Nonconflict check by using sequential automaton abstractions

In Ramadge-Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed over relatively small automata, even though the original system can be fairly large

Verdieping bewaken en beveiligen, editie juli 2023 (2/2023)

De ‘Verdieping Bewaken en Beveiligen’ brengt verdieping aan op actuele gebeurtenissen en ontwikkelingen gerelateerd aan het stelsel Bewaken en Beveiligen. Deze Verdieping wordt aangeboden aan experts die werkzaam zijn bij de stelselpartners en de ketenpartners van het stelsel. Daarnaast wordt dit product aangeboden aan geïnteresseerden in een bredere kring rond het stelsel, waaronder academici, journalisten en politici.Security and Global Affair

On the Validity of the Radiographic Method for Determining Age of Ancient Salmon

White rings visible on the centrum face of salmon vertebrae with X-rays have been used since the 1980s to age Pacific salmon (Oncorhynchus spp.), which in turn have been used to determine salmon species, season of capture and season of site occupation. This approach relies on a variety of assumptions, the most fundamental of which is that rings represent true years. Recent aDNA analysis has shown that the X-ray approach has flaws but the source of the error has been unknown. Given the value of reconstructing salmon population demographics and life history from ancient remains, establishing a valid and reliable method of ageing salmon vertebrae is extremely worthwhile. The main goal of our study was to evaluate if X-ray images of ring patterns on vertebrae provide a valid method of estimating fish age. Vertebrae from 66 adult Chinook salmon (O. tshawytscha) of known age were studied with X-rays, thin sections or low-powered (10–30 ×) magnification. We found that the white bands observed in X-rays are structural walls that do not grow annually. While X-rays are not a valid method for ageing salmonids, incremental growth seen on the surface of fish centra shows great promise for reconstructing ancient fish life history

Efficient nonconflict check by using automaton abstractions

In Ramadge-Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed on relatively small automata, even though the original system can be fairly large.</p

Efficient nonconflict check by using automaton abstractions

In Ramadge-Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed on relatively small automata, even though the original system can be fairly large

Nonconflict check by using sequential automaton abstractions

In Ramadge–Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by the composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed on relatively small automata, even though the original product system can be fairly large

Nonconflict check by using sequential automaton abstractions Citation for published version (APA): Nonconflict Check by Using Sequential Automaton Abstractions

Abstract In Ramadge-Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed over relatively small automata, even though the original system can be fairly large

Nonconflict check by using sequential automaton abstractions

In Ramadge–Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by the composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed on relatively small automata, even though the original product system can be fairly large

Nonconflict check by using sequential automaton abstractions

In Ramadge–Wonham supervisory control theory we often need to check nonconflict of plants and corresponding synthesized supervisors. For a large system such a check imposes a great computational challenge because of the complexity incurred by the composition of plants and supervisors. In this paper we present a novel procedure based on automaton abstractions, which removes internal transitions of relevant automata at each step, allowing the nonconflict check to be performed on relatively small automata, even though the original product system can be fairly large

Syntax and Formal Semantics of Chi 2.0 12

This report defines the syntax and formal semantics of the Chi 2.0 formalism. The Chi formalism integrates concepts from dynamics and control theory with concepts from computer science, in particular from process algebra and hybrid automata. It combines a high expressivity and ease of modeling with a formal semantics. The Chi language is defined by means of an abstract and a concrete syntax. The purpose of the abstract syntax is to allow a straightforward definition of the structured operational semantics (SOS), which associates a hybrid transition system with a Chi process. The Chi Semantics is compositional, and bisimulation is a congruence for all operators. The concrete syntax offers modeling equivalents for the elements of the abstract syntax, and it introduces new syntax to ensure better readability and easier modeling. The meaning of the concrete syntax is defined by means of a mapping to the abstract syntax. The Chi language provides among others discrete, continuous, and algebraic variables, and equation process terms for modeling differential algebraic equations (DAEs), including fully implicit or switched DAEs. Steady state initialization can be specified, and higher index DAEs in Chi are equivalent to the corresponding index 1 DAEs, obtained after differentiation of the hidden constraints. The invariant process term in Chi corresponds to invariants in hybrid automata The following operators are provided (among others): the parallel composition, alternative composition (choice), and sequential composition operators; and the recursion scope operator for modeling automata. The parallel composition operator allows shared variables, shared synchronizing and non-synchronizing action labels, and shared CSP channels for synchronous communication. Two main ways of expressing urgency are provided: First, action labels and channels can be declared as urgent. Delaying is possible only if, and for as long as no urgent actions are enabled. Synchronizing actions are enabled only when the guards of all participating actions in a parallel composition are enabled. Second, urgency can be defined locally by means of the time can progress (tcp) process term, which allows delays for as long as the tcp predicate is true. Scope operators are available for hierarchical modeling. They are used to declare local variables, local action labels, and local channels. Process definition and instantiation provide process re-use and encapsulation. Hybrid automata and networks of hybrid automata can easily be expressed in Chi. Since Chi is a process algebra, its operators can be arbitrarily combined, resulting in a high modeling flexibility