Ricerc@Sapienza

This paper presents a selection of research topics related to nano-electromagnetic compatibility (nano-EMC) issues in emerging carbon nanoelectronics. Carbon-based nano-interconnect modeling and analysis are first introduced. Then, the key techniques of carbon nanotube-filled through-silicon vias and carbon- based passive devices are discussed.

Mobile biometrics technologies are nowadays the new frontier for secure use of data and services, and are considered particularly important due to the massive use of handheld devices in the entire world. Among the biometric traits with potential to be used in mobile settings, the iris/ocular region is a natural candidate, even considering that further advances in the technology are required to meet the operational requirements of such ambitious environments. Aiming at promoting these advances, we organized the Mobile Iris Challenge Evaluation (MICHE)-I contest.

The paper presents experiments with the home-made, low-cost prototype of a sensor-equipped pen for handwriting-based biometric authentication. The pen allows to capture the dynamics of user writing on normal paper, while producing a kind of password (passphrase) chosen in advance. The use of a word of any length instead of the user's signature makes the approach more robust to spoofing, since there is no repetitive pattern to steal. Moreover, if the template gets violated, this is much less harmful than signature catch.

The interdependency of multiple networks makes today's infrastructures more vulnerable to failures. Prior works mainly focused on robust network design and recovery strategies after failures, given complete knowledge of failure location. Nevertheless, in real-world scenarios, the location of failures might be unknown or only partially known. In this work, we focus on cascading failures involving the power grid and its communication network with imprecision in failure assessment.

In this paper we focus on gender classification from face images. Despite advances in equipment as well as methods, automatic face image processing for recognition or even just for the extraction of demographics, is still a challenging task in unrestricted scenarios. Our tests are aimed at carrying out an extensive comparison of a feature based approach with two score based ones. When directly using features, we first apply different operators to extract the corresponding feature vectors, and then stack such vectors. These are classified by a SVM-based approach.

Mobile biometrics represent the new frontier of authentication. The most appealing feature of mobile devices is the wide availability and the presence of more and more reliable sensors for capturing biometric traits, e.g., cameras and accelerometers. Moreover, they more and more often store personal and sensitive data, that need to be protected. Doing this on the same device using biometrics to enforce security seems a natural solution. This makes this research topic attracting and generally promising.

We study the question of fair clustering under the disparate impact doctrine, where each protected class must have approximately equal representation in every cluster. We formulate the fair clustering problem under both the k-center and the k-median objectives, and show that even with two protected classes the problem is challenging, as the optimum solution can violate common conventions - for instance a point may no longer be assigned to its nearest cluster center!

The analysis of signals defined over a graph is relevant in many applications, such as social and economic networks, big data or biological networks, and so on. A key tool for analyzing these signals is the so-called graph Fourier transform (GFT). Alternative definitions of GFT have been suggested in the literature, based on the eigen-decomposition of either the graph Laplacian or adjacency matrix.

The tomographic algorithms commonly used to process ground penetrating radar (GPR) data assume the scattering phenomenon activated by ideal sources. This can be considered an adequately accurate assumption if the actual GPR antenna presents almost nondirectional features, but should instead properly revisited when a target is illuminated by means of more collimated near-field distributions.

Aim of the present study was to test and validate an ex vivo predictive model for the evaluation of the shrinkage occurring in hepatic tissue during a microwave thermal ablation procedure. Microwave ablation (N=134) was conducted with three different commercial devices on cubes of ex vivo liver (15-40\pm 2 mm side) embedded in agar phantoms. 50-60W was applied for 1-10 min duration. Pre-and post-ablation dimensions of the samples, as well as the extent of carbonization and coagulation were measured.