• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.263-271
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• 2024

This paper analysis of spatial differences in the efficiency of regional industrial enterprises in China from 2011 to 2021. The efficiency analysis uses the DEA-CCR model. The input variables for efficiency analysis are total assets and annual average employees, and the output variables are revenue from principal business and total profits. Using trend surface analysis and gravity center model, to analysis the spatial differences of efficiency in different regions. From the results of the gravity center model, the coordinates of the gravity center of China's regional industrial enterprise efficiency in 2011 are 112.303°E & 34.239°N, and 2021 are 111.753°E & 33.791°N, which indicates that the gravity center of the efficiency of China's regional industrial enterprises in the 2011-2021 period generally moves to the southwest. From the results of the trend surface analysis, the efficiency of industrial enterprises in China's regional industrial enterprises appears to show spatial differences in both the eastwest and the northsouth directions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.870-873
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• 2013

본 논문에서는 이동 에드 혹 네트워크(Mobile Ad-hoc network: MANET)에서의 상황인식 기반의 스케쥴링 기법인 DDV(Dynamic Direction Vector)-hop 알고리즘을 제안한다. 기존 MANET에서는 노드의 이동성으로 인한 동적 네트워크 토폴리지, 네트워크 확장성 결여의 대한 취약성을 지니고 있다. 또한 노드들의 이동성에 따라 에너지 소모율이 다르며, 에너지 소모율을 최소화하는 라우팅 기법을 선택하는 것이 중요하다. 따라서 본 논문에서는 계층적 클러스터 단위의 동적이 토폴로지에서 노드가 이동하는 방향성 및 시간에 따른 노드의 이동 속성 정보를 고려하여 클러스터를 생성 및 유지하는 DDV-hop알고리즘을 제안한다. 또한 주어진 노드의 위치정보를 이용하여 토폴로지를 형성함에 있어 보다 에너지 효율적인 경로를 탐색하여 최적화된 경로를 제공함에 연구의 목적이 있다. 주어진 모의실험환경에서 노드의 방향성 및 시간에 따른 이동성을 반영함으로써 에너지 효율적인 클러스터링 및 라우팅 경로 알고리즘이 제공되어 네트워크의 최적화된 에너지 소모 결과를 보여주었다.

• Survey Research
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• v.6 no.1
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• pp.39-62
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• 2005

In this paper we investigate some concepts frequently called in sample surveys such as 'representative of sample' as well as 'consistency', 'unbiasedness', and 'efficiency' in estimation. The first is strongly related with sampling procedure including coverage rate of survey population, response rate in establishment survey, and recruit rate of final samples. The others, however, are concerned with both sampling design and corresponding estimators simultaneously. Whereas both consistency and unbiasedness are based on the representative sample, efficiency does not depend on the representative sample. The representative of sample can be increased by raising the rate of coverage, response and recruit as well. Consistency may be investigated according to variables of interest and auxiliary variables. The well-known raing-ratio weighting method is a method to increase consistency of auxiliary variables by means of matching population size in each cell. Efficiency is not directly related with the representative of sample, and allocation methods such as proportional and Neyman allocation in stratified sampling and post-stratification are all methods to increase the efficiency of estimation under the condition of satisfying the representative of sample.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.895-906
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• 2018

The improvement project for school zone in Korea is occurring mostly in kindergartens and elementary schools in which children are mainly active, and is being promoted as part of measures to prevent children's traffic accidents. However, since the study on the essential installation facilities and proper level of safety facilities for School zone is lacking, this study relatively evaluated the efficiency of safety facility installation using DEA (Data Envelope Analysis) and suggested improvement plan. We built the facilities and incident data for 28 school zones in Hwaseong City. Six major facilities (Raised intersection, Raised crosswalk, Protective fence, Skid Proof, Speed hump, Speed cameras) that have proven to be effective in the preceding research were analyzed as input factors. As a result of the analysis, only 12 out of 28 showed efficiency and 16 out of efficiency. Effective groups of school zones were found to have fewer installed Protective fences, Skid Proof, and Speed cameras installations than school zones classified as ineffective groups. Protective fences were found to be efficient even if only 47% of the total extension of the school zone was installed, and the number of slip prevention facilities was 8.7 per square km. The number of subjects to be compared is 28, so this study is limited to use as a relative efficiency evaluation index, and it can be grouped into nationwide units and efficiency evaluation can be done for each group.

• Journal of Korea Technology Innovation Society
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• v.14 no.2
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• pp.205-222
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• 2011

The Korean government continuously increases the R&D investment in order to pursue an economic growth through technological innovation. Hence, the intensity of governmental R&D has increased rapidly. However, the whole amount of the R&D investment is still small compared to developed countries. And the type of R&D policies is more and more changing from the catch-up model to the technology-driven model. Therefore, there is a growing interest in the efficiency of public R&D investment. Hence, many studies on the efficiency of R&D investment have been researched. This study estimated the efficiency of governmental R&D programs considering the technological outcomes, e.g. theses, patents and so on, using DEA(Data Envelopment Analysis) with data of S&T investment and outcomes from NTIS(National S&D Information Service). In addition, we used the Mann-Whitney Test to investigate the characteristics of governmental R&D investment.

• Journal of Korea Technology Innovation Society
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• v.21 no.4
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• pp.1345-1365
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• 2018

Following principal-agent relationship between government and funding agency effects on efficiency and management of project, this paper suppose that project management cost rate variable on outsourcing and administration of institution, applies multiple regression analysis and logit analysis by using factors that procurement status of institutional operating expenses and each subordinates scale (Budget, subject number) and method (Top-down/Bottom-up), not a total amount, for examining factors following project efficiency analysis and way of commission. The major variables which effect on efficiency of institution are management cost scale (0.36), institutional operating expenses ratio (-0.47), way of outsourcing, the factors that affect way of outsourcing are portion of project management cost (-38.5) and institutional operating expenses rate (-11.7). This means both legal and financial stability are necessary and it is avoidable moral hazard and adverse selection on principal-agent problem.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.115-117
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• 2005

버퍼의 효율적인 관리는 시스템의 성능과 밀접한 관련성을 가지고 있다. 따라서, 최근까지 다양한 버퍼 관리 기법들이 제안되었다. 그러나, 지금까지 알려진 기법들의 대부분은 시간 근접성만을 고려하고 있다. 그러나, 공간 데이터베이스와 같은 환경에서는 시간 근접성뿐 만 아니라, 유사한 위치에 있는 공간 객체들은 서로 같이 접근 될 가능성이 높다는 공간 근접성도 존재한다. 따라서, 본 논문에서는 공간 데이터베이스 환경에서 시간 근접성과 공간 근접성 같이 효과적으로 고려하는 버퍼 관리 기법을 제안하다. 또한, 실험을 통하여 제안 기법의 효율성을 보인다.

• Environmental and Resource Economics Review
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• v.22 no.2
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• pp.329-365
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• 2013

The purpose of this paper is to measure economy and environment efficiencies under fossil fuel and environment regulation by countries for 2000-2009. Distinguishing 83 countries with three groups of OECD, upper-middle, and low countries, we compare four models such as environment oriented, economy-oriented, environment-economy oriented, and two-stage types, which include a desirable output, GDP and an undesirable output, pollutant together in the production possibility set. OECD countries relatively showed high economy efficiency and low environment efficiency, whereas Non-OECD countries showed high environment efficiency and low economy efficiency. OECD countries reported a higher possibility to reduce fossil fuel and $CO_2$ emission.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.667-669
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• 2005

최근 새로운 데이터마이닝 방법인 지도 군집화가 소개되고 있다. 지도 군집화의 목적은 동일한 클래스가 한 군집에 포함되도록 하는 것이다. 지도 군집화는 데이터에 대한 배경 지식을 획득하거나 분류 방법의 성능을 향상시키기 위한 방법으로 사용된다. 그러나 군집화 방법에서 파생된 지도 군집화 역시 군집화 개수 설정 방법에 따라 효율성이 좌우된다. 따라서 클래스 분포에 따라 최적의 지도 군집화 개수를 찾기 위해 진화알고리즘을 적용할 수 있으나, 진화알고리즘은 대용량 데이터를 처리할 경우 수행 시간이 증가되어 효율성이 감소되는 문제가 있다. 본 논문은 지도 군집화보다 강인한인 지도 퍼지 군집화를 효율적으로 생성하기 위해 진화성이 우수한 휴리스틱 분할 진화알고리즘을 제안한다. 휴리스틱 분할 진화알고리즘은 개체를 생성할 때 문제영역의 지식을 반영한 휴리스틱 연산으로 탐색 시간을 단축시키고, 개체 평가 단계에서 전체 데이터 대신 샘플링된 부분 데이터들을 이용하여 진화하는 분할 진화 방법으로 수행 시간을 단축시킴으로써 진화알고리즘의 효율성을 높인다. 또한 효율적으로 개체를 평가하기 위해 지도 퍼지 군집화 알고리즘인 지도 분할 군집화 알고리즘(SPC: supervised partitional clustering)을 제안한다. 제안한 방법은 이차원 실험 데이터에 대해서 정확성과 효율성을 분석하여 그 타당성을 확인한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.147-148
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• 2009

Today, overall industry have been operated on the basis of information technology and have been rised that expectation and investment on it. The distribution industry have growing up importance of integrated material handling information network, the information investment have increase to efficient operate. however, Most efficiency analysis has not been thoroughgoing enough any research that effect on informatization level about the efficiency. The paper describes the evaluation of informatization level of importance is presented to efficient operate in a container terminal, the relative efficiency on informatization level is measured using Data Envelopment Analysis.