We consider the linear model (1) where V>0 and X are known, n≥p; β∈R^p, and 0<σ~2<∞ are unknown. Consider the problem of estimating Sβ which is linear estimable. Prof. C. R. Rao has given the necessary ...We consider the linear model (1) where V>0 and X are known, n≥p; β∈R^p, and 0<σ~2<∞ are unknown. Consider the problem of estimating Sβ which is linear estimable. Prof. C. R. Rao has given the necessary and sufficient condition that LY is admissible for Sβ within展开更多
The hybrid electromagnetic-triboelectric generator(HETG)is a prevalent device for mechanical energy harvesting.However,the energy utilization efficiency of the electromagnetic generator(EMG)is inferior to that of the ...The hybrid electromagnetic-triboelectric generator(HETG)is a prevalent device for mechanical energy harvesting.However,the energy utilization efficiency of the electromagnetic generator(EMG)is inferior to that of the triboelectric nanogenerator(TENG)at low driving frequencies,which limits the overall efficacy of the HETG.To tackle this issue,a layered hybrid generator consisting of a rotating disk TENG,a magnetic multiplier,and a coil panel is proposed.The magnetic multiplier not only forms the EMG part with its high-speed rotor and the coil panel but also facilitates the EMG to operate at a higher frequency than the TENG through frequency division operation.The systematic parameter optimization of the hybrid generator reveals that the energy utilization efficiency of EMG can be elevated to that of rotating disk TENG.Incorporating a power management circuit,the HETG assumes the responsibility for monitoring the water quality and fishing conditions by collecting low-frequency mechanical energy.The magneticmultiplier-enabled hybrid generator demonstrated in this work offers a universal frequency division approach to improve the overall outputs of any hybrid generator that collects rotational energy,expanding its practical applications in diverse multifunctional self-powered systems.展开更多
When patients having major surgery reach the post-anaesthesia care unit,families naturally assume that they have survived the most dangerous part of the perioperative experience.Their assumption is wrong.Mortality in ...When patients having major surgery reach the post-anaesthesia care unit,families naturally assume that they have survived the most dangerous part of the perioperative experience.Their assumption is wrong.Mortality in the 30 days after surgery is 140 times higher than intraoperative mortality.^([1,2])In fact,if the month after surgery were considered a disease,it would be the world’s third leading cause of death.^([3])展开更多
This paper proposes a new access architecture onmobile cloud,which introduces a middle layer sitting between mobile devices and their cloud infrastructure.This middle layer is composed of cloudlets which are deployed ...This paper proposes a new access architecture onmobile cloud,which introduces a middle layer sitting between mobile devices and their cloud infrastructure.This middle layer is composed of cloudlets which are deployed by cloud services providers,such as wireless network access points(APs),to improve the performance of mobile cloud servicesand be different from traditional mobile operator mode.Then based on this new architecture.we improve our previous(Attribute-basedencryption) ABE access control scheme on cloud for mobile cloud,which is proposed to offload the main amount of computations to the cloudlet as the function of cloud.Simulationresults demonstratethe new access control scheme takes into consideration response time constraints and network statusof access task execution,while satisfying certain network security for mobile cloud.展开更多
In this study,the mechanical properties of the composite plate were considered Gaussian random fields and their effects on the buckling load and corresponding mode shapes were studied by developing a semi-analytical n...In this study,the mechanical properties of the composite plate were considered Gaussian random fields and their effects on the buckling load and corresponding mode shapes were studied by developing a semi-analytical nonintrusive approach.The random fields were decomposed by the Karhunen−Loève method.The strains were defined based on the assumptions of the first-order and higher-order shear-deformation theories.Stochastic equations of motion were extracted using Euler-Lagrange equations.The probabilistic response space was obtained by employing the nonintrusive polynomial chaos method.Finally,the effect of spatially varying stochastic properties on the critical load of the plate and the irregularity of buckling mode shapes and their sequences were studied for the first time.Our findings showed that different shear deformation plate theories could significantly influence the reliability of thicker plates under compressive loading.It is suggested that a linear relationship exists between the mechanical properties’variation coefficient and critical loads’variation coefficient.Also,in modeling the plate properties as random fields,a significant stochastic irregularity is obtained in buckling mode shapes,which is crucial in practical applications.展开更多
Functional surfaces that can control light across the electromagnetic spectrum are highly desirable.Plasmonic nanostructures can assume this role by exhibiting dimension-tunable resonances that span multiple electroma...Functional surfaces that can control light across the electromagnetic spectrum are highly desirable.Plasmonic nanostructures can assume this role by exhibiting dimension-tunable resonances that span multiple electromagnetic regimes.However,changing these structural parameters often impacts the higher-order resonances and spectral features in lower-wavelength domains.In this study,we discuss a cavity-coupled plasmonic system with resonances that are tunable across the 3–5 or 8–14μm infrared bands while retaining near-invariant spectral properties in the visible domain.This result is accomplished by regime-dependent resonance mechanisms and their dependence on independent structural parameters.Through the identification and constraint of key parameters,we demonstrate multispectral data encoding,where images,viewable in the infrared spectral domain,appear as uniform areas of color in the visible domain—effectively hiding the information.Fabricated by large area nanoimprint lithography and compatible with flexible surfaces,the proposed system can produce multifunctional coatings for thermal management,camouflage,and anti-counterfeiting.展开更多
To the Editor:In the past decades,there were at least 31.5 million sepsis patients worldwide.Of these patients,5.3 million sepsis patients face death every year.[1]Studies have shown the mortality from sepsis can be r...To the Editor:In the past decades,there were at least 31.5 million sepsis patients worldwide.Of these patients,5.3 million sepsis patients face death every year.[1]Studies have shown the mortality from sepsis can be reduced by compliance with the surviving sepsis campaign guidelines(C_(ssc)).[2]Compliance with guidelines depends on the execution of the medical team.We assume that the medical quality of the intensive care unit(Q_(ICU))will have an important impact on the C_(ssc).展开更多
PROFESSOR Yitang Zhang, a number theorist at the University of California, Santa Barbara, USA, has posted a paper on arXiv [1] that hints at the possibility that he may have solved the Landau-Siegel zeros conjecture. ...PROFESSOR Yitang Zhang, a number theorist at the University of California, Santa Barbara, USA, has posted a paper on arXiv [1] that hints at the possibility that he may have solved the Landau-Siegel zeros conjecture. He has claimed that he has disproved a weaker version of the Landau-Siegel zeroes conjecture, an important problem related to the hypothesis.The conjecture is that there are solutions to the zeta function that do not assume the form prescribed by the Riemann hypothesis. Inspired by his work, in this Perspective, we would like to discuss about the distribution of zeros of quasi-polynomials for linear time-invariant(LTI) systems with time delays.展开更多
Kerner pointed that the sequence (x1m,x2m,…xnm)converges to （r1,r2,…rn）（m→∞）if the initial approximation (x10, x20, …, xn（0）) is close to （r1, r2,…rn） sufficiently. The convergence of(x1m, x2m,…, xnm) p...Kerner pointed that the sequence (x1m,x2m,…xnm)converges to （r1,r2,…rn）（m→∞）if the initial approximation (x10, x20, …, xn（0）) is close to （r1, r2,…rn） sufficiently. The convergence of(x1m, x2m,…, xnm) produced by （2） from (x10,x20,…,xn（0）) usually cannot be testified because （r1, r2,…,rn） is unknown. The purpose of this paper is to give sufficient conditions for testifying the convergence.展开更多
The tight-binding(TB)method is an ideal candidate for determining electronic and transport properties for a large-scale system.It describes the system as real-space Hamiltonian matrices expressed on a manageable numbe...The tight-binding(TB)method is an ideal candidate for determining electronic and transport properties for a large-scale system.It describes the system as real-space Hamiltonian matrices expressed on a manageable number of parameters,leading to substantially lower computational costs than the ab-initio methods.Since the whole system is defined by the parameterization scheme,the choice of the TB parameters decides the reliability of the TB calculations.The typical empirical TB method uses the TB parameters directly from the existing parameter sets,which hardly reproduces the desired electronic structures quantitatively without specific optimizations.It is thus not suitable for quantitative studies like the transport property calculations.The ab-initio TB method derives the TB parameters from the ab-initio results through the transformation of basis functions,which achieves much higher numerical accuracy.However,it assumes prior knowledge of the basis and may encompass truncation error.Here,a machine learning method for TB Hamiltonian parameterization is proposed,within which a neural network(NN)is introduced with its neurons acting as the TB matrix elements.This method can construct the empirical TB model that reproduces the given ab-initio energy bands with predefined accuracy,which provides a fast and convenient way for TB model construction and gives insights into machine learning applications in physical problems.展开更多
In the following we assume that u(x, t) is a smooth function of x and t, and u( x, t ) and its derivatives of any order with respect to x tend to zero rapidly as x→-∞.
and obtain a result which generalizes the corresponding results of J. L. Kapplan and J. A.Yorke (J. Math. Analy. Appl., 48(1974), 317—324) and Gao Guozhu (Acta Mathematica Sinica, 1985, 1: 35—40). We assume that g a...and obtain a result which generalizes the corresponding results of J. L. Kapplan and J. A.Yorke (J. Math. Analy. Appl., 48(1974), 317—324) and Gao Guozhu (Acta Mathematica Sinica, 1985, 1: 35—40). We assume that g and f of (1) are continuous functions and τ is a positive constant.展开更多
Two quite different Saha equations modified to a two-temperature plasma were proposed and employed in many literatures.In order to clear up this confusion phenomenon lasted for a few decades in the community of therma...Two quite different Saha equations modified to a two-temperature plasma were proposed and employed in many literatures.In order to clear up this confusion phenomenon lasted for a few decades in the community of thermal plasma science and technology,this paper re-examines the thermodynamic derivation of the two-temperature Saha equations.It is pointed out that the modified Saha equation deduced by using the minimum Gibbs or Helmholtz free energy is incorrect for the two-temperature plasma.Instead,a more rigorous derivation is presented here from the basic thermodynamic principle that the entropy in an isolated system always assumes its maximum value at chemical equilibrium.展开更多
文摘We consider the linear model (1) where V>0 and X are known, n≥p; β∈R^p, and 0<σ~2<∞ are unknown. Consider the problem of estimating Sβ which is linear estimable. Prof. C. R. Rao has given the necessary and sufficient condition that LY is admissible for Sβ within
基金the Scientific and Technology Research Program of Chongqing Municipal Education Commission(KJQN202100522,KJQN202200514,and KJQN202100546)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0746),the Dr.“Through Train”Scientific Research Program(CSTB2022BSXM-JCX0091)the Innovation and Entrepreneurship Training Program for college students of Chongqing(S202210637043).
文摘The hybrid electromagnetic-triboelectric generator(HETG)is a prevalent device for mechanical energy harvesting.However,the energy utilization efficiency of the electromagnetic generator(EMG)is inferior to that of the triboelectric nanogenerator(TENG)at low driving frequencies,which limits the overall efficacy of the HETG.To tackle this issue,a layered hybrid generator consisting of a rotating disk TENG,a magnetic multiplier,and a coil panel is proposed.The magnetic multiplier not only forms the EMG part with its high-speed rotor and the coil panel but also facilitates the EMG to operate at a higher frequency than the TENG through frequency division operation.The systematic parameter optimization of the hybrid generator reveals that the energy utilization efficiency of EMG can be elevated to that of rotating disk TENG.Incorporating a power management circuit,the HETG assumes the responsibility for monitoring the water quality and fishing conditions by collecting low-frequency mechanical energy.The magneticmultiplier-enabled hybrid generator demonstrated in this work offers a universal frequency division approach to improve the overall outputs of any hybrid generator that collects rotational energy,expanding its practical applications in diverse multifunctional self-powered systems.
文摘When patients having major surgery reach the post-anaesthesia care unit,families naturally assume that they have survived the most dangerous part of the perioperative experience.Their assumption is wrong.Mortality in the 30 days after surgery is 140 times higher than intraoperative mortality.^([1,2])In fact,if the month after surgery were considered a disease,it would be the world’s third leading cause of death.^([3])
基金supported by National Natural Science Foundation of China(No.U 1405254, 61472092)China Postdoctoral Science Foundation(No.2015M581101)National Science and Technology SupportingFoundation of China(No.2014BAH41B00)
文摘This paper proposes a new access architecture onmobile cloud,which introduces a middle layer sitting between mobile devices and their cloud infrastructure.This middle layer is composed of cloudlets which are deployed by cloud services providers,such as wireless network access points(APs),to improve the performance of mobile cloud servicesand be different from traditional mobile operator mode.Then based on this new architecture.we improve our previous(Attribute-basedencryption) ABE access control scheme on cloud for mobile cloud,which is proposed to offload the main amount of computations to the cloudlet as the function of cloud.Simulationresults demonstratethe new access control scheme takes into consideration response time constraints and network statusof access task execution,while satisfying certain network security for mobile cloud.
文摘In this study,the mechanical properties of the composite plate were considered Gaussian random fields and their effects on the buckling load and corresponding mode shapes were studied by developing a semi-analytical nonintrusive approach.The random fields were decomposed by the Karhunen−Loève method.The strains were defined based on the assumptions of the first-order and higher-order shear-deformation theories.Stochastic equations of motion were extracted using Euler-Lagrange equations.The probabilistic response space was obtained by employing the nonintrusive polynomial chaos method.Finally,the effect of spatially varying stochastic properties on the critical load of the plate and the irregularity of buckling mode shapes and their sequences were studied for the first time.Our findings showed that different shear deformation plate theories could significantly influence the reliability of thicker plates under compressive loading.It is suggested that a linear relationship exists between the mechanical properties’variation coefficient and critical loads’variation coefficient.Also,in modeling the plate properties as random fields,a significant stochastic irregularity is obtained in buckling mode shapes,which is crucial in practical applications.
基金supported by the National Science Foundation(NSF)under grant noECCS-1509729the Northrop Grumman University Research Program。
文摘Functional surfaces that can control light across the electromagnetic spectrum are highly desirable.Plasmonic nanostructures can assume this role by exhibiting dimension-tunable resonances that span multiple electromagnetic regimes.However,changing these structural parameters often impacts the higher-order resonances and spectral features in lower-wavelength domains.In this study,we discuss a cavity-coupled plasmonic system with resonances that are tunable across the 3–5 or 8–14μm infrared bands while retaining near-invariant spectral properties in the visible domain.This result is accomplished by regime-dependent resonance mechanisms and their dependence on independent structural parameters.Through the identification and constraint of key parameters,we demonstrate multispectral data encoding,where images,viewable in the infrared spectral domain,appear as uniform areas of color in the visible domain—effectively hiding the information.Fabricated by large area nanoimprint lithography and compatible with flexible surfaces,the proposed system can produce multifunctional coatings for thermal management,camouflage,and anti-counterfeiting.
基金the National Key R&D Program of China(No.2020YFC0861000)the National Natural Science Foundation of China(No.81801901).
文摘To the Editor:In the past decades,there were at least 31.5 million sepsis patients worldwide.Of these patients,5.3 million sepsis patients face death every year.[1]Studies have shown the mortality from sepsis can be reduced by compliance with the surviving sepsis campaign guidelines(C_(ssc)).[2]Compliance with guidelines depends on the execution of the medical team.We assume that the medical quality of the intensive care unit(Q_(ICU))will have an important impact on the C_(ssc).
基金supported in part by the National Natural Science Foundation of China(NSFC)(61703086)the Fundamental Research Funds for the Central Universities(N2104009)the IAPI Fundamental Research Funds(2013ZCX02-03)。
文摘PROFESSOR Yitang Zhang, a number theorist at the University of California, Santa Barbara, USA, has posted a paper on arXiv [1] that hints at the possibility that he may have solved the Landau-Siegel zeros conjecture. He has claimed that he has disproved a weaker version of the Landau-Siegel zeroes conjecture, an important problem related to the hypothesis.The conjecture is that there are solutions to the zeta function that do not assume the form prescribed by the Riemann hypothesis. Inspired by his work, in this Perspective, we would like to discuss about the distribution of zeros of quasi-polynomials for linear time-invariant(LTI) systems with time delays.
文摘Kerner pointed that the sequence (x1m,x2m,…xnm)converges to （r1,r2,…rn）（m→∞）if the initial approximation (x10, x20, …, xn（0）) is close to （r1, r2,…rn） sufficiently. The convergence of(x1m, x2m,…, xnm) produced by （2） from (x10,x20,…,xn（0）) usually cannot be testified because （r1, r2,…,rn） is unknown. The purpose of this paper is to give sufficient conditions for testifying the convergence.
基金We acknowledge support from the National Natural Science Foundation of China(61874079,62074116,81971702,and 61774113)the Wuhan Research Program of Application Foundation(2018010401011289)and the Luojia Young Scholars Program.
文摘The tight-binding(TB)method is an ideal candidate for determining electronic and transport properties for a large-scale system.It describes the system as real-space Hamiltonian matrices expressed on a manageable number of parameters,leading to substantially lower computational costs than the ab-initio methods.Since the whole system is defined by the parameterization scheme,the choice of the TB parameters decides the reliability of the TB calculations.The typical empirical TB method uses the TB parameters directly from the existing parameter sets,which hardly reproduces the desired electronic structures quantitatively without specific optimizations.It is thus not suitable for quantitative studies like the transport property calculations.The ab-initio TB method derives the TB parameters from the ab-initio results through the transformation of basis functions,which achieves much higher numerical accuracy.However,it assumes prior knowledge of the basis and may encompass truncation error.Here,a machine learning method for TB Hamiltonian parameterization is proposed,within which a neural network(NN)is introduced with its neurons acting as the TB matrix elements.This method can construct the empirical TB model that reproduces the given ab-initio energy bands with predefined accuracy,which provides a fast and convenient way for TB model construction and gives insights into machine learning applications in physical problems.
基金Project supported by the National Natural Foundation of China.
文摘In the following we assume that u(x, t) is a smooth function of x and t, and u( x, t ) and its derivatives of any order with respect to x tend to zero rapidly as x→-∞.
文摘and obtain a result which generalizes the corresponding results of J. L. Kapplan and J. A.Yorke (J. Math. Analy. Appl., 48(1974), 317—324) and Gao Guozhu (Acta Mathematica Sinica, 1985, 1: 35—40). We assume that g and f of (1) are continuous functions and τ is a positive constant.
基金Supported by the National Natural Science Foundation of China under Grant Nos.59676011 and 59836220.
文摘Two quite different Saha equations modified to a two-temperature plasma were proposed and employed in many literatures.In order to clear up this confusion phenomenon lasted for a few decades in the community of thermal plasma science and technology,this paper re-examines the thermodynamic derivation of the two-temperature Saha equations.It is pointed out that the modified Saha equation deduced by using the minimum Gibbs or Helmholtz free energy is incorrect for the two-temperature plasma.Instead,a more rigorous derivation is presented here from the basic thermodynamic principle that the entropy in an isolated system always assumes its maximum value at chemical equilibrium.
