Nicolas Gac Professeur des universités, université Paris-Saclay

Identifiants chercheurs

IdHAL :

nicolas-gac

ORCID :

0000-0001-6981-0368

IdRef :

137532008

Présentation

After an M.Sc. (2003) and a Ph.D. (2008) degrees, both in signal processing, from the Institut National Polytechnique de Grenoble, I joined in 2009 the University Paris-Saclay first at laboratory L2S as an associate professor and then in 2023 at SATIE as a full professor. I am teaching computer science for embedded systems at the faculty of science. At SATIE, my research interest is focused on algorithm-architecture co-design applied mainly for tomography reconstruction and radio astronomy on multi-GPU servers or FPGA boards.

Detailed CV : https://sdrive.cnrs.fr/s/foKxoD2FaKdwD8Y

Contact : prenom.nom @ universite-paris-saclay.fr

Laboratoire SATIE / Bureau 2S-73 ENS Paris-Saclay 4 avenue des Sciences / 91 190 Gif-sur-Yvette

Publications

Article dans une revue (16)

X-ray tomography reconstruction accelerated on FPGA through High-Level Synthesis tools Daouda Diakite,Nicolas Gac IEEE Transactions on Biomedical Circuits and Systems, 2023, pp.1-14. ⟨10.1109/TBCAS.2023.3258879⟩ Article dans une revue hal-04021970v1
Fast Grid to Grid Interpolation for Radio Interferometric Imaging Nicolas Monnier,François Orieux,Nicolas Gac,Cyril Tasse,Erwan Raffinet al. Astronomy and Computing, 2023, 45, pp.100767. ⟨10.1016/j.ascom.2023.100767⟩ Article dans une revue hal-04264131v2
Computing Large 2D Convolutions on GPU Efficiently with the im2tensor Algorithm Mickael Seznec,Nicolas Gac,François Orieux,Alvin Sashala Naik Journal of Real-Time Image Processing, 2022, 19, pp.1035-1047. ⟨10.1007/s11554-022-01240-0⟩ Article dans une revue hal-03742005v1
Real-Time Optical Flow Processing on Embedded GPU: a Hardware-Aware Algorithm to Implementation Strategy Mickaël Seznec,Nicolas Gac,François Orieux,Alvin Sashala Naik Journal of Real-Time Image Processing, 2022, 19 (2), pp.317-329. ⟨10.1007/s11554-021-01187-8⟩ Article dans une revue hal-03457011v1
3D Tomography back-projection parallelization on Intel FPGAs using OpenCL Maxime Martelli,Nicolas Gac,Alain Mérigot,Cyrille Enderli Journal of Signal Processing Systems, 2019, 91 (7), pp.1939-8115. ⟨10.1007/s11265-018-1403-6⟩ Article dans une revue hal-01831884v1
ROHSA: Regularized Optimization for Hyper-Spectral Analysis Antoine Marchal,Marc-Antoine Miville-Deschênes,François Orieux,Nicolas Gac,Charles Soussenet al. Astronomy & Astrophysics - A&A, 2019, 626, pp.A101. ⟨10.1051/0004-6361/201935335⟩ Article dans une revue hal-02147300v1
Error-Splitting Forward Model for Iterative Reconstruction in X-ray Computed Tomography and application with Gauss-Markov-Potts prior Camille Chapdelaine,Ali Mohammad-Djafari,Nicolas Gac,Estelle Parra IEEE Transactions on Computational Imaging, 2019, 5 (2), pp.317 - 332. ⟨10.1109/TCI.2018.2885432⟩ Article dans une revue hal-01948680v1
Bayesian 3D X-ray Computed Tomography with a Hierarchical Prior model for Sparsity in Haar Transform domain Li Wang,Ali Mohammad-Djafari,Nicolas Gac,Mircea Dumitru Entropy, 2018, Special Issue "Probabilistic Methods for Inverse Problems", ⟨10.3390/e20120977⟩ Article dans une revue hal-01950706v1
X-ray Computed Tomography using a sparsity enforcing prior model based on Haar transformation in a Bayesian framework Li Wang,Ali Mohammad-Djafari,Nicolas Gac Fundamenta Informaticae, 2017, 155 (4), pp.449-480. ⟨10.3233/FI-2017-1594⟩ Article dans une revue hal-01490523v1
A 3D Bayesian Computed Tomography Reconstruction Algorithm with Gauss-Markov-Potts Prior Model and its Application to Real Data Camille Chapdelaine,Ali Mohammad-Djafari,Nicolas Gac,Estelle Parra-Denis Fundamenta Informaticae, 2017, 155 (4), pp.373-405. ⟨10.3233/FI-2017-1591⟩ Article dans une revue hal-01569332v1
Toward a numerical deshaker for PFS Frédéric Schmidt,Irina Shatalina,Matthieu Kowalski,Nicolas Gac,Bortolino Sagginet al. Planetary and Space Science, 2014, 91, pp.45 - 51. ⟨10.1016/j.pss.2013.11.012⟩ Article dans une revue hal-01102830v1
A robust super-resolution approach with sparsity constraint in acoustic imaging Ning Chu,José Picheral,Ali Mohammad-Djafari,Nicolas Gac Applied Acoustics, 2014, 76, pp.197-208. ⟨10.1016/j.apacoust.2013.08.007⟩ Article dans une revue hal-00794236v8
Algorithmes de reconnaissance NCTR et parallélisation sur GPU Thomas Boulay,Nicolas Gac,Ali Mohammad-Djafari,Julien Lagoutte Traitement du Signal, 2013, 6, pp.309-342. ⟨10.3166/TS.30.309-342⟩ Article dans une revue hal-00930953v1
Experimental results and first 22Na source image reconstruction by two prototype modules in coincidence of a liquid xenon positron emission tomograph for small animal imaging M.L. Gallin-Martel,Yannick Grondin,Nicolas Gac,Y. Carcagno,L. Gallin-Martelet al. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2012, 682, pp.66-74. ⟨10.1016/j.nima.2012.04.006⟩ Article dans une revue hal-00703776v1
High Speed 3D Tomography on CPU, GPU, and FPGA Nicolas Gac,Stéphane Mancini,Michel Desvignes,Dominique Houzet EURASIP Journal on Embedded Systems, 2008, 2008, http://www.hindawi.com/GetArticle.aspx?doi=10.1155/2008/930250. ⟨10.1155/2008/930250⟩ Article dans une revue hal-00367321v1
Application d'un cache 2D prédictif à l'accélération de la rétroprojection TEP 2D Stéphane Mancini,Nicolas Gac,Michel Desvignes,O. Bourrion,O. Rossetto Traitement du Signal, 2006, 23, pp.Numéro 5-6 Article dans une revue hal-00122552v1

Chapitre d'ouvrage (1)

Prototypage rapide d'un supercalculateur dédié à la radioastronomie Nicolas Gac,Jean-François Nezan,André Ferrari,Chiara Ferrari,Martin Quinsonet al. L'Interdisciplinarité. Voyages au-delà des disciplines, CNRS Edition, 2023, 978-2-271-13983-2 Chapitre d'ouvrage hal-03704333v1

HDR (1)

Adéquation algorithme architecture pour l’accélération de méthodes d’inversion de données en grande dimension Nicolas Gac Traitement du signal et de l'image [eess.SP]. Université Paris Saclay, 2020 HDR tel-03090950v2

Thèse (1)

Adéquation Algorithme Architecture pour la reconstruction 3D en imagerie médicale TEP Nicolas Gac Traitement du signal et de l'image [eess.SP]. Institut National Polytechnique de Grenoble - INPG, 2008. Français. ⟨NNT : ⟩ Thèse tel-00330365v1

Communication dans un congrès (68)

Scalable Hydrodynamics on multiple Field-Programmable Gate Arrays (FPGAs) François-Xavier Mordant,Charles Prouveur,Pascal Tremblin,Nicolas Gac SC Workshops '25: Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis, Nov 2025, St Louis, United States. pp.1832-1841, ⟨10.1145/3731599.3767545⟩ Communication dans un congrès hal-05390519v1
SimSDP, a Rapid Prototyping tool for Radio Astronomy: From NenuFAR Experiments to SKAO-Scale Simulation Ophélie Renaud,Nicolas Gac,François Orieux,Cedric Dumez-Viou SiPS 2025 - 38th IEEE Workshop on Signal Processing Systems, Nov 2025, Hong Kong, China. pp.1-5 Communication dans un congrès hal-05260888v2
Extension du prototypage rapide pour les pipelines d’imagerie radioastronomique : Simulation avancée multi-nœud HPC Ophélie Renaud,Sunrise Wang,Nicolas Gac,François Orieux GRETSI 2025 - 30e Colloque sur le traitement du signal et des images, GRETSI - Groupe de Recherche en Traitement du Signal et des Images, Aug 2025, Strasbourg, France. pp.1-4 Communication dans un congrès hal-05216024v2
A practical HW-aware NAS flow for AI vision applications on embedded heterogeneous SoCs Agathe Archet,Nicolas Ventroux,Nicolas Gac,François Orieux 18th Workshop on Design and Architectures for Signal and Image Processing (DASIP 2025), Jan 2025, Barcelone, Spain. pp.43-56, ⟨10.1007/978-3-031-87897-8_4⟩ Communication dans un congrès hal-04869471v1
Dark-era : Dataflow Algorithm aRchitecture co-design of SKA pipeline for Exascale Radio Astronomy Nicolas Gac,Ophélie Renaud SaLF 2025 - 11th Annual conference on Science At Low Frequencies, Dec 2025, Orléans, France Communication dans un congrès hal-05430702v1
Projet ANR Dark-era : Adéquation Algorithme Architecture (A3) pour la radioastronomie Nicolas Gac Colloque national du GDR SoC2, Jun 2024, Toulouse, France Communication dans un congrès hal-04611829v1
An Initial Framework for Prototyping the Radio-Interferometric Imaging Pipelines Sunrise Wang,Nicolas Gac,Hugo Miomandre,Jean-François Nezan,Karol Desnoset al. DASIP 2024 - Workshop on Design and Architectures for Signal and Image Processing, HiPEAC, Jan 2024, Munich, Germany. pp 56-67, ⟨10.1007/978-3-031-62874-0_5⟩ Communication dans un congrès hal-04361151v3
Exploration d'architectures de réseaux de neurones pour la segmentation sémantique d'images aériennes Agathe Archet,François Orieux,Nicolas Ventroux,Nicolas Gac GRETSI 2023 - XXIXème Colloque Francophone de Traitement du Signal et des Images, Aug 2023, Grenoble, France Communication dans un congrès hal-04148565v1
Energy-efficient use of an embedded heterogeneous SoC for the inference of CNNs Agathe Archet,Nicolas Ventroux,Nicolas Gac,François Orieux 2023 26th Euromicro Conference on Digital System Design (DSD), Sep 2023, Durrës, Albania Communication dans un congrès hal-04148582v1
Embedded AI performances of Nvidia's Jetson Orin SoC series Agathe Archet,Nicolas Gac,François Orieux,Nicolas Ventroux 17ème Colloque National du GDR SOC2, Jun 2023, Lyon, France Communication dans un congrès hal-04186977v1
Interpolation Rapide Sky to Sky pour l'Imagerie Radio Interférométrique Nicolas Monnier,François F. Orieux,Nicolas Gac,David Guibert,Cyril Tasseet al. GRETSI 2022 - XXIIXème Colloque Francophone de Traitement du Signal et des Images, Sep 2022, Nancy, France Communication dans un congrès hal-03696220v1
FPGA implementation of 2D Convolution using OneAPI and OpenCL Daouda Diakite,Nicolas Gac 16ème Colloque National du GDR SOC2, Jun 2022, Strasbourg, France Communication dans un congrès hal-03695100v1
Premiers résultats de comparaison des outils oneAPI et OpenCL pour la convolution 2D sur FPGA Daouda Diakite,Nicolas Gac GRETSI 2022 - XXIIXème Colloque Francophone de Traitement du Signal et des Images, Sep 2022, Nancy, France Communication dans un congrès hal-03695087v1
MobileFlow : modèle et mise en œuvre pour une inférence de flot optique efficace Mickael Seznec,Agathe Archet,Nicolas Gac,François Orieux,Alvin Sashala Naik GRETSI 2022 - XXIIXème Colloque Francophone de Traitement du Signal et des Images, Sep 2022, Nancy, France Communication dans un congrès hal-03695558v2
Fast Sky to Sky Interpolation for Radio Interferometric Imaging Nicolas Monnier,François Orieux,Nicolas Gac,Cyril Tasse,Erwan Raffinet al. 29th IEEE International Conference on Image Processing (ICIP 2022), Oct 2022, Bordeaux, France. ⟨10.1109/ICIP46576.2022.9897317⟩ Communication dans un congrès hal-03725824v2
Multi-core multi-node parallelization of the radio interferometric imaging pipeline DDFacet Nicolas Monnier,David Guibert,Cyril Tasse,Nicolas Gac,François F. Orieuxet al. SiPS22-IEEE Workshop on Signal Processing Systems, Nov 2022, Rennes, France. ⟨10.1109/sips55645.2022.9919239⟩ Communication dans un congrès hal-03729202v1
Memory prefetching for tomography acceleration on FPGAs through HLS tools Daouda Diakite,Nicolas Gac 15ème Colloque National du GDR SOC2, Jun 2021, Rennes, France Communication dans un congrès hal-03240542v1
OpenCL FPGA Optimization guided by memory accesses and roofline model analysis applied to tomography acceleration Daouda Diakite,Nicolas Gac,Maxime Martelli 31st International Conference on Field Programmable Logic and Applications (FPL), Aug 2021, Dresden (virtual), Germany. pp.109-114, ⟨10.1109/FPL53798.2021.00026⟩ Communication dans un congrès hal-03226257v2
Student Session: Data distribution on a multi-GPU node for TomoBayes CT reconstruction Mohammed Chghaf,Nicolas Gac 2020 IEEE 26th International Conference on Embedded and Real-Time Computing Systems and Applications (RTCSA), Aug 2020, Gangnueng, South Korea. pp.1-2, ⟨10.1109/RTCSA50079.2020.9203709⟩ Communication dans un congrès hal-04539697v1
An efficiency-driven approach for real-time optical flow processing on parallel hardware Mickael Seznec,Nicolas Gac,F. Orieux,A. Sashala Naik IEEE International Conference on Image Processing (ICIP’2020), Oct 2020, Abu Dhabi, United Arab Emirates. ⟨10.1109/icip40778.2020.9191164⟩ Communication dans un congrès hal-02604755v1
Data distribution on a multi-GPU node for TomoBayes CT reconstruction Mohammed Chghaf,Nicolas Gac The 26th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications, Aug 2020, Inconnu, South Korea Communication dans un congrès hal-02586239v4
An OpenCL pipeline implementation on Intel FPGA for 3D backprojection Daouda Diakite,Maxime Martelli,Nicolas Gac 6th International Conference on Image Formation in X-Ray Computed Tomography, Aug 2020, Regensburg, Germany Communication dans un congrès hal-02500994v2
Accélération sur GPU d'une simulation radar avec OpenACC Maxime Martelli,Cyrille Enderli,Nicolas Gac,Antoine Vermesse,Alain Mérigot GRETSI 2019 - XXVIIème Colloque francophone de traitement du signal et des images, Aug 2019, Lille, France Communication dans un congrès hal-02147363v1
Variational Bayesian approach in model-based iterative reconstruction for 3D X-ray computed tomography with Gauss-Markov-Potts prior Camille Chapdelaine,Ali Mohammad-Djafari,Nicolas Gac,Estelle Parra-Denis MaxEnt 2019 : Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering, Jun 2019, Garching/Munich, Germany. ⟨10.3390/proceedings2019033004⟩ Communication dans un congrès hal-02132706v1
GPU Acceleration : OpenACC for Radar Processing Simulation Maxime Martelli,Cyrille Enderli,Nicolas Gac,Antoine Vermesse,Alain Mérigot International Radar Conference, Sep 2019, Toulon, France. pp.1-6, ⟨10.1109/RADAR41533.2019.171296⟩ Communication dans un congrès hal-02129441v1
Multi-streaming and multi-GPU optimization for a matched pair of Projector and Backprojector Nicolas Georgin,Camille Chapdelaine,Nicolas Gac,Ali Mohammad-Djafari,Estelle Parra-Denis The 2019 International Conference on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, Jun 2019, Philadelphie, PA, United States. ⟨10.1117/12.2534108⟩ Communication dans un congrès hal-02070223v1
Harnessing FPGAs potential with OpenCL Maxime Martelli,Nicolas Gac,Alain Mérigot,Cyrille Enderli 13ème Colloque nationale du GDR SoC/SiP, Jun 2018, Paris, France Communication dans un congrès hal-01841029v1
New GPU implementation of Separable Footprint (SF) Projector and Backprojector : first results Camille Chapdelaine,Nicolas Gac,Ali-Mohammad Djafari,Estelle Parra-Denis The Fifth International Conference on Image Formation in X-Ray Computed Tomography, May 2018, Salt Lake City, United States. pp.314-317 Communication dans un congrès hal-01745746v1
A Study on Convolution Operator Using Half Precision Floating Point Numbers on GPU for Radioastronomy Deconvolution Mickael Seznec,Nicolas Gac,André Ferrari,François Orieux IEEE International Workshop on Signal Processing Systems (SiPS 2018), Oct 2018, Le Cap, South Africa. ⟨10.1109/sips.2018.8598342⟩ Communication dans un congrès hal-01837982v1
Bayesian Inference with Error Variable Splitting and Sparsity Enforcing Priors for Linear Inverse Problems Ali Mohammad-Djafari,Mircea Dumitru,Camille Chapdelaine,Nicolas Gac 26th European Signal Processing Conference (EUSIPCO 2018), Sep 2018, Rome, Italy. ⟨10.23919/eusipco.2018.8553335⟩ Communication dans un congrès hal-01837986v1
Performance comparison of Bayesian iterative algorithms for three classes of sparsity enforcing priors with application in computed tomography Mircea Dumitru,Wang Li,Nicolas Gac,Ali Mohammad-Djafari 2017 IEEE International Conference on Image Processing, Sep 2017, Beijing, China Communication dans un congrès hal-01568337v1
Model selection in the sparsity context for inverse problems in Bayesian framework Mircea Dumitru,Li Wang,Ali Mohammad-Djafari,Nicolas Gac 37th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering, Jul 2017, Jarinu, Brazil. ⟨10.1007/978-3-319-91143-4_15⟩ Communication dans un congrès hal-01568318v1
Unsupervised sparsity enforcing iterative algorithms for 3D image reconstruction in X-ray computed tomography Mircea Dumitru,Nicolas Gac,Li Wang,Ali Mohammad-Djafari The 2017 International Conference on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, Jun 2017, Xi'an, China. pp.359-362 Communication dans un congrès hal-01568325v1
3D Tomography parallelization on FPGAs via HLS tools Maxime Martelli,Nicolas Gac,Alain Mérigot,Cyrille Enderli DASIP, Sep 2017, dresden, Germany. pp.1-6, ⟨10.1109/DASIP.2017.8122119⟩ Communication dans un congrès hal-01569320v1
Reconstruction 3D en tomographie à rayons X à l'aide d'un modèle a priori hiérarchique utilisant la transformation de Haar Li Wang,Nicolas Gac,Ali Mohammad-Djafari 26eme Colloque GRETSI Traitement du Signal & des Images, GRETSI 2017, Sep 2017, Juan-Les-Pins, France Communication dans un congrès hal-01567888v1
Bayesian X-ray Computed Tomography using a Three-level Hierarchical Prior Model Li Wang,Ali Mohammad-Djafari,Nicolas Gac AIP Conference, Bayesian inference and maximum entropy methods in science and engineering (Maxent 2016), Jul 2016, Gent, Belgium. ⟨10.1063/1.4985361⟩ Communication dans un congrès hal-01403790v1
Joint Reconstruction and Segmentation of Real 3D Data in Computed Tomography thanks to a Gauss-Markov-Potts Prior Model, Camille Chapdelaine,Ali Mohammad-Djafari,Nicolas Gac,Estelle Parra-Denis Fully 3D, Jun 2017, Xian, China. pp.810-813 Communication dans un congrès hal-01569301v1
A joint segmentation and reconstruction algorithm for 3D Bayesian Computed Tomography using Gaus-Markov-Potts Prior Model Camille Chapdelaine,Ali Mohammad-Djafari,Nicolas Gac,Estelle Parra-Denis The 42nd IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2017), Mar 2017, New Orleans, United States Communication dans un congrès hal-01588443v1
Comparaison des performances d’algorithmes itératifs bayésiens basés sur trois classes de modèles a priori parcimonieux appliqués à la reconstruction tomographique Mircea Dumitru,Li Wang,Nicolas Gac,Ali Mohammad-Djafari 26eme Colloque GRETSI Traitement du Signal & des Images, GRETSI 2017, Sep 2017, Juans-Les-Pins, France Communication dans un congrès hal-01569349v1
X-ray computed tomography simultaneous image reconstruction and contour detection using a hierarchical markovian model Li Wang,Ali Mohammad-Djafari,Nicolas Gac The 42nd IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2017), Mar 2017, New Orleans, United States. pp.6070-6074, ⟨10.1109/ICASSP.2017.7953322⟩ Communication dans un congrès hal-01490508v1
3D X-ray Computed Tomography reconstruction using sparsity enforcing Hierarchical Model based on Haar Transformation Li Wang,Ali Mohammad-Djafari,Nicolas Gac,Mircea Dumitru The 2017 International Conference on Fully Three-Dimensional Image Reconstruction in Radiology and Nuclear Medicine, Jun 2017, Xi'an, China. pp.295-298 Communication dans un congrès hal-01490554v1
Bayesian method with sparsity enforcing prior of dual-tree complex wavelet transform coefficients for X-ray CT image reconstruction Li Wang,Ali Mohammad-Djafari,Nicolas Gac 25th European Signal Processing Conference (EUSIPCO 2017), Aug 2017, Kos island, Greece. ⟨10.23919/eusipco.2017.8081253⟩ Communication dans un congrès hal-01567875v1
A Student-t based sparsity enforcing hierarchical prior for linear inverse problems and its efficient Bayesian computation for 2D and 3D Computed Tomography Ali Mohammad-Djafari,Li Wang,Nicolas Gac,Folkert Bleichrodt International traveling workshop on interactions between sparse models and technology, Aug 2016, AALBORG, Denmark Communication dans un congrès hal-01403787v1
Computed tomography reconstruction based on a hierarchical model and variational Bayesian method Li Wang,Ali Mohammad-Djafari,Nicolas Gac,Mircea Dumitru IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Mar 2016, Shanghai, China. pp.883-887, ⟨10.1109/ICASSP.2016.7471802⟩ Communication dans un congrès hal-01403784v1
A hierarchical variational Bayesian approximation approach in acoustic imaging Ning Chu,Ali Mohammad-Djafari,Nicolas Gac,José Picheral 34th International Workshop on Bayesian Inference and Maximun Entropy Methods in Science and Engineering (MaxEnt'14), Sep 2014, Amboise, France. pp.572 - 579, ⟨10.1063/1.4906024⟩ Communication dans un congrès hal-01103784v1
Bayesian 3D X-ray computed tomography image reconstruction with a scaled Gaussian mixture prior model Li Wang,Nicolas Gac,Ali Mohammad-Djafari 34th International Workshop on Bayesian Inference and Maximun Entropy Methods in Science and Engineering (MaxEnt'14), Sep 2014, Amboise, France. pp.556-563, ⟨10.1063/1.4906022⟩ Communication dans un congrès hal-01338706v1
A variational Bayesian approximation approach via a sparsity enforcing prior in acoustic imaging Ning Chu,Ali Mohammad-Djafari,Nicolas Gac,José Picheral WIO 2014, Jul 2014, Neuchâtel, Switzerland. pp.1 - 4, ⟨10.1109/WIO.2014.6933297⟩ Communication dans un congrès hal-01103751v1
Aero-acoustics source separation with sparsity inducing priors in the frequency domain Olivier Schwander,José Picheral,Nicolas Gac,Ali-Mohammad Djafari,Daniel Blacodon 34th International Workshop on Bayesian Inference and Maximun Entropy Methods in Science and Engineering (MaxEnt'14), Sep 2014, Amboise, France. pp.422 - 431, ⟨10.1063/1.4906006⟩ Communication dans un congrès hal-01103779v1
Convolution Models with Shift-invariant kernel based on Matlab-GPU platform for Fast Acoustic Imaging Ning Chu,Nicolas Gac,José Picheral,Ali Mohammad-Djafari ISAV 2014, Dec 2014, Tehran, Iran Communication dans un congrès hal-01103819v1
A simple and efficient super-short-scan algorithm of fan-beam reconstruction for multiple circular trajectories: solution towards the truncated data Long Chen,Thomas Rodet,Nicolas Gac The Third International Conference on Image Formation in X-Ray Computed Tomography , Jun 2014, Salt Lake City, United States. pp.212-215 Communication dans un congrès hal-01403846v1
2D convolution model using (in)variant kernels for fast acoustic imaging Ning Chu,Nicolas Gac,José Picheral,Ali Mohammad-Djafari 5 th Berlin Beamforming Conference 2014, Feb 2014, Berlin, Germany. 15 p Communication dans un congrès hal-01083451v1
Analytical model and spectral correction of vibration effects on Fourier transform spectrometer I. Shatalina,Frederic Schmidt,B. Saggin,Nicolas Gac,Matthieu Kowalskiet al. SPIE Remote sensing 2013, Sep 2013, Dresden, Germany. pp.88900S-88900S-9, ⟨10.1117/12.2028632⟩ Communication dans un congrès hal-00930996v1
A penalized weighted least-squares image reconstruction based on scatter correction methods for X-ray CT Long Chen,Thomas Rodet,Nicolas Gac 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference, Oct 2013, Seoul, South Korea. pp.2 Communication dans un congrès hal-00843508v1
High-Dimensional Range Profile Geometrical Visualization and Performance Estimation of Radar Target Classification via a Gaussian Mixture Model Thomas Boulay,Ali Mohammad-Djafari,Nicolas Gac,Julien Lagoutte Geometric Science of Information, Aug 2013, Paris, France. pp.829-836, ⟨10.1007/978-3-642-40020-9_93⟩ Communication dans un congrès hal-00931023v1
An efficient variational Bayesian inference approach via Studient's-t priors for acoustic imaging in colored noises Ning Chu,Ali Mohammad-Djafari,José Picheral,Nicolas Gac POMA - ICA 2013, Jun 2013, Montreal, Canada. 055031 (9p.) Communication dans un congrès hal-00865786v2
A Fuzzy-Logic based non cooperative target recognition Thomas Boulay,Julien Lagoutte,Ali Mohammad-Djafari,Nicolas Gac Signal Image Technology and Internet Based Systems 2012, Nov 2012, Naples, Italy. pp.410-145, ⟨10.1109/SITIS.2012.66⟩ Communication dans un congrès hal-00778560v1
Multi GPU parallelization of 3D bayesian CT algorithm and its application on real foam reonconstruction with incomplete data set Nicolas Gac,Alexandre Vabre,Ali Mohammad-Djafari Forum on recent developments in Volume Reconstruction techniques applied to 3D fluid and solid mechanics, Nov 2011, Poitiers, France. pp.35-38 Communication dans un congrès hal-00658653v1
Accélération sur serveur multi-GPUs de la reconstruction 3D d'une mousse de nickel par méthodes itératives algébriques régularisées Nicolas Gac,Alexandre Vabre,Ali Mohammad-Djafari,Fanny Buyens 23ème colloque GRETSI sur le traitement du signal et des images, Sep 2011, Bordeaux, France. pp.id455 Communication dans un congrès hal-00616941v1
Algorithmes de Reconnaissance Non Coopérative de Cibles et implémentation sur GPU Thomas Boulay,Nicolas Gac,Ali Mohammad-Djafari,Julien Lagoutte GRETSI, Sep 2011, Bordeaux, France. pp.ID146 Communication dans un congrès hal-00617103v1
GPU implementation of a 3D bayesian CT algorithm and its application on real foam reconstruction Nicolas Gac,Alexandre Vabre,Ali Mohammad-Djafari,Asier Rabanal,Fanny Buyens The First International Conference on Image Formation in X-Ray Computed Tomography, Jun 2010, Salt Lake City, United States. pp.151-155 Communication dans un congrès hal-00504740v2
Parallélisation sur GPU d'un algorithme de reconstruction 3D bayésien en tomographie X. Nicolas Gac,Alexandre Vabre,Ali Mohammad-Djafari,Fanny Buyens,Samuel Legoupil Développement d'applications de calcul intensif sur carte graphique pour l'imagerie moléculaire, May 2009, Obernai, France Communication dans un congrès hal-00504759v1
A Hardware Projector/Backprojector Pair for 3D PET Reconstruction Nicolas Gac,Stéphane Mancini,Michel Desvignes,Florian de Boissieu,Anthonin Reilhac SPIE Medical Imaging 2008, Feb 2008, San Diego, Californie, United States. pp.69132O, ⟨10.1117/12.770588⟩ Communication dans un congrès hal-00232621v1
Algorithm Architecture Adequacy for High Speed 3D Tomography Nicolas Gac,Stéphane Mancini,Michel Desvignes,Dominique Houzet DASIP 2007 - Workshop on Design and Architectures for Signal and Image Processing, Nov 2007, Grenoble, France Communication dans un congrès hal-00175732v1
Hardware/software 2D-3D backprojection on a SoPC platform Nicolas Gac,Stéphane Mancini,Michel Desvignes ACM Symposium on Applied Computing, Apr 2006, Dijon, France. pp.222 - 228 Communication dans un congrès hal-00102903v1
Etude d'un cache 2D adaptatif et prédictif pour le traitement d'image Stéphane Mancini,Nicolas Gac,Michel Desvignes Journées Francophones en Adéquation Algorithme Architecture, Jan 2005, Dijon, France. pp.JFAAA 2005 Communication dans un congrès hal-00102913v1
Detection and Speech/Sound Segmentation in a Smart Room Environment Michel Vacher,Dan Istrate,Jean-François Serignat,Nicolas Gac Trends in Speech Technology, The 3rd International Conference on Speech Technology and Human-Computer Dialogue, IEEE, SpeD2005, May 2005, Cluj, Romania Communication dans un congrès hal-01092602v1
Rétroprojection 2D sur plateforme SOPC Stéphane Mancini,Nicolas Gac,Michel Desvignes GRETSI 2005 - 20ème colloque GRETSI sur le Traitement du Signal et des Images, GRETSI 2005, Sep 2005, Louvain-la-Neuve, Belgique. pp.783-786 Communication dans un congrès hal-00102907v1
2D backprojection on a SOPC platform : first results Stéphane Mancini,Nicolas Gac,Michel Desvignes 13 ème Forum Recherche en Génie Biologique et Médica, 2005, Nancy, France Communication dans un congrès hal-00102911v1

Poster de conférence (9)

SimSDP, a Rapid Prototyping tool for Radio Astronomy: From NenuFAR Experiments to SKAO-Scale Simulation Ophélie Renaud,Nicolas Gac,François Orieux,Cedric Dumez-Viou SaLF 2025 - 11th Annual conference on Science At Low Frequencies, Dec 2025, Orleans (France), France. pp.1-1 Poster de conférence hal-05406207v1
Fast Sky to Sky Interpolation for Radio Interferometric Imaging Nicolas Monnier,François Orieux,Nicolas Gac,Cyril Tasse,Erwan Raffinet al. 29th IEEE International Conference on Image Processing (ICIP 2022), Oct 2022, Bordeaux, France. IEEE, 2022 IEEE International Conference on Image Processing (ICIP), 2022, ⟨10.1109/ICIP46576.2022.9897317⟩ Poster de conférence hal-04696638v1
Les télélescopes SKA Nicolas Monnier,Nicolas Gac,François Orieux Fête de la science, Oct 2022, Saclay, France. Poster de conférence hal-03825850v1
Dataflow Algorithm aRchitecture co-design of SKA pipeline for Exascale Radio Astronomy Daniel Charlet,Karol Desnos,Mickaël Dardaillon,André Ferrari,Chiara Ferrariet al. ISC High Performance 2021, Jun 2021, Virtual conference, France. pp.1 Poster de conférence hal-03233205v2
A new convolutions algorithm to leverage tensor cores Mickael Seznec,Nicolas Gac,F. Orieux,A. Sashala Naik GPU Technology Conference (GTC), May 2020, Silicon Valley, United States Poster de conférence hal-02605077v1
An OpenCL design for tomographic reconstruction on FPGA. Innovate Europe Design Contest Winners Maxime Martelli,Mickael Seznec,Nicolas Heemeryck,Nicolas Gac 27th international conference on field programmable logic and applications, Sep 2017, Ghent, Belgium. 2017 Poster de conférence hal-01851828v1
Parallelization on a 8-GPU server of iterative 3D reconstruction algorithm for dental X-ray tomography Long Chen,Nicolas Gac,Thomas Rodet,Colombe Maury PUMPS summer school, Jul 2012, Barcelone, Spain Poster de conférence hal-01851992v1
Implémentation et optimisation du calcul sur GPUs FERMI et non FERMI de la distance euclidienne entre des profils distance obtenus à partir de données radar dans le contexte NCTR Thomas Boulay,Nicolas Gac,Ali Mohammad-Djafari,Julien Lagoutte Ecole d’été GPU, Jun 2011, Grenoble, France Poster de conférence hal-01851986v1
[OMTE 2008/2009] GPU speed-up of a 3D Bayesian CT algorithm : reconstruction of a real foam Nicolas Gac,Asier Rabanal,Alexandre Vabre,Ali Mohammad-Djafari Forum Digiteo, Oct 2010, Palaiseau, France Poster de conférence hal-01851994v1

Logiciel (4)

TomoGPI - accélérations sur GPU / FPGA de codes de reconstruction tomographique Nicolas Gac,Daouda Diakite,Mohammad-Djafari Ali 2022, ⟨swh:1:dir:439c43cac3a180dcdcc5430ec7a3b52a377689d2;origin=https://hal.archives-ouvertes.fr/hal-03947405;visit=swh:1:snp:1e5726ce9d93cc972235adbf62e32703d874c8ba;anchor=swh:1:rel:444d831c41a84c68a98117f8e61ebb21042bfa4f;path=/⟩ Logiciel hal-03947405v1
TomoBayes - logiciel de reconstruction en tomographie CT Camille Chapdelaine,Nicolas Gac,Thomas Boulay,Ali Mohammad-Djafari,Estelle Parra-Deniset al. 2019 Logiciel hal-01771489v1
iterTomoGPI-GPL - Ref CNRS du pré-dépôt APP 11562-02 (num IDDN prochainement disponible) Mircea Dumitru,Li Wang,Nicolas Gac,Ali Mohammad-Djafari 2018 Logiciel hal-01759762v1
opgpuTomoGPI - Ref CNRS du pré-dépôt APP 11562-01 (num IDDN prochainement disponible) Nicolas Gac,Ali-Mohammad Djafari 2014 Logiciel hal-01759782v1

Brevet (1)

Procédé et dispositif de contrôle non-destructif d'une pièce Camille Chapdelaine,Ali Mohammad-Djafari,Estelle Parra-Denis,Nicolas Gac France, N° de brevet: 18/53648. 2018 Brevet hal-01788556v1

Ouvrages (1)

French SKA White Book - The French Community towards the Square Kilometre Array F. Acero,J. -T. Acquaviva,R. Adam,N. Aghanim,Mark G. Allenet al. C. Ferrari; G. Lagache; M.-A. Miville-Deschenes; L. Montier; E. Josselin; N. Vilmer; P. Zarka; S. Corbel; S. Vergani; S. Lambert; G. Theureau; S. Bosse; A. Ferrari; S. Gauffre; G. Marquette; J.-M. Martin; B. Semelin; M. Alves; K. Ferrière. 2018, ⟨10.48550/arXiv.1712.06950⟩ Ouvrages hal-01686223v1