In this paper we concern the inverse problem of constructing the n-by-n real symmetric tridiagonal matrices C and K so that the monic quadratic pencil Q(λ) := λI + λC + K (where I is the identity matrix) possesses the given partial eigendata. We first provide the sufficient and necessary conditions for the existence of an exact solution to the inverse problem from the self-conjugate set of pres...

For a given partial solution, the partial inverse problem is to modify the coefficients such that there is a full solution containing the partial solution, while the full solution becomes optimal under new coefficients, and the total modification is minimum. In this paper, we show that the partial inverse assignment problem and the partial inverse minimum cut problem are NP-hard if there are bo...

A methodology to improve the stability robustness of feedback control systems designed using direct eigenspace assignment techniques is presented. The method consists of considering the sensitivity of the minimum singular value of the return difference transfer matrix at the plant input to small changes in the desired closed-loop eigenvalues and the specified elements of the desired closed-loop...

Motivated by considerations in quantum mechanics, we introduce the class of robust constraint satisfaction problems in which the question is whether every partial assignment of a certain length can be extended to a solution, provided the partial assignment does not violate any of the constraints of the given instance. We explore the complexity of specific robust colorability and robust satisfia...

in this paper, a fundamentally new method, based on the denition, is introduced for numerical computation of eigenvalues, generalized eigenvalues and quadratic eigenvalues of matrices. some examples are provided to show the accuracy and reliability of the proposed method. it is shown that the proposed method gives other sequences than that of existing methods but they still are convergent to t...

Topology control and channel assignment are key steps in the design of Wireless Mesh Networks (WMNs). Topology control consists of selecting a subset of communication links to set up the routing network, subject to certain degree constraints. Assigning non-overlapping frequency channels to the selected links in order to minimize the interference during communication is called the channel assign...

Background We consider planning tasks Π = 〈V ,O, s0, G,Cost〉 captured by the standard SAS formalism (Bäckström and Klein 1991; Bäckström and Nebel 1995) with operator costs, extended by conditional effects. In such a task, V is a set of finite-domain state variables, each with domain D(v). Each complete assignment to V is called a state, and S = ∏ v∈V D(v) is the state space of Π. The state s0 ...

In a WCDMA Node-B, orthogonal variable spreading factor (OVSF) codes are both valuable and limited. Many efforts are being made to create OVSF code-assignment schemes that support a maximum number of users. Here the author (a) proposes a batch arrival and partial loss queuing model to evaluate OVSF single-code assignment system performance, and (b) derives expressions for calculating two import...

Toeplitz matrices occur in many mathematical as well as scientific and engineering investigations. This paper considers the spectra of banded Toeplitz and quasi-Toeplitz matrices with emphasis on non-normal matrices of arbitrarily large order and relatively small bandwidth. These are the type of matrices that appear in the investigation of stability and convergence of difference approximations ...