• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.3
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• pp.409-420
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• 2021

The decrease in under keel clearance (UKC) due to the increase of draft that occurs during advancing and turning of very large vessels of different types was analyzed based on computational fluid dynamics (CFD). The trim change in the Duisburg test case (DTC) container ship was much smaller than that of the KRISO very large crude oil carrier 2 (KVLCC2). The sinkage of both ships increased gradually as the water depth became shallower. The amount of sinkage change in DTC was greater than that in KVLCC2. The maximum heel angle was much larger for DTC than for KVLCC2. Both ships showed outward heel angles up to medium-deep water. However, when the water depth became shallow, an inward heel was generated by the shallow water effect. The inward heel increased rapidly in very shallow water. For DTC, the reduction ratio was very large at very shallow water. DTC appeared to be larger than KVLCC2 in terms of the decreased UKC because of shallow water in advancing and turning. In this study, a new result was derived showing that a ship turning in a steady state due to the influence of shallow water can incline inward, which is the turning direction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.173-174
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• 2010

As the quantity of goods transported, port industry and inland transport industry have developing to transport 630million ton goods annually. And the inland transport industry consists of ground transport for almost 80% of total transported goods. But, ground transport causes some serious problems especially the emission of greenhouse gases from trucks. According to issue "global warming", many regulations and agreements with countries in the world are becoming necessary and it is being fulfilled now. It is sure that Korea will have duty to reduce CO2 emission from 2013. Thus inland transport must cut off CO2 emission level. Therefore this paper will address that the calculation of CO2 emission under route of transportation container from six major container ports in Korea. And then, it will predict CO2 emission of inland transport industry according to increasing container traffic rate at ports.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.369-377
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• 2008

Interest in high productivity and streamlined operation is growing amid a heated competition between ports and mega size vessel oriented operation. It becomes clear that terminals that operate YT(Yard Tractor) for transportation in container yard have less efficiency in operation and cost comparing terminals functioning AGV(Automated Guided Vehicle) system. To offset disadvantages arising out of YT operations, continual efforts (e,g YT pooling operation) were taken place for the last decade, but the result has not been fruitful; YT pooling operation still has a problem in that it cannot read individual YT's actual location. This study suggests 'YT dynamic operation model'- a practical application of RTLS(Real Time Location System) technology which will solve YT pooling operation problems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.119-124
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• 2014

In this paper, A GSm/WCDMA band antenna which can be confirmed positioning information of a container by using the GPS/GLONASS bands on one board and can be sent the positioning information to the mobile communication network in real time is designed. A microstrip patch antennas which supports dual-band (GPS and GLONASS) was optimized. The antenna size is $25{\times}25{\times}5[mm]$. A chip monopole antennas which supports dual-band (GSM and WCDMA) was optimized. The antenna size is $27{\times}8{\times}3.2[mm]$. To amplify the Satellite reception signal level, two-stage low noise amplifier(LNA) was designed. The LNA gain is 27[dB]. The size of Jig for antennas measuring is $100{\times}30{\times}1[mm]$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.1
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• pp.33-49
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• 1997

One of the most important missons that are imposed on merchant ship at sea is to accomplish the safe transportation of cargo loaded. Recently, a study on the seakeeping performance has been carried out on the development of evaluation system related to the synthetic safety of a ship at sea. The seakeeping performance is the ship's ability sailing at, and executing its misson against adverse environmental factors successfully and safely. Until now, however, there has not been any method of quantitative evaluation on the dynamic safety of the ship's cargo loaded. In this regards, this paper has introduced the evaluation method of dynamic safety of the ship's cargo. In order to evaluate the dynamic safety of cargo, the vertical and lateral acceleration which causes the collapse, racking and local structure failure of cargo was adopted as the evaluation factors in the ship's motions. The response amplitude of ship's motions in regular waves is manipulated by NSM (New Strip Method) on a given 2,700 TEU full container vessel under the wind forces of 7, 8 and 9 Beaufort scale. Each response of ship's motions induced by NSM was applied to short-crested irregular waves for stochastic process on evaluation factors and then vertical and lateral acceleration of each cargo was compared with significant amplitude of each acceleration. A representative dangerous factor was determined by comparing permissible values of stacking and racking forces occurred typically to the vertical and transverse directions with the container strength required on ISO 1496 at the positions of forecastle, poop and ship's midship respectively. Through the occurrence probability of the determined factor by Rayleigh's probability density function, the dangerousness which limits loads on container's side wall as an evaluation was applied in judging of the danger of the ship's cargo loaded.

• Journal of the Korean Society for Railway
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• v.19 no.1
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• pp.97-108
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• 2016

Over 80% of Korea's cargo transport relies on public roads. Such over-reliance has created a range of social problems including environmental damage. Korea thus faces an urgent need to establish an alternative mode of cargo transportation. In view of the changing international logistics environment, railway is clearly a superior mode of transport. The prerequisite task today for Korea is to enhance the competitiveness of inland railway by switching to railway and spurring new demand for cargo. This study examines inland railway cargo transport from the demand perspective. Specifically, through the use of a survey, the study identifies key factors influencing the decisions of container shippers regarding the use of railway for cargo transport. The survey responses were statistically tested using Smart PLS structural equation modeling. The results indicate that attitude toward railway use had the strongest influence on choice, while the key variable affecting attitude formation was cost.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.221-228
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• 2010

As container traffic is increasing, the introduction of mega-vessel has had a significant impact on the ports and terminals business. This movement of container shipping has led to intensely competitive environment among ports, so substantial pressures to develop new container ports or to expand existing ones, have been grown. However, it requires a huge investment, especially cost and time, to overcome environmental, geographical and financial restrictions generated from developing a port. This study addressed the Mobile Harbor, the new concept of marine logistics system as an alternative strategy. We performed an economic analysis on the introduction of the Mobile Harbor in coastal transport sector and also a sensitivity analysis to examine the effects of changing factors related on the economic evaluation. We have examined the value and application of Mobile Harbor as a preliminary study, which may contribute to further studies on the Mobile Harbor.

• Journal of Navigation and Port Research
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• v.32 no.6
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• pp.465-471
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• 2008

As the excessive competition between container terminals has been deepening, not only productivity, but also cost economic of the terminals has been raised. With regard to this, the competitiveness of the terminals is limited because of inefficiency operation of transfer crane(T/C) which needs large amount of energy consumption. Therefore, it is possible that the improvement in the T/C operation leads to saving cost for resources and energy as well as increasing the productivity of the terminals. This study provides 'the K-Means Clustering based Optimized Decision Model for Transfer Crane Operation', referring to 'RFID & RTLS based Port Logistics Initiative' of Ministry of Land, Transportation and Maritime Affairs and estimates the efficiency through simulating.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.238-247
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• 2018

This paper considers the problem of scheduling loading and unloading operations of a crane in a railway terminal motivated from rail-road container transshipment operations at Uiwang Inland Container Depot (ICD). Unlike previous studies only considering the total handling time of containers, this paper considers a bi-criteria objective of minimizing the weighted sum of the total handling time and tenant service time. The tenant service time is an important criterion in terms of terminal tenants who are private logistics companies in charge of moving containers from/to the terminal using their trucks. In the rail-road container shipment yard, the tenant service time of a tenant can be defined by a time difference between beginning and finishing loading and unloading operations of a crane. Thus, finding a set of sequences and time of the crane operations becomes a crucial decision issue in the problem. The problem is formulated as a nonlinear program which is improved by linearizing a nonlinear constraint in the model. This paper develops a genetic algorithm to solve the problem and performs a case study on the Uiwang ICD terminal. Computational experiment results show that the genetic algorithm shows better performance than commercial optimization solvers. Operational implications in terms of tenants are drawn through sensitivity analyses.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.7-16
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• 2009

Because the transport policy of Korea has overemphasized road, the physical distribution function of railroad has dwindled a great deal relatively. Recently, the railway has started to be embossed due to the rise of oil prices and environment problems, in addition the government is investing greatly in railroad. The railway corporation took a big step in its history in changing to a public corporation in 2005, and it has been making every possible endeavor to improve management. This research analyzed the trend and stability of the efficiency of railway container handling goods station in korea from 2002 to 2007 based on time of after being changed to a public corporation in 2005 in order to look into the trend of efficiency. The DEA- AR(Data Envelopment Analysis-Assurance Region) and the DEA-Window, widely used as the estimation techniques of the efficiency, were used. According to the results, the efficiency was a little enhanced in 2003 in comparison with 2002, after which it continuously decreased up to 2006 and again rose in 2007. The efficiency of the railway corporation was 0.6777, but after changing to a public corporation, it showed a trend of better efficiency after some transition period had passed.