The compactness criterion in l◇={x（·）∈l^∞（0,∞））｜lim t→∞ x（t）=x（∞）} is given and as an application,we study the existence of positive solutions of second order boundary value problems of differenc...The compactness criterion in l◇={x（·）∈l^∞（0,∞））｜lim t→∞ x（t）=x（∞）} is given and as an application,we study the existence of positive solutions of second order boundary value problems of difference equation on the half line by the fixedpoint theorem in cones.展开更多
This paper shows that first integrals of discrete equation of motion for Birkhoff systems can be determined explicitly by investigating the invariance properties of the discrete Pfaffian. The result obtained is a disc...This paper shows that first integrals of discrete equation of motion for Birkhoff systems can be determined explicitly by investigating the invariance properties of the discrete Pfaffian. The result obtained is a discrete analogue of theorem of Noether in the calculus of variations. An example is given to illustrate the application of the results.展开更多
Based on Krasnoselskii's fixed point theorem,matrix measure and functional analysis methods,some new sufficient conditions for the existence of periodic solutions of neutral functional differential equations with ...Based on Krasnoselskii's fixed point theorem,matrix measure and functional analysis methods,some new sufficient conditions for the existence of periodic solutions of neutral functional differential equations with distributed and discrete delays are obtained. Moreover,we construct an example to illustrate the feasibility of our results.展开更多
This paper takes further insight into the sparse geometry which offers a larger array aperture than uniform linear array(ULA)with the same number of physical sensors.An efficient method based on closed-form robust Chi...This paper takes further insight into the sparse geometry which offers a larger array aperture than uniform linear array(ULA)with the same number of physical sensors.An efficient method based on closed-form robust Chinese remainder theorem(CFRCRT)is presented to estimate the direction of arrival(DOA)from their wrapped phase with permissible errors.The proposed algorithm has significantly less computational complexity than the searching method while maintaining similar estimation precision.Furthermore,we combine all phase discrete Fourier transfer(APDFT)and the CFRCRT algorithm to achieve a considerably high DOA estimation precision.Both the theoretical analysis and simulation results demonstrate that the proposed algorithm has a higher estimation precision as well as lower computation complexity.展开更多
In this paper, an error is firstly pointed out in the proof of the main theorems (Theorem 4 and Theorem 6) in [1]. Then the error is corrected and the right proof is given.
Based on the results of the authors’ previous work "Discrete signal reconstruction from itsspectral magnitude and some samples," the uniqueness of the discrete signal reconstructionfrom its autocorrelation ...Based on the results of the authors’ previous work "Discrete signal reconstruction from itsspectral magnitude and some samples," the uniqueness of the discrete signal reconstructionfrom its autocorrelation function and one sample is discussed in detail in this paper, then fourtheorems are presented. And finally an effective iterative algorithm recovering the discretesignal is provided.展开更多
In this paper, we consider a discrete version of Aleksandrov＇s projection theorem. We prove that an origin-symmetric convex lattice set, whose lattice＇s y-coordinates＇ absolute values are not bigger than 2, can be ...In this paper, we consider a discrete version of Aleksandrov＇s projection theorem. We prove that an origin-symmetric convex lattice set, whose lattice＇s y-coordinates＇ absolute values are not bigger than 2, can be uniquely determined by its lattice projection counts if its cardinality is not 11. This partly answers a question on the discrete version of Aleksandrov＇s projection theorem which was proposed by Gardner, Gronchi and Zong in 2005.展开更多
基金The NSF(11626188,11671322)of ChinaGansu Provincial NSF(1606RJYA232)of China and NWNU-LKQN-15-16
文摘The compactness criterion in l◇={x（·）∈l^∞（0,∞））｜lim t→∞ x（t）=x（∞）} is given and as an application,we study the existence of positive solutions of second order boundary value problems of difference equation on the half line by the fixedpoint theorem in cones.
基金Project partially supported by the National Natural Science Foundation of China （Grant No 10172056） and the Science Research of the Education Bureau of Anhui Province, China （Grant No 2006KJ263B）. Acknowledgement We wish to thank the referees for their careful reading of the manuscript and their useful remarks which helped us to improve the quality of this paper.
文摘This paper shows that first integrals of discrete equation of motion for Birkhoff systems can be determined explicitly by investigating the invariance properties of the discrete Pfaffian. The result obtained is a discrete analogue of theorem of Noether in the calculus of variations. An example is given to illustrate the application of the results.
基金Supported by the National Natural Science Foundation of China(11071001)Supported by the NSF of Education Bureau of Anhui Province(KJ2009A005Z,KJ2010ZD02,2010SQRL159)+1 种基金Supported by the 211 Project of Anhui University(KJTD002B)Supported by the Natural Science Foundation of Anhui Province(1208085MA13)
文摘Based on Krasnoselskii's fixed point theorem,matrix measure and functional analysis methods,some new sufficient conditions for the existence of periodic solutions of neutral functional differential equations with distributed and discrete delays are obtained. Moreover,we construct an example to illustrate the feasibility of our results.
基金supported by the Fund for Foreign Scholars in University Research and Teaching Programs(the 111 Project)(B18039)
文摘This paper takes further insight into the sparse geometry which offers a larger array aperture than uniform linear array(ULA)with the same number of physical sensors.An efficient method based on closed-form robust Chinese remainder theorem(CFRCRT)is presented to estimate the direction of arrival(DOA)from their wrapped phase with permissible errors.The proposed algorithm has significantly less computational complexity than the searching method while maintaining similar estimation precision.Furthermore,we combine all phase discrete Fourier transfer(APDFT)and the CFRCRT algorithm to achieve a considerably high DOA estimation precision.Both the theoretical analysis and simulation results demonstrate that the proposed algorithm has a higher estimation precision as well as lower computation complexity.
基金Supported by the Natural Scientific Research Foundation of Yunnan Province(2000A0001-1M)the Scientific Foundations of Education Commisison of Yunnan Province(9911126)
文摘In this paper, an error is firstly pointed out in the proof of the main theorems (Theorem 4 and Theorem 6) in [1]. Then the error is corrected and the right proof is given.
文摘Based on the results of the authors’ previous work "Discrete signal reconstruction from itsspectral magnitude and some samples," the uniqueness of the discrete signal reconstructionfrom its autocorrelation function and one sample is discussed in detail in this paper, then fourtheorems are presented. And finally an effective iterative algorithm recovering the discretesignal is provided.
基金Supported by National 973 Project (Grant No.2011CB808003)National Natural Science Foundation ofChina (Grant No.11131001)
文摘In this paper, we consider a discrete version of Aleksandrov＇s projection theorem. We prove that an origin-symmetric convex lattice set, whose lattice＇s y-coordinates＇ absolute values are not bigger than 2, can be uniquely determined by its lattice projection counts if its cardinality is not 11. This partly answers a question on the discrete version of Aleksandrov＇s projection theorem which was proposed by Gardner, Gronchi and Zong in 2005.
