Evaluating the operational efficiency of electric vehicle charging stations (EVCSs) is important to understand charging network evolution and the charging behavior of electric vehicle users. However, aggregation of efficiency performance metrics poses a significant challenge to practitioners and researchers. In general, the operational efficiency of EVCSs can be measured as a complicated function of various factors with multiple criteria. Such a complex aspect of managing EVCSs becomes one of the challenging issues to measure their operational efficiency. Considering the difficulty in the efficiency measurement, this paper suggests a way to measure the operational efficiency of EVCSs based on data envelopment analysis (DEA). The DEA model is formulated as constant returns of output-oriented model with five types of inputs, four of them are the numbers of floating population and nearby charging stations, distance of nearby charging stations and traffic volume as desirable inputs and the other is the traffic speed in congestion as undesirable one. Meanwhile, the output is given by the charging frequency of EVCSs in a day. Using real-world data obtained from reliable sources, we suggest operational efficiencies of EVCSs in Seoul and discuss implications on the development of electric vehicle charging network. The result of efficiency measurement shows that most of EVCSs in Seoul are inefficient, while some districts (Nowon-gu, Dongdaemun-gu, Dongjak-gu, Songpa-gu, Guro-gu) have relatively more efficient EVCSs than the others.

드론은 현재 산업의 각 분야에서 사용되고 있으며, 농업분야에서도 활발히 사용되고 있다. 특히, 초고 령 사회에 진입한 농촌과 농업분야에서 드론은 매우 효율적인 방제장비로 각광받고 있다. 드론방제기 는 운용비용이 다른 방제기에 비해서 매우 낮으며 구입비용 또한 그리 높지 않다. 한 단위의 방제면적 을 방제하기 위하여 투입되는 구입비용과 운용비용을 모두 고려하였을 때 가장 효율적인 방제기는 고 정익방제기와 드론이라 불리는 멀티콥터형 방제기이다. 고정익방제기에 소요되는 높은 운용비용과 탑 승조종사의 인건비를 고려한다면 우리나라에서 현실적으로 효율적인 방제기라 볼 수 없으며, 조종사가 탑승하지 않는 드론방제기가 매우 효율적인 방제기라고 할 수 있다. 현재 농업분야에서 방제작업에 활 발히 쓰이고 있는 드론방제기는 높은 비용효율성으로 인하여 많은 농민들에게 선호되는 방제기로 선택 되고 있다.

This study collected and analyzed the fishing process of existing fishing boat and newly built fishing boat by using the video observation methods to understand the improvement of fishing operation efficiency and safety according to the scale change of coastal composite fishing boat. The fishing operation efficiency was calculated by analyzing the frequency of movement, the movement distance and the moving time per basket used in the fishing process to derive the improvement of the newly built fishing boat compared to the existing fishing boat. It was confirmed that the mean frequency of movements decreased to 13.9%, the average moving time decreased to 21.8%, the mean movement distance increased to 20.5% and the movement through the top of gunwale did not occur. Movement of frequency, increased and time according to the fishing operation were directly affected by the width of side passages and the presence or absence of walking obstruction such as bulwark stay, hatch coaming and fishing gears on deck. The results of this study are expected to be used as basic data for redesigning into a safe and efficient coastal composite fishing boat in the future.

During the last quarter-century, globalisation processes affected changes in the world economy in the form of intensifying competition in the international and internal markets. The result is the creation of a global marketplace that is mostly indifferent to national borders and governmental influences. This development has generated widespread interest in competitiveness. Competitiveness affects international relations, especially nowadays, given the changing position of the global leaders and the growth of new economic powers such as China. China has come a long way and has the opportunity to be a global leader in several required fields that will be the cornerstones of global growth in the next decades. Led by China, emerging economies are increasing their share in the worldwide economy and intensifying competition in nearly all sectors. It creates new threats and challenges for players in the global economy, and growing competitiveness must be efficient. The article evaluates the Chinese competitiveness in comparison with the World Trade Organization members by the Data Envelopment Analysis in the pre-in-post crisis period and considering the Fourth Industrial Revolution shifting humanity into a new phase.

The production of abalone seed has grown and been specialized since the 2000s with the growth of the abalone farming industry. Despite the increase in the production of abalone seeds, the sales volume of abalone seeds remained flat and competition among producers increased. This paper will analyze the management efficiency of abalone seed production fishery to diagnose the management status and improve the abalone seed production efficiency. In addition, this study is the result of the basic research on the abalone seed industry and it is meaningful to prepare a platform for further research since the management status survey and the management efficiency survey of abalone seed production fishery have not been conducted until now. The data on the farmed fish prices of abalone seeds were collected from surveys of sample fish as part of the fish seed observation project conducted by the Fisheries Outlook Center (FOC) of Korea Maritime and Fisheries Development Institute (KMI). Management efficiency analysis utilizes DEA (Data Envelopment Analysis) model. The DEA model was analyzed by classifying into CCR (Super-CCR), BCC, and SBM (Super-SBM) models according to the assumptions taking into account the characteristics of the industry. The slack considered in the SBM model was judged as possible decreases in input variables and increase in output variables. The average efficiency from the CCR model was analyzed to be 69%. The BCC model was classified into input and output orientations, and the average efficiency was 79% and 75%, respectively. There were seven production fisheries with an SE value of 1 or more, which remained unchanged in terms of size and could be benchmarked. The average efficiency of the SBM model was 59% for CRS and 66% for VRS. Under the VRS assumptions, the variable increase/decrease efficiency analysis shows that labor costs can be reduced by 37.3%, facility capacity by 18.8%, and operating costs by 8.5%. In order to improve management efficiency, Wando needs to reduce labor and management costs. In Jindo region, sales increase as well as labor cost reduction is urgent. In other regions, reduced facilities and increased sales are recommended.

농업은 고용, 식량 및 생계를 목적으로 하는 카메룬 경제의 중심이다. 그러나 카메룬 농업은 낮은 생산성, 비효율성 및 수입에 의존하여 전염병에 시달리고 있다. 이러한 이유로 본 연구는 카메룬 북서부 지역의 쌀 농가의 기술적 효율성을 조사했다. 구조화된 설문지와 인터뷰를 사용하여 144명의 농부로부터 데이터를 수집했다. 기술 통계 및 확률적 프런티어 분석을 사용하여 데이터를 분석하였다. 확률적 프런티어 분석의 결과는 분산 매개 변수 (시그마 제곱 및 감마)가 통계적으로 유의하다는 것을 보여준다. 농장 규모, 비료, 노동 및 제초제의 계수는 긍정적이고 중요했다. 평균 기술 효율성 수준이 84%로 나타낸 것은 가용 자원을 효율적으로 활용한다면 쌀 농민의 기술 효율성을 16%로 증가할 수 있다. 비효율성 모델은 신용 액세스가 기술적 비효율 성과 부정적인 관련이 있는 중요한 요소임을 보여준다. 이 결과는 농민에게 생산성을 향상시키기 위해 신용을 제공하려는 정부의 노력 (SEMRY, UNVDA, ARFIC및 2세대 농업)과 일치한다.

Protecting and preserving the natural and environmental treasures of Jeju Island is, eventually, the collective responsibility of the people of Jeju, all levels of the government, corporate and the environmental NGO sectors. Jeju Island has a vibrant environmental NGO sector with about 80 NGOs providing a variety of active environmental services. All efforts and services to conserve the environment of Jeju Island for the benefits of future generations need to be galvanized within the overarching environmental governance where all three sectors actively participate and make collective decisions within the three key elements of sustainable development: people, planet & profit. The key ingredient for promoting networking and collaborative opportunities between environmental NGOs, government entities and corporations is to improve their trust on one another. Given the current status of environmental NGOs - governments - corporations relations, it will take time to develop such trust, but if small measures are undertaken, mutual understanding & respect between the leaders of NGOs, government and corporations will grow and eventually result in mutual trust.

본 연구는 국내 가선집재 작업 현장 실태에 대한 사례 조사를 통해 작업의 생산성에 영향을 미치는 집재 작업의 설계와 가선 설치의 공학적 문제점을 파악하고, 그로 인해 손실되는 생산성과 증가되는 비용을 분석하기 위한 목적으로 수행되었다. 분석 결과, 가선집재 설계 시 현장의 지형적 입지여건과 공학적 안전성이 충분히 고려되지 않아 대부분 가선의 처짐(deflection)을 확보하지 못하는 것으로 나타났 다. 이로 인해 시간 당 생산성이 최대 65%까지 감소하고, 집재비용이 2배 이상 증가되어 전반적인 작업의 효율성이 떨어지는 것으로 나타났다. 따라서 앞으로 국내에서 가선집재 작업이 확대되기 위해서는 작업 안전과 효율을 확보할 수 있는 가선의 설치와 장비의 운용, 불필요한 생산비용을 최소화할 수 있 는 현장 기술의 보급이 필요하다.

본 연구의 목적은 농가의 사회·경제적 특성을 조사하여 대상 지역 쌀 생산의 기술적 효율성 수준을 분석하는 것이다. 또한 이 연구에서는 캄보디아의 쌀 생산성 수준에 영향을 미치는 요인들을 확인하고자 하였다. 이 연구에 사용된 정보는 2016년에 캄보디아 남부에 위치 하는 다케오주의 트람꺽군과 키리웡군에서 무작위로 선택된 80개의 농가를 면접 조사한 자료이다. 농가의 사회·경제적 특성을 조사하기 위하여 기술 관련 통계 자료가 활용되었다. 또한 inputorientation data envelopment analysis는 기술적 효율성 점수를 추정하는데 사용되었다. 더불어 Tobit regression은 쌀 생산의 효율성 수준에 영향을 미치는 요인을 확인하는데 사용되었다. 연구 결과에 따르면 연구 결과에 따르면 연구 분야 농가의 평균 기술 효율은 0.67인 반면, 쌀 생산업자들은 같은 생산 수준을 유지하면서도 투입 비용을 33% 절감할 수 있는 것으로 나타났다. 다케오주의 뜨람꺽군 및 키리웡군의 쌀 생산의 효율성 수준에 영향을 미치는 네 가지 요인이 발견되었다. 토빗 회귀분석 결과, 가장의 성별, 가장의 주요 직업, 쌀의 재배 횟수를 포함한 요인들이 기술적 효율성에 긍정적인 영향을 미치는 반면 심어진 종자와 품종은 기술적 효율성에 부정적인 영향을 미치는 것으로 추정되었다. 쌀 생산 규모의 효율성은 0.80로 분석되었으며, 이는 농민들이 적정 규모에 가깝게 운영 하고 있음을 나타낸다. 이는 생산관련 비효율의 원인이 투입 자원의 잘못된 배분이나 부적절한 사용으로 인한 것임을 의미 한다.

대규모 유한요소 모델을 빠르게 해석하기는 위해서 병렬 희소 솔버를 필수적으로 적용해야 한다. 이논문에서는 미세하게 변화하는 시스템 행렬을 대상으로 연속적으로 해를 구해야 하는 문제에서 효율적으로 적용가능한 반복-직접 희소 솔버 조합 기법을 소개한다. 반복-직접 희소 솔버 조합 기법은 병렬 희소 솔버 패키지인 PARDISO에 제안 및 구현된 기법으로 새롭게 행렬값이 갱신된 선형 시스템의 해를 구할 때 이전 선형 시스템에 적용된 직접 희소 솔버의 행렬 분해(factorization) 결과를 Krylov 반복 희소 솔버의 preconditioner로 활용하는 방법을 의미한다. PARDISO에서는 미리 설정된 반복 회수까지 해가 수렴하지 않으면 직접 희소 솔버로 해를 구하며, 이후 이어지는 갱신된 선형 시스템의 해를 구할 때는 최종적으로 사용 된 직법 희소 솔버의 행렬 분해 결과를 preconditioner로 사용한다. 이 연구에서는 첫 번째 Krylov 반복 단계에서 소요되는 시간을 동적으로 계산하여 최대 반복 회수를 설정하는 기법을 제안하였으며, 주파수 영역 해석에 적용하여 그 효과를 검증 하였다.

The purpose of this study is to analyze the efficiencies of project management offices in large information system construction projects using the data envelopment analysis. In addition, we tried to estimate the confidence interval of those efficiencies using bootstrap DEA to give a statistical meaning. The efficiency by the CCR model is analyzed as eight project management offices are fully efficient and 22 project management offices are inefficient. On the other hand, there are 15 project management offices are fully efficient, but 15 project management offices are inefficient in the BCC model. As the result of the scale efficiencies, of the inefficient project management offices, 13 project management offices are inefficient in scale. It is possible to eliminate the inefficiency in the CCR model by improving their project performances. And, the nine project management offices showed that the inefficiency was due to pure technical efficiency, and these companies should look for various improvements such as improvement of project execution system and project management process. In order that the inefficient project management offices be efficient, it is analyzed that more efforts must be made for on-budget and on-time as a result of examining the potential improvement potentials of inefficient project management offices.

The purpose of this study is to improve effectiveness of Korea’s Official Development Assistance (ODA) provided to developing countries. To do this, we analyze the efficiency of ODA provided to 38 recipient countries by Korea through data envelope analysis method. The effects of four factors including population, GDP, economic decline and poverty, and external intervention on efficiency are also investigated by utilizing tobit regression analysis. As a result of the DEA efficiency analysis, it is found that the average efficiency score of the total is about 59%. By region, the average efficiency score of Asia, Africa, Central and South America, and the East and CIS (Commonwealth of Independent States) are about 42%, 68%, 70%, and 74%, respectively. It indicates that the Asian countries are inefficient compared to countries of the other regions. It is also found that factors of population, GDP, economic decline and poverty, and external intervention have statistically significant effects on efficiency at 0.01 significance level. In the case of the population, the higher the population of the recipient country, the more negative (-) effect is on the efficiency. The other factors such as GDP, economic decline and poverty, and external intervention have positive effects on the efficiency.

PURPOSES: This study evaluates the efficiency of snow removal operation resources using data envelopment analysis (DEA). The results of this study can help decision-making strategies, especially for resource allocation for snow removal works on national highways. METHODS: First, regional road management offices (DMUs) for efficiency evaluation were set up, and a database (for years 2012-2016) for analysis was formed. Second, DEA was carried out by selecting input and output variables based on the constructed database. Lastly, based on the results of the DEA, the efficiency of each regional road management office was evaluated. In addition, the potential for future improvement was determined. RESULTS: The results showed that there was a large variation in efficiency of snow removal operation resources by regional offices. CONCLUSIONS: The results of this study imply that the evaluation of efficiency for snow removal operation resources is important when decisions related to snow-removal strategies are made by road management offices.