• 무역학회지
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• 제48권1호
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• pp.215-241
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• 2023

항만 간 경쟁이 심화되면서 항만효율성은 더욱 중요하게 인식되고 있다. 항만효율성 개선을 통하여 항만의 지속 가능한 개발을 촉진함과 동시에 지역 및 국가 경제성장을 도모하는 것은 항만운영자뿐만 아니라 지방 및 정부의 주된 관심사이다. 본 연구는 중국의 황금내륙수로인 양쯔강 상의 내륙항만들의 경쟁이 치열해지고 있는 상황에서 2010년부터 2017년까지의 패널자료를 이용하여 장강변 14개 주요 내륙항의 효율성을 분석하고 시간에 따른 항만 효율성의 변화를 살펴보고자 하였다. 동시에 14개 내륙항구를 양쯔강 중류, 상류, 하류 항만군으로 나누어 유역별 항만효율성 수준의 차이를 비교 검토하였다. 특히 본 연구를 수행하기 위해 3단계 DEA 분석 방법을 적용하여 효율성 평가에 영향을 미칠 수 있는 환경적 요인과 통계적 노이즈의 영향을 최대한 배제하여 항만 자체의 순수 상대효율성을 평가하였다. 분석결과, 1단계 효율 평가 결과와 3단계 효율 평가 결과 포트의 효율 값에 뚜렷한 차이가 있음을 확인하였고, 구체적인 결과를 해석과 함께 본문에서 제시하였다. 또한 하류항만들의 효율성이 중·상류 항만에 비해 상대적으로 높은 효율성을 보이고 있음을 알 수 있었다.

• 무역학회지
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• 제41권3호
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• pp.27-42
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• 2016

본 논문에서는 아시아 13개 항만의 2009년, 2010년, 2013년의 자료와, 3개의 투입요소(수심, 총면적 크레인 수)와 1개의 산출요소(컨테이너화물 총 처리량)를 이용하여 교차효율성모형과 메타프론티어 분석방법으로 개별효율성과 그룹효율성, 기술 갭을 측정함으로써, 교차효율성모형에 의해서 측정된 클러스터링이 국내항만들의 메타효율성을 증진시켰는지를 실증적으로 검증하였다. 실증분석의 주요한 결과는 다음과 같다. 첫째, 2010년과 2013년의 경우에는 부산, 인천, 광양항만 모두 그룹효율성이 증가하였다. 둘째, 중국의 항만들이 국내 항만들에 비해서 메타효율성과 그룹효율성 측면에서 더 높은 것으로 나타났다. 셋째, 기술갭 측면에서 보았을 때, 광양항의 기술 격차의 왜곡이 부산항이나 인천항에 비해서 작은 것으로 나타났다. 넷째, 광양항은 2009년(닝보, 칭타오, 토쿄, 카오슝항)과 2013년(두바이항)과 클러스터링을 통해서 효율성을 증진시킬 수 있었다. 부산항은 2010년에 2그룹, 2013년에 1그룹항만, 인천항은 2010년과 2013년에 2그룹 항만들과 클러스터링을 통해서 효율성을 증진시킬 수 있었다. 다섯째, 교차효율성 모형과 메타효율성 분석방법을 통해서 부산, 인천, 광양항은 효율성을 증진시킬 수 있다는 것이 실증적으로 검증되었다. 본 논문의 정책적인 함의는 본 연구에서 실증적으로 검증된 아시아 항만들 간의 클러스터링 방법[부산항은 홍콩, 상하이, 싱가포르항, 인천항과 광양항은 칭타오, 나고야, 닝보, 토쿄, 카오슝항과 클러스터링]을 국내항만들이 적극적으로 정책적인 도입을 해야만 한다.

• 통상정보연구
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• 제16권3호
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• pp.97-119
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• 2014

이 연구에서는 Pulic 등의 부가가치 지적계수(Value Added Intellectual Coefficient, VAICTM) 모형을 이용하여 한국의 은행, 증권사, 보험사 등의 지적자본 효율성을 측정하고, 지적자본을 구성하는 인적, 구조적, 물적 자본과 금융기관의 경영성과 간의 상관관계 및 유의성을 분석하였다. 분석 결과 국내 금융회사중 부가가치 지적계수(VAIC) 및 인적자본 효율성 계수(HCE)는 은행, 보험, 증권 순으로 높았다. 한편, 아시아 주요국 및 세계 10대 은행들과 비교해 볼 때 한국을 포함한 선진국 은행들이 개도국 은행보다 VAIC와 HCE가 높은 것으로 나타났다. 다만, 한국은 호주 등에 비하여 VAIC 및 HCE가 낮은 수준인 것으로 나타났으며 최근 들어 그 수치가 하락세에 있는 것으로 나타났다. 한국 금융서비스 분야의 국제경쟁력 제고를 위하여 노력할 사항을 제기하고 있으며 한국 금융산업이 해외시장 진출을 추진하는데 있어 시사점을 제시하고 있다.

• The Journal of Asian Finance, Economics and Business
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• 제7권6호
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• pp.117-125
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• 2020

This paper aims to investigate FDI attractive factors, which are important to formulate policies to attract Korean direct investment into Vietnam. Based on the literature review and the results of interview with 27 Korean investors in Vietnam, we determined the model of variables attracting Korea's FDI into Vietnam. It is used to assess the impact of attractive factors belonging to three groups of variables to support investment decision; they are macroeconomics variables (including market size factor, labor cost factor, and market openness factor), policies variables (including monetary policy factor and tax rate gap factor), and microeconomics variables (geographic advantage factor representative by location). This research also utilized a relatively new quantitative research method based on the Autoregressive Distributed Lag model (ARDL) with the time data chain from 1995 to 2017 of Korean FDI into Vietnam. It analyzes long-term relationships between dependent variables and independent variables. The result of this study indicates that there are three positive factors (low wages, trade openness and government policy) explaining the FDI flows in the long term. The result also shows that incentive tax policy has had a positive impact on Korean FDI, which has satisfied the aim of seeking efficiency of Korean investors.

• Journal of Korea Trade
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• 제24권7호
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• pp.73-92
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• 2020

Purpose - The letter of credit has been playing a major role to diminish overall risks which exist among concerned parties even though there are differences such as language, culture, law, and distance. This paper reviews essence of the letter of credit and its transaction principles, as well as overall practical questions based on the L/C transaction principle. It also investigates the risk of fraud occurrences in L/C transactions and the importance of fraud prevention and preventive measures in international L/C transactions, including the Fraud Rule, which is a major topic to consider in business transactions. Design/methodology - It is considered that an importing country's concerned parties and an exporting country's concerned parties face different situations. This study employs the existing framework to identify liability, responsibility, and obligation for all concerned parties across countries. Using a quite direct measurement of principles in the letter of credit, such as principle of independence, principle of abstraction, and principle of strictness and coincidence, we studied these differences. Findings - Our main findings can be summarized as follow. The paper enhances the efficiency of the L/C payment method to provide fraud generated from L/C transactions, presentation of a theoretical framework about fraud and fraud prevention, which international trading companies should acknowledge in a material way based on fraud risk resulting from taking advantage of L/C transaction principles. Originality/value - Existing studies focus on fraud accidents in L/C transactions by taking bad advantage of the characteristics of the letter of credit without suggesting risks of fraud. This paper attempts to evaluate and provide preventive measures as a solution for fraud and risky international business in a letter of credit transaction. This area of trade studies is underexplored, both empirically and theoretically, although the issue has long been important to Korean and world community foreign trade.

• 한국항공운항학회지
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• 제22권2호
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• pp.27-33
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• 2014

There are several methods to improve the flight efficiency of HALE(High Altitude Long Endurance) UAV(Unmaned Aerial Vehicle). Airframe structural point of view, weight reduction of the airframe structure is the most important method to improve the flight efficiency. In order to reduce the weight of airframe structures, new concepts which are different from traditional airframe structure design such as the mylar wing skin should be introduced. The spar is the most important component in a mylar skin wing structure, so the spar weight reduction is the key point for reduction of the wing structural weight. In this study, design trade-off study for the front spar of the HALE UAV wing is conducted in order to reduce the weight. Design and analysis procedure of high aspect ratio wing spar are introduced. Several front spar structures are designed and trade-off study regarding the weight and strength for the each spar are performed. Spar design configurations are verified by the static strength test. Finally, optimal front spar design is decided and applied to the HALE UAV wing design.

• Journal of Power Electronics
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• 제11권5호
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• pp.621-631
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• 2011

In space qualified DC-DC converters, optimization of the following electrical characteristics is of greater interest in comparison with other specifications; power loss/efficiency, output voltage ripple and volume/weight. The main goal of this paper is to present an appropriate solution for optimizing the above mentioned characteristics. For this purpose, a comprehensive power loss model of a DC-DC converter is fully developed. Proper models are also demonstrated for assessment of the output voltage ripple and the utilized transformer volume as the bulkiest component in a DC-DC converter. In order to provide a test bed for evaluation of the proposed models, a 50W push-pull DC-DC converter is designed and implemented. Finally, a novel cost function with three assigned weight functions is proposed in order to have a trade-off among the power loss, the output voltage ripple and the utilized transformer volume of the converter. The cost function is optimized for applications in which volume has the highest priority in comparison with power loss and ripple. The optimization results show that the transformer volume can be decreased by up to 51% and this result is verified by experimental results. The developed models and algorithms in this paper can be used for other DC-DC converter topologies with some minor modifications.

• Journal of Korea Trade
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• 제26권1호
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• pp.113-125
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• 2022

Purpose - The primary purpose of this study is to verify whether the target set out by the International Maritime Organization (IMO) for reducing carbon emissions from ships can be achieved by quantitatively analyzing the trends in technological advances of fuel oil consumption in the container shipping market. To achieve this purpose, several scenarios are designed considering various options such as eco-friendly fuels, low-speed operation, and the growth in ship size. Design/methodology - The vessel size and speed used in prior studies are utilized to estimate the fuel oil consumption of container ships and the pace of technological progress and Energy Efficiency Design Index (EEDI) regulations are added. A database of 5,260 container ships, as of 2019, is used for multiple linear regression and quantile regression analyses. Findings - The fuel oil consumption of vessels is predominantly affected by their speed, followed by their size, and the annual technological progress is estimated to be 0.57%. As the quantile increases, the influence of ship size and pace of technological progress increases, while the influence of speed and coefficient of EEDI variables decreases. Originality/value - The conservative estimation of carbon emission drawn by a quantitative analysis of the technological progress concerning the fuel efficiency of container vessels shows that it is not possible to achieve IMO targets. Therefore, innovative efforts beyond the current scope of technological progress are required.

• 한국가시화정보학회지
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• 제20권2호
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• pp.13-20
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• 2022

An effective capacitive deionization process termed membrane capacitive deionization (MCDI) is newly designed and experimentally tested for seawater desalination. By preventing co-ions to be expelled, MCDI can improve the ion removal performance, but there is a trade-off between blocking co-ion transfer and increasing contact resistance. The conventional MCDI uses 2D-shaped films which increase contact resistance and reduce desalination performance in the trade-off. In this paper, with the 3-D shape of Nafion coated activated carbon cloth, the mentioned problems are expected to be solved making the desalination performance better. We visualized ion concentration and fluid flows with half-MCDI cell that can measure only efficiency of cathode. We found the optimal number of coatings which have the better efficiency than CMX, commercial cation exchange membrane in fixed current conditions of 100uA.

• 한국IT서비스학회지
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• 제15권2호
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• pp.51-63
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• 2016

In this study, we conducted a comparative analysis of R&D investment efficiency and operational efficiency of IT firms using Data Envelopment Analysis (DEA). We categorized thirteen sample firms into two groups-IT manufacturing and IT service-after an extensive literature review on IT industry classification. We adopted an output-oriented two-stage DEA model suggested by Banker et al. (1984) with total asset and R&D investment as input variables. Then, we constructed investment efficiency and operational efficiency by using Return on Equity (ROE) and Return on Asset (ROA) as intervening variables and operating income and Earnings Per Share (EPS) as output variables. The outcome of the analysis is summarized as follows. First of all, IT manufacturing firms were more efficient (57% on average) than IT service firms. To be specific, IT service firms showed decreasing returns to scale (DRS) with diseconomy of scale. In contrast, IT service firms showed higher operational efficiency (81.5% on average) than IT manufacturing firms. Also, we conducted a Mann-Whitney U test to compare the output of IT service firms and IT manufacturing firms. Lastly, we found a negative correlation ($R^2$ = -.754) between R&D investment efficiency and operational efficiency which infers the trade-off between two constructs