• 유통과학연구
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• 제11권8호
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• pp.5-14
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• 2013

Purpose - We live in a world of constant change and competition. Many airports have specific competitiveness goals and strategies for achieving and maintaining them. The global economic recession, financial crises, and rising oil prices have resulted in an increasingly important role for facility investment and renewal and the implementation of appropriate policies in ensuring the competitive advantage for airports. It is thus important to analyze the factors that enhance efficiency and productivity for an airport. This study aims to determine the efficiency levels of 20 major airports in East Asia, Europe, and North America. Further, this study also suggests suitable policies and strategies for their development. Research design, data, and methodology - This paper employs the DEA-CCR, DEA-BCC, and DEA-Malmquist production index analysis models to determine airport efficiency. The study uses data on the efficiency and productivity of the world's leading airports between 2006 and 2010. The input variables include the airport size, the number of runways, the size of passenger terminals, and the size of cargo terminals. The output variables include the annual number of passengers and the annual cargo volume. The study uses basic data from the 2010 World Airport Traffic Report (ACI). The world's top 20 airports (as rated by the ACI report) are investigated. The study uses the expanded DEA Model and the Super Efficiency Model to identify the most effective airports among the top 20. The Malmquist productivity index analysis is used to measure airport effectiveness. Results - This study analyzes longitudinal and cross-sectional data on the world's top 20 airports covering 2006 to 2010. A CCR analysis shows that the most efficient airports in 2010 were Gatwick Airport (LGW), Zurich Airport (ZRH), Vienna Airport (VIE), Leonardo da Vinci Fiumicino Airport (FCO), Los Angeles International Airport (LAX), Seattle-Tacoma Airport (SEA), San Francisco Airport (SFO), HongKong Airport (HKG), Beijing Capital International Airport (PEK), and Shanghai Pudong Airport (PVG). We find that changes in airport productivity are affected more by technical factors than by airport efficiency. Conclusions - Based on the study results, we offer four airport development proposals. First, a benchmark airport needs to be identified. Second, inefficiency must be reduced and high-cost factors need to be managed. Third, airport operations should be enhanced through technical innovation. Finally, scientific demand forecasting and facility preparation must become the focus of attention. This paper has some limitations. Because the Malmquist productivity index is based on the hypothesis of the, the identified production change could be over- or under-estimated. Further, as DEA estimates the relative efficiency. It also cannot generalize to include all airport conditions because the variables are limited. To measure airport productivity more accurately, other input variables and environmental variables such as financial and policy factors should be included.

• 디지털융복합연구
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• 제15권10호
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• pp.31-43
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• 2017

본 연구는 DEA의 CCR/BCC 모형과 Malmquist 생산성 지수를 이용하여 택배 서브터미널 위수탁 대리점의 운영효율성을 분석했다. 투입변수로는 종업원수, 장비수, 영업비용을 선정하였으며 산출변수는 매출액을 선정하여 2014년부터 2016년 기간의 효율성을 분석하였다. 연구결과 CCR 모형과 BCC모형 모두 2014년 대비 2016년 효율성이 좋아졌으며 벤치마킹 분석결과 2016년 기준 DMU1과 DMU7이 가장 효율성이 좋은 것으로 나타났다. 또한 BCC 모형 기준 비효율성 분석결과 2014년 기준 2016년 모든 요소별 효율성이 증가한 것으로 나타났다. Malmquist 분석결과 MPI지수는 기술변화에 영향을 받아 소폭 하락하였으며 모든 DMU에서 기술퇴보가 이루어지고 있는 것으로 나타났다. 본 연구는 택배에 대한 인식을 제고하고 그동안 논문에서 다루지 않았던 서브터미널 위수탁 대리점의 실제 운영효율성을 분석하였으며 그 결과 위수탁 대리점에 대한 정부의 제도개선 및 지원정책이 필요함을 시사점으로 제시하였다. 본 연구는 파주, 김포의 신도시 택배대리점을 기준으로 분석을 수행하였다. 따라서 향후 분석범위를 타도시 및 구도심으로 넓혀 신도시와의 비교를 통한 효율성분석을 수행해야 한다.

• 한국항만경제학회지
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• 제37권2호
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• pp.91-105
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• 2021

컨테이너선의 대형화 추이에 따라 일정 지역 내에 있는 항만 간에 컨테이너 화물을 유치하기 위한 경쟁이 치열해지고 있다. 결국, 컨테이너선의 기항 여부는 항만의 효율성과 직결되며, 항만의 효율성 분석은 항만 운영업자와 관리자의 의사결정에 영향을 미치는 강력한 경영 도구가 되며 항만 운영 계획을 수립하는데 유용한 정보를 제공한다. 본 연구는 지중해 지역에 있는 주요 컨테이너 항만들의 기술적 효율성을 조사하고 특정 요소가 컨테이너항만의 효율성에 어떤 영향을 미치는지 분석하는 데 목적이 있다. 비용 효율성은 CCR 모형과 BCC 모형을 사용하여 측정되었으며 주요 분석 대상은 지중해에 있는 7개국 12개 항만을 대상으로 하였다. 주요 항만은 발렌시아, 제노아, 암발리, 포트사이드, 알렉산드리아 등을 포함하고 있다. 본 연구는 지중해 지역에 있는 주요 항만의 효율성을 분석한 연구로써 의미가 있다. 또한, 연구 결과를 통해 어떤 변수에 주안점을 두어야 할지에 대한 기초 자료와 사전적 연구로서 의미가 있으며 또한 주요 해운항만 정책 입안자 또는 항만 운영업자 등의 효율적 의사결정에 유의미한 정보를 제공한다.

• 해양환경안전학회지
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• 제29권1호
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• pp.60-66
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• 2023

현재의 해양산업의 기술은 스마트 선박 및 자율운항선박 등의 개발과 같은 자율화 및 지능화와 환경규제의 강화에 맞추어 선박의 운항 효율성을 개선하는 친환경 선박을 위한 기술이 함께 개발되고 있다. 이러한 흐름에 맞추어, 세계각국에서는 선박의 안전운항을 보장하는 선에서 선박운항효율을 극대화하기 위해 다양한 방식으로 노력하고 있다. 본 연구에서는, 현존하는 선박운항효율 개선 기술이 운항 당시의 기상환경, 선박조종 등의 선박운항상태를 실시간으로 반영하지 못하는 문제를 개선하기 위해, 선박에서 수집한 선박운항데이터를 활용하여 실시간 선박운항효율 분석모델을 개발하고자 한다. 본 연구의 실시간 선박운항효율 분석모델은 연료소모를 기준으로 판단한 선박운항효율과 당시의 선박운항상태를 감안하여 판단한 선박운항효율을 비교하여, 식별된 선박운항효율의 타당성을 확인할 수 있는 모델이다. 분석의 주요 내용은 대상선박의 선정과 선박운항데이터의 수집, 선박운항효율 특성과 선박운항상태 특성의 구분, 그리고 이를 활용한 분류모델의 개발을 포함한다. 연구의 결과는 기존의 선박운항효율과 항해 당시 선박운항상태를 감안한 운항효율을 제시하여 선박 운항자의 의사결정을 지원하여 운항효율을 개선하고자 한다.

• Journal of electromagnetic engineering and science
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• 제18권1호
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• pp.13-19
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• 2018

Wireless power transfer (WPT) based on magnetic resonant coupling is a promising technology in many industrial applications. Efficiency of the WPT system usually depends on the tilt angle of the transmitter or the receiver coil. This work analyzes the effect of the tilt angle on the efficiency of the WPT system with horizontal misalignment. The mutual inductance between two coils located at arbitrary positions with tilt angles is calculated using a numerical analysis based on the Neumann formula. The efficiency of the WPT system with a tilted coil is extracted using an equivalent circuit model with extracted mutual inductance. By analyzing the results, we propose an optimal tilt angle to maximize the efficiency of the WPT system. The best angle to maximize the efficiency depends on the radii of the two coils and their relative position. The calculated efficiencies versus the tilt angle for various WPT cases, which change the radius of RX ($r_2=0.075m$, 0.1 m, 0.15 m) and the horizontal distance (y=0 m, 0.05 m, 0.1 m), are compared with the experimental results. The analytically extracted efficiencies and the extracted optimal tilt angles agree well with those of the experimental results.

• 산업공학
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• 제24권4호
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• pp.330-340
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• 2011

This research aims at conducting a comparative study on the relative efficiency of technologically innovative activities between manufacturing and service industries using data envelopment analysis (DEA). First, as an individual approach, efficiency of technologically innovative activities between manufacturing and service industries is separately evaluated. The results show that efficiency of both industries is similarly low, but patterns of technologically innovative activities differ from each other. Manufacturing industries usually do innovation focusing on various outputs with a single input, whereas service industries tend to do innovation emphasizing on a single output with mixed inputs. Second, as a holistic approach to both industries, efficiency is collectively assessed. The analysis demonstrates that efficiency of service industries is higher than that of manufacturing industries, and there are similar patterns of technologically innovative activities between both manufacturing and service industries. This study provides industrial managers with policy implications based on similarities and differences between manufacturing and service industries.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.359-362
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• 2009

Optimal efficiency control of synchronous reluctance motor(SynRM) is very important in the sense of energy saving and conservation of natural environment because the efficiency of the SynRM is generally lower than that of other types of AC motors. This paper is proposed a novel efficiency optimization control of SynRM considering iron loss using multi adaptive fuzzy learning controller(AFLC). The optimal current ratio between torque current and exciting current is analytically derived to drive SynRM at maximum efficiency. This paper is proposed an efficiency optimization control for the SynRM which minimizes the copper and iron losses. There exists a variety of combinations of d and q-axis current which provide a specific motor torque. The objective of the efficiency optimization control is to seek a combination of d and q-axis current components, which provides minimum losses at a certain operating point in steady state. The control performance of the proposed controller is evaluated by analysis for various operating conditions. Analysis results are presented to show the validity of the proposed algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.776_777
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• 2009

Optimal efficiency control of synchronous reluctance motor(SynRM) is very important in the sense of energy saving and conservation of natural environment because the efficiency of the SynRM is generally lower than that of other types of AC motors. This paper is proposed a novel efficiency optimization control of SynRM considering iron loss using neural network(NN). The optimal current ratio between torque current and exciting current is analytically derived to drive SynRM at maximum efficiency. This paper is proposed an efficiency optimization control for the SynRM which minimizes the copper and iron losses. The design of the speed controller based on adaptive learning mechanism fuzzy-neural networks(ALM-FNN) controller that is implemented using fuzzy control and neural networks. The objective of the efficiency optimization control is to seek a combination of d and q-axis current components, which provides minimum losses at a certain operating point in steady state. The control performance of the proposed controller is evaluated by analysis for various operating conditions. Analysis results are presented to show the validity of the proposed algorithm.

• 한국항행학회논문지
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• 제20권5호
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• pp.408-416
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• 2016

본 연구에서는 선내 수집데이터를 활용하는 선박 및 육상 서비스를 위한 선박용 어플리케이션 시스템과 해상 데이터 통합관리 및 상호교환을 위한 선육 간 통합 시스템을 활용한 선박 에너지효율 모니터링 시스템을 설계하였다. 선박 에너지효율 모니터링 시스템은 윈도우 기반의 응용프로그램으로 file base EDI 통신을 이용하도록 구성하였다. 주요기능으로 연료소모량 최소화를 위한 항로 계획, 에너지 소모 및 배출가스 배출 모니터링, 선박 에너지 효율 분석 및 분석데이터 분석을 구현하고 실 운항선박에 적용하여 시스템의 정상 동작을 확인하였다.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.17-27
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• 2020

With the continuous development and application of Internet technology, in recent years, new technologies such as cloud computing, big data, the Internet of Things, and AI are becoming more and more familiar to the general public. The development of a digital society has entered a new period of development. In this paper, we used on the 2018 annual data of 50 listed companies with blockchain concept stocks in China. Using data envelopment analysis (DEA) to study and analyze the input-output efficiency, it can be concluded that the input-output efficiency of 50 listed companies is very different. Inefficient companies are as high as 62%. Most companies have a large room for improvement in input-output efficiency due to uneconomical scale or inefficient technology. In order to better improve the company's input-output efficiency, one must improve the efficiency of resource utilization, optimize the company's research and development costs and the input and management of technical personnel; the second is to increase technological innovation and business innovation.