On the detection of card-sharing traffic through wavelet analysis and Support Vector Machines

In the last years, the interest in methods and techniques for circumventing the security of the available digital video broadcasting systems is continuously increasing. Digital TV providers are struggling to restrict access to their video contents only to authorized users, by deploying more and more sophisticated conditional access systems. At the state-of-the-art, the most significant menace is the card-sharing activity which exploits a known weakness allowing an authorized subscriber to provide access to digital contents to a potentially large group of unauthorized ones connected over a communication network. This is usually realized by using ad hoc customized devices. Detecting the presence of these illegal systems on a network, by recognizing their related traffic is an issue of primary importance. Unfortunately, to avoid the identification of such traffic, payload obfuscation strategies based on encryption are often used, hindering packet inspection techniques.This paper presents a strategy for the detection of card-sharing traffic, empowered by machine-learning-driven traffic classification techniques and based on the natural capability of wavelet analysis to decompose a traffic time series into several component series associated with particular time and frequency scales and hence allowing its observation at different frequency component levels and with different resolutions. These ideas have been used for the proof-of-concept implementation of an SVM-based binary classification scheme that relies only on time regularities of the traffic and not on the packet contents and hence is immune to payload obfuscation techniques.     

Solvent vapor treatment controls surface wettability in PMMA femtosecond-laser-ablated microchannels

A solvent vapor treatment was applied to femtosecond-laser-ablated microchannels in PMMA to selectively restore the original hydrophilic wetting behavior of the pristine surface. The hydrophobic surface of the microchannels from the submicron porosity induced by ablation becomes smoother and more transparent after the treatment. This simple and low-cost method, together with suitable masking, can produce wettability patterns that may be exploited to develop passive microfluidic elements such as valves and mixers.     

Optimal radio resources and transmission formats assignment in OFDMA systems

The problem of assigning radio resources and transmission formats to users in the downlink of an OFDMA network is addressed. In particular, a single cell environment with a realistic interference model and a margin adaptive approach is considered, i.e., the aim is of minimizing the total transmission power while maintaining a certain given rate for each user. The computational complexity issues of the problem are discussed, and an approximation analysis is presented. Heuristic approaches, based on rounding techniques and graph models, are also proposed. Computational experiences show that, in a comparison with a commercial state-of-the-art optimization solver and with alternatives from the literature, the proposed algorithms are effective in terms of solution quality and CPU times.     

Three-dimensional optical data storage through multi-photon confocal microscopy and imaging

Three dimensional optical data storage is one of the most promising tools to respond to the always growing demand for high data storage capacity. Here, we focused a femtosecond laser source by means of a confocal microscope onto different transparent recording media. The purpose of the study is to probe the capability of the system to independently address different data layers within the storage medium achieving thus three dimensional data storage. We demonstrated the possibility to write superposed independent layers of data due to either multiphoton excitation or to local optical breakdown and the performances observed in the different types of media used are compared.     

Flexible electronics: Prediction of substrate deformation during different steps of the lithography process

A numerical model was developed to simulate the micro-deformations of a polymeric substrate due to lithographic processing of different layers of a transistor-like structure. The results of the model were validated with the results from experiments. The model, a mechanical-thermal-hygroscopic model, takes into account the dimensional effects of temperature, moisture and stresses. It also includes the temperature dependent visco-elastic behaviour of the polymer substrate. The model can be used to predict overlay accuracies between different functional layers introduced by the lithographic process. It can also be used to understand the underlying processes such that it provides a tool to improve the overlay accuracy during actual processing.     

Mix design and performance analysis of asphalt concretes with electric arc furnace slag

The paper presents the results of a laboratory study, aimed at verifying the possibility to use two particular typologies of electric arc furnace (EAF) steel slags, in substitution of the natural aggregates, in the composition of wearing course asphalt concrete for flexible pavements. The experimental research has been articulated in a preliminary study of the chemical, leaching, physical, and mechanical properties of the EAF steel slag, and in the following mix design and performance characterisation of the bituminous conglomerates, through gyratory compaction tests, permanent deformations tests, Stiffness Modulus tests at various temperatures, fatigue tests and indirect tensile strength tests. All the mixtures with EAF slag have satisfied the requisites for acceptance in the road sector technical standards, thus resulting as suitable for use in the construction of road infrastructures, moreover presenting higher mechanical characteristics than those of the corresponding asphalts with full natural aggregate.     

Post-cracking behaviour of steel and macro-synthetic fibre-reinforced concretes

The present paper describes the results of an experimental investigation on the performances of concrete specimens reinforced with either steel or macro-synthetic fibres under three-point bending. Steel fibres are often used to improve the flexural toughness of concrete and are used in various structural applications while synthetic fibres are more often used to reduce crack opening due to shrinkage. Macro-synthetic fibres have been proposed more recently with the aim of creating an alternative to steel fibres in structural applications but their use is still limited.In the tests performed, specimens cast with the same concrete mix, but containing different dosages of either steel or macro-synthetic fibres, were used and compared. In general steel fibres were more efficient in increasing the toughness of concrete than macro-synthetic fibres, even though their results were significantly more scattered.Test results were used to calculate the parameters of stress-crack opening relations via inverse analysis using a cracked hinge model. This numerical model provided results, in terms of force-Crack Mouth Opening Displacement (CMOD) curves, in very good agreement with the experimental data.     

Project Network Interdependency Alignment: New Approach to Assessing Project Effectiveness

The engineering and construction industry has evolved to a task-centric approach to evaluating the effectiveness of projects. However, a narrow task-based view of project network logic neglects the coordination of communication and knowledge exchanges across the project organizational network. This paper departs from traditional approaches to introduce a new approach to assessing project effectiveness that focuses on alignment of actual knowledge exchanges with knowledge exchange requirements across task-organization network dyads. A new modeling approach is introduced, called Project Network Interdependency Alignment. Project Network Interdependency Alignment identifies potentially excessive or insufficient communication and knowledge exchanges that can make projects ineffective. The modeling approach is introduced and retrospectively validated by using a building renovation construction project. The case study demonstrates that the approach can provide project managers with the capacity to analyze task and organizational network interdependence on projects and the critical capability to identify misalignments that impede project effectiveness.     

Parent–offspring conflict theory: An evolutionary framework for understanding conflict within human families.

Decades of research demonstrate that conflict shapes and permeates a broad range of family processes. In the current article, we argue that greater insight, integration of knowledge, and empirical achievement in the study of family conflict can be realized by utilizing a powerful theory from evolutionary biology that is barely known within psychology: parent–offspring conflict theory (POCT). In the current article, we articulate POCT for psychological scientists, extend its scope by connecting it to the broader framework of life history theory, and draw out its implications for understanding conflict within human families. We specifically apply POCT to 2 instances of early mother–offspring interaction (prenatal conflict and weaning conflict); discuss the effects of genetic relatedness on behavioral conflict between parents, children, and their siblings; review the emerging literature on parent–offspring conflict over the choice of mates and spouses; and examine parent–offspring conflict from the perspective of imprinted genes. This review demonstrates the utility of POCT, not only for explaining what is known about conflict within families but also for generating novel hypotheses, suggesting new lines of research, and moving us toward the “big picture” by integrating across biological and psychological domains of knowledge. (PsycINFO Database Record (c) 2011 APA, all rights reserved)