A comprehensive analysis of the geometry of TDOA maps in localisation problems

In this manuscript we consider the well-established problem of TDOA-based source localization and propose a comprehensive analysis of its solutions for arbitrary sensor measurements and placements. More specifically, we define the TDOA map from the physical space of source locations to the space of range measurements (TDOAs), in the specific case of three receivers in 2D space. We then study the identifiability of the model, giving a complete analytical characterization of the image of this map and its invertibility. This analysis has been conducted in a completely mathematical fashion, using many different tools which make it valid for every sensor configuration. These results are the first step towards the solution of more general problems involving, for example, a larger number of sensors, uncertainty in their placement, or lack of synchronization.Comment: 51 pages (3 appendices of 12 pages), 12 figure

Health Inequalities and the Welfare State in European Families

Using EU-Silc data from 2005, our aim in this article is to estimate how self-assessed health and the gradient between education and health vary among individuals in different European countries, considering their contextual socioeconomic vulnerability. In order to do this, we use a hierarchical model with individuals nested in households at the second level, and in various European countries at the third level. Our main research interest is on the modelling variables associated with better health conditions and their improvement or worsening according not only to micro/ individual and macro/national levels but also to the household: a level on which social protection (of whatever nature) exerts its influence. Diferent household contexts receive different amounts of resources, by transfers, social care and health services, which could directly affect health and also modify the gradient between education and health. Moreover, these relations are likely to change among European countries, on the basis of various welfare assets, as the identification of beneficiaries\u27 categories and the weight of category-based measures on the overall welfare expenditure varies among countries and among welfare models

The algebro-geometric study of range maps

Localizing a radiant source is a widespread problem to many scientific and technological research areas. E.g. localization based on range measurements stays at the core of technologies like radar, sonar and wireless sensors networks. In this manuscript we study in depth the model for source localization based on range measurements obtained from the source signal, from the point of view of algebraic geometry. In the case of three receivers, we find unexpected connections between this problem and the geometry of Kummer's and Cayley's surfaces. Our work gives new insights also on the localization based on range differences.Comment: 38 pages, 18 figure

Source localization and denoising: a perspective from the TDOA space

In this manuscript, we formulate the problem of denoising Time Differences of Arrival (TDOAs) in the TDOA space, i.e. the Euclidean space spanned by TDOA measurements. The method consists of pre-processing the TDOAs with the purpose of reducing the measurement noise. The complete set of TDOAs (i.e., TDOAs computed at all microphone pairs) is known to form a redundant set, which lies on a linear subspace in the TDOA space. Noise, however, prevents TDOAs from lying exactly on this subspace. We therefore show that TDOA denoising can be seen as a projection operation that suppresses the component of the noise that is orthogonal to that linear subspace. We then generalize the projection operator also to the cases where the set of TDOAs is incomplete. We analytically show that this operator improves the localization accuracy, and we further confirm that via simulation.Comment: 25 pages, 9 figure

A MIOCENE CERVID FROM THE TORRENTE MORRA SEQUENCE (COLLESALVETTI, PISA, ITALY)

A well preserved fossil left tibia of artiodactyl was recently found along Torrente Morra, in the surroundings of Collesalvetti (15 Kms South of Pisa). The bone is embedded in Upper Messinian deltaic sediments which outcrop patchily in the area. The specimen can be referred to a primitive cervid and shows morphological characters and proportions very close to those of the tibiae of extant roe deer, Capreolus capreolus. The find is particularly significant because continental mammals have never been reported before from the Miocene deposits of this area. A possible reference to a primitive roe deer would be consistent with Late Miocene macrofloral and palynological evidence from this area, which attest to a transition from a subtropical forested environment to a temperate Mediterranean one.&nbsp

Composti naturali e derivati semisintetici quali potenziali agenti terapeutici per il morbo di Alzheimer

Il morbo di Alzheimer (AD) costituisce una tragedia di immense proporzioni, sia per il singolo individuo che per la società. In questa tesi sono stati analizzati i principali eventi fisiologici coinvolti nella patogenesi dell’Alzheimer. Questi comprendono l’aggregazione della proteina amiloide Alo stress ossidativo determinato da specie reattive dell’ossigeno (ROS), enzimi del sistema colinergico come l’AChE e la BuChE e la formazione di complessi biometallici come ad esempio quelli di Cu e Zn. In particolare l’interesse è stato poi rivolto allo studio di composti naturali e dei loro derivati semisintetici che hanno evidenziato, nelle relative valutazioni biologiche, una certa attività nei confronti di uno o più target (terapia multifunzionale), coinvolti nell’eziopatogenesi dell’Alzheimer

Wavelet-based video coding: optimal use ofmotion information for the decoding of spatially scaled video sequences

In this paper we discuss the how to best handle motion vectors in spatially scalable wavelet-based video decoders. Motion vectors with full resolution are normally included in the bit-steams relative to spatially scaled version of a video sequence. When a low-resolution version of the original sequence is received, the decoder must scale the motion vectors accordingly. We will show that the motion vector scaling (truncation) is not the best solution and that better results can be obtained by interpolating the subsampled sequence to full resolution using of the wavelet synthesis low-pass filter. We illustrate the results of experiments carried out with an in-band wavelet-based fully scalable coder that performs spatial analysis, followed by temporal filtering. Emphasis is given to the computation of the Overcomplete DWT in the spatially scalable scenario. 1

Efficient Localization and Tracking of Two Acoustic Sources using Particle Filters with Swarm Intelligence

Publication in the conference proceedings of EUSIPCO, Poznan, Poland, 200