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81.
Nested block designs and block designs properties such as orthogonality, orthogonal block structure and general balance are examined using the concept of a commutative quadratic subspace and standard properties of orthogonal projectors. In this geometrical context conditions for existence of the best linear unbiased estimators of treatment contrasts are also discussed.  相似文献   
82.
This paper develops a fast tabu search algorithm to minimize makespan in a flow shop problem with blocking. Some properties of the problem associated with the blocks of jobs have been presented and discussed. These properties allow us to propose a specific neighbourhood of algorithms. Also, the multimoves are used that consist in performing several moves simultaneously in a single iteration and guide the search process to more promising areas of the solutions space, where good solutions can be found. It allow us to accelerate the convergence of the algorithm. Besides, a dynamic tabu list is proposed that assists additionally to avoid being trapped at a local optimum. The proposed algorithms are empirically evaluated and found to be relatively more effective in finding better solutions than attained by the leading approaches in a much shorter time. The presented ideas can be applied in many local search procedures.  相似文献   
83.
The Cauchy distribution of the quotient of two random variables and its independence of the sum of squares of them together with some symmetry assumptions are the characteristic property of the bivariate elliptically contoured measures.  相似文献   
84.
Social Indicators Research - The European Union's regional policy aims to strengthen economic, social, and territorial cohesion and equal space development opportunities. It is an action...  相似文献   
85.
The classic N p-chart gives a signal if the number of successes in a sequence of independent binary variables exceeds a control limit. Motivated by engineering applications in industrial image processing and, to some extent, financial statistics, we study a simple modification of this chart, which uses only the most recent observations. Our aim is to construct a control chart for detecting a shift of an unknown size, allowing for an unknown distribution of the error terms. Simulation studies indicate that the proposed chart is superior in terms of out-of-control average run length, when one is interested in the detection of very small shifts. We provide a (functional) central limit theorem under a change-point model with local alternatives, which explains that unexpected and interesting behaviour. Since real observations are often not independent, the question arises whether these results still hold true for the dependent case. Indeed, our asymptotic results work under the fairly general condition that the observations form a martingale difference array. This enlarges the applicability of our results considerably, first, to a large class of time series models, and, second, to locally dependent image data, as we demonstrate by an example.  相似文献   
86.
The problem of optimal surface flattening in 3-D finds many applications in engineering and manufacturing. However, previous algorithms for this problem are all heuristics without any quality guarantee and the computational complexity of the problem was not well understood. In this paper, we prove that the optimal surface flattening problem is NP-hard. Further, we show that the problem of flattening a topologically spherical surface admits a PTAS and can be solved by a (1+ε)-approximation algorithm in O(nlog n) time for any constant ε>0, where n is the input size of the problem.  相似文献   
87.
88.
It is claimed that tax policy is neither time- nor space-independent due to cross-border tax base mobility, which induces spillovers. Specifically, fiscal shocks in one country are supposed to have an impact on fiscal policies in other countries. Different types of taxes influence economies differently. This paper addresses the question of their impact on government debt. Within a framework of spatial econometric modeling, we evaluate the impact of capital, labor and consumption taxes on public debt in 34 European countries in 2002–2011, and find strong spatial spillovers. We show that a consumption tax and, to a lesser degree, a capital tax significantly affect the sovereign debt, and that the global relations play a leading role (i.e. dominate the local ones) in shaping fiscal policy.  相似文献   
89.
This paper studies quantile estimation using Bernstein–Durrmeyer polynomials in terms of its mean squared error and integrated mean squared error including rates of convergence as well as its asymptotic distribution. Whereas the rates of convergence are achieved for i.i.d. samples, we also show that the consistency more or less directly follows from the consistency of the sample quantiles, such that our proposal can also be applied for risk measurement in finance and insurance. Furthermore, an improved estimator based on an error-correction approach is proposed for which a general consistency result is established. A crucial issue is how to select the degree of Bernstein–Durrmeyer polynomials. We propose a novel data-adaptive approach that controls the number of modes of the corresponding density estimator. Its consistency including an uniform error bound as well as its limiting distribution in the sense of a general invariance principle are established. The finite sample properties are investigated by a Monte Carlo study. Finally, the results are illustrated by an application to photovoltaic energy research.  相似文献   
90.
We propose a simple necessary and sufficient condition for existence of maximum likelihood estimators in a large class of canonical exponential families. We give an application to log-spline families.  相似文献   
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