| 1. |
- Verikas, Antanas, 1951-, et al.
(författare)
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Soft fusion of neural classifiers
- 1998
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Ingår i: ICONIP'98. - Burke, VA : IOS Press. - 4274902595 ; , s. 195-198
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Konferensbidrag (refereegranskat)abstract
- This paper presents three schemes for soft fusion of outputs of multiple neural classifiers. The weights assigned to classifiers or groups of them are data dependent. The first scheme performs linear combination of outputs of classifiers and, in fact, is the BADD defuzzification strategy. The second approach involves calculation of fuzzy integrals. The last scheme performs weighted averaging with data dependent weights. An empirical evaluation using widely accessible data sets substantiates the validity of the approaches with data dependent weights compared to various existing combination schemes of multiple classifiers. The majority rule, combination by averaging, the weighted averaging, the Borda count, and the fuzzy integral have been used for the comparison.
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| 2. |
- Zhang, Fu-Jung, et al.
(författare)
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Viewing angles in some selected BL Lac objects
- 1996
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Ingår i: Astrophysics and Space Science. - : Springer. - 0004-640X .- 1572-946X. ; 235:2, s. 195-205
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Tidskriftsartikel (refereegranskat)abstract
- A selected subset of BL Lac objects were monitored with VLBI techniques at multifrequencies. Apparent superlumJnal motion and X-rays were detected in all of the monitored sources. From the observational data, kinematic parameters, geometric parameters and beaming effects for the 'core' of the selected BL Lac objects have been estimated. Our results indicate that some BL Lacs have large Lorentz factors and small viewing angles; relativistic beaming effects are strongly present in these sources. On the other hand, some BL Lacs have small Lorentz thctors; their viewing angles are quite large. It does not seem possible to avoid the fact that some BL Lac objects are not oriented particularly close to the line of sight. It conflicts with the basic assumption of the accepted theories for explaining the characteristics of BL Lac objects at present. Also, it seems that the BL Lac objects in the class I of the Burdige and Hewitt's classification have larger viewing angles than those int he class II. The whole BL Lac classification could be a misnomer: the sources classified as 'BL Lac objects' are a mixture of physically different populations with different parent objects.
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| 3. |
- Jonsson, Magnus, 1969-
(författare)
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High performance fiber-optic interconnection networks for real-time computing systems
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Parallel and distributed computing systems become more and more powerful and hence place increasingly higher demands on the networks that interconnect their processors or processing nodes. Many of the applications running on such systems, especially embedded systems applications, have real-time requirements and, with increasing application demands, high-performance networks are the hearts of these systems. Fiber-optic networks are good candidates for use in such systems in the future. This thesis contributes to the relatively unexplored area of fiber-optic networks for parallel and distributed real-time computer systems and suggests and evaluates several fiber-optic networks and protocols. Two different technologies are used in the networks, WDM (Wavelength Division Multiplexing) and fiber-ribbon point-to-point links. WDM offers multiple channels, each with a capacity of several Gbit/s. A WDM star network in which protocols and services are efficiently integrated to support different kinds of real-time demands, especially hard ones, has been developed. The star-of-stars topology can be chosen to offer better network scalability. The WDM star architecture is attractive but its future success depends on components becoming more commercially mature. Fiber-ribbon links, offering instead an aggregated bandwidth of several Gbit/s, have already reached the market with a promising price/performance ratio. This has motivated the development and investigation of two new ring networks based on fiber-ribbon links. The networks take advantage of spatial bandwidth reuse, which can greatly enhance performance in applications with a significant amount of nearest downstream neighbor communication. One of the ring networks is control channel based and not only has support for real-time services like the WDM star network but also low level support for, e.g., group communication. The approach has been to develop network protocols with support for dynamic real-time services, out of time-deterministic static TDMA systems. The focus has been on functionality more than pure performance figures, mostly on real-time features but also on other types of functionality for parallel and distributed systems. Worst-case analyses, some simulations, and case studies are reported for the networks. The focus has been on embedded supercomputer applications, where each node itself can be a parallel computer, and it is shown that the networks are well suited for use in the radar signal processing systems studied. Other application examples in which these kinds of networks are valuable are distributed multimedia systems, satellite imaging and other image processing applications.
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| 4. |
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| 5. |
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| 6. |
- Bååth, Lars B., et al.
(författare)
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Imaging with Interferometers
- 1998
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Ingår i: Proceedings SSAB Symposium on Image Analysis. ; , s. 4-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A scanning device based on changes in the reflections of an electromagnetic wave for use on wood the image can be calculated.
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| 7. |
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| 8. |
- Chu, H.S., et al.
(författare)
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VLBI observations of the puzzling BL Lacertae object 0235+164
- 1996
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Ingår i: Astronomy and Astrophysics. - : Springer. - 0004-6361 .- 1432-0746. ; 307:1, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- For over 20 years, many models have been proposed to explain the variability of AO0235+164. Among them, the most favorable has been micro-lensing. We have made a series of VLBI observations on this source in order to better understand its nature. The resultant maps indicate dramatic changes in the position angle of the jet between observations as well as a correlation between the intensity of the VLBI core and flux outbursts which occurred between the observing sessions. These characteristics, in conjunction with other arguments, suggest that the source variability is intrinsic, i.e. microlensing is of minor importance. We suggest two models: 1) a model in which the jet starts at a very small angle to the line of sight and then curves away to become about 6deg at about 1 mas from the core; and 2) a CME (Coronal Mass Ejection) model that also may explain the violent variability in intensity, polarization position angle, and jet direction in AO0235+164.
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| 9. |
- Duc, Benoıt, et al.
(författare)
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Face authentication with Gabor information on deformable graphs
- 1999
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Ingår i: IEEE Transactions on Image Processing. - New York, NY : IEEE Press. - 1057-7149 .- 1941-0042. ; 8:4, s. 504-516
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Tidskriftsartikel (refereegranskat)abstract
- Elastic graph matching has been proposed as a practical implementation of dynamic link matching, which is a neural network with dynamically evolving links between a reference model and an input image. Each node of the graph contains features that characterize the neighborhood of its location in the image. The elastic graph matching usually consists of two consecutive steps, namely a matching with a rigid grid, followed by a deformation of the grid, which is actually the elastic part. The deformation step is introduced in order to allow for some deformation, rotation, and scaling of the object to be matched. This method is applied here to the authentication of human faces where candidates claim an identity that is to be checked. The matching error as originally suggested is not powerful enough to provide satisfying results in this case. We introduce an automatic weighting of the nodes according to their significance. We also explore the significance of the elastic deformation for an application of face-based person authentication. We compare performance results obtained with and without the second matching step. Results show that the deformation step slightly increases the performance, but has lower influence than the weighting of the nodes. The best results are obtained with the combination of both aspects. The results provided by the proposed method compare favorably with two methods that require a prior geometric face normalization, namely the synergetic and eigenface approaches
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| 10. |
- Fridlund, Bengt
(författare)
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The case study as a research strategy
- 1997
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Ingår i: Scandinavian Journal of Caring Sciences. - Oxford : Blackwell Publishing. - 0283-9318 .- 1471-6712. ; 11:1, s. 3-4
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Tidskriftsartikel (refereegranskat)abstract
- A research strategy seldom used in the caring sciences is the case study. A case study is an empirical in-depth inquiry about an individual, family, group or organization. It is preferable when 'how' and 'why' questions are asked. The case study is mainly used to explain those causal links in real-life intervention that are too complex for either the survey or experimental strategies. Like other research strategies, its design includes questions or propositions, units of analysis, the logic linking the data to the questions or propositions, and the interpretations of the outcomes. A case study can be reported as a single case or as a compilation of a series of cases. In conclusion a case study is a simple and excellent way for a care professional to present him or herself to the scientific world.
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