Institution
Orange S.A.
Company•Paris, France•
About: Orange S.A. is a company organization based out in Paris, France. It is known for research contribution in the topics: Terminal (electronics) & Signal. The organization has 6735 authors who have published 9190 publications receiving 156440 citations. The organization is also known as: Orange SA & France Télécom.
Papers published on a yearly basis
Papers
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02 Jul 2007TL;DR: New efficient constructions for public-key broadcast encryption that simultaneously enjoy the following properties are put forward: receivers are stateless; encryption is collusion-secure for arbitrarily large collusions of users and security is tight in the standard model.
Abstract: This paper puts forward new efficient constructions for public-key broadcast encryption that simultaneously enjoy the following properties: receivers are stateless; encryption is collusion-secure for arbitrarily large collusions of users and security is tight in the standard model; new users can join dynamically i.e. without modification of user decryption keys nor ciphertext size and little or no alteration of the encryption key. We also show how to permanently revoke any subgroup of users. Most importantly, our constructions achieve the optimal bound of O(1)-size either for ciphertexts or decryption keys, where the hidden constant relates to a couple of elements of a pairing-friendly group. Our broadcast-KEM trapdoor technique, which has independent interest, also provides a dynamic broadcast encryption system improving all previous efficiency measures (for both execution time and sizes) in the private-key setting.
287 citations
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TL;DR: A method called two-step noise reduction (TSNR) technique is proposed which solves this problem while maintaining the benefits of the decision-directed approach and a significant improvement is brought by HRNR compared to TSNR thanks to the preservation of harmonics.
Abstract: This paper addresses the problem of single-microphone speech enhancement in noisy environments. State-of-the-art short-time noise reduction techniques are most often expressed as a spectral gain depending on the signal-to-noise ratio (SNR). The well-known decision-directed (DD) approach drastically limits the level of musical noise, but the estimated a priori SNR is biased since it depends on the speech spectrum estimation in the previous frame. Therefore, the gain function matches the previous frame rather than the current one which degrades the noise reduction performance. The consequence of this bias is an annoying reverberation effect. We propose a method called two-step noise reduction (TSNR) technique which solves this problem while maintaining the benefits of the decision-directed approach. The estimation of the a priori SNR is refined by a second step to remove the bias of the DD approach, thus removing the reverberation effect. However, classic short-time noise reduction techniques, including TSNR, introduce harmonic distortion in enhanced speech because of the unreliability of estimators for small signal-to-noise ratios. This is mainly due to the difficult task of noise power spectrum density (PSD) estimation in single-microphone schemes. To overcome this problem, we propose a method called harmonic regeneration noise reduction (HRNR). A nonlinearity is used to regenerate the degraded harmonics of the distorted signal in an efficient way. The resulting artificial signal is produced in order to refine the a priori SNR used to compute a spectral gain able to preserve the speech harmonics. These methods are analyzed and objective and formal subjective test results between HRNR and TSNR techniques are provided. A significant improvement is brought by HRNR compared to TSNR thanks to the preservation of harmonics
286 citations
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TL;DR: A task duplication-based scheduling algorithm for network of heterogeneous systems (TANH), with complexity O(V/sup 2/), which provides optimal results for applications represented by directed acyclic graphs (DAGs), provided a simple set of conditions on task computation and network communication time could be satisfied.
Abstract: Optimal scheduling of parallel tasks with some precedence relationship, onto a parallel machine is known to be NP-complete. The complexity of the problem increases when task scheduling is to be done in a heterogeneous environment, where the processors in the network may not be identical and take different amounts of time to execute the same task. We introduce a task duplication-based scheduling algorithm for network of heterogeneous systems (TANH), with complexity O(V/sup 2/), which provides optimal results for applications represented by directed acyclic graphs (DAGs), provided a simple set of conditions on task computation and network communication time could be satisfied. The performance of the algorithm is illustrated by comparing the scheduling time with an existing "best imaginary level scheduling (BIL)" scheme for heterogeneous systems. The scalability for a higher or lower number of processors, as per their availability is also discussed. We have shown to provide substantial improvement over existing work on the task duplication-based scheduling algorithm (TDS).
283 citations
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14 Sep 2003TL;DR: In this article, the authors consider wireless downlink data channels where the transmission power of each base station is time-shared between a dynamic number of active users as in CDMA/HDR systems and derive analytical results relating user performance, in terms of blocking probability and data throughput, to cell size and traffic density.
Abstract: We consider wireless downlink data channels where the transmission power of each base station is time-shared between a dynamic number of active users as in CDMA/HDR systems. We derive analytical results relating user performance, in terms of blocking probability and data throughput, to cell size and traffic density. These results are used to address a number of practically interesting issues, including the trade-off between cell coverage and cell capacity and the choice of efficient scheduling and admission control schemes.
281 citations
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TL;DR: The general requirements for NG-PON1 to support various popular applications many service providers expressed interests on as well as to enable smooth migration from Gigabit PON are detailed.
Abstract: Gigabit-class passive optical networks have been standardized and are now being deployed. This article presents possible migration scenarios toward the next-generation PON and proposes a technology roadmap of evolutionary growth (termed NG-PON1) vs. revolutionary change (termed NG-PON2). This article then details the general requirements for NG-PON1 to support various popular applications many service providers expressed interests on as well as to enable smooth migration from Gigabit PON.
280 citations
Authors
Showing all 6762 results
Name | H-index | Papers | Citations |
---|---|---|---|
Patrick O. Brown | 183 | 755 | 200985 |
Martin Vetterli | 105 | 761 | 57825 |
Samy Bengio | 95 | 390 | 56904 |
Aristide Lemaître | 75 | 712 | 22029 |
Ifor D. W. Samuel | 74 | 605 | 23151 |
Mischa Dohler | 68 | 355 | 19614 |
Isabelle Sagnes | 67 | 753 | 18178 |
Jean-Jacques Quisquater | 65 | 335 | 18234 |
David Pointcheval | 64 | 298 | 19538 |
Emmanuel Dupoux | 63 | 267 | 14315 |
David Gesbert | 63 | 456 | 24569 |
Yonghui Li | 62 | 697 | 15441 |
Sergei K. Turitsyn | 61 | 722 | 14063 |
Joseph Zyss | 61 | 434 | 17888 |
Jean-Michel Gérard | 58 | 421 | 14896 |