共查询到20条相似文献,搜索用时 15 毫秒
1.
设M1和M2是两个带有预测量的线性模型,通过使用矩阵秩方法,本文给出了模型M1下预测量的最优线性无偏预测同时也是模型M2下的最优线性无偏预测的充分必要条件.作为这个结果的应用,我们给出了两个线性混合模型间最优线性无偏预测等价性的充分必要条件. 相似文献
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Asysmptotic Normality of the M-estimators for Parametric Components in Partly Linear ModelsShiPeide(施沛德);LiGuoying(李国英)(Insti... 相似文献
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Petri Nets (PNs) constitute a well known family of formalisms for the modelling and analysis of Discrete Event Dynamic Systems (DEDS). As general formalisms for DEDS, PNs suffer from the state explosion problem. A way to alleviate this difficulty is to relax the original discrete model and deal with a fully or partially continuous model. In Hybrid Petri Nets (HPNs), transitions can be either discrete or continuous, but not both. In Hybrid Adaptive Petri Nets (HAPNs), each transition commutes between discrete and continuous behaviour depending on a threshold: if its load is higher than its threshold, it behaves as continuous; otherwise, it behaves as discrete. This way, transitions adapt their behaviour dynamically to their load. This paper proposes a method to compute the Reachability Graph (RG) of HPNs and HAPNs. 相似文献
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The Mann iterations for nonexpansive mappings have only weak convergence even in a Hilbert space H. In order to overcome this weakness, Nakajo and Takahashi proposed the hybrid method for Mann’s iteration process:
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设两个样本数据不完全的线性模型,其中协变量的观测值不缺失,响应变量的观测值随机缺失。采用随机回归插补法对响应变量的缺失值进行补足,得到两个线性回归模型的完全样本数据,在一定条件下得到两响应变量分位数差异的对数经验似然比统计量的极限分布为加权x_1~2,并利用此结果构造分位数差异的经验似然置信区间。模拟结果表明在随机插补下得到的置信区间具有较高的覆盖精度。 相似文献
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Florence Merlevède Magda Peligrad Sergey Utev 《Journal of Theoretical Probability》1997,10(3):681-693
In this paper we study the behavior of sums of a linear process
associated to a strictly stationary sequence
with values in a real separable Hilbert space and
are linear operators from H to H. One of the results is that
satisfies the CLT provided
are i.i.d. centered having finite second moments and
. We shall provide an example which shows that the condition on the operators is essentially sharp. Extensions of this result are given for sequences of weak dependent random variables
under minimal conditions. 相似文献
8.
本文提出了线性模型中加权混合估计相对于最小二乘估计的两种相对效率,并给出了这些相对效率的上下界. 相似文献
9.
应用Monte Carlo EM(MCEM)算法给出了多层线性模型参数估计的新方法,解决了EM算法用于模型时积分计算困难的问题,并通过数值模拟将方法的估计结果与EM算法的进行比较,验证了方法的有效性和可行性. 相似文献
10.
考虑了响应变量随机缺失情形下的线性EV模型,通过利用逆概率加权的方法构造未知参数的经验对数似然比统计量,证明了所构造的经验对数似然比统计量渐近于X~2分布,利用这个结果可以构造未知参数的置信域 相似文献
11.
J.H. Carneiro de Araujo P.D. Gomes 《Journal of Computational and Applied Mathematics》2010,234(8):2562-3631
A three-field finite element scheme designed for solving systems of partial differential equations governing time-dependent viscoelastic flows is studied. Once a classical backward Euler time discretization is performed, the resulting three-field system of equations allows for a stable approximation of velocity, pressure and extra stress tensor, by means of continuous piecewise linear finite elements, in both two- and three- dimensional space. This is proved to hold for the linearized form of the system. An advantage of the new formulation is the fact that it provides an algorithm for the explicit iterative resolution of system nonlinearities. Convergence in an appropriate sense applying to these three flow fields is demonstrated. 相似文献
12.
本文根据《长江年鉴》提供的数据,分别利用灰色系统中的GM(1,1)模型和数值拟合模型,使用mat-lab软件,对长江水质污染问题进行了预测。给出了未来十年内,在不加治理的情况下,长江水质污染状况的数据,并对两种预测模型加以分析和比较。 相似文献
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We compare different approaches to the construction of the quantum mechanics of a particle in the general Riemannian space and space–time via quantization of motion along geodesic lines. We briefly review different quantization formalisms and the difficulties arising in their application to geodesic motion in a Riemannian configuration space. We then consider canonical, semiclassical (Pauli–De Witt), and Feynman (path-integral) formalisms in more detail and compare the quantum Hamiltonians of a particle arising in these models in the case of a static, topological elementary Riemannian configuration space. This allows selecting a unique ordering rule for the coordinate and momentum operators in the canonical formalism and a unique definition of the path integral that eliminates a part of the arbitrariness involved in the construction of the quantum mechanics of a particle in the Riemannian space. We also propose a geometric explanation of another main problem in quantization, the noninvariance of the quantum Hamiltonian and the path integral under configuration space diffeomorphisms. 相似文献
14.
J.-O. Lachaud 《Discrete Applied Mathematics》2011,159(18):2229-2250
The Minimum Length Polygon (MLP) is an interesting first order approximation of a digital contour. For instance, the convexity of the MLP is characteristic of the digital convexity of the shape, its perimeter is a good estimate of the perimeter of the digitized shape. We present here two novel equivalent definitions of MLP, one arithmetic, one combinatorial, and both definitions lead to two different linear time algorithms to compute them. This paper extends the work presented in Provençal and Lachaud (2009) [26], by detailing the algorithms and providing full proofs. It includes also a comparative experimental evaluation of both algorithms showing that the combinatorial algorithm is about 5 times faster than the other. We also checked the multigrid convergence of the length estimator based on the MLP. 相似文献
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Numerical solutions of Fredholm and Volterra integral equations of the second kind via hybrid functions, are proposed in this paper. Based upon some useful properties of hybrid functions, integration of the cross product, a special product matrix and a related coefficient matrix with optimal order, are applied to solve these integral equations. The main characteristic of this technique is to convert an integral equation into an algebraic; hence, the solution procedures are either reduced or simplified accordingly. The advantages of hybrid functions are that the values of n and m are adjustable as well as being able to yield more accurate numerical solutions than the piecewise constant orthogonal function, for the solutions of integral equations. We propose that the available optimal values of n and m can minimize the relative errors of the numerical solutions. The high accuracy and the wide applicability of the hybrid function approach will be demonstrated with numerical examples. The hybrid function method is superior to other piecewise constant orthogonal functions [W.F. Blyth, R.L. May, P. Widyaningsih, Volterra integral equations solved in Fredholm form using Walsh functions, Anziam J. 45 (E) (2004) C269–C282; M.H. Reihani, Z. Abadi, Rationalized Haar functions method for solving Fredholm and Volterra integral equations, J. Comp. Appl. Math. 200 (2007) 12–20] for these problems. 相似文献
17.
A gas network basically consists of a set of compressors and valves that are connected by pipes. The problem of gas network
optimization deals with the question of how to optimize the flow of the gas and to use the compressors cost-efficiently such
that all demands of the gas network are satisfied. This problem leads to a complex mixed integer nonlinear optimization problem.
We describe techniques for a piece-wise linear approximation of the nonlinearities in this model resulting in a large mixed
integer linear program. We study sub-polyhedra linking these piece-wise linear approximations and show that the number of
vertices is computationally tractable yielding exact separation algorithms. Suitable branching strategies complementing the
separation algorithms are also presented. Our computational results demonstrate the success of this approach.
Received: April, 2004 相似文献
18.
We give state space formulas for a (“central”) solution of the suboptimal Nehari problem for functions defined on the unit
disc and taking values in the space of bounded operators in separable Hilbert spaces. Instead of assuming exponential stability,
we assume a weaker stability concept (the combination of input-, output- and input-output stability), which allows us to solve
the problem for general H-infinity functions.
相似文献
19.
A new approach based on a global state space form is introduced for solving trajectory optimization problems with state inequality constraints via indirect methods. The use of minimal coordinates on a boundary arc of the state constraint eliminates severe problems, which occur for standard methods and are due to the appearance of differential-algebraic boundary-value problems. Together with a hybrid approach and a careful treatment of some interior-point conditions, we obtain an efficient and reliable solution method. 相似文献
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本文给出了超布朗运动的质量过程在不灭绝条件下的极限分布的拉普拉斯变换的具体形式,并得出了在较一般的分支特征下使其值空间从MF(Rd)扩张到MP(Rd)的一个充分条件. 相似文献