FollowMe: A Bigraphical Approach

In this paper we illustrate the use of modelling techniques using bigraphs to specify and refine elementary aspects of the FollowMe framework. This framework provides the seamless migration of bi-directional user interfaces for users as they navigate between zones within an intelligent environment

Towards a bigraphical encoding of actors

Actors are self-contained, concurrently interacting entities of a computing system. They can perform local computations, communicate via asynchronous message passing with other actors and can be dynamically created. Bigraphs are a fully graphical process algebraic formalism, capable of representing both the position in space of agents and their inter-connections. Their behaviour is specified by a set of reaction rules. In this paper, we present a bigraphical encoding of a simplified actor language with static topology. We express actor configurations in terms of sorted bigraphs while the rules of the actor operational semantics are encoded by bigraphical reactive rules

Distributed execution of bigraphical reactive systems

The bigraph embedding problem is crucial for many results and tools about bigraphs and bigraphical reactive systems (BRS). Current algorithms for computing bigraphical embeddings are centralized, i.e. designed to run locally with a complete view of the guest and host bigraphs. In order to deal with large bigraphs, and to parallelize reactions, we present a decentralized algorithm, which distributes both state and computation over several concurrent processes. This allows for distributed, parallel simulations where non-interfering reactions can be carried out concurrently; nevertheless, even in the worst case the complexity of this distributed algorithm is no worse than that of a centralized algorithm

Bigraphical Refinement

We propose a mechanism for the vertical refinement of bigraphical reactive systems, based upon a mechanism for limiting observations and utilising the underlying categorical structure of bigraphs. We present a motivating example to demonstrate that the proposed notion of refinement is sensible with respect to the theory of bigraphical reactive systems; and we propose a sufficient condition for guaranteeing the existence of a safety-preserving vertical refinement. We postulate the existence of a complimentary notion of horizontal refinement for bigraphical agents, and finally we discuss the connection of this work to the general refinement of Reeves and Streader.Comment: In Proceedings Refine 2011, arXiv:1106.348

A Formal Framework for Modeling Context-Aware Behavior in Ubiquitous Computing

Abstract. A formal framework to contextualize ontologies, proposed i

Design-time formal verification for smart environments: an exploratory perspective

Smart environments (SmE) are richly integrated with multiple heterogeneous devices; they perform the operations in intelligent manner by considering the context and actions/behaviors of the users. Their major objective is to enable the environment to provide ease and comfort to the users. The reliance on these systems demands consistent behavior. The versatility of devices, user behavior and intricacy of communication complicate the modeling and verification of SmE's reliable behavior. Of the many available modeling and verification techniques, formal methods appear to be the most promising. Due to a large variety of implementation scenarios and support for conditional behavior/processing, the concept of SmE is applicable to diverse areas which calls for focused research. As a result, a number of modeling and verification techniques have been made available for designers. This paper explores and puts into perspective the modeling and verification techniques based on an extended literature survey. These techniques mainly focus on some specific aspects, with a few overlapping scenarios (such as user interaction, devices interaction and control, context awareness, etc.), which were of the interest to the researchers based on their specialized competencies. The techniques are categorized on the basis of various factors and formalisms considered for the modeling and verification and later analyzed. The results show that no surveyed technique maintains a holistic perspective; each technique is used for the modeling and verification of specific SmE aspects. The results further help the designers select appropriate modeling and verification techniques under given requirements and stress for more R&D effort into SmE modeling and verification researc

Bigraphical Domain-specific Language (BDSL): User Manual

This report describes Bigraphical DSL (BDSL), a domain-specific language for reactive systems, rooted in the mathematical spirit of the bigraph theory devised by Robin Milner. BDSL is not only a platform-agnostic programming language but also a development framework for reactive applications, written in the Java programming language, with a focus on stability and interoperability. The report serves as a user manual mainly elaborating on how to write and execute BDSL programs, further covering several features such as how to incorporate program verification. Moreover, the manual procures some best practices on design patterns in form of code listings. The BDSL development framework comes with a ready-to-use interpreter and may be a helpful research tool to experiment with the underlying bigraph theory. The framework is further intended for building reactive applications and systems based on the theory of bigraphical reactive systems.:1 Introduction 1.1 Bigraphical Reactive Systems and Programming . . . . . 1.2 Installation 1.3 How to write and run BDSL programs? 1.4 Further Help 1.5 Remarks 2 General Usage of the BDSL Interpreter Tool 2.1 The CLI Interpreter of BDSL 2.2 Supplying a BDSL Program to the Interpreter 2.3 Externalized Configuration 3 BDSL Program Structure 3.1 Elements of a BDSL program 3.2 Main Block 3.3 Scoping, Namespaces and Imports 3.4 Classes and Variables 3.5 Event Listeners/Callbacks 4 Predefined Methods in BDSL 4.1 Printing to the Console 4.2 Loading Bigraphs 4.3 Synthesizing Random Bigraphs 4.4 Exporting Bigraph Variables 4.5 Executing BRSs 5 Examples 5.1 Basic Mathematical Calculations the Bigraphical Way 5.2 Importing External Libraries 5.3 Pathfinding: Naive Blind Search 5.4 Mutual Exclusion Problem 6 Advanced Topics 6.1 User-defined Functions 6.2 Using the Interpreter Programmatically 6.3 IDE Support 7 Conclusion 7.1 Future Work References Appendix A Configuration File for the BDSL Interpreter B BDSL Sample Programs C Using the BDSL Interpreter Programmaticall