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101.
102.
In this paper, we give some equivalent conditions on a Banach frame for a Banach space by using the pseudoinverse operator. We also consider the stability of a Banach frame for a Banach space X with respect to Xd or an Xd-frame for a Banach space X under perturbation. These results generalize and improve the related works of Balan, Casazza, Christensen, Stoeva and Jian et al.  相似文献   
103.
The angular momentum of the Earth produces gravitomagnetic components of the Riemann curvature tensor, which are of the order of 10−10 of the Newtonian terms arising from the mass of the Earth. Due to the dragging of the local inertial frame by the spinning Earth, there are also secular terms, which grow in time. These fields can be detected in principle by a set of orbiting superconducting gravity gradiometers. The Riemann tensor components for various spacecraft orientations have been computed and the principle of detecting the gravitomagnetic tidal force has been published. In this paper, we review the conclusions of the earlier analyses and discuss the feasibility of the gravity gradiometer experiment.  相似文献   
104.
In this paper, we study Smarandache curves in the 4-dimensional Galilean space G4. We obtain Frenet-Serret invariants for the Smarandache curve in G4. The first, second and third curvature of Smarandache curve are calculated. These values depending upon the first, second and third curvature of the given curve. Examples will be illustrated.  相似文献   
105.
Wavelet frames have gained considerable popularity during the past decade,primarily due to their substantiated applications in diverse and widespread fields of science and engineering.Finding general and verifiable conditions which imply that the wavelet systems are wavelet frames is among the core problems in time-frequency analysis.In this article,we establish some new inequalities for wavelet frames on local fields of positive characteristic by means of the Fourier transform.As an application,an improved version of the Li-Jiang inequality for wavelet frames on local fields is obtained.  相似文献   
106.
The purpose of this paper is to discuss representations of high order C0finite element spaces on simplicial meshes in any dimension.When computing with high order piecewise polynomials the conditioning of the basis is likely to be important.The main result of this paper is a construction of representations by frames such that the associated L2condition number is bounded independently of the polynomial degree.To our knowledge,such a representation has not been presented earlier.The main tools we will use for the construction is the bubble transform,introduced previously in[1],and properties of Jacobi polynomials on simplexes in higher dimensions.We also include a brief discussion of preconditioned iterative methods for the finite element systems in the setting of representations by frames.  相似文献   
107.
谢琳  宋玉靖 《数学学报》2000,43(2):213-220
本文利用引入的KS性质,刻划了那些其Scott拓扑可由开滤子生成的分配备格,该结果也是对[1]中一公开问题的一种解答.本文的刻划定理对于判定分配备格的Scott拓扑是否与Scott开滤子拓扑一致具有较强的可操作性,应用该刻划定理给出大量非连续格,其Scott拓扑具有开滤子基.  相似文献   
108.
在分配格中引入了次极大滤子的概念,并以此给出了分配格的滤子格是空间式frame的一种新证明,然后研究了次极大滤子在Heyting代数中的一些具体性质。  相似文献   
109.
积分时间可调的CCD相机驱动时序设计与实现   总被引:2,自引:1,他引:1  
周建康  陈新华  周望  沈为民 《光子学报》2008,37(11):2300-2304
在分析帧转移CCD的结构和驱动时序的基础之上,对时序关系和积分时间选择进行了计算,并给出积分时间可调的循环嵌套时序设计方案.以现场可编程逻辑门阵列为硬件载体,用硬件描述语言对方案进行设计.考虑到CCD驱动时序复杂、相位要求严格,提出运用锁相环技术进行高频信号的精确移相,用嵌入式逻辑分析仪对时序进行采样验证,在CCD电路板上实现了积分时间可调的CCD空间相机驱动时序.  相似文献   
110.
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