• Journal of the Society of Naval Architects of Korea
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• v.59 no.5
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• pp.314-322
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• 2022

During the shipbuilding process, many blocks are moved between shipyard workshops by block carrying vehicles called a transporter. Because block logistics management is one of the essential factors in enhancing productivity, it is necessary to manage block information with the transporter that moves it. Currently, because a large amount of data per day are collected from sensors attached to blocks and transporters via IoT infrastructure installed in shipyards, automated methods are needed to analyze them. Therefore, in this study, we developed an algorithm that can automatically match the transporter and the working block based on the GPS sensor data. By comparing the distance between the transporter and the blocks calculated from the Haversine formula, the block is found which is moved by the transporter. In this process, since the time of the measured data of moving objects is different, the time standard for calculating the distance must be determined. The developed algorithm was verified using actual data provided by the shipyard, and the correct result was confirmed with the distance based on the moving time of the transporter.

• IE interfaces
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• v.21 no.3
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• pp.274-282
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• 2008

This paper considers a transporter scheduling problem under dynamic block transportation environment in shipbuilding. In dynamic situations, there exist the addition or cancellation of block transportation requirements, sudden breakdowns and maintenance of transporters. The transportation of the blocks in the shipyard has some distinct characteristics. Some blocks are available to be picked up at a specific time during the planning horizon while some other blocks need to be delivered before a specific time. These requirements cause two penalty times : 1) delay times incurred when a block is picked up after a required start time, and 2) tardy times incurred when a block shipment is completed after the required delivery time. The blocks are located at different areas in the shipyard and transported by transporters. The objective of this paper is to propose heuristic algorithms which minimize the weighted sum of empty transporter travel times, delay times, and tardy times. Four heuristic algorithms for transporter scheduling are proposed and their performance is evaluated.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.6
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• pp.646-655
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• 2008

A main issue about production management of shipyards is to efficiently manage the work in process and logistics. However, so far the management of a transporter for moving building blocks has not been efficiently performed. To solve the issues, optimal block transporting scheduling system is developed for minimizing of the travel distance without overload of a transporter. To implement the developed system, a hybrid optimization algorithm for an optimal block transportation scheduling is proposed by combining the genetic algorithm and the ant algorithm. Finally, to evaluate the applicability of the developed system, it is applied to a block transportation scheduling problem of shipyards. The result shows that the developed system can generate the optimal block transportation scheduling of a transporter which minimizes the travel distance without overload of the transporter.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.177-185
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• 2016

In this paper, an optimal planning system for operating transporters in shipyard is developed. The system is designed to utilize the geometries of shipyard, and manage the data of blocks and transporters directly. There are four major menus such as shipyard map management based on GIS, block transportation request, transporter management, and optimal transportation planning in the system. The geometries and properties of the shops, roads, and addresses are manipulated in the shipyard map management menu. The block transportation requests and the properties of transporters are managed in the block transportation request and transporter management menus, respectively. The optimum transportation is planned automatically for minimizing the unload times of the transporters, and the optimum transportation plans are confirmed and printed to the transporter drivers. The effectiveness of the system was verified through the application to a large-sized shipyard.

• IE interfaces
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• v.22 no.1
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• pp.63-72
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• 2009

This paper considers a transporter scheduling problem under dynamic block transportation environment in shipbuilding. In dynamic situations, there exist the addition, cancellation or change of block transportation requirements, sudden breakdowns and maintenance of transporters. The transportation of the blocks in the shipyard has some distinct characteristics. Some blocks are available to be picked up at a specific time during the planning horizon while some other blocks need to be delivered before a specific time. These requirements cause two penalty times: 1) delay times incurred when a block is picked up after a required start time, and 2) tardy times incurred when a block shipment is completed after the required delivery time. The blocks are located at different areas in the shipyard and transported by transporters. The objective of this paper is to propose a heuristic algorithm based on a network flow model which minimize the weighted sum of empty transporter travel times, delay times, and tardy times. Also, a rolling-horizon scheduling method is proposed for dynamic block transportation environment. The performance of the proposed heuristic algorithms are evaluated through a simulation experiment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.spc
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• pp.61-67
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• 2023

Special equipment used for snow removal is only used in the winter and must be moved into storage during non-winter seasons. However, when moving heavy equipment using a forklift within a limited space, safety accidents may occur due to deformation and damage due to the worker's limited visibility and excessive loading of heavy objects. In this study, the scissors boom of the developed heavy load transporter was conducted in two cases: link structural analysis and position-based structural analysis. In detail, the link structural analysis covers four cases of stress and safety factor according to material and thickness to optimize the specifications of the material selected during development, and the structural analysis according to position covers two cases before and after the lift, when maximum stress concentration is achieved. Safety was evaluated through finite element analysis. As a result of the study, when manufacturing a scissors boom type heavy load transporter that can withstand a load of 10 tons, the link showed safety at SS400 4.5mm or higher, and reinforcement is needed in the upper and lower structures, so it is judged to be useful in applying materials according to the load.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.49-56
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• 2023

In this study, we propose a genetic algorithm (GA) to optimize the allocation and operation order of transporters. The solution in the GA is represented by a set of lists each of which the operation order of the corresponding transporter. In addition, it was implemented in the form of a hybrid genetic algorithm combining effective local search operations for performance improvement. The local search reduces the number of operating transporters by moving blocks from a transporter with a low workload into that with a high workload. To evaluate the effectiveness of the proposed algorithm, it was compared with Multi-Start and a pure genetic algorithm through a simulation environment similar in scale to an actual shipyard. For the largest problem, compared to them, the number of transporters was reduced by 40% and 34%, and the total task time was reduced by 27% and 17%, respectively.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.485-486
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• 1999

• Journal of the Society of Naval Architects of Korea
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• v.53 no.2
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• pp.115-126
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• 2016

In the process of ship building, it is known that the maintenance of working period and saving cost are one of the important part during the logistics of blocks transportation. Precise operational planning inside the shipyard plays a big role for a smooth transportation of blocks. But many problems arise in the process of block transportation such as the inevitable road damage during the transportation of the blocks, unpredictable stockyard utilization of the road associated with a particular lot number, addition of unplanned blocks. Therefore, operational plan needs to be re-established frequently in real time for an efficient block management. In order to find the shortest path between lot numbers, there are several representative methods such as Floyd algorithm that has the characteristics of many-to-many mapping, Dijkstra algorithm that has the characteristic of one-to-many mapping, and the A* algorithm which has the one-to-one mapping, but many authors have published without the mutual comparisons of these algorithms. In this study, some appropriate comparison have been reviewed about the advantages and disadvantages of these algorithms in terms of precision and cost analysis of calculating the paths and planning system to operate the transporters. The flexible operating plan is proposed to handle a situation such as damaged path, changing process during block transportation. In addition, an operational algorithm of a vacant transporter is proposed to cover the shortest path in a minimum time considering the situation of transporter rotation for practical use.

• Archives of Obesity and Metabolism
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• v.1 no.2
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• pp.83-88
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• 2022

Obesity increases the risk of developing metabolic diseases such as hypertension, type 2 diabetes, hyperlipidemia, and cardiovascular diseases, as well as some cancers. To prevent the occurrence of these diseases and death, it is essential to manage obesity. Though there are several treatments for obesity, lifestyle interventions, such as diet and exercise, and drug therapy are most widely used in clinical practice. Among the anti-obesity drugs available, the weight loss effect of naltrexone/bupropion has been well-proven. We present a case study in which naltrexone/bupropion, a glucagon-like peptide-1 agonist, and a sodium-glucose transporter 2 inhibitor showed significant weight loss and improved metabolic parameters. Additionally, the management of type 2 diabetes and hypertension, which are common diseases in patients with obesity, was also included.