An efficient algorithm for the parametric resource allocation problem

The parametric resource allocation problem asks to minimize the sum of separable single-variable convex functions containing a parameter λ, Σ_{i = 1}ⁿ (ƒ_i(x_i + λg_i(x_i)), under simple constraints Σ_{i = 1}ⁿ x_i = M, l_i≤x_i≤u_i and x_i: nonnegative integers for i = 1, 2, …, n, where M is a given positive integer, and l_i and u_i are given lower and upper bounds on x_i. This paper presents an efficient algorithm for computing the sequence of all optimal solutions when λ is continuously changed from 0 to ∞. The required time is O(G√Mlog² n + n log n + n log(M/n)), where G = Σ_{i = 1}ⁿ u_i − Σ_{i = 1n} l_i and an evaluation of ƒ_i(·) or g_i(·) is assumed to be done in constant time.     

非负约束稀疏优化问题的一个等价性条件

加权l₁最小化是稀疏优化的主流方法之一。本文对带非负约束的l₀最小化问题与加权l₁最小化问题的解之间的关系进行了研究,给出了加权l₁最小化问题的约束矩阵和目标函数的系数是"s-权优"的定义,并通过该定义给出了加权l₁最小化问题的解是带非负约束的l₀最小化问题的解的条件。进一步,本文给出了"s-权优"的充分条件及其具体表示形式,并对其上下界进行了可计算的有效估计。     

非负约束稀疏优化问题的一个等价性条件

加权l₁最小化是稀疏优化的主流方法之一。本文对带非负约束的l₀最小化问题与加权l₁最小化问题的解之间的关系进行了研究,给出了加权l₁最小化问题的约束矩阵和目标函数的系数是"s-权优"的定义,并通过该定义给出了加权l₁最小化问题的解是带非负约束的l₀最小化问题的解的条件。进一步,本文给出了"s-权优"的充分条件及其具体表示形式,并对其上下界进行了可计算的有效估计。     

On the growth of components with non-fixed excesses

Denote by an l-component a connected graph with l edges more than vertices. We prove that the expected number of creations of (l+1)-component, by means of adding a new edge to an l-component in a randomly growing graph with n vertices, tends to 1 as l,n tends to ∞ but with l=o(n^1/4). We also show, under the same conditions on l and n, that the expected number of vertices that ever belong to an l-component is (12l)^1/3n^2/3.     

Actions that characterize I∞

It is well known that, if an identity operator on an n-dimensional Banach space V can be extended to any Banach space with the same norm, then V is isometric to l_∞⁽ⁿ⁾. We show that the identity is the only such operator.     

Structural Properties of Tensors and Complementarity Problems

In this paper, one of our main purposes is to prove the boundedness of the solution set of tensor complementarity problems such that the specific bounds depend only on the structural properties of such a tensor. To achieve this purpose, firstly, we prove that this class of structured tensors is strictly semi-positive. Subsequently, the strictly lower and upper bounds of operator norms are given for two positively homogeneous operators. Finally, with the help of the above upper bounds, we show that the solution set of tensor complementarity problems has the strictly lower bound. Furthermore, the upper bounds of spectral radius are obtained, which depends only on the principal diagonal entries of tensors.     

k-Lucas numbers and associated bipartite graphs

For a positive integer k2, the k-Fibonacci sequence {g_n^(k)} is defined as: g₁^(k)==g_k−2^(k)=0, g_k−1^(k)=g_k^(k)=1 and for n>k2, g_n^(k)=g_n−1^(k)+g_n−2^(k)++g_n−k^(k). Moreover, the k-Lucas sequence {l_n^(k)} is defined as l_n^(k)=g_n−1^(k)+g_n+k−1^(k) for n1. In this paper, we consider the relationship between g_n^(k) and l_n^(k) and 1-factors of a bipartite graph.     

q-distributions and Markov processes

We consider a sequence of integer-valued random variables X_n, n 1, representing a special Markov process with transition probability λ_{n, l}, satisfying P_{n, l} = (1 − λ_{n, l}) P_{n−1, l} + λ_{n, l−1} P_{n−1, l−1}. Whenever the transition probability is given by λ_{n, l} = q^{n + βl + γ} and λ_{n, l} = 1 − q^n+βl+γ, we can find closed forms for the distribution and the moments of the corresponding random variables, showing that they involve functions such as the q-binomial coefficients and the q-Stirling numbers. In general, it turns out that the q-notation, up to now mainly used in the theory of q-hypergeometrical series, represents a powerful tool to deal with these kinds of problems. In this context we speak therefore about q-distributions. Finally, we present some possible, mainly graph theoretical interpretations of these random variables for special choices of , β and γ.     

Reilly-type inequalities for p-Laplacian on compact Riemannian manifolds

For a compact Riemannian manifold M immersed into a higher dimensional manifold which can be chosen to be a Euclidean space, a unit sphere, or even a projective space, we successfully give several upper bounds in terms of the norm of the mean curvature vector of M for the first non-zero eigenvalue of the p-Laplacian (1<p<+∞) on M. This result can be seen as an extension of Reilly’s bound for the first non-zero closed eigenvalue of the Laplace operator.     

Some inequalities for commutators and an application to spectral variation. II

Inequalities that compare unitarily invariant norms of A - B and those of AΓ - ΓB and Γ^-1A - B Γ^-1 are obtained, where both A and B are either Hermitian or unitary or normal operators and Γ is a positive definite operator in a complex separable Hilbert space. These inequalities are then applied to derive bounds for spectral variation of diagonalisable matrices. Our new bounds improve substantially previously published bounds.     

Approximate computation of the permeability tensor of a periodic porous medium

The permeability tensor K of an infinite periodic porous medium, obtained using the homogenization theory, is considered. The solutions of an optimal control problem for the Dirichlet or Neumann equation are used to obtain optimal upper bounds for K. The test functions used for the estimations are simpler than those obtained by other authors. Some possibilities are given to obtain also lower bounds.     

Long-term analysis of degenerate parabolic equations in ℝ N

Longtime behavior of degenerate equations with the nonlinearity of polynomial growth of arbitrary order on the whole space R^N is considered. By using -trajectories methods, we proved that weak solutions generated by degenerate equations possess an (L_U² (R^N), L_loc² (R^N))-global attractor. Moreover, the upper bounds of the Kolmogorov ε-entropy for such global attractor are also obtained.     

一类奇异积分算子在加权空间的界的估计

设T是由Grubb和Moore引入的一类奇异积分算子,它的核满足一种新型利普希茨正则性.T^*是由T确定的极大奇异积分算子.本文通过建立与T和T^*相关的grand极大算子的弱型端点估计,得到了算子T和T^*在加权空间的由A_p权常数表示的界的估计和弱型端点估计.     

Two-sided bounds and perturbation results for regularized determinants of infinite order compact operators

A compact operator in a separable Hilbert space is of infinite order if it does not belong to any Schatten-von Neumann ideal. In the paper, upper and lower bounds for the regularized determinants of infinite order operators are derived. By these bounds, perturbations results for the regularized determinants are established.     

Infinite dimensional Ornstein–Uhlenbeck processes with unbounded diffusion – Approximation,quadratic variation,and Itô formula

The paper studies a class of Ornstein–Uhlenbeck processes on the classical Wiener space. These processes are associated with a diffusion type Dirichlet form whose corresponding diffusion operator is unbounded in the Cameron–Martin space. It is shown that the distributions of certain finite dimensional Ornstein–Uhlenbeck processes converge weakly to the distribution of such an infinite dimensional Ornstein–Uhlenbeck process. For the infinite dimensional processes, the ordinary scalar quadratic variation is calculated. Moreover, relative to the stochastic calculus via regularization, the scalar as well as the tensor quadratic variation are derived. A related Itô formula is presented.     

An existence theorem for generalized variational inequalities with discontinuous and pseudomonotone operators

This paper gives a solution existence theorem for a generalized variational inequality problem with an operator which is defined on an infinite dimensional space, which is C-pseudomonotone in the sense of Inoan and Kolumbán [D. Inoan, J. Kolumbán, On pseudomonotone set-valued mappings, Nonlinear Analysis 68 (2008) 47-53], but which may not be upper semicontinuous on finite dimensional subspaces. The proof of the theorem provides a new technique which reduces infinite variational inequality problems to finite ones. Two examples are given and analyzed to illustrate the theorem. Moreover, an example is presented to show that the C-pseudomonotonicity of the operator cannot be omitted in the theorem.     

Equivalent characterization of centralizers on <Emphasis Type="Italic">B</Emphasis>(<Emphasis Type="Italic">H</Emphasis>)

Let H be a Hilbert space with dim H≥2 and Z∈ß(H) be an arbitrary but fixed operator. In this paper we show that an additive map Φ:ß(H) → ß(H) satisfies Φ(AB)=Φ(A)B=AΦ(B) for any A,B∈ß(H) with AB=Z if and only if Φ(AB)=Φ(A)B=AΦ(B), ∀A, B∈ß(H), that is, Φ is a centralizer. Similar results are obtained for Hilbert space nest algebras. In addition, we show that Φ(A²)=AΦ(A)=Φ(A)A for any A∈ ß(H) with AA²=0 if and only if Φ(A)=AΦ(I)=Φ(I)A, ∀A∈ß(H), and generalize main results in Linear Algebra and its Application, 450, 243-249 (2014) to infinite dimensional case. New equivalent characterization of centralizers on ß(H) is obtained.     

Hausdorff operators on the Heisenberg group

This paper is devoted to the high-dimensional and multilinear Hausdorff operators on the Heisenberg group H n. The sharp bounds for the strong type(p, p)(1 ≤ p ≤∞) estimates of n-dimensional Hausdorff operators on H n are obtained. The sharp bounds for strong(p, p) estimates are further extended to multilinear cases. As an application, we derive the sharp constant for the multilinear Hardy operator on H n. The weak type(p, p)(1 ≤ p ≤∞) estimates are also obtained.     

Generic pairs of SU-rank 1 structures

For a supersimple SU-rank 1 theory T we introduce the notion of a generic elementary pair of models of T (generic T-pair). We show that the theory T^* of all generic T-pairs is complete and supersimple. In the strongly minimal case, T^* coincides with the theory of infinite dimensional pairs, which was used in (S. Buechler, Pseudoprojective strongly minimal sets are locally projective, J. Symbolic Logic 56(4) (1991) 1184–1194) to study the geometric properties of T. In our SU-rank 1 setting, we use T^* for the same purpose. In particular, we obtain a characterization of linearity for SU-rank 1 structures by giving several equivalent conditions on T^*, find a “weak” version of local modularity which is equivalent to linearity, show that linearity coincides with 1-basedness, and use the generic pairs to “recover” projective geometries over division rings from non-trivial linear SU-rank 1 structures.     

离散型p次Dirichlet型第一特征值

设μ=(μ_i)_i≥0为Z_+上的测度且p 1,考虑下述离散型p次Dirichlet型D_p(f)=Σ_(i=0)~∞μ_ib_i(f_i-f_(i+1))(f_i~(p-1)-f_(i+1)~(p-1)),f≥0,其中(b_i)_(i≥0)为Z_+上的正序列.本文旨在给出空间L~p(μ)上p次Dirichlet型D_p(f)所对应的第一特征值λ_(0,p)=inf{D_p(f):‖f‖_p=1,f非负且具有紧支撑}的上下界精细估计.