In this paper, we consider multilevel relations in which security classiications are assigned at the gran-ularity of individual data elements. Usually these mul-tilevel relations exist only at the logical level. In reality , a multilevel relation is decomposed into a collection of single level base relations which are then physically stored in a database, and a recovery algorithm is used to rec...

In-house production or outsourcing are important strategic decisions for planning production and capacity in business organizations. Outsourcing to overseas suppliers is often associated with risk with respect to the quality of the products. Hence, we developed a multi-stage stochastic programming model that takes into account the uncertainty involved in the production of the quality of outsour...

In this paper we present two-level overlapping domain decomposition preconditioners for the finite-element discretisation of elliptic problems in two and three dimensions. The computational domain is partitioned into overlapping subdomains, and a coarse space correction is added. We present an algebraic way to define the coarse space, based on the concept of aggregation. This employs a (smoothe...

We propose a new variant of the two-stage recourse model. It can be used e.g., in managing resources in whose supply random interruptions may occur. Oil and natural gas are examples for such resources. Constraints in the resulting stochastic programming problems can be regarded as generalizations of integrated chance constraints. For the solution of such problems, we propose a new decomposition...

An efficient low-level word image representation plays a crucial role in general cursive word recognition. This paper proposes a novel representation scheme, where a word image can be represented as two sequences of feature vectors in two independent channels, which are extracted from vertical peak points on the upper external contour and at vertical minima on the lower external contour, respec...

Prime Component Decomposition of Images and its Applications in an Image Underst anding System Maciej Macieszczak, Ph-D. Concordia University, 1997 A reliable and flexible model of a low-level processing stage is one of the most crucial requirements in the development of an image understanding system (IUS). In this thesis, a model for the low-level processing stage based on a new scheme of prim...