Exdasy
- a user friendly and extendable
data distribution system
R.Ch.
Koppler, G. Kurka, J.J. Volkert
Abstract.
This paper introduces Exdasy - a user friendly and extendable software tool for
partitioning unstructured meshes and mapping mesh partitions to parallel
computers. Exdasy was designed to meet the increasing demands to today's
data distribution systems, which are posed by the variety of mesh
computations, the ongoing development of distribution algorithms, and rapid
changes in parallel hardware technology. For this, Exdasy offers third-party
state-of-the-art distribution algorithms augmented with graphical user
interfaces and powerful graphical evaluation displays. Evaluation of
distributions is based on various quality metrics and static machine parameters.
Exdasy provides a modular architecture by means of replaceable
distribution algorithms, machine models and evaluation facilities. Hereby it is
attractive to both users and developers.
context
in artificial intelligence
II. key elements of contexts
P.
Brézillon
Abstract.
Context is the challenge for
the coming years in artificial intelligence. In the companion paper [6], we
present a view of how context is considered through the literature in various
domains. In this paper, we present the main results of discussions at some
workshops and the first conference focusing on the notion of context.
We point out the opposition between two viewpoints on context, namely the
engineering and the cognitive ones. We show that this opposition is only
superficial because they do not consider context at the same level, one is at
the level of the knowledge representation, the other at the level of the
interaction between two agents.
Epistasis
and unitation
M.T.
Iglesias, C. Vidal, D. Suys, A. Verschoren
Abstract.
Normalized epistasis measures
links between separate bits in binary strings, used to represent data to be
optimized with respect to a given fitness function. In this note, we explicitly
calculate the epistasis of unitation function, i.e., fitness functions f whose value only depends upon the number of ones or zeroes in the
string on which f acts.
A
VDM approach to continuation-based semantics of Prolog
T.K.
Shih, H.-C. Keh, Y.-C. Lin
Abstract.
VDM is short for Vienna
Development Method which was developed in the early 1960's in the IBM Vienna
Laboratory. VDM
was used in language definition and compiler design. It was then extended to
include aspects of large project designs. We use VDM as a semantic tool to
discuss the continuation semantics of Prolog. A continuation represents the
dynamic effect of the remainder of a program. Based on the semantic functions, a
metalevel interpreter is constructed showing the result of our work.
Exploiting
type analysis for unification
in a distributed environment
E.
Lamma, P. Mello, C. Stefanelli, P. van Hentenryck
Abstract.
Unification, in distributed
implementations of logic programming, involves sending and receiving messages to
access data structures spread among different nodes.
In traditional implementations, processes access remote data structures
by exchanging messages which carry either the overall data structures or only
remote references to them. Intermediate but fixed solutions are also possible.
These fixed policies can be far from optimal on various classes of
programs and may induce substantial overhead. This paper presents an
implementation scheme for distributed logic programming which consists of
tailoring the copying level for each procedure argument. The scheme is based on
a consumption specification which describes the way each procedure
"consumes" its arguments locally. Consumption specification avoids
unnecessary copying and allows to request data structures globally. The
consumption specification (or an approximation of it) can be obtained through a
static analysis inspired by traditional type analyses. The paper presents two
implementations which exploit the consumption specification. The low-level
implementation extends the Warren Abstract Machine with instructions and data
structures for exploiting the consumption specification during code compilation.
The high-level implementation is based on attributed variables in order to
capture and implement, at a higher-level, distributed unification. Experimental
results of the high-level implementation on a network of workstations show the
potential of the approach.