An alarm handling sequence can be described as consisting of a number of generic activity stages. These generic activities have been assembled into an analysis of alarm handling (Stanton et al., 1992; Stanton, 1994) a...
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An alarm handling sequence can be described as consisting of a number of generic activity stages. These generic activities have been assembled into an analysis of alarm handling (Stanton et al., 1992; Stanton, 1994) as shown in the present paper. The analysis distinguishes between routine events involving alarms and critical events involving alarms. Although the two type of events have most activities in common, critical events are distinctive by virtue of an investigative phase. It is proposed that the notion of AIA (alarm initiated activity) is used to describe the collective of the stages in alarm event handling. The term 'activities' is used to refer to the ensuing behaviours triggered by the presence of alarms. It is posited that these activities would not have been triggered without the alarm being present, thus alarm initiated activities. The AIAs are linked to other supervisory control activities which can be typified as continuous tasks (such as visual scanning of instruments and fine tuning of plant variables in response to minor variations in plant) and discrete tasks (such as putting plant into service and taking plant out of service).
SWOOPVR is a combination of the SWOOP mixed-mode industrial simulation language and VROOM VR graphics package. SWOOP is a simulation toolbox that runs under Turbo Pascal and allows the simulation of both discrete and ...
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SWOOPVR is a combination of the SWOOP mixed-mode industrial simulation language and VROOM VR graphics package. SWOOP is a simulation toolbox that runs under Turbo Pascal and allows the simulation of both discrete and continuous systems. On its own it allows simulation output as numerical data, statistical summaries, time-based graphs or 2-D animation. The VROOM graphics package can function independently as a VR toolbox, allowing the creation, placement and manipulation of 3-D objects within a virtual environment. VROOM runs on any 386 or 486 PC with only a VGA card required.
A novel clock alignment procedure for randomly dispersed mobiles is described and numerically modelled. The model is computer simulated using discrete-eventsimulation, incorporating procedures for time-stamping and s...
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A novel clock alignment procedure for randomly dispersed mobiles is described and numerically modelled. The model is computer simulated using discrete-eventsimulation, incorporating procedures for time-stamping and sub-netting. The model establishes a common local time within sub-net's under sub-net management control, which allows for both late net entries and early leavers. An example, using a number of mobiles dispersed over a wide geographical area, which have both random clock drift and random initial time offsets, is presented.
Most manufacturing oriented simulation languages only offer the facility to model the system in one mode: discrete or continuous. However if a real, single mode system is examined more closely, some characteristics of...
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Most manufacturing oriented simulation languages only offer the facility to model the system in one mode: discrete or continuous. However if a real, single mode system is examined more closely, some characteristics of the opposing mode can usually be found. It is to what extent that the opposing mode can be neglected that determines in which mode the system can be successfully modelled. For many systems it is not satisfactory to approximate to a single mode system, and a mixed-mode systemssimulation language would be required. A genuine mixed-mode simulation language would be able to model both discrete and continuous systems individually, in addition to combined continuous/discretesystems, and would therefore be a more useful general purpose simulation tool. It has been postulated that all systems should be treated as mixed-mode, with those with only discrete characteristics, or those with only continuous characteristics treated only as exceptions instead of the rule.< >
The traditional description of dynamic change in terms of (continuous) functions appears quite natural for many purposes. It is nevertheless not convenient when it comes to the analysis of particular system properties...
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The traditional description of dynamic change in terms of (continuous) functions appears quite natural for many purposes. It is nevertheless not convenient when it comes to the analysis of particular system properties. This talk exemplifies some of those properties and provides techniques to adequately specify, model and verify them.< >
discreteeventsystems can be modelled using a triple consisting of some alphabet (representing the events that might occur), and two trace sets (sets of possible strings) denoting the possible behaviour and the compl...
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discreteeventsystems can be modelled using a triple consisting of some alphabet (representing the events that might occur), and two trace sets (sets of possible strings) denoting the possible behaviour and the completed tasks of the system. Using this definition, the authors formulate and solve control problems and define the notion of deadlock. Distributed control is also discussed.< >
The underlying model for a discreteevent system is taken to be a finite graph (finite state system) with edges labeled by external or internal events and nodes labeled by attributes that facilitate useful definitions...
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The underlying model for a discreteevent system is taken to be a finite graph (finite state system) with edges labeled by external or internal events and nodes labeled by attributes that facilitate useful definitions of process operators. An attributed finite transition system is a quadruple of the (finite) set of states of a finite external event alphabet set, the transition relation and a function that maps the set of states into the state attribute set. The author discusses control and languages relating to this model, and presents theorems relating thereto.< >
An introduction to the theory of discreteevent dynamic systems is given. discreteevent dynamic systems (DEDS) are nonlinear in the conventional algebra, but are linear in the max-plus algebra. Of many concepts and r...
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An introduction to the theory of discreteevent dynamic systems is given. discreteevent dynamic systems (DEDS) are nonlinear in the conventional algebra, but are linear in the max-plus algebra. Of many concepts and results within the conventional linear algebra and linear systems theory, duplicates exist in the max-plus algebra and the theory of DEDS. The motivation to study DEDS comes from the description of flows in networks. Such networks are for instance related to computer systems, traffic systems and flexible manufacturing in production planning.< >
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