| 1. |
- Forsberg, Håkan, 1969-, et al.
(författare)
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Opportunities for Optical Planar Interconnection Technology in Terabit Switches
- 2003
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Ingår i: Proceedings of the IASTED International Conference on Wireless and Optical Communications, July 2-4, 2003, Banff, Canada. - Anaheim; Calgary : ACTA Press. - 0889863741 - 9780889863743 ; , s. 155-164
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Konferensbidrag (refereegranskat)abstract
- To keep up with the explosive growth of world-wide network traffic, large-capacity switches, with switching capacities in excess of several terabits per second, are becoming an essential part of the future. To realize such switches, new architecture concepts must be considered. In this paper, we discuss a technology for terabit switches that combines the advantage of using optical communication in all three spatial dimensions and the benefits of using surface mounted optoelectronic as well as electronic chips. We present three different types of packet-based switch fabrics, all based on the optical planar interconnection technology. We then discuss these in terms of capacity, scalability, and physical size. All three implementations have a single switch plane cross sectional bandwidth exceeding 5 Tbps.
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| 2. |
- Kruusmaa, Maarja
(författare)
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Global level path planning for mobile robots in dynamic environments
- 2003
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Ingår i: Journal of Intelligent and Robotic Systems. - Dordrecht : Kluwer Academic Publishers. - 0921-0296 .- 1573-0409. ; 38:1, s. 55-83
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a self- adapting approach to global level path planning in dynamic environments. The aim of this work is to minimize risk and delays in possible applications of mobile robots ( e. g., in industrial processes). We introduce a hybrid system that uses case-based reasoning as well as grid-based maps for decision-making. Maps are used to suggest several alternative paths between specific start and goal point. The casebase stores these solutions and remembers their characteristics. Environment representation and casebase design are discussed. To solve the problem of exploration vs. exploitation, a decision-making strategy is proposed that is based on the irreversibility of decisions. Forgetting strategies are discussed and evaluated in the context of case-based maintenance. The adaptability of the system is evaluated in a domain based on real sensor data with simulated occupancy probabilities. Forgetting strategies and decision-making strategies are evaluated in simulated environments. Experiments show that a robot is able to adapt in dynamic environments and can learn to use paths that are less risky to follow.
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| 3. |
- Malmberg, Donald
(författare)
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Innovative Contact Free Sensors for Metallurgical Process Control
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The steel- and metal industry has an extensive production processing comprising many different process steps of solid, gaseous and liquid nature. Thus it is obvious that a number of different measurement technologies must be used to collect and evaluate key physical parameters which are necessary to control the production processes. In this respect, the software to monitor the processes have, during the past decade, undergone extensive improvement whilst the sensors reading off the instantaneous process status have not and are still afflicted with severe drawbacks.This situation, in combination with increased demands on energy savings and rules regarding reduction of green house gas emission (the Kyoto protocol), has created incentives for the development and implementation of new technologies to monitor and control production processes in the steel and metal industry.The objectives in this thesis are to develop and evaluate sensor technology that can be used for in-situ on line analysis of metallurgical processes.The work is divided into:- To test and evaluate microwave technology for on line slag analysis.- To design, develop and evaluate microwave sensors for off gas analysis.- To evaluate laser sensors for simultaneous analysis of the process environment in metallurgical processes with emphasis on measuring the oxygen concentration and temperature in a steel reheating furnaceDuring the work on slag a broad band antenna was used for the microwave investigations on solid and liquid slag. The results show that it is possible to evaluate a refractive index for both solid and liquid slag. The results also show that there is a weak correlation between the refractive index for liquid slag and slag basicity.Trials on off gases from a pilot process as well as a full scale metallurgical production processes have been performed with microwave technology. The instrument used for the microwave trials has been developed from individual components. The results show that it is possible to use the technology for process analysis however the data collected regarding individual spectral lines still remain to be correlated to known molecular frequencies.Laser technology for gas analysis is a known technology in many different industrial applications. However, using the technology in steel and metal production processes requires that the technology must be adapted to the environment specific to those processes. Trials on a pilot process has been performed to find a suitable set of O2 absorption line parameters to be used during the forthcoming trials of full scale production processes. The outcome of these trials clearly show that the TDLAS technology can be used successfully on reheating furnaces but have a limited application potential on the LD converter process as well as the EAF.The benefit of the presented work will on production scale contribute to a lowered emission of green house gases, lowered energy consumption and an improved production yield.
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| 4. |
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| 5. |
- Franke, Axel, et al.
(författare)
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The effect of in-cylinder gas flow on the interpretation of the ionization sensor signal
- 2003
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Ingår i: SAE Technical Papers. - Warrendale : S A E Inc..
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Konferensbidrag (refereegranskat)abstract
- The location of the peak pressure can serve as a control parameter to adjust ignition timing and optimize engine performance. The ionization sensor, an electrical probe for combustion diagnostics, can provide information about the peak pressure location. However, the reliability of such information is rather poor. In-cylinder gas flow at the electrodes may be one reason for this. We present results from an investigation of the relationship between ionization sensor current and pressure under various gas flow conditions. The gas flow velocity in the vicinity of the electrode gap was measured by LDA. From the results one may infer how the in-cylinder gas flow affects the reliability of the prediction of pressure peak location from the ionization sensor signal. One finding is that high bulk gas flow impairs the precision of the prediction in certain configurations.
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| 6. |
- Uhlemann, Elisabeth, et al.
(författare)
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Optimal Incremental-redundancy strategy for type-II hybrid ARQ
- 2003
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Ingår i: ISIT 2003 Yokohama. - Piscataway, N.J. : IEEE. - 0780377281 ; , s. 448-, s. 448-
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Konferensbidrag (refereegranskat)abstract
- Given a type-II hybrid ARQ scheme, we propose a general solution to find the optimal partitioning of n-k parity bits over at most M transmissions. The solution is in terms of maximizing the average code rate for a given puncturing pattern.
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| 7. |
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| 8. |
- Baerveldt, Albert-Jan, et al.
(författare)
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Vision-guided mobile robots for design competitions
- 2003
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Ingår i: IEEE robotics & automation magazine. - : IEEE, The Institute of Electrical and Electronics Engineers. - 1070-9932 .- 1558-223X. ; 10:2, s. 38-44
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Tidskriftsartikel (refereegranskat)abstract
- The use of popular and effective robot-design competitions in teaching system integration in engineering curricula was discussed. Such robot competitions give students open-ended problem spaces, teaches them to work in groups and stimulates creativity. The technical and pedagogical aspects of robot competitions along with their experiences and shortcomings were also discussed.
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| 9. |
- Bigun, Josef, 1961-, et al.
(författare)
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Multimodal biometric authentication using quality signals in mobile communications
- 2003
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Ingår i: Proceedings - 12th International Conference on Image Analysis and Processing, ICIAP 2003. - Los Alamitos, USA : IEEE Computer Society. - 0769519482 ; , s. 2-11
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The elements of multimodal authentication along with system models are presented. These include the machine experts as well as machine supervisors. In particular fingerprint and speech based systems will serve as illustration of a mobile authentication application. A novel signal adaptive supervisor, based on the input biometric signal quality is evaluated. Experimental results on data collected from mobile telephones are reported demonstrating the benefits of the proposed scheme. © 2003 IEEE.
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| 10. |
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