BinCam:designing for engagement with Facebook for behavior change

Abstract. In this paper we continue work to investigate how we can engage young adults in behaviors of recycling and the prevention of food waste through social media and persuasive and ubiquitous computing systems. Our previous work with BinCam, a two-part design combining a system for the collection of waste-related behaviors with a Facebook application, suggested that although this ubiquitous system could raise awareness of recycling behavior, engagement with social media remained low. In this paper we reconsider our design in terms of engagement, examining both the theoretical and practical ways in which engagement can be designed for. This paper presents findings from a new user study exploring the redesign of the social media interface following this analysis. By incorporating elements of gamification, social support and improved data visualization, we contribute insights on the relative potential of these techniques to engage individuals across the lifespan of a system’s deployment

Analysis of Neighbourhoods in Multi-layered Dynamic Social Networks

Social networks existing among employees, customers or users of various IT systems have become one of the research areas of growing importance. A social network consists of nodes - social entities and edges linking pairs of nodes. In regular, one-layered social networks, two nodes - i.e. people are connected with a single edge whereas in the multi-layered social networks, there may be many links of different types for a pair of nodes. Nowadays data about people and their interactions, which exists in all social media, provides information about many different types of relationships within one network. Analysing this data one can obtain knowledge not only about the structure and characteristics of the network but also gain understanding about semantic of human relations. Are they direct or not? Do people tend to sustain single or multiple relations with a given person? What types of communication is the most important for them? Answers to these and more questions enable us to draw conclusions about semantic of human interactions. Unfortunately, most of the methods used for social network analysis (SNA) may be applied only to one-layered social networks. Thus, some new structural measures for multi-layered social networks are proposed in the paper, in particular: cross-layer clustering coefficient, cross-layer degree centrality and various versions of multi-layered degree centralities. Authors also investigated the dynamics of multi-layered neighbourhood for five different layers within the social network. The evaluation of the presented concepts on the real-world dataset is presented. The measures proposed in the paper may directly be used to various methods for collective classification, in which nodes are assigned to labels according to their structural input features.Comment: 16 pages, International Journal of Computational Intelligence System

Using social network sites in Higher Education: An experience in business studies

In the past 5 years the impact of Web 2.0 in new generations has been remarkably significant (Pew Research Center, 2010). This paper reports on an experience in the use of Social Network Sites (SNS) to support student involvement with the subject and to develop basic skills. According to students’ opinion, the experience was deemed as positive. They considered that the experience contributed to a higher engagement with the subject and a deeper collaboration with other students and teaching staff. As a result, the majority of students would prefer the use of SNS as a first option if they had to enrol again in the subject. Regarding the relationships between academic performance and use of the SNS, two different student profiles were identified based on usage patterns of the platform. Students with a more intensive use of the site showed a significantly better performance than students with a low usage profile.This work was partially supported by the Junta de Andalucía – FEDER (Proyectos de Excelencia: SEJ-02670

Evidence for Shock Acceleration and Intergalactic Magnetic Fields in a Large-Scale Filament of Galaxies ZwCl 2341.1+0000

We report the discovery of large-scale diffuse radio emission from what appears to be a large-scale filamentary network of galaxies in the region of cluster ZwCl 2341.1+0000, and stretching over an area of at least $6 h^{-1}_{50}$ Mpc in diameter. Multicolour CCD observations yield photometric redshifts indicating that a significant fraction of the optical galaxies in this region is at a redshift of z=0.3. This is supported by spectroscopic measurements of 4 galaxies in the SDSS survey at a mean z=0.27. We present VLA images at 20 cm (NVSS) and 90 cm wavelengths, showing the detailed radio structure of the filaments. Comparison with the VLA high resolution FIRST radio survey shows that the diffuse emission is not due to known individual point sources. The diffuse radio-emission has a spectral index $\alpha \lesssim -0.5$, and is most likely synchrotron emission from relativistic charged particles in an inter-galactic magnetic field. Furthermore, this optical/radio structure is detected in X-rays by the ROSAT all-sky survey. It has a 0.1--2.4 keV luminosity of about $10^{44}$ erg s$^{-1}$ and shows an extended highly non-relaxed morphology. These observations suggest that ZwCl 2341.1+0000 is possibly a proto-cluster of galaxies in which we are witnessing the process of structure formation. We show (both analytically and by numerical simulations) that the energetics of accretion shocks generated in forming large-scale structures are sufficient to produce enough high energy cosmic-ray (CR) electrons required to explain the observed radio emission, provided a magnetic field of strength of about 1 micro Gauss is present there.Thus it is the first evidence of cosmic-ray particle acceleration and magnetic fields occuring on a super-cluster scale. (Abridged)Comment: Replaced with the published version. The published paper can be accessed from http://www.elsevier.com/gej-ng/10/33/29/71/56/53/article.htm

Recent Advances in Understanding Particle Acceleration Processes in Solar Flares

We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in three-dimensional magnetic field configurations (e.g., current sheets, collapsing traps, separatrix regions) and stochastic acceleration in a turbulent environment. Fluid, test-particle, and particle-in-cell approaches are used and results compared. While these studies show considerable promise in accounting for the various observational manifestations of solar flares, they are limited by a number of factors, mostly relating to available computational power. Not the least of these issues is the need to explicitly incorporate the electrodynamic feedback of the accelerated particles themselves on the environment in which they are accelerated. A brief prognosis for future advancement is offered.Comment: This is a chapter in a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Measurement of the differential cross section for the production of an isolated photon with associated jet in ppbar collisions at sqrt(s)=1.96 TeV

The process ppbar -> photon + jet + X is studied using 1.0 fb^-1 of data collected by the D0 detector at the Fermilab Tevatron ppbar collider at a center-of-mass energy sqrt(s)=1.96 TeV. Photons are reconstructed in the central rapidity region |y_gamma|<1.0 with transverse momenta in the range 30<Pt_gamma<400 GeV while jets are reconstructed in either the central |y_jet|15 GeV. The differential cross section d^3sigma/dPt_gamma dy_gamma dy_jet is measured as a function of Pt_gamma in four regions, differing by the relative orientations of the photon and the jet in rapidity. Ratios between the differential cross sections in each region are also presented. Next-to-leading order QCD predictions using different parameterizations of parton distribution functions and theoretical scale choices are compared to the data. The predictions do not simultaneously describe the measured normalization and Pt_gamma dependence of the cross section in any of the four measured regions.Comment: 13 pages, 10 figure

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale