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paludification reduces black spruce growth rate but does not alter tree water use efficiency in Canadian boreal forested peatlands

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Forest Ecosystems 2021年第2期8卷 373-386页

作者： Joannie Beaulne Étienne Boucher Michelle Garneau gabriel Magnan Geotop Research Center Université du Québec à MontréalMontréalQuébec H3C 3P8Canada Department of Geography Université du Québec à MontréalMontréalQuébec H3C 3P8Canada GRIL-UQAM Université du Québec à MontréalQuébec H3C 3P8Canada Centre d'études nordiques Université LavalMontréalQuébec G1V 0A6Canada

Background:Black spruce(picea mariana(Mill.)BSp)-forested peatlands are widespread ecosystems in boreal North America in which peat accumulation,known as the paludification process,has been shown to induce forest growth *** continuously evolving environmental conditions(e.g.,water table rise,increasing peat thickness)in paludified forests may require tree growth mechanism adjustments over *** this study,we investigate tree ecophysiological mechanisms along a paludification gradient in a boreal forested peatland of eastern Canada by combining peat-based and tree-ring *** and oxygen stable isotopes in tree rings are used to document changes in carbon assimilation rates,stomatal conductance,and water use *** addition,paleohydrological analyses are performed to evaluate the dynamical ecophysiological adjustments of black spruce trees to site-specific water table ***:Increasing peat accumulation considerably impacts forest growth,but no significant differences in tree water use efficiency(iWUE)are found between the study ***-ring isotopic analysis indicates no iWUE decrease over the last 100 years,but rather an important increase at each site up to the 1980 s,before iWUE ***,inferred basal area increments do not reflect such ***,iWUE variations do not reflect tree ecophysiological adjustments required by changes in growing *** water table variations induce no changes in ecophysiological mechanisms,but a synchronous shift in iWUE is observed at all sites in the mid-1980 ***:Our study shows that paludification induces black spruce growth decline without altering tree water use efficiency in boreal forested *** findings highlight that failing to account for paludification-related carbon use and allocation could result in the overestimation of aboveground biomass production in paludified *** research on carbon allocation strategies is of utmos

关键词： Black spruce growth Boreal biome Carbon allocation Ecophysiological mechanisms Forested peatland paludification Stable isotope Water use efficiency

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Magnetopause properties at the dusk magnetospheric flank from global magnetohydrodynamic simulations,the kinetic Vlasov equilibrium,and in situ observations--potential implications for SMILE

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Earth and planetary physics 2024年第1期8卷 222-233页

作者： Marius Echim Costel Munteanu gabriel Voitcu Eliza Teodorescu Institute of Space Science Măgurele 077125Romania Royal Belgian Institute for Space Aeronomy 1180 BrusselsBelgium Solar-Terrestrial Centre of Excellence(STCE) 1180 BrusselsBelgium

We derived the properties of the terrestrial magnetopause(Mp)from two modeling approaches,one global–fluid,the other local–kinetic,and compared the results with data collected in situ by the Magnetospheric Multiscale 2(MMS2)*** used global magnetohydrodynamic(MHD)simulations of the Earth’s magnetosphere(publicly available from the NASA-CCMC[National Aeronautics and Space Administration–Community Coordinated Modeling Center])and local Vlasov equilibrium models(based on kinetic models for tangential discontinuities)to extract spatial profiles of the plasma and field variables at the Earth’s *** global MHD simulations used initial solar wind conditions extracted from the OMNI database at the time epoch when the MMS2 observes the *** kinetic Vlasov model used asymptotic boundary conditions derived from the same in situ MMS measurements upstream or downstream of the *** global MHD simulations provide a three-dimensional image of the magnetosphere at the time when the MMS2 crosses the *** Vlasov model provides a one-dimensional local view of the Mp derived from first principles of kinetic *** MMS2 experimental data also serve as a reference for comparing and validating the numerical simulations and *** found that the Mp transition layer formed in global MHD simulations was generally localized closer to the Earth(roughly by one Earth radius)from the position of the real Mp observed by the *** also found that the global MHD simulations overestimated the thickness of the Mp transition by one order of magnitude for three analyzed variables:magnetic field,density,and tangential *** Mp thickness derived from the local Vlasov equilibrium was consistent with observations for all three of these *** overestimation of density in the Vlasov equilibrium was reduced compared with the global MHD *** discuss our results in the context of future SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)campaigns for observing

关键词： magnetopause magnetohydrodynamic numerical simulations Vlasov equilibrium Magnetospheric Multiscale observations

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Video streaming distribution over mobile Internet:a survey

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Frontiers of Computer Science 2018年第6期12卷 1039-1059页

作者： Mu WANG Changqiao XU Shijie JIA gabriel-Miro MUNTEAN State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China Academy of Information Technology Luoyang Normal UniversityLuoyang 471934China performance Engineering Laboratory Network Innovations CentreRince InstituteSchool of Electronic EngineeringDublin City UniversityDublin 9Ireland

In recent times, mobile Internet has witnessed the explosive growth of video applications, embracing user-generated content, Internet protocol television (IpTV), live streaming, video-on-demand, video conferencing, and FaceTime-like video communications. The exponential rise of video traffic and dynamic user behaviors have proved to be a major challenge to video resource sharing and delivery in the mobile environment. In this article, we present a survey of state-of-the-art video distribution solutions over the Internet. We first discuss the challenges of mobile peer-to-peer (Mp2p)-based solutions and categorize them into two groups. We discuss the design idea, characteristics, and drawbacks of solutions in each group. We also give a review for solutions of video transmission in wireless heterogeneous networks. Furthermore, we summarize the information-centric networking (ICN)-based video solutions in terms of in-network caching and name-based routing. Finally, we outline the open issues for mobile video systems that require further studies.

关键词： video streaming content distribution resource management mobile Internet

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Improving precision of field inventory estimation of aboveground biomass through an alternative view on plot biomass

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Forest Ecosystems 2020年第4期7卷 760-769页

作者： Christoph Kleinn Steen Magnussen Nils Nölke paul Magdon Juan gabrielÁlvarez-González Lutz Fehrmann César pérez-Cruzado Forest Inventory and Remote Sensing Georg-August-Universität Göttingen37077 GöttingenGermany. Canadian Forest Service Natural Resources CanadaVictoriaBC V8Z 1M5Canada. Department of Agroforestry Engineering University of Santiago de CompostelaE-27002 LugoSpain

We contrast a new continuous approach(CA)for estimating plot-level above-ground biomass(AGB)in forest inventories with the current approach of estimating AGB exclusively from the tree-level AGB predicted for each tree in a plot,henceforth called DA(discrete approach).With the CA,the AGB in a forest is modelled as a continuous surface and the AGB estimate for a fixed-area plot is computed as the integral of the AGB surface taken over the plot *** with the CA,the portion of the biomass of in-plot trees that extends across the plot perimeter is ignored while the biomass from trees outside of the plot reaching inside the plot is *** use a sampling simulation with data from a fully mapped two hectare area to illustrate that important differences in plot-level AGB estimates can *** CA-based estimates of mean AGB should be less variable than those derived from the *** realized,this difference translates to a higher precision from field sampling,or a lower required sample *** our case study with a target precision of 5%(*** standard error of the estimated mean AGB),the CA required a 27.1%lower sample size for small plots of 100 m2 and a 10.4%lower sample size for larger plots of 1700 *** examined sampling induced errors only and did not yet consider model *** discuss practical issues in implementing the CA in field inventories and the potential in applications that model biomass with remote sensing *** CA is a variation on a plot design for above-ground forest biomass;as such it can be applied in combination with any forest inventory sampling design.

关键词： Branch biomass Foliage biomass Stem biomass Biomass surface plots Sampling surfaces Standard error of estimation

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predicting electronic structures at any length scale with machine learning

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npj Computational Materials 2023年第1期9卷 1176-1185页

作者： Lenz Fiedler Normand A.Modine Steve Schmerler Dayton J.Vogel gabriel A.popoola Aidan p.Thompson Sivasankaran Rajamanickam Attila Cangi Center for Advanced Systems Understanding D-02826 GörlitzGermany Helmholtz-Zentrum Dresden-Rossendorf D-01328 DresdenGermany Computational Materials and Data Science Sandia National Laboratories1515 Eubank BlvdAlbuquerque 87123 NMUSA Elder Research Inc.300 West Main StreetCharlottesville 22903 VAUSA Center for Computing Research Sandia National Laboratories1515 Eubank BlvdAlbuquerque 87123 NMUSA

The properties of electrons in matter are of fundamental *** give rise to virtually all material properties and determine the physics at play in objects ranging from semiconductor devices to the interior of giant gas *** and simulation of such diverse applications rely primarily on density functional theory(DFT),which has become the principal method for predicting the electronic structure of *** DFT calculations have proven to be very useful,their computational scaling limits them to small *** have developed a machine learning framework for predicting the electronic structure on any length *** shows up to three orders of magnitude speedup on systems where DFT is tractable and,more importantly,enables predictions on scales where DFT calculations are *** work demonstrates how machine learning circumvents a long-standing computational bottleneck and advances materials science to frontiers intractable with any current solutions.

关键词： electronic interior frontier

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Anthropometrics and electromyography as predictors for maximal voluntary isometric arm strength

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Journal of Sport and Health Science 2012年第2期1卷 107-113页

作者： Lara A.Green David A.gabriel Department of Kinesiology Brock UniversitySt.CatharinesON L2S 3A1Canada

Background:Muscular strength can be conceptually determined by two components:muscle activation and *** activation by the central nervous system can be measured by surface electromyography(sEMG).Muscular size reflects the amount of contractile protein within a skeletal muscle and can be estimated by anthropometric *** purpose of this study was to determine the relative contributions of size parameters and muscle activation to the prediction of maximal voluntary isometric elbow flexion strength. Methods:A series of anthropometric measurements were taken from 96 *** and root-mean-square(RMS) of the sEMG from the biceps brachii were averaged across three maximal voluntary isometric contractions.A multiple linear regression analysis was performed based on a pearson's correlation matrix. Results:Body weight(BW) accounted for 39.1% and 27.3% in males and females,respectively,and was the strongest predictor of strength for *** length(L3) was the strongest predictor of strength in females(partial R^2 = 0.391).Elbow circumference(ELB) accounted for a significant(p prediction equation included BW,L3,and ELB accounting for 55.6% and 58.5% of the variance in males and females,respectively. Conclusion:Anthropometrics provide a strong prediction equation for the estimation of isometric elbow flexion *** activation,as measured by sEMG activity,accounted for a significant(p prediction equations,however,its contribution was comparable to an additional anthropometric variable.

关键词： Biceps brachii Biomechanics Gender differences Multiple linear regression Muscle force

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Optimal Confidential Mechanisms in Smart City Healthcare

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Computers, Materials & Continua 2022年第3期70卷 4883-4896页

作者： R.Gopi p.Muthusamy p.Suresh C.G.gabriel Santhosh Kumar Irina V.pustokhina Denis A.pustokhin K.Shankar Department of Computing Science and Engineering Dhanalakshmi Srinivasan Engineering CollegePerambalur621212India School of Computing Science and Engineering Galgotias UniversityNCRDelhi203201India Department of Computer Science and Engineering KPR Institute of Engineering and TechnologyCoimbatore641407India Department of Electrical and Electronics Engineering K.Ramakrishnan College of EngineeringTiruchirappalli621112India Department of Entrepreneurship and Logistics Plekhanov Russian University of EconomicsMoscow117997Russia Department of Logistics State University of ManagementMoscow109542Russia Department of Computer Applications Alagappa UniversityKaraikudi630001India

Smart City Healthcare(SHC2)system is applied in monitoring the patient at home while it is also expected to react to their needs in a timely *** system also concedes the freedom of a *** is a part of this system and it helps in providing care to the *** healthcare devices are trustworthy since it almost certainly recognizes the potential intensifications at very early stage and alerts the patients and medical experts to such an extent that they are provided with immediate *** methodologies exhibit few shortcomings in terms of computational complexity,cost and data ***,the current research article examines SHC2 security through LightWeight Cipher(LWC)with Optimal S-Box model in pRESENT *** procedure aims at changing the sub bytes in which a single function is connected with several bytes’information to upgrade the security level through Swam *** key contribution of this research article is the development of a secure healthcare model for smart city using SHC2 security via LWC and Optimal S-Box *** study used a nonlinear layer and single 4-bit S box for round configuration after verifying SHC2 information,constrained by Mutual Authentication(MA).The security challenges,in healthcare information systems,emphasize the need for a methodology that immovably concretes the *** methodology should act practically,be an effective healthcare framework that depends on solidarity and adapts to the developing *** service providers integrated the IoT applications and medical services to offer individuals,a seamless technology-supported healthcare *** proposed SHC^(2) was implemented to demonstrate its security levels in terms of time and access *** model was tested under different parameters such as encryption time,decryption time,access time and response time inminimum ***,the level of the model and throughput were analyzed by maximum value i.e.,50Mbp

关键词： Smart city healthcare security block cipher LWC

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A pOSTERIORI ERROR ANALYSIS OF A FULLY-MIXED FINITE ELEMENT METHOD FOR A TWO-DIMENSIONAL FLUID-SOLID INTERACTION pROBLEM

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Journal of Computational Mathematics 2015年第6期33卷 606-641页

作者： Carolina Dominguez gabriel N. Gatica salim meddahi Instituto de Ciencias Fisicas y Matemdticas facultad de ciencias universidad austral de chile Avenida Eduardo Morales Miranda - Campus isla teja valdivia chile CI2 MA and Departamento de Ingenieria Matematica Universidad de concapcion casilla 160 concepcion chile Departamento de Matemdticas Facultad de ciencias universidad de oiede calvo satela s/n oviedo espana

In this paper we develop an a posteriori error analysis of a fully-mixed finite element method for a fluid-solid interaction problem in 2D. The media are governed by the elas-todynamic and acoustic equations in time-harmonic regime, respectively, the transmission conditions are given by the equilibrium of forces and the equality of the corresponding normal displacements, and the fluid is supposed to occupy an annular region surrounding the solid, so that a Robin boundary condition imitating the behavior of the sommerfeld condition is imposed on its exterior boundary. Dual-mixed approaches are applied in both domains, and the governing equations are employed to eliminate the displacenent a of the solid and the pressure p of the fluid. In addition, since both transmission conditions become essential, they are enforced weakly by means of two suitable lahrange multipliers The unknowns of the solid and the fluid are then approximated by a conforming galerkin scheme defined in terms of pEERS elements in the solid, Raviart-Thomas of lowest order in the fluid, and continuous piecewise linear functions on the boundary, As the main con-tribution of this work, we derive a reliable and efficient residual-based a posteriori error estimator for the aforedescribed coupled problem. Some numerical results confirming the properties of the estimator are also reported.

关键词： Mixed finite elements Helmholtz equation Elastodynamic equation A poste- riori error analysis

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Cellular modelling using p systems and process algebra

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progress in Natural Science:Materials International 2007年第4期17卷 375-383页

作者： Francisco J. Romero-Campero Marian Gheorghe gabriel Ciobanu John M. Auld Mario J. pérez-Jiménez Research Group on Natural Computing Department of Computer Science and Artificial IntelligenceUniversity of SevilleAvda.Reina Mercedes41012 SevillaSpain Department of Computer Science The University of Sheffield Regent CourtPortobello StreetSheffield S1 4DPUK Romanian Academy Institute of Computer ScienceBlvd. Carol I nr. 11700505IasiRomania

In this paper various molecular chemical interactions are modelled under different computational paradigms. p systems andπ-calculus are used to describe intra-cellular reactions like protein-protein interactions and ... 详细信息

关键词： cellular modelling p systems process algebra.

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Experimental and numerical study of pseudo-2D circulating fluidized beds

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particuology 2016年第6期14卷 48-59页

作者： Adam Klimanek Wojciech Adamczyk Sirpa Kallio pawet Kozolub gabriel Wecel Institute of Thermal Technology Silesian University of TechnologyKonarskiego 22 44-100 Gliwice Poland Technical Research Centre of Finland Ltd P.O. Box 1000 FI-02044 VTT Finland Amec Foster Wheeler Staszica 31 41-200 Sosnowiec Poland

We present experimental investigations and numerical simulations of a pseudo-2D riser. Experiments were performed for various airflow rates, particle types/diameters, and particle size distributions. pres- sure distributions along the wall of the riser were measured, Additional measurements from a smaller pseudo-2D riser （Kallio et al., 2009; Shah et al., 2012） were used to analyze horizontal solids volume fraction profiles. The experimental data were compared with simulation results carried out using an Euler-Euler approach, A mesh sensitivity study was conducted for numerical simulations and effects associated with simplifying real 3D geometry to a 2D model were examined. In addition, the effect of using an algebraic equation to represent the granular temperature versus a full partial differential equation also was examined for numerical simulations. Results showed small but significant near-wall sensitivity of the flow variables to mesh size. Substantial differences in mean pressure, solids distribution, and solid velocities were obtained, when 2D and 3D simulation results were compared. Finally, applying the simplified granular temperature equation for turbulent fluidization and for dilute-phase transport can lead to incorrect predictions in models,

关键词： Circulating fluidized bed Euler-Euler approachGas-solid flow Kinetic theory of granular flow particle size distribution 2D vs 3D

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