Discrete Event Specification Formalism Research Articles

Mobile Communications-Enabled Smart Grid Cosimulator System Design

In this article, we present a system design approach for a simulator constructed in MATLAB/Simulink used to simulate power systems and the underlying communication system, i.e., device-to-device (D2D) communication protocol stack of long-term evolution (LTE). Emphasis is placed on the characterization of the continuous time-discrete event (CT-DE) cosimulation interface used to develop this simulator. We model the mapping of communication links between D2D nodes as a bipartite digraph, and proceed to characterize the dynamics of information exchange between power system signals and LTE nodes using the discrete event specification formalism. The joint CT-DE dynamics were tested with a simple fault location, isolation, and restoration application. The results indicated that the control signal shifts in the power system simulator were synchronized with the appropriate LTE messaging dynamics.

A Formal Description Specification for Multi-Resolution Modeling Based on DEVS Formalism and its Applications

Multi-Resolution Modeling (MRM) is a relatively new research area. With the development of distributed interactive simulation, especially as the emergence of HLA (High Level Architecture), multi-resolution modeling becomes one of the key technologies for advanced modeling and simulation. But there is little research in the area of the theory of multi-resolution modeling, especially the formal description of MRM. In this paper, a new concept for the description of multi-resolution modeling, named Multi-resolution model Family (MF) is presented. A multi-resolution model family is defined as the set of different resolution models of the same entity. The description of MF includes two parts: models of different resolution and their relations. Based on this new concept and DEVS (Discrete Event Specification) formalism, a new multi-resolution model system specification, named MRMS (Multi-Resolution Model system Specification) is proposed. Some important properties of MRMS, especially the closure of MRMS under coupling operation are given and proved. MRMS provides a foundation and a powerful description tool for the research of MRM. An example to illustrate how to describe a multi-resolution model using our specification is given. Using this description, the theory and implementation of MRM can be further studied.

A Real-Time Discrete Event System Specification Formalismfor Seamless Real-Time Software Development

We present a time domain extension of the hierarchical and modular discrete event specification (DEVS) formalism. This extension is important for establishing a seamless real-time software development framework. Formalisms help describe a system unambiguously. If formal models are implemented without any consistent frameworks, however, it is hard to guarantee that there is no semantic gap between models and codes. Real-Time DEVS, named RTDEVS, is an extension of DEVS that can be characterized in three perspectives: the real time execution of models, the addition of time interval functions, and the activity specification for each state. After analyzing a system, the framework based on RTDEVS helps to expand each model of the system for executing in a real-time environment. In order to support the RTDEVS formalism, we propose abstract executive concepts based on the abstract simulator concepts of the DEVS formalism. Also, we implement an RTDEVS execution engine, named DEVS Executive, which runs on real-time Mach.