• 한국도서관정보학회지
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• 제41권4호
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• pp.35-50
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• 2010

본 연구는 대전 지역에 소재하고 있는 15개 공공도서관을 대상으로 DEA 모형을 사용하여 2008년도 공공도서관의 상대적 효율성을 분석하고 이어서 최근 3년간의 추세변화를 분석하였다. 투입요소로는 직원수, 면적, 장서수가 사용되었으며 산출요소로는 이용책수와 이용자수가 사용되었다. 연구결과, 기술효율성 값의 추세변화를 분석해 보면 3년간 지속적으로 효율성이 개선되었으며, 기술효율성의 개선은 순수 기술효율성과 규모 효율성 둘 다의 개선에 있었다.

• International Journal of Reliability and Applications
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• 제1권2호
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• pp.115-121
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• 2000

The trend change in aging properties, such as failure rate and mean residual life, of a life distribution is important to engineers and reliability analysts. In this paper we develop a test statistic for testing whether or not the failure rate changes its trend using censored data. The asymptotic normality of the test statistics is established. We discuss the efficiency values of loss due to censoring.

• 한국컴퓨터정보학회논문지
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• 제29권1호
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• pp.263-271
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• 2024

본 연구는 2011-2021년을 분서기간으로 중국의 공업기업의 효율성의 지역차이를 분석하고 있다. 효율성은 DEA-CCR 모형을 이용하고 있다. 효율성 분석의 투입변수는 자산총계, 연평균 취업자수를 이용하고 산출변수는 주요영업수입과 이윤총액을 이용하고 있다. 효율성의 지역차이는 Trend Surface 분석방법과 Gravity Center Model을 이용하고 있다. Gravity Center Model의 분석결과에 의하면 2011년의 중국 공업기업의 효율성의 Gravity Center는 112.303°E & 34.239°N이고 2021년은 111.753°E & 33.791°N이다. 이 결과는 2011-2021년 기간 동안 중국 공업기업의 효율성의 Gravity Center는 서남방향으로 이동하고 있다고 해석할 수 있다. Trend Surface 분석결과에 의하면 중국 공업기업의 효율성은 동서 방향과 남북 방향으로 공간차이가 존재하고 있다.

• Journal of East Asia Management
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• 제3권1호
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• pp.11-23
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• 2022

Under the circumstances of China's slower economic growth, the first document ofthe central committee of the CPC continue to focus on "three agricultures" problems, agriculture play a basic role on China's economic. Since 2007, the first document directly stresses the important role of agricultural and fisheries every year. Central Government Working Report of 2015 also stresses that under the new normal of economy, it is important to improve quality and efficiency of agriculture. Agricultural focus going forward will be on improving capacity of competitiveness, innovation and sustainable development.The fishery as an important part of agriculture plays a vital role in the protection of national food security, the prosperity of the rural economy and the optimization of national food structure. However, the situation faced on accelerating the speed of Chinese fisheries is still grim. As an important fishery breeding city in my country, Weihai has achieved remarkable results in the development of fisheries. Based on the input-output indicators of Weihai City from 2010 to 2020, this article uses the DEA model method to conduct a comprehensive analysis of the factors affecting the fishery production efficiency in Weihai City. This paper calculates the two stages of comprehensive efficiency, pure technical efficiency and scale efficiency, and comprehensive compares the two stages. The research results show that: From 2010 to 2020, the average comprehensive technical efficiency of Weihai fishery was 0.928, the average scale efficiency was 0.963, and the average pure technical efficiency was 0.963. The comprehensive technical efficiency of Weihai fishery production showed an upward and downward trend, the pure technical efficiency showed a downward and then upward trend, and the pure technical efficiency showed a fluctuating trend.

• Journal of the Korean Statistical Society
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• 제29권4호
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• pp.455-471
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• 2000

A new method is developed for estimating the mean of a population which has a linear trend. The proposed estimator is based on the balanced systematic sampling method and the concept of interpolation. The efficiency of the proposed method is compared with that of existing methods.

• 한국항만경제학회:학술대회논문집
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• 한국항만경제학회 2006년도 국제학술대회
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• pp.253-276
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• 2006

This paper has shown the trend of competition positioning of 26 Korean ports in 1994, 1999, and 2003 by using BCG matrix which consists of relative market shares, growth rate of cargo handling, and also growth rate and CCR and BCC efficiency scores with scale efficiency scores in the vertical and horizontal axes. The empirical main results are as follows. First, Incheon Port, Pyungtag Port, Gwangyang Port, Busan Port, Pohang Port and Woolsan Port have shown their competitive positioning in terms of market share and growth rate. Second, Pyungtag Port, Wando Port, Tongyoung Port, Gohyun Port, Samcheog Port, and Okgae Port have their competitive positioning in terms of growth rate and scale efficiency scores. The main policy implication of this paper is to emphasize that BCG matrix method using in this paper can give seaport manager the basic information for planning the future port management for enhancing the competitive positioning among Korean seaports.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2019년도 학술발표회
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• pp.149-149
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• 2019

Gross Primary production (GPP) and evapotranspiration (ET) are the two critical components of carbon and water cycle respectively, linking the terrestrial surface and ecosystem with the atmosphere. The ratio between GPP to ET is called ecosystem water use efficiency (EWUE) and its quantification at the forest site helps to understand the impact of climate change due to large scale anthropogenic activities such as deforestation and irrigation. This study was conducted at the FLUXNET forest site CN-Qia (2003-2005) using Community land model (CLM 5.0). We simulated carbon and water fluxes including GPP, ecosystem respiration (ER), and ET using climatic variables as forcing dataset for 30 years (1981-2010). Model results were validated with the FLUXNET tower observations. The correlation showed better performance with values of 0.65, 0.77, and 0.63 for GPP, ER, and ET, respectively. The model underestimated the results with minimum bias of -0.04, -1.67, and -0.40 for GPP, ER, and ET, respectively. Effect of climate 'CLIM' and '$CO_2$' were analyzed based on EWUE and its trend was evaluated in the study period. The positive trend of EWUE was observed in the whole period from 1981-2010, and the trend showed further increase when simulated with rising $CO_2$. The time period were divided into two parts, from 1981-2000 and from 2001 to 2010, to identify the warming effect on EWUE. The first period showed the similar increasing trend of EWUE, but the second period showed slightly decreasing trend. This might be associated with the increase in ET in the wet temperate forest site due to increase in climate warming. Water use efficiency defined by transpiration (TR) (TWUE), and inherent-TR based WUE (IT-WUE) were also discussed. This research provides the evidence to climate warming and emphasized the importance of long term planning for management of water resources and evaporative demand in irrigation, deforestation and other anthropogenic activities.

• 수산경영론집
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• 제43권1호
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• pp.11-18
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• 2012

This study is aimed to estimate a dynamic productive efficiency by vessel of large purse seine fishery and analyze changes of them over times using a window/DEA method. In addition, based on estimation results, it aims to suggest production management implications for an viable development of fisheries. Results indicated that an annual efficiency change of large purse seine fishery was estimated at 0.77 for 2007~2008, 0.83 for 2008~2009, and 0.77 for 2009~2010, showing a decreasing trend. As returns on sales of vessels of large purse seine fishery showed a decreasing trend, the degree of efficiency of a vessel might be closely related to the fishing profitability. The Window/DEA method was used in this study to estimate the efficiencies of vessels for large purse seine fishery. This method is well known and widely used to analyze the dynamic efficiency and it can provide useful implications for management of input factors. As a limitation of this study, it was not able to provide detailed management ways to reduce inefficiencies. However, they can be investigated with data on managerial factor, human factor, distribution factors as a future study.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.97-100
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• 2003

Recently, the generators for wind turbine have been manufactured with high output power such like MW class machine in order to reduce the generation cost and to increase the energy efficiency. At the same time, direct-driven generators for wind turbine have been developed and researched, which have easy maintenance and high efficiency by simplification the system through the removal of the gear box. In this paper, at first, the advantage and disadvantage between the direct-driven generator system and conventional indirect-driven system are compared. And secondly, the permanent magnet generator (PMG) for wind turbine has been rapidly improved to cope with the recent trend which requires the high power output Per one machine and the convenience for maintenance, and the PMG is adequate for direct driven system and suitable for high-efficiency and light weight. So, the characteristics and technical trend of the PMG for wind turbine is examined. At last, a suitable technical trend for development of the permanent magnet generator for wind turbine is proposed.

• Communications for Statistical Applications and Methods
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• 제11권1호
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• pp.1-12
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• 2004

In this paper, Yates' end corrections method is centralized to estimate the mean of a population which has a linear trend in the case of k (the reciprocal of the sampling fraction) even. The efficiency of the resultant method is compared with that of existing methods.