| 1. |
- Flodén, Liselott, 1967-, et al.
(författare)
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A myriad shades of green
- 2009
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Ingår i: Proceedings of Bridges 2009, Banff, Alberta, Canada.
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Konferensbidrag (refereegranskat)abstract
- We discuss the possible application of techniques inspired by the theories of G-convergence and homogenization to understand mixtures of colors and how they appear as observed by the human eye. The ideas are illustrated by pictures describing the equivalent of a convergence process for different kinds of mixtures of colors.
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| 2. |
- Flodén, Liselott, 1967-, et al.
(författare)
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On the determination of effective properties of certain structures with non-periodic temporal oscillations
- 2009
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Ingår i: MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling. - Wien : Vienna University Press (WUV). - 978-3-901608-35-3 ; s. 2627-2630
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Konferensbidrag (refereegranskat)abstract
- We investigate the homogenization of an evolution problem modelled by a parabolic equation, where the coefficient describing the structure is periodic in space but may vary in time in a non-periodic way. This is performed applying a generalization of two-scale convergence called λ-scale convergence. We give a result on the characterization of the λ-scale limit of gradients under certain boundedness assumptions. This is then applied to perform the homogenization procedure. It turns out that, under a certain condition on the rate of change of the temporal variations, the effective property of the given structure can be determined the same way as in periodic cases.
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| 3. |
- Flodén, Liselott, et al.
(författare)
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Very weak multiscale convergence
- 2010
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Ingår i: Applied Mathematics Letters. - 0893-9659. ; 23:10, s. 1170-1173
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Tidskriftsartikel (refereegranskat)abstract
- We briefly recall the concept of multiscale convergence, which is a generalization of two-scale convergence. Then we investigate a related concept, called very weak multiscale convergence, and prove a compactness result with respect to this type of convergence. Finally we illustrate how this result can be used to study homogenization problems with several scales of oscillations.
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| 4. |
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| 5. |
- Holmbom, Anders, 1958-, et al.
(författare)
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Detection of scales of heterogeneity and parabolic homogenization applying very weak multiscale convergence
- 2011
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Ingår i: Annals of Functional Analysis. - Mashdad, Iran : TSMG. - 2008-8752. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- We apply a new version of multiscale convergence named very weak multiscale convergence to find possible frequencies of oscillation in an unknown coefficient of a diffeential equation from its solution. We also use thís notion to study homogenization of a certain linear parabolic problem with multiple spatial and temporal scales
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| 6. |
- Tourancheau, Sylvain, 1982-, et al.
(författare)
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Evaluation of quality of experience in interactive 3D visualization: methodology and results
- 2012
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - SPIE - International Society for Optical Engineering. - 9780819489357 ; s. Art. no. 82880O
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Konferensbidrag (refereegranskat)abstract
- Human factors are of high importance in 3D visualization, but subjective evaluation of 3D displays is not easy because of a high variability among users. This study aimed to evaluate and compare two different 3D visualization systems (a market stereoscopic display, and a state-of-the-art multi-view display) in terms of task performance and quality of experience (QoE), in the context of interactive visualization. An adapted methodology has been designed in order to focus on 3D differences and to reduce the influence of all other factors. 36 subjects took part in an experiment during which they were asked to solve different tasks in a synthetic 3D scene. After the experiment, they were asked to judge the quality of their experience, according to specific features. Results showed that scene understanding and precision was significantly better on the multi-view display. Concerning the quality of experience, visual comfort was judged significantly better on the multi-view display and visual fatigue was reported by 52% of the subjects on the stereoscopic display. This study has permitted to identify some factors influencing QoE such as prior experience and stereopsis threshold.
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| 7. |
- Tourancheau, Sylvain, 1982-, et al.
(författare)
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Subjective evaluation of user experience in interactive 3D-visualization in a medical context
- 2012
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Ingår i: Proceedings of the SPIE, vol 8318: Conference on Image Perception, Observer Performance, and Technology Assessment, San Diego, CA, USA, 4 - 9 February 2012. - SPIE - International Society for Optical Engineering. ; s. Art. no. 831814
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Konferensbidrag (refereegranskat)abstract
- New display technologies enable the usage of 3D-visualization in a medical context. Even though user performance seems to be enhanced with respect to 2D thanks to the addition of recreated depth cues, human factors, and more particularly visual comfort and visual fatigue can still be a bridle to the widespread use of these systems. This study aimed at evaluating and comparing two different 3D visualization systems (a market stereoscopic display, and a state-of-the-art multi-view display) in terms of quality of experience (QoE), in the context of interactive medical visualization. An adapted methodology was designed in order to subjectively evaluate the experience of users. 14 medical doctors and 15 medical students took part in the experiment. After solving different tasks using the 3D reconstruction of a phantom object, they were asked to judge their quality of the experience, according to specific features. They were also asked to give their opinion about the influence of 3D-systems on their work conditions. Results suggest that medical doctors are opened to 3D-visualization techniques and are confident concerning their beneficial influence on their work. However, visual comfort and visual fatigue are still an issue of 3D-displays. Results obtained with the multi-view display suggest that the use of continuous horizontal parallax might be the future response to these current limitations.
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