A5013543313- Cooperative Communication and Network Coding
- Internet Traffic Analysis and Secure E-voting
- Complex Network Analysis Techniques
- Wireless Networks and Protocols
- Mobile Ad Hoc Networks
- Caching and Content Delivery
- Network Security and Intrusion Detection
- Privacy, Security, and Data Protection
- Advanced Malware Detection Techniques
- Human Mobility and Location-Based Analysis
- Network Traffic and Congestion Control
- Advanced Wireless Network Optimization
- Full-Duplex Wireless Communications
- Advanced Graph Neural Networks
- Peer-to-Peer Network Technologies
- Privacy-Preserving Technologies in Data
- Spam and Phishing Detection
- Opportunistic and Delay-Tolerant Networks
- Advanced MIMO Systems Optimization
- Network Packet Processing and Optimization
- Transportation and Mobility Innovations
- Data-Driven Disease Surveillance
- Advanced Clustering Algorithms Research
- Sexuality, Behavior, and Technology
- Cryptography and Data Security
International Hellenic University
2025
University of California, Irvine
2015-2024
Institute for Advanced Architecture of Catalonia
2023
UC Irvine Health
2011-2018
University of California System
2016
Google (Switzerland)
2015
Institute of Electrical and Electronics Engineers
2014
Signal Processing (United States)
2014
Irvine University
2008-2009
Stanford University
1998-2006
With more than 250 million active users, Facebook (FB) is currently one of the most important online social networks. Our goal in this paper to obtain a representative (unbiased) sample users by crawling its graph. In quest, we consider and implement several candidate techniques. Two approaches that are found perform well Metropolis-Hasting random walk (MHRW) re-weighted (RWRW). Both have pros cons, which demonstrate through comparison each other as "ground-truth" (UNI - obtained true...
We analyze IS-IS routing updates from sprint's IP network to characterize failures that affect connectivity. Failures are first classified based on probable causes such as maintenance activities, router-related and optical layer problems. Key temporal spatial characteristics of each class analyzed and, when appropriate, parameterized using well-known distributions. Our results indicate 20% all is due planned activities. Of the unplanned failures, almost 30% shared by multiple links can be...
As the Internet evolves into a ubiquitous communication infrastructure and supports increasingly important services, its dependability in presence of various failures becomes critical. In this paper, we analyze IS-IS routing updates from Sprint IP backbone network to characterize that affect connectivity. Failures are first classified based on patterns observed at IP-layer; some cases, it is possible further infer their probable causes, such as maintenance activities, router-related optical...
Our goal in this paper is to develop a practical framework for obtaining uniform sample of users an online social network (OSN) by crawling its graph. Such allows estimate any user property and some topological properties as well. To end, first, we consider compare several candidate techniques. Two approaches that can produce approximately samples are the Metropolis-Hasting random walk (MHRW) re-weighted (RWRW). Both have pros cons, which demonstrate through comparison each other well...
Video streaming is one of the increasingly popular, as well demanding, applications on smartphones today. In this paper, we consider a group smartphone users, within proximity each other, who are interested in watching same video from Internet at time. The common practice today that user downloads independently using her own cellular connection, which often leads to poor quality.
As the Internet evolves into a ubiquitous communication infrastructure and provides various services including telephony, it has to stand up toll quality standards set by traditional telephone companies. Our objective is assess what extent today's meets this expectation. assessment based on delay loss measurements taken over wide-area backbone networks, considers realistic VoIP scenarios uses measures appropriate for voice. findings indicate that although voice can be adequately provided...
As the Internet evolves into a ubiquitous communication infrastructure and provides various services including telephony, it will be expected to meet quality standards achieved in public switched telephone network. Our objective this paper is assess what extent today's meets expectation. assessment based on delay loss measurements taken over wide-area backbone networks uses subjective voice measures capturing impairments incurred. First, we compile results of studies single model for...
Phishing is an increasingly sophisticated method to steal personal user information using sites that pretend be legitimate. In this paper, we take the following steps identify phishing URLs. First, carefully select lexical features of URLs are resistant obfuscation techniques used by attackers. Second, evaluate classification accuracy when only features, both automatically and hand-selected, vs. additional features. We show sufficient for all practical purposes. Third, thoroughly compare...
Wireless networks suffer from a variety of unique problems such as low throughput, dead spots, and inadequate support for mobility. However, their characteristics the broadcast nature medium, spatial diversity, significant data redundancy, provide opportunities new design principles to address these problems. There has been recent interest in employing network coding wireless networks. This paper explores case unifying paradigm networks, by describing how it addresses issues reliability,...
Breadth First Search (BFS) is a widely used approach for sampling large graphs. However, it has been empirically observed that BFS biased toward high-degree nodes, which may strongly affect the measurement results. In this paper, we quantify and correct degree bias of BFS. First, consider random graph RG(pk) with an arbitrary distribution pk. For model, calculate node expected to be by as function fraction f covered nodes. We also show that, RG(pk), all commonly traversal techniques (BFS,...
Breadth First Search (BFS) and other graph traversal techniques are widely used for measuring large unknown graphs, such as online social networks. It has been empirically observed that incomplete BFS is biased toward high degree nodes. In contrast to more studied sampling techniques, random walks, the bias of not characterized date. this paper, we quantify sampling. particular, calculate node distribution expected be by a function fraction covered nodes, in RG(p <sub...
This paper assesses the potential of ride-sharing for reducing traffic in a city -- based on mobility data extracted from 3G Call Description Records (CDRs), cities Madrid and Barcelona (BCN), OSNs, such as Twitter Foursquare (FSQ), collected New York (NY) Los Angeles (LA). First, we analyze these sets to understand patterns, home work locations, social ties between users. Then, develop an efficient algorithm matching users with similar considering range constraints, including distance. The...
We consider the scenario of broadcasting for realtime applications and loss recovery via instantly decodable network coding. Past work focused on minimizing completion delay, which is not right objective real-time that have strict deadlines. In this work, we are interested in finding a code by maximum number users. First, prove problem NP-Hard general case. Then practical probabilistic scenario, where users i.i.d. probability, packets linear or polynomial case, provide polynomial-time (in...
Smart home devices are vulnerable to passive inference attacks based on network traffic, even in the presence of encryption.In this paper, we present PINGPONG, a tool that can automatically extract packet-level signatures for device events (e.g., light bulb turning ON/OFF) from traffic.We evaluated PINGPONG popular smart ranging plugs and thermostats cameras, voice-activated devices, TVs.We were able to: (1) previously unknown consist simple sequences packet lengths directions; (2) use those...
Mechatronics and Robotics (MaR) have recently gained importance in product development manufacturing settings applications. Therefore, the Center for Space Emerging Technologies (C-SET) has managed an international multi-disciplinary study to present, historically, first Latin American general review of industrial, collaborative, mobile robotics, with support North European researchers institutions. The methodology is developed by considering literature extracted from Scopus, Web Science,...
State-of-the-art techniques for probability sampling of users online social networks (OSNs) are based on random walks a single relation (typically friendship). While powerful, these methods rely the graph being fully connected. Furthermore, mixing time process strongly depends characteristics this graph. In paper, we observe that there often exist other relations between OSN users, such as membership in same group or participation event. We propose to exploit graphs induce, by performing...
Our objective is to sample the node set of a large unknown graph via crawling, accurately estimate given metric interest. We design random walk on an appropriately defined weighted that achieves high efficiency by preferentially crawling those nodes and edges convey greater information regarding target metric. approach begins employing theory stratification find optimal weights, for estimation problem, under independence sampler. While sampling, these weights may be impractical due...
Facebook is one of the most popular Internet sites today. A key feature that arguably contributed to Facebook's unprecedented success its application platform, which enables development third-party social-networking applications. Understanding how these applications are installed and used important for function utility web-based online social networks, e.g. better engineer them and/or design advertising campaigns.
No abstract available.
In this work, we are interested in improving the performance of constructive network coding schemes lossy wireless environments. We propose I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> NC - an approach that combines inter-session and intra-session has two strengths. First, error-correcting capabilities make our scheme resilient to loss. Second, redundancy allows intermediate nodes operate without knowledge decoding buffers their...
We propose AntMonitor - a system for passive monitoring, collection and analysis of fine-grained, large-scale packet measurements from Android devices. is the first its kind that combines following properties: (i) it provides participating users with fine-grained control which data to contribute; (ii) does not require administrative privileges; (iii) supports client-side traffic; (iv) large-scale, semantic-rich traffic. The three properties benefit mobile users, by giving them over their...
Smart speakers collect voice commands, which can be used to infer sensitive information about users. Given the potential for privacy harms, there is a need greater transparency and control over data collected, used, shared by smart speaker platforms as well third party skills supported on them. To bridge this gap, we build framework measure collection, usage, sharing platforms. We apply our Amazon ecosystem. Our results show that parties, including advertising tracking services are unique...
In this paper, we study video streaming over wireless networks with network coding capabilities. We build upon recent work, which demonstrated that can increase throughput a broadcast medium, by mixing packets from different flows into single packet, thus increasing the information content per transmission. Our key insight is that, when transmitted are streams, codes should be selected so as to maximize not only but also quality. propose video-aware opportunistic schemes take account both...
Our goal in this paper is to develop a practical framework for obtaining uniform sample of users an online social network (OSN) by crawling its graph. Such allows estimate any user property and some topological properties as well. To end, first, we consider compare several candidate techniques. Two approaches that can produce approximately samples are the Metropolis-Hasting random walk (MHRW) re-weighted (RWRW). Both have pros cons, which demonstrate through comparison each other well...