Simple lower and upper bounds on mean cycle time in stochastic acyclic fork-join queueing networks are derived using a (max,+)algebra based representation of network dynamics. The behaviour of the bounds under various assumptions concerning the service times in the networks is discussed, and related numerical examples are presented. Key-Words: (max,+)-algebra, dynamic state equation, acyclic fo...

An expert system shell (SYSTEM Z-II) based on fuzzy logic and numbers was built in a minicomputer environment. Z-II wss proved to be a successful and powerful expert system building tool because it can handle both exact and inexact reasoning. Its third generation, Z-III, is developed in a PC environment and includes some new enhancement features compared to Z-II. In this paper, the development ...

a r t i c l e i n f o We examine the role of liquidity risk, both as a stock characteristic as well as systematic liquidity risk, in UK mutual fund performance for the first time. We find that on average UK mutual funds are tilted towards liquid stocks (except for small stock funds as might be expected) but that, counter-intuitively, liquidity rather than illiquidity, as a stock characteristic ...

While intrusion detection systems are becoming ubiquitous defenses in today's networks, currently we have no comprehensive and scientifically rigorous methodology to test the effectiveness of these systems. This paper explores the types of performance measurements that are desired and that have been used in the past. We review many past evaluations that have been designed to assess these metric...

The decoupled control of torque and flux has made field-oriented control an attractive choice for high performance induction motor drives. However, changes in the speed tracking trajectory and external disturbances make it difficult to achieve an acceptable closed-loop tracking performance, especially when traditional linear controllers are used. This paper addresses this issue by applying dire...

In earlier work we introduced a generic, modular tracker architecture that combines the advantages of several simple and rapidly performing tracking algorithms. The adaptive choice of critical system parameters such as processing regions and resolution results in robustness to varying frame rates and computational constraints. In this paper, we describe the embedding of our tracker into a distr...

Measurements are of fundamental importance for performance evaluation since they provide a picture of the behavior of the systems and of their load Experimental approaches to workload characterization are based on the application of techniques for the interpretation and the anal ysis of measurements A survey of the methodologies for modelling the load of various types of systems namely interact...