMU의 효율성 점수하락이 평균 13% 정도 됨을 의미한다. 투입요소의 비효율성 분석결과 면적 -33%, 투자액 -33%에 비해 종업원 수의 비효율성이 -45%로 가장 큰 것으로 분석되었다.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.1002-1009
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• 2011

The light extraction efficiency of top-emitting organic light-emitting diode (OLED) was improved by insertion of corrugation patterns between indium tin oxide and organic layers. The corrugation patterns was fabricated by nanosphere lithography, which could form a self-assembled particle monolayer over a large area. The electrical and optical properties for the OLED devices fabricated by vacuum evaporation, were investigated. We have demonstrated the enhancement of the power efficiency of corrugated OLED. As a result, the power efficiency of the corrugated OLED was found to be more than 42%.

• 대한기계학회논문집
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• 제19권6호
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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.

• 한국태양에너지학회 논문집
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• 제25권3호
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• pp.47-52
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• 2005

Normally if sunlight is directed on a solar cell without any increasing in temperature, the amount of absorption energy per unit area of each cell is increasing. In a silicon solar cell. however, cell conversion efficiency decreases with the increase of temperature. Therefore, to maintain cell conversion efficiency under normal condition, it is necessary to keep the cell at operating temperature. We tried to design and make new hybrid panel with cooling system to prevent increasing of temperature on cell, collect and use thermal energy more effectively. We compared performance of this new hybrid panel with current thermal panel. We also evaluated conversion efficiency, thermal capacity and confirmed cooling effects from thermal absorption efficiency.

• 한국기계가공학회지
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• 제19권5호
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• pp.8-13
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• 2020

In this paper, the electric vehicle (EV) and internal combustion engine vehicle (ICEV) are compared for different driving cases. The EV exhibits a lower powertrain efficiency when driven on the aggressive driving cycle than when driven on the moderate cycle. In particular, EV powertrain efficiency is low when the battery state of charge (SOC) is low, but ICEV efficiency increases when the driving cycle changes from the moderate cycle to the aggressive cycle. Based on these results, attempts can be made to increase EV powertrain efficiency. EV charging before the battery power drops to a low charging state can reduce energy consumption by 2.7% for an urban area. Furthermore, ECO driving has a more significant effect on EVs than on ICEVs.

• Advances in Computational Design
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• 제5권3호
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• pp.261-276
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• 2020

The reasonable layout of vacuum cleaner can effectively improve the collection efficiency of iron filings generated in the process of steel production. Therefore, in this study, the CFD-DEM coupling model and two-fluid model are used to calculate the iron filings collection efficiency of vacuum cleaner with different inclination/cross-sectional area, pressure drop and inlet angle. The results are as follows: The CFD-DEM coupling method can truly reflect the motion mode of iron filings in pneumatic conveying. Considering the instability and the decline of the growth rate of iron filings collection efficiency caused by high pressure drop, the layout of 75° inclination is suggested, and the optimal pressure drop is 100Pa. The optimal simulation results based on two-fluid model show that when the inlet angle and pressure drop are in the range of 45°~65° and 70Pa~100Pa, larger mass flow rate of iron filings can be obtained. It is hoped that the simulation results can offer some suggestion to the layout of vacuum cleaner in the rolling mill.