An Architectural Approach to the Design and Analysis of Cyber-Physical Systems

This paper presents an extension of existing software architecture tools to model physical systems, their interconnections, and the interactions between physical and cyber components. A new CPS architectural style is introduced to support the principled design and evaluation of alternative architectures for cyber-physical systems (CPSs). The implementation of the CPS architectural style in AcmeStudio includes behavioral annotations on components and connectors using either finite state processes (FSP) or linear hybrid automata (LHA) with plug-ins to perform behavior analysis using the Labeled Transition System Analyzer (LTSA) or Polyhedral Hybrid Automata Verifier (PHAVer), respectively. The CPS architectural style and analysis plug-ins are illustrated with an example

Sport, War and Democracy in Classical Athens

This article concerns the paradox of athletics in classical Athens. Democracy may have opened up politics to every class of Athenian but it had little impact on sporting participation. The city’s athletes continued to drawn predominantly from the upper class. It comes as a surprise then that lower-class Athenians actually esteemed athletes above every other group in the public eye, honoured them very generously when they won, and directed a great deal of public and private money to sporting competitions and facilities. In addition athletics escaped the otherwise persistent criticism of upper-class activities in the popular culture of the democracy. The research of social scientists on sport and aggression suggests this paradox may have been due to the cultural overlap between athletics and war under the Athenian democracy. The article concludes that the practical and ideological democratization of war by classical Athens legitimized and supported upper-class sport

View Consistency in Architectures for Cyber-Physical Systems

Abstract—Current methods for modeling, analysis, and design of cyber-physical systems lack a unifying framework due to the complexity and heterogeneity of the constituent elements and their interactions. Our approach is to define relationships between system models at the architectural level, which captures the structural interdependencies and some semantic interdependencies between representations without attempting to comprehend all of the details of any particular modeling formalism. This paper addresses the issue of defining and evaluating consistency between architectural views imposed by various heterogeneous models and a base architecture (BA) for the complete system. This notion of structural consistency ensures that the model elements adhere to the cyber and physical types and the connections between components present in the BA, which serves as the unifying framework for model-based development. Consistency checking between a model and the underlying system architecture is formulated as a typed graph matching problem between the connectivity graphs of the corresponding architectural view and the system’s BA. The usefulness of the approach to check system modeling assumptions is illustrated in the context of two heterogeneous views of a quadrotor air vehicle. Index Terms—system architecture; view consistency; graph morphism; multi-domain modeling; cyber-physical systems; I

Augmenting software architectures with physical components

Abstract: This paper presents an extension of existing software architecture tools to model physical systems, their interconnections, and the interactions between physical and cyber components. We introduce a new cyber-physical system (CPS) architectural style to support the construction of architectural descriptions of complete systems and to serve as the reference context for analysis and evaluation of design alternatives using existing model-based tools. The implementation of the CPS architectural style in AcmeStudio includes behavioral annotations on components and connectors using either finite state processes (FSP) or linear hybrid automata (LHA) with plug-ins to perform behavior analysis. The application of the CPS architectural style is illustrated for the STARMAC quadrotor

Quality Analysis of Dependable Systems: A Developer Oriented Approach

The quality of dependable systems (DS) is characterized by a number of non-functional properties (e.g., performance, reliability, availability, etc.). Assessing the DS quality against these properties imposes the application of quality analysis and evaluation. Quality analysis consists of checking, analytically solving, or simulating models of the system, which are specified using formalisms like CSP, CCS, Markov-chains, Petri-nets, Queuing-nets, etc. However, developers are usually not keen on using such formalisms for modeling and evaluating DS quality. On the other hand, they are familiar with using architecture description languages and object-oriented notations for building DS models. Based on the previous and to render the use of traditional quality analysis techniques more tractable, this paper proposes an architecture-based environment that facilitates the specification and quality analysis of DS at the architectural level