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Introduction
Publications
Publications (176)
Video dissemination through sites such as YouTube can have widespread impacts
on opinions, thoughts, and cultures. Not all videos will reach the same
popularity and have the same impact. Popularity differences arise not only
because of differences in video content, but also because of other
"content-agnostic" factors. The latter factors are of cons...
The popularity of contents on the Internet is often said to follow a Zipf-like distribution. Different measurement studies showed, however, significantly different distributions depending on the measurement methodology they followed. We performed a large-scale measurement of the most popular peer-to-peer (P2P) content distribution system, BitTorren...
A peer-assisted content delivery system uses the upload band- width of its clients to assist in delivery of popular content. In peer- assisted systems using a BitTorrent-like protocol, a content delivery server seeds the offered files, and active torrents form when multiple clients make closely-spaced requests for the same content. Scalability is a...
This paper develops a framework for studying the popularity dynamics of user-generated videos, presents a characterization of the popularity dynamics, and proposes a model that captures the key properties of these dynamics. We illustrate the biases that may be introduced in the analysis for some choices of the sampling technique used for collecting...
Video on demand, particularly with user-generated content, is emerging as one of the most bandwidth-intensive applications on the Internet. Owing to content control and other issues, some video-on-demand systems attempt to prevent downloading and peer-to-peer content delivery. Instead, such systems rely on server replication, such as via third-part...
The evaluation of player performance is an important topic in sports analytics and is used for team management, scouting, and in sports broadcasts. When evaluating the performance of ice hockey players, many metrics are used, including traditional metrics such as goals, assists, and points and more recent metrics such as Corsi and expected goals. O...
Despite the clear dominance of video streaming traffic on the Internet and the significant ramifications of disclosure of which videos users are streaming, video fingerprinting has received relatively little attention compared to other traffic analysis domains. Existing attacks are tailored to undefended traffic and mostly rely on a few manually cr...
Performance and age have an intertwined relationship in soccer. However, despite the sport’s popularity and the great value of insight
into this topic to decision-making personnel, this is a fairly unexplored
topic, particularly for lower-ranked leagues. In this paper, we use a novel
performance metric to investigate the peak age among soccer playe...
Although analytics is being used in, e.g., the evaluation of players and scouting, it is still challenging to quantify skills and playing styles of players. Such information is important for roster creation and scouting, where teams want to find players that have a playing style that fits within the team, as well as for game preparation to understa...
In this era of ubiquitous surveillance and online presence, protecting facial privacy has become a critical concern for individuals and society as a whole. Adversarial attacks have emerged as a promising solution to this problem, but current methods are limited in quality or are impractical for sensitive domains such as facial editing. This paper p...
Every time we use the web, we place our trust in X.509 certificates binding public keys to domain identities. However, for these certificates to be trustworthy, proper issuance, management, and timely revocations (in cases of compromise or misuse) are required. While great efforts have been placed on ensuring trustworthiness in the issuance of new...
The decentralized nature of Bitcoin allows for pseudonymous money exchange beyond authorities’ control, contributing to its popularity for diverse illegal activities such as scams, ransomware attacks, money laundering, and black markets. In this paper, we characterize this landscape, providing insights into similarities and differences in the use o...
Understanding the role of a particular player, or set of players, in a team is an important tool for players, scouts, and managers,
as it can improve training, game adjustments and team construction.
In this paper, we propose a probabilistic method for quantifying player
roles in ice hockey that allows for a player to belong to different roles
with...
This paper explores the significance of special teams, particularly powerplay, in ice hockey. Despite the commonly held perception of their importance, little research has examined the impact of powerplay and penalty kill performance on overall team success. The paper uses several seasons of NHL data to characterize goal-scoring and manpower opport...
To capture that not all goals are of the same importance, a new performance metric called the Game Points Importance Value (GPIV) was recently proposed. While this metric takes into account the expected impact that a goal has on the outcome of a game based on the context when the goal was scored, it relies on a relatively fine-grained state space....
The proliferation of news on social media platforms has led to concerns about the impact of biased and unreliable information on public discourse. This study examines differences in interaction patterns between public and private sharing of news articles on Facebook, focusing on articles with varying bias and reliability, as well as the depth of in...
The reliability and political bias differ substantially between news articles published on the Internet. Recent research has examined how these two variables impact user engagement on Facebook, reflected by measures like the volume of shares, likes, and other interactions. However, most of this research is based on the ratings of publishers (not ne...
Privacy of machine learning models is one of the remaining challenges that hinder the broad adoption of Artificial Intelligent (AI). This paper considers this problem in the context of image datasets containing faces. Anonymization of such datasets is becoming increasingly important due to their central role in the training of autonomous cars, for...
Privacy of machine learning models is one of the remaining challenges that hinder the broad adoption of Artificial Intelligent (AI). This paper considers this problem in the context of image datasets containing faces. Anonymization of such datasets is becoming increasingly important due to their central role in the training of autonomous cars, for...
Dual Connectivity (DC) is an important lower-layer feature accelerating the transition from 4G to 5G that also is expected to play an important role in standalone 5G radio networks. However, even though the packet reordering introduced by DC can significantly impact the performance of upper-layer protocols, no prior work has studied the impact of D...
LINHAC 2022 took place from June 6-8, 2022, and was organized by Linköping University (Patrick Lambrix and Niklas Carlsson) and Linköping Hockey Club (Mikael Vernblom). LINHAC brought together professionals and academics with an interest in hockey analytics. It featured the latest research in hockey analytics in academia and companies, discussions...
The evaluation of player performance is an important topic in sports analytics and is used by coaches for team management, in scouting and in sports broadcasts. When evaluating the performance of ice hockey players, many metrics are used, including traditional metrics such as goals, assists, points and modern metrics such as Corsi. One weakness of...
The ACM Proceedings of the ACM on Measurement and Analysis of Computing Systems (POMACS) focuses on the measurement and performance evaluation of computer systems and operates in close collaboration with the ACM Special Interest Group SIGMETRICS. All papers in this issue of POMACS will be presented during the ACM SIGMETRICS/Performance 2022 confere...
The demand and usage of 360°video services are expected to increase. However, despite these services being highly bandwidth intensive, not much is known about the potential value that basic bandwidth saving techniques such as server or edge-network on-demand caching (e.g., in a CDN) could have when used for delivery of such services. This problem i...
Predicting game or season outcomes is important for clubs as well as for the betting industry. Understanding the critical factors of winning games and championships gives clubs a competitive advantage when selecting players for the team and implementing winning strategies. In this paper, we work with NBA data from 10 seasons and propose an approach...
The modern Internet is highly dependent on trust communicated via certificates. However, in some cases, certificates become untrusted, and it is necessary to revoke them. In practice, the problem of secure revocation is still open. Furthermore, the existing procedures do not leave a transparent and immutable revocation history. We propose and evalu...
The ACM Proceedings of the ACM on Measurement and Analysis of Computing Systems (POMACS) focuses on the measurement and performance evaluation of computer systems and operates in close collaboration with the ACM Special Interest Group SIGMETRICS. All papers in this issue of POMACS will be presented during the ACM SIGMETRICS/Performance 2022 confere...
Certificates are the foundation of secure communication over the internet. However, not all certificates are created and managed in a consistent manner and the certificate authorities (CAs) issuing certificates achieve different levels of trust. Furthermore, user trust in public keys, certificates, and CAs can quickly change. Combined with the expe...
Dual Connectivity (DC) is an important lower-layer feature accelerating the transition from 4G to 5G that also is expected to play an important role in standalone 5G. However, even though the packet reordering introduced by DC can significantly impact the performance of upper-layer protocols, no prior work has studied the impact of DC on QUIC. In t...
The ACM Proceedings of the ACM on Measurement and Analysis of Computing Systems (POMACS) focuses on the measurement and performance evaluation of computer systems and operates in close collaboration with the ACM Special Interest Group SIGMETRICS. All papers in this issue of POMACS will be presented during the ACM SIGMETRICS/Performance 2022 confere...
Content-delivery applications can achieve scalability and reduce wide-area network traffic using geographically distributed caches. However, each deployed cache has an associated cost, and under time-varying request rates (e.g., a daily cycle) there may be long periods when the request rate from the local region is not high enough to justify this c...
Congestion-aware scheduling in case of downlink cellular communication has ignored the distribution of diverse content to different clients with heterogeneous secrecy requirements. Other possible application areas that encounter the preceding issue are secure offloading in mobile-edge computing, and vehicular communication. In this paper, we extend...
PAM2021 presentation of the paper "Revocation Statuses on the Internet". Length: 8 minutes.
Predicting game or season outcomes is important for clubs as well as for the betting industry. Understanding the critical factors of winning games and championships gives clubs a competitive advantage when selecting players for the team and implementing winning strategies. In this paper, we work with NBA data from 10 seasons and propose an approach...
The evaluation of player performance is an important topic in sport analytics and is used by coaches for team management, in scouting and in sports broadcasts.
When evaluating the performance of ice hockey players many metrics are used, including traditional metrics such as goals, assists, points and modern metrics such as Corsi. One weakness of su...
The modern Internet is highly dependent on the trust communicated via X.509 certificates. However, in some cases certificates become untrusted and it is necessary to revoke them. In practice, the problem of secure certificate revocation has not yet been solved, and today no revocation procedure (similar to Certificate Transparency w.r.t. certificat...
The modern Internet is highly dependent on the trust communicated via X.509 certificates. However, in some cases certificates become untrusted and it is necessary to revoke them. In practice, the problem of secure certificate revocation has not yet been solved, and today no revocation procedure (similar to Certificate Transparency w.r.t. certificat...
Dual Connectivity (DC) is an important lower-layer feature accelerating the transition from 4G to 5G that also is expected to play an important role in standalone 5G. However, even though the packet reordering introduced by DC can significantly impact the performance of upper-layer protocols, no prior work has studied the impact of DC on QUIC. In t...
Short end-to-end path lengths and faster round-trip times (RTTs) are important for good client performance. While prior measurement studies related to IPv6 primarily focus on various adoption aspects, much less work have focused on performance metrics such as these. In this paper, we compare the relative end-to-end path distances and RTTs when usin...
Virtual reality (VR) provides many exciting new application opportunities, but also present new challenges. In contrast to 360\(^{\circ }\) videos that only allow a user to select its viewing direction, in fully immersive VR, users can also move around and interact with objects in the virtual world. To most effectively deliver such services it is t...
Player behaviors can have a significant impact on the outcome of individual events, as well as the game itself. The increased availability of high quality resolution spatio-temporal data has enabled analysis of player behavior and game strategy. In this paper, we present the implementation and evaluation of an imitation learning method using recurr...
Many teams in the NHL utilize data analysis and employ
data analysts. An important question for these analysts
is to identify attributes and skills that may help predict the success of individual players. This study uses detailed player statistics from four seasons, player rankings from EA's NHL video games, and six machine learning algorithms to...
Internet security and privacy stand on the trustworthiness of public certificates signed by Certificate Authorities (CAs). However, software products do not trust the same CAs and therefore maintain different root stores, each typically containing hundreds of trusted roots capable of issuing "trusted" certificates for any domain. Incidents with mis...
Internet security and privacy stand on the trustworthiness of public certificates signed by Certificate Authorities (CAs). However, software products do not trust the same CAs and therefore maintain different root stores, each typically containing hundreds of trusted roots capable of issuing "trusted" certificates for any domain. Incidents with mis...
In this paper, we consider the two-user broadcast channel with security constraints. We assume that a source broadcasts packets to two receivers, and that one of them has secrecy constraints, i.e., its packets need to be kept secret from the other receiver. The receiver with secrecy constraint has full-duplex capability, allowing it to transmit a j...
Client-side encryption (CSE) is important to ensure that only the intended users have access to information stored in public cloud services. However, CSE complicates file synchronization methods such as deduplication and delta encoding, important to reduce the large network bandwidth overheads associated with cloud storage services. To investigate...
The Web of Things (WoT) is a new paradigm resulting from the integration of the Web with the Internet of Things. With the emergence of WoT comes the need for benchmarking tools to aid in performance evaluation studies that can be used to guide actual deployments of WoT infrastructure. In this paper we introduce WoTbench, a Web benchmarking framewor...
During viewing of interactive "branched video", users are asked to make viewing choices that impact the storyline of the video playback. This type of video puts the users in control of their viewing experiences and provides content creators with great flexibility how to personalize the viewing experience of individual viewers. However, in contrast...
Ice hockey is a highly popular sport that has seen significant increase in the use of sport analytics. To aid in such analytics, most major leagues collect and share increasing amounts of play-by-play data and other statistics. Additionally, some websites specialize in making such data available to the public in user-friendly forms. However, these s...
The demand and usage of 360$^{\circ}$ video services are expected to increase. However, despite these services being highly bandwidth intensive, not much is known about the potential value that basic bandwidth saving techniques such as server or edge-network on-demand caching (e.g., in a CDN) could have when used for delivery of such services. This...
A commonly used method to evaluate player performance is to attribute values to the different actions that players perform and sum up these values every time a player performs these actions. In ice hockey, such metrics include the number of goals, assists, points, plus-minus statistics and recently Corsi and Fenwick. However, these metrics do not c...
To overcome the shortcomings of simple metrics for evaluating player performance, recent works have introduced more advanced metrics that take into account the context of the players’ actions and perform look-ahead. However, as ice hockey is a team sport, knowing about individual ratings is not enough and coaches want to identify players that play...
As the success of a team depends on the performance of individual players, the valuation of player performance has become an important research topic. In this paper, we compare and contrast which attributes and skills best predict the success of individual players in their positions in five European top football leagues. Further, we evaluate differ...
This 2-page extended abstract provides an overview of the key results presented in more detail in our full length paper, with the same title, to appear in Performance Evaluation [2].
Cloud services and other shared third-party infrastructures allow individual content providers to easily scale their services based on current resource demands. In this paper, we consider an individual content provider that wants to minimize its delivery costs under the assumptions that the storage and bandwidth resources it requires are elastic, t...
With 360$^{\circ}$ video, only a limited fraction of the full view is displayed at each point in time. This has prompted the design of streaming delivery techniques that allow alternative playback qualities to be delivered for each candidate viewing direction. However, while prefetching based on the user's expected viewing direction is best done cl...
In this paper we consider the two-user broadcast channel with security constraints. We assume that one of the receivers has a secrecy constraint; i.e., its packets need to be kept secret from the other receiver. The receiver with secrecy constraint has full-duplex capability to transmit a jamming signal to increase its secrecy. We derive the averag...
Cloud services and other shared third-party infrastructures allow individual content providers to easily scale their services based on current resource demands. In this paper, we consider an individual content provider that wants to minimize its delivery costs under the assumptions that the storage and bandwidth resources it requires are elastic, t...
As the success of a team depends on the performance of individual players, the valuation of player performance has become an important research topic.
In this paper, we compare and contrast which attributes and skills best predict the success of individual players in their positions in five European top football leagues. Further, we evaluate diffe...
To overcome the shortcomings of simple metrics for evaluating player performance, recent works have introduced more advanced metrics that take into account the context of the players' actions and perform look-ahead.
However, as ice hockey is a team sport, knowing about individual ratings is not enough and coaches want to identify players that play...
With 360° video, only a limited fraction of the full view is displayed at each point in time. This has prompted the design of streaming delivery techniques that allow alternative playback qualities to be delivered for each candidate viewing direction. However, while prefetching based on the user's expected viewing direction is best done close to pl...
By caching content at geographically distributed servers, content delivery applications can achieve scalability and reduce wide-area network traffic. However, each deployed cache has an associated cost. When the request rate from the local region is sufficiently high this cost will be justified, but as the request rate varies, for example according...
Certificate Transparency (CT) was developed to mitigate shortcomings in the TLS/SSL landscape and to assess the trustworthiness of Certificate Authorities (CAs) and the certificates they create. With CT, certificates should be logged in public, audible, append-only CT logs and servers should provide clients (browsers) evidence, in the form of Signe...