共查询到20条相似文献,搜索用时 31 毫秒
1.
A (v, β o , μ)-design over regular graph G = (V, E) of degree d is an ordered pair D = (V, B), where |V| = v and B is the set of maximum independent sets of G called blocks such that if i, j ∈ V, i ≠ j and if i and j are not adjacent in G then there are exactly μ blocks containing i and j. In this paper, we study (v, β o , μ)-designs over the graphs K n × K n , T(n)-triangular graphs, L 2(n)-square lattice graphs, Petersen graph, Shrikhande graph, Clebsch graph and the Schläfli graph and non-existence of (v, β o , μ)-designs over the three Chang graphs T 1(8), T 2(8) and T 3(8). 相似文献
2.
The aim of this paper is two-fold. Given a recollement (T′, T, T″, i*, i*, i!, j!, j*, j*), where T′, T, T″ are triangulated categories with small coproducts and T is compactly generated. First, the authors show that the BBD-induction of compactly generated t-structures is compactly generated when i* preserves compact objects. As a con-sequence, given a ladder (T′, T, T″, T, T′) of height 2, then the certain BBD-induction of compactly generated t-structures is compactly generated. The authors apply them to the recollements induced by homological ring epimorphisms. This is the first part of their work. Given a recollement (D(B-Mod),D(A-Mod),D(C-Mod), i*, i*, i!, j!, j*, j*) induced by a homological ring epimorphism, the last aim of this work is to show that if A is Gorenstein, A B has finite projective dimension and j! restricts to D b (C-mod), then this recollement induces an unbounded ladder (B-Gproj,A-Gproj, C-Gproj) of stable categories of finitely generated Gorenstein-projective modules. Some examples are described. 相似文献
3.
S. A. Gritsenko 《Proceedings of the Steklov Institute of Mathematics》2017,296(1):65-87
Let N 0(T) be the number of zeros of the Davenport–Heilbronn function in the interval [1/2, 1/2+ i T]. It is proved that N 0(T) ? T (ln T)1/2+1/16?ε, where ε is an arbitrarily small positive number. 相似文献
4.
Several methods exist for solving the interval linear programming (ILP) problem. In most of these methods, we can only obtain the optimal value of the objective function of the ILP problem. In this paper we determine the optimal solution set of the ILP as the intersection of some regions, by the best and the worst case (BWC) methods, when the feasible solution components of the best problem are positive. First, we convert the ILP problem to the convex combination problem by coefficients 0 ≤ λ j , μ ij , μ i ≤ 1, for i = 1, 2, . . . , m and j = 1, 2, . . . , n. If for each i, j, μ ij = μ i = λ j = 0, then the best problem has been obtained (in case of minimization problem). We move from the best problem towards the worst problem by tiny variations of λ j , μ ij and μ i from 0 to 1. Then we solve each of the obtained problems. All of the optimal solutions form a region that we call the optimal solution set of the ILP. Our aim is to determine this optimal solution set by the best and the worst problem constraints. We show that some theorems to validity of this optimal solution set. 相似文献
5.
S. S. Gabriyelyan 《Journal of Theoretical Probability》2011,24(3):595-614
Let μ and ν be fixed probability measures on a filtered space \((\varOmega, \mathcal{F}, \allowbreak(\mathcal{F}_{t} )_{t\in \mathbf{R}^{+} } )\). Denote by μ T and ν T (respectively, μ T? and ν T?) the restrictions of the measures μ and ν on \(\mathcal{F}_{T} \) (respectively, on \(\mathcal{F}_{T-} \)) for a stopping time T. We find the Hahn decomposition of μ T and ν T using the Hahn decomposition of the measures μ, ν and the Hellinger process h t in the strict sense of order \(\frac{1}{2}\). The norm of the absolutely continuous component of μ T? with respect to ν T? is computed in terms of density processes and Hellinger integrals. 相似文献
6.
G. K. Agrafiotis M. Z. Tsoukalas 《The Journal of the Operational Research Society》1995,46(10):1269-1280
In this paper a class of correlated cumulative processes, B s (t) = ∑N(t)i=1 H s (X i )X i , is studied with excess level increments X i ?s, where {N(t), t ?0} is the counting process generated by the renewal sequence T n , T n and X n are correlated for given n, H s (t) is the Heaviside function and s?0 is a given constant. Several useful results, for the distributions of B s (t), and that of the number of excess (non-excess) increments on (0, t) and the corresponding means, are derived. First passage time problems are also discussed and various asymptotic properties of the processes are obtained. Transform results, by applying a flexible form for the joint distribution of correlated pairs (T n , X n ) are derived and inverted. The case of non-excess level increments, X i < s, is also considered. Finally, applications to known stochastic shock and pro-rata warranty models are given. 相似文献
7.
Results on extrapolation withA∞ weights in grand Lebesgue spaces are obtained. Generally, these spaces are defined with respect to the productmeasure μ1 ×· · ·×μn onX1 ×· · ·×Xn, where (Xi, di, μi), i = 1,..., n, are spaces of homogeneous type. As applications of the obtained results, new one-weight estimates with A∞ weights for operators of harmonic analysis are derived. 相似文献
8.
P. A. Sipailo 《Differential Equations》2018,54(5):696-707
For an embedding i : X ? M of smooth manifolds and a Fourier integral operator Φ on M defined as the quantization of a canonical transformation g: T*M \ {0} → T*M \ {0}, we consider the operator i*Φi* on the submanifold X, where i* and i* are the boundary and coboundary operators corresponding to the embedding i. We present conditions on the transformation g under which such an operator has the form of a Fourier integral operator associated with the fiber of the cotangent bundle over a point. We obtain an explicit formula for calculating the amplitude of this operator in local coordinates. 相似文献
9.
The material presented is based on a numerical investigation that was made for five types of probability approximations which involve the first seven terms of the Edgeworth series expansion for the distribution of a continuous random variableT. For each approximation, the probability expressions considered in the investigation were Pr(T≦t), Pr(?t≦T≦t) and Pr(?t+1≦T≦t), whereT has zero mean, unit variance, and specified central momentsμ 3,μ 4,μ 5. Computations were made for thoset values in the set ?4.00(0.25) 4.00 that are pertinent for the probability expression being considered and for all combinations of the following values forμ 3,μ 4,μ 5∶μ 3=?2.0, ?1.0, ?0.5,0.0, 0.5, 1.0, 2.0;μ 4=1, 2, 3, 5, 10;μ 5=0.0, 3μ 3?6.0, 3μ 3, 3μ 3+6.0. The principal results of this paper consist of a specification (for each approximation, probability expression, andμ 3,μ 4,μ 5 combination) of limits ont such that within these limits the computed values of the probability expression are meaningful; that is, satisfy required monotonicity properties as a function oft and are neither negative nor greater than unity. Also the values of Pr(T≦0) and of Pr(?1.75≦T≦1.75) are listed for the cases considered. These results indicate that the types of approximations investigated are of doubtful usefulness for the situations examined; that is, for cases where the third and higher order moments of the random variable considered differ substantially from those for the normal variable having the same mean and variance. 相似文献
10.
Qin and Lawless (1994) established the statistical inference theory for the empirical likelihood of the general estimating equations. However, in many practical problems, some unknown functional parts h(t) appear in the corresponding estimating equations EFG(X, h(T), β) = 0. In this paper, the empirical likelihood inference of combining information about unknown parameters and distribution function through the semiparametric estimating equations are developed, and the corresponding Wilk’s theorem is established. The simulations of several useful models are conducted to compare the finite-sample performance of the proposed method and that of the normal approximation based method. An illustrated real example is also presented. 相似文献
11.
Minghui Zhao 《Algebras and Representation Theory》2017,20(4):923-950
Let U be the quantum group and f be the Lusztig’s algebra associated with a symmetrizable generalized Cartan matrix. The algebra f can be viewed as the positive part of U. Lusztig introduced some symmetries T i on U for all i ∈ I. Since T i (f) is not contained in f, Lusztig considered two subalgebras i f and i f of f for any i ∈ I, where i f={x ∈ f | T i (x) ∈ f} and \({^{i}\mathbf {f}}=\{x\in \mathbf {f}\,\,|\,\,T^{-1}_{i}(x)\in \mathbf {f}\}\). The restriction of T i on i f is also denoted by \(T_{i}:{_{i}\mathbf {f}}\rightarrow {^{i}\mathbf {f}}\). The geometric realization of f and its canonical basis are introduced by Lusztig via some semisimple complexes on the variety consisting of representations of the corresponding quiver. When the generalized Cartan matrix is symmetric, Xiao and Zhao gave geometric realizations of Lusztig’s symmetries in the sense of Lusztig. In this paper, we shall generalize this result and give geometric realizations of i f, i f and \(T_{i}:{_{i}\mathbf {f}}\rightarrow {^{i}\mathbf {f}}\) by using the language ’quiver with automorphism’ introduced by Lusztig. 相似文献
12.
In 1982 Thomassen asked whether there exists an integer f(k,t) such that every strongly f(k,t)-connected tournament T admits a partition of its vertex set into t vertex classes V 1,…V t such that for all i the subtournament T[V i] induced on T by V i is strongly k-connected. Our main result implies an affirmative answer to this question. In particular we show that f(k, t)=O(k 7 t 4) suffices. As another application of our main result we give an affirmative answer to a question of Song as to whether, for any integer t, there exists aninteger h(t) such that every strongly h(t)-connected tournament has a 1-factor consisting of t vertex-disjoint cycles of prescribed lengths. We show that h(t)=O(t 5) suffices. 相似文献
13.
We obtain bivariate forms of Gumbel’s, Fréchet’s and Chung’s linear inequalities for P(S ≥ u, T ≥ v) in terms of the bivariate binomial moments {S i, j }, 1 ≤ i ≤ k,1 ≤ j ≤ l of the joint distribution of (S, T). At u = v = 1, the Gumbel and Fréchet bounds improve monotonically with non-decreasing (k, l). The method of proof uses combinatorial identities, and reveals a multiplicative structure before taking expectation over sample points. 相似文献
14.
J. Sztrik 《The Journal of the Operational Research Society》1988,39(2):201-207
This article treats a version of the multiple machine-interference problem with r operatives under FIFO repair discipline. The running times of machine i are supposed to be identically and arbitrarily distributed random variables with density function f i (x), i = 1,…, n. The repair times of all machines are assumed to be identically and exponentially distributed random variables with mean 1/μ. The paper provides the main steady-state operational characteristics of the system when the running and repair speeds are dependent on the number of machines in working order. 相似文献
15.
Yu. Golubev 《Mathematical Methods of Statistics》2018,27(3):205-225
The paper considers a simple Errors-in-Variables (EiV) model Yi = a + bXi + εξi; Zi= Xi + σζi, where ξi, ζi are i.i.d. standard Gaussian random variables, Xi ∈ ? are unknown non-random regressors, and ε, σ are known noise levels. The goal is to estimates unknown parameters a, b ∈ ? based on the observations {Yi, Zi, i = 1, …, n}. It is well known [3] that the maximum likelihood estimates of these parameters have unbounded moments. In order to construct estimates with good statistical properties, we study EiV model in the large noise regime assuming that n → ∞, but \({\epsilon ^2} = \sqrt n \epsilon _ \circ ^2,{\sigma ^2} = \sqrt n \sigma _ \circ ^2\) with some \(\epsilon_\circ^2, \sigma_\circ^2>0\). Under these assumptions, a minimax approach to estimating a, b is developed. It is shown that minimax estimates are solutions to a convex optimization problem and a fast algorithm for solving it is proposed. 相似文献
16.
Aladár Heppes 《Discrete and Computational Geometry》2011,45(2):321-328
Let K denote an oval, a centrally symmetric compact convex domain with non-empty interior. A family of translates of K is said to have property T(k) if for every subset of at most k translates there exists a common line transversal intersecting all of them. Property T means that a transversal exists for all members of the family. Two translates, K i and K j are said to be φ-disjoint, φ>0, if the concentric φ-enlarged copies of K i and K j are disjoint. It is well known that in a φ-disjoint family of congruent discs T(3)?T if \(\varphi>\sqrt{2}\), and \(T(3)\not\Rightarrow T\) if \(\varphi<\sqrt{2}\). In this note finite φ-disjoint T(3)-families of translates of an oval will be investigated. 相似文献
17.
The generalized k-connectivity κ k (G) of a graph G was introduced by Chartrand et al. in 1984. As a natural counterpart of this concept, Li et al. in 2011 introduced the concept of generalized k-edge-connectivity which is defined as λ k (G) = min{λ(S): S ? V (G) and |S| = k}, where λ(S) denotes the maximum number l of pairwise edge-disjoint trees T 1, T 2, …, T l in G such that S ? V (T i ) for 1 ? i ? l. In this paper we prove that for any two connected graphs G and H we have λ 3(G □ H) ? λ 3(G) + λ 3(H), where G □ H is the Cartesian product of G and H. Moreover, the bound is sharp. We also obtain the precise values for the generalized 3-edge-connectivity of the Cartesian product of some special graph classes. 相似文献
18.
M. M. Malamud H. Neidhardt V. V. Peller 《Functional Analysis and Its Applications》2017,51(3):185-203
In this paper we prove that for an arbitrary pair {T 1, T 0} of contractions on Hilbert space with trace class difference, there exists a function ξ in L 1(T) (called a spectral shift function for the pair {T 1, T 0}) such that the trace formula trace(f(T 1) ? f(T 0)) = ∫T f′(ζ)ξ(ζ)dζ holds for an arbitrary operator Lipschitz function f analytic in the unit disk. 相似文献
19.
Clifford Smyth 《Order》2018,35(2):393-402
We present a probabilistic characterization of the dominance order on partitions. Let ν be a partition and Y ν its Ferrers diagram, i.e. a stack of rows of cells with row i containing ν i cells. Let the cells of Y ν be filled with independent and identically distributed draws from the random variable X = B i n(r, p) with r ≥ 1 and p ∈ (0, 1). Given j, t ≥ 0, let P(ν, j, t) be the probability that the sum of all the entries in Y ν is j while the sum of the entries in each row of Y ν is no more than t. It is shown that if ν and μ are two partitions of n, ν dominates μ if and only if P(ν, j, t) ≤ P(μ, j, t) for all j, t ≥ 0. It is shown that the same result holds if X is any log-concave integer valued random variable with {i : P(X = i) > 0} = {0, 1,…,r} for some r ≥ 1. 相似文献
20.
N. Yu. Makarenko 《Siberian Mathematical Journal》2007,48(1):95-111
We prove that if a (?/n?)-graded Lie algebra L = ? i=0 n?1 L i has d nontrivial components L i and the null component L 0 has finite dimension m, then L has a homogeneous solvable ideal of derived length bounded by a function of d and of codimension bounded by a function of m and d. An analogous result holds also for the (?/n?)-graded Lie rings L = ? i=0 n?1 with few nontrivial components L i if the null component L 0 has finite order m. These results generalize Kreknin’s theorem on the solvability of the (?/n?)-graded Lie rings L = ? i=0 n?1 L i with trivial component L 0 and Shalev’s theorem on the solvability of such Lie rings with few nontrivial components L i . The proof is based on the method of generalized centralizers which was created by E. I. Khukhro for Lie rings and nilpotent groups with almost regular automorphisms of prime order [1], as well as on the technique developed in the work of N. Yu. Makarenko and E. I. Khukhro on the almost solvability of Lie algebras with an almost regular automorphism of finite order [2]. 相似文献