• 제목/요약/키워드: specific performance

검색결과 5,402건 처리시간 0.03초

소수력발전입지의 수계별 설계변수 특성(I) (Design Parameters of Small Hydro Power Sites for River Systems(I))

  • 박완순;이철형
    • 한국태양에너지학회 논문집
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    • 제30권4호
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    • pp.86-91
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    • 2010
  • The characteristics of hydrologic design parameters for small hydro power(SHP) sites located in four major river systems have been studied. The model, which can predict flow duration characteristic of stream, was developed to analyze the variation of inflow. And another model to predict hydrologic performance for SHP plants is established. The results from hydrologic performance analysis for SHP sites located on five major river systems based on the models developed in this study show that the specific design flowrate and specific output of SHP site have large difference between the river systems. The load factor, however, have small difference compared with specific design flowrate and specific output for all river systems. Also, it was found that the models developed in this study can be used to predict the primary design specifications of SSHP plants effectively.

Numerical Design and Performance Prediction of Low Specific Speed Centrifugal Pump Impeller

  • Yongxue, Zhang;Xin, Zhou;Zhongli, Ji;Cuiwei, Jiang
    • International Journal of Fluid Machinery and Systems
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    • 제4권1호
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    • pp.133-139
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    • 2011
  • In this paper, Based on Two-dimensional Flow Theory, adopting quasi-orthogonal method and point-by-point integration method to design the impeller of the low specific speed centrifugal pump by code, and using RANS (Reynolds Averaged N-S) Equation with a standard k-${\varepsilon}$ two-equation turbulence model and log-law wall function to solve 3D turbulent flow field in the impeller of the low specific speed pump. An analysis of the influences of the blade profile on velocity distributions, pressure distributions and pump performance and the investigation of the flow regulation pattern in the impeller of the centrifugal pump are presented. And the result shows that this method can be used as a new way in low speed centrifugal pump impeller design.

A General Performance of PSS-LCDs

  • Mochizuki, Akihiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.91-96
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    • 2005
  • In this paper, a general performance of the PSS-LCD or Polarization Shielded Smectic Liquid Crystal Display is discussed. This smectic base LCD does not use any spontaneous polarization, but uses induced polarization just same with current nematic base LCDs. Specific initial molecular alignment as well as specific cell design realizes extremely fast optical response speed with native wide viewing angle. Moreover, this performance is provided by full compatible electronics for current conventional LCDs. A general performance of the PSS-LCD is introduced here.

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인적자본은 언제 기업의 혁신성과를 향상시킬 수 있는가?: 국제화 경험의 조절효과를 중심으로 (When Does Human Capital Facilitate the Corporate Innovation Performance?: The Moderating Effect of International Experience)

  • 권순환;권종욱;신만수
    • 아태비즈니스연구
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    • 제11권3호
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    • pp.47-61
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    • 2020
  • Purpose - This study investigates the relationship between firm-specific, general human capital and corporate innovation performance. Also, we examine when this relationship is more salient. Design/methodology/approach - We collected 1,195 survey data related to a sample of corporate innovation performance and human capital from 1) Korea Research for Vocational Education and Training and 2) NICE information service in Korea. In order to examine the corporate innovation performance, we use the ordered logit model. Findings - First, we find robust supports for our hypothesis that firm-specific and general human capital increase corporate innovation performance. Second, the effect of general human capital on corporate innovation performance is stronger when this relationship is combined with the firm international experience. Research implications or Originality - By integrating the human capital theory and corporate innovation literature, we propose that firm-specific and general human capital are the important determinant of innovation performance. The firm-specific human capital may increase innovation efficiencies. Also, retaining higher-quality general human capital is considered as an important innovation strategy since firms with higher-quality general human capital make greater innovation performance. Further, we show that the firm international experience is the crucial boundary condition. As a firm's experience in internationalization increases, firms can enhance the opportunities to develop new products by combining the skills and knowledge derived from general human capital with the experience gained through internationalization.

Muscle-Specific Creatine Kinase Gene Polymorphisms in Korean Elite Athletes

  • Kang, Byung-Yong;Kang, Chin-Yang;Lee, Kang-Oh
    • Toxicological Research
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    • 제19권2호
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    • pp.115-121
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    • 2003
  • In view of the importance of muscle-specific creatine kinase (CKMM) gene as a genetic factor for athletic performance, we investigate the relationship between elite athletic performance and two restriction fragment length polymorphisms (Ncol and Taql RFLPs) in the CKMM gene. Genomic DNA was extracted from white blood cells of 98 unrelated male Korean elite athletes and 04 sedentary controls, respectively. Two genetic polymorphisms in the CKMM gene were detected by the polymerase chain reaction and the digestion with restriction endonucleases, Ncol and Taql, respectively. There were no significant associations between two genetic polymorphisms in the CKMM gene and elite athletic performance or clinical parameters in our subjects. Therefore, these findings suggest that two genetic polymorphisms in the CKMM gene may not be useful as genetic markers to predict the athletic performance in male Koreans.

OECD 농업환경지표와 정책연계 방안 (Directions for Linkages between Policy Measures and the OECD Agricultural Environmental Indicators)

  • 김창길;김태영
    • 한국환경농학회지
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    • 제24권3호
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    • pp.303-313
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    • 2005
  • Agricultural environmental indicators (AEIs) are useful tool for evaluating environmental performance induced by agri-environmental policy measures. General and specific criteria have been set to assess the linkages between policy measures and environmental states. In addition, a number of specific AEIs such as nutrient balance indicators and farm management indicators have been posit to review environmental performance associated with agri-environmental policy measures. The proposed environmental subjects encompass soil quality, qualities of underground and surface water, water resource preservation, species and genetic diversity, diversity for wildlife habitats, and agricultural landscapes. The developed AEIs may contribute to establishment or adjustment of environmental targets and ex-ante or ex-post evaluation for environmental performance associated with policy measures. In addition, the AEIs may be useful to consider introduction of new agri-environmental measures and enhance policy efficiency by assessing environmental performance, considering specific locality, and harmonizing support measures.

단순언어장애 아동과 정상 아동의 구문적 난이도에 따른 문장따라말하기; 수행력 및 명료도 비교 (The Effect of Syntactic Complexity on Sentence Repetition Performance and Intelligibility between Specific Language Impairment and Normal Children.)

  • 안지숙;김영태
    • 음성과학
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    • 제7권3호
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    • pp.249-262
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    • 2000
  • The purpose of the present study was to investigate the effect of syntactic complexity (sentence length and sentence structure) on sentence repetition performance and intelligibility between specific language impairment (SLI) and normal children. Thirteen SLI children and twenty-six normal children, matched by 3 years of language, participated in this study. The sentence repetition performance of the subjects were analyzed based on the sentence length (3-word simple sentences and 5-word simple sentences) and sentence structure (5-word simple sentences, 5-word conjoined complex sentences, and 5-word embedded complex sentences). The results of this study indicated the sentence structure influenced sentence repetition performance and intelligibility of SLI children only. The implication of these findings were discussed.

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흡기 조성 변화가 디젤기관의 성능에 미치는 영향 (Effects of Intake Gas Compositions on the Performance of Diesel Engine)

  • 김세원;이재규
    • 한국자동차공학회논문집
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    • 제2권2호
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    • pp.49-58
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    • 1994
  • A study on the performance of a Diesel engine with various intake gas compositions other than that of air are performed experimentally. In this study, the concentrations of each of oxygen, nitorgen, carbon dioxide, and argon are changed and their effects on the performance of the engine are investigated parametrically. The experiments are performed at constant engine speed condition, and main measured parameters are cylinder pressure, intake gas compositions, fuel consumption rate. Increase of oxygen concentration up to 24% improved the performance of the engine generally. The adverse effect was observed when the oxygen concentration was increased over 24%. Increase of carbon dioxide concentration degraded the performance of the engine, mainly due to the lower specific heat ratio of carbon dioxide. Adding argon gas to the intake gas improved the overall performance. Finally, it is found that two most influencing factors affecting the performance of the Diesel engine in this study of intake gas composition variation are ignition delay and specific heat ratio of the intake gas.

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B2B 기업의 시장지향성이 관계특유투자와 지각된 경제적 성과에 미치는 영향 (A Study on the Effect of Market Orientation on Relationship Specific Investment and Performance)

  • 김광명;박주식
    • 경영과정보연구
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    • 제38권4호
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    • pp.113-136
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    • 2019
  • 기업성과는 모든 기업 활동의 궁극적인 산출물로서 경영학 분야별로 성과에 미치는 영향요인에 관한 연구가 진행되어 왔으며 본 연구에서는 마케팅 분야에서 가장 많이 언급되고 있는 영향요인 중 하나인 시장지향성을 중심으로 B2B 기업의 성과에 관한 영향요인들을 규명하고 그 관계를 실증적으로 검증하였다. 관련 문헌고찰을 토대로 가설을 설정하였으며, 가설검증을 위해 울산지역 내 B2B 기반 기업들의 대상으로 설문을 수집하였으며 수집된 자료 중 최종 288부의 설문지가 분석에 사용되었다. 분석결과, 시장지향성의 하위 3개 요인 중 시장정보창출과 시장정보반응은 B2B 기업 간 관계에서의 파트너십 형성을 위한 관계특유투자에 긍정적인 영향을 미치는 것으로 나타났으며 시장정보확산을 유의한 영향을 미치지 않는 것으로 나타났다. 한편 시장지향성의 하위 3개 요인 모두 경제적 성과에는 직접적으로 영향을 미치지 않는 것으로 나타났고, 관계특유투자는 경제적 성과에 유의한 영향을 미치는 것으로 나타나 시장지향성과 경제적 성과를 관계특유투자가 매개하고 있음을 확인하였다. 끝으로 시장지향성 3위 요인 중 시장정보창출과 관계특유투자의 관계는 의존성에 의해 부(-)의 방향으로 조절되는 것으로 나타났다. 이러한 분석결과에 기반하여 연구의 학문적, 실무적 시사점을 제시하였으며, 연구의 한계점과 향후 연구방향도 제시하였다.

극저비속도 영역 마이크로 횡류수차의 성능 및 내부유동 수치해석적 연구 (CFD Analysis on the Performance and Internal Flow of a Micro Cross-Flow Hydro Turbine in the Range of Very Low Specific Speed)

  • 최영도;손성우
    • 한국유체기계학회 논문집
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    • 제15권6호
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    • pp.25-30
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    • 2012
  • Renewable energy has been interested because of fluctuation of oil price, depletion of fossil fuel resources and environmental impact. Amongst renewable energy resources, hydropower is most reliable and cost effective way. In this study, to develop a new type of micro hydro turbine which can be operated in the range of very low specific speed, a cross-flow hydro turbine with simple structure is proposed. The turbine is designed to be used at the very low specific speed range of hydropower resources, such as very high-head and considerably small-flow rate water resources. CFD analysis on the performance and internal flow characteristics of the turbine is conducted to obtain a practical data for the new design method of the turbine. Results show that optimized arrangement of guide vane angle and inner guide angle can give contribution to the turbine performance improvement.