| 1. |
- Jeong, Yong-Kuk, 1989-, et al.
(författare)
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A Spatial Layout Optimization Program considering the Survivability of a Naval Vessel in the Early Design Stage
- 2019
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Ingår i: Journal of Ship Production and Design. - : Society of Naval Architects and Marine Engineers. - 2158-2866 .- 2158-2874. ; 35:2, s. 126-138
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Tidskriftsartikel (refereegranskat)abstract
- As mission capability and scope of naval vessels are increasing, there has been an emphasis on the importance of survivability of naval vessels. Elements of survivability include susceptibility, vulnerability, and recoverability among which vulnerability is directly associated with the interior spatial layout of a naval vessel. However, various other elements also must be simultaneously considered in the design phase of a naval vessel. Accordingly, this study proposes a method that considers survivability an assessment factor by quantifying vulnerability in attacks, which is directly associated with the effect of spatial layout of a naval vessel. Furthermore, to automatically create spatial layout alternatives of naval vessels and efficiently deduce optimum spatial layout results, this study developed an optimization program for the spatial layout of naval vessels. The differential evolution algorithm was used for the optimization, and its effectiveness was validated by applying it to various examples.
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| 2. |
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| 3. |
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| 4. |
- Jeong, Yong-Kuk, 1989-, et al.
(författare)
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Shipyard Block Logistics Simulation Using Process-centric Discrete Event Simulation Method
- 2018
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Ingår i: Journal of Ship Production and Design. - : The Society of Naval Architects and Marine Engineers. - 2158-2866 .- 2158-2874. ; 34:2, s. 168-179
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, shipyards have conducted various studies to accurately investigate their production capacities and improve the accuracy of their production plans. Nevertheless, frequent delays in schedules inevitably occur at production sites. Simulation-based techniques are used in various fields to solve similar problems, especially those related to predicting loads on facilities and upgrading production planning by considering various constraints. Process-centric simulation modeling techniques are used in shipyards because the shipbuilding process has different characteristics from the general manufacturing process. Conventional resource-oriented modeling techniques are inadequate to construct a simulation model to analyze the logistical behavior of shipyards. In this study, a process-oriented simulation modeling method is applied and improved through the identification and development of additional modules needed to simulate the behavior of shipyard logistics. The core of the simulation is improved using a logistic token that can analyze the physical movement effected by each process. Moreover, such process modeling modules as the geographic information system, the route search module, and the spatial arrangement module are developed and integrated into one solution.
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| 5. |
- Lee, Dong Kun, et al.
(författare)
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Optimized design of electric propulsion system for small crafts using the differential evolution algorithm
- 2014
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Ingår i: International Journal of Precision Engineering and Manufacturing-Green Technology. - : Korean Society for Precision Engineering. - 2288-6206 .- 2198-0810. ; 1:3, s. 229-240
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Tidskriftsartikel (refereegranskat)abstract
- Given the stricter environmental regulations and rising oil prices, means of transportation based on eco-friendly fuel are drawing increased attention. Electric propulsion systems (EPSs) have been applied to various means of transportation, including cars, and many studies have examined ships equipped with EPSs. Generally, because of the low energy density of the battery, EPS-equipped vehicles experience the disadvantages of limited operating time and distance compared to fossil fuel-based vehicles. In this study, we developed an algorithm that determines the optimal electric motor and battery specifications for the basic requirements of a small craft equipped with an EPS. Moreover, to control the stability of the craft, we developed an algorithm that optimally arranges EPS components, wherein the center of gravity is used as an object function. The differential evolution algorithm was used for optimization, and the effectiveness was verified by applying this algorithm to the actual design of a small craft. The proposed algorithm represents the research results for determining the basic EPS specifications for a small craft and deriving an optimal arrangement for these specifications. This algorithm is expected to be effectively applied to design a new electric propulsion ship or to convert an existing ship to an electric propulsion ship.
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| 6. |
- Lee, Jong Moo, et al.
(författare)
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Development of an evaluation framework of production planning for the shipbuilding industry
- 2018
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Ingår i: International Journal of Computer Integrated Manufacturing. - : Taylor & Francis. - 0951-192X. ; 31:9, s. 831-847
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Tidskriftsartikel (refereegranskat)abstract
- Shipbuilding competitiveness can be improved by implementing a production planning system that reflects production environments and can achieve a high degree of completion. Unfortunately, even South Korean shipbuilders, which are the world's most competitive, lack relevant research on the objectives, and a comprehensive evaluation method for the systemisation of the production planning process and the results of production planning. This study proposes a comprehensive ship production planning process by analysing production planning tasks executed in major South Korean shipyards. In addition, it proposes an evaluation framework and an evaluation system to assess production planning based on an integrated production planning process. The evaluation framework consists of the planning stage and the stage of operation in a company, thereby enabling evaluation of production planning from multiple perspectives. In addition, while establishing the evaluation system for the results of production planning in large-scale shipyards, the study presents the core items necessary to introduce and build a real evaluation system through the framework.
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| 7. |
- Shen, Huiqiang, et al.
(författare)
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Analysis on Hull Block Erection Process Considering Variability
- 2021
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Ingår i: Journal of Ship Production and Design. - : The Society of Naval Architects and Marine Engineers. - 2158-2866 .- 2158-2874. ; 37:02, s. 67-77
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Tidskriftsartikel (refereegranskat)abstract
- Research Institute of Marine Systems Engineering, Seoul National University, Seoul, South Korea The hull block erection network process, which is performed during the master production planning stage of the shipyard, is frequently delayed because of limited resources, workspace, and block preparation ratio. In this study, a study to predict the delay with respect to the block erection schedule is conducted by considering the variability of the block preparation ratio based on the discrete event simulation algorithm. It is confirmed that the variation of the key event observance ratio is confirmed according to the variability caused by the block erection process, which has the minimum lead time in a limited resource environment, and the block preparation ratio. Furthermore, the optimal pitch value for the key event concordance is calculated based on simulation results.
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| 8. |
- Shin, Jong Gye, et al.
(författare)
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Model-Based Computational Shipyard Dynamics and Its Applications
- 2020
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Ingår i: Journal of Ship Production and Design. - : The Society of Naval Architects and Marine Engineers (SNAME). - 2158-2866 .- 2158-2874. ; 36:1, s. 87-95
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Tidskriftsartikel (refereegranskat)abstract
- A ship production system can be represented by various production factors and production management indicators. To manage such a system efficiently, a theory is required to analyze and predict its behavior. The theory should be able to fully express the relationships between production factors and production management indicators. For this purpose, computational shipyard dynamics was proposed by Kim et al. in the Journal of Ship Production and Design (2018). This methodology includes input variables, output variables, and key performance indicator (KPI) functionals, implemented as a simulation model. In this study, a rigorous approach to realize a model of a complex ship production system is presented by embodying previous research. A model-based ship production system theory is defined, which consists of production factors, production management indicators, and the relationships between them, called the simulation-based KPI functionals. The production factors are defined using a six-factor model, and the production management indicators are defined using KPIs that are already used in shipyards so that they are quantitatively measurable. To verify the proposed theory, it was applied to fabrication shop, panel block assembly line, and ship block logistics simulation cases, which are examples that are similar to the job shop, flow shop, and project shop cases, respectively.
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