• Title/Summary/Keyword: well efficiency

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A Study on Logistical System and Operational Models of Franchise Store Retailing in China

  • Li, Dong-xin;Kang, Tae-won
    • The Korean Journal of Franchise Management
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    • v.3 no.1
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    • pp.130-143
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    • 2012
  • Franchise store retailing is taking on ever greater roles in business and commerce in China. The diverse product range, small-batch order, high frequency and time-specific requirements inherent in retail logistics make it the most complicated of all categories of logistics. In franchise store retailing, expanding business scales make trans-regional development a trend. Without a well-functioning logistic system, the standardized delivery of products would be held back, impacting trans-regional development strategy and operational costs. Therefore, the efficiency of franchise store retailing largely depends on logistical efficiency. The integrated and streamlined management of franchise stores depends in large measure on their logistical centers. As such, logistical centers constitute the key link and bears on core competitiveness in franchise store retailing. This thesis begins with an analysis of the current developments and four basic logistical models of franchise store retailing in China, proceeds to summarize developmental trends as well as focal issues and proposes an efficiency enhancing plan.

A Study on the Selection of Maxium Plant Efficiency through the Performance Test in Snper-Critical Power Plant (초임계압형 화력발전소의 성능시험을 통한 최고효율점 선정에 관한 연구)

  • Kwon, Y.S.;Suh, J.S.
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.402-407
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    • 2003
  • The main reason to select the maxium plant efficiency through the performance test in fossil power plant is to increase the efficiency of power plant as well as saving energy collated with the policy of government. This study is aimed at unerstanding the variantion trend of efficiency and analyzing the efficiency of boiler and turbine through each of the performance test. Ultimately, the maxium efficiency of power plant will be presented in super-critical pressure type power plant.

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Strategies for Improving Potassium Use Efficiency in Plants

  • Shin, Ryoung
    • Molecules and Cells
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    • v.37 no.8
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    • pp.575-584
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    • 2014
  • Potassium is a macronutrient that is crucial for healthy plant growth. Potassium availability, however, is often limited in agricultural fields and thus crop yields and quality are reduced. Therefore, improving the efficiency of potassium uptake and transport, as well as its utilization, in plants is important for agricultural sustainability. This review summarizes the current knowledge on the molecular mechanisms involved in potassium uptake and transport in plants, and the molecular response of plants to different levels of potassium availability. Based on this information, four strategies for improving potassium use efficiency in plants are proposed; 1) increased root volume, 2) increasing efficiency of potassium uptake from the soil and translocation in planta, 3) increasing mobility of potassium in soil, and 4) molecular breeding new varieties with greater potassium efficiency through marker assisted selection which will require identification and utilization of potassium associated quantitative trait loci.

A Field Verification Study on the Effect of Filter Layers on Groundwater Level Drop Characteristics, Permeability, Optimum Yield and Well Efficiency in the Unconfined Aquifer Well for Riverbank Filtration Intake (강변여과수 취수를 위한 충적우물에서 필터층이 수위강하특성, 투수성, 적정양수량 및 우물효율에 미치는 영향에 대한 현장실증 연구)

  • Song, Jae-Yong;Lee, Sang-Moo;Kang, Byeong-Cheon;Lee, Geun-Chun;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.29 no.4
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    • pp.509-529
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    • 2019
  • This study performs to evaluate the role of filter material at alluvial well for intake of riverbank filtration and the applicability and improvement effect of dual filter well. To achieve this objective, dual filter intake well and single filter intake well were installed with different filter conditions at riverbank free surface aquifer in soil layer then we evaluated filter material condition, permeability, optimum yield and well efficiency according to yield in drawdown test. As a results, we assumed forming dual filter layer minimizes sudden speed changes at boundary between aquifer and filter layer by cushioning of groundwater flow. This suppresses warm current then intake groundwater efficiently, therefore it seems decreasing peripheral groundwater level changes in spite of higher intake water amount than single filter intake well. Furthermore, we confirmed by test, installing dual filter improves permeability, optimum yield and well efficiency. The result will be used by combining with former study to set up standard of design/construction of dual filter intake well at alluvial aquifer layer. Furthermore, we expect this result will be used to prove application effect of dual filter intake well compared to single filter one and radial collector well which are mainly applied on riverbank filtration.

Design and performance research of a mixed-flow submersible deep well pump

  • Zhang, Qihua;Xu, Yuanhui;Cao, Li;Shi, Weidong;Lu, Weigang
    • International Journal of Fluid Machinery and Systems
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    • v.9 no.3
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    • pp.256-264
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    • 2016
  • To meet the demand of higher handling capacity, a mixed-flow submersible deep well pump was designed and tested. The main hydraulic components are made of plastics, which is free of erosion, light-weight, and environment-friendly. To simplify plastic molding process, and to improve productivity, an axial-radial guide vane was proposed. To clarify its effect on the performance, a radial guide vane and a space guide vane are developed as well. By comparison, the efficiency of the pump equipped with the axial-radial guide vane is higher than the radial guide vane and is lower than the space guide vane, and its high efficiency range is wide. The static pressure recovery of the axial guide vane is a bit lower than the space guide vane, but it is much larger than the radial guide vane. Taking the cost and molding complexity into consideration, the axial-radial guide vane is much economic, promoting its popularity for the moderate and high specific speed submersible deep well pumps.

Photoluminescence study in GaAs/AlGaAs multi-quantum well structure by hydrogen passivation (수소화 처리에 의한 GaAs/AIGaAs 다중양자우물의 PL 연구)

  • Park, Se-Ki;Lee, Cheon;Jung, Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.468-472
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    • 1997
  • The effect of the surface state on the quantum efficiency of underlying GaAs/AlGaAs multi-quantum well(MQW) structures consisting of three GaAs quantum wells with different thickness, is studied by low temperature photoluminescence(PL). The structure was grown by molecular beam epitaxy(MBE) on (100) GaAs substrate. The thickness of three GaAs quantum wells was 3, 6 and 9 nm, respectively. The MQWs were placed apart from 50 nm AlGaAs edge-barriers including two inner-barriers with 15 nm in thickness. The samples used in this study were prepared with different growth temperatures. Particularly, the hydrogen passivation effect to the 9 nm quantum well located at near surface appeared much stronger than any others. Transition energy and optical gain related to the hydrogen passivation effects on the multi-quantum well structure was calculated by transfer matrix method.

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An Approach on Life Cycle Based Efficiency Measurement in Construction Industry (건설 생산의 Life Cycle을 고려한 효율성 측정방안)

  • Jung Soon-Oh;Yoon Su-Won;Chin Sangyoon;Kim Yea-Sang;Park Ji-Hoon
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2004.11a
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    • pp.608-611
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    • 2004
  • Efficiency of the construction process is one of the most important factors to project success. However efficiency is not well defined or measured in construction projects in general. More importantly, efficiency of the construction should be viewed through the life-cycle of the whole production system not in a single phase of the construction process. Therefore, this study defines the concept of efficiency and suggests the efficiency measurement model in construction. As a case study, the suggested model was applied to the curtain wall construction process of the high rise buildings as well.

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Regional Financial Development, Firm Heterogeneity and Investment Efficiency

  • Zhang, Ruonan;Yin, Hong
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.4
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    • pp.73-83
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    • 2018
  • The purpose of this paper is to examine the relationship between regional financial development and corporate investment efficiency as well as the relationship between firm-level characteristics and corporate investment efficiency. Using a large sample of A-listed companies in China from CSMAR database between 2003 and 2016, this paper explores corporate investment efficiency and its influencing factors in emerging market on the basis of heterogeneous stochastic frontier model. The results show that: (1) the average investment efficiency of Chinese listed companies is 74.5%, and the investment efficiency of large enterprises, state-owned enterprises and enterprises with relatively high financial development level is significantly higher; (2) compared with average corporate investment efficiency in the year 2003, the investment efficiency of different types of enterprises in 2016 is significantly higher, and the gap is gradually widening; (3) enterprise heterogeneity namely firm size, nature of property right, and institutional environment reflected by the level of regional financial development indirectly affects corporate investment efficiency by influencing the financing constraints and uncertainty. The findings suggest that to improve corporate investment efficiency in emerging market, financial market should be accelerated, regional balance should be restored and the differences among regions, industries and differences between public and private sectors should be eliminated.

Lagged Unstable Regressor Models and Asymptotic Efficiency of the Ordinary Least Squares Estimator

  • Shin, Dong-Wan;Oh, Man-Suk
    • Journal of the Korean Statistical Society
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    • v.31 no.2
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    • pp.251-259
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    • 2002
  • Lagged regressor models with general stationary errors independent of the regressors are considered. The regressor process is unstable having characteristic roots on the unit circle. If the order of the lag matches the number of roots on the unit circle, the ordinary least squares estimator (OLSE) is asymptotically efficient in that it has the same limiting distribution as the generalized least squares estimator (GLSE) under the same normalization. This result extends the well-known result of Grenander and Rosenblatt (1957) for asymptotic efficiency of the OLSE in deterministic polynomial and/or trigonometric regressor models to a class of models with stochastic regressors.

Space Efficiency and Structural Safety of Eryngii Cultivation House (새송이 버섯 재배사의 공간효율 및 구조안전 검토)

  • Kwon, Jin-Keun;Suh, Won-Myung;Yoon, Yong-Cheol
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.351-354
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    • 2003
  • This study was carried out to set up design criteria of Eryngii cultivation houses. Optimization of lay-out efficiency together with analysis of structural safety were two main tools of approaching toward reasonable models to be developed. Some models tentatively assumed according to the result of field survey and analysis were compared in the aspect of structural safety as well as energy efficiency.

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