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CompactChain:an efficient stateless chain for UTXO-model blockchain

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Frontiers of Computer science 2024年第2期18卷 167-179页

作者： b swaroopa REDDY T Uday Kiran REDDY Department of Electrical Engineering Indian Institute of Technology HyderabadHyderabadTelangana 502285India

In this work,we propose a stateless blockchain called CompactChain,which compacts the entire state of the UTXO(Unspent Transaction Output)based blockchain systems into two RsA *** first accumulator is called Transaction Output(TXO)commitment which represents the TXO *** second one is called spent Transaction Output(sTXO)commitment which represents the sTXO *** this work,we discuss three algorithms:(i)To update the TXO and sTXO commitments by the *** miner also provides the proofs for the correctness of the updated commitments;(ii)To prove the transaction’s validity by providing a membership witness in TXO commitment and non-membership witness against sTXO commitment for a coin being spent by a user;(iii)To update the witness for the coin that is not yet spent;The experimental results evaluate the performance of the CompactChain in terms of time taken by a miner to update the commitments and time taken by a validator to verify the commitments and validate the *** compare the performance of CompactChain with the existing state-of-the-art works on stateless *** shows a reduction in commitments update complexity and transaction witness size which inturn reduces the mempool size and propagation latency without compromising the system throughput(Transactions per second(TPs)).

关键词： stateless blockchain RsA Accumulator sTXO commitment TXO commitment UTXO Non-interactive Proof of Exponentiation(NI-PoE) Transactions per second(TPs)

Tribological behavior of lubricant-impregnated porous polyimide

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Friction 2024年第4期12卷 711-725页

作者： Jinbang LI Ningning ZHOU Janet s.s.WONG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication

Closing the Experiment-Modeling-Perturbation Loop in Whole-brain Neuroscience

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Neuroscience bulletin 2024年第8期40卷 1212-1214页

作者： Misha b.Ahrens Janelia Research Campus Howard Hughes Medical InstituteAshburnVAUSA

Understanding the mechanisms by which the central nervous system processes information,forms memories,makes decisions,and executes actions is a challenging *** is an interdisciplinary field in which cell biology,anatomy,network theory,and other scientific disciplines come together to jointly push our knowledge of brain function forward.

关键词： execute knowledge jointly

Old-growth mixed dipterocarp forests show variable losses and gains in aboveground biomass and standing carbon over forty years

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Forest Ecosystems 2024年第1期11卷 14-23页

作者： sisira Ediriweera Champika bandara Tithira Lakkana shanika Jayasinghe David Woodbury Arun Dayanandan b.M.P.singhakumara Xiangcheng Mi I.A.U.N.Gunatilleke C.V.s.Gunatilleke Mark sAshton Department of science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest school Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Department of Forestry and Environmental science University of Sri JayewardenepuraNugegodaSri Lanka state Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing100093China botany Department University of PeradeniyaPeradeniyaSri Lanka

background:No studies have documented long-term trends in aboveground biomass(AGb)for mixed-dipterocarp forests(MDF),the dominant rain forest type in tropical wet equatorial *** our study,we sought to document such trends over forty years across three sites representing lowland to lower montane ***:To do this,we established fifty 100 m×25 m plots in 1978 across three sites sampled along an elevation gradient,identified as mature old-growth *** measured trees for diameter at breast height that we identified to species and *** took wood samples to calculate species wood-specific *** re-measured plots in 1998 and again in ***:We show standing AGb for all sites combined to be 517.52 Mg·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 Mg·ha^(-1).No differences exist among sites in AGb primarily because of considerable within site variation;but interactions of time with site show declines across sites were not uniform,one remained about the *** few species represented a high proportion of the AGb with the top five species comprising between 34%and 65%,depending upon site and year *** species,Mesua nagassarium,represented a disproportionately large amount of AGb and decline over time,particularly at the low elevation ***:Our results are directly relevant to estimating AGb and standing carbon sequestered in *** study is the first to demonstrate varying but overall,declining trends in amounts of AGb among forests making predictions of biomass and standing carbon in MDF difficult over wide regions.

关键词： Western ghats shorea spp. southeast Asia sri Lanka Tropical rain forest Wood specific gravity

Enhancing fatigue performance of AZ31 magnesium alloy components fabricated by cold metal transfer-based wire arc directed energy deposition through LPb

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Journal of Magnesium and Alloys 2024年第4期12卷 1638-1662页

作者： shambhu Kumar Manjhi srikanth bontha A.s.s.balan Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkalSrinivasanagarMangaloreKarnataka 575025India

Cold Metal Transfer-based Wire Arc Directed Energy Deposition(CMT-WA-DED)presents a promising avenue for the rapid fabrication of components crucial to automotive,shipbuilding,and aerospace ***,the susceptibility to fatigue of CMT-WA-DED-produced AZ31 Mg alloy components has impeded their widespread adoption for critical load-bearing *** this study,a comprehensive investigation into the fatigue behaviour of WA-DED-fabricated AZ31 Mg alloy has been carried out and compared to commercially available wrought AZ31 *** findings indicate that the as-deposited parts exhibit a lower fatigue life than wrought Mg alloy,primarily due to poor surface finish,tensile residual stress,porosity,and coarse grain microstructure inherent in the WA-DED *** Plasticity burnishing(LPb)treatment is applied to mitigate these issues,which induce significant plastic deformation on the *** treatment resulted in a remarkable improvement of fatigue life by 42%,accompanied by a reduction in surface roughness,grain refinement and enhancement of compressive residual stress ***,during cyclic deformation,WA-DED specimens exhibited higher plasticity and dislocation density compared to both wrought and WA-DED+LPb specimens.A higher fraction of Low Angle Grain boundaries(LAGbs)in WA-DED specimens contributed to multiple crack initiation sites and convoluted crack paths,ultimately leading to premature *** contrast,wrought and WA-DED+LPb specimens displayed a higher percentage of High Angle Grain boundaries(HAGbs),which hindered dislocation movement and resulted in fewer crack initiation sites and less complex crack paths,thereby extending fatigue *** findings underscore the effectiveness of LPb as a post-processing technique to enhance the fatigue performance of WA-DED-fabricated AZ31 Mg alloy *** study highlights the importance of LPb surface treatment on AZ31 Mg components produced by CMT-WA-DED to remove surface d

关键词： Wire arc additive manufacturing AZ31 Mg alloy Low plasticity burnishing Low cycle fatigue test strain amplitude

Ren-integrable and ren-symmetric integrable systems

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Communications in Theoretical Physics 2024年第3期76卷 62-69页

作者： s Y Lou school of Physical science and Technology Ningbo UniversityNingbo315211China

A new type of symmetry,ren-symmetry,describing anyon physics and corresponding topological physics,is ***-symmetry is a generalization of super-symmetry which is widely applied in super-symmetric physics such as super-symmetric quantum mechanics,super-symmetric gravity,super-symmetric string theory,super-symmetric integrable systems and so *** and Grassmann numbers are,in some sense,dual conceptions,and it turns out that these conceptions coincide for the ren situation,that is,a similar conception of ren-number(R-number)is devised for *** particular,some basic results of the R-number and ren-symmetry are exposed which allow one to derive,in principle,some new types of integrable systems including ren-integrable models and ren-symmetric integrable *** examples of ren-integrable KdV-type systems and ren-symmetric KdV equations are explicitly given.

关键词： symmetries integrable systems anyon physics extended supersymmetry ren-symmetry

AutoRhythmAI: A Hybrid Machine and Deep Learning Approach for Automated Diagnosis of Arrhythmias

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Computers, Materials & Continua 2024年第2期78卷 2137-2158页

作者： s.Jayanthi s.Prasanna Devi Department of Computer science and Engineering SRM Institute of Science and Technology-Vadapalani CampusChennaiTamil NaduIndia

In healthcare,the persistent challenge of arrhythmias,a leading cause of global mortality,has sparked extensive research into the automation of detection using machine learning(ML)***,traditional ML and AutoML approaches have revealed their limitations,notably regarding feature generalization and automation *** glaring research gap has motivated the development of AutoRhythmAI,an innovative solution that integrates both machine and deep learning to revolutionize the diagnosis of *** approach encompasses two distinct pipelines tailored for binary-class and multi-class arrhythmia detection,effectively bridging the gap between data preprocessing and model *** validate our system,we have rigorously tested AutoRhythmAI using a multimodal dataset,surpassing the accuracy achieved using a single dataset and underscoring the robustness of our *** the first pipeline,we employ signal filtering and ML algorithms for preprocessing,followed by data balancing and split for *** second pipeline is dedicated to feature extraction and classification,utilizing deep learning ***,we introduce the‘RRI-convoluted trans-former model’as a novel addition for binary-class *** ensemble-based approach then amalgamates all models,considering their respective weights,resulting in an optimal model *** our study,the VGGRes Model achieved impressive results in multi-class arrhythmia detection,with an accuracy of 97.39%and firm performance in precision(82.13%),recall(31.91%),and F1-score(82.61%).In the binary-class task,the proposed model achieved an outstanding accuracy of 96.60%.These results highlight the effectiveness of our approach in improving arrhythmia detection,with notably high accuracy and well-balanced performance metrics.

关键词： Automated machine learning neural networks deep learning arrhythmias

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Jumping droplets

Droplet 2024年第2期3卷 3-33页

作者： Jonathan b.boreyko Department of Mechanical Engineering Virginia TechBlacksburgVirginiaUSA

When microdroplets with quasi-spherical contact angles coalesce together on a low-adhesion substrate,the capillary-inertial expansion of the liquid bridge induces a dramatic out-of-plane jumping event due to symmetry *** the onset of merging,droplet jumping initiates after a capillary-inertial time scale of tci∼1–100μs with characteristic jumping speeds of order vj∼0.1m/*** coalescenceinduced jumping-droplet effect is most commonly observed among a population of growing dew droplets on a superhydrophobic condenser,but can also occur by colliding deposited droplets together or during droplet sliding on fog *** this review,we cover the historical development of capillary-inertial jumping droplets,summarize the decade-long effort to rationalize the ultra-low energy conversion efficiency and critical droplet size of the phenomenon,and then present 15 variations on a theme of ***-inertial jumping droplets are not only a visceral illustration of the surprising power of surface tension at the microscale but they also have the potential to enhance phase-change heat transfer,enable selfcleaning surfaces,combat frost formation,harvest energy,and govern the rate of disease spread for wheat crops.

关键词： capillary illustration rational

On the Features of Thermal Convection in a Compressible Gas

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Fluid Dynamics & Materials Processing 2024年第5期20卷 957-974页

作者： Igor b.Palymskiy Physics Department Siberian State University of Telecommunications and Information SciencesNovosibirsk City630102Russia Physics Department Siberian State University of Geosystems and TechnologiesNovosibirsk City630108Russia

The fully nonlinear equations of gas dynamics are solved in the framework of a numerical approach in order to study the stability of the steady mode of Rayleigh-bénard convection in compressible,viscous and heat-conducting gases encapsulated in containers with no-slip boundaries and isothermal top and bottom *** initial linear temperature profile is assumed.A map of the possible convective modes is presented assuming the height of the region and the value of the temperature gradient as influential *** a relatively small height,isobaric convection is found to take place,which is taken over by an adiabatic mode when the height exceeds the critical value,or by a super-adiabatic mode in case of a relatively high temperature *** the adiabatic mode,convective flow develops due to adiabatic processes given a stable initial *** analytic formula for the critical height of the region is derived taking into account and neglecting the dependence of the gas viscosity on the ***,an analytic formula is obtained for the upper boundary of the region of applicability of the boussinesq approximation for incompressible *** models for compressible gases are relevant to practical situations such as the study of convective flows in spatially extended gas mixtures when dealing with safety issues related to hydrocarbons stored in gas stations.A dangerous situation arises when the tank is almost empty but some hydrocarbon is left at the bottom of the *** the presence of convective flows,the vaporized fuel is mixed with the oxidizer(air)forming a gas-vapor ***,if the volumetric concentration of fuel vapor(hydrocarbon)is in the interval between the lower and upper concentration limits of ignition,then the gas-vapor mixture becomes explosive and any accidental spark is sufficient to cause an emergency.

关键词： Rayleigh-bénard convection gas stable stratification unstable stratification temperature gradient