Since the requirement of data warehouse is increasing, it is necessary to develop eflcient mechanisms for data warehouses incorporating various kinds of database systems. Essentially, materialized views are used for data warehouses and various methods for relational databases have been developed. In this paper, we will first discuss a method to realize materialized views for object-on’ented dat...

In this paper we present a complete description of ideal projectors from the space of bivariate polynomials F[x, y] onto its subspace F<n[x, y] of polynomials of degree less than n. Several applications are given. In particular, we study small perturbations of ideal projectors as well as the limits of Lagrange projectors. The latter results verify one particular case of a conjecture of Carl de ...

Physical systems are often naturally formulated as descriptor systems (DSs) which form a superset of the more restrictive standard state spaces. The analysis of a DS, however, is complicated by the algebraic coupling between its proper and improper subsystems. The recently emerging canonical projector technique, stemming from iterative matrix chain construction, provides a theoretically sound a...

3D modeling of industrial parts is the key foundation and preceding step of 3D inspection and measurement of industrial parts. The common characteristic of industrial parts is that its surface is sleeky, homogeneous and lack of the texture. So the key difficulties in 3D modeling of industrial parts are the matching and the extraction of the suitable texture and the makeup of the 3D model. The p...

We derive an explicit formula for the fine-scale Green’s function arising in variational multiscale analysis. The formula is expressed in terms of the classical Green’s function and a projector which defines the decomposition of the solution into coarse and fine scales. The theory is presented in an abstract operator format and subsequently specialized for the advectiondiffusion equation. It is...