9 research outputs found

    An adaptive method for video denoising based on the ICI rule

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    This paper presents an adaptive video denoising technique based on the intersection of confidence intervals (ICI) rule used for adaptive filter support size calculation. The method is applied to three real-life video signals and its denoising performance is compared to a fixed size filter support based method resulting in a significant estimation error reduction in terms of the average frame peak signal-to-noise ratio (PSNR) improvement. The average frame PSNR obtained by using the here presented ICI based video denoising method is increased by up to 14.64 dB and by up to 23.74 dB when compared to the fixed size filter support based method. Furthermore, unlike the fixed size filter support based method, the adaptive ICI based method is shown to be efficient in a moving object edge preserving, while avoiding its blurring. The method performs well for both video signals obtained by recording stationary scenes, and video signals of moving objects, which are far more often encountered in practical applications, whereas the fixed size filter support based method is limited only to video signals of stationary scenes

    Multiresolution models in image restoration and reconstruction with medical and other applications

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    Intelligent Circuits and Systems

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    ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.  This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering

    Statistical signal processing for echo signals from ultrasound linear and nonlinear scatterers

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    Modelling, Simulation and Data Analysis in Acoustical Problems

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    Modelling and simulation in acoustics is currently gaining importance. In fact, with the development and improvement of innovative computational techniques and with the growing need for predictive models, an impressive boost has been observed in several research and application areas, such as noise control, indoor acoustics, and industrial applications. This led us to the proposal of a special issue about “Modelling, Simulation and Data Analysis in Acoustical Problems”, as we believe in the importance of these topics in modern acoustics’ studies. In total, 81 papers were submitted and 33 of them were published, with an acceptance rate of 37.5%. According to the number of papers submitted, it can be affirmed that this is a trending topic in the scientific and academic community and this special issue will try to provide a future reference for the research that will be developed in coming years

    Comportement vibratoire de rotors opérant à hautes vitesses et détection des défauts de roulements

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    L’objectif principal de cette thĂšse est l’étude du comportement dynamique des broches de machines-outils tournant Ă  hautes vitesses et le diagnostic des roulements qui leurs servent de support. L’analyse dynamique des broches est faite en utilisant un modĂšle numĂ©rique composĂ© d’un rotor et deux paliers de roulements. Elle offre la possibilitĂ© de voir l’influence de l’effet gyroscopique survenant Ă  haute vitesse sur les frĂ©quences naturelles du systĂšme. Les dĂ©veloppements rĂ©alisĂ©s permettent une meilleure comprĂ©hension de la dynamique des broches d’usinage tournant Ă  haute vitesse et permettent de corriger les limites des zones de stabilitĂ© des paramĂštres de coupe, lorsque la machine opĂšre Ă  haute vitesse. Cette modĂ©lisation a permis la mise au point d’un simulateur numĂ©rique du comportement vibratoire des broches considĂ©rant d’un cĂŽtĂ© les phĂ©nomĂšnes non linĂ©aires reliĂ©s Ă  la haute vitesse et d’un autre cĂŽtĂ©, les dĂ©fauts de roulements. Il est aussi dĂ©montrĂ© au travers de l’analyse expĂ©rimentale que les centres d’usinage Ă  hautes vitesses ne sont pas des machines tournantes conventionnelles et qu’un diagnostic fiable devra intĂ©grer dans le processus de dĂ©cision non seulement les indicateurs de vibration, mais aussi les conditions de coupe. Dans ce sens, cette thĂšse prĂ©sente un outil expĂ©rimental original de surveillance des machines-outils combinant la mesure des vibrations couplĂ©e avec les paramĂštres de fonctionnement (positions XYZ, vitesse instantanĂ©e, vitesse d’avance, outil en cours, puissance instantanĂ©e
) recueillis en temps rĂ©el grĂące Ă  un protocole de communication avec le contrĂŽleur de la machine. Cette thĂšse est rĂ©digĂ©e dans un format par articles, dans lequel 3 articles y seront prĂ©sentĂ©s. Le premier article, publiĂ© dans la revue International Journal of COMADEM prĂ©sente un nouvel outil de diagnostic automatisĂ© des dĂ©fauts de roulements, appelĂ© «Envelop Shock Detector (ESD) », destinĂ© Ă  dĂ©tecter, filtrer et extraire les chocs provoquĂ©s par les roulements dans le domaine temporel, puis Ă  les isoler des autres composantes harmoniques et alĂ©atoires. L’ESD est appliquĂ© comme outil de dĂ©bruitage-filtrage temporel pour Ă©liminer les composantes alĂ©atoires et harmonique du signal vibratoire, et pour distinguer les dĂ©fauts de roulements de ceux provoquĂ©s par les engrenages par le calcul d’un paramĂštre de glissement. Le mĂȘme outil pourrait ĂȘtre utilisĂ© comme paramĂštre d’entrĂ©e d’un rĂ©seau de neurones pour amĂ©liorer ses performances de dĂ©tection et sĂ©paration en cas de dĂ©fauts multiples provenant d’un mĂȘme roulement. Le deuxiĂšme article publiĂ© dans la revue sur l’ingĂ©nierie des risques industriels (JI-IRI), prĂ©sente un simulateur numĂ©rique basĂ© sur un modĂšle tridimensionnel Ă  20 degrĂ©s de libertĂ© incluant l’effet gyroscopique et permettant de simuler le fonctionnement en rĂ©gime transitoire -montĂ©es et descentes en vitesse- des broches de centre d’usinage, en prĂ©sence de dĂ©faut de roulements. Le simulateur permet de dĂ©celer l’apparition de nouvelles frĂ©quences critiques, hautement nuisibles pour la qualitĂ© d’usinage et surtout pour la durĂ©e de vie de l’équipement. Ces nuisances sont dues Ă  la coĂŻncidence entre les frĂ©quences d’excitation et celles dues aux dĂ©fauts de roulements avec les frĂ©quences naturelles du rotor, en modes de prĂ©cession avant et arriĂšre, ainsi qu’aux frĂ©quences du variateur de vitesse de la machine-outil. Le troisiĂšme article, soumis pour publication dans la revue internationale Machines traite de l’influence de la vitesse de rotation sur les paramĂštres dynamiques des broches et de la transmissibilitĂ© des vibrations provenant d’un roulement dĂ©fectueux au reste de la broche. De nouvelles frĂ©quences naturelles apparaissent et varient avec la vitesse. Les diagrammes de stabilitĂ©, utilisant les frĂ©quences naturelles Ă  l’arrĂȘt, deviennent pĂ©rimĂ©s et ne sont plus reprĂ©sentatifs du comportement vibratoire rĂ©el du systĂšme mĂ©canique. L’originalitĂ© dans cet article provient de l’ajout de l’effet gyroscopique pour tracer de nouveaux lobes de stabilitĂ© d’usinage et pour Ă©tudier la dĂ©rive des frĂ©quences naturelles Ă  haute vitesse. Les thĂ©ories avancĂ©es sont validĂ©es grĂące Ă  des essais de mesures vibratoires sur la machine-outil Huron opĂ©rant Ă  24,000 tours par minute

    Proceedings of the ECCOMAS Thematic Conference on Multibody Dynamics 2015

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    This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat Politùcnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: ● Formulations and Numerical Methods ● Efficient Methods and Real-Time Applications ● Flexible Multibody Dynamics ● Contact Dynamics and Constraints ● Multiphysics and Coupled Problems ● Control and Optimization ● Software Development and Computer Technology ● Aerospace and Maritime Applications ● Biomechanics ● Railroad Vehicle Dynamics ● Road Vehicle Dynamics ● Robotics ● Benchmark ProblemsPostprint (published version

    Multibody dynamics 2015

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    This volume contains the full papers accepted for presentation at the ECCOMAS Thematic Conference on Multibody Dynamics 2015 held in the Barcelona School of Industrial Engineering, Universitat PolitĂšcnica de Catalunya, on June 29 - July 2, 2015. The ECCOMAS Thematic Conference on Multibody Dynamics is an international meeting held once every two years in a European country. Continuing the very successful series of past conferences that have been organized in Lisbon (2003), Madrid (2005), Milan (2007), Warsaw (2009), Brussels (2011) and Zagreb (2013); this edition will once again serve as a meeting point for the international researchers, scientists and experts from academia, research laboratories and industry working in the area of multibody dynamics. Applications are related to many fields of contemporary engineering, such as vehicle and railway systems, aeronautical and space vehicles, robotic manipulators, mechatronic and autonomous systems, smart structures, biomechanical systems and nanotechnologies. The topics of the conference include, but are not restricted to: Formulations and Numerical Methods, Efficient Methods and Real-Time Applications, Flexible Multibody Dynamics, Contact Dynamics and Constraints, Multiphysics and Coupled Problems, Control and Optimization, Software Development and Computer Technology, Aerospace and Maritime Applications, Biomechanics, Railroad Vehicle Dynamics, Road Vehicle Dynamics, Robotics, Benchmark Problems. The conference is organized by the Department of Mechanical Engineering of the Universitat PolitĂšcnica de Catalunya (UPC) in Barcelona. The organizers would like to thank the authors for submitting their contributions, the keynote lecturers for accepting the invitation and for the quality of their talks, the awards and scientific committees for their support to the organization of the conference, and finally the topic organizers for reviewing all extended abstracts and selecting the awards nominees.Postprint (published version
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