• Information and Communications Magazine
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• v.4 no.4
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• pp.505-524
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• 1987

Nowaday all the countries of the world have studied the various problems caused in operating their own ports efficiently. Ship delay in the port is attributal to the inefficient operation in the navigation aids, the cargo handling, the storage and transfer facilities, and to the inefficient allocation of gangs or to a bad service for ships. Among these elements the allocation of gangs is the predominating factor in minimizing ship's turn round time. At present, in the case of Pusan Port. the labour union and stevedoring companies allocate gangs in every hatches of ships by a rule of thumb, just placing emphasis on minimizing ship's turn round time, without applying the principle of allocation during the cargo handling. Owing to this the efficiency of the cargo handling could not be expected to be maximized and this unsystematic operation result in supplying human resources of much unnecessary surplus gangs. Therefore in this paper the optimal size and allocation of gangs for minimizing the ship's turn round time is studied and formularized. For the determination of the priority for allocation the evaluation function, namely $F=PHi^{n}{\times}(W+H)$, can be obtained; where, PHI : Principal Hatch Index W : Total Cargo Weight represented in Gang-Shifts H : Total Number of Ship's hatches and also for the optimal size of gangs the average number of gang allocated per shift (Ng), namely Ng=W/PHI, is used. The proposed algorithm is applied to Pusan Port and its validity is verified.

• Journal of Korean Port Research
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• v.1 no.1
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• pp.21-47
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• 1987

Nowaday all the countries of the world have studied the various problems caused in operating their own ports efficiently. Ship delay in the port is attributal to the inefficient operation in the navigation aids, the cargo handling, the storage and transfer facilities, and to the inefficient allocation of gangs or to a bad service for ships. Among these elements the allocation of gangs is the predominating factor in minimizing ship's turn round time. At present, in the case of Pusan Port. the labour union and stevedoring companies allocate gangs in every hatches of ships by a rule of thumb, just placing emphasis on minimizing ship's turn round time, without applying the principle of allocation during the cargo handling. Owing to this the efficiency of the cargo handling could not be expected to be maximized and this unsystematic operation result in supplying human resources of much unnecessary surplus gangs. Therefore in this paper the optimal size and allocation of gangs for minimizing the ship's turn round time is studied and formularized. For the determination of the priority for allocation the evaluation function, namely $F=PHi^{n}{\times}(W+H)$, can be obtained; where, PHI : Principal Hatch Index W : Total Cargo Weight represented in Gang-Shifts H : Total Number of Ship's hatches and also for the optimal size of gangs the average number of gang allocated per shift (Ng), namely Ng=W/PHI, is used. The proposed algorithm is applied to Pusan Port and its validity is verified.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.103-108
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• 2020

Generally, the cargo tank of LPG carriers corresponds to an independent tank Type A defined by the International Maritime Organization (IMO). The outside of the tank is insulated by polyurethane foam, and the tank is made of expensive low temperature steel that can withstand temperatures as low as -50℃. The cargo tank is composed of outer shell plates, bulkheads, stiffeners, web frames, and stringers. Among them, the outer shell plates, bulkheads, and stiffeners can be designed without structural analysis by the Classification Rules and are constructed easily through optimal design. On the other hand, optimal design, including numerous structural analysis, is not performed because web frames and stringers should be designed and approved through structural analysis. Only adequate design, which determines the design dimensions through several dozen structural analysis, is performed. In this study, for finite element analysis, eight loading conditions were applied, and the deformation of the entire ship for each loading condition was considered. The minimum weight design was performed for the web frames of cargo tanks in the 82,000 ㎥ LNG carrier through the gradient-based optimization technique, and the weight was reduced by approximately 108 tons per ship.

• 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 Practical Engineering Education
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• v.16 no.3_spc
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• pp.391-399
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• 2024

All highway toll gates in Korea use low-speed WIM(Weight-In-Motion) to block overloaded cargo vehicles from entering the main highway, but some cargo vehicle owners are illegally modifying vehicles to operate variable axles and evading crackdowns by manipulating the axles. In previous studies detect all tires of a running vehicle were detected to determine whether there is axle manipulation. However, because the vehicle entry area at the highway toll gate checkpoint is very narrow, there is a problem that it is realistically difficult to film all tires of the entering vehicle in one video frame. In this paper, we proposed a system that can determine whether the axle is being operated through changes in the height of the vehicle's cargo box rather than by detecting tires. To detect changes in the height of a cargo box, we propose a method to extract the representative line of the cargo box using Hough transform and then measure the change in height of the representative line to detect the change in height of the cargo box. In addition, we propose a method to detect changes in the vertical height of a cargo box by accumulating motion vectors of pixels within a certain area of the image using optical flow. And the two methods were compared and their advantages and disadvantages were analyzed and presented.

• Journal of the Korean Institute of Navigation
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• v.10 no.1
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• pp.51-79
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• 1986

From time to time the light weight distribution has been discussed, It play an important part in the preliminary design state because of its influence on the available deadweight. Up to the past, the Light weight distribution acting on the ship has been estimated graphically by means of integraph or approximately by the simplified calculations. Recent development has made it possible to use Lloyd's coffin method or Robb's coffin method for Bulk Carrier, Tanker, Cargo ship where the hull weight is distributed based upon the $C_B$ The hull weight distribution is then super-composed by number of fixed weights(i.e. machinery , equipment, etc.) The authors built up the method by which the Light weight distribution is calculated using a computer. In the usual calculations, the higher accuracy is aimed at, the longer time would be taken, therefore the accuracy would not be so good as to be expected if the time is restricted. The method using a computer can dissolve these and calculated accurately in shorter time the Light weight distribution with less data.

• 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 Korea Port Economic Association
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• v.32 no.2
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• pp.39-57
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• 2016

Many countries are developing transportation technologies aimed at reducing environmental pollution and the environmental burden. For example, environmentally friendly transportation routes and methods are being used to improve inland waterways in Europe. Against this backdrop, a case study was conducted on special cargo (weight cargo, earth and sand, etc.) on Korea's Gyeong-In Ara Waterway, an inland waterway connecting the Han River and the West Sea, serving a distribution function. The results of the analysis showed that coastal shipping could be promoted using the waterway, including a positive synergy among environmental, economic, and social aspects. That is, by shifting from overland transportation to marine transportation, it is possible to reduce environmental pollution, ease traffic congestion, decrease traffic accidents, and shorten the licensing period for the weight cargo demand of the northern area of the Han River. In this respect, the Gyeong-in Ara Waterway could become an environmentally friendly transportation route, promoting coastal shipping in Korea. However, for this to occur, support systems such as subsidies for marine transportation and using the inland waterway are required, as happens in the EU. Furthermore, existing policies to promote coastal shipping should be improved and applied more broadly.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.189-194
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• 2010

As the seriousness of the global environment is gaining our attention recently, studies on application of LCA(Life Cycle Assessment) to ship are being carried out dynamically in various industrial fields. This study was carried out to examine the application of LCA to ships and was focused on the inventory analysis on global warming gas from merchant cargo ships. Two merchant cargo ships were adopted as ship models. Actual voyage data of at last several years was used to analysis the ship's exhaust gas inventory. The analysis shows how many weight of global warming gas being exhausted to transport 1 ton of each cargo per 1 nautical mile.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.399-400
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• 2006

LMTT(Linear Motor based Transfer Technology) is a new type of transfer system used in the maritime container terminal fur the port automation, and largely consists of a controller, shuttle car, and rail. The shuttle car is divided into the frame part, the driving part, and wheels. In order to design this system, various researches on each part of it must be conducted. In this study, we dealt with the optimum design for the frame part of the shuttle car designed from previous studies on the strength of the frame with respect to the number of cross beams to minimize the weight of the shuttle car and to satisfy design criteria of cargo-handling systems in container terminal. For the optimization of the frame, thicknesses of each beam were adopted as design variables, the weight of the frame as objective function, and stress and deflection per unit length as constraint condition.