Volume
17, 1998, No. 6
knowledge
interpolation: A simple approach to rapid symbolic reasoning
N. Chatterjee, J.A. Campbell
Abstract.
The non-algorithmic nature of
traditional knowledge-based (KB) reasoning approaches makes these techniques
open-ended. As a result, KB techniques appear unsuitable for real-time
applications as is evident from the small number of appearances of KB techniques
in real-time domains. The technique of knowledge
interpolation is a potential remedy for the shortcoming. Intuitively, the
technique imitates the numerical-analysis technique of interpolation, derives
solutions for an unknown problem from some already known values, and thereby
avoids extensive searches of the knowledge base.
an extra inherent advantage is that it gives the computation a more
predictable algorithmic character. Hence not only can a computation's temporal
requirements be estimated, but also requirements themselves may be reduced
significantly.
Effective
application of this technique needs to answer two questions: what are the
prerequisites for application of such techniques, and what are the possible ways
of application. This paper studies both issues from an implementational point of
view.
PM-colonies
C. Martín-Vide, Gh. PĂun
Abstract.
A colony is meant to be a
symbol manipulating system consisting of as simple as possible components which
behave in a cooperative way such that the collective competence is strictly
larger (even significantly larger)
than the component competences. We introduce here colonies whose agents can only
perform point mutation (hence the
abbreviation PM) transformations of the common string (which represents the environment
of the colony), in a vicinity of the agent. In this way, important notions of
this area, such as
localization of agents, parallelism, lack of internal representation,
agent interaction, come into stage in a very natural way. In contrast with the
simplicity of the involved agents, the behavior of PM-colonies is quire
intricate: many problems concerning the "life" of a colony are not
algorithmically solvable, the number of agents in the colony or simultaneously
present in the environment defines infinite hierarchies of languages, etc. Such
results show that the behaviour of PM-colonies is not predictable and that their
behaviour is significantly synergetic.
A
unified approach to FAST computation of discrete sinusoidal transforms I: DCT
and DST transforms
V. BRITẢÁK
Abstract.
A unified approach to the fast computation of orthogonal discrete sinusoidal
transforms for real data sequences is presented. Various types of discrete
sinusoidal transforms (DCT) and discrete sine transform (DST are members of
discrete sinusoidal transform family. The unified approach
takes advantage of a regular universal computational structure both for
the DCT/DST type II (DCT-II(DST-II) and type III (DCT-III/DST-III) computation
in existing real sparse matrix factorizations leading to simple, numerically
stable, in place
and efficient algorithms for any N = 2m,
m > 0. The computational complexity of all algorithms both in the sense
of the number of arithmetic operations and structural simplicity is better or
identical compared with the best known algorithms. The proposed generalized
signal flow graphs are regular and confirm the importance of the universal
DC-/II/DST-II (DCT/III/DST-III) computational structure for its implementation
on one VLSI chip.
Computing
the singular values of a complex matrix using one-sided Jacobi method on the
intel-paragon machine
S. ROBERT
Abstract. An algorithm for computing the singular values of a complex matrix based on Rijk's improvement of the one-sided Jacobi method [12] is developed. The aim was to find the most efficient Jacobi algorithm for the complex case retaining the same characteristics of numerical stability. Its parallelisation is given for MIMD machines and in particular the tests have been done on the Intel-Paragon machine with an estimation of a maximum of 55% gain in computation time between the classical algorithm and the improved one.