Volume 18, 1999, No. 4


COntext in artificial intelligence: I. A survey of the literature

P. Brézillon

Abstract. Context is the challenge for the coming years in artificial intelligence. In the companion paper [8], we present the main results of discussions at two workshops and at the first conference  focusing on the notion of context. In this paper, we present a view of how context is considered in knowledge acquisition, machine learning, communication, and databases and ontologies. We describe the way in which context is modelled and represented in the logic formalism and a rule-based formalism. We present briefly after some of the other approaches,  and sum up the different points that may be of interest for modelling context effectively.

 

Stochastic self-monitoring of autonomous systems

T. Kämpke

Abstract. A probabilistic method is presented for high level task planning of autonomous, mobile systems under partial observability of states and partial knowledge of transition laws. Partial state observability is addressed by directed Markov fields which support the detection of relationships between pairs of observed variables in competition to other such pairs.

 

models and parallel programming abstractions for synchronization and communication

A.E. Doroshenko, A.B. Godlevsky, L. Hluchý

Abstract. An approach based on algebraic treatment of programs and advanced transition system operational semantics is described for efficient synchronization  and communication of parallel coarse-grained distributed/shared memory programs. The approach combines compile/run time data flow analysis and buffering techniques and improves communication and synchronization features for these programs. This is accomplished in two ways: 1) construction of a number of semantic models  of data exchanges of increasing power for asynchronous communication in distributed environment, and 2) exploiting user-based specification of shared memory access order, known a priori, by means of synchronization facilities orthogonal to computation part of parallel programs that are more expressive and efficient than barrier-like facilities. Two new programming abstractions, exchange environs and forcing expressions, aimed at reducing communication and synchronization overhead, are elaborated from the theory. The program models constructed give more theoretical insight into the nature of parallelism of computation and communication and have immediate practical influence on parallel programming. Particularly automatic resolution of some classes of communication deadlocks is allowed and enhancement of data parallel paradigm of computation can be provided.

 

on the structure of armstrong relation for generalized positive boolean dependencies

Le Thi Thanh

Abstract. An Armstrong relation for a set of GPBDs is a relation that satisfies each GPBD implied by the set but no GPBD that is not implied by it.

 

polynomial time manhattan routing without doglegs - a generalization of gallai's algorithm

E. Boros, A. Recski, T. Szkaliczki, F. Wettl

Abstract. Gallai's classical result on interval packing can be applied in VLSI routing to find, in linear time, a minimum/width dogleg/free routing in the Manhattan model, provided that all the terminals are on one side of a rectangular [1]. Should the terminals appear on two opposite sides of a rectangular, the corresponding "channel routing problem" is NP/complete [2,3]. We generalize Gallai's result for the case if the terminals appear on two adjacent sides of the rectangular.

 

Grapnel to C translation in the grade environment

D. Drótos, P. Kacsuk

Abstract. This paper describes behaviour of source code generator of GRADE system which is a graphical programming environment to help programmers develop, write, execute, and verify parallel programs for distributed environments. The described tool is a translator which automatically converts graphical representation of the developed program into C source code.


Go To Contents