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347 results on '"Rovatti, R"'

2. Markov Modeling of Cooperative Multiplayer Coupon Collectors' Problems

Author

Rovatti, R., Passerini, C., and Mazzini, G.

Subjects
Computer Science - Discrete Mathematics
Abstract

The paper introduces a modified version of the classical Coupon Collector's Problem entailing exchanges and cooperation between multiple players. Results of the development show that, within a proper Markov framework, the complexity of the Cooperative Multiplayer Coupon Collectors' Problem can be attacked with an eye to the modeling of resource harvesting and sharing within the context of Next Generation Network. The cost of cooperation is computed in terms of exchange protocol burden and found to be dependent on only ensemble parameters such as the number of players and the number of coupons but not on the detailed collection statistics. The benefits of cooperation are quantified in terms of reduction of the average number of actions before collection completion., Comment: 14 pages, 5 figures

Published
2009

6. Compressed Sensing Inspired Neural Decoder for Undersampled MRI with Self-Assessment

Author

Martinini, F., Mangia, M., Pareschi, F., Rovatti, R., Setti, G., Martinini, Filippo, Mangia, Mauro, Pareschi, Fabio, Rovatti, Riccardo, and Setti, Gianluca

Subjects
Magnetic resonance imaging, Measurement uncertainty, Decoding, Image reconstruction, Magnetic Resonance Imaging (MRI), Compressed Sensing (CS), Neural Networks, Deep Neural Networks, U-NET, Time measurement, Magnetic resonance imaging, Measurement uncertainty, Biomedical measurement, Time measurement, Robustness, Decoding, Image reconstruction, Biomedical measurement, Robustness
Published
2021

8. On the approximate solution of a class of large discrete quadratic programming problems by \delta \sigma modulation: the case of circulant quadratic forms

Author

Callegari, S., Bizzarri, F., Rovatti, R., and Setti, G.

Subjects
Quadratic programming -- Usage, Mathematical optimization -- Technology application, Signal processing -- Innovations, Electronic circuits -- Design and construction, Heuristic programming -- Usage, Frequency modulation -- Analysis, Digital signal processor, Technology application, Business, Computers, Electronics, Electronics and electrical industries
Published
2010

13. Compressed Sensing of ΔΣ Streams

Author

Callegari, S., Mangia, M., Rovatti, R., Setti, G., Sergio Callegari, Mauro Mangia, Riccardo Rovatti, and Gianluca Setti

Subjects
Compressed sensing, Delta-Sigma modulator, Delta-Sigma modulator, ECG, Compressed sensing
Abstract

Compressed sensing (CS) is often applied at the digital level. We consider the case where CS follows a ΔΣ data converter and we show that CS can be practiced directly on the ΔΣ stream. In the proposed scheme, an appropriate sensing matrix incorporates the ability to get rid of the quantization noise from the ΔΣ modulator. We also show that a suitable sparsity basis enables the CS information recovery to be practiced directly at the Nyquist rate and that decimation, which is typically inherent in ΔΣ data acquisition, is not needed. Furthermore, the low depth of ΔΣ streams allows CS measures to be taken without multipliers, streamlining arithmetic blocks. A test case based on electrocardiograms is used to validate the approach.

Published
2019

14. Automatic synthesis of analog fuzzy controllers: a hardware and software approach

Author

Manaresi, N., Rovatti, R., Franchi, E., Guerrieri, R., and Baccarani, G.

Subjects
Fuzzy systems -- Research, Electric controllers -- Research, Analog integrated circuits -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

In applications where low cost is the primary concern, analog VLSI controllers are an option. In this paper a hardware and software integrated toolkit for development of analog controllers based on fuzzy logic is presented. The system is composed of a CMOS analog circuit whose input/output relationship can be programmed to synthesize various control functions. The value of the programmable parameters can be automatically computed by the software tool, assuming that the user specifies the controller expected behavior by means of linguistic and/or numeric information. A complete example of how fuzzy linguistic and numerical methodologies can be combined with more conventional techniques to synthesize a nontrivial controller is detailed down to measured data. A final discussion clarifies the main advantages of the fuzzy analog computation when it is supported with an appropriate software layer: nontrivial solutions to problems in which accuracy is not the primary concern can be easily synthesized and integrated into very small silicon areas with small power requirements.

Published
1996

15. Digital approaches

Author

Umano, Motohide, primary, Baldwin, J, additional, Martin, T, additional, Pilsworth, B, additional, Petry, Frederick, additional, Jani, Yashvant, additional, Lea, Robert, additional, von Altrock, Constantin, additional, Rovatti, R, additional, Manaresi, N, additional, Franchi, E, additional, and Pagni, Andrea, additional

Published
1998
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16. Analog fuzzy implementation of a perceptual classifier for videophone sequences

Author

Bellini, A., Leone, A., Rovatti, R., Franchi, E., and Manaresi, N.

Subjects
Image coding -- Methods, Fuzzy systems -- Usage, Video telephones -- Design and construction, Business, Electronics and electrical industries, Engineering and manufacturing industries
Abstract

In this paper we describe the implementation of a perceptual classifier for image coding. A fully-programmable analog fuzzy circuit is used to compute the relevance coefficient for each block of a single frame in order to maximize the quality of the image according to a perceptive model of the human visual system. The application of the proposed system to a generic H.261 coder is discussed.

Published
1996

17. On the security of a class of diffusion mechanisms for image encryption

Author

Zhang, LY, Liu, Y, Pareschi, F, Zhang, Y, Wong, KW, Rovatti, R, Setti, G, Zhang, LY, Liu, Y, Pareschi, F, Zhang, Y, Wong, KW, Rovatti, R, and Setti, G

Abstract

© 2017 IEEE. The need for fast and strong image cryptosystems motivates researchers to develop new techniques to apply traditional cryptographic primitives in order to exploit the intrinsic features of digital images. One of the most popular and mature technique is the use of complex dynamic phenomena, including chaotic orbits and quantum walks, to generate the required key stream. In this paper, under the assumption of plaintext attacks we investigate the security of a classic diffusion mechanism (and of its variants) used as the core cryptographic primitive in some image cryptosystems based on the aforementioned complex dynamic phenomena. We have theoretically found that regardless of the key schedule process, the data complexity for recovering each element of the equivalent secret key from these diffusion mechanisms is only O(1). The proposed analysis is validated by means of numerical examples. Some additional cryptographic applications of this paper are also discussed.

Published
2018

24. A UWB CMOS 0.13μm low-noise amplifier with dual loop negative feedback

Author

De Michele, L., Serdijn, W. A., Bagga, S., Setti, Gianluca, Rovatti, R., De Michele, Luca Antonio, Serdijn, Wouter A., Bagga, Sumit, Setti, Gianluca, and Rovatti, Riccardo

Subjects
Electronic, Optical and Magnetic Material, Hardware_INTEGRATEDCIRCUITS, Electrical and Electronic Engineering
Abstract

A Low-Noise Amplifier for ultra wide band (UWB) applications is presented. The use of a dual-loop negative feedback topology is advantageous, since it allows to achieve both impedance matching and a very low noise figure, and saves a lot of chip area as no bulky inductors are needed. A nullor and a resistive feedback network are employed, and the values of the feedback elements involved are defined in order to fulfill the noise-figure, input impedance and power-gain requirements for an UWB receiver. To ensure circuit stability, frequency compensation is done by means of a phantom zero and the addition of a transistor connected between input and output, thus realizing a multipath structure. The design targets UMC 0.13μm CMOS IC technology and operation from a 1.2-volt supply. From circuit simulations, the power gain of the LNA amounts to 17dB, and the bandwidth spans up to 12GHz. S11 is below -10dB up to 10GHz and the noise figure is below 3dB up to 8GHz, and below 4dB@10GHz. The power consumption equals 14mA. Compared to competitive solutions, using resonating load stages or LC ladder networks, this chip will be much smaller and cheaper; it will use standard CMOS technology, and achieve very low noise, high gain and wide band matching at reasonable power consumption. ©2008 IEEE.

Published
2008

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