• International Journal of Automotive Technology
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• v.8 no.6
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• pp.697-704
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• 2007

Recently, a variable valve timing system has been widely adopted in internal combustion engine in order to improve the fuel economy and torque at low engine speed. In addition, it is known that varying valve timing according to the various engine operations could reduce exhaust gas, especially NOx, because of residual gas by valve overlap. In this study, to improve the low exhaust gas and fuel economy at part load condition, the residual gas and back flow of exhaust gas due to valve overlap were calculated computationally. Moreover, the characteristics of engine performances and NOx formations were investigated with the experiment of combination of intake and exhaust valve timing condition. Under these various valve operating conditions, the effects of both the positive valve overlap and negative valve overlap(valve underlap) were examined simultaneously. Finally, the characteristics of cyclic THC emission were analyzed by using Fast Response FID(FR-FID) in the cylinder, intake port and exhaust port positions. Besides, the effect of the different gradients of the valve timing change on engine performance was investigated and an optimum control strategy was suggested.

• Journal of Korea Port Economic Association
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• v.37 no.2
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• pp.91-105
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• 2021

The current increasing size of container vessels affects the container port's situation. The containerization has changed the inter-modal handling process, which brought more flexibility and comfortableness in the shipping industry sector. Thus, it is very crucial to analyze the efficiency of container ports in the regional sphere. Such kind of efficiency analysis provide a powerful management tool for port operators and shipping managers in the Mediterranean market, and it also helps to form an information for planning new regional and national port operations. This paper aims to analyze the ports' technical efficiency of Mediterranean major container ports. It is conducted to establish the model of port performance and efficiency through the empirical test of the various factors. Regarding to the panel data collected from the 48 DMUs (decision making units), this study attempts to provide the empirical basis of the port efficiency relative to another factors in the total port performance. Due to the complexity of the various activities carried out at container ports, the study focuses only on the technical efficiency at the level of the Mediterranean container port. Unlike the practice of cross-sectional data analysis, originally established by Charnes et al. (1985), the panel data in DEA window analysis applications are used. The main focus of this study is the relative technical efficiency of 12 container ports from 7 countries in the Mediterranean market. The selection of ports under study is based on their high handling capability and rankings in World Top 100 (Containerization International, 2018).

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.273-280
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• 2003

The purpose of this study is to identify and evaluate the competitiveness of ports in ASEAN(Association of Southeast Asian Nations), which plays a leading role in basing the hub of international logistics strategies as a countermeasure in changes of international logistics environments. This region represents most severe competition among Mega hub ports in the world in terms of container cargo throughput at the onset of the 21 st century. The research method in this study accounted for overlapping between attributes, and introduced the HFP method that can perform mathematical operations. The scope of this study was strictly confined to the ports of ASEAN. which cover the top 100 of 350 container ports that were presented in Containerization International Yearbook 2002 with reference to container throughput. The results of this study show Singapore in the number one position. Even compared with major ports in Korea (after getting comparative ratings and applying the same data and evaluation structure), the number one position still goes to Singapore and then Busan(2) and Manila(2), followed by Port Klang(4), Tanjugn Priok(5), Tanjung Perak(6), Bangkok(7), Inchon(8), Laem Chabang(9) and Penang(9). In terms of the main contributions of this study, it is the first empirical study to apply the combined attributes of detailed and representative attributes into the advanced HFP model which was enhanced by the KJ method to evaluate the port competitiveness in ASEAN. Up-to-now, none have comprehensively conducted researches with sophisticated port methodology that has discussed a variety of changes in port development and terminal transfers of major shipping lines. Moreover, through the comparative evaluation between major ports in Korea and ASEAN, the presentation of comparative competitiveness for Korea ports is a great achievement in this study. In order to reinforce this study, it needs further compensative research, including cost factors which could not be applied to modeling the subject ports by lack of consistently qualified in ASEAN.

• Journal of Navigation and Port Research
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• v.34 no.10
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• pp.817-821
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• 2010

As the environment of Logistics is changing rapidly, the environment of port is also changing. Accordingly, rapid change within port environment appears as the increase of the volume for world wide cargo, liner ship owners' strategy shift, globalization of terminals, heavy competitions to become a hub of Logistics, development of ship engineering. Therefore, the people who are responsible for the operations and managements of ports foresee such changes and accordingly react to ensure competitiveness. As the competition among ports generally goes international, a port needs to be sure that they become superior to any other port regardless of whether it's outside their country or not. Especially Korea is located in the most heavily competitive area which is Far-East. So if we fail to get competitiveness against the other ports, it goes without saying that our ports will be defeated by them. In brief, this paper will discuss the history of study regarding the factors by which a port is selected and also suggest some of elements which can be applied to small ports in the future of it.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.167-170
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• 2013

The objective of this paper is to describe the result of development of collision avoidance supporting system, based on the electronic chart display and information system(ECDIS). In real ship operations, collision accidents happen frequently due to human errors such as the lax vigilance, misinterpretation of international regulations for preventing collisions at sea (COLREGs). We developed a system which will help to avoid these kind of accidents. This system can automatically recognize the risk of collisions, generate the safe alternative routes that comply with COLREGs, and then deliver the results into auto pilot. A virtual simulation assuming progressive collision situations revealed the usefulness of this system.

• Journal of Korea Port Economic Association
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• v.37 no.4
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• pp.51-70
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• 2021

This study measured the environmental efficiency of 21 international airports based on sustainability reports issued by each airport for 2018. As many sectors in the industry paid attention to social and environmental responsibilities, airport operators comprise one of the leading sectors that streamlined their facilities to become increasingly sustainable and environmental. Nevertheless, studies on the environmental operations of airports are insufficient compared with studies on economic or operational efficiency. Therefore, the current study aims to determine any possible improvement in the environmental inefficiency of airports with the utilization of directional distance function (DDF) and to examine operational efficiency with the application of the data envelopment analysis (DEA). The majority of airports have operated their facilities efficiently, but not all have effectively managed pollutants generated by airports. Furthermore, many airports can still potentially reduce CO₂ and water consumption. This study suggests several implementable environmental improvements to the aviation sector. Moreover, other industrial sectors may use the research as a benchmark for enhancing environmental efficiency.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.524-533
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• 2020

The free-trade-zone system has been implemented in industrial-complex-type free-trade zones with a focus on the manufacturing industry since 1970, and was intended to attract foreign investment and increase trade by providing benefits such as tax reduction and deregulation to tenant companies. However, foreign investment in these industrial-complex-type free trade zones has decreased significantly. On the other hand, port-type free-trade zones have great potential to attract foreign investment for development due to the increase in port traffic. The developmental trends in the free-trade-zone system have been studied primarily in the manufacturing industry, and those studies must be extended. In this paper, the role and operation of free-trade zones are examined and problems highlighted. We analyzed a business model specialized in port-type free-trade zones to identify problems, propose measures to improve the system for re-exporting domestic goods to the customs area for storage, and upgrade overall operations. The effects of our measures were analyzed by simple simulation. These proposed improvements in the operation of port-type free-trade zones will help attract foreign companies to these international logistics hubs and global delivery centers.

• Journal of Navigation and Port Research
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• v.44 no.4
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• pp.347-353
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• 2020

Aids to Navigation (AtoN) contribute to preventing marine accidents and protecting marine environment by providing various information such as location information etc. to ships. Recognizing the importance of the AtoN, a 24 won of the AtoN service fee is charged for ships entering and leaving international trade ports. However, while the 24 won of the AtoN service fee has been maintained since its establishment in 1999, the demand for new roles of the AtoN service for autonomous shipping and smart port operations, etc. has gradually increasing with the change of shipping and port 4.0. Thus the purpose of this study was to estimate the appropriate level of the AtoN service fee in accordance with such changes in the shipping and port industries. To accomplish this, a method of recovering the total cost was introduced to the PROOF (Pyeongtaek Regional Office of Ocean and Fisheries). It is estimated that there are four cases in which estimation of the AtoN service fee is estimated in two cases year by year and conversion year, the AtoNs of PROOF are classified into the all and part of a ship using the trade port. As a result of the estimation, the AtoN service fee of PROOF is estimated at 53.78-71.62 won (as of 2019), and 29.78-47.62 won is higher than the today at 24 won. The results of this study can be used as useful basic data for the operation of budgets and policy management considering the role of the AtoN.

• Journal of Korea Port Economic Association
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• v.31 no.2
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• pp.69-83
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• 2015

This study proposes effective overseas market entry strategies that could allow Korean logistics companies to develop international capabilities and become global firms by adapting to environmental changes in global logistics. First, it reviews the overseas networks of Korean international freight forwarders and the recent trends in the global logistics market. Then, it surveys the conditions of two groups of freight forwarders, namely partnerships and subsidiaries, which are categorized according to type of entry into foreign markets. These companies' networks are concentrated in East and Southeast Asia regardless of network type. As a result, the ability for partnerships to network is higher than that of subsidiaries. However, subsidiaries are small in number and located in various regions because of their initial stage, which is why their businesses depend on the price competitiveness of the parent company. The satisfaction and performance of subsidiaries are both generally low according to the presented findings. In addition, the successful strategies of international freight forwarders include following operations, specializing their logistics services, building collaborations among small and medium-sized companies, recruiting and training professional human resources in international logistics, and entering markets together with their customers. Overall, this study highlights the importance of measuring and evaluating objectively the level and performance of overseas networking through a survey about the internationalization of Korean freight forwarder companies. To conclude, this study is considered to contribute to raising their global competitiveness by suggesting strategies derived from the survey findings and SWOT analysis.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.193-202
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• 2006

The Consultative Meeting of the Convention on the Prevention of Marine Pollution by Dumping of Wastes and other matter, 1972 (London Convention 1972) has requested to International Maritime Organization (IMO) Marine Environmental Protection Committee to collaborate and help clarify a boundary issue between International Convention for the Prevention of Pollution from Shops, 1973 as modified by the Protocol of 1978 (MARPOL) and the London Convention concerning 'dumping' versus 'discharges' during normal operations of ships in 2004, and subsequently established a Joint London Convention/MEPC Correspondence Group. The Contracting Parties to London Convention expressed their environmental concerns on the broad interpretation of the "cargo-associated wastes" by the States, which could be discharged by ships under MARPOL. Regulatory regimes for the cargo residues appear to vary among states. Some countries require fur ships to discharge their cargo wastes into the port reception facility and IMO also recommends doing so. This paper examines the related current national and international legal texts for the regulation of disposal of wastes from ships in order to analyze the current global concern on the marine pollution associated with waste discharge during operations of ships. In particular, we attempt to evaluate the likely marine environmental consequences arising from the disposal of cargo residue using an hypothetical case for the coal cargo residue among bulk cargos in this paper, since location, magnitude and frequency of the discharge of coal cargo residues into the sea adjacent to Korean Peninsula are not readily available. The cargo residues may be discharged to the sea according to MARPOL 73/78; however, its marine environmental consequences can be significant depending upon the characteristics and amounts of wastes to be discharged. Also the public tolerance of the environmental consequences would be widely different among nations. Multilateral environmental agreements, in general, more strictly apply their rules if there are other options to disposal at sea, i.e. port reception facility in this case. Therefore, port reception facilities for the wastes generated by ships are recommended to be further constructed in major national ports in order to reduce the risk of environmental damages during the operations of ships.