arXiv subjects

K. Ritsuka

Publications and source records attributed to K. Ritsuka.

4 recordsLinked to original sources

arXiv2022

A Uniform Approach to Compare Architectures in Decentralized Discrete-Event Systems

Solutions to decentralized discrete-event systems problems are characterized by the way local decisions are fused to yield a global decision. A fusion rule is colloquially called an architecture. Current approaches do not provide a direct way to compare existing architectures. Determining whether an architecture is more permissive than another architecture had relied on producing examples ad hoc and on individual inspiration that puts the conditions for solvability in each architecture into some form that admits comparison. In response to these research efforts, a method based on morphisms between graphs has been extracted to yield a uniform approach to compare the permissiveness of the architectures.

eess.SY↗

arXiv2022

Do What You Know: Coupling Knowledge with Action in Discrete-Event Systems

An epistemic model for decentralized discrete-event systems with non-binary control is presented. This framework combines existing work on conditional control decisions with existing work on formal reasoning about knowledge in discrete-event systems. The novelty in the model presented is that the necessary and sufficient conditions for problem solvability encapsulate the actions that supervisors must take. This direct coupling between knowledge and action -- in a formalism that mimics natural language -- makes it easier, when the problem conditions fail, to determine how the problem requirements should be revised.

cs.AI↗

arXiv2022

Equivalence of Decentralized Observation, Diagnosis, and Control Problems in Discrete-event Systems

This paper demonstrates an equivalence between observation problems, control problems (with partial observation), and diagnosis problems of decentralized discrete-event systems, namely, the three classes of problems are Turing equivalent, as one class Turing reduces to another. The equivalence allows decomposition of a control problem into a collection of simpler control sub\-/problems, which are each equivalent to an observation problem; and similarly allows converting a diagnosis problem to a formally simpler observation problem. Since observation problems in their most general formulation have been shown to be undecidable in previous work, the equivalence produced here demonstrates that control problems are also undecidable; whereas the undecidability of diagnosis problems is a known result.

eess.SY↗

arXiv2022

A Framework for the High-Level Specification and Verification of Synchronous Digital Logic Systems

A syntactic model is presented for the specification of finite-state synchronous digital logic systems with complex input/output interfaces, which control the flow of data between opaque computational elements, and for the composition of compatible systems to form closed-loop systems with no inputs or outputs. This model improves upon similar existing models with a novel approach to specifying input and output ports in a way which is uniform and symmetric. An automaton model is also presented for encoding arbitrary computational processes, and an algorithm is presented to generate an automaton representation of a closed-loop system. Using the automaton model, the problem of timing-agnostic verification of closed-loop systems against a desired behavioural specification, encoded as the similarity of closed-loop systems in terms of the set of computations performed, is shown to be decidable. The relationship between the models and real-world implementations of systems is discussed.

cs.LO↗