On the basis of a new WY -like representation block algorithms for orthogonal symplectic matrix factorizations are presented. Special emphasis is placed on symplectic QR and URV factorizations. The block variants mainly use level 3 (matrix-matrix) operations that permit data reuse in the higher levels of a memory hierarchy. Timing results show that our new algorithms outperform standard algorit...

This paper is a continuation of the work done to understand the security of a MOR cryptosystem over matrix groups defined over a finite field. In this paper we show that in the case of unitary group U(d, q) the security of the MOR cryptosystem is similar to the hardness of the discrete logarithm problem in Fq2d . In our way of developing the MOR cryptosystem, we developed row-column operations ...

Jacket matrices motivated by the center weight Hadamard matrices have played an important role in signal processing, communications, image compression, cryptography, etc. In this paper, we suggest a design approach for the Pauli block jacket matrix achieved by substituting some Pauli matrices for all elements of common matrices. Since, the well-known Pauli matrices have been widely utilized for...

Image hashing is a potential solution for image content authentication (a desired image hashing algorithm should be robust to common image processing operations and various geometric distortions). In the literature, researchers pay more attention to block-based image hashing algorithms due to their robustness to common image processing operations (such as lossy compression, low-pass filtering, ...

A configuration map is defined and computed, mapping all configurations of a part before an elementary manipulative operation to all possible outcomes. Configuration maps provide a basis for planning the operation sequences which occur in parts-feeder designs or in more general sensorless manipulation strategies for robots. Sequences of elementary operations are represented as matrix-products o...

In this paper, we give a weakly stable algorithm to solve a block Toeplitz system of linear equations. If the \look-ahead" steps taken to compute the parameters of the inversion formula for the block Toeplitz matrix are small compared to the order n of the matrix, the algorithm requires O(n 2) oating point operations. The parameters of the inversion formula are interpreted and computed in a rec...

This work attempts to give a uniied treatment of sensitivity issues in problems involving the application of-orthogonal transformations. Algorithms for such problems are sometimes implemented with minor variations in the way elementary hyperbolic transformations are used to construct a-orthogonal transformation. This results in a possible variation in the condition of the elementary transformat...

A configuration map is defined and computed, mapping all conflgumtions of a part before an elementary manipulative operation to all possible outcomes. Configuration maps provide abasis for planning the operation sequences which occur in parts-feeder designs or in more general sensorless manipulation strategies for robots. Sequences of elementary operations are represented as matrix-products of ...

The output of modern imaging techniques such as diffusion tensor MRI or the physical measurement of anisotropic behaviour in materials such as the stress-tensor consists of tensor-valued data. Hence adequate image processing methods for shape analysis, skeletonisation, denoising and segmentation are in demand. The goal of this paper is to extend the morphological operations of dilation, erosion...

The εi are called the elementary divisors of A and à is called the Smith normal form or elementary divisors form of A. In Section 3 we give an algorithm for computing for a given matrix A, its rank r and a prime p the p-parts of the elementary divisors of A. During the algorithm we perform row operations on the matrix A which are driven by only considering certain reductions of row vectors modu...