A CMOS analog-digital audio processor for a portable radiotelephone

A mixed analog-digital (A/D) integrated circuit (IC) specifically designed to realize the audio processing functions needed for a portable radiotelephone (PRT) application is described. Multirate signal processing techniques are used to reduce the capacitance spread, and hence the overall silicon area, of the chip, as well as to minimize the settling requirements of the amplifiers for lower power consumption. This, together with programmable power-saving control circuitry also incorporated on-chip, considerably extends the lifetime of the battery. A semicustom design methodology is employed to implement such an application-specific integrated circuit (ASIC) in a 3-μm CMOS double-poly processing technology. Experimental results are presented to demonstrate the correct operation and functionality of the prototype chips     

HLA class-I-soluble antigen serum levels in liver transplantation. A predictor marker of acute rejection

The serum levels of sHLA-I have been determined in 16 patients following liver transplantation. sHLA-I levels did not show remarkable variations in six patients without evidence of transplant-related complications. sHLA-I levels strongly increased in 10 patients undergoing acute rejection episodes. In these patients, an average 20% daily increase of sHLA-I levels was detected on the 6 days preceding and on the 2 days following the rejection episode. A fast decrease of sHLA-I levels was observed in seven patients following treatment of acute rejection with anti-CD3 mAb. The serum level of sHLA-I antigens positively correlated with ALT serum level and inversely correlated with PT. The determination of sHLA-I in serum may therefore be proposed as a useful marker in the monitoring of patients following liver transplantation. The increase of sHLA-I antigens may predict the onset of acute rejection whereas their decrease may be related to a good response of acute rejection to immunosuppressive treatment.     

A monitoring tool of workers' activity at Video Display Terminals for investigating VDT-related risk of musculoskeletal disorders

Today the risk factors related to the use of Video Display Terminals (VDT) are assessed by investigating the actual activities at the VDT through subjective questionnaires and/or quantitative measurements. Questionnaire outcomes are quite imprecise and seldom objective. Quantitative measurements (EMG recordings, electrogoniometers, motion analysis systems) mostly prevent subjects from moving freely while working at the VDT. The paper presents an automatic tool for the monitoring of activity at VDTs, using a quantitative, objective approach. The suitability of the proposed tool was fully tested in the laboratory, both in terms of functionalities, accuracy of the tool, and acceptance by the subjects involved. The outcomes show that the tool allows for a detailed analysis of VDT activities and may be used to improve VDT-related risk analysis with high accuracy and good acceptance by workers.     

Improved similarity trees and their application to visual data classification

An alternative form to multidimensional projections for the visual analysis of data represented in multidimensional spaces is the deployment of similarity trees, such as Neighbor Joining trees. They organize data objects on the visual plane emphasizing their levels of similarity with high capability of detecting and separating groups and subgroups of objects. Besides this similarity-based hierarchical data organization, some of their advantages include the ability to decrease point clutter; high precision; and a consistent view of the data set during focusing, offering a very intuitive way to view the general structure of the data set as well as to drill down to groups and subgroups of interest. Disadvantages of similarity trees based on neighbor joining strategies include their computational cost and the presence of virtual nodes that utilize too much of the visual space. This paper presents a highly improved version of the similarity tree technique. The improvements in the technique are given by two procedures. The first is a strategy that replaces virtual nodes by promoting real leaf nodes to their place, saving large portions of space in the display and maintaining the expressiveness and precision of the technique. The second improvement is an implementation that significantly accelerates the algorithm, impacting its use for larger data sets. We also illustrate the applicability of the technique in visual data mining, showing its advantages to support visual classification of data sets, with special attention to the case of image classification. We demonstrate the capabilities of the tree for analysis and iterative manipulation and employ those capabilities to support evolving to a satisfactory data organization and classification.     

Neural network ensembles: immune-inspired approaches to the diversity of components

This work applies two immune-inspired algorithms, namely opt-aiNet and omni-aiNet, to train multi-layer perceptrons (MLPs) to be used in the construction of ensembles of classifiers. The main goal is to investigate the influence of the diversity of the set of solutions generated by each of these algorithms, and if these solutions lead to improvements in performance when combined in ensembles. omni-aiNet is a multi-objective optimization algorithm and, thus, explicitly maximizes the components’ diversity at the same time it minimizes their output errors. The opt-aiNet algorithm, by contrast, was originally designed to solve single-objective optimization problems, focusing on the minimization of the output error of the classifiers. However, an implicit diversity maintenance mechanism stimulates the generation of MLPs with different weights, which may result in diverse classifiers. The performances of opt-aiNet and omni-aiNet are compared with each other and with that of a second-order gradient-based algorithm, named MSCG. The results obtained show how the different diversity maintenance mechanisms presented by each algorithm influence the gain in performance obtained with the use of ensembles.     

Improving a firefly meta-heuristic for multilevel image segmentation using Tsallis entropy

In this paper we show that the non-extensive Tsallis entropy, when used as kernel in the bio-inspired firefly algorithm for multi-thresholding in image segmentation, is more efficient than using the traditional cross-entropy presented in the literature. The firefly algorithm is a swarm-based meta-heuristic, inspired by fireflies-seeking behavior following their luminescence. We show that the use of more convex kernels, as those based on non-extensive entropy, is more effective at \(5\,\%\) of significance level than the cross-entropy counterpart when applied in synthetic spaces for searching thresholds in global minimum.     

Schwannomas of the digestive tract. Observations on a case localizing in the ileum

The schwannomas are rare tumors taking origin from Schwann's cells; even rarer is their location at a peripheral level. Even if they show the macroscopic and microscopic characteristics of a benign tumor, it is possible that they engage malignant course, with possibility of recurrency and of distant metastasis. In the alimentary tract the schwannomas reveal with repeated episodes of digestive hemorrhage which could engage, according to the location, the characters of enterorrhagia or melena. Arteriography has the higher diagnostic sensibility, in course of bleeding. The CT could demonstrate a submucosal neoplasia. The diagnosis of schwannomas is based on the immunohistochemical search of the protein S100, that allows to differentiate them from the tumors of muscular origin, having such tumors common histological and cytological aspects. The schwannomas are today set in the widest chapter of the so-called "stromal tumors of the gastrointestinal tract" (GISTs) with an indefinite malignancy which need surgical excision and an attentive follow-up. The authors report a case of schwannoma located at the first jejunal loop, having had repeated episodes of digestive hemorrhage. The diagnosis was based on the selective arteriography of the upper mesenteric artery and the immunohistochemical search of the protein S100. The surgical treatment consisted of the resection of the jejunal loop, after having sought for eventual multiple locations of the neoplasia.     

Scheduling computations with provably low synchronization overheads

Journal of Scheduling - We present a Work Stealing scheduling algorithm that provably avoids most synchronization overheads by keeping processors’ deques entirely private by default and only...