Exploiting Social Networks for Recommendation in Online Image Sharing Systems

This thesis aims to demonstrate the distinct and so far little explored value of knowledge derived from social interaction data within large web-scale image sharing systems like Flickr, Picasa Web, Facebook and others for image recommendation. I have shown how such systems can be significantly improved through personalisation that takes into account the social context of users by modelling their interactions by mining data, building and evaluating systems that incorporate this information. These improvements allow users to search and browse large online image collections more quickly and to find results that more accurately match their personal information needs when compared to existing methods. Traditional information retrieval and recommendation datasets are contrived to provide stable baselines for researchers to compare against but they rarely accurately reflect the media systems users tend to encounter online. The online photo sharing site Flickr provides rich and varied data that can be used by researchers to analyse and understand users’ interactions with images and with each other. I analyse such data by modelling the connections between users as multigraphs and exploiting the resultant topologies to produce features that can be used to train recommender systems based on machine learnt classifiers. The core contributions of this work include insight into the nature of very large-scale on- line photo collections and the communities that form around them, as well as the dynamic nature of the interactions users have with their media. I do this through the rigorous evaluation of both a probabilistic tag recommendation system and a machine learnt classifier trained to mimic user decisions regarding image preference. These implementations focus on treating the user as both a unique individual and as a member of potentially many explicit and implicit communities. I also explore the validity of the Flickr ‘Favourite’ feedback label as proxy for user preference, which is particularly important when considering other analogous media systems to which my findings transfer. My conclusions highlight how vital both social context information and the understanding of user behaviour are for online image sharing systems. In the field of information retrieval the diverse nature of users is often forgotten in the hunt for increases in esoteric performance metrics. This thesis places them back at the centre of the problem of multimedia information retrieval and shows how their variety and uniqueness are valuable traits that can be exploited to augment and improve the experience of browsing and searching shared online image collections

El diseño de materiales para el desarrollo de la Competencia Intercultural Comunicativa en el aula de ILE

This present paper explores, analyses, proves and tries to provide a solution to the patent need for Intercultural Communicative Competence Development that a group of 56 students of first year of post-compulsory education portray. Thus, trough the convergence of different fields of study ranging from Intercultural Communicative Competence, Communicative Language Teaching and Second Language Acquisition, this document presents a needs analysis and a subsequent pedagogical intervention proposal that aims to erode the existing prejudices in young students today and to promote intercultural interaction by raising their awareness and by providing them with the necessary tools to reflect on themselves and on the others in a more tolerant, thoughtful and communicative way. The pedagogical intervention proposal has been nominated as “Ten Mini-Pills for Intercultural Communicative Competence Development” in which students are faced with concrete examples of the elements that shape other cultures so as for them to be able to deconstruct their cosmovision and thus integrate the reality of others. The “Ten Mini-Pills for Intercultural Communicative Competence Development” have been designed in the light of adaptability and easy implementation, so as for them to not only meet the needs of this concrete group of students but of as many as possible. <br /

Exploring human mobility patterns based on geotagged Flickr photos

Predicting human mobility behaviour has long been a topic of scientific interest. Such studies generally rely on tracking human movements through a range of data collection methodologies such as using GPS trackers, cellular network data etc. Some of this data may be confidential or hard to acquire. This thesis explores if existing publicly available data on online photo sharing platforms can be used to determine human mobility patterns with reasonable accuracy. We choose the Flickr website as the data collection medium as it has an extensive user base actively sharing photos many of which, have geo tags embedded in them which are preserved by Flickr. Our analysis reveals that while the data from Flickr is sparse and discontinuous making it unsuitable for reliable mobility prediction, typical human mobility trends based on time of day, day of week and month of the year can still be extracted. Such interesting patterns could be potentially used in traffic engineering domains or for user profiling purposes. More specifically, we describe how to obtain a subset of frequent active users and their information from Flickr, and the sliding window mechanism to filter the active periods of the users. Later we explain the various statistical methods applied on the filtered subset of data to identify the categories in which users could be classified, mainly short distance travellers and long distance travellers. The short distance travellers are considered for mobility trends prediction

Social software for music

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 200

Can we predict a riot? Disruptive event detection using Twitter

In recent years, there has been increased interest in real-world event detection using publicly accessible data made available through Internet technology such as Twitter, Facebook, and YouTube. In these highly interactive systems, the general public are able to post real-time reactions to “real world” events, thereby acting as social sensors of terrestrial activity. Automatically detecting and categorizing events, particularly small-scale incidents, using streamed data is a non-trivial task but would be of high value to public safety organisations such as local police, who need to respond accordingly. To address this challenge, we present an end-to-end integrated event detection framework that comprises five main components: data collection, pre-processing, classification, online clustering, and summarization. The integration between classification and clustering enables events to be detected, as well as related smaller-scale “disruptive events,” smaller incidents that threaten social safety and security or could disrupt social order. We present an evaluation of the effectiveness of detecting events using a variety of features derived from Twitter posts, namely temporal, spatial, and textual content. We evaluate our framework on a large-scale, real-world dataset from Twitter. Furthermore, we apply our event detection system to a large corpus of tweets posted during the August 2011 riots in England. We use ground-truth data based on intelligence gathered by the London Metropolitan Police Service, which provides a record of actual terrestrial events and incidents during the riots, and show that our system can perform as well as terrestrial sources, and even better in some cases

Integrating Haptic Feedback into Mobile Location Based Services

Haptics is a feedback technology that takes advantage of the human sense of touch by applying forces, vibrations, and/or motions to a haptic-enabled device such as a mobile phone. Historically, human-computer interaction has been visual - text and images on the screen. Haptic feedback can be an important additional method especially in Mobile Location Based Services such as knowledge discovery, pedestrian navigation and notification systems. A knowledge discovery system called the Haptic GeoWand is a low interaction system that allows users to query geo-tagged data around them by using a point-and-scan technique with their mobile device. Haptic Pedestrian is a navigation system for walkers. Four prototypes have been developed classified according to the user’s guidance requirements, the user type (based on spatial skills), and overall system complexity. Haptic Transit is a notification system that provides spatial information to the users of public transport. In all these systems, haptic feedback is used to convey information about location, orientation, density and distance by use of the vibration alarm with varying frequencies and patterns to help understand the physical environment. Trials elicited positive responses from the users who see benefit in being provided with a “heads up” approach to mobile navigation. Results from a memory recall test show that the users of haptic feedback for navigation had better memory recall of the region traversed than the users of landmark images. Haptics integrated into a multi-modal navigation system provides more usable, less distracting but more effective interaction than conventional systems. Enhancements to the current work could include integration of contextual information, detailed large-scale user trials and the exploration of using haptics within confined indoor spaces

Corpses, Guns, Penises and Private Military and Security Corporations

The purpose of this dissertation is to reconceptualise how the work of private military and security companies (PMSCs) comes to matter. The overarching argument is: PMSC work is made to matter through an entanglement of ‘things’, agencies and processes that are not exclusively bound to the needs or desires of clients, regulators or PMSCs themselves. The word matter is used in a dual-sense of becoming meaningful and becoming materialized. I advance the possibility that PMSC work comes to matter through multifaceted enactments of human, formerly human (e.g. the dead), not exclusively human (e.g. penises), and non-human (e.g. guns) agencies. Simultaneously I perform a thorough accounting of the four processes – privatizing, militarizing, securing and commercializing– that overdetermine what this works means to global relations of security. Constituting the (meta-)theoretical apparatus of this dissertation is an entanglement of post-human, queer and feminist considerations of materiality, agency and agents, normativity and accountability. By privileging a post-human, queer and feminist analysis I produce an uncommon understanding of PMSC work that reconfigures the boundaries of what actually matters amongst global relations of security. I also offer an incisive critique of the political-economic processes that overdetermine the meaning of the work that PMSCs perform