• 제목/요약/키워드: efficiency of scale

검색결과 3,102건 처리시간 0.035초

경지정리 사업이 농업기계화에 미치는 영향 (Effect of Land Consolidation on Agricultural Mechanization)

  • 고학균;조성인;이중용;이정엽
    • Journal of Biosystems Engineering
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    • 제24권6호
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    • pp.493-500
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    • 1999
  • In 1990's, two types of land consolidation has been widely carried out to enforce competativeness of rice production in Korea. One is so called large-scale land consolidation for resizing paddy field and farm road, the other is general land consolidation for changing both size and shape of field, water channel and farm road. This study was conducted to evaluate how much effect on fm mechanization the land consolidation had. To evaluate the influence of the land consolidation, theoretical analysis and surveys were accomplished. Land consolidation was analyzed to increase field efficiency by 180 to 670% depending on the type of land consolidation and machine selection. Also, land consolidation brought increment of real working time ratio by reducing traveling time on farm road. Trends of large scale mechanization and increment of custom work were observed to be accelerated by land consolidation. It also gave effect on the pattern of machine troubles. Farmers were conscious of the influence of land consolidation on machine utilization, however, in plains level of satisfaction was shown to be low.

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GPS/INS 항측에 의한 대축척 수치지형도 제작의 효율성 평가 (Evaluation of Large Scale Digital Mapping by Photogrammetry with GPS/INS)

  • 위광재;서용운;양인태;최윤수;이자영
    • 대한공간정보학회지
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    • 제16권1호
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    • pp.43-48
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    • 2008
  • 본 연구에서는 GPS/INS 항공사진측량 기술을 이용하여 1/1,000 수준의 대축척 수치지형도를 제작하고 전통적인 항공사진측량과의 차이점, 즉 정확도, 경제성 등을 평가하여 GPS/INS 항측의 효율성을 평가하였다. 연구결과, 지상 기준점측량 공정에서 약 40%의 작업량 절감효과가 발생한 것으로 나타났으며, 작업지역의 크기에 따른 작업효율성은 1/5,000 항측의 경우 전통적인 방법과 동일한 정확도를 유지하는 것을 기준으로 할 때 대략 10모델과 20모델 블록에서는 55%, 30모델 블록의 경우 60%의 지상기준점이 감소함을 확인하였다.

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Determinants of Retail Banking Efficiency: A Case of Vietcombank Branches in the Mekong-Delta Region

  • LE, Thi Thu Diem
    • The Journal of Asian Finance, Economics and Business
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    • 제7권7호
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    • pp.439-451
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    • 2020
  • This study focused on researching the factors affecting retail banking efficiency of Vietcombank branches in the Mekong-Delta region. By collecting data from financial statements from 15 branches of VCB in the Mekong-Delta Region between 2015 and 2018, the paper applies DEA estimation to measure the effectiveness of retail banking activities and uses the Tobit regression model to identify factors affecting retail banking efficiency. The results demonstrate that the retail banking efficiency of branches averaged 52.5% during the period. The rating result shows the branches in An Giang, Can Tho, Dong Thap, Kien Giang, Long An, Phu Quoc and Tra Noc rank at the top technical efficiency. In group of medium efficiency, there are branches in Soc Trang, Tien Giang and Vinh Long. In the category of the poor efficiency are the branches in Bac Lieu, Ben Tre, Ca Mau, Chau Doc and Tra Vinh. The results also show that bank scale-related factors, capital adequacy, credit quality, time specific and region impact significantly the retail banking efficiency. The research not, only contributes to enriching the empirical research method but also is significant for the management activities in business developing strategies, improving the operational efficiency of Vietcombank in the region.

간호원의 주관적 지각과 직무효율성간의 상관연구 (A Correlation Study on Nurses′Subjective Perception and Their Effectiveness)

  • 정현숙
    • 대한간호학회지
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    • 제3권2호
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    • pp.101-109
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    • 1973
  • The present study in the view of humanistic psychology was attempted to seek the purpose of study, the relationship between nurses′working efficiency that measured by an observational working efficiency scale and their subjective perception. "Perceptual orientation scale"(Choy, Chung Hoon 1971) was administered to 100 nurses during the Period of May to July 1972, and the relationship with their ratings by their supervising head nurses. Educational background, ages, and their lengths of caller were compared with their subjective perceptions. All the relationship were calculated by the method of chi-squares and correlational coefficients. The results of this study are summarized as follow: 1. There is no significant relationship between nurses′subjective perceptions and their working ratings. 2. There is significant relationship between nurses′subjective perceptions and their educational backgrounds. 3. There is no significant relationship between nurses′subjective perceptions and their lengths of career. 4. There is no significant relationship between nurses′subjective perceptions and their ages. The results of the present study are interpreted to the sampled research group of this study and are not to be extended to any other groups.

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Lab-scale 고온전기분해 수소생산시스템의 장기운전 성능평가 (Long-Term Performance of Lab-Scale High Temperature Electrolysis(HTE) System for Hydrogen Production)

  • 최미화;최진혁;이태희;유영성;고재화
    • 한국수소및신에너지학회논문집
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    • 제22권5호
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    • pp.641-648
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    • 2011
  • KEPRI (KEPCO Research Institute) designed and operated the lab-scale high temperature electrolysis (HTE) system for hydrogen production with $10{\times}10cm^2$ 5-cell stack at $750^{\circ}C$. The electrolysis cell consists of Ni-YSZ steam/hydrogen electrode, YSZ electrolyte and LSCF based perovskite as air side electrode. The active area of one cell is 92.16 $cm^2$. The hydrogen production system was operated for 2664 hours and the performance of electrolysis stack was measured by means of current variation with from 6 A to 28 A. The maximum hydrogen production rate and current efficiency was 47.33 NL/hr and 80.90% at 28 A, respectively. As the applied current increased, hydrogen production rate, current efficiency and the degradation rate of stack were increased respectively. From the result of stack performance, optimum operation current of this system was 24 A, considering current efficiencies and cell degradations.

White ledger의 초음파 탈묵 : 파일롯 규모 적용 실험 (Deinking of White Ledger with Ultrasonic Wave : Pilot Scale Trial)

  • 원종명
    • 펄프종이기술
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    • 제40권2호
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    • pp.16-22
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    • 2008
  • The pilot scale ultrasonic deinking was carried out in order to confirm the commercialization possibility of ultrasonic deinking. White ledger was used as a raw material and the results were compared to the results obtained from the conventional deinking. The fraction of smaller ink particle was increased and the improved ink removal efficiency was also obtained by the ultrasonic treatment. The brightness and breaking length of ultrasonic deinked pulp were superior to those of the conventional deinked pulp. Most interesting findings in this study were that the significant improvement in effluent quality and the reduction of chemicals and energy cost were obtained by the ultrasonic deinking.

Decomposition of Odorous Gases in a Pilot-scale Nonthermal Plasma Reactor

  • Hwang, Yoon-Ho;Jo, Young-Min
    • Journal of Korean Society for Atmospheric Environment
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    • 제21권E2호
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    • pp.57-65
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    • 2005
  • An experimental study was performed on the decomposition of gaseous ammonia and two selected volatile organic compounds (VOCs: toluene and acetone) in a combined nonthermal plasma reactor with corona and glow discharges. A lab pilot scale reactor (206 liter) equipped with a high electric power pack was used to determine the decomposition efficiency in relation with the inlet concentration and applied voltage. Three different types of discharging electrode such as wired rack, wire strings for corona discharge, and thin plate for glow discharge were put in order in the reactor. While decomposition of ammonia decreased with an increase in the initial concentration, acetone showed an opposite result. In the case of toluene however no explicit tendency was found in toluene and aceton. Negative discharge resulted in high decomposition efficiency than the positive one for all gases. A better removal of gas phase element could be achieved when fume dust were present simultaneously.

원자력 이용 고체산화물 고온전기분해 수소 및 합성가스 생산시스템의 열역학적 효율 분석 연구 (A Study on Thermodynamic Efficiency for HTSE Hydrogen and Synthesis Gas Production System using Nuclear Plant)

  • 윤덕주;고재화
    • 한국수소및신에너지학회논문집
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    • 제20권5호
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    • pp.416-423
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    • 2009
  • High-temperature steam electrolysis (HTSE) using solid oxide cell is a challenging method for highly efficient large-scale hydrogen production as a reversible process of solid oxide fuel cell (SOFC). The overall efficiency of the HTSE hydrogen and synthesis gas production system was analyzed thermo-electrochemically. A thermo-electrochemical model for the hydrogen and synthesis gas production system with solid oxide electrolysis cell (SOEC) and very high temperature gas-cooled reactor (VHTR) was established. Sensitivity analyses with regard to the system were performed to investigate the quantitative effects of key parameters on the overall efficiency of the production system. The overall efficiency with SOEC and VHTR was expected to reach a maximum of 58% for the hydrogen production system and to 62% for synthesis gas production system by improving electrical efficiency, steam utilization rate, waste heat recovery rate, electrolysis efficiency, and thermal efficiency. Therefore, overall efficiency of the synthesis production system has higher efficiency than that of the hydrogen production system.

그리드 컴퓨팅에서 유효자원 동적 재배치 기반 작업 스케줄링 모델 (Dynamic Available-Resource Reallocation based Job Scheduling Model in Grid Computing)

  • 김재권;이종식
    • 한국시뮬레이션학회논문지
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    • 제21권2호
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    • pp.59-67
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    • 2012
  • 그리드 컴퓨팅은 하나의 대용량 작업을 처리하도록 물리 자원을 구성하고 있지만 최근에는 데이터의 급속한 증가로 인해서 복수개의 작업을 처리하는 방법이 필요하다. 일반적으로 대용량 작업을 요청하면 각 물리 자원들이 작업을 분할하게 되며, 자원의 성능과 거리에 따라 처리 시간이 다르다. 성능에 따라 먼저 완료된 유효자원은 어떠한 작업도 하지 않으며, 모든 작업이 끝났을 경우에 다음 작업을 처리한다. 이에 본 논문에서는 먼저 처리가 완료된 자원을 다른 작업에 할당할 수 있는 동적 자원 재배치 스케줄링 모델(DRRSM: Dynamic Resource Reallocation Scheduling Model)을 제안한다. DRRSM은 먼저 처리가 완료된 자원을 다른 작업에 자원의 성능과 거리에 따라 작업을 재배치시키는 방법이다. DRRSM은 여러 개의 대용량 작업을 처리하는데 효과적이다.

Comparative Analysis of 10 MW Superconducting Wind Power Generators with Three-phase and Nine-phase Armature Windings

  • Kim, Taewon;Woo, Sang-Kyun;Sung, Hae-Jin
    • KEPCO Journal on Electric Power and Energy
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    • 제5권4호
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    • pp.343-347
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    • 2019
  • When referring to weight, volume, and efficiency, a SuperConducting Synchronous Generator (SCSG) is definitely superior to conventional generators as a large-scale wind power generation system. The SCSG is connected to a full power converter that transmits the energy from the SCSG to the power grid. To reduce the current stress and system cost, the SCSG which has nine-phase armature windings with three converters is used. This paper deals with a comparative analysis of 10 MW superconducting wind power generators with three-phase and nine-phase armature windings. The stator windings of SCSGs are of various types. Using the finite element method, SCSGs are analyzed and compared in terms of the weight and volume of SCSGs, the total length of the superconducting wire, harmonics, torque performance, and efficiency. The analyzed results will be effectively utilized to design large-scale superconducting generators for wind power generation systems.