Modelling information resources and their salience in medical device design

location: Brussels, Belgium accepted: March 30 2016location: Brussels, Belgium accepted: March 30 2016location: Brussels, Belgium accepted: March 30 2016The paper describes a model that includes an explicit description of the information resources that are assumed to guide use, enabling a focus on properties of “plausible interactions”. The information resources supported by an interactive system should be designed to encourage the correct use of the system. These resources signpost a user’s interaction, helping to achieve desired goals. Analysing assumptions about information resource support is particularly relevant when a system is safety critical that is when interaction failure consequences could be dangerous, or walk-up-and-use where interaction failure may lead to reluctance to use with expensive consequences. The paper shows that expressing these resource constraints still provides a wider set of behaviours than would occur in practice. A resource may be more or less salient at a particular stage of the interaction and as a result potentially overlooked. For example, the resource may be accessible but not used because it does not seem relevant to the current goal. The paper describes how the resource framework can be augmented with additional information about the salience of the assumed resources. A medical device that is in common use in many hospitals is used as illustration

Modeling Operator Behavior in the Safety Analysis of Collaborative Robotic Applications

Human-Robot Collaboration is increasingly prominent in peo- ple's lives and in the industrial domain, for example in manufacturing applications. The close proximity and frequent physical contacts between humans and robots in such applications make guaranteeing suitable levels of safety for human operators of the utmost importance. Formal veri- cation techniques can help in this regard through the exhaustive explo- ration of system models, which can identify unwanted situations early in the development process. This work extends our SAFER-HRC method- ology with a rich non-deterministic formal model of operator behaviors, which captures the hazardous situations resulting from human errors. The model allows safety engineers to rene their designs until all plausi- ble erroneous behaviors are considered and mitigated

On the Formal Derivation of a FEAL Microprocessor

We present an outline of a method for formal derivation of asynchronous VLSI circuits. The proposed method focuses on transformational style of the design and it uses techniques familiar from the construction of parallel programs. Refinement calculus and action systems are used as a framework for the design process. As a case study we look at the derivation of an asynchronous encryption/decryption microprocessor. 1 Introduction The paper describes ongoing work on exploring a methodology for formal derivation of asynchronous delay-insensitive VLSI circuits within the refinement calculus and the action system framework. It is aimed to be used in the design of application-specific circuits. The basic idea is to apply techniques familiar from the construction of parallel programs to VLSI design. This approach was originally taken by Martin [9] who has developed a methodology for designing asynchronous VLSI circuits as concurrent programs within the CSP-framework. Using his method he has ..

Specification of a Program Derivation Editor

In this paper, a tool for structuring and manipulating formal program derivations is specified using the Z notation. A program derivation style based on (transitive) relations between programs, as found in the refinement calculus, is assumed. The structuring and manipulation of derivations is based on the notion of refinement diagrams proposed by Back. This allows for a style of derivation that is much more flexible than top-down refinement and is more suited to large-scale program development. The original refinement diagram notion is also extended with ideas from window inference which provides a powerful way of dealing with the use of different relations in sub-derivations

Australian and Filipino students’ approaches to learning, conceptions of learning, and learner self-concepts : a cross-cultural comparison

. We describe the Refinement Calculator, a tool which support

Throwing a glance at the neural code: rapid information transmission in the visual system

Our visual system can operate at fascinating speeds. Psychophysical experiments teach us that the processing of complex natural images and visual object recognition require a mere split second. Even in everyday life, our gaze seldom rests for long on any particular spot of the visual scene before a sudden movement of the eyes or the head shifts it to a new location. These observations challenge our understanding of how neurons in the visual system of the brain represent, process, and transmit the relevant visual information quickly enough. This article argues that the speed of visual processing provides an adjuvant framework for studying the neural code in the visual system. In the retina, which constitutes the first stage of visual processing, recent experiments have highlighted response features that allow for particularly rapid information transmission. This sets the stage for discussing some of the fundamental questions in the research of neural coding. How do downstream brain regions read out signals from the retina and combine them with intrinsic signals that accompany eye movements? And, how do the neural response features ultimately affect perception and behavior