Point defects in epitaxial GaN and ZnSe semiconductor layers have been studied using a low-energy positron beam. Ga vacancies are found to be present in n-type GaN grown by metal organic chemical vapor deposition, where the conductivity is due to residual oxygen. When n-type silicon impurity doping is done, clearly less vacancies are observed. In Mgdoped p-type and semi-insulating materials the...

In this study, the effect of different numbers of layers of reduced graphene oxide (RGO) on the ferromagnetic behavior of zinc oxide-reduced graphene oxide (ZnO-RGO) hybrid architectures has been investigated. Scanning and transmission electron microscopy along with x-ray diffraction of these hybrids confirm that ZnO nanorods are wrapped with different numbers of layers of RGO in a controlled w...

Both the origins of the high open circuit voltages VOC in amorphous silicon solar cells having p layers prepared with very high hydrogen dilution and the physical structure of these optimum p layers remain poorly understood topics, with several studies offering conflicting views. This work attempts to overcome the limitations of previous studies by combining insights available from electronic m...

A scene exploration which is quick and complete according to current task is the foundation for most higher scene processing. Many specialized approaches exist in the driver assistance domain (e.g. car recognition or lane marking detection), but we aim at an integrated system, combining several such techniques to achieve sufficient performance. In this work we present a novel approach to this i...

Time series forecasting (TSF) have been widely used in many application areas such as science, engineering, and finance. Usually the characteristics of phenomenon generating a series are unknown and the information available for forecasting is limited to the past values of the series. It is, therefore, important to use an appropriate number of past values, termed lag, for forecasting. Although ...

Selecting suitable charge transport layers and suppressing non-radiative recombination at interfaces with the absorber layer is vital for maximizing efficiency of halide perovskite solar cells. In this study, high-quality thin films devices are fabricated different fullerene-based electron self-assembled monolayers as hole layers. Then, a comparative study significant variety electrical, optica...

In this paper we present a system for personalized offers based on two main components: a) a hybrid method, combining rules and machine learning, to find users that post life events on social media networks; and b) an entity matching algorithm to find out possible relation between the detected social media users and current clients. The main assumption is that, if one can detect the life events...

Rules and ontologies play a key role in the layered architecture of the Semantic Web, as they are used to ascribe meaning to, and to reason about, data on the Web. While the Ontology Layer of the Semantic Web is quite developed, and the Web Ontology Language (OWL) is a W3C recommendation since a couple of years already, the rules layer is far less developed and an active area of research; a num...

To improve weak classifiers bagging and boosting could be used. These techniques are based on combining classifiers. Usually, a simple majority vote or a weighted majority vote are used as combining rules in bagging and boosting. However, other combining rules such as mean, product and average are possible. In this paper, we study bagging and boosting in Linear Discriminant Analysis (LDA) and t...

The papapresents the results of the project CORARC, funded by the Italian Ministry for University and Scientific Research. aimcd at developing a Wcb based system, called SITUS, to support the management of information for archaeological sites. Thc system supports, through a relational database and a G I s server, the archival and management of multiniedia and cartographic data coming fsom a s t...