Search results for "electrical"

showing 10 items of 11048 documents

A Geometrical Three-Ring-Based Model for MIMO Mobile-to-Mobile Fading Channels in Cooperative Networks

2011

Published version of an article published in the journal: Eurasip Journal on Advances in Signal Processing. Also available from the publisher at: http://dx.doi.org/10.1155/2011/892871. OA This paper deals with the modeling and analysis of narrowband multiple-input multiple-output (MIMO) mobile-to-mobile (M2M) fading channels in relay-based cooperative networks. In the transmission links from the source mobile station to the destination mobile station via the mobile relay, non-line-of-sight (NLOS) propagation conditions are taken into account. A stochastic narrowband MIMO M2M reference channel model is derived from the geometrical three-ring scattering model, where it is assumed that an infi…

3G MIMOSpatial correlationComputer scienceMIMOlcsh:TK7800-8360TopologyCommunications systemlcsh:Telecommunicationlaw.inventionChannel capacityNarrowbandRelaylawlcsh:TK5101-6720Mobile stationVDP::Technology: 500::Information and communication technology: 550::Telecommunication: 552Computer Science::Networking and Internet ArchitectureFadingElectrical and Electronic EngineeringComputer Science::Information Theorybusiness.industrylcsh:ElectronicsHardware and ArchitectureSignal Processingmobile-to-mobile fading channels MIMO channels space-time cross-correlation functionsTelecommunicationsbusinessCommunication channelEURASIP Journal on Advances in Signal Processing
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Non-convex power allocation games in MIMO cognitive radio networks

2013

Consideramos un escenario de reparto del espectro, basado en la detección, en una red de radio cognitiva MIMO donde el objetivo general es maximizar el rendimiento total de cada usuario de radio cognitiva optimizando conjuntamente la operación de detección y la asignación de potencia en todos los canales, bajo una restricción de interferencia para los usuarios primarios. Los problemas de optimización resultantes conducen a un juego no convexo, que presenta un nuevo desafío a la hora de analizar los equilibrios de este juego. Con el fin de hacer frente a la no convexidad del juego, utilizamos un nuevo concepto relajado de equilibrio, el equilibrio cuasi-Nash (QNE). Se demuestran las condicio…

3G MIMOnon-cooperative gamesComputer Science::Computer Science and Game TheoryMathematical optimization:CIENCIAS TECNOLÓGICAS [UNESCO]021103 operations researchOptimization problemComputer scienceMIMO0211 other engineering and technologies020206 networking & telecommunicationsThroughput02 engineering and technologyUNESCO::CIENCIAS TECNOLÓGICASCognitive radio0202 electrical engineering electronic engineering information engineeringquasi-Nash equilibriumResource allocationGame theoryInterior point methodcognitive radio network
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Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

2021

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original …

3d printedMaterials science3D printing3d modelFDM printing030204 cardiovascular system & hematologylcsh:TechnologyArticle030218 nuclear medicine & medical imaginglaw.invention03 medical and health sciencesDICOM3D engineering0302 clinical medicinelawStl fileGeneral Materials Sciencelcsh:Microscopycoronarylcsh:QC120-168.85anatomical modellcsh:QH201-278.5Fused deposition modelingaccuracyPolyJet printinglcsh:Tbusiness.industryAnatomy3D printingPatient specificaortalcsh:TA1-2040lcsh:Descriptive and experimental mechanicslcsh:Electrical engineering. Electronics. Nuclear engineeringlcsh:Engineering (General). Civil engineering (General)Wall thicknessbusinesslcsh:TK1-9971Materials
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Problem Space Identification for Developing Virtual Reality Learning Environments

2021

Our study argues that the extant literature on virtual reality-based learning environments (VRLEs) currently lacks proper definitions and context descriptions for a problem space, which is fundamental for conducting design science research (DSR). Without properly conducted problem space identification, the most pivotal problems cannot be identified resulting solutions lacking validity and unreliable evaluations. This is a major challenge for the DSR in the educational field, but also for the research on VRLEs. The purpose of this paper is to introduce a novel DSR method to support rigorous problem space identification, which would allow rigorous and profound problem space analysis. The inst…

4112 ForestrykoulutusteknologiaComputer scienceDesign-based researchkehittämistutkimuseducational design research02 engineering and technologyVirtual realityEducational design researchvirtual reality learning environmentsvirtuaalitodellisuus03 medical and health sciencesIdentification (information)0302 clinical medicineHuman–computer interactiondesign science research0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processing030212 general & internal medicineDesign science research512 Business and Managementdesign based research1172 Environmental sciencesProblem space
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Effect of high temperature annealing (T > 1650 °C) on the morphological and electrical properties of p-type implanted 4H-SiC layers

2019

This work reports on the effect of high temperature annealing on the electrical properties of p-type implanted 4H-SiC. Ion implantations of Aluminum (Al) at different energies (30-200 keV) were carried out to achieve 300 nm thick acceptor box profiles with a concentration of about 10(20) at/cm(3). The implanted samples were annealed at high temperatures (1675-1825 degrees C). Morphological analyses of the annealed samples revealed only a slight increase of the surface roughness RMS up to 1775 degrees C, while this increase becomes more significant at 1825 degrees C (RMS = 1.2 nm). Room temperature Hall measurements resulted in a hole concentration in the range 0.65-1.34 x 10(18)/cm(3) and m…

4H-SiCMaterials scienceFabricationAnnealing (metallurgy)Analytical chemistrychemistry.chemical_element02 engineering and technologyActivation energy01 natural sciencesIonAluminium0103 physical sciencesSurface roughnessGeneral Materials ScienceElectrical measurements010302 applied physicsCondensed Matter - Materials ScienceMechanical EngineeringPhysics - Applied Physics021001 nanoscience & nanotechnologyCondensed Matter PhysicsAcceptorPost implantation annealingchemistryMechanics of MaterialsElectrical activationp-type implantation0210 nano-technologyMaterials Science in Semiconductor Processing
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A flexible and reconfigurable 5G networking architecture based on context and content information

2017

The need for massive content delivery is a consolidated trend in mobile communications, and will even increase for next years. Moreover, while 4G maturity and evolution is driven by video contents, next generation (5G) networks will be dominated by heterogeneous data and additional massive diffusion of Internet of Things (IoT). The current network architecture is not sufficient to cope with such traffic, which is heterogeneous in terms of latency and QoS requirements, and variable in space and time. This paper proposes architectural advances to endow the network with the necessary flexibility helping to adapt to these varying traffic needs by providing content and communication services whe…

5G networkingComputer scienceflexible HW/SW platforms 5G networking context-awareness content-centric networks reconfigurability050801 communication & media studies02 engineering and technologyflexible HW/SW platforms 5G networking context-awareness; content-centric networks; reconfigurability.0508 media and communications0202 electrical engineering electronic engineering information engineeringReference architectureArchitectureNetwork architecturebusiness.industrySettore ING-INF/03 - TelecomunicazioniQuality of service05 social sciencesflexible HW/SW platformscontent-centric networkscontext-awarenessReconfigurability020206 networking & telecommunicationsApplications architectureMobile telephonybusinessreconfigurability5GComputer network
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Designing the 5G network infrastructure: a flexible and reconfigurable architecture based on context and content information

2018

5G networks will have to offer extremely high volumes of content, compared to those of today’s. Moreover, they will have to support heterogeneous traffics, including machine-to-machine, generated by a massive volume of Internet-of-Things devices. Traffic demands will be variable in time and space. In this work, we argue that all this can be achieved in a cost-effective way if the network is flexible and reconfigurable. We present the Flex5Gware network architecture, designed to meet the above requirements. Moreover, we discuss the links between flexibility and reconfigurability, on the one side, and context awareness and content awareness, on the other; we show how two of the building…

5G networkingStandardizationFlexible HW/SW platformComputer Networks and CommunicationsComputer scienceContext-awareneDistributed computinglcsh:TK7800-8360050801 communication & media studies02 engineering and technologylcsh:Telecommunication0508 media and communicationslcsh:TK5101-6720flexible HW/SW platforms 5G networking context-awareness; content-awareness; reconfigurability0202 electrical engineering electronic engineering information engineeringContext awarenessArchitecturecontent-awarenessNetwork architectureAccess networklcsh:Electronicsflexible HW/SW platforms05 social sciencescontext-awarenessReconfigurabilityControl reconfigurationComputer Science Applications1707 Computer Vision and Pattern Recognition020206 networking & telecommunicationsComputer Science ApplicationsContent-awareneSignal Processingreconfigurability5GEURASIP Journal on Wireless Communications and Networking
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From Feynman–Kac formulae to numerical stochastic homogenization in electrical impedance tomography

2016

In this paper, we use the theory of symmetric Dirichlet forms to derive Feynman–Kac formulae for the forward problem of electrical impedance tomography with possibly anisotropic, merely measurable conductivities corresponding to different electrode models on bounded Lipschitz domains. Subsequently, we employ these Feynman–Kac formulae to rigorously justify stochastic homogenization in the case of a stochastic boundary value problem arising from an inverse anomaly detection problem. Motivated by this theoretical result, we prove an estimate for the speed of convergence of the projected mean-square displacement of the underlying process which may serve as the theoretical foundation for the de…

65C05Statistics and Probability65N21stochastic homogenizationquantitative convergence result01 natural sciencesHomogenization (chemistry)78M40general reflecting diffusion process010104 statistics & probabilitysymbols.namesakeFeynman–Kac formula60J4535Q60Applied mathematicsFeynman diagramBoundary value problemSkorohod decomposition0101 mathematicsElectrical impedance tomographyBrownian motionMathematicsrandom conductivity field65N75010102 general mathematicsFeynman–Kac formulaLipschitz continuityBounded functionstochastic forward problemsymbols60J55Statistics Probability and Uncertainty60H30electrical impedance tomographyThe Annals of Applied Probability
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Learning automata based energy-efficient AI hardware design for IoT applications

2020

Energy efficiency continues to be the core design challenge for artificial intelligence (AI) hardware designers. In this paper, we propose a new AI hardware architecture targeting Internet of Things applications. The architecture is founded on the principle of learning automata, defined using propositional logic. The logic-based underpinning enables low-energy footprints as well as high learning accuracy during training and inference, which are crucial requirements for efficient AI with long operating life. We present the first insights into this new architecture in the form of a custom-designed integrated circuit for pervasive applications. Fundamental to this circuit is systematic encodin…

7621003Computer scienceGeneral MathematicsDesign flow1006General Physics and Astronomy02 engineering and technologySoftwareRobustness (computer science)0202 electrical engineering electronic engineering information engineeringField-programmable gate arrayenergy efficiencyHardware architectureArtificial neural networkLearning automata52business.industryTsetlin machines020208 electrical & electronic engineeringGeneral Engineeringartificial intelligence hardware designArticlesneural networksAutomation020202 computer hardware & architecturebusinessComputer hardwareResearch ArticlePhilosophical transactions. Series A, Mathematical, physical, and engineering sciences
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Thermomineral waters of Greece: geochemical characterization

2020

75 °C). In terms of pH most results vary from 5.5 to 823 °C) ii) warm (23 40 °C) iii) thermal (40 75 °C) and iv) hyperthermal (&gtfew springs show either very low pH (&lt10) proposing serpentinization processes. Regarding TDS concentrations collected waters can be subdivided into low salinity (up to 1.5 g/L) brackish (up to 20 g/L) and saline (up to 43 g/L). The medium high salinities can be justified by mixing with sea water and/or strong waterrock interaction processes. Isotope composition of O and H ranges from 12.7 to +2.7 ‰ SMOW and from 91 to +12 ‰ SMOW respectively and is generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Only few water samples show a positive shift for δ18O possibly related to high temperature waterrock interaction processes. Carbon dioxide (18 997000 μmol/mol) or N2 (1100 989000 μmol/mol) or CH4 (&ltMany geothermal areas of Greece are located in regions affected by Miocene or Quaternary volcanism and in continental basins characterised by elevated heat flow. Moreover the majority of them is found along the coast as well as in islands of the Aegean Sea and thus thermal water is often brackish to saline due to marine intrusion into costal aquifer. In the present study almost 300 thermal and cold mineral water samples were collected along the Hellenic territory with their physicochemical parameters (temperature pH electrical conductivity and Eh) and the amount of bicarbonates (titration with 0.1N HCl) being determined in situ. Additionally gases found either in free or dissolved phase were sampled. Both water and gas samples were analysed at the INGVPa laboratories for major ions (Ion Chromatography) silica (Inductively Coupled Plasma Optical Emission Spectrometry) chemical composition of free and dissolved gases (Gas Chromatography) water isotopes (O and H) and carbon and helium isotopes of free and dissolved gases (Mass Spectrometry). The temperature of the investigated waters ranges from 6.5 to 98°C pH from 1.96 to 11.98 whilst Total Dissolved Solids (TDS) from 0.06 to 43 g/L. Based on the temperature parameter waters can be divided into four groups: i) cold (&lt0.5 913000 μmol/mol) are the prevailing gas species found in the studied sites. The δ13CCO2 values ranged from 20.1 to +8.5 ‰ whilst the isotope ratio of He from 0.21 to 6.71 R/RA.4) suggesting interaction with H2Srich gases or very high pH values (&gtSettore GEO/08 - Geochimica E Vulcanologia
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