| 1. |
- Eriksson, Patric, et al.
(author)
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A role for 'sensor simulation' and 'pre-emptive learning' in computer aided robotics
- 1995
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In: 26th International Symposium on Industrial Robots, Symposium Proceedings. - : Mechanical Engineering Publ.. - 1860580009 ; , s. 135-140
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Conference paper (peer-reviewed)abstract
- Sensor simulation in Computer Aided Robotics (CAR) can enhance the capabilities of such systems to enable off-line generation of programmes for sensor driven robots. However, such sensor simulation is not commonly supported in current computer aided robotic environments. A generic sensor object model for the simulation of sensors in graphical environments is described in this paper. Such a model can be used to simulate a variety of sensors, for example photoelectric, proximity and ultrasonic sensors. Tests results presented here show that this generic sensor model can be customised to emulate the characteristics of the real sensors. The preliminary findings from the first off-line trained mobile robot are presented. The results indicate that sensor simulation within CARs can be used to train robots to adapt to changing environments.
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| 2. |
- Eriksson, Magnus
(author)
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Internet och multimedia
- 1996
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In: Grunderna i IT. - Stockholm : Utbildningsradion. - 9126963949 ; , s. 12-25
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Book chapter (other academic/artistic)abstract
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| 3. |
- Lindeberg, Tony, 1964-, et al.
(author)
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Analysis of brain activation patterns using a 3-D scale-space primal sketch
- 1999
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In: Human Brain Mapping. - 1065-9471 .- 1097-0193. ; 7:3, s. 166-94
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Journal article (peer-reviewed)abstract
- A fundamental problem in brain imaging concerns how to define functional areas consisting of neurons that are activated together as populations. We propose that this issue can be ideally addressed by a computer vision tool referred to as the scale-space primal sketch. This concept has the attractive properties that it allows for automatic and simultaneous extraction of the spatial extent and the significance of regions with locally high activity. In addition, a hierarchical nested tree structure of activated regions and subregions is obtained. The subject in this article is to show how the scale-space primal sketch can be used for automatic determination of the spatial extent and the significance of rCBF changes. Experiments show the result of applying this approach to functional PET data, including a preliminary comparison with two more traditional clustering techniques. Compared to previous approaches, the method overcomes the limitations of performing the analysis at a single scale or assuming specific models of the data.
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| 4. |
- Åkerman, S., et al.
(author)
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Surface Model Generation and Segmentation of the Human Celebral Cortex for the Construction of Unfolded Cortical Maps
- 1996
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In: Proc. 2nd International Conference on Functional Mapping of the Human Brain. ; , s. S126-S126
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Conference paper (peer-reviewed)abstract
- Representing the shape of the human cerebral cortex arises as a basic subproblem in several areas of brain science, such as when describing the anatomy of the cortex and when relating functional measurements to cortical regions. Most current methods for building such representions of the cortical surface are either based on contours from two-dimensional cross sections or landmarks that have been obtained manually.In this article, we outline a methodology for semi-automatic contruction of a solely surface based representation of the human cerebral cortex in vivo for subsequent generation of (unfolded) two-dimensional brain maps.The method is based on input data in the form of three-dimensional NMR images, and comprises the following main steps:suppression of disturbing fine-scale structures by linear and non-linear scale-space techniques,generation of a triangulated surface representation based on either iso-surfaces or three-dimensional edge detection,division of the surface model into smaller segments based on differential invariants computed from the image data.When constructing an unfolded (flattened) surface representation, the instrinsic curvature of the cortex means that such a unfolding cannot be done without introducing distortions. To reduce this problem, we propose to cut the surface into smaller parts, where a ridge detector acts as guideline, and then unfold each patch individually, so as to obtain low distortions.Having a solely surface based representation of the cortex and expressing the image operations using multi-scale differential invariants in terms of scale-space derivatives as done in this work is a natural choice both in terms of conceptual and algorithmic simplicity. Moreover, explicitly handling the multi-scale nature of the data is necessary to obtain robust results.
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| 5. |
- Ujvari, Sandor, 1972-, et al.
(author)
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Simulation and emulation of sensor systems for intelligent vehicles
- 1998
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In: Mechatronics '98. - : Pergamon Press. - 0080433391 ; , s. 385-390
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Conference paper (peer-reviewed)abstract
- Simulation of sensor systems for mobile robots are described in this paper. By simulation of smart sensor systems, the performance of semi-autonomous vehicles / mobile robots can be enhanced. Smart sensor systems used in the field of mobile robotics can utilise adaptive algorithms. e. g. artificial neural nets, fuzzy logic or hybrid variants of these systems. The development, training and evaluation of adaptive algorithms for sensor systems can be done within a virtual environment in which graphical models are built to simulate an intelligent vehicle, its sensors, and its environment. The virtual sensors are validated by comparing the characteristics of the virtual sensors with those of the real devices.
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| 6. |
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| 7. |
- Eriksson, Magnus, et al.
(author)
-
Dynamic Radio Resource Management Schemes for Interactive Services in DVB-T and DAB
- 1999
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In: Proceedings of Radiovetenskap och kommunikation. - Karlskrona : Högskolan i Karlskrona/Ronneby. - 9163081563
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Conference paper (other academic/artistic)abstract
- The topic of this paper is dynamic schemes for downlink packet radio resource management. The results can be applied to personal communication services in the terrestrial digital video and audio broadcasting systems (DVB-T and DAB). Dynamic single frequency networks (DSFN) are investigated, meaning that the macro diversity capability of the COFDM modulation scheme is utilised for cellular communication. The concept of PARPS (Packet and Resource Plan Scheduling) is introduced. PARPS reduces the combined problem of dynamic radio resource management, including DSFN, dynamic channel allocation, power control, link adaptation, etc, to a scheduling problem. We propose several optimised and heuristic PARPS schemes. Our results show that some of the heuristic schemes have near-optimal delay performance. We also have results indicating that the capacity of the PARPS schemes for 2D Poisson traffic can be evaluated with static analyses, i.e. without simulation of a queuing system.
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| 8. |
- Eriksson, Magnus, et al.
(author)
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The Concepts of PARPS : Packet and Resource Plan Scheduling
- 1999
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In: Multiaccess, Mobility and Teletraffic for Wireless Communications (MMT '99), Venice, Italy, October 6-8, 1999.
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Conference paper (other academic/artistic)abstract
- Dynamic schemes for downlink packet radio resource management (RRM) are the topic of this paper. The concept of PARPS (Packet And Resource Plan Scheduling) is introduced. PARPS reduces the combined proble m of dynamic RRM, including statistical multiplex, dynamic channel allocation, power control, link adaptation, reuse partitioning, soft handover, admission control, etc, to a scheduling problem. PARPS makes it possible to achieve dynamic RRM individually for each data packet, without performing signal-to-interference ratio calculations for every single packet. A PARPS algorithm assigns a so-called resource plan to each timeslot, and assigns data packets to timeslots and transmitters. A resource plan is a combination of several radio parameters, e.g. transmitter power levels, coding rates and modulation schemes, for a group of centrally controlled and synchronised transmitters. We propose several optimised and heuristic PARPS algorithms. Optimised PARPS is NP hard, i.e. it is not realistic to solve in real time for a big system, but it can be used for finding an upper bound for the compound effect of several RRM techniques by means of computer simulations. The heuristic algorithms are realistic to implement in real systems. Our results show that some of the heuristic algorithms have delay performance very near an optimised algorithm, and that the capacity and coverage of a set of resource plans for 2D Poisson traffic can be evaluated with static analyses, i.e. without queuing system simulation. We apply PARPS to cellular systems based on the COFDM modulation scheme. Especially, we have personal communication services in the MEMO system in mind, where the terrestrial digital audio or video broadcasting system (DAB or DVB-T) is used as a broadband downlink, in combination with some narrowband uplink, e.g. GSM.
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| 9. |
- Lindeberg, Tony, 1964-
(author)
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On the behaviour in scale-space of local extrema and blobs
- 1991
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In: Theory and Applications of Image Analysis. - : World Scientific. ; , s. 38-47, s. 8-17
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Book chapter (peer-reviewed)abstract
- We apply elementary techniques from real analysis and singularity theory to derive analytical results for the behaviour in scale-space of critical points and related entities. The main results of the treatment comprise: a description of the general nature of trajectories of critical points in scale-space. an estimation of the drift velocity of critical points and edges. an analysis of the qualitative behaviour of critical points in bifurcation situations. a classification of what types of blob bifurcations are possible.
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| 10. |
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