Experimental Results and Evaluation of SmartBox Stimulation Device in a P2P E-learning System

In this paper, we present the experimental results and evaluation of the SmartBox stimulation device in P2P e-learning system which is based on JXTA-Overlay. We also show the design and implementation of the SmartBox environment that is used for stimulating the learners motivation to increase the learning efficiency. The SmartBox is integrated with our P2P system as a useful tool for monitoring and controlling learners¿ activity. We found by experimental results that the SmartBox is an effective way to increase the learner¿s concentration. We also investigated the relation between learner¿s body movement, concentration, and amount of study. From the experimental results, we conclude that the use of SmartBox is an effective way to stimulate the learners in order to continue studying while maintaining the concentration.

A Secure Mobile-based Authentication System

Financial information is extremely sensitive. Hence, electronic banking must provide a robust system to authenticate its customers and let them access their data remotely. On the other hand, such system must be usable, affordable, and portable.We propose a challengeresponse based one-time password (OTP) scheme that uses symmetriccryptography in combination with a hardware security module. The proposed protocol safeguards passwords from keyloggers and phishing attacks.Besides, this solution provides convenient mobility for users who want to bank online anytime and anywhere, not just from their owntrusted computers.

Concentrations of resveratrol and derivatives in foods and estimation of dietary intake in a Spanish population: European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort

Resveratrol has been shown to have beneficial effects on diseases related to oxidant and/or inflammatory processes and extends the lifespan of simple organisms including rodents. The objective of the present study was to estimate the dietary intake of resveratrol and piceid (R&P) present in foods, and to identify the principal dietary sources of these compounds in the Spanish adult population. For this purpose, a food composition database (FCDB) of R&P in Spanish foods was compiled. The study included 40 685 subjects aged 3564 years from northern and southern regions of Spain who were included in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort. Usual food intake was assessed by personal interviews using a computerised version of a validated diet history method. An FCDB with 160 items was compiled. The estimated median and mean of R&P intake were 100 and 933 mg/d respectively. Approximately, 32% of the population did not consume RΠ The most abundant of the four stilbenes studied was trans-piceid (53·6 %), followed by trans-resveratrol (20·9 %), cis-piceid (19·3 %) and cis-resveratrol (6·2 %). The most important source of R&P was wines (98·4 %) and grape and grape juices (1·6 %), whereas peanuts, pistachios and berries contributed to less than 0·01 %. For this reason the pattern of intake of R&P was similar to the wine pattern. This is the first time that R&P intake has been estimated in a Mediterranean country.

Creació d’un programa informàtic per al monitoratge dels paràmetres de treball i a l’ajut al guiatge d’un tractor agrícola

L’objectiu projecte és desenvolupar un sistema d’ajut al guiatge universal adaptable a qualsevol vehicle que permeti incrementar significativament l’eficiència de les feines a realitzar per la maquinària al camp. El sistema proposat es pot configurar d’acord amb les característiques de la maquinària o de la tasca a realitzar i és capaç de guiar en línia recta i crear paral·leles a la passada recta de referència. Un altre objectiu és millorar el rendiment, la fiabilitat i la usabilitat del programari de monitoratge inicial instal·lat al tractor, com també caracteritzar el receptor GPS AgGPS 332 de Trimble® per a comprovar la precisió de l’aparell. Els resultats obtinguts en la millora del programa de monitoratge són molt satisfactoris a l’haver corregit imprecisions de funcionament que en limitaven l’usabilitat. Els resultats obtinguts en la caracterització del receptor AgGPS 332 permeten valorar millor quin tipus de correcció diferencial és més convenient per a la precisió de treball requerida segons el seu cost de posada en marxa i de funcionament.Els resultats obtinguts en la validació de l’ajut al guiatge, han validat el guiatge a 10 metres vista com un ajut al guiatge equivalent al guiatge manual quan la velocitat de treball és de 5 km/h, el tractorista té referències visuals i no està fatigat. Els resultats obtinguts pels guiatges a 3 i 50 metres no són satisfactoris a 5 km/h. Tanmateix, durant el procés de disseny, la realització dels assajos i durant l’anàlisi de resultats s’han identificat algunes mancances i limitacions i es proposen una sèrie de millores per tal de solucionar-les.

Using narratives to study the impact of social networks on the educational paths of immigrant students

This paper presents the qualitative data collection process aimed at the study of the impactsocial relations and networks have on educational paths of immigrant students. In theframework of a R & D longitudinal study funded by the Ministry of Science and Innovation(2012-2014), the research team tracked the path of 87 immigrant students, from whom only 17successfully achieved the transition through the first and second year of Post-16 Education.A vast range of literature notes that relationships are an important part of migration process andsocial integration analysis, as well as school history in terms of success or failure. Through thefieldwork researchers collect the personal networks of all immigrant students from 3 highschools who were at that time attending last course of compulsory school. The network structureinfluences their social capital and therefore determines the resources, goods and types of supportindividuals can access. All these aspects are influential elements in the configuration anddevelopment of academic trajectories of immigrant students.At the end of the second year of Post-16 Education (two years later), the study captures personalnetworks of these students again, analyses and discusses their evolution and influence on theirpaths through qualitative interviews. Such interviews facilitated the discussion of theirrelationships while providing interesting narratives that are presented in the text. In order to do so, the biographical interpretive narrative method of interviewing is implemented.

Using narratives to study the impact of social networks on the educational paths of immigrant students

This paper presents the qualitative data collection process aimed at the study of the impactsocial relations and networks have on educational paths of immigrant students. In theframework of a R & D longitudinal study funded by the Ministry of Science and Innovation(2012-2014), the research team tracked the path of 87 immigrant students, from whom only 17successfully achieved the transition through the first and second year of Post-16 Education.A vast range of literature notes that relationships are an important part of migration process andsocial integration analysis, as well as school history in terms of success or failure. Through thefieldwork researchers collect the personal networks of all immigrant students from 3 highschools who were at that time attending last course of compulsory school. The network structureinfluences their social capital and therefore determines the resources, goods and types of supportindividuals can access. All these aspects are influential elements in the configuration anddevelopment of academic trajectories of immigrant students.At the end of the second year of Post-16 Education (two years later), the study captures personalnetworks of these students again, analyses and discusses their evolution and influence on theirpaths through qualitative interviews. Such interviews facilitated the discussion of theirrelationships while providing interesting narratives that are presented in the text. In order to do so, the biographical interpretive narrative method of interviewing is implemented.

El discurs regulatiu a l'Aula. El gènere i el discurs regulatiu a la classe de matemàtiques

Aquest article pretén estudiar el discurs regulatiu a l'aula. Concretament, es vol observar si determinades característiques socials en el grup d'alumnes porten a l'ús diferenciat del discurs regulatiu del mestre.

Percolation of spatially constrained Erdos-R enyi networks with degree correlations

Motivated by experiments on activity in neuronal cultures [J. Soriano, M. Rodr ́ıguez Mart́ınez, T. Tlusty, and E. Moses, Proc. Natl. Acad. Sci. 105, 13758 (2008)], we investigate the percolation transition and critical exponents of spatially embedded Erd̋os-Ŕenyi networks with degree correlations. In our model networks, nodes are randomly distributed in a two-dimensional spatial domain, and the connection probability depends on Euclidian link length by a power law as well as on the degrees of linked nodes. Generally, spatial constraints lead to higher percolation thresholds in the sense that more links are needed to achieve global connectivity. However, degree correlations favor or do not favor percolation depending on the connectivity rules. We employ two construction methods to introduce degree correlations. In the first one, nodes stay homogeneously distributed and are connected via a distance- and degree-dependent probability. We observe that assortativity in the resulting network leads to a decrease of the percolation threshold. In the second construction methods, nodes are first spatially segregated depending on their degree and afterwards connected with a distance-dependent probability. In this segregated model, we find a threshold increase that accompanies the rising assortativity. Additionally, when the network is constructed in a disassortative way, we observe that this property has little effect on the percolation transition.

Use of social networks for academic purposes: a case study

Purpose- This paper aims to analyse various aspects of an academic social network: the profile of users, the reasons for its use, its perceived benefits and the use of other social media for scholarly purposes. Design/methodology/approach- The authors examined the profiles of the users of an academic social network. The users were affiliated with 12 universities. The following were recorded for each user: sex, the number of documents uploaded, the number of followers, and the number of people being followed. In addition, a survey was sent to the individuals who had an email address in their profile. Findings- Half of the users of the social network were academics and a third were PhD students. Social sciences scholars accounted for nearly half of all users. Academics used the service to get in touch with other scholars, disseminate research results and follow other scholars. Other widely employed social media included citation indexes, document creation, edition and sharing tools and communication tools. Users complained about the lack of support for the utilisation of these tools. Research limitations/implications- The results are based on a single case study. Originality/value- This study provides new insights on the impact of social media in academic contexts by analysing the user profiles and benefits of a social network service that is specifically targeted at the academic community.

Concentrations of resveratrol and derivatives in foods and estimation of dietary intake in a Spanish population: European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort

Resveratrol has been shown to have beneficial effects on diseases related to oxidant and/or inflammatory processes and extends the lifespan of simple organisms including rodents. The objective of the present study was to estimate the dietary intake of resveratrol and piceid (R&P) present in foods, and to identify the principal dietary sources of these compounds in the Spanish adult population. For this purpose, a food composition database (FCDB) of R&P in Spanish foods was compiled. The study included 40 685 subjects aged 35-64 years from northern and southern regions of Spain who were included in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Spain cohort. Usual food intake was assessed by personal interviews using a computerised version of a validated diet history method. An FCDB with 160 items was compiled. The estimated median and mean of R&P intake were 100 and 933 mg/d respectively. Approximately, 32% of the population did not consume RΠ The most abundant of the four stilbenes studied was trans-piceid (53·6 %), followed by trans-resveratrol (20·9 %), cis-piceid (19·3 %) and cis-resveratrol (6·2 %). The most important source of R&P was wines (98·4 %) and grape and grape juices (1·6 %), whereas peanuts, pistachios and berries contributed to less than 0·01 %. For this reason the pattern of intake of R&P was similar to the wine pattern. This is the first time that R&P intake has been estimated in a Mediterranean country.

Social network extraction and analysis based on multimodal dyadic interaction

Social interactions are a very important component in people"s lives. Social network analysis has become a common technique used to model and quantify the properties of social interactions. In this paper, we propose an integrated framework to explore the characteristics of a social network extracted from multimodal dyadic interactions. For our study, we used a set of videos belonging to New York Times" Blogging Heads opinion blog. The Social Network is represented as an oriented graph, whose directed links are determined by the Influence Model. The links" weights are a measure of the"influence" a person has over the other. The states of the Influence Model encode automatically extracted audio/visual features from our videos using state-of-the art algorithms. Our results are reported in terms of accuracy of audio/visual data fusion for speaker segmentation and centrality measures used to characterize the extracted social network.

Nature of the Epidemic Threshold for the Susceptible-Infected-Susceptible Dynamics in Networks

We develop an analytical approach to the susceptible-infected-susceptible epidemic model that allows us to unravel the true origin of the absence of an epidemic threshold in heterogeneous networks. We find that a delicate balance between the number of high degree nodes in the network and the topological distance between them dictates the existence or absence of such a threshold. In particular, small-world random networks with a degree distribution decaying slower than an exponential have a vanishing epidemic threshold in the thermodynamic limit.

Spectral properties of the Laplacian of multiplex networks.

One of the more challenging tasks in the understanding of dynamical properties of models on top of complex networks is to capture the precise role of multiplex topologies. In a recent paper, Gómez et al. [ Phys. Rev. Lett. 110 028701 (2013)], some of the authors proposed a framework for the study of diffusion processes in such networks. Here, we extend the previous framework to deal with general configurations in several layers of networks and analyze the behavior of the spectrum of the Laplacian of the full multiplex. We derive an interesting decoupling of the problem that allow us to unravel the role played by the interconnections of the multiplex in the dynamical processes on top of them. Capitalizing on this decoupling we perform an asymptotic analysis that allow us to derive analytical expressions for the full spectrum of eigenvalues. This spectrum is used to gain insight into physical phenomena on top of multiplex, specifically, diffusion processes and synchronizability.

Question Waves: A multicast query routing algorithm for social search

This paper describes Question Waves, an algorithm that can be applied to social search protocols, such as Asknext or Sixearch. In this model, the queries are propagated through the social network, with faster propagation through more trustable acquaintances. Question Waves uses local information to make decisions and obtain an answer ranking. With Question Waves, the answers that arrive first are the most likely to be relevant, and we computed the correlation of answer relevance with the order of arrival to demonstrate this result. We obtained correlations equivalent to the heuristics that use global knowledge, such as profile similarity among users or the expertise value of an agent. Because Question Waves is compatible with the social search protocol Asknext, it is possible to stop a search when enough relevant answers have been found; additionally, stopping the search early only introduces a minimal risk of not obtaining the best possible answer. Furthermore, Question Waves does not require a re-ranking algorithm because the results arrive sorted