1,355,413 research outputs found
Link Prediction in Multi-modal Social Networks
No full textOnline social networks like Facebook recommend new friends to users based on an explicit social network that users build by adding each other as friends. The majority of earlier work in link prediction infers new interactions between users by mainly focusing on a single network type. However, users also form several implicit social networks through their daily interactions like commenting on people’s posts or rating similarly the same products. Prior work primarily exploited both explicit and implicit social networks to tackle the group/item recommendation
problem that recommends to users groups to join or items to buy. In this paper, we show that auxiliary information from the useritem network fruitfully combines with the friendship network to enhance friend recommendations. We transform the well-known Katz algorithm to utilize a multi-modal network and provide friend recommendations. We experimentally show that the proposed method is more accurate in recommending friends when compared with two single source path-based algorithms using both synthetic and real data sets
Bilateral functional popliteal artery entrapment in a young athlete
No full textPopliteal artery entrapment syndrome is a frequent cause of intermittent claudication in young patients. We present a case of a bilateral functional entrapment, where static imaging did not demonstrate the occlusion until the patient's feet were placed in forced plantar flexion. A high index of clinical suspicion and dynamic tests with provocative manoeuvres are needed to diagnose this condition.Panagiotis D. Symeonidis, Peter Stavrou and David Kin
Price Competition, Innovation and Profitability: Theory and UK Evidence
No full textThis paper examines the effect of price competition on innovation, market structure and profitability in R&D-intensive industries. The theoretical predictions are tested using UK data on the evolution of competition, concentration, innovation counts and profitability over 1952-1977. The econometric results suggest that the introduction of restrictive practices legislation in the UK had no significant effect on the number of innovations commercialised in previously cartelised R&D-intensive manufacturing industries, while it caused a significant rise in concentration in these industries. In the short run profitability decreased, but in the long run it was restored through the rise in concentration.
Comparing Cournot and Bertrand Equilibria in a Differentiated Duopoly with Product R&D
No full textThis paper compares Bertrand and Cournot equilibria in a differentiated duopoly with substitute goods and product R&D. I find that R&D expenditure, prices and firms� net profits are always higher under quantity competition than under price competition. Furthermore, output, consumer surplus and total welfare are higher in the Bertrand equilibrium than in the Cournot equilibrium if either R&D spillovers are weak or products are sufficiently differentiated. If R&D spillovers are strong and products are not too differentiated, then output, consumer surplus and total welfare are lower in the Bertrand case than in the Cournot case. Thus a key finding of the paper is that there are circumstances where quantity competition can be more beneficial than price competition both for consumers and for firms.
Enhancing the Value of Teacher Education Research
No full textThis book invites us to critically reflect on the value of research in, on and for teacher education. It explores the nature and role of teacher education research and identifies ways to enhance its value for policy and practice. It gathers together studies that deploy a wide range of methodologies, including small-scale practitioner-focused research and large-scale empirical studies, considering the value of both approaches for the development of teacher education research that is meaningful for practice, but also valid and relevant for policy. The studies collected in this book were undertaken in different countries and put forward powerful messages for teacher education research in the 21st century. The ultimate objective is to contribute to the generation of a knowledge base for teacher education, identifying strategies and acknowledging challenges. The various arguments presented here can be utilised by teacher education policymakers, practitioners and researchers wishing to enhance the role of teacher education research in their own countries and contexts. Contributors are: Evi Agostini, Herbert Altrichter, Rinat Arviv, Ilanit Avraham, Tali Berglas-Shapiro, Yvonne Brain, Charalambos Charalambous, Michalis Christodoulou, Ina Cijvat, Gerry Czerniawski, Ricarda Derler, Maria A. Flores, Ulla Fürstenberg, Conor Galvin, Ainat Guberman, Mirva Heikkilä, Tuike Iiskala, Fjolla Kacaniku, Lisa-Maria Lembacher, Joanna Madalińska-Michalak, Aziza Mayo, Jonathan Mendels, Stephanie Mian, Mirjamaija Mikkilä-Erdmann, Hagit Mishkin, Jan Morgenstern, Helma Oolbekkink-Marchand, Nazime Öztürk, Katrin Poom-Valickis, Elena Revyakina, Kari Smith, Marco Snoek, Vasileios Symeonidis, Jullia Tölle, Triin Ulla, Anu Warinowski, Heike Wendt and Cinzia Zadra
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
On the intrinsic AGN emission in the far-infrared/sub-mm
No full textFar-infrared (far-IR)/sub-mm emission linked to AGN-heated dust has been a topic of contention for many years. Results have been diverse and various views have been presented. The empirical AGN SED derived by Symeonidis et al. (2016, hereafter S16) has more far-IR/sub-mm emission than other SEDs in the literature, and thus it is contested by other works which argue that its luminosity in that part of the spectrum is overestimated. Here, I investigate this topic and the concerns raised over the S16 AGN SED. I also examine the differences between the S16 AGN SED and other commonly used empirical AGN SEDs. My findings show that the reasons proposed by other works as to why the S16 AGN SED is not a reasonable representation of AGN emission in the far-IR/sub-mm, do not hold
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Collateral damage of Facebook Apps: an enhanced privacy scoring model
No full textEstablishing friendship relationships on Facebook often entails information sharing which is based on the social trust and implicit contract between users and their friends. In this context, Facebook offers applications (Apps) developed by third party application providers (AppPs), which may grant access to users' personal data via Apps installed by their friends. Such access takes place outside the circle of social trust with the user not being aware whether a friend has installed an App collecting her data. In some cases, one or more AppPs may cluster several Apps and thus gain access to a collection of personal data. As a consequence privacy risks emerge. Previous research has mentioned the need to quantify privacy risks on Online Social Networks (OSNs). Nevertheless, most of the existing works do not focus on the personal data disclosure via Apps. Moreover, the problem of personal data clustering from AppPs has not been studied. In this work we perform a general analysis of the privacy threats stemming from the personal data requested by Apps installed by the user’s friends from a technical and legal point of view. In order to assist users, we propose a model and a privacy scoring formula to calculate the amount of personal data that may be exposed to AppPs. Moreover, we propose algorithms that based on clustering, computes the visibility of each personal data to the AppPs.status: Publishe
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