| 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. |
- Kim, Youngmin, et al.
(författare)
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Computational Shipyard Dynamics
- 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. ; 34:4, s. 355-367
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Tidskriftsartikel (refereegranskat)abstract
- Early simulations focused mainly on virtualizing the shipyard itself and the approach in terms of production management that focuses on improving productivity was hardly sufficient. For systematically approaching shipyard production problems, to which the dynamics between various factors are applied, this study uses the shipyard simulation information model to explain the six factors, which are the input variables of the shipyard production system simulation. Then, the objective or output variable is set up as the key performance index (KPI) by aligning the interests from an enterprise perspective. The output variable, KPI, is generally expressed as a function of functions of the input variables, namely a functional. To evaluate the value of the functional, a computational method in the form of a simulation is used. The process-centric simulation is adopted as it is appropriate for the shipyard production system simulation, which is an engineered-to-order industry, and it is easy to implement the concept of dynamic resolution. According to this methodology, we present a simulation application that focuses on the fabrication shop of a shipyard.
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| 3. |
- 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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| 4. |
- 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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| 5. |
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| 6. |
- Flores-García, Erik, et al.
(författare)
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Characterizing Digital Dashboards for Smart Production Logistics
- 2022
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Ingår i: Advances in Production Management Systems. Smart Manufacturing and Logistics Systems: Turning Ideas into Action. - Cham : Springer Nature Switzerland AG. - 9783031164101 - 9783031164118 ; , s. 521-528, s. 521-528
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Konferensbidrag (refereegranskat)abstract
- Developing digital dashboards (DD) that support staff in monitoring, identifying anomalies, and facilitating corrective actions are decisive for achieving the benefits of Smart Production Logistics (SPL). However, existing literature about SPL has not sufficiently investigated the characteristics of DD allowing staff to enhance operational performance. This conceptual study identifies the characteristics of DD in SPL for enhancing operational performance of material handling. The study presents preliminary findings from an ongoing laboratory development, and identifies six characteristics of DD. These include monitoring, analysis, prediction, identification, recommendation, and control. The study discusses the implications of these characteristics when applied to energy consumption, makespan, on-time delivery, and status for material handling. The study proposes the prototype of a DD in a laboratory environment involving Autonomous Mobile Robots.
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| 7. |
- Jeong, Yongkuk, et al.
(författare)
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Digital Twin-Based Services and Data Visualization of Material Handling Equipment in Smart Production Logistics Environment
- 2022
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Ingår i: Advances in Production Management Systems. Smart Manufacturing and Logistics Systems. - Cham : Springer Nature. ; , s. 556-564
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Konferensbidrag (refereegranskat)abstract
- Smart production logistics has introduced in manufacturing industries with emerging technologies such as digital twin, industrial internet of things, and cyber-physical system. This technological innovation initiates the new way of working, working environment, and decision-making process. Especially the decision-making process has changed from experience and intuition to knowledge and data driven. In this paper, digital twin-based services, and data visualization of material handling equipment in smart production logistics environment are presented. There are several applications of digital twin in manufacturing industries already, however feedback from the virtual environment to physical environment and interactions between them which are the essential features of digital twin are very weak in many applications. Therefore, we have developed digital twin-based services in the laboratory scale including feedback and interaction. In addition, data visualization application of material handling equipment in automotive industry is presented to provide insights to the users. Both applications have developed based on the same framework including database and middleware, so it has possibilities to develop further in the future.
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| 8. |
- 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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| 9. |
- Kanoni, Stavroula, et al.
(författare)
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Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis.
- 2022
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Ingår i: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906 .- 1474-7596. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N=1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.
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| 10. |
- 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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