QoE in Pull Based P2P-TV Systems: Overlay Topology Design Tradeoff

Abstract—This paper presents a systematic performance anal-ysis of pull P2P video streaming systems for live applications, providing guidelines for the design of the overlay topology and the chunk scheduling algorithm. The contribution of the paper is threefold: 1) we propose a realistic simulative model of the system that represents the effects of access bandwidth heterogeneity, latencies, peculiar characteristics of the video, while still guaranteeing good scalability properties; 2) we propose a new latency/bandwidth-aware overlay topology design strategy that improves application layer performance while reducing the underlying transport network stress; 3) we investigate the impact of chunk scheduling algorithms that explicitly exploit properties of encoded video. Results show that our proposal jointly improves the actual Quality of Experience of users and reduces the cost the transport network has to support. I

ТЕОРЕТИЧНА ІНТЕГРАЦІЯ ВЕБ-СЕРВІСІВ ВИЯВЛЕННЯ І КОМПОЗИЦІЇ / D2.4.6. A THEORETICAL INTEGRATION OF WEB SERVICE DISCOVERY AND COMPOSITION (ПЕРЕКЛАД РЕМАРОВИЧ С.)

У даному документі розглядається проблема забезпечення комплексного підходу до автоматичного виявлення і композиції доступних семантичних Веб-сервісів для того, щоб виконати даний запит користувача, вказаний в якості мети композиції.\ud \ud In this document we propose a possible theoretical approach for combining service discovery, functional-level service\ud composition, and process-level service composition. We analyse the challanges in composition of these functionalities (integration of Web service discovery and composition) and propose a theoretical way to solve them.\ud Keyword list: semantic Web service discovery, functional level composition of Web service, process level composition of web service, integration of web service discovery and compositio

Method for detecting web tracking services

Method for detecting web tracking services during browsing activity performed by clients having associated client identifiers, the method comprising the steps of extracting key- value pairs contained into navigation data, looking for one-to-one correspondence between said client identifiers and the values contained in said keys and selecting the keys for which at least a client-value one-to-one correspondence for at least a predetermined number of clients is observed, said keys identifying the associated services as services performing tracking activities

Using Passive Measurements to Demystify Online Trackers

The Internet revolution has led to the rise of trackers—online tracking services that shadow users’ browsing activity. Despite trackers’ pervasiveness, few users install privacy-enhancing plug-ins

Unveiling Web Fingerprinting in the Wild Via Code Mining and Machine Learning

Abstract Fueled by advertising companies' need of accurately tracking users and their online habits, web fingerprinting practice has grown in recent years, with severe implications for users' privacy. In this paper, we design, engineer and evaluate a methodology which combines the analysis of JavaScript code and machine learning for the automatic detection of web fingerprinters. We apply our methodology on a dataset of more than 400, 000 JavaScript files accessed by about 1, 000 volunteers during a one-month long experiment to observe adoption of fingerprinting in a real scenario. We compare approaches based on both static and dynamic code analysis to automatically detect fingerprinters and show they provide different angles complementing each other. This demonstrates that studies based on either static or dynamic code analysis provide partial view on actual fingerprinting usage in the web. To the best of our knowledge we are the first to perform this comparison with respect to fingerprinting. Our approach achieves 94% accuracy in small decision time. With this we spot more than 840 fingerprinting services, of which 695 are unknown to popular tracker blockers. These include new actual trackers as well as services which use fingerprinting for purposes other than tracking, such as anti-fraud and bot recognition

МІНІМАЛІСТИЧНИЙ ПІДХІД ДО СЕМАНТИЧНИХ АНОТАЦІЙ ДЛЯ КОМПОЗИЦІЙ ВЕБ-ПРОЦЕСІВ. ПЕРЕКЛАД СТАТТІ «A MINIMALIST APPROACH TO SEMANTIC ANNOTATIONS FORWEB PROCESSES COMPOSITIONS» (ПЕРЕКЛАД РЕМАРОВИЧ С.)

Семантичні описи Веб-сервісів відкривають шлях до автоматизації їх композиції. Проте, поточні підходи до автоматизованої композиції, які використовують семантику,\ud незважаючи на їх виразну силу, являються важкими у використанні на практиці. Вони вимагають дійсно всеохоплюючих і, зазвичай, великих онтологічних описів процесів, а також досить складних (і часто неефективних) механізмів міркувань. У цій роботі пропонується мінімалістський підхід до семантичної анотації Веб-сервісів,\ud описаних як процеси, такий, що ми можемо виконати обмежене, але ефективне і корисне семантичне міркування для композиції Веб-сервісів на рівні процесу

AUTOMATED COMPOSITION OF WEB SERVICES VIA PLANNING IN ASYNCHRONOUS DOMAINS\ud

The service-oriented paradigm promises a novel degree of interoperability between\ud business processes, and is leading to a major shift in way distributed applications are\ud designed and realized. While novel and more powerful services can be obtained, in such\ud setting, by suitably orchestrating existing ones, manually developing such orchestrations\ud is highly demanding, time-consuming and error-prone. Providing automated service\ud composition tools is therefore essential to reduce the time to market of services, and\ud ultimately to successfully enact the service-oriented approach.\ud In this paper, we show that such tools can be realized based on the adoption and extension\ud of powerful AI planning techniques, taking the “planning via model-checking” approach\ud as a stepping stone. In this respect, this paper summarizes and substantially extends a\ud research line that started early in this decade and has continued till now. Specifically, this\ud work provides three key contributions.\ud First, we describe a novel planning framework for the automated composition of Web\ud services, which can handle services specified and implemented using industrial standard\ud languages for business processes modeling and execution, like ws-bpel. Since these\ud languages describe stateful Web services that rely on asynchronous communication\ud primitives, a distinctive aspect of the presented framework is its ability to model and\ud solve planning problems for asynchronous domains.\ud Second, we formally spell out the theory underlying the framework, and provide algorithms\ud to solve service composition in such framework, proving their correctness and\ud completeness. The presented algorithms significantly extend state-of-the-art techniques\ud for planning under uncertainty, by allowing the combination of asynchronous domains\ud according to behavioral requirements.\ud Third, we provide and discuss an implementation of the approach, and report extensive\ud experimental results which demonstrate its ability to scale up to significant cases for\ud which the manual development of ws-bpel composed services is far from trivial and time\ud consuming

Exploring the cloud from passive measurements: The Amazon AWS case

This paper presents a characterization of Amazon's Web Services (AWS), the most prominent cloud provider that offers computing, storage, and content delivery platforms. Leveraging passive measurements, we explore the EC2, S3 and CloudFront AWS services to unveil their infrastructure, the pervasiveness of content they host, and their traffic allocation policies. Measurements reveal that most of the content residing on EC2 and S3 is served by one Amazon datacenter, located in Virginia, which appears to be the worst performing one for Italian users. This causes traffic to take long and expensive paths in the network. Since no automatic migration and load-balancing policies are offered by AWS among different locations, content is exposed to the risks of outages. The CloudFront CDN, on the contrary, shows much better performance thanks to the effective cache selection policy that serves 98% of the traffic from the nearest available cache. CloudFront exhibits also dynamic load-balancing policies, in contrast to the static allocation of instances on EC2 and S3. Information presented in this paper will be useful for developers aiming at entrusting AWS to deploy their contents, and for researchers willing to improve cloud desig