• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.12
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• pp.2380-2386
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• 2017

Fresh agricultural product in Korea are currently being exported overseas through expensive air transportation, supported by the governments's farm export subsidies. However all members of the World Trade Organization(WTO) must halt government subsidies by 2023. Accordingly, it is necessary to use marine transport capable of carrying freight at low cost. Reefer containers are used for marine transportation of fresh produce but it have a problem due to the temperature difference inside the reefer container which causes of fresh cargo and drop in freshness during sea transportation. In order to solve the problem, we developed a temperature control algorithm for reefer container that maintain a constant temperature and minimizes the deviation inside reefer container. The result showed that the maintained a constant temperature within a maximum of $0.5^{\circ}C$ based on the set-point of $4.0^{\circ}C$ inside reefer container.

• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.25-35
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• 2011

In order to reduce Green House Gas(GHG) reduction in the road freight sector and thus establish green logistics, running efficiency of goods vehicles is of paramount importance. Providing effective transportation infrastructure can contribute to achieve the green logistics by reducing empty running of heavy goods vehicles and van, increasing the average payload on the vehicle, and shifting the transportation mode. In order to reduce the environmental impact from the road freight sector, it is essential to quantify the amount of environmental loading from the sector. However, any systematic survey on the environmental loading from the logistics companies has not been carried out in Korea. In this study, the environmental index for the road freight sector is defined as the amount of $CO_2$ emission per ton km generated from goods vehicles. The computational analysis shows that the average $CO_2$ emission per ton km generated by the logistics companies in Korea is $363g-CO_2/ton{\cdot}km$. Compared to UK (=$130g-CO_2/ton{\cdot}km$) and France (=$97g-CO_2/ton{\cdot}km$), the efficiency of logistics in Korea is 2.8 and 3.7 times as low as in the advanced countries. It also indicates that the main reasons for the low efficiency are mainly due to the high rate of empty operation of goods vehicles and the low payload.

• Journal of Korea Port Economic Association
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• v.35 no.3
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• pp.93-108
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• 2019

This study aims to suggest a containerization plan for non-standardized cargo; it also reveals the significance of containerization in facilitating freight inducement and cargo creation for increasing the competitiveness of the Gwangyang port container terminal and checking excessive competition among terminal operators. Therefore, this study suggested a containerization plan and its significance by dividing 14 items, ones with low containerization ratios or undergoing containerization, bulk, and liquid cargoes. In the case of general cargo, it will be necessary to raise the utilization rate by remodeling a general container or improving cargo loading techniques. In the case of bulk cargo, it will be necessary to exploit the benefits of containerization in preventing product deterioration due to rain, facilitating the sale of small orders, ensuring clean cargo handling, and reducing logistics cost, among others. In the case of liquid cargo, it will be necessary to order and sell liquid cargo in small quantities by using superior quality, safe, and durable Flexitank or Flexibag products, which offer transportation convenience and reduce time and costs.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.1095-1101
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• 2020

Vessels or aircraft should be loaded with containers or cargo to maintain weight balance in order to be stable when navigating the route. The container loading algorithm is known as the NP problem and several heuristic methods have been studied. Containers can be characterized by the uniform volume and weight, which makes it easier to find an optimal loading method. In this paper, we propose an algorithm for weight balance when the volume and weight of an object are uniform. It is assumed that the loading space has a special structure of m * n mesh (where m and n are both odd). In this case, we designed a greedy algorithm and proved that the algorithm is optimal in that it can always find a loading position that maintains a weight balance regardless of the number of objects. Our algorithm can be used in many engineering problems, such as loading algorithms and load balancing problems.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.667-679
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• 2022

Fatigue damage analysis of ships includes parameters considering operational factors. Due to these operational variables, there is a difference between the fatigue damage estimated during the design stage and the actual accumulated fatigue damage. Likewise, there are various loading conditions for the real container ships, but at design stage the fatigue damage is calculated by applying the representative loading conditions. Moreover, although the difference in fatigue damages is expected when the actual and design loading conditions are applied, there are few studies on the contributions of the fatigue damage based on the loading conditions of container ships. In this paper, fatigue contributions were investigated from various cargo weight distributions. The hull girder loads calculated through seakeeping analysis and fatigue damages obtained by performing spectral fatigue analysis were identified under new loading conditions. As a result, it was found that the variation of cargo weight distribution in the container ship brought about changes in the hull girder loads and fatigue damage by affecting the hull girder stress.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.1-9
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• 2018

All ships should ensure stability in accordance with IMO regulations. However, GM is only used to determine ship stability because it takes a lot of time to validate all regulations. This is a problem given that the safety of vessels cannot be guaranteed, potentially leading to accidents. There is a need for a more intuitive and comprehensive method of confirming the stability of ships. This study developed a stability index that expresses ship stability in one value. An index equation is defined based on the 6 stability criteria for ships prescribed by IMO and the result of calculating the ship stability of a model ship. A stability index has been derived for each loading condition by applying the index equation to the same ship. It can clearly be seen that this stability index appropriately explains the criteria. In other words, it is possible to assess ship stability with one value and confirm whether the ship stability satisfies IMO regulations. This index will help masters and officers more easily and accurately check ship stability.

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.375-380
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• 2018

This paper proposes a classification method using the Convolutional Neural Network(CNN) which can obtain the type of trucks from the input image without the feature extraction step. To automatically classify vehicle images according to the type of truck cargo box, the top view images of the vehicle are used as input image and we design the structure of the CNN suitable for the input images. Learning images and correct output results is generated and the weights of neural network are obtained through the learning process. The actual image is input to the CNN and the output of the CNN is calculated. The classification performance is evaluated through comparison CNN output with actual vehicle types. Experimental results show that vehicle images could be classified with more than 90 percent accuracy according to the type of cargo box and this method can be used for pre-classification for inspecting loading defect.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.7-16
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• 2008

There are unique aspects of truck vehicle movements compared with the personal travel in trip chaining. This paper reports an analysis on the truck vehicle trip chaining which intercity/metropolitan/intraregional trips are classified. Data collected from the travel dairy survey is used the truck trip-chaining analysis. The pattern of trip chaining classes is classified by the GIS mapping based on orgin-destination trip information. The physical index and efficiency index for each trip diary is used to the truck vehicle activity. Truck trips lengths and time differs from its truck type, service type and travel patterns. It is shown that the efficiency of the truck trip chaining depends on vehicle types and its delivery patterns. There are many other topics for research on trip chaining modeling such as the classification of trip chain, time use and mode choice by trip chaining.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3426-3433
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• 2015

Three baggage allocation methods of passenger-baggage hybrid train in restricted railway transportation capacity including round conveyor system, vertical circulation system, and horizontal circulation system are presented. Loading/Unloading time is calculated based on the volume transported from Busan to Seoul via Daegu, Daejeon, and Osong with the parcel company P's logistics data. The horizontal circulation system shows less baggage volume capacity to be allocated and the maximum loading/unloading time with 434 secs. The vertical circulation system presents more loading time, but it shows best result with 408 secs. Loading/Unloading times are compared for each system and useful method is presented to improve transportation efficiency of the train.

• Journal of Korea Port Economic Association
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• v.29 no.1
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• pp.47-66
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• 2013

This article reviews some problems arises from signing by the master bills of lading issued on time chartered ship. The underlying purpose of time charters is generally for the charterers to have the services of the vessel in order to engage in the business of carriage of goods by sea, a business which is likely to involve the issue of bills of lading to shippers. Charterer under the charter have a right to issue B/L, thereby the master must sign bill of lading as presented, but may not vary the contract. Bills of lading signed by, or on behalf of the master, impose contractual liabilities upon the shipowner. Charterer have no right to ask the master to sign a bill of lading in any way deviating from the charterparty. If the shipowner suffers loss as a result of the master obeying any order about employment or agency, he will be entitled to an indemnity from the charterer. The master may refuse to sign bills of lading which contain some discrepancy such as a false statement and manifestly inconsistent with the requirements of the charterparty.