mdh.sePublications
Change search
Refine search result
1 - 36 of 36
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Abdul-Ahad, Amir Stefan
    et al.
    Lindén, Maria
    Mälardalen University, School of Innovation, Design and Engineering.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Mahmoud, Waleed A.
    Robust Distance-Based Watermarking for Digital Video2008In: Proceedings of The Annual SIGRAD Conference, Stockholm, 2008Conference paper (Refereed)
  • 2.
    Ameri E., Afshin
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. IS (Embedded Systems).
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. IS (Embedded Systems).
    Towards Full-Scale Ray Tracing in Games2016In: Proceedings of SIGRAD 2016, Visby, Sweden, 2016, Vol. 127, p. 48-49, article id 009Conference paper (Refereed)
    Abstract [en]

    We discuss the current status when it comes to real-time ray tracing of games as a full-scale alternative to renderers based on rasterization. Modern games include massive geometry, beautiful graphics, and advanced rendering effects, and still, they run with a high and steady frame rate at high resolutions. We argue that to make ray tracing a viable option, significant further development is required in terms of improved algorithms and software libraries, as well as hardware innovations that will greatly benefit the average gamer’s hardware equipment.

  • 3.
    Begum, Shahina
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Sandström, Kristian
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Towards a Compositional Service Architecture for Real-Time Cloud Robotics2016In: ACM SIGBED Review, E-ISSN 1551-3688, p. 63-64Article in journal (Refereed)
    Abstract [en]

    In this paper we present our ongoing work towards a compositional service architecture that integrates cloud technology for computational capacity targeting real-time robotics applications. In particular we take a look at the challenges inherent within the data center where the services are executing. We outline characteristics of the services used in the real-time cloud robotics application, along with the service management and corresponding task model used to execute services. We identify several key central challenges that must be addressed towards integrating cloud technology in real-time robotics.

  • 4.
    Capannini, Gabriele
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Adaptive Collision Culling for Large-Scale Simulations by a Parallel Sweep and Prune Algorithm2016In: Proceedings of the 16th Eurographics Symposium on Parallel Graphics and Visualization EGPGV 2016, Groningen, Netherlands: Eurographics Association , 2016, p. 1-10Conference paper (Refereed)
  • 5.
    Capannini, Gabriele
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Adaptive Collision Culling for Massive Simulations by a Parallel and Context-Aware Sweep and Prune Algorithm2018In: IEEE Transactions on Visualization and Computer Graphics, ISSN 1077-2626, E-ISSN 1941-0506, Vol. 4, no 7, p. 2064-2077Article in journal (Refereed)
    Abstract [en]

    We present an improved parallel Sweep and Prune algorithm that solves the dynamic box intersection problem in three dimensions. It scales up to very large datasets, which makes it suitable for broad phase collision detection in complex moving body simulations. Our algorithm gracefully handles high-density scenarios, including challenging clustering behavior, by using a double-axis sweeping approach and a cache-friendly succinct data structure. The algorithm is realized by three parallel stages for sorting, candidate generation, and object pairing. By the use of temporal coherence, our sorting stage runs with close to optimal load balancing. Furthermore, our approach is characterized by a work-division strategy that relies on adaptive partitioning, which leads to almost ideal scalability. In addition, for scenarios that involves intense clustering along several axes simultaneously, we propose an enhancement that increases the context-awareness of the algorithm. By exploiting information gathered along three orthogonal axes, an efficient choice of what range query to perform can be made per object during run-time. Experimental results show high performance for up to millions of objects on modern multi-core CPUs.

  • 6.
    Capannini, Gabriele
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Efficient Collision Culling by a Succinct Bi-dimensional Sweep and Prune Algorithm2016In: Proceedings of the 32nd Spring Conference on Computer Graphics, 2016, p. 25-32Conference paper (Refereed)
  • 7.
    Capannini, Gabriele
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. IS (Embedded Systems).
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. IS (Embedded Systems).
    Output Sensitive Collision Detection for Unisize Boxes2016In: Proceedings of SIGRAD 2016, Visby, Sweden, 2016, p. 22-27Conference paper (Refereed)
  • 8.
    Dodig Crnkovic, Gordana
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Game Ethics - Homo Ludens as a Computer Game Designer and Consumer2005In: International Review of Information Ethics, ISSN 1614-1687, E-ISSN 1614-1687, Vol. 4, no 12Article in journal (Refereed)
    Abstract [en]

    Play and games are among the basic means of expression in intelligent communication, influenced by the relevant cultural environment. Games have found a natural expression in the contemporary computer era in which communications are increasingly mediated by computing technology. The widespread use of e-games results in conceptual and policy vacuums that must be examined and understood. Humans involved in design-ing, administering, selling, playing etc. computer games encounter new situations in which good and bad, right and wrong, are not defined by the experience of previous generations. This article gives an account of the historical necessity of games, the development of e-games, their pros- and cons, threats and promises, focusing on the ethical awareness and attitudes of game developers.

  • 9. Jää-Aro, Kai-Mikael
    et al.
    Larsson, ThomasMälardalen University, School of Innovation, Design and Engineering.
    Proceedings of SIGRAD 2010: Content aggregation and visualization : November 25-26, 2010, Västerås, Sweden2010Conference proceedings (editor) (Other academic)
  • 10.
    Karlsson, Mattias
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Winberg, Olov
    Mälardalen University, School of Innovation, Design and Engineering.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Parallel Construction of Bounding Volumes2010In: The Annual SIGRAD Conference, Sweden, 2010Conference paper (Refereed)
  • 11.
    Källberg, Linus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Ray Tracing using Hierarchies of Slab Cut Balls2010In: Eurographics 2010, short papers, 2010, p. 69-72Conference paper (Refereed)
    Abstract [en]

    In this paper, bounding volume trees of slab cut balls are evaluated and compared with other types of trees for raytracing. A novel tree construction algorithm is proposed, which utilizes a relative orientation heuristic betweenparent and child nodes. Also, a fast intersection test between a ray and a slab cut ball is presented. Experimentalcomparisons to other commonly used enclosing shapes reveal that the slab cut ball is attractive. In particular, theslab cut ball outperforms the sphere in all tested scenes with speed-up factors between 1 and 4.

  • 12.
    Källberg, Linus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    A Filtering Heuristic for the Computation of Minimum-Volume Enclosing Ellipsoids2016In: Lecture Notes in Computer Science,, Hong Kong, China: Springer International Publishing , 2016, p. 744-753Conference paper (Refereed)
    Abstract [en]

    We study heuristics to accelerate existing state-of-the-art algorithms for the minimum-volume enclosing ellipsoid problem. We propose a new filtering heuristic that can significantly reduce the number of distance computations performed in algorithms derived from Khachiyan’s first-order algorithm. Our experiments indicate that in high dimensions, the filtering heuristic is more effective than the elimination heuristic proposed by Harman and Pronzato. In lower dimensions, the elimination heuristic is superior.

  • 13.
    Källberg, Linus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Accelerated Computation of Minimum Enclosing Balls by GPU Parallelization and Distance Filtering2014In: Proceedings of SIGRAD 2014 SIGRAD 2014, 2014Conference paper (Refereed)
    Abstract [en]

    Minimum enclosing balls are used extensively to speed up multidimensional data processing in, e.g., machine learning, spatial databases, and computer graphics. We present a case study of several acceleration techniques that are applicable in enclosing ball algorithms based on repeated farthest-point queries. Parallel GPU solutions using CUDA are developed for both low- and high-dimensional cases. Furthermore, two different distance filtering heuristics are proposed aiming at reducing the cost of the farthest-point queries as much as possible by exploiting lower and upper distance bounds. Empirical tests show encouraging results. Compared to a sequential CPU version of the algorithm, the GPU parallelization runs up to 11 times faster. When applying the distance filtering techniques, further speedups are observed.

  • 14.
    Källberg, Linus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Faster Approximation of Minimum Enclosing Balls by Distance Filtering and GPU Parallelization2015In: Journal of Graphics Tools, ISSN 2165-3488, Vol. 17, no 3, p. 67-84Article in journal (Refereed)
    Abstract [en]

    Minimum enclosing balls are used extensively to speed up multidimensional data processing in, e.g., machine learning, spatial databases, and computer graphics. We present a case study of several acceleration techniques that are applicable in enclosing ball algorithms based on repeated farthest-point queries. Two different distance filtering heuristics are proposed aiming at reducing the cost of the farthest-point queries as much as possible by exploiting lower and upper distance bounds. Furthermore, auto-tunable GPU solutions using CUDA are developed for both low- and high-dimensional cases. Empirical tests apply these techniques to two recent algorithms and demonstrate substantial speedups of the ball computations. Our results also indicate that a combination of the approaches has the potential to give further performance improvements.

  • 15.
    Källberg, Linus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Improved pruning of large data sets for the minimum enclosing ball problem2014In: Graphical Models, ISSN 1524-0703, E-ISSN 1524-0711, Vol. 76, no 6, p. 609-619Article in journal (Refereed)
    Abstract [en]

    Minimum enclosing ball algorithms are studied extensively as a tool in approximation and classification of multidimensional data. We present pruning techniques that can accelerate several existing algorithms by continuously removing interior points from the input. By recognizing a key property shared by these algorithms, we derive tighter bounds than have previously been presented, resulting in twice the effect on performance. Furthermore, only minor modifications are required to incorporate the pruning procedure. The presented bounds are independent of the dimension, and empirical evidence shows that the pruning procedure remains effective in dimensions up to at least 200. In some cases, performance improvements of two orders of magnitude are observed for large data sets. © 2014 Elsevier Inc. All rights reserved.

  • 16.
    Källberg, Linus
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Shellshear, E.
    Fraunhofer Chalmers Centre, Gothenburg, Sweden .
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    An external memory algorithm for the minimum enclosing ball problem2016In: VISIGRAPP 2016 - Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 2016, p. 83-90Conference paper (Refereed)
    Abstract [en]

    In this article we present an external memory algorithm for computing the exact minimum enclosing ball of a massive set of points in any dimension. We test the performance of the algorithm on real-life three-dimensional data sets and demonstrate for the first time the practical efficiency of exact out-of-core algorithms. By use of simple heuristics, we achieve near-optimal I/O in all our test cases.

  • 17.
    Larsson, Thomas
    Mälardalen University, Department of Computer Science and Engineering.
    Adaptive Algorithms for Collision Detection and Ray Tracing of Deformable Meshes2003Licentiate thesis, comprehensive summary (Other scientific)
  • 18.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Adaptive Bounding Volume Hierarchies for Efficient Collision Queries2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The need for efficient interference detection frequently arises in computer graphics, robotics, virtual prototyping, surgery simulation, computer games, and visualization. To prevent bodies passing directly through each other, the simulation system must be able to track touching or intersecting geometric primitives. In interactive simulations, in which millions of geometric primitives may be involved, highly efficient collision detection algorithms are necessary. For these reasons, new adaptive collision detection algorithms for rigid and different types of deformable polygon meshes are proposed in this thesis. The solutions are based on adaptive bounding volume hierarchies.

    For deformable body simulation, different refit and reconstruction schemes to efficiently update the hierarchies as the models deform are presented. These methods permit the models to change their entire shape at every time step of the simulation. The types of deformable models considered are (i) polygon meshes that are deformed by arbitrary vertex repositioning, but with the mesh topology preserved, (ii) models deformed by linear morphing of a fixed number of reference meshes, and (iii) models undergoing completely unstructured relative motion among the geometric primitives. For rigid body simulation, a novel type of bounding volume, the slab cut ball, is introduced, which improves the culling efficiency of the data structure significantly at a low storage cost. Furthermore, a solution for even tighter fitting heterogeneous hierarchies is outlined, including novel intersection tests between spheres and boxes as well as ellipsoids and boxes. The results from the practical experiments indicate that significant speedups can be achieved by using these new methods for collision queries as well as for ray shooting in complex deforming scenes.

     

  • 19.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    An Efficient Ellipsoid-OBB Intersection Test2008In: Journal of Graphics Tools, ISSN 1086-7651, Vol. 13, no 1, p. 31-43Article in journal (Refereed)
    Abstract [en]

    An efficient algorithm to determine the intersection status between arbitrarily oriented ellipsoids and boxes (OBBs) is presented. By choosing a proper representation of the geometric objects and by utilizing an affine transformation of space, the problem is converted into a corresponding sphere-parallelepiped intersection test. Thereby, the evaluation of more costly mathematical operations other than a constant number of simple arithmetic operations and comparisons can be avoided. Further efficiency is also gained by exploiting the regularity of the involved geometric shapes, as well as early rejection tests. Practical experiments show a four-times speed-up on average when these techniques are used.

  • 20.
    Larsson, Thomas
    Mälardalen University, School of Innovation, Design and Engineering.
    Fast and Tight Fitting Bounding Spheres2008In: Proceedings of the Annual SIGRAD Conference, Stockholm, Linköping: Linköping University Electronic Press, 2008, Vol. 34, p. 27-30Conference paper (Refereed)
    Abstract [en]
    • Abstract
    • References
    • Citations in
    • Citations in Google Scholar

    Bounding spheres are utilized frequently in many computer graphics and visualization applications; and it is not unusual that the computation of the spheres has to be done during run-time at real-time rates. In this paper; an attractive algorithm for computing bounding spheres under such conditions is proposed. The method is based on selecting a set of k extremal points along s = k/2 input directions. In general; the method is able to compute better fitting spheres than Ritter’s algorithm at roughly the same speed. Furthermore; the algorithm computes almost optimal spheres significantly faster than the best known smallest enclosing ball methods. Experimental evidence is provided which illustrates the qualities of the approach as compared to five other competing methods. Also; the experimental result gives insight into how the parameter s affects the tightness of fit and computation speed.

    CR Categories: F.2.2 [Analysis of Algorithms and Problem Complexity]: Nonnumerical Algorithms and Problems—Geometrical problems and computations; I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling

    Keywords: Bounding sphere; enclosing ball; extremal points; computational geometry; computer graphics

  • 21.
    Larsson, Thomas
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Akenine-Möller, Tomas
    Lund University, Sweden.
    A dynamic bounding volume hierarchy for generalized collision detection2006In: Computers & Graphics, ISSN 0097-8493, Vol. 30, no 3, p. 451-460Article in journal (Refereed)
    Abstract [en]

    In this paper, we propose a new dynamic and efficient bounding volume hierarchy for breakable objects undergoing structured and/or unstructured motion. Our object-space method is based on different ways to incrementally update the hierarchy during simulation by exploiting temporal coherence and lazy evaluation techniques. This leads to significant advantages in terms of execution speed. Furthermore, we also show how our method lends itself naturally for an adaptive low memory cost implementation, which may be of critical importance in some applications. Finally, we propose two different techniques for detecting self-intersections, one using our hierarchical data structure, and the other is an improved sorting-based method.

  • 22.
    Larsson, Thomas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Akenine-Möller, Tomas
    Lund University.
    Bounding Volume Hierarchies of Slab Cut Balls2009In: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, Vol. 28, no 8, p. 2379-2395Article in journal (Refereed)
    Abstract [en]

    We introduce a bounding volume hierarchy based on the Slab Cut Ball. This novel type of enclosing shape provides an attractive balance between tightness of fit, cost of overlap testing, and memory requirement. The hierarchy construction algorithm includes a new method for the construction of tight bounding volumes in worst case O(n) time, which means our tree data structure is constructed in O(n log n) time using traditional top-down building methods. A fast overlap test method between two slab cut balls is also proposed, requiring as few as 28-99 arithmetic operations, including the transformation cost. Practical collision detection experiments confirm that our tree data structure is amenable for high performance collision queries. In all the tested benchmarks, our bounding volume hierarchy consistently gives performance improvements over the sphere tree, and it is also faster than the OBB tree in five out of six scenes. In particular, our method is asymptotically faster than the sphere tree, and it also outperforms the OBB tree, in close proximity situations.

  • 23.
    Larsson, Thomas
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Akenine-Möller, Tomas
    Lund University, Sweden.
    Lengyel, Eric
    Terathon Software.
    On Faster Sphere-Box Overlap Testing2007In: Journal of graphics tools, ISSN 2165-347X, Vol. 12, no 1, p. 3-8Article in journal (Refereed)
    Abstract [en]

    We present faster overlap tests between spheres and either axis-aligned or oriented boxes. By utilizing quick rejection tests, faster execution times are observed compared to previous techniques. In addition, we present alternative vectorized overlap tests, which are compared to the sequential algorithms. Source code is available online.

  • 24.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Exact Bounding Spheres by Iterative Octant Scan2015In: Proceedings of SIGRAD 2015 SIGRAD 2015, Stockholm, Sweden: Linköping University Electronic Press , 2015, p. 9-12Conference paper (Refereed)
    Abstract [en]

    We propose an exact minimum bounding sphere algorithm for large point sets in low dimensions. It aims to reduce the number of required passes by retrieving a well-balanced set of outliers in each linear search through the input. The behaviour of the algorithm is mainly studied in the important three-dimensional case. The experimental evidence indicates that the convergence rate is superior compared to previous exact methods, which effectively results in up to three times as fast execution times. Furthermore, the run times are not far behind simple 2-pass constant approximation heuristics.

  • 25.
    Larsson, Thomas B
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Capannini, Gabriele
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Källberg, Linus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Parallel computation of optimal enclosing balls by iterative orthant scan2016In: Computers & graphics, ISSN 0097-8493, E-ISSN 1873-7684, Vol. 56, p. 1-10Article in journal (Refereed)
    Abstract [en]

    We propose an algorithm for computing the exact minimum enclosing ball of large point sets in general dimensions. It aims to reduce the number of passes by retrieving a well-balanced set of outliers in each linear search through the input by decomposing the space into orthants. The experimental evidence indicates that the convergence rate in terms of the required number of linear passes is superior compared to previous exact methods, and substantially faster execution times are observed in dimensions d≤16. In the important three-dimensional case, the execution times indicate real-time performance. Furthermore, we show how the algorithm can be adapted for parallel execution on both CPU and GPU architectures using OpenMP, AVX, and CUDA. For large datasets, our CUDA solution is superior. For example, the benchmark results show that optimal bounding spheres for inputs with tens of millions of points can be computed in just a few milliseconds.

  • 26.
    Larsson, Thomas B
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Källberg, Linus
    Mälardalen University, School of Innovation, Design and Engineering.
    Fast and robust approximation of smallest enclosing balls in arbitrary dimensions2013In: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, Vol. 32, no 5, p. 93-101Article in journal (Refereed)
    Abstract [en]

    In this paper, an algorithm is introduced that computes an arbitrarily fine approximation of the smallest enclosing ball of a point set in any dimension. This operation is important in, for example, classification, clustering, and data mining. The algorithm is very simple to implement, gives reliable results, and gracefully handles large problem instances in low and high dimensions, as confirmed by both theoretical arguments and empirical evaluation. For example, using a CPU with eight cores, it takes less than two seconds to compute a 1.001-approximation of the smallest enclosing ball of one million points uniformly distributed in a hypercube in dimension 200. Furthermore, the presented approach extends to a more general class of input objects, such as ball sets. 

  • 27.
    Larsson, Thomas
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Flemström, Daniel
    Mälardalen University, Department of Computer Science and Electronics.
    Improving Introductory Programming Courses by Using a Simple Accelerated Graphics Library2007In: SIGRAD 2007: Conference Proceedings, 2007, p. 24-30Conference paper (Refereed)
    Abstract [en]

    We present a platform independent and hardware accelerated graphics library, which has been found to be a suitable educational tool for novice programmers. The purpose of the library is to change the nature of the assignments and projects used in introductory programming courses to something that fascinate and stimulate the students, e.g., game creation. We describe our experiences from using the presented graphics library in four different course instances of our introductory C++ course. The course surveys show that most students found the approach interesting and fun. As faculty, we could clearly see how many students became highly engaged in their projects and some of them accomplished solutions way beyond our expectations. In particular, compared to the programming courses we have given in the past, in which a standard framework for creating window applications was used, we have noticed a significant improvement in terms of the quality of the students' project solutions.

  • 28.
    Larsson, Thomas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Kjelldahl, LarsJää-Aro, Kai-Mikael
    Proceedings of SIGRAD 2011. Evaluations of Graphics and Visualization: Efficency, Usefulness, Accessibility, Usability2011Conference proceedings (editor) (Other academic)
  • 29.
    Larsson, Thomas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Källberg, Linus
    Mälardalen University, School of Innovation, Design and Engineering.
    Fast Computation of Tight-Fitting Oriented Bounding Boxes2011In: Game Engine Gems 2, A K Peters/CRC Press , 2011, p. 3-19Chapter in book (Other academic)
    Abstract [en]

    Figure 1.1. Computed boxes for a simple cube mesh (12 triangles) and star mesh (16 triangles). The first column shows the AABB, the second column shows the OBB computed by PCA, and the last column shows the OBB computed by DiTO. The meshes were randomly rotated before the computation. 

  • 30.
    Larsson, Thomas
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Stenlund, Ulf
    Mälardalen University, School of Innovation, Design and Engineering.
    Vignettes of Sweden's Computer Graphics History2008In: IEEE Annals of the History of Computing, ISSN 1058-6180, E-ISSN 1934-1547, Vol. 30, no 1, p. 50-58Article in journal (Refereed)
    Abstract [en]

    This article recounts selected historical events in the computer graphics field in Sweden, ranging from hardware construction to human-computer interaction. Particularly noteworthy are the industrial developments of semigraphical interfaces for improved man-machine communication, and the patented invention of a color graphics system by Hakan Lans, which gave rise to several court cases.

  • 31.
    Sabouri, Peyman
    et al.
    Auckland University of Technology, New Zealand.
    Gholam Hosseini, Hamid
    Auckland University of Technology, New Zealand.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Collins, John
    Auckland University of Technology, New Zealand.
    A Cascade Classifier for Diagnosis of Melanoma in Clinical Images2014In: The 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society IEEE EMBC14, 2014, p. 6748-6751Conference paper (Refereed)
    Abstract [en]

    Computer aided diagnosis of medical images can help physicians in better detecting and early diagnosis of many symptoms and therefore reducing the mortality rate. Realization of an efficient mobile device for semi-automatic diagnosis of melanoma would greatly enhance the applicability of medical image classification scheme and make it useful in clinical contexts. In this paper, interactive object recognition methodology is adopted for border segmentation of clinical skin lesion images. In addition, performance of five classifiers, KNN, Naïve Bayes, multi-layer perceptron, random forest and SVM are compared based on color and texture features for discriminating melanoma from benign nevus. The results show that a sensitivity of 82.6% and specificity of 83% can be achieved using a single SVM classifier. However, a better classification performance was achieved using a proposed cascade classifier with the sensitivity of 83.06% and specificity of 90.05% when performing ten-fold cross validation.

  • 32.
    Stålberg, Anna
    et al.
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Sandberg, Anette
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Coyne, Imelda
    Trinity Coll Dublin, Sch Nursing & Midwifery, Dublin, Ireland..
    Larsson, Thomas B
    Söderbäck, Maja
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Using an interactive communication tool in healthcare situations: Patterns in young children's use of participation cues2019In: Journal of Child Health Care, ISSN 1367-4935, E-ISSN 1741-2889, article id UNSP 1367493518814928Article in journal (Refereed)
    Abstract [en]

    This study forms part of a larger project about developing and using interactive technology to facilitate young children's participation in healthcare situations. Children's participation in these situations improves their motivation and situated understanding. Likewise, their participation helps professionals to more fully understand the child's perspective. In the project, an interactive communication tool, that is, an application suitable for tablet use, was developed with children, aged three to five, in two clinical settings. When tested, the children's participation cues, identified from video recordings of healthcare situations, were understood as having curious, thoughtful or affirmative meanings. This study aimed to investigate the similarities and differences in the young children's use of participation cues when using an interactive communication tool in healthcare situations. A secondary analysis of the identified cues was performed focusing on age, setting and examination or procedure. In total, 2167 cues were identified representing either curious, thoughtful or affirmative cues. The curious cues were mainly used (66%), followed by thoughtful (28%) and affirmative (6%) cues. Differences in cue usage were seen in relation to the children's age and setting. Knowing how children may react to common healthcare procedures may help increase healthcare professionals' awareness of the need to support children in an individual and situational way.

  • 33.
    Stålberg, Anna
    et al.
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Sandberg, Anette
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Imelda, Coyne
    Trinity College, Dublin, Ireland.
    Söderbäck, Maja
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Curious, Thoughtful and Affirmative – Young Children’s Meanings of Participation in Healthcare Situations when using an Interactive Communication Tool2017In: Journal of Clinical Nursing, ISSN 0962-1067, E-ISSN 1365-2702, Vol. 27, no 1-2, p. 235-246Article in journal (Refereed)
  • 34.
    Stålberg, Anna
    et al.
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Sandberg, Anette
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Söderbäck, Maja
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    The child’s perspective as a guiding principle: Young children as co-designers in the design of an interactive application meant to facilitate participation in healthcare situations2016In: Journal of Biomedical Informatics, ISSN 1532-0464, E-ISSN 1532-0480, Vol. 61, p. 149-158Article in journal (Refereed)
    Abstract [en]

    During the last decade, interactive technology has entered mainstream society. Its many users also include children, even the youngest ones, who use the technology in different situations for both fun and learning. When designing technology for children, it is crucial to involve children in the process in order to arrive at an age-appropriate end product. In this study we describe the specific iterative process by which an interactive application was developed. This application is intended to facilitate young children's, three-to five years old, participation in healthcare situations. We also describe the specific contributions of the children, who tested the prototypes in a preschool, a primary health care clinic and an outpatient unit at a hospital, during the development process. The iterative phases enabled the children to be involved at different stages of the process and to evaluate modifications and improvements made after each prior iteration. The children contributed their own perspectives(the child's perspective) on the usability, content and graphic design of the application, substantially improving the software and resulting in an age-appropriate product.

  • 35.
    Stålberg, Anna
    et al.
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Söderbäck, Maja
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    Sandberg, Anette
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Larsson, Thomas B
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    The child’s perspective as the guiding principle: young children as co-designers of an application used for enabling participation in healthcare situations2016Conference paper (Refereed)
    Abstract [en]

    Introduction: To facilitate child´s rights in healthcare situations, professionals need to be aware of, and use, their child perspective and the child´s perspective in the situation. A child´s rights approach requires that the caring culture and ways of working are adapted to the interactive communication tool, based on children´s perceptions of being in healthcare situations, prerequisites of children.

    Aim: To develop an interactive communication tool, based on children´s perceptions of being in healthcare situations, meant to facilitate children´s participation and understanding in these specific situations.

    Method: Children, 3-5 years, in a preschool, a primary health care clinic and a pediatric outpatient unit at a hospital were encountered in interviews which focused the children´s perceptions of being in healthcare situations. Non-verbal perceptions were elicited through drawings. These perceptions were used in the development of the communication tool. In iterative phases the children, as co-designers, tested and evaluated evolving prototypes of the tool. Their feedback were analyzed and used in the ongoing development and improvement of the prototype.

    Result: an iterative, co-designing process of the interactive communication tool transformed children´s verbal and non-verbal perceptions of being in a healthcare situation into an age appropriate and likeable application regarding content, usability and graphic design.

    Conclusion: an interactive communication tool involving visual guidance of healthcare situations facilitates younger children to elicit their perspective in these situations. Children´s participation in healthcare situations is enabled by professionals who use the child´s perspective, expressed with help of the communication tool, combined with their verbal guidance.

  • 36.
    Yrjölä, Kristian
    et al.
    Mälardalen University, Department of Computer Science and Electronics.
    Larsson, Thomas
    Mälardalen University, Department of Computer Science and Electronics.
    Real-time Generation of Plausible Surface Waves2007Conference paper (Refereed)
    Abstract [en]

    We present a fast and flexible algorithm for the simulation and rendering of ocean waves. The method is designed to support efficient view frustum culling and various simple wave effects such as choppy waves, capillary waves, wave refraction, round waves, and wave-land interaction, which makes the model suitable in, e.g., computer games. The waves are numerically robust, and the execution time of the generated waves can be controlled dynamically. Finally, experimental results illustrate the interactive performance and the visual quality of the generated waves.

1 - 36 of 36
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf