Compressive sensing(CS)is an emerging methodology in computational signal processing that has recently attracted intensive research activities.At present,the basic CS theory includes recoverability and stability:the f...Compressive sensing(CS)is an emerging methodology in computational signal processing that has recently attracted intensive research activities.At present,the basic CS theory includes recoverability and stability:the former quantifies the central fact that a sparse signal of length n can be exactly recovered from far fewer than n measurements via l1-minimization or other recovery techniques,while the latter specifies the stability of a recovery technique in the presence of measurement errors and inexact sparsity.So far,most analyses in CS rely heavily on the Restricted Isometry Property(RIP)for matrices.In this paper,we present an alternative,non-RIP analysis for CS via l1-minimization.Our purpose is three-fold:(a)to introduce an elementary and RIP-free treatment of the basic CS theory;(b)to extend the current recoverability and stability results so that prior knowledge can be utilized to enhance recovery via l1-minimization;and(c)to substantiate a property called uniform recoverability of l1-minimization;that is,for almost all random measurement matrices recoverability is asymptotically identical.With the aid of two classic results,the non-RIP approach enables us to quickly derive from scratch all basic results for the extended theory.展开更多
The issues of event-triggered exponential L1 filtering are studied for a class of networked linear switched systems.An event-triggered mechanism is proposed to enhance resource utilization in transmission,and save the...The issues of event-triggered exponential L1 filtering are studied for a class of networked linear switched systems.An event-triggered mechanism is proposed to enhance resource utilization in transmission,and save the communication cost of systems as well.Then,the filtering error system is reconstructed as a switched delay system with bounded disturbance through the input delay system approach.By resorting to the Lyapunov-Krasovskii functional approach and the average dwell time(ADT)technique,some interesting results are derived to guarantee the exponential stability with a prescribed L1 disturbance rejection level.Further,an event-triggered exponential L1 filter is designed via solving a set of feasible linear matrix inequalities(LMIs).Finally,the efficiency of the proposed results is verified through a numerical example and a PWM-driven boost converter circuit system.展开更多
In this paper,we develop a two-grid method(TGM)based on the FEM for 2D nonlinear time fractional two-term mixed sub-diffusion and diffusion wave equations.A two-grid algorithm is proposed for solving the nonlinear sys...In this paper,we develop a two-grid method(TGM)based on the FEM for 2D nonlinear time fractional two-term mixed sub-diffusion and diffusion wave equations.A two-grid algorithm is proposed for solving the nonlinear system,which consists of two steps:a nonlinear FE system is solved on a coarse grid,then the linearized FE system is solved on the fine grid by Newton iteration based on the coarse solution.The fully discrete numerical approximation is analyzed,where the Galerkin finite element method for the space derivatives and the finite difference scheme for the time Caputo derivative with orderα∈(1,2)andα1∈(0,1).Numerical stability and optimal error estimate O(h^(r+1)+H^(2r+2)+τ^(min{3−α,2−α1}))in L^(2)-norm are presented for two-grid scheme,where t,H and h are the time step size,coarse grid mesh size and fine grid mesh size,respectively.Finally,numerical experiments are provided to confirm our theoretical results and effectiveness of the proposed algorithm.展开更多
Mevalonate metabolism plays an important role in regulating tumor growth and progression;however,its role in immune evasion and immune checkpoint modulation remains unclear.Here,we found that non-small cell lung cance...Mevalonate metabolism plays an important role in regulating tumor growth and progression;however,its role in immune evasion and immune checkpoint modulation remains unclear.Here,we found that non-small cell lung cancer(NSCLC)patients with higher plasma mevalonate response better to antiPD-(L)1 therapy,as indicated by prolonged progression-free survival and overall survival.Plasma mevalonate levels were positively correlated with programmed death ligand-1(PD-L1)expression in tumor tissues.In NSCLC cell lines and patient-derived cells,supplementation of mevalonate significantly upregulated the expression of PD-L1,whereas deprivation of mevalonate reduced PD-L1 expression.Mevalonate increased CD274 mRNA level but did not affect CD274 transcription.Further,we confirmed that mevalonate improved CD274 mRNA stability.Mevalonate promoted the affinity of the AU-rich elementbinding protein HuR to the 3'-UTR regions of CD274 mRNA and thereby stabilized CD274 mRNA.By in vivo study,we further confirmed that mevalonate addition enhanced the anti-tumor effect of anti-PD-L1,increased the infiltration of CD8^(+)T cells,and improved cytotoxic function of T cells.Collectively,our findings discovered plasma mevalonate levels positively correlated with the therapeutic efficacy of anti-PD-(L)1 antibody,and provided the evidence that mevalonate supplementation could be an immunosensitizer in NSCLC.展开更多
This paper aims to numerically study the generalized time-fractional Burgers equation in two spatial dimensions using the L1/LDG method. Here the L1 scheme is used to approximate the time-fractional derivative, i.e., ...This paper aims to numerically study the generalized time-fractional Burgers equation in two spatial dimensions using the L1/LDG method. Here the L1 scheme is used to approximate the time-fractional derivative, i.e., Caputo derivative, while the local discontinuous Galerkin (LDG) method is used to discretize the spatial derivative. If the solution has strong temporal regularity, i.e., its second derivative with respect to time being right continuous, then the L1 scheme on uniform meshes (uniform L1 scheme) is utilized. If the solution has weak temporal regularity, i.e., its first and/or second derivatives with respect to time blowing up at the starting time albeit the function itself being right continuous at the beginning time, then the L1 scheme on non-uniform meshes (non-uniform L1 scheme) is applied. Then both uniform L1/LDG and non-uniform L1/LDG schemes are constructed. They are both numerically stable and the \(L^2\) optimal error estimate for the velocity is obtained. Numerical examples support the theoretical analysis.展开更多
In this pape,~ we study uniform L1-stability and asymptotic completeness of the Vlasov-Yukawa-Boltzmann （V-Y-B） system. For a sufficiently small rand smooth initial data, we show that classical solutions exist globa...In this pape,~ we study uniform L1-stability and asymptotic completeness of the Vlasov-Yukawa-Boltzmann （V-Y-B） system. For a sufficiently small rand smooth initial data, we show that classical solutions exist globally and satisfy dispersion estimates, uniform L1-stability with respect to initial data and scattering type estimate. We show that the short range nature of interactions due to the Yukawa potential enables us to construct robust Lyapunov type functional to derive scattering states. In the zero mass limit of force carrier particles, we also show that the classical solutions to the V-Y-B system converge to that of the Vlasov-Poisson-Boltzmann （V-P-B） system in any finite time interval展开更多
In this paper,a nonlinear time-fractional coupled diffusion system is solved by using a mixed finite element(MFE)method in space combined with L1-approximation and implicit second-order backward difference scheme in t...In this paper,a nonlinear time-fractional coupled diffusion system is solved by using a mixed finite element(MFE)method in space combined with L1-approximation and implicit second-order backward difference scheme in time.The stability for nonlinear fully discrete finite element scheme is analyzed and a priori error estimates are derived.Finally,some numerical tests are shown to verify our theoretical analysis.展开更多
文摘Compressive sensing(CS)is an emerging methodology in computational signal processing that has recently attracted intensive research activities.At present,the basic CS theory includes recoverability and stability:the former quantifies the central fact that a sparse signal of length n can be exactly recovered from far fewer than n measurements via l1-minimization or other recovery techniques,while the latter specifies the stability of a recovery technique in the presence of measurement errors and inexact sparsity.So far,most analyses in CS rely heavily on the Restricted Isometry Property(RIP)for matrices.In this paper,we present an alternative,non-RIP analysis for CS via l1-minimization.Our purpose is three-fold:(a)to introduce an elementary and RIP-free treatment of the basic CS theory;(b)to extend the current recoverability and stability results so that prior knowledge can be utilized to enhance recovery via l1-minimization;and(c)to substantiate a property called uniform recoverability of l1-minimization;that is,for almost all random measurement matrices recoverability is asymptotically identical.With the aid of two classic results,the non-RIP approach enables us to quickly derive from scratch all basic results for the extended theory.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.6177322561773236,61873331,61803225in part by the Taishan Scholar Project of Shandong Province under Grant No.TSQN20161033。
文摘The issues of event-triggered exponential L1 filtering are studied for a class of networked linear switched systems.An event-triggered mechanism is proposed to enhance resource utilization in transmission,and save the communication cost of systems as well.Then,the filtering error system is reconstructed as a switched delay system with bounded disturbance through the input delay system approach.By resorting to the Lyapunov-Krasovskii functional approach and the average dwell time(ADT)technique,some interesting results are derived to guarantee the exponential stability with a prescribed L1 disturbance rejection level.Further,an event-triggered exponential L1 filter is designed via solving a set of feasible linear matrix inequalities(LMIs).Finally,the efficiency of the proposed results is verified through a numerical example and a PWM-driven boost converter circuit system.
基金This work is supported by the State Key Program of National Natural Science Foundation of China(11931003)National Natural Science Foundation of China(41974133,11971410)+2 种基金Project for Hunan National Applied Mathematics Center of Hunan Provincial Science and Technology Department(2020ZYT003)Hunan Provincial Innovation Foundation for Postgraduate,China(XDCX2020B082,XDCX2021B098)Postgraduate Scientific Research Innovation Project of Hunan Province(CX20210597).
文摘In this paper,we develop a two-grid method(TGM)based on the FEM for 2D nonlinear time fractional two-term mixed sub-diffusion and diffusion wave equations.A two-grid algorithm is proposed for solving the nonlinear system,which consists of two steps:a nonlinear FE system is solved on a coarse grid,then the linearized FE system is solved on the fine grid by Newton iteration based on the coarse solution.The fully discrete numerical approximation is analyzed,where the Galerkin finite element method for the space derivatives and the finite difference scheme for the time Caputo derivative with orderα∈(1,2)andα1∈(0,1).Numerical stability and optimal error estimate O(h^(r+1)+H^(2r+2)+τ^(min{3−α,2−α1}))in L^(2)-norm are presented for two-grid scheme,where t,H and h are the time step size,coarse grid mesh size and fine grid mesh size,respectively.Finally,numerical experiments are provided to confirm our theoretical results and effectiveness of the proposed algorithm.
基金supported by National Natural Science Foundation of China(No.81930102 to Bo Yang,No.82104196 to Xi Chen,No.82273949 to Ling Ding)Key R&D Program of Zhejiang(No.2022C03143 to Qinjie Weng,China)。
文摘Mevalonate metabolism plays an important role in regulating tumor growth and progression;however,its role in immune evasion and immune checkpoint modulation remains unclear.Here,we found that non-small cell lung cancer(NSCLC)patients with higher plasma mevalonate response better to antiPD-(L)1 therapy,as indicated by prolonged progression-free survival and overall survival.Plasma mevalonate levels were positively correlated with programmed death ligand-1(PD-L1)expression in tumor tissues.In NSCLC cell lines and patient-derived cells,supplementation of mevalonate significantly upregulated the expression of PD-L1,whereas deprivation of mevalonate reduced PD-L1 expression.Mevalonate increased CD274 mRNA level but did not affect CD274 transcription.Further,we confirmed that mevalonate improved CD274 mRNA stability.Mevalonate promoted the affinity of the AU-rich elementbinding protein HuR to the 3'-UTR regions of CD274 mRNA and thereby stabilized CD274 mRNA.By in vivo study,we further confirmed that mevalonate addition enhanced the anti-tumor effect of anti-PD-L1,increased the infiltration of CD8^(+)T cells,and improved cytotoxic function of T cells.Collectively,our findings discovered plasma mevalonate levels positively correlated with the therapeutic efficacy of anti-PD-(L)1 antibody,and provided the evidence that mevalonate supplementation could be an immunosensitizer in NSCLC.
基金the National Natural Science Foundation of China(Nos.11671251 and 12101266).
文摘This paper aims to numerically study the generalized time-fractional Burgers equation in two spatial dimensions using the L1/LDG method. Here the L1 scheme is used to approximate the time-fractional derivative, i.e., Caputo derivative, while the local discontinuous Galerkin (LDG) method is used to discretize the spatial derivative. If the solution has strong temporal regularity, i.e., its second derivative with respect to time being right continuous, then the L1 scheme on uniform meshes (uniform L1 scheme) is utilized. If the solution has weak temporal regularity, i.e., its first and/or second derivatives with respect to time blowing up at the starting time albeit the function itself being right continuous at the beginning time, then the L1 scheme on non-uniform meshes (non-uniform L1 scheme) is applied. Then both uniform L1/LDG and non-uniform L1/LDG schemes are constructed. They are both numerically stable and the \(L^2\) optimal error estimate for the velocity is obtained. Numerical examples support the theoretical analysis.
基金partially supported by a National Research Foundation of Korea Grant funded by the Korean Government(2014R1A2A205002096)supported by BK21 Plus-KAIST
文摘In this pape,~ we study uniform L1-stability and asymptotic completeness of the Vlasov-Yukawa-Boltzmann （V-Y-B） system. For a sufficiently small rand smooth initial data, we show that classical solutions exist globally and satisfy dispersion estimates, uniform L1-stability with respect to initial data and scattering type estimate. We show that the short range nature of interactions due to the Yukawa potential enables us to construct robust Lyapunov type functional to derive scattering states. In the zero mass limit of force carrier particles, we also show that the classical solutions to the V-Y-B system converge to that of the Vlasov-Poisson-Boltzmann （V-P-B） system in any finite time interval
基金the National Natural Science Fund(11661058,11301258,11361035)the Natural Science Fund of Inner Mongolia Autonomous Region(2016MS0102,2015MS0101)+1 种基金the Scientific Research Projection of Higher Schools of Inner Mongolia(NJZZ12011)the National Undergraduate Innovative Training Project(201510126026).
文摘In this paper,a nonlinear time-fractional coupled diffusion system is solved by using a mixed finite element(MFE)method in space combined with L1-approximation and implicit second-order backward difference scheme in time.The stability for nonlinear fully discrete finite element scheme is analyzed and a priori error estimates are derived.Finally,some numerical tests are shown to verify our theoretical analysis.
