Abstract
The coordinate change eigenvalues for the MacKay and van Zeijts period doubling renormalisation operator for bimodal 1D maps are derived. They are found in numerical computations of the spectrum at all the periodic orbits of renormalisation of period up to five.

Abstract
The increasing complexity of mixed-signal boards makes an integrated analogue/digital testability approach an attractive proposition. This paper investigates one such approach based on the use of mixed-signal test support ICs together with standard board level test infrastructures. The architecture of a test support IC and preliminary experimental results are also presented.

Abstract
This paper describes CA/C++, Concurrency Annotations in C++, a language extension that regulates method invocations from multiple threads of execution in a shared-memory multiprocessor system. This system provides threads as an orthogonal element to the language, allowing them to travel through more than one object. Statically type-ckecked synchronous and asynchronous method invocations are supported, with return values from asynchronous invocations accessed through first claw future-like objects. Method invocations are regulated with synchronization code defined in a separate class hierarchy, allowing separate definition and inheritance of synchronization mechanisms. Each method is protected by an access flag that can be switched in pre and post-actions, and by a predicate. Both must evaluate to true in order to enable a thread to animate the method code. Flags and method predicates are independently redefinable along the inheritance chain, thus avoiding the inheritance anomaly.

Abstract
The paper discusses the need of a test infrastructure to support the testing of mixed-signal electronic systems, and discusses a general architecture for test support ICs that can be used to build it. An implementation of a subset of this architecture is described together with its application in a practical example.

Abstract

Abstract
In this paper we show how an understanding of a dynamic system from the point of view of the tasks that it supports and an understanding of human error can guide a process of deriving human error tolerance requirements. Our aim is to provide a means whereby, rather than relying on training as a means of improving operator performance, designers may develop interactive systems with human error tolerance in mind. We extend an established methodology (SHARP) by employing a software engineering notation (CSP) that provides a bridge between a theory of error and the practice of design and implementation. In this paper we outline approaches to human error, describe a task notation based on CSP which helps us to elicit requirements on human-error tolerance expressed as functional properties of the system. The technique is used to analyze an engine fire recovery procedure in order to derive human error tolerance requirements.