2004
Autores
Rodrigues, R; Fernandes, A; van Overveld, K; Ernst, F;
Publicação
IMAGE AND VISION COMPUTING
Abstract
We present a novel approach for 3D reconstruction based on a set of images taken from a static scene. Our solution is inspired by the spatiotemporal analysis of video sequences. The method is based on a best fitting scheme for spatiotemporal curves that allows us to compute 3D world coordinates of points within the scene. As opposed to a large number of current methods, our technique deals with random camera movements in a transparent way, and even performs better in these cases than with restrained motion such as pure translation. Robustness against occlusion and aliasing is inherent to the method as well.
2004
Autores
Portugal, PJ; Carvalho, AD;
Publicação
2004 IEEE International Conference on Industrial Technology (ICIT), Vols. 1- 3
Abstract
The paper presents a framework to evaluate dependability of PROFIBUS-DP networks. An hierarchical modeling approach is proposed, which considers both the effects of different kinds of faults - permanent, transient and common-cause square and the interaction between hardware and software components. Stochastic Petri Nets are used as the modeling technique to obtain dependability models, with emphasis in the use of analytical/numerical methods to provide model's solutions. In scenarios where its difficult to apply this approach, compact simulation models are derived.
2004
Autores
Li, ZJ; Soares, I; Fernandes, JM; Cunha, JPS;
Publicação
INTERNATIONAL JOURNAL OF PSYCHOPHYSIOLOGY
Abstract
2004
Autores
Portugal, PJ; Carvalho, AD;
Publicação
WFCS 2004: IEEE INTERNATIONAL WORKSHOP ON FACTORY COMMUNICATION SYSTEMS, PROCEEDINGS
Abstract
The paper presents a framework to evaluate dependability of fieldbus networks. An hierarchical modeling approach is proposed, which considers both the effects of different kinds of faults - permanent, transient and common-cause - and the interaction between hardware and software components. Stochastic Petri Nets are used as the modeling technique to obtain dependability models, with emphasis in the use of analytical/numerical methods to provide model's solutions.
2004
Autores
Wagner, P; Cunha, J; Mauerer, C; Vollmar, C; Feddersen, B; Noachtar, S;
Publicação
EPILEPSIA
Abstract
2004
Autores
Rosa, CC; Podoleanu, AG;
Publicação
APPLIED OPTICS
Abstract
Owing to the limited spectral response of the fiber directional coupler used in a balanced optical coherence tomography configuration, the spectra are different in the two outputs. This affects unfavorably operation of the balanced photodetector unit. Excess photon noise makes a larger contribution than a directional coupler with a flat spectral response. A theoretical model is developed that shows that an optimum set of parameters may be defined to maximize the achievable signal-to-noise ratio. The model leads to a redefinition of the effective noise bandwidth, which takes into account the nonflat response of the directional coupler used. The model also predicts a limitation on the signal-to-noise ratio even when the stray reflectances in the interferometer are brought to zero. (C) 2004 Optical Society of America.
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