Authors:
Jingshan Li,
Semyon M. Meerkov,
Volume: 1, Page 400 Paper number 1224
Abstract:
The problem of customer demand satisfaction in production systems with
unreliable machines and finite Finished Goods Buffers (FGB) is addressed.
The measure of customer demand satisfaction, referred to as the Due-Time
Performance (DTP), is characterized by the probability to ship to the
customer a required number of parts during a fixed time interval. A
method for DTP calculation is developed and applied within a case study.
Authors:
Fumio Ishizaki,
Volume: 1, Page 406 Paper number 1851
Abstract:
We consider a discrete-time single-server priority queueing system
where the arrival process is comprised of feedback controlled streams
and non-renewal streams. Such a priority queueing system frequently
appears in various applications. For the priority queueing systems,
we develop an on-line concurrent performance estimation technique,
which uses a proportional relation between the stationary distributions
of the queueing systems with different buffer capacity. Our technique
is useful to various controls for dynamic buffer allocation in multimedia
networks.
Authors:
Ross Baird,
Maria Celeste Colantonio,
Sandro Macchietto,
Volume: 1, Page 412 Paper number 1862
Abstract:
This paper introduces Hierarchical Procedural Control Theory. It builds
on the properties of Decomposition Theory to provide a mechanism to
tackle large scale problems in synthesising sequential controllers
for discrete-event batch operations. The generic behaviour of all
the controllers is modelled as a finite state machine (FSM), enabling
them to be combined and operated in series and parallel by other sequential
controllers in a hierarchical structure. An application to a Clean
in Place process in a Batch Pilot Plant is shown.
Authors:
Haoxun Chen,
Hans-Michael Hanisch,
Volume: 1, Page 418 Paper number 1096
Abstract:
A model aggregation approach is developed for discrete event systems
described by condition/event automata, a class of condition/event systems.
It is based on input-output equivalence of the systems. With the approach,
a higher level model of a plant in the hierarchical control synthesis
of discrete event systems can be derived from a lower level model by
hiding insignificant states and events while keeping the input-output
behaviour of the plant invariant in view of the higher level.
Authors:
Francesco Basile,
Pasquale Chiacchio,
Alessandro Giua,
Volume: 1, Page 424 Paper number 1920
Abstract:
The classical partition of the event set into controllable and uncontrollable
events from supervisory control theory is replaced by introducing the
concept of control and observation cost of an event. This leads naturally
to consider an optimal control problem for a given logical control
specification. Here the case of generalized mutual exclusion constraint
is considered for a Petri net plant. It has been shown that a constraint
of this kind may be enforced via a monitor place. In this paper we
propose an integer programming approach to synthesize the optimal monitor
so as to minimize a given cost.
Authors:
Xiaolan Xie,
Volume: 1, Page 430 Paper number 1456
Abstract:
Performance evaluation and optimization of failure-prone discrete event
systems are addressed in this paper. Our analysis is based on a fluid
stochastic event graph model that is a decision-free Petri net. In
a fluid Petri nets, each place holds a continuous flow instead of discrete
tokens of conventional Petri nets. A transition can be in operating
state or in failure state. A transition in operating state can fire
at its maximal speed and a transition in failure state cannot fire.
Jumps between failure and operating states are independent of the firing
conditions and the sojourn time in each state is a random variable
of general distribution. For performance evaluation, a set of evolution
equations that determines continuous state variables at epochs of discrete
events is established. Based on the evolution equations, we prove that
the cumulative firing of transitions are Lipschitz continuous, non-decreasing
and concave functions of system parameters including maximal firing
rates and the initial marking. Gradient estimators of the cumulative
firings with respect to the system parameters are derived and their
properties established. Finally, an optimization problem of the system
parameters that maximizes a concave function of throughput rate and
the system parameters is addressed.
Authors:
Dimitri Lefebvre,
Volume: 1, Page 436 Paper number 1008
Abstract:
This work deals with optimal flow control for manufacturing systems
that are modelled by continuous Petri nets. The control design consists
in defining the time intervals while the machines are working and the
time intervals while they are not, in order to minimise the production
cost. Results are discussed and compared with the ones obtained with
the Wilson model.
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