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1.
In Knowledge Discovery in Databases (KDD)/Data Mining literature, interestingness measures are used to rank rules according to the interest a particular rule is expected to evoke. In this paper, we introduce an aspect of subjective interestingness called item-relatedness. Relatedness is a consequence of relationships that exist between items in a domain. Association rules containing unrelated or weakly related items are interesting since the co-occurrence of such items is unexpected. Item-Relatedness helps in ranking association rules on the basis of one kind of subjective unexpectedness. We identify three types of item-relatedness – captured in the structure of a fuzzy taxonomy (an extension of the classical concept hierarchy tree). An item-relatedness measure for describing relatedness between two items is developed by combining these three types. Efficacy of this measure is illustrated with the help of a sample taxonomy. We discuss three mechanisms for extending this measure from a two-item set to an association rule consisting of a set of more than two items. These mechanisms utilize the relatedness of item-pairs and other aspects of an association rule, namely its structure, distribution of items and item-pairs. We compare our approach with another method from recent literature.  相似文献   

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Zusammenfassung In vorliegender Note wird ein Satz von Kato [7] über die Störung eines abgeschlossenen, normal auflösbaren OperatorsT mit endlichem Null-defekt (T) durch einen streng singulären Operator verallgemeinert. Zu diesem Zweck wird für jedes 0 mit Hilfe des Kuratowskischen Nichtkompaktheitsmaßes eine KlasseC von beschränkten, linearen Operatoren eingeführt, welche sowohl die streng singulären Operatoren als auch die OperatorenS mit S enthält.Das erzielte Resultat steht in engem Zusammenhang mit den Untersuchungen von Gol'denteinn, Gohberg und Markus [5] und von Gol'denteienn und Markus [6].  相似文献   

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Summary For differential operatorsM of second order (as defined in (1.1)) we describe a method to prove Range-Domain implications—Muu and an algorithm to construct these functions , , , . This method has been especially developed for application to non-inverse-positive differential operators. For example, for non-negativea 2 and for given functions = we require =C 0[0, 1] C 2([0, 1]–T) whereT is some finite set), (M) (t)(t), (t[0, 1]–T) and certain additional conditions for eachtT. Such Range-Domain implications can be used to obtain a numerical error estimation for the solution of a boundary value problemMu=r; further, we use them to guarantee the existence of a solution of nonlinear boundary value problems between the bounds- and .  相似文献   

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We consider depth first search (DFS for short) trees in a class of random digraphs: am-out model. Let i be thei th vertex encountered by DFS andL(i, m, n) be the height of i in the corresponding DFS tree. We show that ifi/n asn, then there exists a constanta(,m), to be defined later, such thatL(i, m, n)/n converges in probability toa(,m) asn. We also obtain results concerning the number of vertices and the number of leaves in a DFS tree.  相似文献   

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We study the linear system =Ax+Bu from a differential geometric point of view. It is well-known that controllability of the system is related to the one-parameter family of operators et B. We use this to give a proof of the classical controllability conditions in terms of the differential geometry of certain curves in n. We then view (t)=Im(et B) as a curve in appropriate Grassmannian and see that, in local coordinates, is an integral curve of the flow induced by a matrix Riccati equation. We obtain qualitative geometric conditions on that are equivalent to the controllability of the system. To get quantitiative results, we lift to a curve l' in a splitting space, a generalized Grassmannian, which has the advantage of being a reductive homogeneous space of the general linear group, GL(n). Explicit and simple expressions concerning the geometry of are computed in terms of the Lie algebra of GL(n), and these are related to the controllability of the system.James Wolper was a visiting professor in the Department of Mathematics at Texas Tech University while much of this research was conducted. He would like to express appreciation for the hospitality he received during his visit.  相似文献   

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In this note, we characterize the regular probability measures satisfying the Choquet-Deny convolution equation =* on Abelian topological semigroups for a given probability measure .  相似文献   

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LetA be a von Neumann algebra,J be the ideal of compact operators relative toA and letF + be the left-Fredholm class ofA. We call almost left-Fredholm the class = {A A: if P A is a projection and AP J then P J}. Then and the inclusion is proper unlessA is semifinite and has a non-large center. satisfies all of the algebraic properties ofF + but it is generally not open. IfA is semifinite then A iff there are central projectionsG with G = I such that AG F+(AG). Let :A A/J. Then the left almost essential spectrum ofA A, , coincides with the set of eigenvalues of (A)  相似文献   

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Summary Let denote the class of infinite product probability measures = 1× 2× defined on an infinite product of replications of a given measurable space (X, A), and let denote the subset of for which (A) =0 or 1 for each permutation invariant event A. Previous works by Hewitt and Savage, Horn and Schach, Blum and Pathak, and Sendler (referenced in the paper) discuss very restrictive sufficient conditions under which a given member , of belongs to . In the present paper, the class is shown to possess several closure properties. E.g., if and 0 n for some n 1, then 0× 1× 2×.... While the current results do not permit a complete characterization of they demonstrate conclusively that is a much larger subset of than previous results indicated. The interesting special case X={0,1} is discussed in detail.Research supported by the National Science Foundation under grant No. MCS75-07556  相似文献   

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The space D() associated with a positive measure on the unit circle is a Hilbert space made from the holomorphic functions in the unit disk whose derivatives are square integrable when weighted against the Poisson integral of . In this paper the structure of D() is investigated for the case where is a finite sum of atoms. The wandering vectors of the shift operator on D() are described.A portion of this work was done at the Mathematical Sciences Research Institute during the Holomorphic Spaces Program, in the fall of 1995. The author thanks MSRI for its support.  相似文献   

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We consider a conformally invariant regularization of an Abelian gauge theory in an Euclidean space of even dimension D 4 and regularized skeleton expansions for vertices and higher Green's functions. We set the respective regularized fields and with the scaling dimensions and into correspondence to the gauge field A and Euclidean current j . We postulate special rules for the limiting transition 0. These rules are different for the transversal and longitudinal components of the field and the current . We show that in the limit 0, there appear conformally invariant fields A and j each of which is transformed by a direct sum of two irreducible representations of the conformal group. Removing the regularization, we obtain a well-defined skeleton theory constructed from conformal two- and three-point correlation functions. We consider skeleton equations on the transversal component of the vertex operator and of the spinor propagator in conformal quantum electrodynamics. For simplicity, we restrict the consideration to an Abelian gauge field A , but generalization to a non-Abelian theory is straightforward.  相似文献   

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For a linear fourth order ordinary differential operator M we study Range Domain Implications (RDI). Let Co [O,1] be positive; we show under what conditions there exists a CO[O,1] such that the following RDI holds: Mu(x) (x) (0x1) u(x) (0x1). In particular we provide a numerical procedure to calculate .RDI are used to obtain error estimations and to solve related nonlinear problems.The basic idea to prove RDI is to split M into a product of second order differential operators which are easier to handle. For the general case that there exists no global splitting the concept of a local splitting is introduced.

The author would like to thank the European Research Office of the United States Army for their kind interest.  相似文献   

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— [0,1] ,E — - e=1 [0,1]. I — E =1, E=L 2 x e =xL 2 x E.

This work was prepared when the second author was a visiting professor of the CNR at the University of Firenze. He was supported by the Soros International Fund.  相似文献   

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[10], 1 . [4] K q-, , 1p2 pp K q, q=p/p–1)(q=+, p=1 K = ). — p ⊃<<. , , , , K . , ( ) , q .  相似文献   

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Summary We study integral functionals of the formF(u, )= f(u)dx, defined foru C1(;R k), R n . The functionf is assumed to be polyconvex and to satisfy the inequalityf(A) c0¦(A)¦ for a suitable constant c0 > 0, where (A) is then-vector whose components are the determinants of all minors of thek×n matrixA. We prove thatF is lower semicontinuous onC 1(;R k) with respect to the strong topology ofL 1(;R k). Then we consider the relaxed functional , defined as the greatest lower semicontinuous functional onL 1(;R k ) which is less than or equal toF on C1(;R k). For everyu BV(;R k) we prove that (u,) f(u)dx+c0¦Dsu¦(), whereDu=u dx+Dsu is the Lebesgue decomposition of the Radon measureDu. Moreover, under suitable growth conditions onf, we show that (u,)= f(u)dx for everyu W1,p(;R k), withp min{n,k}. We prove also that the functional (u, ) can not be represented by an inte- gral for an arbitrary functionu BVloc(R n;R k). In fact, two examples show that, in general, the set function (u, ) is not subadditive whenu BVloc(R n;R k), even ifu W loc 1,p (R n;R k) for everyp < min{n,k}. Finally, we examine in detail the properties of the functionsu BV(;R k) such that (u, )= f(u)dx, particularly in the model casef(A)=¦(A)¦.  相似文献   

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The proximity is investigated of the solution of Cauchy's problem for the equation u t +((u))x= u xx ((u) > 0) to the solution of Cauchy's problem for the equation ut+ ((u))x= 0, when the solution of the latter problem has a finite number of lines of discontinuity in the strip 0 t T. It is proved that, everywhere outside a fixed neighborhood of the lines of discontinuity, we have |u–u| C, where the constant C is independent of. Similar inequalities are derived for the first derivatives of u–u.Translated from Matematicheskie Zametki, Vol. 8, No. 3, pp. 309–320, September, 1970.In conclusion we express our gratitude to L. A. Chudov for his valuable advice concerning this work.  相似文献   

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