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81.
Questions of approximative nature are considered for a space of functions L
p(G, ), 1 p , defined on a locally compact abelian Hausdorff group G with Haar measure . The approximating subspaces which are analogs of the space of exponential type entire functions are introduced. 相似文献
82.
Roger C. Alperin 《Geometriae Dedicata》2002,92(1):105-113
We prove that polycyclic groups have uniform exponential or polynomial growth. 相似文献
83.
Robert M. Oliver 《Operations Research Letters》1984,3(3):111-117
Some new insights and results for exponential smoothing with application to forecasting and parameter estimation. Multidimensional exponential smoothing is described by a Kalman filter model with a limiting stationary gain matrix. 相似文献
84.
In this paper we introduce a concept of exponential dichotomy for linear skew-product semiflows (LSPS) in infinite dimensional Banach spaces, which is an extension of the classical concept of exponential dichotomy for time dependent linear differential equations in Banach spaces. We prove that the concept of exponential dichotomy used by Sacker-Sell and Magalhães in recent years is stronger than this one, but they are equivalent under suitable conditions. Using this concept we where able to find a formula for all the bounded negative continuations. After that, we characterize the stable and unstable subbundles in terms of the boundedness of the corresponding projector along (forward/backward) the LSPS and in terms of the exponential decay of the semiflow. The linear theory presented here provides a foundation for studying the nonlinear theory. Also, this concept can be used to study the existence of exponential dichotomy and the roughness property for LSPS.
85.
Sheldon M Ross 《Stochastic Processes and their Applications》1976,4(2):167-173
Consider an n-component reliability system having the property that at any time each of its components is either up (i.e., working) or down (i.e., being repaired). Each component acts independently and we suppose that each time the ith component goes up it remains up for an exponentially distributed time having mean μi, and each time it goes down it remains down for an exponentially distributed time having mean υi. We further suppose that whether or not the system itself is up at any time depends only on which components are up at that time. We are interested in the distribution of the time of first system failure when all components are initially up at time zero. In section 2 we show that this distribution has the NBU (i.e., new better than used) property, and in Section 3 we make use of this and other results to obtain a lower bound to the mean time until first system failure. 相似文献
86.
E. Olusegun George Govind S. Mudholkar 《Annals of the Institute of Statistical Mathematics》1981,33(1):125-129
Summary A functional form of the characteristic function of the sample median of three variates is shown to characterize the logistic
distribution. A consequence of this is a characterization of the logistic in terms of the Laplace distribution.
Research sponsored in part by the Air Force Office of Scientific Research, Air Force Systems Command, USAF under Grant No.
AFOSR-77-3360. The United States Govenment is authorized to reproduce and distribute reprints for governmental purposes notwith-standing
any copyright notation hereon. 相似文献
87.
88.
Connections between uniform exponential expansiveness and complete admissibility of the pair
are studied. A discrete version for a theorem due to Van Minh, Räbiger and Schnaubelt is presented. Equivalent characterizations of Perron type for uniform exponential expansiveness of evolution families in terms of complete admissibility are given. 相似文献
89.
Let
be a sequence of complex numbers such that
as
. For
close to the imaginary axis, upper bounds of the indicator of a nonzero entire function of exponential type with minimal growth vanishing on
is obtained. These bounds give sufficient conditions for the system of exponents
to be incomplete in an unbounded domain in
. 相似文献
90.
Weighted exponential polynomial approximation 总被引:7,自引:0,他引:7
邓冠铁 《中国科学A辑(英文版)》2003,46(2):280-287
A necessary and sufficient condition for completeness of systems of exponentials with a weight in Lp is established and a quantitative relation between the weight and the system of exponential in Lp is obtained by using a generalization of Malliavin's uniqueness theorem about Watson's problem. 相似文献