| 1. |
- Lindholm, Carl-Johan, et al.
(författare)
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Experimental analysis of stresses in curved sandwich structures
- 2015
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Ingår i: 20th International Conference on Composite Materials.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Some studies indicate that the cross-section of large wind turbine blades subjected to wind and gravity loads will ovalise due to the Brazier effects [1,2]. This feature could however not be verified by numerical experiments of a FE model of a fictive 61.5 m blade, based on the NREL 5MW reference turbine [3], subjected to simplified load cases. Accurate prediction of failure modes of sandwich structures based on finite element calculations are highly important if accurate predictions of such features in large wind turbine blades are to be investigated.In this study, an experimental setup designed to cause deflection and stress patterns in the core similar to what might be achieved by the Brazier effect in a wind turbine blade subjected to severe wind loads has been carried out. The test set up will highlight stress in the through-thickness direction, causing classical shell theory to be circumspect as a modelling tool. By designing specimens with different foam core material properties, stiffness and strength, different failure modes were observed in the test. Through the use of combinations of solid and shell elements and geometrically nonlinear analyses, the experimental effects were shown to be predictable by an otherwise linear FE model.
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| 2. |
- Lindholm, Carl-Johan, et al.
(författare)
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Experimental analysis of stresses in sandwich structures due to the brazier effect
- 2015
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Ingår i: ICCM International Conferences on Composite Materials. ; 2015-July
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Konferensbidrag (refereegranskat)abstract
- © 2015 International Committee on Composite Materials. All rights reserved. Some studies indicate that the cross-section of large wind turbine blades subjected to wind and gravity loads will ovalise due to the Brazier effects [1,2]. This feature could however not be verified by numerical experiments of a FE model of a fictive 61.5 m blade, based on the NREL 5MW reference turbine [3], subjected to simplified load cases. Accurate prediction of failure modes of sandwich structures based on finite element calculations are highly important if accurate predictions of such features in large wind turbine blades are to be investigated. In this study, an experimental setup designed to cause deflection and stress patterns in the core similar to what might be achieved by the Brazier effect in a wind turbine blade subjected to severe wind loads has been carried out. The test set up will highlight stress in the through-thickness direction, causing classical shell theory to be circumspect as a modelling tool. By designing specimens with different foam core material properties, stiffness and strength, different failure modes were observed in the test. Through the use of combinations of solid and shell elements and geometrically nonlinear analyses, the experimental effects were shown to be predictable by an otherwise linear FE model.
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| 3. |
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| 4. |
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| 5. |
- Febring, Linda, et al.
(författare)
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Pedagogisk design
- 2020
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Fernquist, Johan, et al.
(författare)
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Online Hate A Study on the Feasibility to Detect Hate Speech in Swedish
- 2019
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Ingår i: 2019 Ieee International Conference On Big Data (Big Data). - : IEEE. - 9781728108582 ; , s. 4724-4729
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Konferensbidrag (refereegranskat)abstract
- Elate speech in digital environments is becoming a societal challenge. To deal with the problem, techniques that automatically detect hate speech have been developed by social media companies as well as researchers. Hate can be expressed in many different ways, which makes it difficult to detect. automatically using algorithms. Also, how hate is expressed depends heavily on the language. The effectiveness of automatic detection techniques is still to be improved in many languages. In this paper, we attempt to detect hate speech in Swedish using machine learning. We compare different pre-trained language models that are line-tuned on a corpus of hateful comments. To examine how well our models would work in a real scenario, we used a set of randomly selected comments from a Swedish discussion forum. The results showed that using pre-trained language models provides a better result than using a baseline SVM model, but it also reveals that detecting hate speech in the wild is challenge that need more research.
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| 7. |
- Johansson, Anders, 1982, et al.
(författare)
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Modeling and Calibration of Small-scale Wind Turbine Blade
- 2014
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Ingår i: Topics in Experimental Dynamic Substructuring, Volume 2, Proceedings of the 31st IMAC, A Conference on Structural Dynamics, 2013. - New York, NY : Springer New York. - 2191-5644. ; 36:2, s. 51-58
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Konferensbidrag (refereegranskat)abstract
- The SEM Substructuring Focus Group has chosen an Ampair 600W wind turbine to be used as a test bed in the continued efforts to further experimental and experimental-analytical substructure coupling techniques. To assess such coupling techniques, validated models of the parts, the substructures considered, play a crucial role. This paper describes the modeling, calibration and validation of a Finite Element (FE) model of a blade for the test bed turbine. State-of-the-art composite material modeling is used to set up the model, which is calibrated and validated based on results from an ambitious measurement campaign including both nondestructive testing for dynamic properties and dedicated destructive tests for deduction of material properties. The measurement campaign is carefully described in the paper.
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| 8. |
- Lindholm, Joel, et al.
(författare)
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DrAST: an inspection tool for attributed syntax trees (tool demo)
- 2016
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Ingår i: SLE 2016 Proceedings of the 2016 ACM SIGPLAN International Conference on Software Language Engineering. - New York, NY, USA : ACM. - 9781450344470 - 9781450344470 ; , s. 176-180
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Konferensbidrag (refereegranskat)abstract
- When implementing a language by means of attribute grammars, it is often useful to study example programs and their attributed trees, to understand the compiler structure, or for debugging. DrAST is a tool that allows interactive inspection of attributed trees. It is interfaced to the JastAdd metacompiler, and supports all JastAdd attribution mechanisms, such as demand evaluation, reference attributes (graph edges), and nonterminal attributes. A challenge in visualizing attributed trees is that they are large, even for small programs. To allow the user to focus on the aspects of interest, DrAST supports the interactive definition of filtered versions of the tree through a domain-specific language which allows conditional filtering based on the attributes themselves. We have used DrAST on a variety of language implementations, from tiny compilers used in teaching to a complete Java compiler.
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| 9. |
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| 10. |
- Olsen, Henrik Palmer, et al.
(författare)
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Re-framing case law citation prediction from a paragraph perspective
- 2023
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Ingår i: Legal knowledge and information systems. - : IOS Press. - 9781643684727 - 9781643684734 ; , s. 323-328
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Konferensbidrag (refereegranskat)abstract
- Case law citation prediction, i.e., predicting what historical cases are relevant for your current case, can assist legal discovery and decision-making, but legal documents are long, and often only parts of them are relevant for a particular use case. We therefore reframe case law citation prediction as a paragraph-to-paragraph citation task, introduce a new dataset, and train and evaluate new models. We also evaluate our models qualitatively. Our resources provide a first step toward discovering citation patterns and modeling legal rules in EU law from precedent documents.
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