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381.
Most papers dealing with partial orders assume that the input is given either in transitively closed or transitively reduced form. In this paper, we show that it is possible to solve some problems on partial orders in less time than it takes to perform transitive closure or reduction for general graphs. In particular, we present efficient algorithms for recognizing two dimensional partial orders and N-free partial orders when no assumptions are made about the form of the input.This work was supported by National Science Foundation Grant DCR-8604577 and the Vanderbilt University Research Council. 相似文献
382.
H.-C. Lai J.-C. Lee S.-C. Ho 《Journal of Mathematical Analysis and Applications》2006,323(2):1104-1115
In this paper we employ generalized convexity of complex functions to establish several sufficient optimality conditions for minimax programming in complex spaces. Using such criteria, we constitute a parametrical dual, and establish the weak, strong, and strict converse duality theorems in the framework. 相似文献
383.
Particle splitting methods are considered for the estimation of rare events. The probability of interest is that a Markov process first enters a set B before another set A, and it is assumed that this probability satisfies a large deviation scaling. A notion of subsolution is defined for the related calculus of variations problem, and two main results are proved under mild conditions. The first is that the number of particles generated by the algorithm grows subexponentially if and only if a certain scalar multiple of the importance function is a subsolution. The second is that, under the same condition, the variance of the algorithm is characterized (asymptotically) in terms of the subsolution. The design of asymptotically optimal schemes is discussed, and numerical examples are presented. 相似文献
384.
Patrick Clarysse 《Journal of Computational and Applied Mathematics》2010,234(4):1291-1302
This work is motivated by the necessity to improve heart image tracking. This technique is related to the ability of generating an apparent continuous motion, which is observable through the variation of intensity from a starting image to an ending one. Given two images ρ0 and ρ1, we calculate an evolution process ρ(t,⋅) which transports ρ0 to ρ1 by using the optimal extended optical flow. Such a strategy is found to be well suited for heart image tracking, provided the motion is controlled by a statistical model. In this paper we use viability theory to give sufficient conditions to handle the optimal extended optical flow subject to a point-wise statistical constraint by using Parzen’s approximation. The strategy is implemented in a 1D case and the numerical results which are presented show the efficiency of the proposed strategy. 相似文献
385.
Quantum families of maps between quantum spaces are defined and studied. We prove that quantum semigroup (and sometimes quantum group) structures arise naturally on such objects out of more fundamental properties. As particular cases we study quantum semigroups of maps preserving a fixed state and quantum commutants of given quantum families of maps. 相似文献
386.
A. Junker und G. Bergmann 《Fresenius' Journal of Analytical Chemistry》1976,278(3):191-198
Zusammenfassung Für die objektive Beurteilung und Auswahl von Meßpunkten aus überbestimmten spektrometrischen Vielkomponentensystemen werden als Bewertungskriterien die neuen Begriffe der Distension ¯85vj27l132g70k/xxlarge977.gif" alt="thetav" align="BASELINE" BORDER="0"> und der Systemdistension 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0"> = ¯85vj27l132g70k/xxlarge977.gif" alt="thetav" align="BASELINE" BORDER="0">i eingeführt. Beide geben ein quantitatives Maß der Selektivität einzelner Meßstellen in Relation zu den übrigen bzw. mit ihrem Mittelwert Aussagen über die Distension 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0"> eines Mehrkomponentensystems. Die Distension 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0"> erlaubt die optimale Reduzierung eines mehrfach überbestimmten Systems und somit auch die Auswahl optimaler Meßpunkte eines zunächst kontinuierlich vermessenen Systems. Rechenverfahren zur Bestimmung der Distension und der anschließenden Optimierung überbestimmter Systeme werden angegeben und an Beispielen erläutert.Ergänzt wird die 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0">-Optimierung durch eine 85vj27l132g70k/xxlarge8222.gif" alt="ldquor" align="MIDDLE" BORDER="0">längendiskriminierende85vj27l132g70k/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0"> Vorauswahl von geeigneten Meßpunkten aus kontinuierlichen Spektren durch Maximierung der Differenzspektren gegenüber den Summenspektren der übrigen Gemischkomponenten.Der Unterschied der 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0">-Optimierung zur Empfindlichkeitsoptimierung wird diskutiert.
Selection, comparison and valuation of optimum working conditions for quantitative multicomponent analysisII. Selection of optimum measuring points by means of the distension of the calibration matrix
Two new terms for the critical classification and selection of measuring points in spectrochemical multicomponent analysis are introduced: the distension 85vj27l132g70k/xxlarge977.gif" alt="thetav" align="BASELINE" BORDER="0"> and the distension of the system 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0"> = ¯85vj27l132g70k/xxlarge977.gif" alt="thetav" align="BASELINE" BORDER="0">i. Both terms give a quantitative relation of the selectivity of any single point of a spectrum with respect to the others and incorporate a measure of the overall-distension of a system. The distension allows the optimal reduction of a multiple overdetermined system and the optimal selection of the best points to be taken from a continuously measured spectrum. Procedures for the calculation of 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0"> and for the optimization which follows are given and demonstrated.The angle-dependent 85vj27l132g70k/xxlarge920.gif" alt="THgr" align="BASELINE" BORDER="0">-optimization is preceded by an 85vj27l132g70k/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">length-discriminating85vj27l132g70k/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0"> preselection of points of a continuously measured spectrum; this is done by comparing the difference spectra of all compounds with respect to the sum spectra.相似文献
387.
D. V. Vassilevich 《Letters in Mathematical Physics》1992,26(2):147-152
An algebraic technique of separation of gauge modes in Abelian gauge theories on homogeneous spaces is proposed. An effective potential for the Maxwell-Chern-Simons theory on S
3 is calculated. A generalization of the Chern-Simons action is suggested and analyzed with the example of SU(3)/U(1) X U(1). 相似文献
388.
The main result is to show that the space of nonmonotonic fuzzy measures on a measurable space (X,X) with total variation norm is separable if and only if the σ-algebra X is a finite set. Our result is related to fuzzy analysis, functional spaces and discrete mathematics. 相似文献
389.
The standard problem of radiation transfer in a bounded regionG 8543g13263t32/xxlarge8834.gif" alt="sub" align="MIDDLE" BORDER="0"> 8543g13263t32/xxlarge8477.gif" alt="Ropf" align="BASELINE" BORDER="0">
n
can be reformulated as a weakly singular integral equation with an unknown functionu: G8543g13263t32/xxlarge8594.gif" alt="rarr" align="BASELINE" BORDER="0">C(S
n–1) and a kernelK: ((G × G 8543g13263t32/xxlarge8726.gif" alt="setmn" align="MIDDLE" BORDER="0"> }x=y}, which is continuously differentiable with respect to the operator strong convergence topology. We take these observations into the basis of an abstract treatment of weakly singular integral equations with 8543g13263t32/xxlarge8466.gif" alt="Lscr" align="MIDDLE" BORDER="0">(E)-valued kernels, whereE is a Banach space. Our purpose is to characterize the smoothness of the solution by proving that it belongs to special weighted spaces of smooth functions. On the way, realizing the proof techniques, we establish the compactness of the integral operator or its square inL
p
(G,E),BC(G,E), and other spaces of interest in numerical analysis as well as in weighted spaces of smooth functions. The smoothness results are specified for the standard problem of radiation transfer as well as for the corresponding eigenvalue problem. 相似文献
390.
In this paper we consider two nonlinear elliptic problems driven by the p-Laplacian and having a nonsmooth potential (hemivariational inequalities). The first is an eigenvalue problem and we prove
that if the parameter λ < λ2 = the second eigenvalue of the p-Laplacian, then there exists a nontrivial smooth solution. The second problem is resonant both near zero and near infinity
for the principal eigenvalue of the p-Laplacian. For this problem we prove a multiplicity result. Our approach is variational based on the nonsmooth critical point
theory.
Second author is Corresponding author. 相似文献