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Abnormal event detection via the analysis of multi-frame optical flow information

1996 3rd International Conference on signal Processing(ICsP’96)

作者： Cedric RICHARD Regis LENGELLE Laboratoire lm2s Université de Technologie de Troyes10000 Troyes（France）

＜正＞Cohen’s class Time-Frequency Distributions （CTFDs） have significant potential for the analysis of non-stationary signals,even if the poor readability of their representations makes visual interpretations *** concentrate signal components,Auger and Flandrin generalized the reassignment method（first applied to the spectrogram） to any bilinear ***,this process is computationally *** order to quicken computation time and to improve representations readability,we first introduce a new fast algorithm which allows the recursive evaluation of classical spectrograms and spectrograms modified by the reassignment *** show that rectangular,half-sine, Hamming,Hanning and Blackmail functions can be used as running *** the previous algorithm is extended to *** show that the windows mentioned above can also be used to compute recursively reassigned smoothed pseudo Wigner-Ville ***,we show that the constraints on candidate windows are not very restrictive:any function（assumed periodic） can be used in practice as long as it admits a "short enough" Fourier series decomposition.

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Frontiers of Computer science 2020年第2期14卷 304-313页

作者： Tian WANG Meina QIAO Aichun ZHU Guangcun sHAN Hichem sNOUssI school of Automation science and Electrical Engineering Beihang UniversityBeijing 100191China school of Computer science and Technology Nanjing University of TechnologyNanjing 210094China school of Instrumentation science and Opto-electronics Engineering Beihang UniversityBeijing 100191China Institute Charles Delaunay-lm2s-UMR sTMR 6281 CNRs University of Technology of TroyesTroyes 10010France

security surveillance of public scene is closely relevant to routine safety of *** the stimulus of this concern,abnormal event detection is becoming one of the most important tasks in computer vision and video *** this paper,we propose a new algorithm to address the visual abnormal detection *** algorithm decouples the problem into a feature descriptor extraction process,followed by an AutoEncoder based network called cascade deep AutoEncoder(CDA).The movement information is represented by a novel descriptor capturing the multi-frame optical flow *** then,the feature descriptor of the normal samples is fed into the CDA network for ***,the abnormal samples are distinguished by the reconstruction error of the CDA in the testing *** validate the proposed method on several video surveillance datasets.

关键词： abnormal event detection multi-frame optical flow cascade deep autoencoder

ResLNet:deep residual LsTM network with longer input for action recognition

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Frontiers of Computer science 2022年第6期16卷 41-49页

作者： Tian WANG Jiakun LI Huai-Ning WU Ce LI Hichem sNOUssI Yang WU Institute of Artificial Intelligence Beihang UniversityBeijing100191China school of Automation science and Electrical Engineering Beihang UniversityBeijing100191China College of Electrical and Information Engineering Lanzhou University of TechnologyLanzhou730050China Institute Charles Delaunay-lm2s FRE CNRs 2019 University of Technology of TroyesTroyes10010France Institute for Research Initiatives Nara Institute of Science and TechnologyNara630-0192Japan

Action recognition is an important research topic in video analysis that remains very *** recognition relies on learning a good representation of both spatial information(for appearance)and temporal information(for motion).These two kinds of information are highly correlated but have quite different properties,leading to unsatisfying results of both connecting independent models(e.g.,CNN-LsTM)and direct unbiased co-modeling(e.g.,3DCNN).Besides,a long-lasting tradition on this task with deep learning models is to just use 8 or 16 consecutive frames as input,making it hard to extract discriminative motion *** this work,we propose a novel network structure called ResLNet(Deep Residual LsTM network),which can take longer inputs(e.g.,of 64 frames)and have convolutions collaborate with LsTM more effectively under the residual structure to learn better spatial-temporal representations than ever without the cost of extra computations with the proposed embedded variable stride *** superiority of this proposal and its ablation study are shown on the three most popular benchmark datasets:Kinetics,HMDB51,and *** proposed network could be adopted for various features,such as RGB and optical *** to the limitation of the computation power of our experiment equipment and the real-time requirement,the proposed network is tested on the RGB only and shows great performance.

关键词： action recognition deep learning neural network

Negative supracrystals inducing a FCC-BCC transition in gold nanocrystal superlattices

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Nano Research 2014年第2期7卷 171-179页

作者： Nicolas Goubet Universite Pierre et Marie Curie Paris 6 UMR 7070 LM2N BP 52 4 place Jussieu 75005 Paris France Centre National de la Recherche scientifique Unite Mixte de Recherche 7070 LM2N 4 place Jussieu 75005 Paris France

The growth of nanocrystal superlattices of 5 nm single domain Au nanocrystals at an air-toluene interface induces formation of well-defined thin films （300--400 nm） with large coherence lengths. High-resolution electron microscopy showed that polyhedral holes （negative supracrystal） were formed on the nanocrystal superlattice surface. Formation of negative supracrystals is attributed to inclusion in the superlattice of organic molecules （dodecanethiol）, which are present in concentrated zones at the air-toluene interface. The coexistence of two supracrystalline structures （bcc/fcc） is attributed to diffusion of dodecanethiol molecules resulting in a Bain deformation of the nanocrystal array.

关键词： Negative crystalBain transformation nanocrystal superlattice supracrystal gold nanocrystal self-assembly

Accelerating temporal action proposal generation via high performance computing

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Frontiers of Computer science 2022年第4期16卷 59-68页

作者： Tian Wang shiye Lei Youyou Jiang Choi Chang Hichem snoussi Guangcun shan Yao Fu Institute of Artificial Intelligence Beihang UniversityBeijing100191China school of Automation science and Electrical Engineering Beihang UniversityBeijing100191China school of software Tsinghua UniversityBeijing100084China Department of Computer Engineering Gachon UniversitySeongnam13120South Korea Institute Charles Delaunay-lm2s FRE CNRs 2019 University of Technology of TroyesTroyes10010France school of Instrumentation science and Opto-electronics Engineering Beihang UniversityBeijing100191China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun130033China

Temporal action proposal generation aims to output the starting and ending times of each potential action for long videos and often suffers from high computation *** address the issue,we propose a new temporal convolution network called Multipath Temporal ConvNet(MTCN).In our work,one novel high performance ring parallel architecture based is further introduced into temporal action proposal generation in order to respond to the requirements of large memory occupation and a large number of ***,the total data transmission is reduced by adding a connection between multiple-computing load in the newly developed *** to the traditional Parameter server architecture,our parallel architecture has higher efficiency on temporal action detection tasks with multiple *** conduct experiments on ActivityNet-1.3 and THUMOs14,where our method outperforms-other state-of-art temporal action detection methods with high recall and high temporal *** addition,a time metric is further proposed here to evaluate the speed performancein the distributed training process.

关键词： temporal convolution temporal action proposal generation deep learning

Phase Transformation in the Ball Milled Fe_(31)Co_(31)Nb_(8)B_(30) Powders

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Advances in Materials Physics and Chemistry 2013年第1期3卷 90-100页

作者： s.Azzaza s.Alleg J.J.sunol Laboratoire de Magnetisme et spectroscopie des solides(lm2s) Departement de PhysiqueFaculte des SciencesUniversite Badji MokhtarAnnabaAlgerie Department de Fisica Universitat de GironaGironaSpain

The mechanical alloying process has been used to prepare nanostructured Fe31Co31Nb8B30 (wt%) alloy from pure elemental powders in a high energy planetary ball-mill Retsch PM400. Microstructural changes, phase transformation and kinetics were studied by X-ray diffraction, differential scanning calorimetry and M?ssbauer spectrometry. The crystallite size reduction down the nanometer scale (~8 nm) is accompanied by the introduction of internal strains up to 1.8% (root-mean square strain, rms). Further milling time leads to the formation of partially paramagnetic amorphous structure in which bcc FeCo nanograins are embedded. The kinetics of amorphization during the milling process can be described by two regimes characterized by different values of the Avrami parameter n1 = 1.41 and n2 = 0.34. The excess enthalpy due to the high density of defects is released at temperatures below 300°C. The glass transition temperature increases with increasing milling time.

关键词： Nanomaterials Mechanical Alloying X-Ray Diffraction Fe-Co-Nb-B system Amorphization Kinetics

Boron-10 lined proportional counter development for thermal neutron detection

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Radiation Detection Technology and Methods 2021年第1期5卷 110-116页

作者： Mohamed Fares Mohamed Yacine Debili Mohammed Messaoudi samir Begaa Kassida Negara Adnane Messai Laboratory of Nuclear Detectors Department Detection and MeasurementNuclear Research Centre of BirineP.O.Box 18017200 Ain OusseraDjelfaAlgeria lm2s Physics DepartmentFaculty of ScienceBadji Mokhtar UniversityBP 1223200 AnnabaAlgeria Reactor Chemistry Department Nuclear Research Centre of BirineP.O.Box 18017200 Ain OusseraDjelfaAlgeria

Purpose Neutrons detection is of paramount importance in nuclear physics experiments,reactor physics,monitoring and control of nuclear reactors and in radiation *** the neutron detectors used are Proportional Counters(PC to BF3,boron deposition,3He),Our Detection and Measurements laboratory has embarked on a project to develop,design and build proportional counters with boron deposition mainly for gas filling,several prototypes of which have been *** This work presents the Boron-10 Lined Proportional Counters(PC),developed and produced in the Detection and Measurements Department(DDM19).The PC was designed by adopting,for the electrodes,a stainless steel cathode 0.5 mm thick and a gold-plated tungsten anode with diameter of 25μ*** detectors are filled with an Ar-CH4 mixture(10%)at a pressure of 20 *** boron deposition is performed by the technique of *** The results obtained using the DDM19 prototype PC(Detector produced in our Detection and Measurement laboratory,2019),show the advantage of electrophoresis as a better boron deposition technique,and the limitation of the surface mass of 10B to optimal values is around 0.5 at 0.6 mg/*** The characteristics of the gas amplification in the mixture(Ar-CH4(CH410%)),were measured by different methods and compared with the values of the proportional reference counter *** counting plates for the two reference meters LND232 and our DDM19 prototype from 200 to 300 V have slopes ranging from 6.5 to 10%/100 V,and gas amplification factors from 1436 to 1380,respectively.

关键词： Neutron detector Boron-10 lined proportional counter Reference LND232 Boron deposition technique

^(3)He proportional counter development for thermal neutron detection

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Radiation Detection Technology and Methods 2021年第2期5卷 264-272页

作者： Mohamed Fares Adnane Messai samir Begaa Maameri salem Kassida Negara Mohamed Yacine Debili Mohammed Messaoudi Laboratory of Nuclear Detectors Department Detection and MeasurementNuclear Research Centre of BirineP.O.Box 18017200 Ain OusseraDjelfaAlgeria Reactor Chemistry Department Nuclear Research Centre of BirineP.O.Box 18017200 Ain OusseraDjelfaAlgeria lm2s Physics DepartmentFaculty of ScienceUniversity of Badji Mokhtar-AnnabaP.O.Box.BP 1223000 AnnabaAlgeria

Neutron detection is used in a wide range of applications in nuclear physics,radiation protection,nuclear fuel cycle,reactor instrumentation,security and industrial *** the detectors used in this field,we notice the gas-filled 3He proportional counters which have been one of the main detecting tools for thermal and cold neutron detection for many *** last characteristic has ensured that this detector is one of the best tools for thermal neutron flux measurements in a nuclear reactor *** the instrumentation and detection laboratory of the Nuclear Research Center,of Birine,we are working toward the design and the development of this type of detectors,indeed,several prototypes of neutron detectors have been realized including the 3He proportional *** this paper,we will present the experimental steps and the obtained results to carry out a 3He proportional counter prototype that was fully developed and tested in our laboratory.A comparison study was made between our detector and a commercial cylindrical 3He neutron detector which was considered in this work as a reference detector:LND252(3He)-*** results showed that the characteristics of the gas amplification and the counting plateau for the two counters reference LND 252(3He)-PC and our prototype was of the same order of *** experimental tests show that our developed prototype perfect fit with the standard International Electrotechnical Commission(IEC,***)in the operating principle,the technology adopted and obtained technical specifications.

关键词： Neutrons detectors 3He proportional counters Counting plateau Discrimination Gas amplification

Development of self-powered neutron detectors used in nuclear medicine for the measurement of neutron flows during treatment of boron neutron therapy

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Radiation Detection Technology and Methods 2021年第3期5卷 459-465页

作者： Mohamed Fares Adnane Messai salem Mameri Mohammed Messaoudi Mohamed Yacine Debili Hebboul Nourddine Kassida Negara Begaa samir Laboratory of Nuclear Detectors Department Detection and MeasurementNuclear Research Centre of BirineAin OusseraP.O.Box 18017200 DjelfaAlgeria Reactor Chemistry Department Nuclear Research Centre of BirineAin OusseraP.O.Box 18017200 DjelfaAlgeria lm2s Physics DepartmentFaculty of ScienceUniversity of Badji Mokhtar-AnnabaP.O.Box.BP 1223000 AnnabaAlgeria

Purpose The self Powered Neutrons Detectors(sPND)have the advantage of not requiring a high voltage power supply for their operation and are small in size,enhancing the interest of these detectors in *** In this context,we have developed a thermal neutron detection system based on *** detector was placed in the thermal channel of our nuclear research reactor;where the values of the current for each detector have been recorded as a function of time,with a chain in a current mode where electrometers without HV were *** We performed the real-time measurement of neutron flux during boron neutron capture therapy or boron neutron therapy,the different materials constituting the sPND detectors have been carefully chosen for this *** detectors were tested at a power of four MW corresponding to a neutron flux of 10^(9) n cm^(−2) s^(−1).Conclusions The usefulness of 103Rh-sPND is for online measurement of thermal neutron flux on BNCT patients has been demonstrated based on an appropriate calibration of the thermal neutron spectrum.

关键词： sPND Thermal neutron Capture therapy Flux Detection Boron