| 11. |
- Broxvall, Mathias, 1976-, et al.
(författare)
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Developing Medical Image Processing Algorithms for GPU assisted parallel computation
- 2013
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Ingår i: Computer Vision in Medical Imaging. - : World Scientific. - 9789814460934 - 9789814460958 ; , s. 245-270
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Bokkapitel (refereegranskat)abstract
- GPU’s have recently emerged as a significantly more powerful computing plat-form, capable of several orders of magnitude faster computations compared toCPU based approaches. However, they require significant changes in the algorithmic design compared to traditional programming paradigms. In this chapter we specifically introduce the reader to an overview of GPGPU development tools and the potential algorithmic pitfalls and bottlenecks when developing medical imaging algorithms for the GPU. We present a few general methodologies and building blocks for implementing fast image processing on GPUs. More specifically they include: methods for performing fast image convolutions and filtering;line detection, and bandwidth and memory considerations when processing volumetric datasets. Finally we conclude with a discourse on numerical precision as well as on mixing single floating-point versus double floating-point code.
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| 12. |
- Broxvall, Mathias, 1976-, et al.
(författare)
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Fast GPU based adaptive filtering of 4D echocardiography
- 2012
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Ingår i: IEEE Transactions on Medical Imaging. - Piscataway, USA : Institute of Electrical and Electronics Engineers (IEEE). - 0278-0062 .- 1558-254X. ; 31:6, s. 1165-1172
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Tidskriftsartikel (refereegranskat)abstract
- Time resolved three-dimensional (3D) echocardiography generates four-dimensional (3D+time) data sets that bring new possibilities in clinical practice. Image quality of four-dimensional (4D) echocardiography is however regarded as poorer compared to conventional echocardiography where time-resolved 2D imaging is used. Advanced image processing filtering methods can be used to achieve image improvements but to the cost of heavy data processing. The recent development of graphics processing unit (GPUs) enables highly parallel general purpose computations, that considerably reduces the computational time of advanced image filtering methods. In this study multidimensional adaptive filtering of 4D echocardiography was performed using GPUs. Filtering was done using multiple kernels implemented in OpenCL (open computing language) working on multiple subsets of the data. Our results show a substantial speed increase of up to 74 times, resulting in a total filtering time less than 30 s on a common desktop. This implies that advanced adaptive image processing can be accomplished in conjunction with a clinical examination. Since the presented GPU processor method scales linearly with the number of processing elements, we expect it to continue scaling with the expected future increases in number of processing elements. This should be contrasted with the increases in data set sizes in the near future following the further improvements in ultrasound probes and measuring devices. It is concluded that GPUs facilitate the use of demanding adaptive image filtering techniques that in turn enhance 4D echocardiographic data sets. The presented general methodology of implementing parallelism using GPUs is also applicable for other medical modalities that generate multidimensional data.
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| 13. |
- Broxvall, Mathias, et al.
(författare)
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Have another look on failures and recovery planning in perceptual anchoring
- 2004
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Konferensbidrag (refereegranskat)abstract
- An important requirement for autonomous systems is the ability to detect and recover from exceptional situations such as failures in observations. In this paper we demonstrate how techniques for planning with sensing under uncertainty can play a major role in solving the problem of recovering from such situations. In this first step we concentrate on failures in perceptual anchoring, that is how to connect a symbol representing an object to the percepts of that object. We provide a classification of failures and present planning-based methods for recovering from them. We illustrate our approach by showing tests run on a mobile robot equipped with a color camera.
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| 14. |
- Broxvall, Mathias, et al.
(författare)
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PEIS ecology : integrating robots into smart environments
- 2006
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Ingår i: 2006 IEEE International Conference on Robotics and automation, ICRA 2006. - 0780395050 ; , s. 212-218
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Konferensbidrag (refereegranskat)abstract
- We introduce the concept of Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology. This is a network of heterogeneous robotic devices (PEIS) pervasively embedded in the environment. A PEIS can be as simple as a toaster and as complex as a humanoid robot. PEIS can exchange information at different levels of abstraction, and share both physical and virtual functionalities to perform complex tasks. By putting together insights from the fields of autonomous robotics and of ambient intelligence, the PEIS-Ecology approach explores a new road to building assistive, personal, and service robots. In this paper, we discuss this concept, describe a first realization of it, and show an implemented use-case scenario.
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| 15. |
- Broxvall, Mathias, et al.
(författare)
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Recovery planning for ambiguous cases in perceptual anchoring
- 2005
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Ingår i: Proceedings of the 20th national conference on Artificial intelligence, AAAI-05. - 9781577352365 ; , s. 1254-1260
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Konferensbidrag (refereegranskat)abstract
- An autonomous robot using symbolic reasoning, sensing and acting in a real environment needs the ability to create and maintain the connection between symbols representing objects in the world and the corresponding perceptual representations given by its sensors. This connection has been named perceptual anchoring. In complex environments, anchoring is not always easy to establish: the situation may often be ambiguous as to which percept actually corresponds to a given symbol. In this paper, we extend perceptual anchoring to deal robustly with ambiguous situations by providing general methods for detecting them and recovering from them. We consider different kinds of ambiguous situations and present planning-based methods to recover from them. We illustrate our approach by showing experiments involving a mobile robot equipped with a color camera and an electronic nose.
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| 16. |
- Broxvall, Mathias, et al.
(författare)
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Steps toward detecting and recovering from perceptual failures
- 2004
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Ingår i: Proceedings of the 8th international conference on intelligent autonomous systems. ; , s. 793-800
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Konferensbidrag (refereegranskat)abstract
- An important requirement for autonomous systems is the ability to detect and recover from exceptional situations such as failures in observations. In this paper we investigate how traditional AI planning techniques can be used to reason about observations and to recover from these situations. In this first step we concentrate on failures in perceptual anchoring. We illustrate our approach by showing experiments run on a mobile robot equipped with a color camera.
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| 17. |
- Broxvall, Mathias, et al.
(författare)
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The PEIS kernel : a middleware for ubiquitous robotics
- 2007
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Konferensbidrag (refereegranskat)abstract
- The fields of autonomous robotics and ambient intelligence are converging toward the vision of smart robotic environments, or ubiquitous robotics, in which tasks are performed via the cooperation of many simple networked robotic devices. The concept of Ecology of Physically Embedded Intelligent Systems, or PEIS-Ecology, combines insights from these fields to provide a new solution to building intelligent robots in the service of people. To enable this vision, we need a common communication and cooperation model that allows dynamically assembled ad hoc networks of robotic devices, a flexible introspection and configuration model allowing automatic (re)configuration and that can be shared between robotic devices at different scales, ranging from standard mobile robots to tiny networked embedded devices. In this paper we discuss the development of a middleware suitable for ubiquitous robotics in general and P PEIS -Ecologies in specific. Our middleware is suitable for building truly ubiquitous robotics applications, in which devices of very different scales and capabilities can cooperate in a uniform way. We discuss the principles and implementation of our middleware, and also point to experimental results that show the viability of this concept.
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| 18. |
- d. C. Silva-Lopez, Lia Susana, 1985-, et al.
(författare)
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Towards configuration planning with partially ordered preferences : representation and results
- 2015
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Ingår i: Künstliche Intelligenz. - : Springer Berlin/Heidelberg. - 0933-1875 .- 1610-1987. ; 9:2, s. 173-183
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Tidskriftsartikel (refereegranskat)abstract
- Configuration planning for a distributed robotic system is the problem of how to configure the system over time in order to achieve some causal and/or information goals. A configuration plan specifies what components (sensor, actuator and computational devices), should be active at different times and how they should exchange information. However, not all plans that solve a given problem need to be equally good, and for that purpose it may be important to take preferences into account. In this paper we present an algorithm for configuration planning that incorporates general partially ordered preferences. The planner supports multiple preference categories, and hence it solves a multiple-objective optimization problem: for a given problem, it finds all possible valid, non-dominated configuration plans. The planner has been able to successfully cope with partial ordering relations between quantitative preferences in practically acceptable times, as shown in the empirical results. Preferences here are represented as c-semirings, and are used for establishing dominance of a solution over another in order to obtain a set of configuration plans that will constitute the solution of a configuration planning problem with partially ordered preferences. The dominance operators tested in this paper are Pareto and Lorenz dominance. Our solver considers one guiding heuristic for obtaining the first solution, and then switches to a dominance based monotonically decreasing heuristic used for pruning dominated partial configuration plans. In our empirical results, we perform a statistical study in the space of problem instances and establish families of problems for which our approach is computationally feasible.
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| 19. |
- Dragone, Mauro, et al.
(författare)
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A Programming Framework for Multi-agent Coordination of Robotic Ecologies
- 2013
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Ingår i: Programming Multi-Agent Systems. - Berlin, Heidelberg : Springer Publishing Company. - 9783642387005 ; , s. 72-89
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Konferensbidrag (refereegranskat)abstract
- Building smart environments with Robotic ecologies, comprising of distributed sensors, actuators and mobile robot devices facilitates and extends the nature and form of smart environments that can be developed, and reduces the complexity and cost of such solutions. While the potentials of such an approach makes robotic ecologies increasingly popular, many fundamental research questions remain open. One such question is how to make a robotic ecology self-adaptive, so as to adapt to changing conditions and evolving requirements, and consequently reduce the amount of preparation and pre-programming required for their deployment in real world applications. This paper presents a framework for the specification and the programming of robotic ecologies. The framework extends an existing agent system and integrates it with the pre-existing and dominant traditional robotic and middleware approach to the development of robotic ecologies. We illustrate how these technologies complement each other and offer a candidate technology to pursue adaptive robotic ecologies.
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| 20. |
- Gritti, Marco, et al.
(författare)
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Reactive self-configuration of an ecology of robots
- 2007
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Konferensbidrag (refereegranskat)abstract
- The field of ubiquitous robotics is burgeoning, and different brands of massively distributed heterogeneous robotic systems are being proposed and applied to several domains. The strong added value of these systems comes from their potential ability to dynamically self-configure, by changing the form of their cooperation to adapt to a given task or situation. In face of this, no satisfactory solution exists to the problem of how such a system should self-configure. In this paper, we explore a reactive approach to self-configuration inspired by ideas from the field of semantic web services. We illustrate our approach on a specific type of ubiquitous robot system, called PEIS-Ecology. We show experiments in which our approach autonomously generates a configuration to perform a cooperative navigation task, and dynamically changes this configuration when one of the components fails.
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