| 21. |
- Bigun, Josef, et al.
(författare)
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Assuring liveness in biometric identity authentication by real-time face tracking
- 2004
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Ingår i: CIHSPS 2004. - Piscataway, N.J. : IEEE Press. - 0780383818 - 9780780383814 ; , s. 104-111
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Konferensbidrag (refereegranskat)abstract
- A system that combines real-time face tracking as well as the localization of facial landmarks in order to improve the authenticity of fingerprint recognition is introduced. The intended purpose of this application is to assist in securing public areas and individuals, in addition to enforce that the collected sensor data in a multi modal person authentication system originate front present persons, i.e. the system is not under a so called play back attack. Facial features are extracted with the help of Gabor filters and classified by SVM experts. For real-time performance, selected points from a retinotopic grid are used to form regional face models. Additionally only a subset of the Gabor decomposition is used for different face regions. The second modality presented is texture-based fingerprint recognition, exploiting linear symmetry. Experimental results on the proposed system are presented.
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| 22. |
- Bigun, Josef, 1961-, et al.
(författare)
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Recognition by symmetry derivatives and the generalized structure tensor
- 2004
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Ingår i: IEEE Transactions on Pattern Analysis and Machine Intelligence. - Los Alamitos, USA : IEEE Computer Society. - 0162-8828 .- 1939-3539. ; 26:12, s. 1590-1605
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Tidskriftsartikel (refereegranskat)abstract
- We suggest a set of complex differential operators that can be used to produce and filter dense orientation (tensor) fields for feature extraction, matching, and pattern recognition. We present results on the invariance properties of these operators, that we call symmetry derivatives. These show that, in contrast to ordinary derivatives, all orders of symmetry derivatives of Gaussians yield a remarkable invariance: they are obtained by replacing the original differential polynomial with the same polynomial, but using ordinary coordinates x and y corresponding to partial derivatives. Moreover, the symmetry derivatives of Gaussians are closed under the convolution operator and they are invariant to the Fourier transform. The equivalent of the structure tensor, representing and extracting orientations of curve patterns, had previously been shown to hold in harmonic coordinates in a nearly identical manner. As a result, positions, orientations, and certainties of intricate patterns, e.g., spirals, crosses, parabolic shapes, can be modeled by use of symmetry derivatives of Gaussians with greater analytical precision as well as computational efficiency. Since Gaussians and their derivatives are utilized extensively in image processing, the revealed properties have practical consequences for local orientation based feature extraction. The usefulness of these results is demonstrated by two applications:tracking cross markers in long image sequences from vehicle crash tests andalignment of noisy fingerprints.
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| 23. |
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| 24. |
- Bilstrup, Urban, et al.
(författare)
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A fault tolerance test enabling QoS in a Bluetooth piconet
- 2004
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Konferensbidrag (populärvet., debatt m.m.)abstract
- An important trend, in personal area networks, is that time critical application becomes more common, e.g., voice over IP, video phone calls, network games. This segment of applications demands for quality of service (QoS) guarantees, to provide the correct functionality. The Bluetooth standard provides an optional interface to support QoS guarantees, but the standard does not suggest any actual implementation. A wireless communication channel is stochastic by nature, providing QoS guarantees with this precondition make traditional deterministic real-time theory obsolete. In this paper a probabilistic fault tolerance test enabling quality of service guarantees in a Bluetooth piconet is given. The basic Bluetooth network architecture is based on a master-slave configuration, i.e., a point to point connection. More advanced network architectures are possible where up to eight Bluetooth equipped units can be active members of one network (piconet). Furthermore, several piconets can interconnect and form a so called scatternet.
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| 25. |
- Bilstrup, Urban, et al.
(författare)
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An architecture comparison between a wireless sensor network and an active RFID system
- 2004
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Ingår i: The 29th Annual IEEE International Conference on Local Computer Networks, 2004. - : IEEE. - 0769522602 ; , s. 583-584
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Konferensbidrag (refereegranskat)abstract
- In This work a new hardware platform for active RFID and wireless sensor network is presented. Furthermore a comparison of these two architectures is performed, i.e., the singlehop and the multihop architecture. The comparison reveals important issues regarding the utilization and energy consumption for the singlehop as well as for the multihop architecture.
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| 26. |
- Björk, Eva-Stina
(författare)
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Insider Action Research (IAR) of product development processes
- 2004
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Ingår i: TOOLS AND METHODS OF COMPETITIVE ENGINEERING Vols 1 and 2. - Rotterdam : Millpress Science Publishers. ; , s. 1043-1052
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Konferensbidrag (refereegranskat)abstract
- Performing product development means to simultaneously develop product systems, production processes and marketing efforts. Product Development processes are often complex as they are time dependent and contain many inter-dependencies e.g. between parts and individuals involved Due to the complexity in these processes the methods for research on integrated product development processes need to be designed differently than traditional research methods used. The study of details of totalities can work for mechanical systems but less well for complex systems. For a deeper knowledge of complex systems substantial researcher involvement and participation in real time is essential, which Insider Action Research (IAR) is designed for. IAR can be performed from the three main positions as observer, team member or project leader. The-following conclusions have been drawn (Bjork 2003): The IAR approach is beneficial in most types of development processes and projects when the aim of the research is to achieve increased knowledge and understanding. A mix of detailed and narrative descriptions of a research project provides also practitioners with an opportunity to adopt the findings. The implementation of research results would thereby become facilitated, which is an effect that most researchers as well as practitioners would benefit from.
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| 27. |
- Blomgren, Bo, et al.
(författare)
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A computerised, unbiased method for epithelial measurement
- 2004
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Ingår i: Micron. - Amsterdam : Elsevier. - 0968-4328 .- 1878-4291. ; 35, s. 319-329
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo develop and evaluate a standardised method for unbiased measurements of epithelial thickness taking the variability of the dermal papillae in consideration.MethodsA computer-assisted measurement program suitable for haematoxylin and eosin routine stained specimens has been developed.ResultsThe developed program was designed to measure four different distance parameters, taking the number, height and width of dermal papillae into account. The measurement program gave very accurate results compared with manual measurements. The measurement results can be presented as tables or star graphs, and the results can be further processed by multivariate analysis.ConclusionThe computer-assisted measurement program is considered to be a valuable and reliable tool for measurements of epithelial thickness, irrespectively of the variability of the epithelial morphology. Since length, size and number of the papillae may change with certain pathological conditions, age and also under hormonal influence, this method can be a helpful diagnostic tool.
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| 28. |
- Blomkvist, Marita, 1959-
(författare)
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Entreprenörers delaktighet i att producera redovisning
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Entrepreneurs seem to be highly valuable for the firms in which they are involved. However, the knowledge of the role of accounting in a context of entrepreneurship is almost non-existent. Infact, literature in entrepreneurship says that the role of accounting is only about the past and therefore not of interest for the entrepreneur in exploiting opportunities. This paper reports the result of a qualitative study of five entrepreneurs and their involvement in the process of financial reporting. The study aimed to describe and analyse if and how entrepreneurs are involved in producing accounting information when the annual report were prepared. If the entrepreneurs were involved, the purpose was also to explain why the entrepreneurs were involved in the process. In purpose to find entrepreneurs the owner-managers of five small growing companies were asked to participate in semi-structured interviews during which their involvement to produce accounting where discussed. The respondents were also presented the adjustments, the final step in the recording process, and the annual report, in order to assess their involvement and to focus on how the entrepreneurs as producers of annual reports reflect and act in relation to other actors and to the process on the reporting. The study found that the entrepreneurs were certainly involved in producing the annual report. The analysis reveals that the reports were carefully fabricated and consciously managed by the entrepreneurs in the study. The entrepreneurs where involved in the process when certain values of the assets were established and they wrote the directors annual report. The study concludes that it appears to be important for entrepreneurs in small growing firms to discuss and produce accounting together with other actors, primarily the accountant, to improve their understanding and to identify how the audience of the annual reports may read and interpret the annual reports.
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| 29. |
- Bodén, Mikael
(författare)
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Generalization by symbolic abstraction in cascaded recurrent networks
- 2004
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Ingår i: Neurocomputing. - : Elsevier. - 0925-2312 .- 1872-8286. ; 57:1-4, s. 87-104
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Tidskriftsartikel (refereegranskat)abstract
- Generalization performance in recurrent neural networks is enhanced by cascading several networks. By discretizing abstractions induced in one network, other networks can operate on a coarse symbolic level with increased performance on sparse and structural prediction tasks. The level of systematicity exhibited by the cascade of recurrent networks is assessed on the basis of three language domains.
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| 30. |
- Bohm-Starke, Nina, et al.
(författare)
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Decreased mechanical pain threshold in the vestibular mucosa of women using oral contraceptives : a contributing factor in vulvar vestibulitis?
- 2004
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Ingår i: Journal of reproductive medicine. - Chicago : The Journal. - 0024-7758 .- 1943-3565. ; 49:11, s. 888-892
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Tidskriftsartikel (refereegranskat)abstract
- Objective:To analyze possible differences in somatosensory perception in the vestibular mucosa in healthy women associated with the use of oral contraceptives.Study design:Quantitative sensory tests were performed on the vestibular mucosa in 39 healthy women. Twenty women were using oral contraceptives containing 30-40 µg ethinyl estradiol combined with various progestins; 19 women with regular menstrual periods not using oral contraceptives served as controls. The testing included mechanical and heat pain thresholds and detection thresholds of warmth and cold in the anterior and posterior part of the vestibule.Results:Significant lower mechanical pain thresholds were observed in both areas tested in women using oral contraceptives. The most sensitive area was the posterior vestibule in the group using oral contraceptives with a mechanical pain threshold of 72±10 (±SEM) mN as compared to 161±3 mN (p<0.01), in the controls. The result of the thermotest showed no significant differences between the groups.Conclusion:Oral contraceptives may induce increased sensitivity in the vestibular mucosa in healthy women and might be one contributing factor in the development of vulvar vestibulitis.
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