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71.
Azriel Rosenfeld 《Fuzzy Sets and Systems》1984,13(3):241-246
In pattern recognition one often wants to measure geometric properties of imprecisely defined subsets of an image. This paper proposes definitions of intrinsic and extrinsic diameter for fuzzy subsets which reduce to the ordinary definitions when the subsets are crisp. We also define height and width for a fuzzy subset and show how they relate to the area (i.e., integral of membership). For convex fuzzy subsets the intrinsic diameter cannot exceed the extrinsic diameter, but it can be smaller. Finally, for piecewise constant convex fuzzy subsets the intrinsic diameter cannot exceed half the fuzzy perimeter, but this need not be true in the nonconvex case. 相似文献
72.
73.
In this paper we investigate spectral matrices, i.e., matrices with equal spectral and numerical radii. Various characterizations and properties of these matrices are given. 相似文献
74.
75.
Moshe Shaked 《Annals of the Institute of Statistical Mathematics》1979,31(1):67-84
In this work we consider some familiar and some new concepts of positive dependence for interchangeable bivariate distributions.
By characterizing distributions which are positively dependent according to some of these concepts, we indicate real situations
in which these concepts arise naturally. For the various families of positively dependent distributions we prove some closure
properties and demonstrate all the possible logical relations. Some inequalities are shown and applied to determine whether
under- (or over-) estimates, of various probabilistic quantities, occur when a positively dependent distribution is assumed
(falsely) to be the product of its marginals (that is, when two positively dependent random variables are assumed, falsely,
to be independent). Specific applications in reliability theory, statistical mechanics and reversible Markov processes are
discussed.
This work was partially supported by National Science Foundation GP-30707X1. It is part of the author's Ph.D. dissertation
prepared at the University of Rochester and supervised by A. W. Marshall.
Now at Indiana University. 相似文献
76.
77.
78.
As a whole new range of energies will be soon experimentally studied, we present predictions for hadronic cross sections at future very high energy accelerators. All calculations are based on results accumulated in reggeon field theory, where methods of field theory (in the continuum and on the lattice) and statistical mechanics have been used. We have employed these results and translated them into a manageable phenomenological analysis of existing FERMILAB-ISR data. The size of the non-leading terms is determined and enables us to predict cross sections at energies in the range of the near futurep¯p collider. Parameter-free scaling functions and critical exponents which are exactly calculable in RFT are thus brought to an experimental test. 相似文献
79.
80.
Tamam L Kraack H Sloutskin E Ocko BM Pershan PS Ulman A Deutsch M 《The journal of physical chemistry. B》2005,109(25):12534-12543
The molecular-scale structure and phase behavior of single-component Langmuir films of 4'-methyl-4-mercaptobiphenyl (MMB) and 4'-perfluoromethyl-4-mercaptobiphenyl (FMMB) on mercury were studied using surface tensiometry, grazing incidence X-ray diffraction, and X-ray reflectivity. At low coverages, a condensed but in-plane disordered single layer of surface-parallel molecules is found for both compounds. At high coverages, both compounds exhibit in-plane-ordered phases of standing-up molecules. For MMB, the biphenyl core dominates the structure, yielding a centered-rectangular unit cell with an area A(x) of 21.8 A(2)/molecule, with molecules tilted by approximately 14 degrees from the surface normal in the nearest-neighbor direction, and a coherence length xi of >1000 A for the crystalline domains. For FMMB, the perfluoromethyl group dominates the structure, yielding a hexagonal unit cell with untilted molecules, an area A(x) of 24.2 A(2)/molecule, and a much smaller xi of approximately 110 A. The structure is discussed in comparison with self-assembled monolayers of MMB on crystalline Au(111) and similar-length alkanethiolate SAMs on Au(111) and on mercury. The differences in the structure are discussed and traced to the differences in the substrate's surface structure, and in the molecular cross section and rigidity. 相似文献