• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1533-1540
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• 2001

A high-temperature sodium stainless steel heat pipe was fabricated and its performance has been investigated. The working fluid was sodium and it was sealed inside a straight tube container made of stainless steel. The amount of sodium occupied approximately 20% of the total volume of the heat pipe and its weight was 65.7gram. The length of a stainless steel container is 1002mm and its outside diameter is 25.4mm. Performance tests were carried out in a room air condition under a free convective environment and the measured temperatures are presented. The start-up behavior of the heat pipe from a frozen state was investigated for various heat input values between 600W and 1205W. In steady state, axial temperature distributions of a heat pipe were measured and its heat transfer rates were estimated in the range of vapor temperature from 50$0^{\circ}C$ to 63$0^{\circ}C$. It is found that there are small temperature differences in the vapor core along the axial direction of a sodium heat pipe for the high operating temperatures. But for the range of low operating temperatures there are large temperature drops along the vapor core region of a sodium heat pipe, because a small vapor pressure drop makes a large temperature drop. The transition temperature was reached more rapidly in the cases of high heat input rate for the sodium heat pipe.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.317-323
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• 2006

The objective of this study is to test and modify the gantry travel mechanism of an ALV(automated lifting vehicle) as a main technology of development of ALV. For the purpose of the improvement of container terminal productivity, this study performed to develop the ALV as a part of R&D. In order to verify the design data and detect the errors of detailed drawings, we performed the various limited weight test under load and unload conditions. Through the reflect of final drawing based on the this test, we could use to produce the more complete vehicle.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.45
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• pp.85-109
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• 2010

L/C provides the exporter and the importer with safe assurance in the exchange of goods for payment in international trade. It involves a number of parties. Although the parties may have confidence in their client, bad faith or ignorance of international banking practice by any of these parties could cause the failure of transaction, which makes international trade a risky business. Most of the risks are found in transport document, which can cause disputes. There are many factors in the risk of transport documents under L/C transaction. One most common risk factor for the beneficiary in all transport documents is even if there is no discrepancy in document, the issuing bank or the applicant refuses to pay or delay payment insisting there is a discrepancy. In some very rare cases, the beneficiary may not get paid due to unfair injunction of the local court of the applicant. For the applicant, most common risk factors are fake bill and fraud. Risks classified according to the sorts of transport documents are as follows. 1. In B/L, payment can be refused because it is regarded as charter party B/L, although there is no real charter party contract. And the applicant can bear the potential risk of the loss or deterioration of cargo through transhipment of the cargo loaded on board in container if transhipment is prohibited without excluding of UCP 600 article 20 (c). 2. In charter party B/L, the applicant may take delivery without paying when charter party B/L is signed by charterer, which can result in a big loss for the beneficiary and the negotiating bank. And risks may arise when cargo is seized because the charterer does not pay the hire. The applicant and the issuing bank are also vulnerable to a risk - Against whom should they file a suit when cargo gets damaged during transportation? 3. In multimodal transport document, which is subject to a conflict because there is a big difference in viewpoints between transport industry and banks, conflicts may also arise when L/C requires ocean B/L and accepts multimodal transport document at the same time, but does not specify the details. 4. In air waybill, where the consignee is not the issuing bank but the applicant, risks may take place to the beneficiary when the applicant takes delivery but refuses to pay asserting minor discrepancies in document. The applicant may also bear the risk when cargo may not be loaded because air waybill is a received bill. Another risk may arise when although the applicant prohibits transhipment without excluding UCP 600 article 23 (c), the cargo may be transhipped, provided that the entire carriage is covered by one and the same air waybill.

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.149-154
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• 2017

Recently, container terminal operators have made efforts to develop an efficient remarshalling plan in response to the increase in automation of equipment handling and transport of containers in the terminals. Usually, containers are handled by multiple AYCs(automated yard cranes) in-yard in an automated container terminal, and terminal operators establish a remarshalling plan using slack time to increase the efficiency of ship operation. This study develops the optimal mathematical model through mixed integer programming as a solution to the problem of dispatching multiple AYCs. Considering the difficulty of direct application to the field due to computation time, we analyze the five prototypical dispatching rules for real world adaptation. A numerical experiment found that the maximum weight ratio (MR) rule and the maximum weight (MW) rule are the ideal dispatching solutions to the multiple AYCs dispatching problem.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.97-104
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• 2009

Ever increasing fuel prices, almost doubled in the last three years, and global pressure to reduce their environmental impact have been enforcing commercial vessel operators and designers to re-assess current vessel designs with emphasis on their propulsion systems and operational practices. In this paper the "Inclined Keel Hull (IKH)" concept, which facilitates to use larger propeller diameter in combination with lower shaft speed rates and hence better transport efficiency, is explored for a modern 3600 TEU container vessel with the aim of fitting an 13 % larger diameter propeller (and hence resulting 20% lower rpm) to gain further power saving over the similar size basis container ship with conventional "level keel" configuration. It appears that successful application of the "inclined keel Hull" concept is a fine balance amongst the maximum gain in propulsive efficiency, minimum increase in hull resistance and satisfaction of other naval architectural and operational requirements. In order to make the concept economically more viable, this paper concentrates on the fore body design with the possible combination of increase of volume in its fore body to recover the expected volume loss in the aft body due to the space for larger propeller and its low wave-making resistance to minimize the efficiency loss using a well-established optimization software.

• Journal of Navigation and Port Research
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• v.34 no.5
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• pp.311-317
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• 2010

Mobile Harbor(MH) is a new paradigm for maritime transport system introduced in Korea, the target of which is to carry out ship-to-ship cargo operation rapidly and effectively even under a condition of sea state 3. A MH ship is moored alongside a large container vessel anchored at the defined anchorage and also equipped with gantry cranes for handling containers. The MH study concerned includes rapid container handling system, optimum design for floating structure, hybrid berthing & cargo operation system, design for cargo handling crane, etc. This paper is to deal with a conceptual design of a stabilized mooring system and mooring equipment under a condition of ship-to-ship mooring. In this connection, we suggest a positioning control winch system in order to control heave motions of the MH ship which is to add constant brakepower and stabilized function to an auto-tension winch and mooring equipment used currently in large container ships.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.237-246
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• 2015

In this paper, Improved productivity models of container terminal are provided by utilizing a simulation considering Tandem-lift Quay Crane and transport vehicle of container's high productivity 'Alternative ship-to-yard vehicles.' Feature of this method is deriving the data of tandem-lift Quay Crane and Alternative ship-to-yard vehicles, estimating the productivity model of tandem-lift Quay Crane by using regression analysis. Tandem-lift Quay Crane is equipment of loading and unloading to increase productivity approximately by 2 time existing (single, twin) Quay Crane by dealing with four 20ft containers or two 40ft containers at the same. Alternative ship-to-yard vehicles can transfer containers(4TEU) more than existing Yard Tractor. This paper is deriving the optimal combination showing the highest productivity by using simulation considering Tandem-lift Quay Crane and Alternative ship-to-yard vehicles on container terminals and developing estimating model of productivity by using regression analysis using data of simulation.

• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.611-622
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• 2021

Composite material-due to low density-causes weight savings, which results in lower fuel consumption of transport vehicles. The aim of the research was to change the existing base-plate of the aluminum airplane container with the composite sandwich plate in order to reduce the weight of the containers of cargo aircrafts. The newly constructed sandwich plate consists of aluminum honeycomb core and composite face-sheets. The face-sheets consist of glass or carbon or hybrid fiber layers. The orientations of the fibers in the face-sheets were 0°, 90° and ±45°. Multi-objective optimization method was elaborated for the newly constructed sandwich plates. Based on the design aim, the importance of the objective functions (weight and cost of sandwich plates) was the same (50%). During the optimization nine design constraints were considered: stiffness, deflection, facing stress, core shear stress, skin stress, plate buckling, shear crimping, skin wrinkling, intracell buckling. The design variables were core thickness and number of layers of the face-sheets. During the optimization both the Weighted Normalized Method of the Excel Solver and the Genetic Algorithm Solver of Matlab software were applied. The mechanical properties of composite face-sheets were calculated by Laminator software according to the Classical Lamination Plate Theory and Tsai-Hill failure criteria. The main added-value of the study is that the multi-objective optimization method was elaborated for the newly constructed sandwich structures. It was confirmed that the optimal new composite sandwich construction-due to weight savings and lower fuel consumption of cargo aircrafts - is more advantageous than conventional all-aluminum container.

• Journal of Navigation and Port Research
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• v.46 no.1
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• pp.33-41
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• 2022

An important operational goal of a container terminal is to maximize the efficiency of the operation of quay cranes (QCs) that load and/or unload containers onto and from vessels. While the maximization of the efficiency of the QC operation requires minimizing the delay of yard tractors (YT) that transport containers between the storage yard and QCs, the delay is often inevitable because of traffic congestion. In this paper, we propose a method for learning a model that predicts traffic speed in a terminal using only YT operation data, even though the YT traffic is mixed with that of external trucks. Without any information on external truck traffic, we could still make a reasonable traffic forecast because the YT operation data contains information on the YT routes in the near future. The results of simulation experiments showed that the model learned by the proposed method could predict traffic speed with significant accuracy.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.16 no.1
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• pp.110-116
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• 2020

As the management plan for domestic spent nuclear fuel is delayed, the storage of the operating nuclear power plant is approaching saturation, and the Kori 1 Unit that has reached its end of operation life is preparing for the dismantling plan. The first stage of dismantling is the transfer of spent nuclear fuel stored in storage at plants. The spent fuel management process leads to temporary storage, interim storage, reprocessing and permanent disposal. In this paper, the technical issues to be considered when transporting spent fuel in this process are summarized. The spent fuels are treated as high-level radioactive waste and strictly managed according to international regulations. A series of integrity tests are performed to demonstrate that spent fuel can be safely stored for decades in a dry environment before being transferred to an intermediate storage facility. The safety of spent fuel transport container must be demonstrated under normal transport conditions and virtual accident conditions. IAEA international standards are commonly applied to the design of transport containers, licensing regulations and transport regulations worldwide. In addition, each country operates a physical protection system to reduce and respond to the threat of radioactive terrorism.