Information Horizons in Networks

We investigate and quantify the interplay between topology and ability to send specific signals in complex networks. We find that in a majority of investigated real-world networks the ability to communicate is favored by the network topology on small distances, but disfavored at larger distances. We further discuss how the ability to locate specific nodes can be improved if information associated to the overall traffic in the network is available.Comment: Submitted top PR

Deformation mechanisms underlying tension-compression asymmetry in magnesium alloy ZK60 revealed by acoustic emission monitoring

© 2014 Elsevier B.V. This study is aimed at clarifying the microscopic mechanisms that determine a pronounced asymmetry of plastic deformation with respect to tension and compression in magnesium alloys, even having a random texture. The specific object of the present investigation is the Mg-Zn-Zr alloy ZK60. The mechanisms in question are based on a synergistic interplay between dislocation slip and deformation twinning. The details of the relative contributions of these principal processes were studied by monitoring the acoustic emission (AE) underpinned by robust AE signal classification developed recently. Through the cluster analysis of AE time series in spectral domain, the sequences of the predominant deformation mechanisms were identified for early stages of cyclic loading with opposite directions of the first loading excursion into tension or compression

Tawney and the third way

From the 1920s to the 1950s R. H. Tawney was the most influential socialist thinker in Britain. He articulated an ethical socialism at odds with powerful statist and mechanistic traditions in British socialist thinking. Tawney's work is thus an important antecedent to third way thinking. Tawney's religiously-based critique of the morality of capitalism was combined with a concern for detailed institutional reform, challenging simple dichotomies between public and private ownership. He began a debate about democratizing the enterprise and corporate governance though his efforts fell on stony ground. Conversely, Tawney's moralism informed a whole-hearted condemnation of market forces in tension with both his concern with institutional reform and modern third way thought. Unfortunately, he refused to engage seriously with emergent welfare economics which for many social democrats promised a more nuanced understanding of the limits of market forces. Tawney's legacy is a complex one, whose various elements form a vital part of the intellectual background to current third way thinking

Critical Dynamics of Burst Instabilities in the Portevin-Le Chatelier Effect

We investigate the Portevin-Le Chatelier effect (PLC), by compressing Al-Mg alloys in a very large deformation range, and interpret the results from the viewpoint of phase transitions and critical phenomena. The system undergoes two dynamical phase transitions between intermittent (or "jerky") and "laminar" plastic dynamic phases. Near these two dynamic critical points, the order parameter 1/\tau of the PLC effect exhibits large fluctuations, and "critical slowing down" (i.e., the number $\tau$ of bursts, or plastic instabilities, per unit time slows down considerably).Comment: the published 4-page version is in the PRL web sit

A framework for data quality and feedback in participatory sensing

The rapid adoption of mobile phones by society over the last decade and the increasing ability to capture, classifying, and transmit a wide variety of data (image, audio, and location) have enabled a new sensing paradigm - where humans carrying mobile devices can act as sensor systems. Human-in-the-loop sensor systems raise many new challenges in areas of sensor data quality assessment, mobility and sampling coordination, and user interaction procedures. To this end, we outline our initial steps in designing an incentive based reputation system for assessing data quality, provide an overview of techniques to obtain fine grained contextual information in mobile situations, and detail feedback mechanisms to enable more interactive and informative sensor systems