Showing papers by "Jon Crowcroft published in 2014"

Human-Data Interaction: The Human Face of the Data-Driven Society

Abstract: The increasing generation and collection of personal data has created a complex ecosystem, often collaborative but sometimes combative, around companies and individuals engaging in the use of these data. We propose that the interactions between these agents warrants a new topic of study: Human-Data Interaction (HDI). In this paper we discuss how HDI sits at the intersection of various disciplines, including computer science, statistics, sociology, psychology and behavioural economics. We expose the challenges that HDI raises, organised into three core themes of legibility, agency and negotiability, and we present the HDI agenda to open up a dialogue amongst interested parties in the personal and big data ecosystems.

Human-Data Interaction: The Human Face of the Data-Driven Society

Abstract: The increasing generation and collection of personal data has created a complex ecosystem, often collaborative but sometimes combative, around companies and individuals engaging in the use of these data. We propose that the interactions between these agents warrants a new topic of study: Human-Data Interaction (HDI). In this paper we discuss how HDI sits at the intersection of various disciplines, including computer science, statistics, sociology, psychology and behavioural economics. We expose the challenges that HDI raises, organised into three core themes of legibility, agency and negotiability, and we present the HDI agenda to open up a dialogue amongst interested parties in the personal and big data ecosystems.

Recommending investors for crowdfunding projects

Abstract: To bring their innovative ideas to market, those embarking in new ventures have to raise money, and, to do so, they have often resorted to banks and venture capitalists. Nowadays, they have an additional option: that of crowdfunding. The name refers to the idea that funds come from a network of people on the Internet who are passionate about supporting others' projects. One of the most popular crowdfunding sites is Kickstarter. In it, creators post descriptions of their projects and advertise them on social media sites (mainly Twitter), while investors look for projects to support. The most common reason for project failure is the inability of founders to connect with a sufficient number of investors, and that is mainly because hitherto there has not been any automatic way of matching creators and investors. We thus set out to propose different ways of recommending investors found on Twitter for specific Kickstarter projects. We do so by conducting hypothesis-driven analyses of pledging behavior and translate the corresponding findings into different recommendation strategies. The best strategy achieves, on average, 84% of accuracy in predicting a list of potential investors' Twitter accounts for any given project. Our findings also produced key insights about the whys and wherefores of investors deciding to support innovative efforts.

Sharing political news: the balancing act of intimacy and socialization in selective exposure

Abstract: One might think that, compared to traditional media, social media sites allow people to choose more freely what to read and what to share, especially for politically oriented news. However, reading and sharing habits originate from deeply ingrained behaviors that might be hard to change. To test the extent to which this is true, we propose a Political News Sharing (PoNS) model that holistically captures four key aspects of social psychology: gratification, selective exposure, socialization, and trust & intimacy. Using real instances of political news sharing in Twitter, we study the predictive power of these features. As one might expect, news sharing heavily depends on what one likes and agrees with (selective exposure). Interestingly, it also depends on the credibility of a news source, i.e., whether the source is a social media friend or a news outlet (trust & intimacy) as well as on the informativeness or the enjoyment of the news article (gratification). Finally, a Twitter user tends to share articles matching his own political leaning but, at times, the user also shares politically opposing articles, if those match the leaning of his followers (socialization). Based on our PoNS model, we build a prototype of a news sharing application that promotes serendipitous political readings along our four dimensions.

Partisan sharing: facebook evidence and societal consequences

Abstract: The hypothesis of selective exposure assumes that people seek out information that supports their views and eschew information that conflicts with their beliefs, and that has negative consequences on our society. Few researchers have recently found counter evidence of selective exposure in social media: users are exposed to politically diverse articles. No work has looked at what happens after exposure, particularly how individuals react to such exposure, though. Users might well be exposed to diverse articles but share only the partisan ones. To test this, we study partisan sharing on Facebook: the tendency for users to predominantly share like-minded news articles and avoid conflicting ones. We verified four main hypotheses. That is, whether partisan sharing: 1) exists at all; 2) changes across individuals (e.g., depending on their interest in politics); 3) changes over time (e.g., around elections); and 4) changes depending on perceived importance of topics. We indeed find strong evidence for partisan sharing. To test whether it has any consequence in the real world, we built a web application for BBC viewers of a popular political program, resulting in a controlled experiment involving more than 70 individuals. Based on what they share and on survey data, we find that partisan sharing has negative consequences: distorted perception of reality. However, we do also find positive aspects of partisan sharing: it is associated with people who are more knowledgeable about politics and engage more with it as they are more likely to vote in the general elections.

What is this place? Inferring place categories through user patterns identification in geo-tagged tweets

Abstract: Online social networks such as Facebook and Twitter have started allowing users to tag their posts with geographical coordinates collected through the GPS interface of users smartphones. While this information is quite useful and already indicative of user behavior, it also lacks some semantics about the type of place the user is (e.g., restaurant, museum, school) which would allow a better understanding of users' patterns. While some location based online social network services (e.g., Foursquare) allow users to tag the places they visit, this is not an automated process but one which requires the user help. In this paper we exploit the dynamics of human activity to associate categories to GPS coordinates of social network posts. We have collected geo-tagged tweets of a large city through Twitter. A supervised learning framework takes the tweets spatial-temporal features and determines human dynamics which we use to infer the place category. Our results over the data show that the prediction framework is able to accurately identify if a place is of a certain category given its user activity patterns. The average accuracy is about 70%, reaching the highest accuracy for work (90%) and educational places (80%). Moreover the framework identifies the category of a place, with an accuracy up to 66%, finding out where people eat and drink, go for entertainment, or work/study.

EpiMap: Towards quantifying contact networks for understanding epidemiology in developing countries

Abstract: We describe the EpiMap project, together with the FluPhone project where we developed the basic technology for EpiMap. In FluPhone, human contact data is collected using mobile phones to record information such as locality and user symptoms for flu or cold. Delay tolerant opportunistic networks were used as a basis for communication. We are extending the technology used in FluPhone to gather information on human interactions within rural communities of developing countries. The collected information will be used to develop improved mathematical models for the spread of infectious diseases such as measles, tuberculosis and pneumococcal diseases. Survey study will aid the understanding of the living conditions in these villages. We introduce the EpiMap vision for a system of opportunistic networks combined with satellite communication, designed to face the challenges posed by weak electricity and communication infrastructures in rural regions of developing countries in Asia, Africa and South America. We aim to use a delay-tolerant small satellite for data transfer between developing countries and Europe ore North America. Data collected through EpiMap can be used to help design more efficient vaccination strategies and equitable control programmes.

Partisan Sharing: Facebook Evidence and Societal Consequences

Abstract: The hypothesis of selective exposure assumes that people seek out information that supports their views and eschew information that conflicts with their beliefs, and that has negative consequences on our society. Few researchers have recently found counter evidence of selective exposure in social media: users are exposed to politically diverse articles. No work has looked at what happens after exposure, particularly how individuals react to such exposure, though. Users might well be exposed to diverse articles but share only the partisan ones. To test this, we study partisan sharing on Facebook: the tendency for users to predominantly share like-minded news articles and avoid conflicting ones. We verified four main hypotheses. That is, whether partisan sharing: 1) exists at all; 2) changes across individuals (e.g., depending on their interest in politics); 3) changes over time (e.g., around elections); and 4) changes depending on perceived importance of topics. We indeed find strong evidence for partisan sharing. To test whether it has any consequence in the real world, we built a web application for BBC viewers of a popular political program, resulting in a controlled experiment involving more than 70 individuals. Based on what they share and on survey data, we find that partisan sharing has negative consequences: distorted perception of reality. However, we do also find positive aspects of partisan sharing: it is associated with people who are more knowledgeable about politics and engage more with it as they are more likely to vote in the general elections.

Convergence of interactive displays with smart mobile devices for effective advertising: A survey

Abstract: The trend of replacing public static signages with digital displays creates opportunities for interactive display systems, which can be used in collaborative workspaces, social gaming platforms and advertising. Based on marketing communication concepts and existing models for consumer behavior, three stages, namely attraction, interaction and conation, are defined in this article to analyze the effectiveness of interactive display advertising. By reviewing various methods and strategies employed by existing systems with attraction, interaction and conation stages, this article concludes that smart mobile devices should be integrated as a component to increase the effectiveness of interactive displays as advertising tools. Future research challenges related to this topic are also discussed.

Improved Structures for Data Collection in Wireless Sensor Networks

Abstract: In this paper we consider the problem of efficient data gathering in sensor networks for arbitrary sensor node deployments. The efficiency of the solution is measured by a number of criteria: total energy consumption, total transport capacity, latency and quality of the transmissions. We present a number of different constructions with various tradeoffs between aforementioned parameters. We provide theoretical performance analysis for our approaches, present their distributed implementation and discuss the different aspects of using each. We show that in many cases our output-sensitive approximation solution performs better than the currently known best results for sensor networks. Our simulation results validate the theoretical findings. © 2014 IEEE.

Policy, Legal and Regulatory Implications of a Europe-Only Cloud

Abstract: There has been on-going discussion regarding the alignment of cloud computing services to a range of European policy objectives. This paper provides an outline of key legal and regulatory aspects arising from recent calls for establishing a Europe-only cloud. After covering the background to such calls, it outlines the policy objectives that may underlie the Europe-only cloud proposals. It then considers some of the legal and regulatory implications of a "Europe-only cloud" or national cloud by analysing what may be meant by "cloud", "Europe", and "only" in this connection.

A Feasibility Study of an In-the-Wild Experimental Public Access WiFi Network

Abstract: Universal Internet access has become critical to modern life, leading to many explorations of approaches to increase its availability. In this paper we report on a study of one such approach, PAWS, that seeks to understand the technical and social constraints of providing Internet access, free at the point of use, by sharing existing broadband subscribers' connections. We elaborate the technical and social context of our deployment, a deprived neighbourhood in a medium-sized British city, and discuss the constraints on and resulting architecture of this system, including the authentication and security mechanisms necessary for a service of this kind. We then report on the use of our deployment over a period of seven months from July 2013 to February 2014, including analyses of the performance and usage of the network. Our data show that PAWS is socially and technically feasible and has the potential to provide Internet access economically to many who are currently digitally disenfranchised. However, doing so requires overcoming numerous challenges, both technical and social.

Space for Internet and Internet for space

Abstract: Space flight and Internet service are technologies that are currently complementary but seem to be on the verge of integration into a new ''space internetworking'' discipline. The authors believe a comprehensive realization of space internetworking technology could dramatically enhance space exploration, augment terrestrial industry and commerce, benefit the economically disadvantaged, and nurture human and civil rights.

Recommending Investors for Crowdfunding Projects

Abstract: To bring their innovative ideas to market, those embarking in new ventures have to raise money, and, to do so, they have often resorted to banks and venture capitalists. Nowadays, they have an additional option: that of crowdfunding. The name refers to the idea that funds come from a network of people on the Internet who are passionate about supporting others' projects. One of the most popular crowdfunding sites is Kickstarter. In it, creators post descriptions of their projects and advertise them on social media sites (mainly Twitter), while investors look for projects to support. The most common reason for project failure is the inability of founders to connect with a sufficient number of investors, and that is mainly because hitherto there has not been any automatic way of matching creators and investors. We thus set out to propose different ways of recommending investors found on Twitter for specific Kickstarter projects. We do so by conducting hypothesis-driven analyses of pledging behavior and translate the corresponding findings into different recommendation strategies. The best strategy achieves, on average, 84% of accuracy in predicting a list of potential investors' Twitter accounts for any given project. Our findings also produced key insights about the whys and wherefores of investors deciding to support innovative efforts.

Towards an Affordable Internet Access for Everyone: The Quest for Enabling Universal Service Commitment (Dagstuhl Seminar 14471).

Abstract: This report document the program and outcomes of the Dagstuhl Seminar 14471 "Towards an Affordable Internet Access for Everyone: The Quest for Enabling Universal Service Commitment". At the seminar, about 27 invited researchers from academia and industry discussed the challenges and solutions for enabling universal and affordable Internet access. This report gives a general overview of the presentations and outcomes of discussions of the seminar.

Poster: SoftOffload: a programmable approach toward collaborative mobile traffic offloading

Abstract: The fast increase of mobile traffic from smartphone-like devices has created a huge pressure for the cellular operators to manage the network infrastructure and resources. Offloading the mobile traffic to alternative networks such as WiFi is sought as a promising direction to solve this problem cost-effectively. According to our study and experimental findings, existing research proposals are lack of concern for the complexity of network deployment and device limitations, which impedes the solution deployment. To overcome such challenge, we propose SoftOffload, a programmable framework for collaborative mobile traffic offloading. SoftOffload takes the advantage of software defined networking (SDN) paradigm in terms of openness and extensibility. We have implemented the first prototype utilising the open source Floodlight platform.

Large-scale distributed Internet-based discovery mechanism for dynamic spectrum allocation

Abstract: Scarcity of frequencies and the demand for more bandwidth is likely to increase the need for devices that utilize the available frequencies more efficiently. Radios must be able to dynamically find other users of the frequency bands and adapt so that they are not interfered, even if they use different radio protocols. As transmitters far away may cause as much interference as a transmitter located nearby, this mechanism can not be based on location alone. Central databases can be used for this purpose, but require expensive infrastructure and planning to scale. In this paper, we propose a decentralized protocol and architecture for discovering radio devices over the Internet. The protocol has low resource requirements, making it suitable for implementation on limited platforms. We evaluate the protocol through simulation in network topologies with up to 2.3 million nodes, including topologies generated from population patterns in Norway. The protocol has also been implemented as proof-of-concept in real Wi-Fi routers.

SNA: Sourceless Network Architecture

Abstract: Why are there source addresses in datagrams? What alternative architecture can one conceive to provide all of the current, and some new functionality, currently dependant on a conflicting set of uses for this field. We illustrate how this can be achieved by re-interpreting the 32-bit field in IPv4 headers to help the Internet solve a range of current and future problems.

LEDBAT performance in sub-packet regimes

Abstract: Wireless Community Networks in the developing world satisfy the basic needs of remote users to information access. However, community networks in developing regions usually rely on low-bandwidth backhaul links that are shared amongst a large user base, driving these links to sub-packet regimes where the per-flow throughput is less than one packet per RTT. TCP performance significantly degrades in such conditions, resulting in severe unfairness and high packet loss rates. In this paper, we investigate the performance of scavenger transport methods, namely LEDBAT and its fair modification fLEDBAT, in the sub-packet regime of shared backhaul links in developing regions. Our intention is to explore the feasibility of using such scavenger transport methods for uploading content over bandwidth constrained backhauls. Our findings show that LEDBAT achieves higher link efficiency and fairness compared to TCP in a variety of sub-packet regime scenarios. When TCP and LEDBAT flows share the same link in the sub-packet regime, LEDBAT flows are more aggressive, consuming more resources than TCP. Therefore, we conclude that a more conservative strategy after consecutive timeouts and shared bottleneck detection mechanisms need to be incorporated into the core LEDBAT algorithm, in order to correctly adjust its congestion window in the sub-packet regime.

Kadupul: Livin' on the Edge with Virtual Currencies and Time-Locked Puzzles

Abstract: Devices connected to the Internet today have a wide range of local communication channels available, such as wireless Wifi, Bluetooth or NFC, as well as wired backhaul. In densely populated areas it is possible to create heterogeneous, multihop communication paths using a combination of these technologies, and often transmit data with lower latency than via a wired Internet connection. However, the potential for sharing meshed wireless radios in this way has never been realised due to the lack of economic incentives to do so on the part of individual nodes. In this paper, we explore how virtual currencies such as Bitcoin might be used to provide an end-to-end incentive scheme to convince forwarding nodes that it is profitable to send packets on via the lowest latency mechanism available. Clients inject a small amount of money to transmit a datagram, and forwarding engines compete to solve a time-locked puzzle that can be claimed by the node that delivers the result in the lowest latency. This approach naturally extends congestion control techniques to a surge pricing model when available bandwidth is low. We conclude by discussing several latency-sensitive applications that would benefit for this, such as video streaming and local augmented reality systems.

Towards an Aordable Internet Access for Everyone: The Quest for Enabling Universal Service Commitment

Abstract: This report document the program and outcomes of the Dagstuhl Seminar 14471 Towards an Aordable Internet Access for Everyone: The Quest for Enabling Universal Service Commitment . At the seminar, about 27 invited researchers from academia and industry discussed the challenges and solutions for enabling universal and aordable Internet access. This report gives a general overview of the presentations and outcomes of discussions of the seminar.

Demo: PhoneLets: offloading the phone off your phone for energy, cost and network load optimization

Abstract: This demo presents how phone functionality can be offloaded from a smartphone over wireless link to a PhoneLet by sharing one SIM card across multiple devices. This can lead to significant cost and network load reductions by decreasing the number of simultaneously connected mobile clients. Furthermore, it can save energy for the mobile user when connected to a powered PhoneLet by offloading phone functionality. It absorbs the energy cost of online presence and inefficient mobile applications' communication patterns, instead providing connectivity for the user over a WiFi link.

Proceedings of the 5th international conference on Future energy systems

Abstract: Welcome to the ACM e-Energy 2014 Conference being held in Cambridge, UK. As Co-Chairs of the Technical Program Committee (TPC), we are delighted to introduce this year's technical program. The program committee accepted 23 full papers selected from 112 submissions in addition to 20 posters / short papers posters and 2 demos. The substantial increase in submissions illustrates the rapid growth of our field. This year's program includes papers covering topics from building energy management to picogrids, from energy optimization in computer systems to electric vehicle charging, from wind energy management to demand response systems and analysis. ACM e-Energy is truly a global conference -- both submitted and accepted papers, posters and demos have authors hailing from over 20 countries. We were fortunate to work with an outstanding technical program committee of 35 members from around the world that brought a diverse range of expertise to the table. Members of the PC were drawn from 4 continents. The hallmark of a high quality conference is a thoughtful and demanding review process that provides valuable feedback to all authors, and ACM e-Energy definitely met that high bar. We are extremely grateful for the hard work, and the very selective and insightful paper reviews, provided by TPC members. In a few cases, we also asked the expertise of external reviewers, who are gratefully acknowledged here. ACM e-Energy used a two-round review process, with a first round of three reviews for each paper. Papers that did not receive a high-confidence review in the first round or received reviews with high variance were assigned additional reviews in a second round of reviewing. After the second round, we initiated online discussions on all submitted papers. The thoughtful asynchronous discussion of papers in advance of the TPC meeting allowed us to discuss 38 papers in depth during an online, day-long TPC meeting that crafted the final program. We believe that the collective efforts of the TPC has created an extremely strong and technically vibrant program that will greatly interest and inspire all attendees while setting a high standard for subsequent editions of the conference.