6 research outputs found

    Data Mining Algorithms for Internet Data: from Transport to Application Layer

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    Nowadays we live in a data-driven world. Advances in data generation, collection and storage technology have enabled organizations to gather data sets of massive size. Data mining is a discipline that blends traditional data analysis methods with sophisticated algorithms to handle the challenges posed by these new types of data sets. The Internet is a complex and dynamic system with new protocols and applications that arise at a constant pace. All these characteristics designate the Internet a valuable and challenging data source and application domain for a research activity, both looking at Transport layer, analyzing network tra c flows, and going up to Application layer, focusing on the ever-growing next generation web services: blogs, micro-blogs, on-line social networks, photo sharing services and many other applications (e.g., Twitter, Facebook, Flickr, etc.). In this thesis work we focus on the study, design and development of novel algorithms and frameworks to support large scale data mining activities over huge and heterogeneous data volumes, with a particular focus on Internet data as data source and targeting network tra c classification, on-line social network analysis, recommendation systems and cloud services and Big data

    Incentive-driven QoS in peer-to-peer overlays

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    A well known problem in peer-to-peer overlays is that no single entity has control over the software, hardware and configuration of peers. Thus, each peer can selfishly adapt its behaviour to maximise its benefit from the overlay. This thesis is concerned with the modelling and design of incentive mechanisms for QoS-overlays: resource allocation protocols that provide strategic peers with participation incentives, while at the same time optimising the performance of the peer-to-peer distribution overlay. The contributions of this thesis are as follows. First, we present PledgeRoute, a novel contribution accounting system that can be used, along with a set of reciprocity policies, as an incentive mechanism to encourage peers to contribute resources even when users are not actively consuming overlay services. This mechanism uses a decentralised credit network, is resilient to sybil attacks, and allows peers to achieve time and space deferred contribution reciprocity. Then, we present a novel, QoS-aware resource allocation model based on Vickrey auctions that uses PledgeRoute as a substrate. It acts as an incentive mechanism by providing efficient overlay construction, while at the same time allocating increasing service quality to those peers that contribute more to the network. The model is then applied to lagsensitive chunk swarming, and some of its properties are explored for different peer delay distributions. When considering QoS overlays deployed over the best-effort Internet, the quality received by a client cannot be adjudicated completely to either its serving peer or the intervening network between them. By drawing parallels between this situation and well-known hidden action situations in microeconomics, we propose a novel scheme to ensure adherence to advertised QoS levels. We then apply it to delay-sensitive chunk distribution overlays and present the optimal contract payments required, along with a method for QoS contract enforcement through reciprocative strategies. We also present a probabilistic model for application-layer delay as a function of the prevailing network conditions. Finally, we address the incentives of managed overlays, and the prediction of their behaviour. We propose two novel models of multihoming managed overlay incentives in which overlays can freely allocate their traffic flows between different ISPs. One is obtained by optimising an overlay utility function with desired properties, while the other is designed for data-driven least-squares fitting of the cross elasticity of demand. This last model is then used to solve for ISP profit maximisation

    Blown to Bits: Your Life, Liberty, and Happiness After the Digital Explosion

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    382 p.Libro ElectrónicoEach of us has been in the computing field for more than 40 years. The book is the product of a lifetime of observing and participating in the changes it has brought. Each of us has been both a teacher and a learner in the field. This book emerged from a general education course we have taught at Harvard, but it is not a textbook. We wrote this book to share what wisdom we have with as many people as we can reach. We try to paint a big picture, with dozens of illuminating anecdotes as the brushstrokes. We aim to entertain you at the same time as we provoke your thinking.Preface Chapter 1 Digital Explosion Why Is It Happening, and What Is at Stake? The Explosion of Bits, and Everything Else The Koans of Bits Good and Ill, Promise and Peril Chapter 2 Naked in the Sunlight Privacy Lost, Privacy Abandoned 1984 Is Here, and We Like It Footprints and Fingerprints Why We Lost Our Privacy, or Gave It Away Little Brother Is Watching Big Brother, Abroad and in the U.S. Technology Change and Lifestyle Change Beyond Privacy Chapter 3 Ghosts in the Machine Secrets and Surprises of Electronic Documents What You See Is Not What the Computer Knows Representation, Reality, and Illusion Hiding Information in Images The Scary Secrets of Old Disks Chapter 4 Needles in the Haystack Google and Other Brokers in the Bits Bazaar Found After Seventy Years The Library and the Bazaar The Fall of Hierarchy It Matters How It Works Who Pays, and for What? Search Is Power You Searched for WHAT? Tracking Searches Regulating or Replacing the Brokers Chapter 5 Secret Bits How Codes Became Unbreakable Encryption in the Hands of Terrorists, and Everyone Else Historical Cryptography Lessons for the Internet Age Secrecy Changes Forever Cryptography for Everyone Cryptography Unsettled Chapter 6 Balance Toppled Who Owns the Bits? Automated Crimes—Automated Justice NET Act Makes Sharing a Crime The Peer-to-Peer Upheaval Sharing Goes Decentralized Authorized Use Only Forbidden Technology Copyright Koyaanisqatsi: Life Out of Balance The Limits of Property Chapter 7 You Can’t Say That on the Internet Guarding the Frontiers of Digital Expression Do You Know Where Your Child Is on the Web Tonight? Metaphors for Something Unlike Anything Else Publisher or Distributor? Neither Liberty nor Security The Nastiest Place on Earth The Most Participatory Form of Mass Speech Protecting Good Samaritans—and a Few Bad Ones Laws of Unintended Consequences Can the Internet Be Like a Magazine Store? Let Your Fingers Do the Stalking Like an Annoying Telephone Call? Digital Protection, Digital Censorship—and Self-Censorship Chapter 8 Bits in the Air Old Metaphors, New Technologies, and Free Speech Censoring the President How Broadcasting Became Regulated The Path to Spectrum Deregulation What Does the Future Hold for Radio? Conclusion After the Explosion Bits Lighting Up the World A Few Bits in Conclusion Appendix The Internet as System and Spirit The Internet as a Communication System The Internet Spirit Endnotes Inde

    Inter-domain traffic management in and evolving Internet peering eco-system

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    Operators of the Autonomous Systems (ASes) composing the Internet must deal with constant traffic growth, while striving to reduce the overall cost-per-bit and keep an acceptable quality of service. These challenges have motivated ASes to evolve their infrastructure from basic interconnectivity strategies, using a couple transit providers and a few settlement-free peers, to employ geographical scoped transit services (e.g. partial transit) and multiplying their peering efforts. Internet Exchange Points (IXPs), facilities allowing the establishment of sessions to multiple networks using the same infrastructure, have hence become central entities of the Internet. Although the benefits of a diverse interconnection strategy are manifold, it also encumbers the inter-domain Traffic Engineering process and potentially increases the effects of incompatible interests with neighboring ASes. To efficiently manage the inter-domain traffic under such challenges, operators should rely on monitoring systems and computer supported decisions. This thesis explores the IXP-centric inter-domain environment, the managing obstacles arising from it, and proposes mechanisms for operators to tackle them. The thesis is divided in two parts. The first part examines and measures the global characteristics of the inter-domain ecosystem. We characterize several IXPs around the world, comparing them in terms of their number of members and the properties of the traffic they exchange. After highlighting the problems arising from the member overlapping among IXPs, we introduce remote peering, an interconnection service that facilitates the connection to multiple IXPs. We describe this service and measure its adoption in the Internet. In the second part of the thesis, we take the position of the network operators. We detail the challenges surrounding the control of inter-domain traffic, and introduce an operational framework aimed at facilitating its management. Subsequently, we examine methods that peering coordinators and network engineers can use to plan their infrastructure investments, by quantifying the benefits of new interconnections. Finally, we delve into the effects of conflicting business objectives among ASes. These conflicts can result in traffic distributions that violate the (business) interests of one or more ASes. We describe these interest violations, differentiating their impact on the ingress and egress traffic of a single AS. Furthermore, we develop a warning system that operators can use to detect and rank them. We test our warning system using data from two real networks, where we discover a large number of interest violations. We thus stress the need for operators to identify the ones having a larger impact on their network.This work has been supported by IMDEA Networks Institute.Programa Oficial de Doctorado en Ingeniería TelemáticaPresidente: Jordi Domingo-Pascual.- Secretario: Francisco Valera Pintor.- Vocal: Víctor Lópe

    Animating the Ethical Demand:Exploring user dispositions in industry innovation cases through animation-based sketching

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    This paper addresses the challenge of attaining ethical user stances during the design process of products and services and proposes animation-based sketching as a design method, which supports elaborating and examining different ethical stances towards the user. The discussion is qualified by an empirical study of Responsible Research and Innovation (RRI) in a Triple Helix constellation. Using a three-week long innovation workshop, UCrAc, involving 16 Danish companies and organisations and 142 students as empirical data, we discuss how animation-based sketching can explore not yet existing user dispositions, as well as create an incentive for ethical conduct in development and innovation processes. The ethical fulcrum evolves around Løgstrup's Ethical Demand and his notion of spontaneous life manifestations. From this, three ethical stances are developed; apathy, sympathy and empathy. By exploring both apathetic and sympathetic views, the ethical reflections are more nuanced as a result of actually seeing the user experience simulated through different user dispositions. Exploring the three ethical stances by visualising real use cases with the technologies simulated as already being implemented makes the life manifestations of the users in context visible. We present and discuss how animation-based sketching can support the elaboration and examination of different ethical stances towards the user in the product and service development process. Finally we present a framework for creating narrative representations of emerging technology use cases, which invite to reflection upon the ethics of the user experience.</jats:p
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