| 1. |
- Cheung, Hon Lam, et al.
(författare)
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A multi-fidelity data-driven model for highly accurate and computationally efficient modeling of short fiber composites
- 2024
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Ingår i: Composites Science and Technology. - 0266-3538. ; 246
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Tidskriftsartikel (refereegranskat)abstract
- To develop physics-based models and establish a structure–property relationship for short fiber composites, there are a wide range of micro-structural properties to be considered. To achieve a high accuracy, high-fidelity full-field simulations are required. These simulations are computationally very expensive, and any single analysis could potentially take days to finish. A solution for this issue is to develop surrogate models using artificial neural networks. However, generating a high-fidelity data set requires a huge amount of time. To solve this problem, we used transfer learning technique, a limited amount of high-fidelity full-field simulations, together with a previously developed recurrent neural network model trained on low-fidelity mean-field data. The new RNN model has a very high accuracy (in comparison with full-field simulations) and is remarkably efficient. This model can be used not only for highly efficient modeling purposes, but also for designing new short fiber composites.
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| 2. |
- Finnsgård, Christian, 1974, et al.
(författare)
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Swedish shippers’ strategies for coping with slow-steaming in deep sea container shipping
- 2018
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Ingår i: Journal of Shipping and Trade. - : Springer Singapore. - 2364-4575. ; 3:8
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Tidskriftsartikel (refereegranskat)abstract
- When container shipping lines experience over-capacity and high fuel costs, they typically respond by decreasing sailing speeds and, consequently, increasing transport time. Most of the literature on this phenomenon, often referred to as slow-steaming, takes the perspective of the shipping lines addressing technical, operational and financial effects, or a society perspective focusing on lower emissions and energy use. Few studies investigate the effects on the demand side of the market for container liner shipping. Hence, the aim of this study is to elaborate on the logistics consequences of slow-steaming, particularly the strategies that Swedish shippers purchasing deep sea container transport services employ to mitigate the effects of slow-steaming. Workshops and semi-structured interviews revealed that shippers felt they had little or no impact on sailing schedules and were more or less subject to container shipping lines’ decisions. The effects of slow-steaming were obviously most severe for firms with complex supply chains, where intermediate products are sent back and forth between production stages on different continents. The shippers developed a set of strategies to cope with the low punctuality of containerised shipping, and these were categorised in the domains of transfer-the-problem, transport, sourcing and distribution, logistics and manufacturing, and product design. All firms applied changes in the transport domain, although the lack of service segmentation limited the effects of the strategy. Most measures were applied by two firms, whereas only one firm changed the product design.
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| 3. |
- Sundin, Maria, 1965, et al.
(författare)
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Space Sports - Sailing in Space
- 2016
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Ingår i: Proceedings from icSports 2016, 4th International Conference on Sport Sciences Research and Technology Support, Porto, Portugal, 7-9 november 2016. - : SCITEPRESS - Science and Technology Publications. - 9789897582059 ; , s. 141-146
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Konferensbidrag (refereegranskat)abstract
- Titan is the largest moon of Saturn, and apart from the Earth it is the only body in our solar system where a liquid exists on the surface. Within the last ten years a system of lakes and rivers have been discovered. The climate and seasonal cycles of Titan are still not very well known, but the composition and pressure are fairly well established. Perhaps in the future boats will sail the lakes of Titan for research purposes or even sport. The purpose of this paper is to give an overview of the concept of space sports, the conditions of Titan and to calculate important parameters of sailing such as floatability, stability, hull resistance and sail forces. This paper shows that if a sailing yacht on Titan will have twice as large displacement as on Earth, it will be 2.6 times less stable for the same beam. Since friction will be smaller, it will be faster than on Earth at low speed, but significantly slower at high speeds due to the wave generation. The same sail area is required to get the same sail forces if the average wind is 3 m/s, while a 9 times larger sail area is required for if the wind speed is only 1 m/s.
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| 4. |
- Finnsgård, Christian, 1974, et al.
(författare)
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Costs, not SECAs make RoRo steam slow
- 2017
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Ingår i: HANSA International Maritime Journal. - : HANSA. - 0017-7504. ; 154:1, s. 42-43
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The issue of speed is more complex for RoRo/RoPax vessels than other segments. A Swedish research team has addressed the preconditions for introducing slow steaming in Northern Europe and asked operators in Scandinavian waters how they prepared and have acted under SECA
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| 5. |
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| 6. |
- Finnsgård, Christian, 1974, et al.
(författare)
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Slow steaming from the shippers’ perspective
- 2015
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Ingår i: 2015 METRANS International Urban Freight Conference (I-NUF), October 21-23 2015. Long Beach, California..
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Konferensbidrag (refereegranskat)abstract
- Trans-ocean liner shipping companies adopt slow steaming during periods when the market is characterized by low demand, high fuel prices, low freight rates and over capacity. The latest instance this has occurred is in the period following the 2008/2009 global financial crises and the speeds have not yet rebound to the pre-crisis levels. Most of the existing research regarding slow steaming is from environmental, economical and maritime engineering perspective, meaning that the phenomenon is studied from the ship owners’ perspective. The purpose of this paper is to explore the effects of slow steaming from the shippers’ perspective. A structural literature review on the main subject has been performed and the same resulted in a matrix of different effects of slow steaming on the shippers already identified and studied in the existing literature. Furthermore, six global companies positioned in Sweden have been studied and the data from the case companies has been collected through face-to-face interviews. The findings of the interviews have been summarized, presented and discussed at a workshop with all case companies’ representatives. The results of the study show that the shippers were firstly affected by slow steaming in 2008 and 2009 simply through increased sailing times that affected their supply chains. Reliability has been regarded as more important than the sailing time itself but the improvement on the same has not been observed so far. Furthermore, the interviewees believe that if the sea transport option is unreliable, air and rail are considered as substitute supply chains and the same also affects the last mile mode choice. Remarkably only one shipper acknowledged the importance and existence of environmental benefits; however increased reliability or cost reduction, as the benefits, have not been recognized by the interviewees.
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| 7. |
- Finnsgård, Christian, 1974, et al.
(författare)
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Slow steaming från varuägarnas perspektiv
- 2015
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Ingår i: Transporteffektivitetsdagen 2015. 27 Augusti 2015, Örebro..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Finnsgård, Christian, 1974, et al.
(författare)
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Slow Steaming Logistics – A study of shippers’ ability to demand, and manage the consequences of, slow steaming maritime transportation services in their supply chains
- 2015
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Ingår i: 16th Nordic Maritime Universities Workshop. 22-23 januari 2015. Chalmers, Göteborg..
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Konferensbidrag (refereegranskat)abstract
- About 90 per cent of the total volumes of goods that are imported to, or exported from, Sweden have been carried using maritime transport at some part of the transport chain. Swedish industry and commerce are hence heavily dependent on access to effective and efficient maritime transport services. At the same time the IMO estimates that roughly 3 per cent of the global CO2 emissions stem from maritime transport. In addition, the shipping industry is the source of about 15% of the global SOX and NOX emissions. The challenge at hand is hence, to reduce the negative external effects of shipping while at the same time accommodating an increasing demand, without adversely affecting the shippers’ ability to fulfill their needs for maritime transport. One of the most potent measures for reducing fuel consumption and consequently, emission, is reduction of sailing speed; so called slow steaming. Due to the non-linear correlation between speed and fuel consumption (e.g. the admiralty formula which estimates a cube function; meaning a 10% speed reduction yields 27% fuel consumption reduction), even marginal speed reduction will result in substantial reduction in fuel consumption. Historically, any time slow steaming has been broadly employed in the shipping industry; it has been so unilaterally by the ship owners. The rise in the application of slow steaming by linear shipping companies, is attributed to the flaccid demand, abundance of capacity, high fuel prices and low freight rates. Based on the existing knowledge, it is reasonable to anticipate that, despite the negative abatement costs and potency of slow steaming as a measure for reduction of emissions, its use will likely decline as soon as the market conditions rebound. The purpose of this study is to explore and explain the shippers’ ability to demand, and manage the consequences of, slow steaming maritime transport services in their supply chains. The Slow Steaming Logistics study has explored how the shippers are effected by interviewing six global companies originating in Sweden. The represent both import and export, the manufacturing industry as well as consumer goods and fashion – a wide selection of case companies. The case companies have been interviewed, and gathered for a workshop on the topic. The results from the study indicated that the shippers were firstly affected by slow steaming in 2008 or 2009, and the main indicator has been increased sailing times, that in turn affect their supply chains. The interviews also indicate that reliability can is regarded as more important than the sailing time itself. However, the shippers would like a diversity in the offering in the market for trans-ocean container freight, else other options as airfreight and railroad is considered for supply chains that today utilize trans-ocean containers shipping lines.
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| 9. |
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| 10. |
- Sundin, Maria, 1965, et al.
(författare)
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Vi ska segla i metan på Titan
- 2016
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Ingår i: Forskning & Framsteg. - : Forskning & Framsteg. - 0015-7937. ; 2016:7, s. 42-47:7, s. 42-47-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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