9,827 research outputs found
Data linkage algebra, data linkage dynamics, and priority rewriting
We introduce an algebra of data linkages. Data linkages are intended for
modelling the states of computations in which dynamic data structures are
involved. We present a simple model of computation in which states of
computations are modelled as data linkages and state changes take place by
means of certain actions. We describe the state changes and replies that result
from performing those actions by means of a term rewriting system with rule
priorities. The model in question is an upgrade of molecular dynamics. The
upgrading is mainly concerned with the features to deal with values and the
features to reclaim garbage.Comment: 48 pages, typos corrected, phrasing improved, definition of services
replaced; presentation improved; presentation improved and appendix adde
An Agent-Based Approach to Self-Organized Production
The chapter describes the modeling of a material handling system with the
production of individual units in a scheduled order. The units represent the
agents in the model and are transported in the system which is abstracted as a
directed graph. Since the hindrances of units on their path to the destination
can lead to inefficiencies in the production, the blockages of units are to be
reduced. Therefore, the units operate in the system by means of local
interactions in the conveying elements and indirect interactions based on a
measure of possible hindrances. If most of the units behave cooperatively
("socially"), the blockings in the system are reduced.
A simulation based on the model shows the collective behavior of the units in
the system. The transport processes in the simulation can be compared with the
processes in a real plant, which gives conclusions about the consequencies for
the production based on the superordinate planning.Comment: For related work see http://www.soms.ethz.c
Modelling and analysing user views of telecommunications services
User views of calls are modelled by behaviour trees, which are synchronised to form a network of users. High level presentations of the models are given using process algebra and an explicit theory of features, including precedences. These precedences abstractly encapsulate the possible state spaces which result from different combinations of features.
The high level presentation supports incremental development of features and testing and experimentation through animation. Interactions which are not detected during the experimentation phase may be found through static analysis of the high level presentation, through dynamic analysis of the under-lying low level transition system, and through verification of temporal properties through model-checking. In each case, interactions are resolved through manipulation of the feature precedences
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