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Niklas Carlsson

Associate Professor (Swedish: Docent+universitetslektor)
Linköping University, Dept of Comp & Info Science (IDA)


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Welcome!

I am an Associate Professor (Swedish: docent and universitetslektor) in Computer Science (IDA) at Linkoping University, Sweden. My general research interests are design, modeling, and performance evaluation of distributed systems and networks.

News and updates:


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Dec. 2016: Congrats to Rahul Hiran, defending his PhD thesis
Rahul Hiran successfully defended his PhD thesis titled "Collaborative Network Security: Targeting Wide-area Routing and Edge-network Attacks" on Dec. 2. In honor of his PhD, we can look back at much of the exciting work that she did in the area of wide-area BGP routing security and the design of collaborative security mechanisms. In particular, his thesis covers a characterization of the China Telecom incident (published at PAM 2013), a distributed alliance framework for collaborative BGP monitoring and prefix-based security, called PrefiSec (ACM WISCS @ CCS 2014), the CrowdSec paper (IEEE CNS 2015), and an evaluation of the scale, size, and locality aspects of a wide range of collaborative BGP security mechanisms (IFIP Networking 2016).
Further reading: Defense slides, Rahul's website, Research description (with paper links)

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Nov. 2016: Keynote at IEEE WNM @ LCN
Give keynote about our work on YouTube popularity dynamics and third-party authentication, also including some exciting results from our latest IEEE TPDS paper in which we model and analyze the impact of "one-timers" (or "one-hit wonders") on caching.
Further reading: Talk slides,

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Nov. 2016: Third-party tracking characterization and user action identification in HTTPS traffic @ IEEE LCN
Do you know how tracked you are when surfing the Internet? And, do you think using HTTPS helps protect you from tracking? Our two IEEE LCN papers provides some insights. First, in our paper "Third-party Tracking on the Web: A Swedish Perspective" we characterize the third-party tracking landscape and provides insights into how much tracking coverage different organizations and tracking services may have. We also show that sites implementing HTTPS may in fact use more tracking than other sites. In our second paper, "Identifying User Actions From HTTP(S) Traffic", we instead look at the tracking that an operator may do. Here, we implement and test timing-based classifiers that identifies user actions in HTTP(S) traffic. We also present a rigorous and automated evaluation framework which we use for the evaluation. The classifiers can operate at the HTTP level, on a per-flow level, or using packet-level information. Among other things, this papers therefore provides insights into how much information about user activity can be gained also using network data. This quetsion is motivated by more and more traffic being encrypted and delivered over HTTPS.
Further reading: Tracking paper, User action identification paper

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Nov. 2016: Congrats to Vengat who successfully defended his Licentiate
Vengatanathan Krishnamoorthi successfully defended his Licentiate thesis titled "Efficient and Adaptive Content Delivery of Linear and Interactive Branched Videos" on Nov. 4. The thesis includes highlights from his papers presented in IEEE MASCOTS 2013 (pdf), ACM SIGCOMM workshop FhMN 2013 (pdf), and ACM Multimedia 2014 (pdf).
Further reading: Defense slides, Vengat's website, Research description,

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Nov. 2016: Grant approved from Swedish Research Council (VR)
My VR grant on "Optimized Protocols for Delivering Tomorrow's Streaming Services" was approved (2017-2020). More news on this project to come.
Further reading: Example papers at ACM Multimedia 2014, ACM Multimedia 2015, ACM SIGCOMM workshop FhMN 2013, and IEEE TPDS.

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Sept. 2016: Exciting news and congrats to Anna Vapen, our latest PhD graduate
Anna Vapen successfully defended her PhD thesis titled "Web Authentication using Third-Parties in Untrusted Environments" on Sept 30. In honor of her PhD, we can look back at much of the exciting work that she did in the area of third-party authentication, including her conference papers in PAM 2014 (pdf), IFIP SEC 2015 (pdf), ACM CODASPY 2015 (pdf), UEOP@NDSS 2016 (pdf), and 2016 magazine article in IEEE Internet Computing (pdf).
Further reading: Defense slides, Anna's website, Research description

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Sept. 2016: One-timer paper accepted to IEEE TPDS
Our paper "Ephemeral Content Popularity at the Edge and Implications for On-Demand Caching" is accepted to IEEE Transactions on Parallel and Distributed Systems (IEEE TPDS). This paper considers the problem that the ephemeral content popularity seen with many content delivery applications can make indiscriminate on-demand caching in edge networks highly inefficient, since many of the content items that are added to the cache will not be requested again from that network. We call these items one-timers (or one-hit wonders), design more selective edge-network caching policies, and demonstrate the need for such policies through an analysis of a dataset recording YouTube video requests from users on an edge network over a 20-month period. We also develop a novel workload modelling approach for such applications, apply it to study the performance of alternative edge caching policies, including indiscriminate caching and cache on k-th request for different k, before finally quantifying and exploring the potential room for improvement from use of other possible predictors of further requests.
Further reading: paper

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May. 2016: Does size matter? Scale? Locality?
Our IFIP Networking paper answers the classic question if size matters ... and if locality and scale matter, for that matter! More specifically, we use measurement data to evaluate some promising, previously proposed techniques for preventing and detecting routing attacks in cases where the techniques are implemented by different subsets of Autonomous Systems (AS), and answer questions regarding which ASes need to collaborate, the importance of the locality and size of the participating ASes, and how many ASes are needed to achieve good efficiency when different subsets of ASes collaborate. Our results and answers to the above questions help determine the effectiveness of potential incremental rollouts of different classes of detection/prevention techniques.
Further reading: paper

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Mar. 2016: eeeBond (or "Tripple-e Bond") paper runner-up for best research paper award at ICPE 2016
The paper "Optimized eeeBond: Energy Efficiency with non-Proportional Router Network Interfaces" was presented during a special paper award candidate session, but unfortunately fell short to a paper by Giuliano and colleagues. Congrats Weikun, Giuliano, Ajay, and Manoj!
Further reading: paper

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Mar. 2016: IEEE Internet Computing article online
Our article "A Look at the Third-Party Identity Management Landscape" is now published. In this article, we provide an overview of third-party identity management's current landscape. Using datasets collected through manual identification and large-scale crawling, we answer questions related to which sites act as Relaying Parties (RPs), which sites are the most successful Identify Providers (IDPs), and how different classes of RPs select their IDPs.
Further reading: article on publisher site

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Feb. 2016: SIGMETRICS TPC meeting and workshop
Attending the SIGMETRICS/Performance TPC meeting at Columbia University, NY. The slides for my workshop presentation can be found here. The conference will take place in Antibes Juan-les-Pins, France, in June 2016.
Further reading:
workshop slides, conference website

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Jan. 2016: Revenue-maximizing and Truthful Online Auctions for Dynamic Spectrum Access
Nice start to the New Year! Two papers at IEEE/IFIP WONS 2016, including our work on revenue-maximizing and truthful online actions for secondary spectrum.
Further reading: paper

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Jan. 2016: Bredbandskollen project and crowd-sourced network measurements
Our paper on using crowd-sourced network measurements for performance prediction (e.g., using performance maps) will be presented at IEEE/IFIP WONS 2016. In this work we use a large-scale crowd-sourced dataset from Bredbandskollen, Sweden's primary speedtest service, to evaluate the prediction accuracy and achievable performance improvements with such data.
Further reading: paper

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Sept. 2015: HBO to make "interactive branched video" in "choose your own adventure" project with Steven Soderbergh
It looks like interactive and personalized video streaming may be taking another big step towards going mainstream. Based on recent news it appears that Steven Soderbergh is making an interactive "choose your own adventure" project for HBO. In the past other big companies such as BBC have used "interactive branched videos" for interactive news such as Quantum thinking: Cats to computers. Other creative examples can be found on sites such as Interlude. Going mainstream is expected to provide many new use cases for the HTTP-based Adaptive Streaming (HAS) system proposed and optimized in our ACM FhMN@SIGCOMM 2013 best-paper-award paper and ACM Multimedia 2014 paper, respectively. Alternative optimized solutions (for the broadcast or multicast domains) are provided in our IEEE Transactions on Multimedia paper (from 2008).

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July 2015: Paper accepted at ACM Multimedia 2015
Internet users are increasingly impatient! In our paper "Bandwidth-aware Prefetching for Proactive Multi-video Preloading and Improved HAS Performance", which was accepted to Proc. ACM Multimedia 2015, we take a big step towards removing stalls and improving the overall video streaming experience of users. The paper includes the design, implementation, and evaluation of an HTTP-based Adaptive Streaming (HAS) solution that provides careful prefetching and buffer management, which reduces the startup times of alternative videos that the user may want to watch next by an order of magnitude, while simultaneously improving the playback quality of the streaming video itself.
Further reading: paper

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July 2015: Paper accepted at IEEE CNS 2015
Our paper "Crowd-based Detection of Routing Anomalies on the Internet" was accepted to IEEE Conference on Communications and Network Security (IEEE CNS) 2015.
Further reading: paper

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June 2015: ACM SIGMETRICS election results
I am proud and honored to have been elected to be the ACM SIGMETRICS Secretary-Treasurer, starting on July 1, 2015.
Results: https://www.acm.org/sigs/elections/sigmetrics-2015-results,

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June 2015: Available positions as Senior Lecturer
We are looking for new co-workers. Up-to two Senior Lecturer positions in Systems Software and Networking, at the Department of Computer and Information Science, Linköping University, Sweden.
More information: See vacancies,

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Mar. 2015: Outstanding poster award at ACM CODASPY
Congratulations Anna! Our poster "Information Sharing and User Privacy in the Third-party Identity Management Landscape" received an outstanding poster award at ACM CODASPY 2015. The same week, the full paper (with the same title) is also accepted at IFIP SEC 2015.
Further reading: ACM CODASPY poster paper, IFIP SEC paper

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2015: TPC-chair IEEE MASCOTS 2015
I am TPC-chair with Giuliano Casale (Imperial College London, UK) for IEEE MASCOTS 2015, located in Atlanta, GA, October 5-7, 2015. We have a very strong TPC and are looking forward to many interesting paper submission (deadline March 30, 2015).
Conference website: IEEE MASCOTS 2015

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Dec. 2014: Positive "Green Domino" Incentive Effects
Internet traffic is routed through a sequence of connected routers. Clearly, the actions taken by one router can affect both the performance and the potential energy savings that neighboring routers can achieve. With high energy costs, operators increasingly often use "green" (or energy saving) adaptive link rate (ALR) policies at their routers to save money. The implementation of such policies therefore raises questions such as what impact one router implementing these policies may have on the potential energy savings that other routers can achieve. In our recent ACM/SPEC ICPE 2015 paper, "Green Domino Incentives: Impact of Energy-aware Adaptive Link Rate Policies in Routers", we investigate this and other related questions, and show that implementation of these policies can have positive cascading ("green domino") incentive effects.
Further reading: paper

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July 2014: "Branched video" paper accepted at ACM Multimedia 2014
Interactive branched video (sometimes also called nonlinear or multipath streaming) allows users to select their own paths through the video and provides creative content designers with great personalization opportunities. In our paper "Quality-adaptive Prefetching for Interactive Branched Video using HTTP-based Adaptive Streaming", accepted to Proc. ACM Multimedia 2014, we show how the playback quality for branched video can be optimized using branch-aware prefetching policies, while ensuring ensure seamless playback without playback interruptions.
Further reading: paper

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June 2014: "Geographically distributed clouds" paper accepted at IFIP Performance 2014
Our paper "Caching and Optimized Request Routing in Cloud-based Content Delivery Systems", which considers caching and request routing optimization in geographically distributed clouds, is accepted to Proc. IFIP Performance 2014.
Further reading: please see publications

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Apr/May 2014: "Dynamic content allocation" paper at IEEE INFOCOM 2014
Present our paper "Dynamic Content Allocation for Cloud-assisted Service of Periodic Workloads" at Proc. IEEE INFOCOM 2014.
Further reading: paper

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Apr. 2014: Research trip to Canada (UofS and UofC)

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Mar. 2014: "Scalable Multicore" paper in CCPE
Our paper "Characterizing the Scalability of a Web Application on a Multi-core Server" appears in Concurrency and Computation Practice and Experience (CCPE), Wiley. This paper should be of interest to anybody that wants to get the most out of their multicore system.
See publications for paper and details.

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Mar. 2014: "Third-party Identity Management" paper at PAM
Anna presented our paper "Third-party Identity Management Usage on the Web" at Proc. PAM 2014.
Further reading: paper

Oct. 2013: PhD defence in the Netherlands
External commitee member at Adele Lu Jia's PhD defence, Delft University of Technology, Delft, the Netherlands.

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Aug 2013: Best Paper Award at ACM FhMN
Our paper "Empowering the Creative User: Personalized HTTP-based Adaptive Streaming of Multi-path Nonlinear Video" is given the Best Paper Award in the ACM SIGCOMM Workshop on Future Human-Centric Multimedia Networking (FhMN) 2013 and will appear in a special issue of ACM CCR.
Further reading: paper


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Aug. 2013: Three papers accepted and presented at IEEE MASCOTS 2013
Our papers "Helping Hand or Hidden Hurdle: Proxy-assisted HTTP-based Adaptive Streaming Performance", "On Zipf Models for Probabilistic Piece Selection in P2P Stored Media Streaming", and "Revisiting Popularity Characterization and Modeling for User-generated Videos" were all accepted and presented at IEEE MASCOTS 2013.
See publications for papers and details.


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July 2013: The right to be forgotten
You have likely heard of the many people suffering from photos they wish never would have been posted online, or maybe even seen the much talked about suicide note video made by a girl that could not remove an online photo she wanted forgotten. Our paper "A Peer-to-Peer Agent Community for Digital Oblivion in Online Social Networks" presents a solution to help these people towards the right to be forgotten. (See publications for details)


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June 2013: ACM Greenmetrics 2013
For the fifth straight year I am co-organizing the GreenMetrics workshop collocated and sponsored by ACM SIGMETRICS. The workshop takes place at at CMU, Pittsburgh, PA, on June 17. We will have a great program with very good keynote speakers.
Further reading: workshop page


June 2013: PhD defence in Norway
External examiner at Tomas Kupka's PhD defence, Simula and University of Oslo, Norway.

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May 2013: Research visits to NICTA (Australia) and University of Auckland (New Zeeland)


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Mar 2013: Multicore paper accepted and presented at ACM/SPEC ICPE
Joint work "Improving the Scalability of a Multi-core Web Server", with Raoufehsadat Hashemian (University of Calgary), Diwakar Krishnamurthy (University of Calgary), and Martin Arlitt (HP Labs) presented at ACM/SPEC International Conference on Performance Engineering (ICPE).
Further reading: paper


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Mar. 2013: Accepted PAM paper on the much debated China Telecom Incident
Traffic interception using route hijacks is a huge threat to individuals, organizations, and entire countries. Using route hijacks miscreants can intentionally misdirect Internet traffic to take paths through their networks. With much sensitive information being carried over the Internet, this emerging global problem is becoming increasingly important to understand and address. In our paper "Characterizing Large-scale Routing Anomalies: A Case Study of the China Telecom Incident", which appeared in Proc. Passive and Active Measurement Conference (PAM), March 2013, we characterize and analyze a much debated such event. This work was also recently featured in a Citizen Lab blog post.
Further reading: paper, Citizen Lab blog


Feb 2013: First two community highlights features in IEEE STC-SC newsletter
Dr. Canturk Isci (IBM) and I have been working on a community highlight feature for the IEEE STCSC monthly newsletter. Our first two features highlight the research of Professor Magaret Martonosi (Princeton University) and Dr. Partha Ranganathan (Hewlett Packard Labs).
Further reading February issue


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Feb. 2013: Docent lecture
Exciting times, as I present my docent lecture and gets upgraded to Associate Professor (docent).


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Feb. 2013: Dynamic swarm management paper accepted and published in IEEE/ACM ToN
Our paper "Centralized and Distributed Protocols for Tracker-based Dynamic Swarm Management" appears in IEEE/ACM Transactions on Networking (ToN). (See publications for details)


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Jan/Feb. 2013: Power-law paper accepted and published in IEEE Network
Our paper "A Tale of the Tails: Power-laws in Internet Measurements" in which we look at power-laws in Internet measurements is published in IEEE Network.
(See publications for details)


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Jan/Feb. 2013: PC Meeting ACM SIGMETRICS 2013
I recently attended the PC meeting in Pittsburgh, PA. The conference will appear at CMU in June 2013.
Further reading: conference website


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Dec. 2012: "Scalable Anonymity Protocols" article published in Performance Evaluation
Overhead and scalability is an issue for many existing anonymity protocols, including Tor. Our most recent Performance Evaluation paper "Performance Modeling of Anonymity Protocols" presents the design and analysis of scalable anonymity protocols.
Further reading: paper


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Oct. 2012: Two papers accepted and presented at IEEE LCN 2012
Presented our papers "Dynamic File Bundling for Large-scale Content Distribution" and "Characterizing Cyberlocker Traffic Flows" at IEEE LCN. (See publications for details)


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Sept. 2012: Optimized tradeoffs between Cloud, P2P, and Servers
Present our paper "Tradeoffs in Cloud and Peer-assisted Content Delivery Systems" at IEEE International Conference on Peer-to-Peer Computing (P2P) 2012.
(See publications for details)


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Aug. 2012: Congrats Aniket and Youmna!
Two of the PhD students that I have been working with over last few years recently graduated: Aniket Mahanti (University of Calgary, Canada) and Youmna Borghol (UNSW and NICTA, Australia). Dr. Mahanti has taken a job as an assistant professor at University of Auckland, New Zeeland. Dr. Borghol is now a Data Analytics Manager at MediaCom, Australia.


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Aug. 2012: ACM KDD
Present our paper "The Untold Story of the Clones: Content-agnostic Factors that Impact YouTube Video Popularity", at the ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD), Beijing, China. This work was done during Youmna Borghol's internship at Linkoping University.
Further reading: paper


Aug. 2012: File-hosting paper at IEEE MASCOTS 2012
Aniket presents our paper "Content Sharing Dynamics in the Global File Hosting Landscape" at IEEE MASCOTS. (See publications for details)



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July 2012: Research trip to Canada (UofS and UofC)


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June 2012: ACM Greenmetrics 2012
For the fourth straight year I am co-organizing the GreenMetrics workshop collocated and sponsored by ACM SIGMETRICS. The workshop takes place at Imperial College, London, England, on June 11. We will have a great program with very good keynote speakers.
Further reading: workshop page


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June 2012: Analytic BT-like VoD paper in IEEE/ACM ToN
Our paper "Insights on Media Streaming Progress using BitTorrent-like Protocols for On-Demand Streaming" appears in IEEE/ACM Transactions on Networking (ToN). (See publications for details)


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June 2012: Passive Crowd-based Monitoring paper at IEEE ICC 2012
Jerry presents our paper "Passive Crowd-based Monitoring of World Wide Web Infrastructure and its Performance" at IEEE ICC. (See publications for details)


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Mar. 2012: Zongpeng Li (University of Calgary, Canada) visits
During his visit, Professor Li gives a talk "The multiple unicast network coding conjecture and a geometric framework for studying it".


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Mar 2012: Local and Global BitTorrent Workload Dynamics paper at PAM 2012
Presented our paper "A Longitudinal Characterization of Local and Global BitTorrent Workload Dynamics" at PAM. (See publications for details)


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Jan/Feb. 2012: PC Meeting ACM SIGMETRICS 2012
I recently attended the PC meeting in New York, NY. The conference will take place at Imperial College, London, England in June 2012.
Further reading: conference website


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Nov/Dec. 2011: Research trip to Canada (UofS and UofC)


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Oct. 2011: Two papers at IFIP PERFORMANCE 2011
Our papers "Characterizing and Modeling Popularity of User-generated Videos" and "Characterizing the File Hosting Ecosystem: A View from the Edge" were both accepted and presented at IFIP PERFORMANCE 2011.
Further details: See publications for papers and datasets


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Oct. 2011: Bye Youmna!
Youmna Borghol, Ph.D. student (UNSW and NICTA, Australia) finishes up her six month internship (Apr. 2011 - Oct. 2011) with me and heads back to Australia to finish up her PhD thesis. You will be missed Youmna!


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Oct. 2011: Sebastien Ardon (NICTA, Australia) visits
During the visit, Dr. Ardon will talk about "Geolocating IP Addresses in Cellular Data Networks" and Youmna Borghol will present our joint paper "Characterizing and Modeling Popularity of User-generated Videos", which will appear in IFIP PERFORMANCE 2011 next week.
Further reading: paper


Sept. 2011: Peer discovery/mixing paper at IEEE P2P 2011
Presented our paper "Efficient and Highly Available Peer Discovery: A Case for Independent Trackers and Gossiping" at IEEE P2P. (See publications for details)


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Sept. 2011: Bye Ajay!
Ajay Gopinathan finishes up his Postdoc (July 2011 - Sept 2011) with me and heads of for Google, CA, USA. Good luck with the new job at Google Ayaj!


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2011: Intelligence Gathering and Control
Our paper "Characterizing Intelligence Gathering and Control on an Edge Network" appears in ACM TOIT.
(See publications for details)


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2011: Journal paper success
During 2011 we have great success with some of our journal submissions. Our two most recent papers "Characterizing Web-based Video Sharing Workloads" and "Characterizing Intelligence Gathering and Control on an Edge Network" appear in ACM TWEB and ACM TOIT, respectively.
(See publications for details)


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Jun/Jul. 2011: Research trip to Canada (UofS and UofC)


June 2011: ACM Greenmetrics 2011
For the third straight year I am co-organizing the GreenMetrics workshop collocated and sponsored by ACM SIGMETRICS, both at FCRC 2011. The workshop takes place in San Jose, CA, on June X.
Further reading: workshop page


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June 2011: Anirban Mahanti (NICTA, Australia) visits


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Mar/Apr. 2011: Research trip to Canada (UofS and UofC)


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Mar. 2011: Utilization paper at ACM/SPEC ICPE 2011
Presented our paper "Towards More Effective Utilization of Computer Systems" at ACM/SPEC ICPE. (See publications for details)


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Jan. 2011: CENIIT project award
My CENIIT funded project "Scalable and Efficient Content Distribution" starts (475 kSEK / year).
Further reading: ceniit project


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Nov-Jan. 2010/2011: Research trip to Canada (UofS and UofC)


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Sept. 2010: First day at Linköping University
After 2 great years at University of Calgary, I begin the next chapter in my academic career. First day as an Assistant Professor.


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NEWS: General note
I am always looking for new graduate students, as well as students interested in thesis projects and/or general research-oriented projects.
Further reading: positions and projects