We present a formal (model-based) approach to describing and analysing access control policies. This approach allows us to evaluate access requests against policies, compare versions of policies with each other and check policies for internal consistency. Access control policies are described using VDM, a statebased formal modelling language. Policy descriptions are concise and may be easily ma...

Industrial Process Measurement and Control Systems (IPMCS) are used in most of the industrial sectors to achieve production improvement, process optimisation and time and cost reduction. Integration, reuse, flexibility and optimisation are demanded to adapt to a rapidly changing and competitive market. There is also a growing requirement that all software tools that support the different phases...

Motivation In many instances, programs are concerned only with processing or manipulating data and displaying them to a user, who becomes the agent that ends up taking physical action. However, in some instances, we create software to control other analog devices or machinery directly. We call these hybrid systems because they exhibit a mixture of discrete behavior from the software and continu...

FORMAL MODEL AND ANALYSIS OF USAGE CONTROL Xinwen Zhang, Ph.D. George Mason University, 2006 Dissertation Director: Ravi S. Sandhu Dissertation Co-director: Francesco Parisi-Presicce The concept of usage control (UCON) was introduced as a unified approach to capturing a number of extensions for access control models and systems. In UCON, a control decision is determined by three aspects: author...

With the ever-growing interest in the usage of minimally-invasive surgery, surgical robots are also being extensively used in the operation theaters. Given the safety-critical nature of these surgeries, ensuring the accuracy and safety of the control algorithms of these surgical robots is an absolute requirement. However, traditionally these algorithms have been analyzed using simulations and t...

From a safety point of view different transportation systems share many properties and requirements. They are all supposed to function correctly, to be failure tolerant and to be associated with only minimal risk. To ensure these requirements formal methods are a great help. The ForMoSA approach provides an integrated methodology for formally analyzing safety-critical transportation systems. On...

We formally verify hybrid safety properties of cooperation protocols in a fully parametric version of the European Train Control System (ETCS). We present a formal model using hybrid programs and verify correctness using our logic-based decomposition procedure. This procedure supports free parameters and parameter discovery, which is required to determine correct design choices for free paramet...

In many applications, ontology-based technologies will be only only be successful if they support access control and provenance tracking. In this paper we present a novel approach to implementation of both access control and provenance in deductive information systems. A key feature of our approach is the explicit representation of speech acts as well as sentence tokens that are used to encode ...

This paper proposes a complexity management methodology for fuzzy systems with feedback rule bases. The methodology is based on formal methods for presentation, manipulation and transformation of fuzzy rule bases. First, Boolean matrices are used for formal presentation of rule bases. Then, binary merging operations are used for formal manipulation of rule bases. Finally, repetitive merging ope...