175 results on '"National Aerospace"'
Search Results
2. Implementation of the method of boundary integral equations in boundary value problems of gasdynamics
- Author
-
Yuriy Aleksandrovich Krashanitsa; <em>National Aerospace University by it. N.E.Joukowsky «KHAI»</em>, A Hoshmandi; <em>National Aerospace University by it. N.E.Joukowsky «KHAI»</em>, N Hristenko; <em>National Aerospace University by it. N.E.Joukowsky «KHAI»</em>, Yuriy Aleksandrovich Krashanitsa; <em>National Aerospace University by it. N.E.Joukowsky «KHAI»</em>, A Hoshmandi; <em>National Aerospace University by it. N.E.Joukowsky «KHAI»</em>, and N Hristenko; <em>National Aerospace University by it. N.E.Joukowsky «KHAI»</em> more...
- Published
- 2018
Catalog
3. Computer simulation techniques for solving the tasks of optimal design of aerospace composite structures
- Author
-
Andrii Kondratiev; <p><span style="font-family: Times New Roman; font-size: medium;">National Aerospace University “Kharkiv Aviation Institute”</span></p> and Andrii Kondratiev; <p><span style="font-family: Times New Roman; font-size: medium;">National Aerospace University “Kharkiv Aviation Institute”</span></p> more...
- Published
- 2018
4. Metropolis II: Benefits of Centralised Separation Management in High-Density Urban Airspace
- Author
-
Morfin Veytia, Andres, Badea, Calin Andrei, Ellerbroek, Joost, Hoekstra, Jacco, Patrinopoulou, Niki, Daramouskas, Ioannis, Lappas, Vaios, Kostopoulos, V., De Vries, V., van Ham, Jacomijn, Sunil, Emmanuel, Menendez Ponte Alonso, P., Terrazas, J. Rodrigo Villazon, Bereziat, Denis, Vidosavljevic, Andrija, Sedov, Leonid, Delft University of Technology (TU Delft), University of Patras, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, NTT DATA, ENAC - Equipe Optim (OPTIM), Ecole Nationale de l'Aviation Civile (ENAC), Linköping University (LIU), SJU, and European Project: 892928,Metropolis II more...
- Subjects
UTM ,U-space ,Self-Separation ,Conflict Detection & Resolution (CD&R) ,Unmanned Traffic Management ,UAS ,[MATH]Mathematics [math] - Abstract
International audience; The Metropolis II project aimed to study the impact of centralised separation management for urban aerial mobility. Three concepts were developed in this study: a fully centralised, strategically separated concept, a hybrid concept featuring centralised strategic separation and distributed tactical separation, and a fully distributed tactical concept. A comparative simulation study was performed, using traffic scenarios based on predicted demand in an urban airspace in the city of Vienna. Simulations were performed with varying traffic densities and situations. Results show that the purely strategic and purely tactical strategies perform comparably in terms of safety, and that further improvements can be achieved with a combination of those strategies. more...
- Published
- 2022
5. Metropolis II: Investigating the Future Shape of Air Traffic Control in Highly Dense Urban Airspace
- Author
-
Patrinopoulou, N., Daramouskas, I., Lappas, V., Kostopoulos, V., Veytia, A. M., Badea, C. A., Ellerbroek, J., Hoekstra, J., de Vries, V., van Ham, J., Sunil, E., Ponte Alonso, P. Menendez, Pedrero Gonzalez, J., Bereziat, D., Vidosavljevic, A., Sedov, L., University of Patras, Delft University of Technology (TU Delft), National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, NTT DATA, Laboratoire de recherche ENAC (ENAC-LAB), Ecole Nationale de l'Aviation Civile (ENAC), Linköping University (LIU), and European Project: 892928,M2 more...
- Subjects
BlueSky ATC Simulator ,Unmanned Traffic Management (UTM) ,[SPI]Engineering Sciences [physics] ,Separation management ,Urban Airspace ,Flight planning ,U-Space ,Degree of Centralisation - Abstract
International audience; Metropolis II aims to provide insights in what is needed to enable high-density urban air operations. It does this by investigating the foundation for U-space U3/U4 services. The final goal is to provide a unified approach for strategic deconfliction, tactical deconfliction, and dynamic capacity management. Highly-dense operations in constrained urban airspace will likely require a degree of complexity that does not exist in modern-day air traffic management. The expected high traffic demand will require a shared use of the airspace instead of assigning exclusive use of blocks of the airspace to some flights. A unified approach for traffic management is needed because at high-densities, airspace design, flight planning, and separation management become increasingly interdependent. Metropolis II builds upon the results of the first Metropolis project. Three concepts with a varying degree of centralisation will be compared using simulations. (1) The centralised concept will take a global approach for separation management. (2) The decentralised concept aims to give the individual agents separation responsibility. (3) The hybrid concept tries to combine a centralised strategic planning agent with a robust tactical separation strategy. more...
- Published
- 2022
- Full Text
- View/download PDF
6. Evaluation of acoustic shielding effects from a generic GARTEUR helicopter configuration
- Author
-
Yin, Jianping, Rossignol, Karl-Stéphane, Reboul, Gabriel, Mortain, Frédéric, Vigevano, Luigi, Zanotti, Alex, Barbarinot, Mattia, Testa, Claudio, Bernardini, Giovanni, Brouwer, Harry, Deutsches Zentrum für Luft- und Raumfahrt (DLR), DAAA, ONERA, Université Paris-Saclay [Châtillon], ONERA-Université Paris-Saclay, Politecnico di Milano [Milan] (POLIMI), CIRA, Italy, INSEAN - CNR, Consiglio Nazionale delle Ricerche [Roma] (CNR), Roma Tre University, National Aerospace Laboratory [Amsterdam] (NLR), and National Aerospace more...
- Subjects
[PHYS]Physics [physics] ,[SPI]Engineering Sciences [physics] ,BEM ,GARTEUR - Abstract
International audience; This paper presents the activities in the GARTEUR Action Group HC/AG-24 to study the noise scattering of helicopter rotors in the presence of the fuselage. The focus of the Action Group is on the development and the validation of numerical prediction methods and on establishing an experimental data base for numerical validations. This paper will focus on the results from the wind tunnel and the numerical activities achieved in the last stage of the project. Shielding experiments were conducted in DLR's Acoustic Wind tunnel in Braunschweig (AWB) using point and rotor noise sources. The numerical methods used in the group include Boundary Element Method (BEM) for solving the Helmholtz equation and Computational AeroAcoustic method (CAA) for solving the linearized Euler equations. The acoustic scattering predictions are compared to test data. more...
- Published
- 2021
7. Reducing Noise Impact and Improving Quality of Life by Addressing Annoyance
- Author
-
Aalmoes, Roalt, Bartels, Susanne, Benz, Sarah, Großarth, Stephan, Hauptvogel, Dominik, Haubrich, Julia, Heyes, Graeme, Hooper, Paul, Kotzinos, Dimitri, Kuhlmann, Julia, Müller, Uwe, Richard, Isabelle, Lavandier, Catherine, Ohlenforst, Barbara, Roosien, Rui, Márki, Ferenc, Quehl, Julia, Schreckenberg, Dirk, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), CY Cergy Paris Université (CY)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA), Budapest University of Technology and Economics [Budapest] (BME), ZEUS Consulting S.A., and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY) more...
- Subjects
[PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph] ,Quality of life ,Annoyance ,noise annoyance ,noise impact ,aircraft noise ,community engagement ,[PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph] - Abstract
Aircraft noise is the most significant impact on communities residing near airports. But in addition to acoustical factors, non-acoustical factors also contribute to noise annoyance. In the ANIMA project, relevant indicators influencing the quality of life of residents living near airport are identified. Literature studies, but also focus group meetings and workshops, and online survey for communities near altogether nine different European airports are performed to understand the role of the airport and the implications on the well-being of citizens. Furthermore, it is intended to study what current communication strategies of the airports are and how they influence the impact of aircraft noise on residents’ annoyance response and well-being. A detailed literature study as well as a re-analysis of data has been carried out to develop awakenings indicators for nocturnal fly-overs, as noise-induced sleep disturbance has been linked to adverse health effects and is also associated with annoyance. Another study will be conducted to understand human visual perception of aircraft and their noise levels using a noise simulator with Virtual Reality glasses, where different aircraft types and their noise impact will be compared in a laboratory study and later in an “in situ” experiment. Finally, people’s perception of environmental sound near the airport and the relation with land use planning will be evaluated by developing a mobile application to be used around Heathrow and Ljubljana Airport. Together with a carefully crafted social media study, data on property-value and movement of people throughout the day, we hope to establish more evidence on the relationship between land-use planning, noise perception and quality of life. The outcomes of all studies will be tested later in intervention studies and, or integrated into a Best-Practice portal that will be available for airports, governments, communities, and other stakeholders more...
- Published
- 2021
- Full Text
- View/download PDF
8. Virtual reality simulated aircraft flyovers: Influence of the landscape on the overall pleasantness of the environment
- Author
-
Roalt Aalmoes, Catherine Lavandier, Umberto Iemma, Ingrid LeGriffon, Henk Lania, Romain Dedieu, Isabelle Boullet, Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA), CY Cergy Paris Université (CY), National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, DAAA, ONERA, Université Paris-Saclay [Châtillon], ONERA-Université Paris-Saclay, Airbus Group, and Università degli Studi Roma Tre more...
- Subjects
[PHYS]Physics [physics] ,PERCEPTION ,Architectural engineering ,Computer science ,media_common.quotation_subject ,Frame (networking) ,Differential (mechanical device) ,Virtual reality ,[SPI]Engineering Sciences [physics] ,REALITE VIRTUELLE ,Perception ,ACOUSTIQUE ,Relevance (information retrieval) ,Laboratory experiment ,media_common - Abstract
To give residents better understanding of the impact of future airport scenarios, a virtual reality application with sound simulation will be tested in the frame of the European ANIMA project. The set-up has been evaluated in laboratory before being used in real situation. This paper presents the laboratory experiment whose aim is to assess the application’s relevance for simulating flyovers. Although the perceptual experiment is designed to test the influence of aircraft vision crossed with aircraft sound, this paper focusses only on the impact of the landscape where the flyovers are observed. Two landscapes (park and buildings) are presented to 60 participants, in balanced order, with 12 audio-visual stimuli in both landscapes. Participants had to rate four differential semanticscales. Globally there is no influence of the landscape on the overall pleasantness, but when looking at the individual answers, it appears that three groups of participants can be discriminated. The majority of people do not change their pleasantness ratings in both landscapes, but some participants prefer experiencing the flyovers in the park landscape because it is visually more pleasant, and others prefer the oppositebecause it is more annoying to be submitted to aircraft noise in a green park landscape more...
- Published
- 2021
- Full Text
- View/download PDF
9. Enhancing the handling qualities analysis by collaborative aerodynamics surrogate modelling and aero-data fusion
- Author
-
Mengmeng Zhang, Mark Voskuijl, Nathalie Bartoli, Erik Baalbergen, Wim Lammen, Aidan Jungo, AIRINNOVA AB, ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, CFS Engineering, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, Faculty of Aerospace Engineering [Delft], and Delft University of Technology (TU Delft) more...
- Subjects
Computer science ,media_common.quotation_subject ,Aerospace Engineering ,Fidelity ,surrogate-modeling ,02 engineering and technology ,01 natural sciences ,multi-fidelity analysis ,010305 fluids & plasmas ,Multidisciplinary design optimization ,AGILE ,[SPI]Engineering Sciences [physics] ,Surrogate model ,0203 mechanical engineering ,0103 physical sciences ,[MATH]Mathematics [math] ,media_common ,[PHYS]Physics [physics] ,020301 aerospace & aeronautics ,Iterative and incremental development ,aero-database ,Mechanical Engineering ,Control engineering ,Sensor fusion ,computational aerodynamics ,Data set ,Surrogate Model Repository ,Mechanics of Materials ,Data analysis ,Design process ,CPACS ,sampling approaches - Abstract
In the modern aircraft design process numerical simulation is one of the key enablers. However, computational time increases exponentially with the level of fidelity of the simulation. In the EU Horizon2020 project AGILE different aircraft design analysis tools relative to different levels of fidelity are used. One of the challenges is to reduce the computational time - e.g. to facilitate an efficient optimization process - by processing the analysis data of various fidelity levels in a global surrogate model. This paper focuses on fusion of data sets via an automatic iterative process embedded in the collaborative multidisciplinary analysis (MDA) chains as applied in AGILE. Surrogate modeling techniques are applied, taking into account the optimal sampling and the corresponding fidelities of the samples. This paper will detail the different steps of the proposed collaborative approach. As a test case handling qualities analysis of the AGILE reference conventional aircraft is performed, by fusing the computed aerodynamic coefficients and derivatives. A full set of aerodynamic data computed either with different levels of fidelity or with only a low-fidelity tool has been derived and evaluated. The data set with multiple levels of fidelity significantly improved the accuracy of the flight performance analysis, especially for the transonic region in which the low fidelity aerodynamic method is not reliable. Moreover, the test case shows that by combining a collaborative surrogate modeling approach with fusion of the data sets, the fidelity of the analysis data can be significantly improved giving maximum relative prediction error less than 5 % with minimal computing efforts. more...
- Published
- 2020
- Full Text
- View/download PDF
10. Optimal design, manufacturing and testing of non-conventional laminates
- Author
-
Roman Růžek, François-Xavier Irisarri, Daniël Peeters, Chris Groenendijk, ERC, Delft University of Technology (TU Delft), DMAS, ONERA, Université Paris Saclay (COmUE) [Châtillon], ONERA-Université Paris Saclay (COmUE), National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, and Czech Aerospace Research Centre (VZLU) more...
- Subjects
Optimal design ,Materials science ,ESSAI ,EPAISSEUR VARIABLE ,Variable thickness ,RIGIDITE VARIABLE ,02 engineering and technology ,variable stiffness ,fibre steering ,[SPI]Engineering Sciences [physics] ,fibre placement ,TESTING ,0203 mechanical engineering ,STEERING ,Fiber ,variable thickness ,Civil and Structural Engineering ,VARIABLE THICKNESS ,[PHYS]Physics [physics] ,Variable stiffness ,business.industry ,Fibre steering ,PLACEMENT DE FIBRE ,Work (physics) ,FIBRE PLACEMENT ,Structural engineering ,021001 nanoscience & nanotechnology ,Compression (physics) ,testing ,FIBRE CURVILIGNE ,020303 mechanical engineering & transports ,Buckling ,Ceramics and Composites ,Benchmark (computing) ,0210 nano-technology ,business ,VARIABLE STIFFNESS - Abstract
International audience; Composite materials are finding increasing application, for example in commercial aircraft. Traditionally fiber angles are restricted to 0 • , ±45 • and 90 •. The current work exploits the possibility of using multiple 'non-conventional' laminates where either fiber steering ('variable stiff-ness'), ply drops ('variable thickness'), or a combination of both is used. This leads to varying mechanical properties which means the load is being redistributed, increasing the overall buckling load. A flat panel of 400 × 600 mm loaded in uni-axial compression is optimized in the current work. As a benchmark a conventional laminate is used. The non-conventional laminates are 15% lighter to emphasize the possible weight savings. Only using variable stiffness or variable thickness is experimentally shown to not be sufficient to match the buckling load of the benchmark panel. However, using a combination of both, a 10% increase in the buckling load was found for a panel that is 15% lighter. This highlights the potential of non-conventional laminates. more...
- Published
- 2019
- Full Text
- View/download PDF
11. A clustered and surrogate-based MDA use case for MDO scenarios in AGILE project
- Author
-
I. van Gent, Z. Mengmeng, Marco Panzeri, Wim Lammen, T. Lefebre, Sylvain Dubreuil, Nathalie Bartoli, Riccardo Lombardi, Pier Davide Ciampa, ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, NOESIS Solutions, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, AIRINNOVA AB, Delft University of Technology (TU Delft), and Deutsches Zentrum für Luft- und Raumfahrt (DLR) more...
- Subjects
Optimization problem ,Computer science ,Time to market ,MDA ,Mathematical and computer sciences ,02 engineering and technology ,Aeronautics ,MDO ,MODELE DE SUBSTITUTION ,01 natural sciences ,010305 fluids & plasmas ,AGILE ,[SPI]Engineering Sciences [physics] ,0203 mechanical engineering ,Multidisciplinary approach ,0103 physical sciences ,[INFO]Computer Science [cs] ,[MATH]Mathematics [math] ,OPTIMIZATION ,[PHYS]Physics [physics] ,020301 aerospace & aeronautics ,MDO AGILE Surrogate ,Collaborative engineering ,business.industry ,OPTIMISATION ,Surrogate ,computer.file_format ,SURROGATE MODEL ,Workflow ,Systems engineering ,Benchmark (computing) ,Executable ,business ,computer ,Agile software development - Abstract
International audience; In this paper methodological investigations regarding an innovative Multidisciplinary Design and Optimization (MDO) approach for conceptual aircraft design are presented. These research activities are part of the ongoing EU-funded research project AGILE. The next generation of aircraft MDO processes is developed in AGILE, which targets significant reductions in aircraft development cost and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and recalls the achievements of the first year of activities where a reference distributed MDO system has been formulated, deployed and applied to the design and optimization of a reference conventional aircraft configuration. Then, investigations conducted in the second year are presented, all aiming at making the complex optimization workflows easier to handle, characterized by a high degree of discipline interdependencies, multi-level processes and multi-partner collaborative engineering activities. The paper focuses on an innovative approach in which knowledge-based engineering and collaborative engineering techniques are used to handle a complex aircraft design workflow. Surrogate models replacing clusters of analysis disciplines have been developed and applied to make workflow execution more efficient. The paper details the different steps of the developed approach to set up and operate this test case, involving a team of aircraft design and surrogate modelling specialists, and taking advantage of the AGILE MDO framework. To validate the approach, different executable workflows were generated automatically and used to efficiently compare different MDO formulations. The use of surrogate models for clusters of design competences have been proved to be efficient approach not only to decrease the computational time and also to benchmark different MDO formulations on a complex optimization problem.; Dans cet article, des investigations méthodologiques concernant une approche innovante de conception et d'optimisation multidisciplinaire (MDO) pour la conception avion sont présentées. Ces activités de recherche font partie du projet de recherche européen H2020 AGILE. La prochaine génération de processus MDO pour les avions est développée dans le projet AGILE, visant à réduire de manière significative les coûts de développement des avions et les délais de mise sur le marché, conduisant à des solutions moins chères et plus écologiques.Le document présente la structure du projet AGILE et rappelle les réalisations de la première année pendant laquelle un premier système MDO distribué a été formulé, déployé et appliqué à la conception et à l'optimisation d'une configuration d'avion classique de référence.Ensuite, les études menées durant la deuxième année du projet sont présentées, toutes visant à rendre les processus complexes d'optimisation plus faciles à manipuler tout en impliquant des modèles haute-fidélité, des interdépendances avec plusieurs niveaux et des activités d'ingénierie collaborative entre les différents partenaires du projet.Le document se concentre sur une approche innovante dans laquelle l'ingénierie basée sur la connaissance et les techniques collaboratives sont utilisées pour gérer ces différents échanges.Des modèles de substitution remplaçant des clusters de disciplines ont été développés et appliqués pour rendre l'exécution du processus plus efficace. L'article détaille les différentes étapes de l'approche développée pour mettre en place et exploiter ce cas test, impliquant une équipe d‘experts de la conception avion et des modèles de substitution tout en tirant parti du cadre MDO du projet AGILE. Pour valider l'approche, différents exécutables ont été générés automatiquement et utilisés pour comparer efficacement différentes formulations MDO. L'utilisation des modèles de substitution pour des clusters de disciplines s'est révélée être une approche efficace non seulement pour réduire le temps de calcul, mais aussi pour comparer différentes formulations de MDO sur un problème d'optimisation complexe. more...
- Published
- 2020
- Full Text
- View/download PDF
12. Fusion de données et modèle réduite aérodynamique pour l’analyse des qualités de vol
- Author
-
Zhang, Mengmeng, Bartoli, Nathalie, Jungo, Aidan, Lammen, Wim, Baalbergen, Erik, Voskuijl, Mark, AIRINNOVA AB, ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, CFS Engineering, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, Faculty of Aerospace Engineering [Delft], and Delft University of Technology (TU Delft) more...
- Subjects
METAMODELE ,[PHYS]Physics [physics] ,[SPI]Engineering Sciences [physics] ,FUSION DONNEES ,MULTI-FIDELITE ,[INFO]Computer Science [cs] ,DATA FUSION ,[MATH]Mathematics [math] ,MODELE REDUIT ,SURROGATE MODEL ,MULTI-FIDELITY - Abstract
In the modern aircraft design process numerical simulation is one of the key enablers. However, computational time increases exponentially with the level of fidelity of the simulation. In the EU Horizon 2020 project AGILE different computation tools relative to different levels of fidelity are used. One of the challenges is to reduce the computational time - e.g. to facilitate an efficient optimization process - by processing the analysis data of various fidelity levels in a global surrogate model. This paper focuses on data fusion via an automatic iterative process embedded in the MDA chains as applied in AGILE. Surrogate modeling techniques are applied, taking into account the optimal sampling and the corresponding fidelities of the samples. This paper will detail the different steps of the proposed approach. As a test case handling qualities analysis of the AGILE reference conventional aircraft is performed, by fusing the computed aerodynamic coefficients and derivatives. A full spreadsheet of aerodynamic data computed either with different levels of fidelity or with only a low-fidelity tool has been derived and evaluated. By applying the data set with multiple levels of fidelity, the accuracy of the flight performance analysis was significantly improved especially for the transonic region in which the low fidelity aerodynamic method is not reliable. Moreover, the test case shows that by using a surrogate model based data fusion technique, the fidelity of the analysis data can be significantly improved with maximum RMSE less than 5% with minimum computation effort.; Dans le processus de conception avion, la simulation numérique est un des points clé. Cependant, le temps de calcul augmente exponentiellement avec le niveau de fidélité de la simulation. Dans le projet européen H2020 AGILE, différents outils de calcul avec différents niveaux de fidélité sont utilisés. Un des principaux défis est de réduire le temps de calcul - par exemple pour accélérer un processus d'optimisation - en rassemblant les données d'analyse provenant des différents niveaux de fidélité dans un métamodèle global. Cet article se concentre sur la fusion de données via un processus automatique itératif au sein des chaînes d’analyse multidisciplinaire comme celles utilisés dans le projet AGILE. Les techniques des métamodèles sont appliquées, prenant en considération l'échantillonnage optimal et leur fidélité correspondante. Ce papier détaille les différentes étapes de l'approche proposée. L’analyse des qualités de vol sur l’avion de référence AGILE est utilisée comme cas test de validation de l’approche, en fusionnant les coefficients et les dérivés aérodynamiques calculés. Une table de données aérodynamiques calculées avec un ou plusieurs niveaux de fidélité est évaluée. En utilisant l'ensemble des données multifidélité, la précision sur l'évaluation des performances de vol a été sensiblement améliorée particulièrement pour la région transsonique pour laquelle la méthode aérodynamique de basse fidélité n'est pas fiable. D'ailleurs, le cas test prouve que l’utilisation d’un métamodèle basé sur la fusion de donnée permet d’améliorer significativement la précision. more...
- Published
- 2020
13. Data Fusion and Aerodynamic Surrogate Modeling for Handling Qualities Analysis
- Author
-
Zhang, Mengmeng, Bartoli, Nathalie, Jungo, Aidan, Lammen, Wim, Baalbergen, Erik, Voskuijl, Mark, AIRINNOVA AB, ONERA / DTIS, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, CFS Engineering, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, Faculty of Aerospace Engineering [Delft], Delft University of Technology (TU Delft), and André, Cécile more...
- Subjects
[PHYS]Physics [physics] ,FUSION DONNEES ,[SPI] Engineering Sciences [physics] ,[MATH] Mathematics [math] ,[INFO] Computer Science [cs] ,MODELE REDUIT ,SURROGATE MODEL ,[PHYS] Physics [physics] ,METAMODELE ,[SPI]Engineering Sciences [physics] ,MULTI-FIDELITE ,[INFO]Computer Science [cs] ,DATA FUSION ,[MATH]Mathematics [math] ,MULTI-FIDELITY - Abstract
In the modern aircraft design process numerical simulation is one of the key enablers. However, computational time increases exponentially with the level of fidelity of the simulation. In the EU Horizon 2020 project AGILE different computation tools relative to different levels of fidelity are used. One of the challenges is to reduce the computational time - e.g. to facilitate an efficient optimization process - by processing the analysis data of various fidelity levels in a global surrogate model. This paper focuses on data fusion via an automatic iterative process embedded in the MDA chains as applied in AGILE. Surrogate modeling techniques are applied, taking into account the optimal sampling and the corresponding fidelities of the samples. This paper will detail the different steps of the proposed approach. As a test case handling qualities analysis of the AGILE reference conventional aircraft is performed, by fusing the computed aerodynamic coefficients and derivatives. A full spreadsheet of aerodynamic data computed either with different levels of fidelity or with only a low-fidelity tool has been derived and evaluated. By applying the data set with multiple levels of fidelity, the accuracy of the flight performance analysis was significantly improved especially for the transonic region in which the low fidelity aerodynamic method is not reliable. Moreover, the test case shows that by using a surrogate model based data fusion technique, the fidelity of the analysis data can be significantly improved with maximum RMSE less than 5% with minimum computation effort., Dans le processus de conception avion, la simulation numérique est un des points clé. Cependant, le temps de calcul augmente exponentiellement avec le niveau de fidélité de la simulation. Dans le projet européen H2020 AGILE, différents outils de calcul avec différents niveaux de fidélité sont utilisés. Un des principaux défis est de réduire le temps de calcul - par exemple pour accélérer un processus d'optimisation - en rassemblant les données d'analyse provenant des différents niveaux de fidélité dans un métamodèle global. Cet article se concentre sur la fusion de données via un processus automatique itératif au sein des chaînes d’analyse multidisciplinaire comme celles utilisés dans le projet AGILE. Les techniques des métamodèles sont appliquées, prenant en considération l'échantillonnage optimal et leur fidélité correspondante. Ce papier détaille les différentes étapes de l'approche proposée. L’analyse des qualités de vol sur l’avion de référence AGILE est utilisée comme cas test de validation de l’approche, en fusionnant les coefficients et les dérivés aérodynamiques calculés. Une table de données aérodynamiques calculées avec un ou plusieurs niveaux de fidélité est évaluée. En utilisant l'ensemble des données multifidélité, la précision sur l'évaluation des performances de vol a été sensiblement améliorée particulièrement pour la région transsonique pour laquelle la méthode aérodynamique de basse fidélité n'est pas fiable. D'ailleurs, le cas test prouve que l’utilisation d’un métamodèle basé sur la fusion de donnée permet d’améliorer significativement la précision. more...
- Published
- 2020
14. Wind turbine wakes and helicopter operations - An overview of the GARTEUR HC-AG23 activities
- Author
-
Bakker, R., Visingardi, A., Wall, B. G., Voutsinas, S., Basset, P. -M, Campagnolo, F., Pavel, M., George Barakos, White, M., National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, Centro Italiano Ricerche Aerospaziali (CIRA ), Agenzia Spaziale Italiana (ASI), German Aerospace Center (DLR), National Technical University of Athens [Athens] (NTUA), DTIS, ONERA [Salon], ONERA, TU-Munich, Delft University of Technology (TU Delft), University of Glasgow, and University of Liverpool more...
- Subjects
[PHYS]Physics [physics] ,[SPI]Engineering Sciences [physics] ,EOLIENNE ,DYNAMIQUE VOL ,[INFO]Computer Science [cs] ,[MATH]Mathematics [math] ,HELICOPTERE - Abstract
International audience; The effects of a wind turbine wake on General Aviation and the behaviour of helicopters in the tip vortex of large fixed-wing aircraft has been topic of research in the past years, but less is known about the interactions of helicopters operating in a wind turbine wake. A dedicated GARTEUR Action Group, HC-AG23, consisting of European universities and research institutes was formed to investigate helicopter behaviour in a wind tur-bine wake and to study the consequences for helicopter handling and safety of flight. The activities are struc-tured in work packages addressing wind turbine wake identification, wake experiments and computations, offline and piloted simulations and management and dissemination activities. This paper presents an over-view of the partners’ activities and provides a short overview of the results that have been achieved in the past three years.; Synthèse des activités du groupe GARTEUR HC-AG23 sur l'étude de la problématique du vol des hélicoptères dans le sillage des éoliennes more...
- Published
- 2018
15. MSE prediction in DCT-based lossy compression of noise-free and noisy remote sensing
- Author
-
Benoit Vozel, Mikhail Zriakhov, Vladimir V. Lukin, Sergey Krivenko, Kharkov National University, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Nantes Université (NU)-Université de Rennes 1 (UR1), National Aerospace University, Kharkov, Institut d'Electronique et de Télécommunications de Rennes ( IETR ), Université de Nantes ( UN ) -Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Institut National des Sciences Appliquées - Rennes ( INSA Rennes ) -CentraleSupélec-Centre National de la Recherche Scientifique ( CNRS ), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
Lossless compression ,Image coding ,Noise measurement ,Mean squared error ,Computer science ,[ INFO.INFO-NI ] Computer Science [cs]/Networking and Internet Architecture [cs.NI] ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,DCT ,MSE prediction ,Data_CODINGANDINFORMATIONTHEORY ,Lossy compression ,[ SPI.TRON ] Engineering Sciences [physics]/Electronics ,[SPI.TRON]Engineering Sciences [physics]/Electronics ,[INFO.INFO-NI]Computer Science [cs]/Networking and Internet Architecture [cs.NI] ,Discrete cosine transform ,Quantization (image processing) ,remote sensing images ,Dissemination ,Remote sensing - Abstract
International audience; Amount of remote sensing data rapidly increases. To transfer, store, and disseminate images, one has to apply compression. Lossless compression often does not satisfy requirements. In turn, lossy compression introduces distortions where their level should be controlled not to lose value of remote sensing data. In this paper, we propose a way to accurately predict mean square error of introduced distortions for DCT-based coder. Peculiarity of our approach is that prediction is considerably faster than compression. This allows estimating the introduced distortion level for a given quantization step and quick adjusting the quantization step. The proposed approach is applicable to both practically noise-free and noisy remote sensing images. © 2018 IEEE. more...
- Published
- 2018
- Full Text
- View/download PDF
16. Open-loop control of cavity noise using Proper Orthogonal Decomposition reduced-order model
- Author
-
Sintu Singha, Christophe Airiau, Laurent Cordier, Kaushik Kumar Nagarajan, Centre National de la Recherche Scientifique - CNRS (FRANCE), ISAE-ENSMA Ecole Nationale Supérieure de Mécanique et d'Aérotechnique (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Poitiers (FRANCE), CSIR-National Aerospace Laboratories - NAL (INDIA), Institut Recherche et Ingénierie en Matériaux, Mécanique et Energétique - Pprime (Chasseneuil-du-Poitou, France), National Aerospace Laboratories, Turbulence Incompressible et Contrôle (TIC ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Institut Pprime ( PPRIME ), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique ( CNRS ), Institut de mécanique des fluides de Toulouse ( IMFT ), Institut National Polytechnique [Toulouse] ( INP ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Ecole Nationale Supérieure de Mécanique et d'Aérotechnique - ENSMA (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
[ INFO.INFO-MO ] Computer Science [cs]/Modeling and Simulation ,General Computer Science ,Noise reduction ,Mécanique des fluides ,Proper Orthogonal Decomposition ,Boundary (topology) ,02 engineering and technology ,01 natural sciences ,MSC: 76N25, 76M30, 76Q05, 93A30 ,010305 fluids & plasmas ,Surrogate model ,0203 mechanical engineering ,Control theory ,0103 physical sciences ,Reduced-order modeling ,Upstream (networking) ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,Open cavity flow ,Mathematics ,General Engineering ,Open-loop controller ,[ PHYS.MECA.MEFL ] Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph] ,Optimal control ,Modélisation et simulation ,[INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation ,Noise ,020303 mechanical engineering & transports ,Stagnation enthalpy - Abstract
International audience; Flow over open cavities is mainly governed by a feedback mechanism due to the interaction of shear layer instabilities and acoustic forcing propagating upstream in the cavity. This phenomenon is known to lead to resonant tones that can reach 180 dB in the far-field and may cause structural fatigue issues and annoying noise emission. This paper concerns the use of optimal control theory for reducing the noise level emitted by the cavity. Boundary control is introduced at the cavity upstream corner as a normal velocity component. Model-based optimal control of cavity noise involves multiple simulations of the compressible Navier–Stokes equations and its adjoint, which makes it a computationally expensive optimization approach. To reduce the computational costs, we propose to use a reduced-order model (ROM) based on Proper Orthogonal Decomposition (POD) as a surrogate model of the forward simulation. For that, a control input separation method is first used to introduce explicitly the control effect in the model. Then, an accurate and robust POD ROM is derived by using an optimization-based identification procedure and generalized POD modes, respectively. Since the POD modes describe only velocities and speed of sound, we minimize a noise-related cost functional characteristic of the total enthalpy unsteadiness. After optimizing the control function with the reduced-order model, we verify the optimality of the solution using the original, high-fidelity model. A maximum noise reduction of 4.7 dB is reached in the cavity and up to 16 dB at the far-field. more...
- Published
- 2018
- Full Text
- View/download PDF
17. Wind turbine wakes and helicopter operations - An overview of the GARTEUR HC-AG23 activities
- Author
-
Bakker, Richard, Visingardi, Antonio, Van der Wall, Berend G., Voutsinas, Spyros, Basset, Pierre-Marie, Campagnolo, Filippo, PAVEL, Marilena, Barakos, Georges, White, Mark, André, Cécile, National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, Centro Italiano Ricerche Aerospaziali (CIRA ), Agenzia Spaziale Italiana (ASI), German Aerospace Center (DLR), National Technical University of Athens [Athens] (NTUA), DTIS, ONERA [Salon], ONERA, TU-Munich, Delft University of Technology (TU Delft), University of Glasgow, and University of Liverpool more...
- Subjects
[PHYS]Physics [physics] ,[SPI]Engineering Sciences [physics] ,EOLIENNE ,[SPI] Engineering Sciences [physics] ,[INFO]Computer Science [cs] ,DYNAMIQUE VOL ,[MATH] Mathematics [math] ,[MATH]Mathematics [math] ,[INFO] Computer Science [cs] ,HELICOPTERE ,[PHYS] Physics [physics] - Abstract
The effects of a wind turbine wake on General Aviation and the behaviour of helicopters in the tip vortex of large fixed-wing aircraft has been topic of research in the past years, but less is known about the interactions of helicopters operating in a wind turbine wake. A dedicated GARTEUR Action Group, HC-AG23, consisting of European universities and research institutes was formed to investigate helicopter behaviour in a wind tur-bine wake and to study the consequences for helicopter handling and safety of flight. The activities are struc-tured in work packages addressing wind turbine wake identification, wake experiments and computations, offline and piloted simulations and management and dissemination activities. This paper presents an over-view of the partners’ activities and provides a short overview of the results that have been achieved in the past three years., Synthèse des activités du groupe GARTEUR HC-AG23 sur l'étude de la problématique du vol des hélicoptères dans le sillage des éoliennes more...
- Published
- 2018
18. An Analysis of Decentralized Airspace Structure and Capacity Using Fast-Time Simulations
- Author
-
Sunil, Emmanuel, Ellerbroek, Joost, Hoekstra, Jacco, Vidosavljevic, Andrija, Arntzen, Michael, Bussink, Frank, Nieuwenhuisen, Dennis, Delft University of Technology (TU Delft), Ecole Nationale de l'Aviation Civile (ENAC), National Aerospace Laboratory [Amsterdam] (NLR), and National Aerospace more...
- Subjects
ComputerApplications_COMPUTERSINOTHERSYSTEMS ,[SPI.AUTO]Engineering Sciences [physics]/Automatic - Abstract
International audience; The work that is presented in this paper is part of an ongoing study on the relationship between airspace structure and capacity. The present paper investigates the degree of structuring needed to maximize capacity for decentralized en route airspace. To this end, four decentralized en route airspace concepts, which vary in terms of the number of constrained degrees of freedom, were compared using fast-time simulations, for both nominal and non-nominal conditions. The airspace structure–capacity relationship was studied from the effect of multiple traffic demand densities on airspace metrics. The results indicated that structuring methods that overconstrained the horizontal path of aircraft reduced capacity because traffic demand displays no predominant patterns in the horizontal dimension for decentralization. The results also showed that capacity was maximized when a vertical segmentation of airspace was used to separate traffic with different travel directions at different flight levels. This mode of structuring improved performance over completely unstructured airspace by reducing relative velocities between aircraft cruising at the same altitude, while allowing direct horizontal routes. more...
- Published
- 2017
- Full Text
- View/download PDF
19. Benchmark for experimentation of acoustic transmission loss applied to helicopter trim panels
- Author
-
Wijntjes, R., Simon, F., Haase, T., Unruh, O., Tijs, E., National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, ONERA - The French Aerospace Lab [Toulouse], ONERA, German Aerospace Center (DLR), Microflown Technologies, and André, Cécile more...
- Subjects
TL ,Transmission loss ,ACOUSTIQUE ,[INFO.INFO-MO] Computer Science [cs]/Modeling and Simulation ,experiments ,HELICOPTERE ,[INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation ,trim panel ,PANNEAU HABILLAGE ,Adaptronik ,helicopter - Abstract
International audience; The acoustic Transmission Loss (TL) of a vibrating structure, like a sample of helicopter trim panel, is generally measured in a laboratory set-up within controlled conditions. It represents the ratio between the incident acoustic power and the acoustic power radiated by the panel. To estimate its vibro-acoustic behaviour, it is essential to know precisely the nature of incident pressure field and to distinguish the influence of panel size and boundary conditions. Moreover, the relevance of the outputs depends on the experimental surroundings and instrumentation.The aim of this paper is to present an experimental benchmark study involving different laboratories and operating processes (in laboratory or "in situ") of "Helicopter GARTEUR (Group for Aeronautical Research and Technology in Europe) Action Group AG20" and relative to the measurement of TL applied to reference trim panels. more...
- Published
- 2016
20. The Influence of Traffic Structure on Airspace Capacity
- Author
-
Sunil, Emmanuel, Hoekstra, Jacco, Ellerbroek, Joost, Bussink, Frank, Vidosavljevic, Andrija, Delahaye, Daniel, Aalmoes, Roalt, Delft University of Technology (TU Delft), National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, ENAC - Laboratoire de Mathématiques Appliquées, Informatique et Automatique pour l'Aérien (MAIAA), Ecole Nationale de l'Aviation Civile (ENAC), Institut de Mathématiques de Toulouse UMR5219 (IMT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), European Project: 341508,EC:FP7:TPT,FP7-AAT-2012-RTD-L0,METROPOLIS(2013), Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
airspace structure ,airspace capacity ,air transportation system performance ,en-route airspace design ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] ,air traffic control - Abstract
Best paper award for the Network Management track; International audience; Airspace structure can be used as a procedural mechanism for a priori separation and organization of en-route air traffic. Although many studies have explored novel structuring methods to increase en-route airspace capacity, the relationship between the level of structuring of traffic and airspace capacity is not well established. To better understand the influence of traffic structure on airspace capacity, in this research, four airspace concepts, representing discrete points along the dimension of structure, were compared using large-scale simulation experiments. By subjecting the concepts to multiple traffic demand scenarios, the structure-capacity relationship was inferred from the effect of traffic demand variations on safety, efficiency and stability metrics. These simulations were performed within the context of a future personal aerial transportation system, and considered both nominal and non-nominal conditions. Simulation results suggest that the structuring of traffic must take into account the expected traffic demand pattern to be beneficial in terms of capacity. Furthermore, for the heterogeneous, or uniformly distributed, traffic demand patterns considered in this work, a decentralized layered airspace concept, in which each altitude band limited horizontal travel to within a predefined heading range, led to the best balance of all the metrics considered. more...
- Published
- 2016
21. Complexity Analysis of the Concepts of Urban Airspace Design for METROPOLIS Project
- Author
-
Vidosavljevic, Andrija, Delahaye, Daniel, Sunil, Emmanuel, Bussink, Frank, Hoekstra, Jacco, ENAC - Laboratoire de Mathématiques Appliquées, Informatique et Automatique pour l'Aérien (MAIAA), Ecole Nationale de l'Aviation Civile (ENAC), Delft University of Technology (TU Delft), National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, ENRI, European Project: 341508,EC:FP7:TPT,FP7-AAT-2012-RTD-L0,METROPOLIS(2013), Porte, Laurence, and Metropolis, Urban Airspace Design - METROPOLIS - - EC:FP7:TPT2013-10-01 - 2015-04-30 - 341508 - VALID more...
- Subjects
Personal Air Vehicles ,Unmanned Air Vehicle ,[MATH.MATH-OC] Mathematics [math]/Optimization and Control [math.OC] ,[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] ,Traffic complexity ,Metropolis ,Future urban airspace design - Abstract
International audience; The world population is expected to grow further with a major increase in population living in urban areas. Exploiting the door-to-door concept to the full extent, a considerable part of conventional vehicles may be replaced by personal aerial vehicles. Cargo delivery system will the follow same philosophy using unmanned aerial vehicles. This brings up completely new challenges for future air traffic management in urban environments. The Metropolis research project investigates radically new airspace design concepts for the urban environments 50+ years into the future, which are extreme when compared to today in terms of traffic density, complexity and constraints. This work presents the results of simulation data analysis and a comparison of concepts of urban airspace design regarding organizational (complexity) metrics. The aim was to identify how the structure involved in the concept of urban airspace design influences the complexity of the traffic situation. In this work geometrical metrics, which are only linked to trajectory structure and not to the system used to process them, were used to measure complexity. A robust extension of proximity-convergence metrics as a compound metric has been developed for the ultimate concept evaluation. more...
- Published
- 2015
22. Metropolis: Relating Airspace Structure and Capacity for Extreme Traffic Densities
- Author
-
Sunil, E., Hoekstra, J., Joost Ellerbroek, Bussink, F., Nieuwenhuisen, D., Vidosavljevic, A., Kern, S., Delft University of Technology (TU Delft), National Aerospace Laboratory [Amsterdam] (NLR), National Aerospace, ENAC - Laboratoire de Mathématiques Appliquées, Informatique et Automatique pour l'Aérien (MAIAA), Ecole Nationale de l'Aviation Civile (ENAC), German Aerospace Center (DLR), FAA & Eurocontrol, European Project: 341508,EC:FP7:TPT,FP7-AAT-2012-RTD-L0,METROPOLIS(2013), Porte, Laurence, and Metropolis, Urban Airspace Design - METROPOLIS - - EC:FP7:TPT2013-10-01 - 2015-04-30 - 341508 - VALID more...
- Subjects
airspace structure ,urban airspace design ,Personal Aerial Vehicles (PAVs) ,[SPI]Engineering Sciences [physics] ,free flight ,[SPI] Engineering Sciences [physics] ,4D trajectory based operations ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Unmanned Aerial Vehicles (UAVs) ,air traffic control - Abstract
International audience; Personal and unmanned aerial vehicles have received increasing media attention over the last decade. As a result of the growing excitement for these two aircraft types, many within and outside the aerospace industry envision a future in which large numbers of small aircraft fly over urban areas. With this vision for the future, the question arises what would be required, in terms of airspace organization, to make this feasible, or in deed, if it will be possible at all. In this context, the Metropolis project aims to investigate the influence of airspace structure on capacity, complexity, safety, and efficiency for high - density airspace. To this end, four airspace concepts, ranging fro m a decentralized direct routing concept, to a highly structured tube network using 4D trajectory - based operations, have been considered. The four concepts were compared by means of large - scale simulation experiments, for multiple scenarios that are extrem e when compared to current air traffic densities. This paper presents an overview of the Metropolis project with a focus on the project objectives, design and implementation of airspace concepts, and preliminary simulation results. more...
- Published
- 2015
23. Silicon nanowire array architecture for heterojunction electronics
- Author
-
Abashin, S. [National Aerospace University “Kharkiv Aviation Institute”, Department of Physics (Ukraine)]
- Published
- 2017
- Full Text
- View/download PDF
24. BPG-Based Automatic Lossy Compression of Noisy Images with the Prediction of an Optimal Operation Existence and Its Parameters
- Author
-
Bogdan Kovalenko, Vladimir Lukin, Sergii Kryvenko, Victoriya Naumenko, Benoit Vozel, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Higher Education, Research and Innovation (MESRI) [46844Z], and French Ministries of Europe and Foreign Affairs (MEAE) [46844Z] more...
- Subjects
Fluid Flow and Transfer Processes ,noise ,image lossy compression ,optimal operation point ,Process Chemistry and Technology ,General Engineering ,quality prediction ,Computer Science Applications ,[SPI]Engineering Sciences [physics] ,discrete cosine transform ,automation ,General Materials Science ,Instrumentation - Abstract
International audience; With a resolution improvement, the size of modern remote sensing images increases. This makes it desirable to compress them, mostly by using lossy compression techniques. Often the images to be compressed (or some component images of multichannel remote sensing data) are noisy. The lossy compression of such images has several peculiarities dealing with specific noise filtering effects and evaluation of the compression technique's performance. In particular, an optimal operation point (OOP) may exist where quality of a compressed image is closer to the corresponding noise-free (true) image than the uncompressed (original, noisy) image quality, according to certain criterion (metrics). In such a case, it is reasonable to automatically compress an image under interest in the OOP neighborhood, but without having the true image at disposal in practice, it is impossible to accurately determine if the OOP does exist. Here we show that, by a simple and fast preliminary analysis and pre-training, it is possible to predict the OOPs existence and the metric values in it with appropriate accuracy. The study is carried out for a better portable graphics (BPG) coder for additive white Gaussian noise, focusing mainly on one-component (grayscale) images. The results allow for concluding that prediction is possible for an improvement (reduction) in the quality metrics of PSNR and PSNR-HVS-M. In turn, this allows for decision-making about the existence or absence of an OOP. If an OOP is absent, a more "careful" compression is recommended. Having such rules, it then becomes possible to carry out the compression automatically. Additionally, possible modifications for the cases of signal-dependent noise and the joint compression of three-component images are considered and the possible existence of an OOP for these cases is demonstrated. more...
- Published
- 2022
- Full Text
- View/download PDF
25. Lossy Compression of Three-Channel Remote Sensing Images with 'Color' Component Downscaling
- Author
-
Makarichev, Victor, Proskura, Galina, Rubel, Oleksii, Lukin, Vladimir V., Vozel, Benoit, Chehdi, Kacem, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ) more...
- Subjects
remote sensing ,noise ,[SPI]Engineering Sciences [physics] ,lossy compression ,multispectral ,probability of correct classification - Abstract
International audience; Multichannel systems of remote sensing provide a huge amount of data useful for different applications. However, such images occupy a large space that poses problems of processing, storage, transmission, and management. Lossy compression is widely used to decrease the size of data. In lossy compression, one has to provide a reasonable trade-off between compression ratio (CR) and introduced losses or quality of compressed data. Quality can be characterized in various ways including traditional criteria as peak signal-to-noise ratio (PSNR) or some others as well as criteria that describe efficiency of solving the final tasks of remote sensing as, e.g., probability of correct classification. In this paper, we concentrate on classification of three-channel images that can be either color images or three components of multi- or hyperspectral data acquired, e.g., by Sentinel-2 sensor. In lossy compression of color images, downscaling of color components is often applied to increase CR without essential loss of quality. The goal of this paper is to study the influence of such downscaling on classification accuracy for three-channel remote sensing data. The compression method based on atomic functions is considered since this method allows easy control of compressed image quality and its providing. The neural networks trained for distorted-free images are applied for image classification. Analysis is carried out for four images of different complexity. Based on it, practical recommendations are given. more...
- Published
- 2022
- Full Text
- View/download PDF
26. Improvement of Spatial Localization Accuracy in Learning-Based Patch Matching Using Anisotropic Fractal Brownian Motion Data
- Author
-
Uss, Mykhail. M., Vozel, Benoit, Lukin, Vladimir V., Chehdi, Kacem, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, and Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ) more...
- Subjects
similarity measure ,[SPI]Engineering Sciences [physics] ,exhaustive search ,anisotropic fractal Brownian motion ,multimodal images - Abstract
International audience; The exhaustive search of multiple matches in an overlapping area of two multimodal remote sensing images and the accurate localization of found matches are inherent steps to an efficient registration of these two images. A supervised approach based on convolutional neural networks can address this challenge by producing a similarity map, identifying potential matches within a preset search area and estimating a covariation matrix of their location errors. The training is based on a specially designed loss function to enforce the translational and rotational invariance of the similarity map. Using synthetic samples from anisotropic fractal Brownian motion (afBm) models of different orientation, we made the experimental finding that this loss function is biased with respect to orientation. This bias problem is then addressed by beneficially adding pure afBm data to the learning process. more...
- Published
- 2022
- Full Text
- View/download PDF
27. Implementation of Preventive Activity; Foreign Experience in Criminological Work of Forensic Science Institutions
- Author
-
Nataliia Filipenko, Ihor Shynkarenko, Hanna Spitsyna, Vitalii Tsymbalistyi, and National Aerospace University 'KhAI', Ukraine
- Subjects
criminological activity ,Forensic science ,prevention ,Work (electrical) ,forensic science ,ComputingMilieux_COMPUTERSANDSOCIETY ,forensic expert ,ComputingMilieux_LEGALASPECTSOFCOMPUTING ,Engineering ethics ,forensic science institutions ,Sociology ,international standards - Abstract
This article considers the issue of using modern foreign experience of preventive activity in criminological work of forensic science institutions of Ukraine. Peculiarities of main organisational forms of forensic activity have been analysed through special institutions (forensic science institutions) and through specific professionals: forensic experts (for example, practice of witness institution: professionals who took the oath or obtained a license for forensic examination conducting), international standards used in forensic science. The position of necessity of legislative introduction of international standards in conducting forensic examination is revealed and substantiated. more...
- Published
- 2021
- Full Text
- View/download PDF
28. BPG-Based Lossy Compression of Three-Channel Noisy Images with Prediction of Optimal Operation Existence and Its Parameters
- Author
-
Bogdan Kovalenko, Vladimir Lukin, Benoit Vozel, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), French Ministries of Europe and Foreign Affairs (MEAE), and Higher Education, Research and Innovation (MESRI) through the PHC Dnipro 2021 [46844Z] more...
- Subjects
[SPI]Engineering Sciences [physics] ,image lossy compression ,optimal operation point ,better portable graphics ,quality prediction ,additive noise ,General Earth and Planetary Sciences - Abstract
International audience; Nowadays, there is a clear trend toward increasing the number of remote-sensing images acquired and their average size. This leads to the need to compress the images for storage, dissemination, and transfer over communication lines where lossy compression techniques are more popular. The images to be compressed or some of their components are often noisy. They must therefore be compressed taking into account the properties of the noise. Due to the noise filtering effect obtained during lossy compression of noisy images, an optimal operating point (OOP) may exist. The OOP is a parameter that controls the compression for which the quality of the compressed image is closer (closest) to the corresponding noise-free image than the quality of the noisy (original, uncompressed) image according to some quantitative criterion (metric). In practice, it is important to know whether the OOP exists for a given image, because if the OOP exists, it is appropriate to perform the compression in the OOP or at least in its neighborhood. Since the real image is absent in practice, it is impossible to determine a priori whether the OOP exists or not. Here, we focus on three-channel-remote-sensing images and show that it is possible to easily predict the existence of the OOP. Furthermore, it is possible to predict the metric values or their improvements with appropriate accuracy for practical use. The BPG (better portable graphics) encoder is considered a special case of an efficient compression technique. As an initial design step, the case of additive white Gaussian noise with equal variance in the three components is considered. While previous research was mainly focused on predicting the improvement (reduction) of the PSNR and PSNR-HVS-M metrics, here we focus on the modern visual quality metrics, namely PSNR-HA and MDSI. We also discuss what to do if, according to the prediction, an OOP is absent. Examples of lossy compression of noisy three-channel remote sensing images are given. It is also shown that the use of three-dimensional compression provides a compression ratio increase by several times compared with component-wise compression in the OOP. more...
- Published
- 2023
- Full Text
- View/download PDF
29. Microstructure and transformation behavior of Ni{sub 24.7}Ti{sub 50.3}Pd{sub 25} high temperature shape-memory alloy with Sc micro-addition
- Author
-
Bhaumik, S. [Materials Science Division, CSIR-National Aerospace Laboratories, Bangalore 560 017 (India)]
- Published
- 2015
- Full Text
- View/download PDF
30. Development and characterization of Mn{sup 2+}-doped MgO nanoparticles by solution combustion synthesis
- Author
-
Chakradhar, R. [CSIR- National Aerospace Laboratories, Bangalore -560017 (India)]
- Published
- 2015
- Full Text
- View/download PDF
31. Exhaustive Search of Correspondences between Multimodal Remote Sensing Images Using Convolutional Neural Network
- Author
-
Mykhail Uss, Benoit Vozel, Vladimir Lukin, Kacem Chehdi, National Aerospace University, Institut d'Electronique et de Télécommunications de Rennes (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS), and The research performed in this manuscript was partially supported by the French Ministries of Europe and Foreign Affairs (MEAE) and Higher Education, Research and Innovation (MESRI) through the PHC Dnipro 2021 project No. 46844Z. more...
- Subjects
exhaustive search ,Chemical technology ,deep learning ,similarity measure ,multimodal images ,multiple correspondences ,TP1-1185 ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,[SPI]Engineering Sciences [physics] ,Remote Sensing Technology ,Image Processing, Computer-Assisted ,Neural Networks, Computer ,Electrical and Electronic Engineering ,Instrumentation - Abstract
International audience; Finding putative correspondences between a pair of images is an important prerequisite for image registration. In complex cases such as multimodal registration, a true match could be less plausible than a false match within a search zone. Under these conditions, it is important to detect all plausible matches. This could be achieved by an exhaustive search using a handcrafted similarity measure (SM, e.g., mutual information). It is promising to replace handcrafted SMs with deep learning ones that offer better performance. However, the latter are not designed for an exhaustive search of all matches but for finding the most plausible one. In this paper, we propose a deep-learning-based solution for exhaustive multiple match search between two images within a predefined search area. We design a computationally efficient convolutional neural network (CNN) that takes as input a template fragment from one image, a search fragment from another image and produces an SM map covering the entire search area in spatial dimensions. This SM map finds multiple plausible matches, locates each match with subpixel accuracy and provides a covariance matrix of localization errors for each match. The proposed CNN is trained with a specially designed loss function that enforces the translation and rotation invariance of the SM map and enables the detection of matches that have no associated ground truth data (e.g., multiple matches for repetitive textures). We validate the approach on multimodal remote sensing images and show that the proposed "area" SM performs better than "point" SM. more...
- Published
- 2022
- Full Text
- View/download PDF
32. Problems and Opportunities for Improvement of Legal Framework for Provision of Telemedicine Services: Experience of the Republic of Latvia and Ukraine
- Author
-
Artūrs Žukovs, Nataliia Filipenko, Elza Timule, Hanna Spitsyna, Rīga Stradiņš University, Latvia, and Law Department of National Aerospace University 'Kharkiv Aviation Institute', Ukraine
- Subjects
Socrates 2022, 2 (23) ,telemedicine ,law ,patients’ rights ,medical technologies - Abstract
In recent years technological progress has had a huge impact on healthcare sector. New products, services are becoming popular among patients and healthcare providers. Long waiting periods, to see healthcare specialists and COVID-19 pandemics have influenced the situation as well. As a result of the COVID-19 pandemic, there was a need for non-contact healthcare due to prevalence and infectivity of the disease, which has led to active provision of remote healthcare, both for COVID-19 patients and remote consultations. The aim of the article is to analyse the international regulatory framework of telemedicine, problems, and opportunities for Improvement of the Legal Framework for the Provision of Telemedicine Services. The article will analyse both national regulatory framework of Latvia and Ukraine. Keywords: law, medical technologies, patients’ rights, telemedicine more...
- Published
- 2022
33. Discrete Atomic Transform-Based Lossy Compression of Three-Channel Remote Sensing Images with Quality Control
- Author
-
Victor Makarichev, Irina Vasilyeva, Vladimir Lukin, Benoit Vozel, Andrii Shelestov, Nataliia Kussul, National Aerospace University, Institut d'Electronique et de Télécommunications de Rennes (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS), National Technical University of Ukraine 'Kyiv Polytechnic Institute' [Kiev], Space Research Institute of the NASU and NSAU, National Academy of Sciences of Ukraine (NASU)-National Space Agency of Ukraine (NSAU), National Research Foundation of Ukraine [2020/01.0273, 2020.01/0268, 2020.02/0284], French Ministry of Europe and Foreign Affairs (MEAE) [46844Z], and French Ministry of Higher Education, Research and Innovation (MESRI) [46844Z] more...
- Subjects
remote sensing ,[SPI]Engineering Sciences [physics] ,discrete atomic transform ,lossy compression ,Science ,privacy protection ,General Earth and Planetary Sciences ,Data_CODINGANDINFORMATIONTHEORY ,image quality control ,image classification - Abstract
International audience; Lossy compression of remote sensing data has found numerous applications. Several requirements are usually imposed on methods and algorithms to be used. A large compression ratio has to be provided, introduced distortions should not lead to sufficient reduction of classification accuracy, compression has to be realized quickly enough, etc. An additional requirement could be to provide privacy of compressed data. In this paper, we show that these requirements can be easily and effectively realized by compression based on discrete atomic transform (DAT). Three-channel remote sensing (RS) images that are part of multispectral data are used as examples. It is demonstrated that the quality of images compressed by DAT can be varied and controlled by setting maximal absolute deviation. This parameter also strictly relates to more traditional metrics as root mean square error (RMSE) and peak signal-to-noise ratio (PSNR) that can be controlled. It is also shown that there are several variants of DAT having different depths. Their performances are compared from different viewpoints, and the recommendations of transform depth are given. Effects of lossy compression on three-channel image classification using the maximum likelihood (ML) approach are studied. It is shown that the total probability of correct classification remains almost the same for a wide range of distortions introduced by lossy compression, although some variations of correct classification probabilities take place for particular classes depending on peculiarities of feature distributions. Experiments are carried out for multispectral Sentinel images of different complexities. more...
- Published
- 2022
- Full Text
- View/download PDF
34. Spatial Complexity Reduction in Remote Sensing Image Compression by Atomic Functions
- Author
-
Viktor O. Makarichev, Vladimir V. Lukin, Iryna V. Brysina, Benoit Vozel, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), National Research Foundation of Ukraine from the state budget [2020/01.0273, 2020.01/0268, 2020.02/0284], French Ministry of Europe and Foreign Affairs (MEAE) through the PHC Dnipro 2021, and French Ministry Higher Education, Research and Innovation (MESRI) through the PHC Dnipro 2021 [46844Z] more...
- Subjects
Complexity theory ,Image coding ,spatial complexity ,Geotechnical Engineering and Engineering Geology ,Transforms ,lossy image compression ,Discrete cosine transforms ,[SPI]Engineering Sciences [physics] ,discrete atomic transform (DAT) ,discrete atomic compression (DAC) ,Atomic functions ,Transform coding ,Electrical and Electronic Engineering ,Memory management ,Digital images - Abstract
International audience; Remote sensing (RS) digital images have a great variety of applications in solving real-world problems. Modern sensors provide this type of data of a very high resolution, which, in combination with a great number of acquired images, makes a problem of compressing RS images of particular importance. In this letter, discrete atomic compression (DAC) and a problem of its spatial complexity reduction are considered. This approach provides data compression and protection features in combination with such image representation that is ready for applying different artificial intelligence methods. For this reason, its application to image processing is relevant. Several modifications that provide reducing the spatial complexity of DAC are proposed, and their efficiency is analyzed. In particular, it is shown that using a block splitting procedure, it is possible to get a significant decrease in additional memory expenses without DAC's efficiency degradation in terms of lossy image compression. more...
- Published
- 2022
- Full Text
- View/download PDF
35. Development Strategy of International Cooperation of Forensic Science Institutions of Ukraine with Foreign Experts in Prevention of Terrorist Attacks on Critical Infrastructure
- Author
-
Nataliia Filipenko, Hanna Spitsyna, and Law Department of National Aerospace University 'Kharkiv Aviation Institute', Ukraine
- Subjects
Socrates 2022, 2 (23) ,prevention ,critical infrastructure facilities ,forensic science ,forensic expert ,international standards - Abstract
The issue of using modern foreign experience of preventive activity in criminological work of forensic science institutions of Ukraine has been considered in this study. Peculiarities of the main organisational forms of forensic science activity have been analysed through specialised (forensic science) institutions and through specific specialists, namely: forensic experts (for example, practice of the institute of sworn experts: specialists who took the oath or received a license for forensic examination). Analysis of international standards used in forensic science activity has been carried out. Necessity position of legislative introduction of international standards in process of forensic examination has been revealed and substantiated. The main emphasis is on highlighting problems of cooperation of forensic institutions of Ukraine with foreign experts in preventing terrorist attacks on critical infrastructure. The research aim is to study the use of modern foreign experience in preventive activities in criminological work of forensic expert institutions of Ukraine. The result of the study provides evaluation of the problems of cooperation of forensic institutions of Ukraine with foreign experts in preventing terrorist attacks on critical infrastructure. Based on this evaluation, a proposal is put forward for the improvement of normative regulations. Keywords: forensic science, forensic expert, international standards, prevention, critical infrastructure facilities more...
- Published
- 2022
36. Discrete atomic compression of satellite images: a comprehensive efficiency research
- Author
-
Viktor Makarichev, Benoit Vozel, Vladimir V. Lukin, Kacem Chehdi, Iryna Victorivna Brysina, National Aerospace University, Institut d'Electronique et de Télécommunications de Rennes (IETR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Supérieure d'Electricité - SUPELEC (FRANCE)-Centre National de la Recherche Scientifique (CNRS), French Ministry of Europe and Foreign Affairs (MEAE) [46844Z], French Ministry of Higher Education, Research and Innovation (MESRI) [46844Z], [2020.01/0268], Bruzzone, Bovolo, Benediktsson, and JA more...
- Subjects
Lossless compression ,atomic wavelet ,discrete atomic transform ,Computer science ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Binary number ,Data_CODINGANDINFORMATIONTHEORY ,Huffman coding ,image compression ,Digital image ,symbols.namesake ,[SPI]Engineering Sciences [physics] ,Wavelet ,atomic function ,lossy compression ,Encoding (memory) ,Compression (functional analysis) ,Computer Science::Multimedia ,symbols ,Algorithm ,Test data - Abstract
International audience; In this paper, a problem of resource expenses needed for storage, processing and transferring a large number of high resolution digital remote sensing images is considered. Application of discrete atomic compression (DAC), which is an algorithm based on atomic wavelets, to solving this problem is studied. Dependence of efficiency of the DAC algorithm on its parameters, in particular, quality loss settings, a structure of discrete atomic transform, which is a core of DAC, and a method of quantized wavelet coefficients' encoding, is investigated. Binary arithmetic coding and a combination of Huffman codes with run-length encoding are used to provide lossless compression of quantized atomic wavelet coefficients. Comparison of these methods is presented. A set of digital images of the European Space Agency is employed as test data. In addition, we discuss promising ways to improve the DAC algorithm. more...
- Published
- 2021
- Full Text
- View/download PDF
37. Editorial to special issue 'remote sensing data compression'
- Author
-
Joan Serra-Sagrista, Benoit Vozel, Vladimir V. Lukin, Institut d'Électronique et des Technologies du numéRique (IETR), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), National Aerospace University, Universitat Autònoma de Barcelona (UAB), Generalitat de Catalunya: 2017SGR-463, Ministerio de Economía y Competitividad, MINECO, European Regional Development Fund, ERDF: RTI2018-095287-B-I00, Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and Université de Nantes (UN)-Université de Rennes 1 (UR1) more...
- Subjects
010504 meteorology & atmospheric sciences ,Computer science ,Remote sensing data compression ,Science ,0211 other engineering and technologies ,Image processing ,02 engineering and technology ,Data_CODINGANDINFORMATIONTHEORY ,Lossy compression ,01 natural sciences ,[SPI]Engineering Sciences [physics] ,Software ,Compression (functional analysis) ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Lossless compression ,Artificial neural network ,business.industry ,Computational complexity ,Compression impact ,General Earth and Planetary Sciences ,business ,Neural networks ,Data compression ,Coding (social sciences) - Abstract
International audience; A huge amount of remote sensing data is acquired each day, which is transferred to image processing centers and/or to customers. Due to different limitations, compression has to be applied on-board and/or on-the-ground. This Special Issue collects 15 papers dealing with remote sensing data compression, introducing solutions for both lossless and lossy compression, analyzing the impact of compression on different processes, investigating the suitability of neural networks for compression, and researching on low complexity hardware and software approaches to deliver competitive coding performance. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. more...
- Published
- 2021
- Full Text
- View/download PDF
38. Lossy compression of multichannel remote sensing images with quality control
- Author
-
Fangfang Li, Benoit Vozel, Kacem Chehdi, Vladimir V. Lukin, Sergey Krivenko, Oleksii Rubel, Sergey K. Abramov, Irina Vasilyeva, Karen Egiazarian, Tampere University, Computing Sciences, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Tampere University of Technology [Tampere] (TUT), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and Université de Nantes (UN)-Université de Rennes 1 (UR1) more...
- Subjects
Computer science ,Image quality ,Image classification ,Science ,0211 other engineering and technologies ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,Data_CODINGANDINFORMATIONTHEORY ,Lossy compression ,[SPI]Engineering Sciences [physics] ,Distortion ,0202 electrical engineering, electronic engineering, information engineering ,Visibility ,021101 geological & geomatics engineering ,Remote sensing ,Pixel ,Artificial neural network ,Contextual image classification ,213 Electronic, automation and communications engineering, electronics ,remote sensing ,lossy compression ,image quality ,image classification ,visual quality metrics ,Compression ratio ,General Earth and Planetary Sciences ,020201 artificial intelligence & image processing ,Visual quality metrics - Abstract
International audience; Lossy compression is widely used to decrease the size of multichannel remote sensing data. Alongside this positive effect, lossy compression may lead to a negative outcome as making worse image classification. Thus, if possible, lossy compression should be carried out carefully, controlling the quality of compressed images. In this paper, a dependence between classification accuracy of maximum likelihood and neural network classifiers applied to three-channel test and real-life images and quality of compressed images characterized by standard and visual quality metrics is studied. The following is demonstrated. First, a classification accuracy starts to decrease faster when image quality due to compression ratio increasing reaches a distortion visibility threshold. Second, the classes with a wider distribution of features start to “take pixels” from classes with narrower distributions of features. Third, a classification accuracy might depend essentially on the training methodology, i.e., whether features are determined from original data or compressed images. Finally, the drawbacks of pixel-wise classification are shown and some recommendations on how to improve classification accuracy are given. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. more...
- Published
- 2020
- Full Text
- View/download PDF
39. Automation of Processing Multichannel Remote Sensing Images Based on Performance Prediction
- Author
-
Vladimir V. Lukin, Oleksii Rubel, Nataliia Kussul, Karen Egiazarian, Benoit Vozel, Mikhail L. Uss, Sergey K. Abramov, National Aerospace University, Space Research Institute of the NASU and NSAU, National Academy of Sciences of Ukraine (NASU)-National Space Agency of Ukraine (NSAU), Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Tampere University of Technology [Tampere] (TUT), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
Data processing ,Computer science ,business.industry ,Carry (arithmetic) ,0211 other engineering and technologies ,02 engineering and technology ,performance prediction ,Automation ,Set (abstract data type) ,remote sensing ,[SPI]Engineering Sciences [physics] ,Remote sensing (archaeology) ,0202 electrical engineering, electronic engineering, information engineering ,Performance prediction ,020201 artificial intelligence & image processing ,Stage (hydrology) ,business ,multichannel images ,automation ,021101 geological & geomatics engineering ,Remote sensing - Abstract
International audience; This paper deals with processing of multichannel remote sensing images for which it is difficult and often impossible to carry out any stage of data processing in an interactive manner and, thus, full or, at least, partial automation is needed. Despite of existence of many methods, it is difficult to choose the best or an appropriate one and/or to set its parameters. One reason is that quantitative criteria characterizing efficiency of applicable methods are often unknown, especially for remote sensing data at hand. Thus, it is desirable to have some preliminary prediction of errors or accuracy for data processing methods and to choose a good method and its parameters properly. Here we consider few approaches and describe the results already obtained in recent years. © 2020 IEEE. more...
- Published
- 2020
- Full Text
- View/download PDF
40. Comparison of learning-based and maximum-likelihood estimators of image noise variance for real-life and synthetic anisotropic textures
- Author
-
Kacem Chehdi, Vladimir V. Lukin, Benoit Vozel, Mykhail Uss, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Bruzzone L.Bovolo F.Santi E., Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and Nantes Université (NU)-Université de Rennes 1 (UR1) more...
- Subjects
Computer science ,0211 other engineering and technologies ,Convolutional neural network ,Experimental data ,02 engineering and technology ,Synthetic data ,Standard deviation ,[SPI]Engineering Sciences [physics] ,Hard mining ,Signal-to-noise ratio ,Multivariate noise variance model ,Blind noise parameter estimation ,0202 electrical engineering, electronic engineering, information engineering ,Image noise ,021101 geological & geomatics engineering ,Signal-dependency ,business.industry ,Anisotropic fractional Brownian motion ,Estimator ,Pattern recognition ,Real image ,Noise ,020201 artificial intelligence & image processing ,Artificial intelligence ,Deep regression with uncertainty ,business - Abstract
International audience; Processing of remote sensing data is often based on an assumption that noise parameters in component images are a priori known. If this assumption is not valid, it is desired to perform estimation of noise parameters directly from noisy image patches. In this paper, two estimators - model- and learning-based ones possessing the ability to evaluate noise standard deviation (SD) or variance and to predict estimation accuracy for each image patch are considered. The former approach is the representative of maximum likelihood estimator (MLE) of parameters for anisotropic fractional Brownian motion (afBm) field whilst the learning-based one is the representative of convolutional neural networks (CNN) that employs training on real-life images. Our goal is to compare the performance for two cases: for pure afBm data and for real-life images. It is shown that the learning-based approach occurs to be less effective for pure afBm data since it produces a certain bias whilst the model-based approach runs into problems for complex image patches in reallife images. Based on this analysis, we propose to use synthetic afBm data as additional source of training data for learning-based methods of noise parameters estimation. By mixing real and synthetic data for training of the NoiseNet CNN, we were able to improve its performance in both domains. For afBm data, NoiseNet bias was significantly reduced and ability to predict noise SD estimates confidence improved. On NED2012 database of real images, the modified NoiseNet reduces signal-independent noise SD component estimation error by about 40% as compared to the original CNN version. © SPIE. Downloading of the abstract is permitted for personal use only. more...
- Published
- 2020
- Full Text
- View/download PDF
41. Atomic wavelets in lossy and near-lossless image compression
- Author
-
Iryna Victorivna Brysina, Victor Olexandrovych Makarichev, Kacem Chehdi, Benoit Vozel, Vladimir V. Lukin, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Bruzzone L.Bovolo F.Santi E., Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and Nantes Université (NU)-Université de Rennes 1 (UR1) more...
- Subjects
Differential equations ,Atoms ,Near lossless compression ,Image compression ,Compactly-supported solutions ,Computer science ,Functional differential equations ,Data_CODINGANDINFORMATIONTHEORY ,Lossy compression ,01 natural sciences ,[SPI]Engineering Sciences [physics] ,Digital image ,Wavelet ,Satellite remote sensing ,Compression (functional analysis) ,0103 physical sciences ,0101 mathematics ,Near-lossless image compressions ,010303 astronomy & astrophysics ,Lossless compression ,Signal to noise ratio ,Privacy by design ,010102 general mathematics ,Peak signal to noise ratio ,computer.file_format ,Remote sensing ,JPEG ,Compression techniques ,Compression ratio ,Algorithm ,computer ,Maximum absolute deviations - Abstract
International audience; One of distinguishing features of the present is the explosive increase in data amount including digital images such as satellite remote sensing images. Processing, storing and transmission via networks of a huge number of digital images requires considerable resources in the sense of memory, time, computational power, etc. In this regard, the importance of image compression is growing and the development of novel compression techniques that would satisfy new requirements, for instance, to security and level of privacy protection continues. Atomic wavelets and their generalizations can be a useful tool for this. They are constructed using atomic functions, which are compactly supported solutions of special functional differential equations. Discrete atomic transform (DAT), which is a process of computation of expansion coefficients of the function describing the source discrete data, is applied in discrete atomic compression (DAC). DAC can be applied to compression of full color digital images, as well as monocomponent ones. In this paper, we investigate efficiency, which is measured by compression ratio (CR), of satellite image compression using DAC and the corresponding loss of quality measured by several quantitative criteria. They are maximum absolute deviation (MAD), root mean square (RMS) and peak signal-to-noise ratio (PSNR). We show that DAC provides near lossless compression, when quality loss is minor in a sense of the MAD-metric. Also, it is proved that using DAC it is possible to obtain better compression than by applying JPEG with the same quality of the obtained results. © SPIE. Downloading of the abstract is permitted for personal use only. more...
- Published
- 2020
- Full Text
- View/download PDF
42. Prediction of Visual Quality Metrics in Lossy Image Compression
- Author
-
Fangfang Li, Vladimir V. Lukin, Benoit Vozel, O. Krylova, Sergey Krivenko, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
Computer science ,media_common.quotation_subject ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Data_CODINGANDINFORMATIONTHEORY ,02 engineering and technology ,Lossy compression ,030218 nuclear medicine & medical imaging ,Image (mathematics) ,03 medical and health sciences ,0302 clinical medicine ,lossy compression ,0202 electrical engineering, electronic engineering, information engineering ,Discrete cosine transform ,[CHIM]Chemical Sciences ,Quality (business) ,Computer vision ,image ,Image resolution ,media_common ,Pixel ,business.industry ,metric prediction ,visual quality ,Compression ratio ,Metric (mathematics) ,020201 artificial intelligence & image processing ,Artificial intelligence ,business - Abstract
International audience; Images of different origin are widely used nowadays in various applications including medical diagnostic systems, remote sensing, etc. Due to modern tendency to improve imaging system resolution and increase image size, it has often become necessary to compress images before their storage and transferring via communication lines. Lossy compression is mostly employed for this purpose and an important task for it is to find and provide an appropriate compromise between compression ratio and quality of compressed data, in the first order, image visual quality. This paper considers an approach to predicting visual quality characterized by the metrics MSEHVSM or, equivalently, PSNR-HVS-M for the coder AGU based on discrete cosine transform (DCT). It is demonstrated that it is possible to estimate MSEHVSM in a limited number of 8×8 pixel blocks and then to predict this metric for the entire image for the considered coder. The influence of image content and the number of analyzed blocks is studied. It is shown that 500 or 1000 blocks are usually enough to carry out prediction with appropriate accuracy. © 2020 IEEE. more...
- Published
- 2020
- Full Text
- View/download PDF
43. Peculiarities of hyperspectral image lossy compression for sub-band groups
- Author
-
Oleg Ieremeiev, Benoit Vozel, Vladimir V. Lukin, Alexander N. Zemliachenko, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Antyufeyeva M., Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
Mean squared error ,Computer science ,0211 other engineering and technologies ,Hyperspectral imaging ,02 engineering and technology ,Data_CODINGANDINFORMATIONTHEORY ,Comparison ,Lossy compression ,Image (mathematics) ,[SPI]Engineering Sciences [physics] ,Distortion ,Compression (functional analysis) ,Image grouping ,Compression ratio ,0202 electrical engineering, electronic engineering, information engineering ,Discrete cosine transform ,020201 artificial intelligence & image processing ,Algorithm ,021101 geological & geomatics engineering ,3D ,Metric analysis - Abstract
International audience; This paper deals with analysis of component-wise and three-dimensional (3D) lossy compression of hyperspectral data. The latter approach is known to be more efficient due to possibility to employ inter-band correlation of images in neighbor sub-bands. However, there are certain peculiarities for this approach which are subject of our study. Methods of lossy compression that employ discrete cosine transform (DCT) in blocks are studied. It is shown that 3D compression is able to provide considerable benefits in compression ratio and/or mean square error (MSE) of introduced distortions but only under certain conditions. Experiments have been done for real-life hyperspectral data with high input signal-to-noise ratio. Their main results are presented. © 2019 IEEE. more...
- Published
- 2019
- Full Text
- View/download PDF
44. Noninvasive fetal electrocardiography for the detection of fetal arrhythmias
- Author
-
Vyacheslav Shulgin, Oleksii Ostras, Laurent Bonnemains, Julien Oster, Igor Lakhno, Joachim Behar, Technion - Israel Institute of Technology [Haifa], Imagerie Adaptative Diagnostique et Interventionnelle (IADI), Université de Lorraine (UL)-Institut National de la Santé et de la Recherche Médicale (INSERM), National Aerospace University, and Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL) more...
- Subjects
0301 basic medicine ,medicine.medical_specialty ,[SDV.IB.MN]Life Sciences [q-bio]/Bioengineering/Nuclear medicine ,030105 genetics & heredity ,Electrocardiography ,03 medical and health sciences ,Fetal Heart ,0302 clinical medicine ,Pregnancy ,Internal medicine ,medicine ,[INFO.INFO-IM]Computer Science [cs]/Medical Imaging ,Humans ,cardiovascular diseases ,Genetics (clinical) ,Atrial tachycardia ,ComputingMilieux_MISCELLANEOUS ,Fetus ,030219 obstetrics & reproductive medicine ,medicine.diagnostic_test ,business.industry ,Obstetrics and Gynecology ,Arrhythmias, Cardiac ,medicine.disease ,3. Good health ,Fetal ecg ,Fetal Diseases ,Multicenter study ,cardiovascular system ,Cardiology ,Female ,Fetal diagnosis ,medicine.symptom ,business ,Fetal echocardiography ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology - Abstract
Objective To assess whether noninvasive fetal electrocardiography (NI-FECG) enables the diagnosis of fetal arrhythmias. Methods A total of 500 echocardiography and NI-FECG recordings were collected from pregnant women during a routine medical visit in this multicenter study. All the cases with fetal arrhythmias (n = 12) and a matching number of control (n = 14) were used. Two perinatal cardiologists analyzed the extracted NI-FECG while blinded to the echocardiography. The NI-FECG-based diagnosis was compared with the reference fetal echocardiography diagnosis. Results NI-FECG and fetal echocardiography agreed on all cases (Ac = 100%) on the presence of an arrhythmia or not. However, in one case, the type of arrhythmia identified by the NI-FECG was incorrect because of the low resolution of the extracted fetal P-wave, which prevented resolving the mechanism (2:1 atrioventricular conduction) of the atrial tachycardia. Conclusion It is possible to diagnose fetal arrhythmias using the NI-FECG technique. However, this study identifies that improvement in algorithms for reconstructing the P-wave is critical to systematically resolve the mechanisms underlying the arrhythmias. The elaboration of a NI-FECG Holter device will offer new opportunities for fetal diagnosis and remote monitoring of problematic pregnancies because of its low-cost, noninvasiveness, portability, and minimal setup requirements. more...
- Published
- 2019
- Full Text
- View/download PDF
45. Editorial to special issue 'multispectral image acquisition, processing, and analysis'
- Author
-
Yakoub Bazi, Vladimir V. Lukin, Benoit Vozel, Institut d'Électronique et des Technologies du numéRique (IETR), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), National Aerospace University, King Saud University [Riyadh] (KSU), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), and Université de Nantes (UN)-Université de Rennes 1 (UR1) more...
- Subjects
010504 meteorology & atmospheric sciences ,business.industry ,Computer science ,Multispectral image ,0211 other engineering and technologies ,02 engineering and technology ,01 natural sciences ,[SPI]Engineering Sciences [physics] ,n/a ,General Earth and Planetary Sciences ,Computer vision ,lcsh:Q ,Artificial intelligence ,business ,lcsh:Science ,ComputingMilieux_MISCELLANEOUS ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
This Special Issue was announced in March 2018 [...]
- Published
- 2019
- Full Text
- View/download PDF
46. MSE and PSNR prediction for ADCT coder applied to lossy image compression
- Author
-
Sergey Krivenko, Benoit Vozel, Vladimir V. Lukin, Mikhail Zriakhov, Kharkov National University, National Aerospace University, Institut d'Électronique et des Technologies du numéRique (IETR), Nantes Université (NU)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS), Université de Nantes (UN)-Université de Rennes 1 (UR1), Université de Nantes (UN)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-CentraleSupélec-Centre National de la Recherche Scientifique (CNRS) more...
- Subjects
Mean squared error ,Noise measurement ,Computer science ,Image quality ,grayscale images ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,DCT ,020206 networking & telecommunications ,02 engineering and technology ,Data_CODINGANDINFORMATIONTHEORY ,Lossy compression ,Noise ,[SPI]Engineering Sciences [physics] ,Compression ratio ,0202 electrical engineering, electronic engineering, information engineering ,Discrete cosine transform ,020201 artificial intelligence & image processing ,MSE and PSNR prediction ,Algorithm ,Transform coding - Abstract
International audience; Lossy compression of images is used for numerous applications nowadays. Typical requirements to it are to provide a higher compression ratio (CR) for a desired quality and to perform this quickly enough. Advanced discrete cosine transform (ADCT) based coder potentially provides a good compromise between CR and image quality but consumes essential resources for reaching a desired quality of compressed data. To get around this shortcoming, we develop a fast and rather accurate approach to prediction of mean square error (MSE) or peak signal-to-noise ratio (PSNR). This approach performs sufficiently faster than compression and allows saving time and resources. It is shown that if an image to be compressed is corrupted by noise, prediction correction is possible and desirable. © 2018 IEEE. more...
- Published
- 2018
- Full Text
- View/download PDF
47. Analysis of shock unsteadiness in a supersonic over-expanded planar nozzle
- Author
-
Shashi B. Verma, Abdellah Hadjadj, Manisankar Chidambaranathan, CSIR-National Aerospace Laboratories - NAL (INDIA), Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU) more...
- Subjects
020301 aerospace & aeronautics ,Materials science ,Shock (fluid dynamics) ,Turbulence ,Nozzle ,General Physics and Astronomy ,Resonance ,Laminar flow ,02 engineering and technology ,Mechanics ,01 natural sciences ,010305 fluids & plasmas ,[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] ,Physics::Fluid Dynamics ,symbols.namesake ,Boundary layer ,0203 mechanical engineering ,Mach number ,0103 physical sciences ,symbols ,Supersonic speed ,Mathematical Physics ,ComputingMilieux_MISCELLANEOUS - Abstract
An experimental investigation has been conducted to study the unsteady nature of the shock structure in an over-expanded planar nozzle. The main emphasis was to investigate (i) the effect of resonance associated with laminar shock-wave/boundary-layer interactions on the unsteady characteristics of the wall pressure signals in the region of the interaction and, (ii) the change in these characteristics as the state of boundary layer undergoes transition to turbulence and a resonance free interaction. The tests were conducted in a Mach 2 planar nozzle with wall-half angle of 5 . 7 ∘ . For almost all the NPR for which the nozzle is tested, the boundary layer state is seen to be in the laminar/transitional range and exhibits resonance for nozzle pressure ratios less than 2.3. The resonance tones associated with the laminar interactions result in a considerable increase in the length of the intermittent region. However, as the boundary layer state goes into the transitional regime and the resonance tones disappear, the length of intermittent region is seen to decrease significantly. A decrease in this length also causes the peak standard deviation values to decrease. Further a free interaction region is observed for separated nozzle flows irrespective of the NPR of operation for resonance free interactions. more...
- Published
- 2018
- Full Text
- View/download PDF
48. On Intelligent Multiagent Approach to Viral Hepatitis B Epidemic Processes Simulation
- Author
-
Dmytro Chumachenko and National Aerospace University 'Kharkiv Aviation Institute'
- Subjects
business.industry ,incidence prediction ,epidemic process ,multiagent simulation ,Viral hepatitis b ,medicine.disease ,ComputingMethodologies_ARTIFICIALINTELLIGENCE ,Task (project management) ,viral Hepatitis B ,Multi agent model ,medicine ,Artificial intelligence ,Viral hepatitis ,business - Abstract
Simulation of epidemic processes is actual task, which has high social and economic value. Given research is dedicated to the application of the intellectual multiagent approach to the prediction of the incidence of viral hepatitis B. The structure of the model, agents, environment and rules of agents' interaction has been developed. The multi agent model shows high accuracy. more...
- Published
- 2018
49. New national and regional bryophyte records, 52
- Author
-
Ellis, L. T., Alatas, M., Aleffi, M., Alegro, A., Segota, V., Ozimec, S., Vukovic, N., Koletic, N., Prlic, D., Bontek, M., Asthana, A. K., Gupta, D., Sahu, V., Rawat, K. K., Bakalin, V. A., Klimova, K. G., Barath, K., Beldiman, L. N., Csiky, J., Deme, J., Kovacs, D., Cano, M. J., Guerra, J., Czernyadjeva, I. V., Dulin, M. V., Erzberger, P., Ezer, T., Fedosov, V. E., Fontinha, S., Sim-Sim, M., Garcia, C. A., Martins, A., Granzow-de la Cerda, I., Saez, L., Hassel, K., Weibull, H., Hodgetts, N. G., Infante, M., Heras, P., Kiebacher, T., Kucera, J., Lebouvier, M., Ochyra, R., Oeren, M., Papp, B., Park, S. J., Sun, B. -Y., Plasek, V., Poponessi, S., Venanzoni, R., Purger, D., Reis, F., Sinigla, M., Stebel, A., Stefanut, S., Uyar, G., Voncina, G., Wigginton, M. J., Yong, K. -T., Chan, M. S., Yoon, Y. -J., The Natural History Museum [London] (NHM), Università degli Studi di Camerino (UNICAM), University of Zagreb, CSIR-National Aerospace Laboratories - NAL (INDIA), CSIR-National Botanical Research Institute, University of West-Hungary, University of Pecs, Universidad de Murcia, Russian Academy of Sciences [Moscow] (RAS), Freie Universität Berlin, Lomonosov Moscow State University (MSU), Museo de Ciencias Naturales de Alava, University of South Bohemia, Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), W. Szafer Institute of Botany, Polish Academy of Sciences, Zonguldak Bülent Ecevit University (BEU), Chonbuk National University, Technical University of Ostrava [Ostrava] (VSB), Università degli Studi di Perugia (UNIPG), University of Madeira [Funchal], Gazi University, University of Malaya, Natural History Museum, London, Council of Scientific and Industrial Research, New Delhi [BSC-0106], [AAAA-A16-116021010241-9], SAC, ISRO, Ahmadabad, India [3329], Norwegian Biodiversity Information Centre [61-10: 70184219], 'Kornyezetiparhoz kapcsolodo innovativ transz- es interdiszciplinaris kutatoi team fejlesztese a PTE tudomanyos bazisan' (Hungary), Public Institution Nature Park Papuk (Croatia) [TAMOP 4.2.2.D-15/1/KONV-2015-0015], New National Excellence Program of the Ministry of Human Capacities (Hungary) [UNKP-16-2], Russian Foundation for the Basic Researches [15-34-20101], Russian Foundation for Basic Research [15-04-03479-a, 16-44-110167], Russian Science Foundation (RNF) [14-50-00029], Spanish government (FEDER) [CGL2015-64068-P], statutory fund of the W. Szafer Institute of Botany, Polish Academy of Sciences, Institute of Environmental Technologies [CZ.1.05/2.1.00/03.0100], National Feasibility Programme I of the Czech Republic [LO1208], SYNTHESYS project [DE-TAF-4436], Komarov Botanical Institute of the Russian Academy of Sciences [01201255616], RFBR [16-04-01156], Turkish Scientific and Technical Research Council (TUBITAK) [114Z337], Institute of Biology Bucharest of Romanian Academy [RO1567-IBB03/2017], Università degli Studi di Camerino = University of Camerino (UNICAM), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Perugia = University of Perugia (UNIPG), and University of Malaya = Universiti Malaya [Kuala Lumpur, Malaisie] (UM) more...
- Subjects
0106 biological sciences ,0301 basic medicine ,Mediterranean climate ,Ecology ,Biodiversity ,Ricciocarpos natans ,Buxbaumia aphylla ,Plant Science ,030108 mycology & parasitology ,01 natural sciences ,03 medical and health sciences ,Geography ,Component (UML) ,medicine ,medicine.symptom ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Vegetation (pathology) ,Ecology, Evolution, Behavior and Systematics ,ComputingMilieux_MISCELLANEOUS ,010606 plant biology & botany - Abstract
Circumpolar boreal-montane moss Buxbaumia aphylla is a new species for Croatia. We have found 58 capsules and 12 setae at the three sites: the smallest population (10 specimens) was located at Sokolina ; at the two other sites B. aphylla was more abundant (Svinjarevac: 29 specimens, Konjska smrt: 31 specimens). Ricciocarpos natans is reported from several localities. It was discovered during extensive surveys of the macrophytic vegetation throughout Croatia. Based on our recent findings, the species occurs in northern and eastern Croatia, mostly in backwaters, or areas subject to inundation, of the large rivers Danube, Drava and Mura. According to our observations, the species in Croatia occupies relatively small and rather shallow eutrophic stagnant waters. more...
- Published
- 2017
- Full Text
- View/download PDF
50. Forecasting of Patients Condition in the Monitoring Medical Systems on the Example of Prostate Diseases
- Author
-
Goriacha, Veronica A., Sokolov, Oleksandr Yu., Ugryumova, Kateryna M., Antonyan, Igor M., Roshin, Yuri V., Zelensky, Alexandr I., Moshel, Fedor G., Nalbandian, Taron A., Information technology department, National Aerospace University named by N. Ye. Zhukovsky 'Kharkov Aviation Institu te', Ukraine, Department of Informatics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudzianska 5, 87 - 100, Torun, Poland, and Department of General and children's oncological urology, Medical Academy of Postgraduate Educatio n Moscow Avenue 195, 61037, Kharkiv, Ukraine more...
- Subjects
lcsh:Sports ,lcsh:GV557-1198.995 ,computational methods ,Reasoning Methods ,lcsh:R ,lcsh:Medicine ,clinical medicine ,Decision Support Software System ,lcsh:L ,decision support software system, reasoning methods, computational methods, clinical medicine ,lcsh:Education - Abstract
Goriacha Veronica A., Sokolov Oleksandr Yu., Ugryumova Kateryna M., Antonyan Igor M., Roshin Yuri V., Zelensky Alexandr I., Moshel Fedor G., Nalbandian Taron A. Forecasting of Patients Condition in the Monitoring Medical Systems on the Example of Prostate Diseases. Journal of Education, Health and Sport. 2016;6(5):77-93. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.51160 http://ojs.ukw.edu.pl/index.php/johs/article/view/3511 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 755 (23.12.2015). 755 Journal of Education, Health and Sport eISSN 2391-8306 7 © The Author (s) 2016; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 05.04.2016. Revised 25.04.2016. Accepted: 05.05.2016. Forecasting of Patients Condition in the Monitoring Medical Systems on the Example of Prostate Diseases Goriacha Veronica A.1, Sokolov Oleksandr Yu.2, Ugryumova Kateryna M.1, Antonyan Igor M.3, Roshin Yuri V.3, Zelensky Alexandr I.3, Moshel Fedor G.3, Nalbandian Taron A.3 1Information technology department, National Aerospace University named by N. Ye. Zhukovsky “Kharkov Aviation Institute”, Ukraine 2Department of Informatics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudzianska 5, 87-100, Torun, Poland 3Department of General and children's oncological urology, Medical Academy of Postgraduate Education Moscow Avenue 195, 61037, Kharkiv, Ukraine splaijna@gmail.com, osokolov@is.umk.pl, ukatya80@mail.ru, urology.edu.ua@gmail.com Abstract. The mathematical models and computational methods with implementing them applied information technology of decision support in monitoring medical system are proposed. The method of construction robust monitoring indices based diagnostic models for criteria quality assessment of the systems elements condition is described. The informativeness (significance) assessment method of the systems diagnosing models variables, obtained based on artificial neural networks (ANN) theory instrument is developed. The forecasting method of multivariate time series obtained on the monitoring indices based variables of the dynamic systems condition is developed. The method for solving the condition classification problem of the complex systems elements is improved. The decision support computer system in medical monitoring systems is developed. Application examples of the described methods on diagnosis of medical patients are presented. Keywords: Decision Support Software System, Reasoning Methods, computational methods, clinical medicine. Goriacha Veronica A., Sokolov Oleksandr Yu., Ugryumova Kateryna M., Antonyan Igor M., Roshin Yuri V., Zelensky Alexandr I., Moshel Fedor G., Nalbandian Taron A. Forecasting of Patients Condition in the Monitoring Medical Systems on the Example of Prostate Diseases. Journal of Education, Health and Sport. 2016;6(5):77-93. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.51160 http://ojs.ukw.edu.pl/index.php/johs/article/view/3511 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 755 (23.12.2015). 755 Journal of Education, Health and Sport eISSN 2391-8306 7 © The Author (s) 2016; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. This is an open access article licensed under the terms of the Creative Commons Attribution Non Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 05.04.2016. Revised 25.04.2016. Accepted: 05.05.2016. Forecasting of Patients Condition in the Monitoring Medical Systems on the Example of Prostate Diseases Goriacha Veronica A.1, Sokolov Oleksandr Yu.2, Ugryumova Kateryna M.1, Antonyan Igor M.3, Roshin Yuri V.3, Zelensky Alexandr I.3, Moshel Fedor G.3, Nalbandian Taron A.3 1Information technology department, National Aerospace University named by N. Ye. Zhukovsky “Kharkov Aviation Institute”, Ukraine 2Department of Informatics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudzianska 5, 87-100, Torun, Poland 3Department of General and children's oncological urology, Medical Academy of Postgraduate Education Moscow Avenue 195, 61037, Kharkiv, Ukraine splaijna@gmail.com, osokolov@is.umk.pl, ukatya80@mail.ru, urology.edu.ua@gmail.com Abstract. The mathematical models and computational methods with implementing them applied information technology of decision support in monitoring medical system are proposed. The method of construction robust monitoring indices based diagnostic models for criteria quality assessment of the systems elements condition is described. The informativeness (significance) assessment method of the systems diagnosing models variables, obtained based on artificial neural networks (ANN) theory instrument is developed. The forecasting method of multivariate time series obtained on the monitoring indices based variables of the dynamic systems condition is developed. The method for solving the condition classification problem of the complex systems elements is improved. The decision support computer system in medical monitoring systems is developed. Application examples of the described methods on diagnosis of medical patients are presented. Keywords: Decision Support Software System, Reasoning Methods, computational methods, clinical medicine. Walery Zukow more...
- Published
- 2016
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.