Giovanni Parodi

No-reference quality assessment of JPEG images by using CBP neural networks

Reliable methods for measuring the perceived image quality are needed to evaluate visual artifacts brought about by digital compression algorithms such as JPEG. This paper presents an objective quality-assessment method based on a circular back-propagation (CBP) neural structure: the network is trained to predict quality ratings, as scored by human assessors, from numerical features that characterize images. As such, the method aims at reproducing perceived image quality, rather than at defining a comprehensive model of the human visual system. The neural model allows one to decouple the task of feature selection from the mapping of these features into a quality score. Experimental results on a public database of test images confirm the effectiveness of the approach.

Enhanced montgomery multiplication on DSP architectures for embedded public-key cryptosystems

Montgomerys algorithm is a popular technique to speed up modular multiplications in public-key cryptosystems. This paper tackles the efficient support of modular exponentiation on inexpensive circuitry for embedded security services and proposes a variant of the finely integrated product scanning (FIPS) algorithm that is targeted to digital signal processors. The general approach improves on the basic FIPS formulation by removing potential inefficiencies and boosts the exploitation of computing resources. The reformulation of the basic FIPS structure results in a general approach that balances computational efficiency and flexibility. Experimental results on commercial DSP platforms confirm both the methods validity and its effectiveness.

Efficient Implementation of SVM Training on Embedded Electronic Systems

The implementation of training algorithms for SVMs on embedded architectures differs significantly from the electronic support of trained SVM systems. This mostly depends on the complexity and the computational intricacies brought about by the optimization process, which implies a Quadratic-Programming problem and usually involves large data sets. This work presents a general approach to the efficient implementation of SVM training on Digital Signal Processor (DSP) devices. The methodology optimizes efficiency by suitably adjusting the established, effective Keerthis optimization algorithm for large data sets. Besides, the algorithm is reformulated to best exploit the computational features of DSP devices and boost efficiency accordingly. Experimental results tackle the training problem of SVMs by involving real-world benchmarks, and confirm both the computational efficiency of the approach.

Influence of the spleen on the blood distribution of the colony-forming cells (CFU-C) in man

The incidence of the blood committed granulocyte progenitor cells (CFU-C) before and after epinephrine administration has been studied in 10 normal, 16 splenomegalic and 8 splenectomized subjects through a double-layer agar culture system. A significant increase of the mean values of CFU-C per milliliter of blood has been observed after epinephrine administration in normal and in splenomegalic subjects. In splenectomized patients the baseline mean values of CFU-C per milliliter of blood were higher than those observed in the other groups of subjects, but they did not increase after epinephrine infusion. The concentration of CFU-C per 10(6) total blood leukocytes was the same in all three groups of subjects and it was not modified by epinephrine administration. Our results seem to indicate that the CFU-C are distributed in two blood compartments, the spleen representing an important section of the marginal compartment of the blood CFU-C.

A sensorless PMSM drive operating in the field weakening region using only one current sensor

A new sensorless PMSM (Permanent Magnet Synchronous Motor) drive with reduced current sensors and field weakening algorithm is presented in this paper. After an overview among the different kinds of sensorless drives that appear in the literature, phase current and position/speed estimators used in this application are explained. Simulation and experimental results are reported.

Embedded Public-key Cryptosystems Via Enhanced Montgomery Multiplication

The Montgomery multiplication algorithm is one of the most efficient techniques used to speed up the modular multiplications required during exponentiation processes in public-key cryptography. In view of the expanding demand of embedded security services, this paper tackles the problem of efficiently supporting Montgomerys method on inexpensive digital circuitry and focuses on the finely integrated product scanning (FIPS) variant of Montgomerys multiplication. The proposed approach improves on the basic FIPS formulation by removing sources of inefficiencies, and boosts the exploitation of the computing resources in digital hardware. Experimental tests on different, commercial DSP devices demonstrate the benefits of the enhanced algorithm implementation and confirm both the method effectiveness in increasing efficiency and its general validity.

Co-occurrence Matrixes for the Quality Assessment of Coded Images

Nonlinear issues complicate the modeling of the user-perceived quality of compressed images, especially when setting up feature-based objective methods. The research described in this paper indicates that the co-occurrence matrix and its features can be effective descriptors, embedding relevant information with respect to the perceptual phenomenon of visual quality. The paper first proposes a statistical approach to correlating objective quantities with subjective empirical evidence, then applies such a protocol to features associated with co-occurrence matrixes. Models from computational intelligence eventually support the actual quality-prediction task. Experimental results on real benchmarks confirm the general validity of the approach.

Embedded Electronics Systems for Training Support Vector Machines

Training support vector machines (SVMs) requires efficient architectures, endowed with agile memory handling and specific computational features. Such a process is often supported by embedded implementations on dedicated machinery, for example in applications requiring on-line training abilities. The paper presents a general approach to the efficient implementation of SVM training on digital signal processor (DSP) devices. The methodology optimizes efficiency by a twofold approach: first, it suitably adjusts an established, effective training algorithm for large data sets; secondly, it reformulates the algorithm to best exploit the computational features of DSP devices and boost efficiency accordingly. Experimental results tackle the training problem of SVMs by using a high-end DSP architecture on real-world benchmarks, and confirm both the effectiveness and the general validity of the approach.

Influence of the spleen on the blood distribution of the leukocytes producing colony-stimulating activity (CSA) in man

SummaryThe colony-stimulating activity (CSA) produced by the blood leukocytes has been studied before and after epinephrine administration in ten normal, 15 splenomegalic, and seven splenectomized subjects through a double layer agar culture system.A significant increase of mean values of the CSA per milliliter produced by blood monocytes has been observed after epinephrine administration in the groups of normal and of splenomegalic subjects. In the group of splenectomized subjects the baseline mean value of CSA per milliliter of blood was higher than those observed in the other groups, but it did not show any increase after epinephrine infusion.The CSA produced by 106 blood leukocytes was similar in all three groups of subjects, and it was not similarly modified by epinephrine administration.Our results seem to indicate that the leukocytes producing CSA are distributed within two rapidly exchangeable blood compartments, the spleen representing an important section of the marginal compartment of blood monocytes.