Multimedia information broadcasting using digital TV channels

In this paper, the structure of a new system to broadcast multimedia information within a digital TV channel is outlined. The proposed scheme is based on the DSM-CC (digital storage media command and control) functions, and uses a newly developed protocol that allows to efficiently convey multimedia information. Such information has the same characteristics of HTML files used in WWW environments, as it may contain text, images, sounds and animation organized as hypertext. The transport structure used is the MPEG-2 transport stream, which is the most popular standardized platform for the development of new digital TV services. Prototype software was developed to encode the file system by means of DSM-CC operations and include it in a MPEG-2 compatible transport system     

Anonymity preserving pattern discovery

It is generally believed that data mining results do not violate the anonymity of the individuals recorded in the source database. In fact, data mining models and patterns, in order to ensure a required statistical significance, represent a large number of individuals and thus conceal individual identities: this is the case of the minimum support threshold in frequent pattern mining. In this paper we show that this belief is ill-founded. By shifting the concept of k -anonymity from the source data to the extracted patterns, we formally characterize the notion of a threat to anonymity in the context of pattern discovery, and provide a methodology to efficiently and effectively identify all such possible threats that arise from the disclosure of the set of extracted patterns. On this basis, we obtain a formal notion of privacy protection that allows the disclosure of the extracted knowledge while protecting the anonymity of the individuals in the source database. Moreover, in order to handle the cases where the threats to anonymity cannot be avoided, we study how to eliminate such threats by means of pattern (not data!) distortion performed in a controlled way.     

A synthesis of the push‐pull fatigue behaviour of plain and notched stainless steel specimens by using the specific heat loss

The energy dissipated to the surroundings as heat in a unit volume of material per cycle, Q, was recently proposed as fatigue damage index, and it was successfully applied to rationalise fatigue data obtained by carrying out stress‐controlled and strain‐controlled fatigue tests on AISI 304 L stainless steel plain and hole specimens. In this paper, it is shown that the Q parameter is independent on thermal and mechanical boundary conditions occurring during experiments. After that, additional stress‐controlled fatigue tests on plain and notched specimens characterised by smaller notch tip radii than those tested previously have been performed. Present data have been compared with previous ones, and it was found that all available results can be synthesised in terms of the energy parameter Q into a unique scatter band, independently on the testing conditions (stress‐controlled or strain‐controlled) and on the specimens' geometry (plain or notched). About 100 data were included in the statistical analysis to characterise the energy‐based scatter band of the material. Finally, some limitations of applicability of the experimental technique adopted in the present paper are discussed.     

Multimedia streaming in Multi-Homed Hybrid Ad Hoc Networks: A model of network connectivity

In this paper we consider the scenario of a Multi-Homed Hybrid Ad Hoc Network, which consists of self-organized and self-configured mobile nodes that make use of two or more fixed gateways to connect to the Internet. Accordingly, different network segments are formed, each one associated with a different gateway. A node can maintain its connectivity to the Internet when moving from a network to another by performing handover procedures and changing its gateway to the Internet. This scenario is quite interesting for its capacity of increasing the geographical extension of a single mobile network. Within this scenario we focus on the modelling of the node connectivity, which is of practical interest for the design of rate control algorithms for multimedia streaming systems. We consider a network structure with gateways placed in a honey cell structure, where nodes move according to the RDMM (Random Direction Mobility Model). We then derive the probabilities for a node to change the route to connect to the Internet and to handover from a network to another, which both cause service interruptions that heavily affect the quality in multimedia streaming services. Numerical results show the accuracy of the proposed theoretical model with respect to simulated data and reveal the benefits of the model in controlling playback buffer starvation occurrences during video streaming.