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61.
Aguzzoli Stefano; Busaniche Manuela; Marra Vincenzo 《Journal of Logic and Computation》2007,17(4):749-765
We establish a categorical duality for the finitely generatedLindenbaum-Tarski algebras of propositional nilpotent minimumlogic. The latter's conjunction is semantically interpretedby a left-continuous (but not continuous) triangular norm; implicationis obtained through residuation. Our duality allows one to transferto nilpotent minimum logic several known results about inutitionisticlogic with the prelinearity axiom (also called Gödel-Dummettlogic), mutatis mutandis. We give several such applications. 相似文献
62.
63.
Algorithmic and architectural design for real-time and power-efficient Retinex image/video processing 总被引:1,自引:1,他引:0
Sergio Saponara Luca Fanucci Stefano Marsi Giovanni Ramponi 《Journal of Real-Time Image Processing》2007,1(4):267-283
This paper presents novel algorithmic and architectural solutions for real-time and power-efficient enhancement of images
and video sequences. A programmable class of Retinex-like filters, based on the separation of the illumination and reflectance
components, is proposed. The dynamic range of the input image is controlled by applying a suitable non-linear function to
the illumination, while the details are enhanced by processing the reflectance. An innovative spatially recursive rational
filter is used to estimate the illumination. Moreover, to improve the visual quality results of two-branch Retinex operators
when applied to videos, a novel three-branch technique is proposed which exploits both spatial and temporal filtering. Real-time
implementation is obtained by designing an Application Specific Instruction-set Processor (ASIP). Optimizations are addressed
at algorithmic and architectural levels. The former involves arithmetic accuracy definition and linearization of non-linear
operators; the latter includes customized instruction set, dedicated memory structure, adapted pipeline, bypasses, custom
address generator, and special looping structures. The ASIP is synthesized in standard-cells CMOS technology and its performances
are compared to known Digital signal processor (DSP) implementations of real-time Retinex filters. As a result of the comparison,
the proposed algorithmic/architectural design outperforms state-of-art Retinex-like operators achieving the best trade-off
between power consumption, flexibility, and visual quality.
Sergio Saponara is a Research Scientist and Assistant Professor at the University of Pisa. He was born in Bari, Italy, in 1975. He received the Electronic Engineering degree cum laude and the Ph.D. in Information Engineering, both from Pisa University, in 1999 and 2003, respectively. Since 2001 he collaborates with Consorzio Pisa Ricerche, Italy and in 2002 he was with IMEC, Belgium as Marie Curie research fellow. His research and teaching interests include electronic circuits and systems for multimedia, telecom and automation. He co-authored more than 40 papers including journals, conferences and patents. Luca Fanucci is Associate Professor of Microelectronics at the University of Pisa. He was born in Montecatini, Italy, in 1965. He received the Doctor Engineer degree and the Ph.D. in Electronic Engineering from the University of Pisa in 1992 and 1996, respectively. From 1992 to 1996, he was with the European Space Agency's Research and Technology Center, Noordwijk, The Netherlands, and from 1996 to 2004 he was a Research Scientist of the Italian National Research Council in Pisa. His research interests include design technologies for integrated circuits and systems, with emphasis on system-level design, hardware/software co-design and low-power. He co-authored more than 100 journal/conference papers and holds more than 10 patents. Stefano Marsi was born in Trieste, Italy, in 1963. He received the Doctor Engineer degree in Electronic Engineering (summa cum laude) in 1990 and the Ph.D. degree in 1994. Since 1995 he has held the position of researcher in the Department of Electronics at the University of Trieste where he is the teacher of courses in electronic field. His research interests include non-linear operators for image and video processing and their realization through application specific electronics circuits. He is author or co-author of more than 40 papers in international journals, proceedings of international conferences or contributions in books. Giovanni Ramponi is Professor of Electronics at the Department of Electronics of the University of Trieste, Italy. His research interests include nonlinear digital signal processing, and the enhancement and feature extraction in images and image sequences. Prof. Ramponi has been an Associate Editor of the IEEE Signal Processing Letters and of the IEEE Transactions on Image Processing; presently is an AE of the SPIE Journal of Electronic Imaging. He has participated in various EU and National Research Projects. He is the co-inventor of various pending international patents and has published more than 140 papers in international journals and conference proceedings, and as book chapters. Prof. Ramponi contributes to several undergraduate and graduate courses on digital signal processing. 相似文献
Giovanni RamponiEmail: |
Sergio Saponara is a Research Scientist and Assistant Professor at the University of Pisa. He was born in Bari, Italy, in 1975. He received the Electronic Engineering degree cum laude and the Ph.D. in Information Engineering, both from Pisa University, in 1999 and 2003, respectively. Since 2001 he collaborates with Consorzio Pisa Ricerche, Italy and in 2002 he was with IMEC, Belgium as Marie Curie research fellow. His research and teaching interests include electronic circuits and systems for multimedia, telecom and automation. He co-authored more than 40 papers including journals, conferences and patents. Luca Fanucci is Associate Professor of Microelectronics at the University of Pisa. He was born in Montecatini, Italy, in 1965. He received the Doctor Engineer degree and the Ph.D. in Electronic Engineering from the University of Pisa in 1992 and 1996, respectively. From 1992 to 1996, he was with the European Space Agency's Research and Technology Center, Noordwijk, The Netherlands, and from 1996 to 2004 he was a Research Scientist of the Italian National Research Council in Pisa. His research interests include design technologies for integrated circuits and systems, with emphasis on system-level design, hardware/software co-design and low-power. He co-authored more than 100 journal/conference papers and holds more than 10 patents. Stefano Marsi was born in Trieste, Italy, in 1963. He received the Doctor Engineer degree in Electronic Engineering (summa cum laude) in 1990 and the Ph.D. degree in 1994. Since 1995 he has held the position of researcher in the Department of Electronics at the University of Trieste where he is the teacher of courses in electronic field. His research interests include non-linear operators for image and video processing and their realization through application specific electronics circuits. He is author or co-author of more than 40 papers in international journals, proceedings of international conferences or contributions in books. Giovanni Ramponi is Professor of Electronics at the Department of Electronics of the University of Trieste, Italy. His research interests include nonlinear digital signal processing, and the enhancement and feature extraction in images and image sequences. Prof. Ramponi has been an Associate Editor of the IEEE Signal Processing Letters and of the IEEE Transactions on Image Processing; presently is an AE of the SPIE Journal of Electronic Imaging. He has participated in various EU and National Research Projects. He is the co-inventor of various pending international patents and has published more than 140 papers in international journals and conference proceedings, and as book chapters. Prof. Ramponi contributes to several undergraduate and graduate courses on digital signal processing. 相似文献
64.
Costanzi S Vincenzetti S Cristalli G Vita A 《Journal of molecular graphics & modelling》2006,25(1):10-16
Cytidine deaminase (CDA) is a cytosolic metalloprotein whose functional unit can be either a homotetramer (T-CDA) or a homodimer (D-CDA), depending on the species. In 1994, the first crystal structure of the dimeric Escherichia coli CDA has been published. However, a crystal structure of a tetrameric CDA was not determined until 2002. Prior to the disclosure of the experimentally elucidated structure of a tetrameric CDA, we derived a homology model of the human T-CDA employing the crystal structure of the dimeric E. coli CDA as a template. The comparison of our theoretical model with the crystal structure of the human T-CDA, subsequently published in 2004, validates our prediction: not only of the structural features of the monomer and the details of the binding site, but also the multimeric arrangement of the subunits were determined with high accuracy in our model. By means of a phylogenetic analysis conducted on CDAs from various organisms, we demonstrate that the E. coli CDA is one of the furthest known homologues of the human enzyme. Nonetheless, despite the evolutionary distance and, more importantly, the different multimeric arrangement of their functional units, the E. coli CDA proved to have all the necessary information to accurately infer the structure of its human homologue. 相似文献
65.
66.
We consider devices equipped with multiple wired or wireless interfaces. By switching of various interfaces, each device might establish several connections. A connection is established when the devices at its endpoints share at least one active interface. Each interface is assumed to require an activation cost. In this paper, we consider two basic networking problems in the field of multi-interface networks. The first one, known as the Coverage problem, requires to establish the connections defined by a network. The second one, known as Connectivity problem, requires to guarantee a connecting path between any pair of nodes of a network. Both are subject to the constraint of keeping as low as possible the maximum cost set of active interfaces at each single node. We study the problems of minimizing the maximum cost set of active interfaces among the nodes of the network in order to cover all the edges in the first case, or to ensure connectivity in the second case. We prove that the Coverage problem is NP-hard for any fixed Δ≥5 and k≥16, with Δ being the maximum degree, and k being the number of different interfaces among the network. We also show that, unless P=NP, the problem cannot be approximated within a factor of ηln?Δ, for a certain constant η. We then provide a general approximation algorithm which guarantees a factor of O((1+b)ln?Δ), with b being a parameter depending on the topology of the input graph. Interestingly, b can be bounded by a constant for many graph classes. Other approximation and exact algorithms for special cases are presented. Concerning the Connectivity problem, we prove that it is NP-hard for any fixed Δ≥3 and k≥10. Also for this problem, the inapproximability result holds, that is, unless P=NP, the problem cannot be approximated within a factor of ηln?Δ, for a certain constant η. We then provide approximation and exact algorithms for the general problem and for special cases, respectively. 相似文献
67.
A separation result for some kind of global stabilization via output feedback of a class of nonlinear systems, under the form of some stabilizability by state feedback on the one hand, and some unboundedness observability on the other hand is presented. They allow to design, for any domain of output initial condition, some dynamic output feedback controller achieving global stability. It is also highlighted how disturbance attenuation can further be achieved on the same basis. As an example, the proposed conditions are shown to be satisfied by the class of so-called Euler-Lagrange systems, for which a tracking output feedback control law is thus proposed. 相似文献
68.
Nicola Mazzocca Stefano Russo Valeria VittoriniAuthor vitae 《Journal of Systems Architecture》1997,43(10):671-685
This paper describes a real-world case study in the specification and analysis of dependable distributed systems. The case study is an automated transport system with safety requirements. In order to manage the complexity of the problem of specifying the dynamic behavior of the whole system, a compositional approach is used, based on the integration of the trace logic of the Communicating Sequential Processes (CSP) theory, and stochastic Petri nets (SPNs). It is argued that the integration of different formal methods is a useful approach in the definition of practical engineering methodologies for the specification, design and analysis of complex dependable distributed systems. 相似文献
69.
Fabio Ancona Stefano Rovetta Rodolfo Zunino 《Engineering Applications of Artificial Intelligence》1997,10(6):573-580
The paper describes a parallel implementation of a neural algorithm performing vector quantization for very low bit-rate video compression on toroidal-mesh multiprocessor systems. The neural model considered is a plastic version of the Neural Gas algorithm, whose features are suitable for implementations on toroidal mesh topologies. The architecture adopted, and the data-allocation strategy, enhance the method's scaling properties and remarkable efficiency. The parallel approach is supported by a theoretical analysis of the efficiency of the overall structure. Experimental results on a significant testbed and the fit between predicted and measured values confirm the validity of the parallel approach. 相似文献
70.
Berretti Stefano Del Bimbo Alberto Pala Pietro 《Multimedia Tools and Applications》2004,24(3):215-232
Searching information through the Internet often requires users to separately contact several digital libraries, use each library interface to author the query, analyze retrieval results and merge them with results returned by other libraries. Such a solution could be simplified by using a centralized server that acts as a gateway between the user and several distributed repositories: The centralized server receives the user query, forwards the user query to federated repositories—possibly translating the query in the specific format required by each repository—and fuses retrieved documents for presentation to the user. To accomplish these tasks efficiently, the centralized server should perform some major operations such as: resource selection, query transformation and data fusion.
In this paper we report on some aspects of MIND, a system for managing distributed, heterogeneous multimedia libraries (MIND, 2001, http://www.mind-project.org). In particular, this paper focusses on the issue of fusing results returned by different image repositories. The proposed approach is based on normalization of matching scores assigned to retrieved images by individual libraries. Experimental results on a prototype system show the potential of the proposed approach with respect to traditional solutions. 相似文献