Tecniche di graph mining per l'analisi di reti sociali

La tesi presenta il problema dell’estrazione di conoscenza da reti sociali utilizzando tecniche di graph mining (GM). In particolare si propongono soluzioni per la creazione di un indice di clustering e la ricerca di pattern in un grafo

Deep p-Ring Trench Termination: An Innovative and Cost-Effective Way to Reduce Silicon Area

A new type of high voltage termination, namely the “deep p-ring trench” termination design for high voltage, high power devices is presented and extensively simulated. Termination of such devices consumes a large proportion of the chip size; the proposed design concept not only reduces the termination silicon area required, it also removes the need for an additional mask as is the case of the traditional p+ ring type termination. Furthermore, the presence of the p-ring under and around the bottom of the trench structure reduces the electric field peaks at the corners of the oxide which results in reduced hot carrier injection and improved device reliabilit

Quantum-well-laser mirror degradation investigated by microprobe optical spectroscopy

A study of facet degradation of InGaAs quantum well lasers is reported. We tune up a Raman and photoluminescence micro-probe technique for determining the crystal structure and the temperature profile of the cladding layer, in steps of approximately 1 micrometer, with a temperature resolution better than 1 degree Kelvin. The cladding layer composition and cross- section temperature profile have been monitored during operation. A clear correlation between the facet degradation and the type of protective coating is found

Problematic mobile phone use in adolescence:a cross-sectional study

Aim: In recent years, mobile phone use has become increasingly common among Italian youth, while a growing scientific literature has been identifying the occurrence of a problematic mobile phone use which seems to share some features of other conditions often referred to as behavioural addictions. The study aimed to assess the prevalence of problematic mobile phone use in a population of Italian adolescents and its association with other behavioural addictions. Subjects and methods: The Mobile Addiction Test (MAT) was administered to 2,790 high school students from Barletta, an Italian town, together with the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA), the Compulsive Buying Scale (CBS), the Internet Addiction Test (IAT), the Exercise Addiction Inventory (EAI), the Work Addiction Risk Test (WART). Results: MAT scores fitted a Gaussian distribution model. Scores ≥ 17 was found as a cut-off value over which identifying problematic mobile phone users. Overall prevalence of problematic mobile phone use was 6.3%; this condition was associated with other behavioural addictions like compulsive buying. Conclusion: Problematic mobile phone use in adolescence should become a public health issue, and it could be a cause of health problems and social costs. © 2011 Springer-Verlag

Apparatus for simultaneous DLS-SANS investigations of dynamics and structure in soft matter

Dynamic Light Scattering (DLS) and Small-Angle Neutron Scattering (SANS) are two key tools with which to probe the dynamic and static structure factor, respectively, in soft matter. Usually DLS and SANS measurements are performed separately, in different laboratories, on different samples and at different times. However, this methodology has particular disadvantages for a large variety of soft materials which exhibit high sensitivity to small changes in fundamental parameters such as waiting times, concentration, pH, ionic strength, etc. Here we report on a new portable DLS-SANS apparatus that allows one to simultaneously measure both the microscopic dynamics (through DLS) and the static structure (through SANS) on the same sample. The apparatus has been constructed as a collaboration between two laboratories, each an expert in one of the scattering methods, and was commissioned on the \textit{LOQ} and \textit{ZOOM} SANS instruments at the ISIS Pulsed Neutron \& Muon Source, U.K

Coping strategies in adolescence: a preliminary study of gender differences

Las estrategias de afrontamiento varían en función de la persona cuando esta tiene que enfrentarse a una situación potencial de estrés. Este estudio se centra en la variabilidad de las estrategias de afrontamiento implementadas por individuos ante situaciones potencialmente estresantes, poniendo especial énfasis en cómo el género puede influir en la utilización de dichas estrategias. Se realizó una investigación cuyo propósito fue examinar los niveles de uso de diversas estrategias de afrontamiento entre adolescentes y explorar las posibles discrepancias basadas en el género. Para lograr este objetivo, se utilizó la Escala de Afrontamiento para Niños (EAN) para evaluar a estudiantes adolescentes de una región específica de Italia. Los resultados indicaron que la estrategia de afrontamiento más comúnmente adoptada fue la evitación cognitiva, seguida de compartir el problema con otros. La evitación de conductas y mantener los problemas para uno mismo también fueron estrategias empleadas, mientras que la búsqueda activa de información y guía fue la menos utilizada. Los hallazgos de este estudio resaltan la importancia de considerar cuáles son las estrategias de afrontamiento más y menos adaptativas al desarrollar programas destinados a fomentar comportamientos proactivos durante la adolescencia.Coping strategies vary depending on the individual when facing potential stressors. This study focuses on the variability of coping strategies implemented by individuals in potentially stressful situations, with a particular emphasis on how gender may influence the utilization of these strategies. An investigation was conducted to examine the levels of use of various coping strategies among adolescents and explore potential gender-based discrepancies. To achieve this goal, the Children's Coping Scale (CCS) was utilized to assess adolescent students in a specific region of Italy. Results indicated that the most adopted coping strategy was cognitive avoidance, followed by sharing the problem with others. Avoidance behaviors and keeping problems to oneself were also employed strategies, while active information seeking, and guidance were the least used. Findings from this study emphasize the importance of considering which coping strategies are adaptive when developing programs aimed at fostering proactive behaviors during adolescence