We are interested in modeling behaviors and verifying properties of systems in which time and concurrency play a crucial role. We introduce a model of distributed automata which are equipped with event clocks as in [3], which we call Event Clock Message Passing Automata (ECMPA). To describe the behaviors of such systems we use timed partial orders (modeled as message sequence charts with timing...

We solve some decision problems for timed automata which were raised by Tripakis in [9] and by Asarin in [3]. In particular, we show that one cannot decide whether a given timed automaton is determinizable or whether the complement of a timed regular language is timed regular.

This paper proposes a new timed model named nested timed automata (NeTAs). An NeTA is a pushdown system whose stack symbols are timed automata (TAs). It either behaves as the top TA in the stack, or switches from one TA to another by pushing, popping, or changing the top TA of the stack. Different from existing component-based context-switch models such as recursive timed automata and timed rec...

We consider pushdown timed automata (PTAs) that are timed automata (with dense clocks) augmented with a pushdown stack. A configuration of a PTA includes a state, dense clock values and a stack word. By using the pattern technique, we give a decidable characterization of the binary reachability (i.e., the set of all pairs of configurations such that one can reach the other) of a PTA. Since a ti...

Veriication of timed bisimulation equivalence is generally diicult because of state explosion caused by concrete time values. In this paper, we propose a veriication method to verify timed bisimulation equivalence of two timed processes using a symbolic technique similar to (Hennessy and Lin 1995). We rst propose a new model of timed processes, Alternating Timed Symbolic Labelled Transition Sys...

[Purpose] This study aimed to determine the correlation between center of pressure and functional balance in non-faller elderly practitioners of Tai Chi. [Subjects and Methods] For the study, nine non-faller elderly practitioners of Tai Chi who were able to maintain a standing posture and walk independently were recruited. Timed one-leg standing and timed up-and-go tests were used as functional...

In the development of real-time (communicating) hardware or embedded-software systems, it is frequently the case that we want to refine/optimize the system’s internal behavior while preserving the external timed I/O behavior (that is, the interface protocol). In such a design refinement, modification of the systems’ internal branching structures, as well as re-scheduling of internal actions, ma...

Condition/Event systems 14] represent a continuous{time modeling framework used in control theory within the eld of discrete event dynamic systems. This model has been extended in 7] to include real{time aspects. Timed automata 2] are a widely accepted model for real{time systems. They have been intensively studied from diierent points of view leading to a variety of tools that analyze real{tim...