Publications associées à Qualité d'expérience

Ultrahigh-quality-factor micro- and nanomechanical resonators using dissipation dilution

Tobias Kippenberg, Alberto Beccari, Nils Johan Engelsen

Mechanical resonators are widely used in sensors, transducers and optomechanical systems, where mechanical dissipation sets the ultimate limit to performance. Over the past 15 years, the quality factors in strained mechanical resonators have increased by f ...

Nature Portfolio2024

Learning a QoE Metric from Social Media and Gaming Footage

Catalina Paz Alvarez Inostroza, Aikaterini Argyraki

Defining a universal metric for Quality of Experience (QoE) is notoriously hard due to the complex relationship between low-level performance metrics and user satisfaction. The most common metric, the Mean Opinion Score (MOS), has well-known biases and inc ...

2023

Caching and Neutrality

Pavlos Nikolopoulos, Muhammad Abdullah, Aikaterini Argyraki

We are used to defining network neutrality as absence of traffic differentiation, like policing or shaping. These mechanisms, however, are often not what determines end-users’ quality of experience (QoE). Most content today is accessed through edge caches, ...

ACM Association for Computing Machinery2023

Towards JPEG AIC part 3: visual quality assessment of high to visually lossless image coding

Touradj Ebrahimi, Evgeniy Upenik, Michela Testolina

Due to the increasing number of pictures captured and stored every day by and on digital devices, lossy image compression has become inevitable to limit the needed storage requirement. As a consequence, these compression methods might introduce some visual ...

SPIE2022

Strained crystalline nanomechanical resonators with quality factors above 10 billion

Tobias Kippenberg, Sergey Fedorov, Alberto Beccari, Nils Johan Engelsen

In strained mechanical resonators, the concurrence of tensile stress and geometric nonlinearity dramatically reduces dissipation. This phenomenon, called dissipation dilution, is employed in mirror suspensions of gravitational-wave interferometers and at t ...

NATURE PORTFOLIO2022

Optimization of Edge Profile for Improved Anti-Resonance Quality Factor in Lithium Niobate SH0 Resonators

Luis Guillermo Villanueva Torrijo, Silvan Stettler

Thin-film lithium niobate (LNO) has been identified as a promising material platform for enabling high electromechanical coupling and low-loss piezoelectric resonators for filtering applications. In this work, the design and fabrication of fundamental shea ...

IEEE2022

A 49 mu W 6th-Order Chebyshev SSF-based Low-Pass Analog Filter for IEEE 802.11ax

Christian Enz, Alessandro Pezzotta, Daniel Mathias Bold, Salvatore Collura

In this paper a continuous-time low-pass analog filter based on the Cascoded Super Source Follower (C-SSF) architecture, implemented in a 28-nm bulk CMOS process, is presented. The target application is the transceiver analog baseband for the next-generati ...

IEEE2020

Context-based Quality of Experience in Immersive Multimedia

Anne-Flore Nicole Marie Perrin

Since 1895, when the Lumière brothers came out with the projected cinematograph, motion pictures and more generally multimedia contents have considerably improved and are still experiencing a very dynamic development. Advances involved improving various mo ...

EPFL2019

MAMUT: Multi-Agent Reinforcement Learning for Efficient Real-Time Multi-User Video Transcoding

David Atienza Alonso, Marina Zapater Sancho, Arman Iranfar, Luis Maria Costero Valero

Real-time video transcoding has recently raised as a valid alternative to address the ever-increasing demand for video contents in servers' infrastructures in current multi-user environments. High Efficiency Video Coding (HEVC) makes efficient online trans ...

IEEE2019

A Viewport-driven Multi-metric Fusion Approach for 360-Degree Video Quality Assessment

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo

We propose a new viewport-based multi-metric fusion (MMF) approach for visual quality assessment of 360-degree (omnidirectional) videos. Our method is based on computing multiple spatio-temporal objective quality metrics (features) on viewports extracted f ...

IEEE2020

Cross-Packet Coding for Delay-Constrained Streaming Applications

Dario Floreano, Giuseppe Cocco

Delay-constrained streaming from a moving platform is of paramount importance for applications such as the remote control of drones, where a low-delay video stream is required in order to provide visual feedback to the pilot while providing high quality vi ...

2019

Efficient User Guidance for Validating Participatory Sensing Data

Quoc Viet Hung Nguyen, Thành Tâm Nguyên

Participatory sensing has become a new data collection paradigm that leverages the wisdom of the crowd for big data applications without spending cost to buy dedicated sensors. It collects data from human sensors by using their own devices such as cell pho ...

ASSOC COMPUTING MACHINERY2019

Changer le mode de vie, changer la mobilité : voiture et sobriété

Alexandre André Robert Rigal

La présente thèse prend acte du réchauffement climatique et des injonctions à changer les modes de vie pour qu'ils gagnent en sobriété. Elle s’inscrit dans le mouvement de recherche qui vise à changer les modes de vie à partir de transformations dans les m ...

EPFL2018

Collaborative Filtering Under a Sybil Attack: Similarity Metrics do Matter!

Rachid Guerraoui, Anne-Marie Kermarrec, Antoine Rault, Davide Frey, Florestan Laurentin Marie De Moor

Recommendation systems help users identify interesting content, but they also open new privacy threats. In this paper, we deeply analyze the effect of a Sybil attack that tries to infer information on users from a user-based collaborative-filtering recomme ...

IEEE2018

A novel methodology for quality assessment of voxelized point clouds

Touradj Ebrahimi, Evangelos Alexiou

Recent trends in multimedia technologies indicate a significant growth of interest for new imaging modalities that aim to provide immersive experiences by increasing the engagement of the user with the content. Among other solutions, point clouds denote an ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Online Efficient Bio-Medical Video Transcoding on MPSoCs Through Content-Aware Workload Allocation

David Atienza Alonso, Marina Zapater Sancho, Arman Iranfar, Ali Pahlevan

Bio-medical image processing in the field of telemedicine, and in particular the definition of systems that allow medical diagnostics in a collaborative and distributed way is experiencing an undeniable growth. Due to the high quality of bio-medical videos ...

IEEE and ACM Press2018

Exploring manycore architectures for next-generation HPC systems through the MANGO approach

David Atienza Alonso, Marina Zapater Sancho, Arman Iranfar, Simone Libutti

The Horizon 2020 MANGO project aims at exploring deeply heterogeneous accelerators for use in High Performance Computing systems running multiple applications with different Quality of Service (QoS) levels. The main goal of the project is to exploit custom ...

ELSEVIER SCIENCE BV2018

An Inexact Ultra-low Power Bio-signal Processing Architecture With Lightweight Error Recovery

David Atienza Alonso, Giovanni Ansaloni, Ruben Braojos Lopez, Soumya Subhra Basu, Loris Gérard Duch

The energy efficiency of digital architectures is tightly linked to the voltage level (Vdd) at which they operate. Aggressive voltage scaling is therefore mandatory when ultra-low power processing is required. Nonetheless, the lowest admissible Vdd is ofte ...

Assoc Computing Machinery2017

An Inexact Ultra-low Power Bio-signal Processing Architecture With Lightweight Error Recovery

David Atienza Alonso, Giovanni Ansaloni, Ruben Braojos Lopez, Soumya Subhra Basu, Loris Gérard Duch

The energy e fficiency of digital architectures is tightly linked to the voltage level (Vdd) at which they operate. Aggressive voltage scaling is therefore mandatory when ultra-low power processing is required. Nonetheless, the lowest admissible Vdd is o e ...

2017

Towards subjective quality assessment of point cloud imaging in augmented reality

Touradj Ebrahimi, Evgeniy Upenik, Evangelos Alexiou

Recently, there has been an increased interest in capture, processing and rendering of visual content in form of point clouds. Among other challenges, subjective and objective quality evaluation of point clouds are still open problems. Most proposed subjec ...

2017