• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.11-19
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• 2013

This study analyzed relative efficiencies of fourteen airports in Korea with radial and non-radial approaches such as DEA(Data Envelopment Analysis) and SBM(Slack Based Measure) from 2004 to 2011. To suggest an improvement scheme for these airports, we analyzed slack airports and compared then with respective reference airports. To measure efficiency, we used the length of runway, the number of employees, and the size of terminal as input factors, and the number of passengers, the amount of cargo, and the number of flights as output factors. The analysis results showed that efficiencies of most airports had been decreasing and that the gap between efficient airports and inefficient airports was widening. Additionally, most airports had much slacks in its terminal size. It meant that they had been operated with a size not proportionate to their demands and that it is a major cause of inefficiency.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.11
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• pp.1383-1389
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• 2011

Gerotor-type volumetric displacement pumps are suitable for oil or water hydraulics. For this reason, many researchers have studied this topic. Gerotor pumps have been widely used in various fields. In this study, we designed a rotor profile based on an envelope of a family of curves. An analytic method for determining the volumetric displacement of the gerotor pump is verified by comparing a result obtained using CAD technology and an experimental result. Throughout the experiment, the flow rate performance was verified. In addition, we describe the design and volumetric displacement characteristics of the gerotor pump.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.5
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• pp.371-379
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• 2009

In this paper, we discussed methods and problems for estimating historical shorelines on a reclaimed land. Since many of coastal lands are unregistered in Korea, reclamation of public waters could cause complicated land ownership dispute. Unlike cadastral boundaries, historical shorelines can be represented by those of various locations due to lack of legal definition of shoreline as well as characteristics of shoreline changes, which directly influence on the calculation of coastal and submerged land areas. Through a case study for Anjeong industrial complex, a systematic method of investigating historical shorelines was suggested to resolve the problems. For a rocky coast where shoreline changes are not likely to occur, a shoreline based on tidal datum was retrieved using aerial photographs taken before the construction of reclamation. Compared with ground survey data, the shoreline was accurate, indicating that the digital photogrammetry was reliable.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.97-104
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• 2015

The performance in scientific contribution of renewable energy R&D has been overlooked, as it is shown in terms of industrial aspect. This paper analyzed the R&D efficiency of scientific aspects of each renewable energy resource in 2008-2012. Total R&D fund and the number of supported projects are selected as input variables, and the number of patents and papers as output variables to analyze the direct efficiency using DEA method. Through the analysis, it determines the efficiency of each energy resource R&D, and investigated the causes of inefficiency. This study has meaning to include entire renewable energy sources for the analysis, and is expected to serve as an important reference in policy making.

• Journal of Korea Port Economic Association
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• v.31 no.3
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• pp.155-166
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• 2015

This study selected container terminals of Gwangyang and Busan Ports to evaluate the influence of efficient container terminals. For the study, after data envelopment analysis (DEA) using the CCR and BCC models, the decision-making unit (DMU) system was used to define nodes; and with the use of a reference group in DEA (BCC model) and a lambda value, this study created a social network and analyzed the influences of efficient DMUs through a centrality analysis of eigenvectors. The results are presented as follows: First, as a result of the DEA, CCR efficiencies in PNC, HJNC, and HPNT container terminals of Busan Port were 1 and BCC efficiencies at Singamman Terminal, Wooam Terminal, PNC, HJNC, HPNT, and BNCT container terminals of Busan Port were 1. Second, as a result of undertaking social network analysis (SNA), according to an eigenvector centrality analysis, HJNC Terminal was referred to the most (influence score of 0.515), which indicates that it is the most influential as a container terminal. The influence of PNC Terminal was 0.512, while that of Wooam Terminal was 0.379. CJ Korea Express in Gwangyang Port was ranked fourth in influence, but its influence score of 0.256 indicates that it was the most influential of the container terminals at Gwangyang Port.

• Journal of the Korean Academic Society of Industrial Cluster
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• v.2 no.1
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• pp.44-60
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• 2008

This paper analyses the relative efficiency and competitiveness of production structure for the industrial clusters(Ulsan, Changwon, Kumi, Wonjoo, Banwol & Siwha, Kwangwju, Gunsan) which had allocated in 2004 in Korea by the DEA approaches. The results show that except U1san, Wonjoo, the 5 industrial clusters have improved the relative efficiency in terms of input and output since they were allocated. And, the reason of the inefficiency for the 5 industrial clusters were not for the technical relationship but for the production scaling size. That is, by clustering for the industrial production firms, the economic effect came true throughout the production scaling size effects. Also, by the positioning approach for the production factors such as labor, capital, and R&D investment via production growth, the results show that Banwol & Siwha, Goomi clusters have effectively been managed, but Wonjoo, U1san and Gunsan are not.

• Journal of Korea Port Economic Association
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• v.30 no.2
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• pp.93-112
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• 2014

To study the business performance, this research reviewed the revenue of 2012 for shipping and logistics companies in Korea, then selected 10 shipping companies and 10 logistics companies according to annual sales amount. These 20 companies are divided into four groups considering their business structure and their financial performance are organized from 2005 to 2012. Then CCR, BCC model has been applied to static efficiency and dynamic changes in productivity for analysis. As an overall result, logistics companies are proven to be better than shipping company in efficiency, change of productivity, growth and profitability. Among the logistics companies, the performance of second party logistics companies are relatively better in those factor above than the third party logistics companies.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.2
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• pp.121-128
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• 2017

This paper was to evaluate social enterprises' management efficiency with Data Envelope Analysis (DEA). The data was based on the 168 social enterprises' of annual performance reports published in 2015. The research focused on to measure both financial efficiency and social impact of the companies simultaneously. To apply DEA, the paper classified the enterprises into seven types based on types of socal impacts which each company provides before the estimation of the efficiency. The research results showed that group D, which employes disadvantaged people, provides social services and shares resources was the most efficient group and had higest net worths in Pure Technical Efficiency. In contrast, Group B, which only employs social advantage people and provides social service, was the least efficient one. The research suggests a practical and efficient framework in measuring social enterprises' management efficiency, including both the financial performance and social impacts simultaneously with their self-publishing reports. Because the Korea Social Enterprise Promotion Agency does not open business reports which social enterprises submit each year, there are basic limitations on researchers attempting to analyse with data from all social enterprises in Korea. Thus, this study dealt with only 10% of the social enterprises which self-published their performance report on the Korea Social Enterprise Promotion Agency's web site. Regardless of these limitations, this study suggested substantial methods to estimate management efficiency with the self-published reports. Because self-publishing is increasing each year, it will be the main source of information for researchers in examining and evaluating social enterprises' financial performance or social contribution. The research suggests a practical and efficient framework in measuring social enterprises' management efficiency, including both the financial performance and social impacts simultaneously with their self-publishing reports. The research results suggest not only list of efficient enterprises but also methods of improvement for less efficient enterprises.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.47-56
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• 2016

This study is on the actual analysis of R&D investment effect through DEA in terms of efficiency resulted from forestry sector climate change response R&D project. Namely, it is clarifying the mechanism of the scientific, technological, social performance result and output, depending on research development cost, employment size as same input. Also, it is in-depth analysis on which performance operates more efficiently in any detailed business. With the study result, we seek political implications to enhance investment effect and core element to consider R&D business project in the future.

• Korean Journal of Agricultural Science
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• v.39 no.2
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• pp.279-289
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• 2012

This study was conducted to survey and diagnose operation status of the agricultural machinery rental service, analyse and compare operational efficiency among 82 city and county ATDEC (agricultural technology development and extension center) using the DEA (Data Envelopment Analysis) method, and recommend future direction, for improvement of the business. Input variables were invested budget and labor, and output variable was rental return. Percentages of return to investment on the rental service were calculated as 68.3% and 63.9% when analyzed with CCR (Charnes, Cooper and Rhodes) and BCC (Banker, Charnes and Cooper) models, respectively, indicating inefficiency of the service operation. Increase of rental charge would increase efficiency by 63.9~68.3% depending on models, and decrease of financial and labor investment would improve the efficiency by about 11.3%. Technical efficiency would be more important than scale efficiency, therefore adjustment of over-invested budget and labor needed to be made together with increase of rental charge to improve the operation. Among the ATDECs providing the rental service, 6 (7.3%), 43 (52.4%), and 33 (40.2%) were in state of CRS (constant return to scale), IRS (increasing return to scale), and DRS (decreasing return to scale), respectively. These indicated public aspects of the rental system, over-investment, lack of output component for input component, meaning that scale income would be increased by qualitative expand of rental charge. Efficiency analysis of the rental system by region showed that efficient ATDECs to be benchmarked by others were in the order of DMU-70, DMU-54, DMU-29, DMU-5, DMU-22, DMU-2, and DMU-61. More comprehensive and extensive survey and analyses would be necessary in the future.