52833794
The Role of Night Vision Equipment in Military Incidents and Accidents
Night vision devices provide enormous benefits. They enable personnel to carry out operations under conditions that would not otherwise be possible. However, these benefits carry considerable risks. For instance, individuals often become over confident about their ability to use image intensification and infrared devices. In consequence, the use of night vision equipment is an increasingly common factor in military incidents and accidents. This paper uses an analysis of incident and accident data to identify requirements for the successful deployment of night vision equipment. It is argued that these applications must be integrated more closely with existing navigational systems. The successful application of this technology also depends upon adequate risk assessment and team-based training.
15495731
The Team-Based Operation of Safety-Critical Programmable Systems in US Commercial Aviation and the UK Maritime Industries
This paper analyzes a range of incidents involving team-based interaction with safety-critical programmable systems. The incidents were submitted to NASA’s Aviation Safety Reporting System (ASRS) and to the UK Marine Accident Investigation Branch (MAIB) between December 2001 and February 2003. Our results show that incidents, which complicated the team-based operation of safety-critical, computer systems in commercial aviation, are now being reported within the UK maritime industry. This reflects the increasing use of programmable navigation and collision avoidance devices both in ferry operations and in commercial fishing. For example, many incidents in both industries now stem from operators making inappropriate assumptions about the likely behavior of co-workers and their programmable systems even though part of their task is to actively monitor those activities. Our results also show that a growing number of incidents are triggered when teams must rapidly reprogram complex, safety-critical systems in response to unpredictable changes in their operational requirements.
5064563
Using "Accident Fault Trees" in Conjunction With Traditional Accident Reports
Accident reports help to ensure that operator ‘error’ and system ’failure’ do not threaten other applications. Unfortunately, a number of usability problems limit the effectiveness of these documents. Each section is, typically, drafted by a different expert; forensic scientists follow metallurgists, human factors experts follow meteorologists. In consequence, it can be difficult for readers to form a coherent account of an accident. This paper argues that fault trees can be used to present a clear and concise overview of major failures. Unfortunately, fault trees have a number of limitations. For instance, they do not represent time. This is significant because temporal properties have a profound impact upon the course of human-machine interaction. Similarly, they do not represent the criticality or severity of a failure. We have, therefore, extended the fault tree notation to represent human-machine interaction during major failures. The resulting Accident Fault Tree diagrams can be used in conjunction with an official accident report to better visualise the course of an accident. The Clapham Junction railway disaster (Department of Transport, 1989) is used to illustrate our argument.
14968728
Using Temporal Logic to Support the Specification and Prototyping of Interactive Control Systems
Abstract Accidents at Flixborough, Seveso, Bhopal, Three Mile Island, Windscale and Chernobyl have led to increasing concern over the safety and reliability of control systems. Human factors specialists have responded to this concern and have proposed a number of techniques which support the operator of such applications. Unfortunately, this work has not been accompanied by the provision of adequate tools which might enable a designer to carry it beyond the “laboratory bench” and on to the “shop floor”. The following paper exploits formal, mathematically based specification techniques to provide such a tool. Previous weaknesses of abstract specifications are identified and resolved. In particular, they have failed to capture the temporal properties which human factors specialists identify as crucial to the success or failure of interactive control systems. They also provide the non-formalist with an extremely poor impression of what it would be to like to interact with potential implementations. Temporal logic avoids these deficiencies. It can make explicit the sequential information which may be implicit within a design. Executable subsets of this formalization support prototyping and this provides a means of assessing the qualitative “look and feel” of potential implementations. A variety of presentation strategies, including structural decomposition and dialogue cycles, have been specified and incorporated directly into prototypes using temporal logic. Prelog, a tool for the Presentation and REndering of LOGic specifications, has been developed and its implementation is described.
47143488
The Evaluation of User Interface Notations
Over the last decade a wide range of graphical, tabular and textual notations have been proposed to support the design of human-computer interfaces. These notations are intended to strip away the clutter of implementation details that frequently obscure interaction properties. Unfortunately, relatively little work has been done to evaluate the usability of these notations for ‘real-world’ interfaces. We have, therefore, conducted an empirical evaluation of the User Action Notation (UAN), State Transition Networks (STN) and temporal logic ‘in the wild’. By this we mean that our subjects were drawn from realistic samples of users and designers. We also presented our subjects with realistic descriptions of two user interfaces. This avoids a weakness of previous investigations that have used ‘toy examples’. The results of our investigation show a strong preference amongst our subjects for the use of natural language descriptions. More surprisingly, our results also suggest a link between the frequency of comprehension errors and positive attitude statements towards particular notations. In other words, our subjects made most errors with the notations that they liked the best. This suggests that while graphical notations, such as state transition networks, have a strong intuitive appeal they may also create significant problems for real-world development tasks.
37787829
The epistemics of accidents
Human intervention has played a critical role in the causes of many major accidents. At Three Mile Island, the operators isolated a reactor from its heat sink. The pilots of the Boeing 737 at Kegworth managed to shut down their one functioning engine. Staff continued to allow trains to deposit passengers in Kings? Cross after the fire had started. In retrospect, it seems impossible to predict all of the ways that human intervention might threaten safety. It is, therefore, important that we learn as much as possible from those accidents that do occur. This task is complicated because conventional accident reports contain many hundreds of pages of prose. They present findings drawn from many different disciplines: metallurgy; systems engineering; human factors; meterology. These findings are, typically, separated into a number of distinct chapters. Each section focuses upon a different aspect of the accident. This makes it difficult for designers to recognize the ways in which operator intervention and system failure combine during major failures. The following pages use formal methods to address these concerns. It is argued that mathematical specification techniques can represent human factors and system failures. Unfortunately, formal methods have not previously been used to analyse the factors that motivate operator intervention. This paper, therefore, argues that epistemic extensions of mathematical notations must be recruited in order to support the formal analysis of major accidents.
17884377
Converse to the Parter-Wiener theorem: The case of non-trees
Through a succession of results, it is known that if the graph of an Hermitian matrix A is a tree and if for some index j, @l@?@s(A)@?@s(A(j)), then there is an index i such that the multiplicity of @l in @s(A(i)) is one more than that in A. We exhibit a converse to this result by showing that it is generally true only for trees. In particular, it is shown that the minimum rank of a positive semidefinite matrix with a given graph G is =
16043224
Journeys in non-classical computation II: initial journeys and waypoints
†University of York, Heslington, York YO1 5DD, UK‡University of the West of England, Frenchay Campus, Coldharbourlane, Bristol BS16 1QY, UK{University of Portsmouth, Buckingham Building, Lion Terrace, Portsmouth PO1 3WE, UK§University of Kent, Canterbury, Kent CT2 7NZ, UKkUniversity of Cambridge, Madingley Road, Cambridge CB3 OHE, UK#University of Exeter, North Cote House, The Queen’s Drive, Exeter E4 4QJ, UK
10157262
Topology-Preserving Smoothing of Vector Fields
Proposes a technique for topology-preserving smoothing of sampled vector fields. The vector field data is first converted into a scalar representation in which time surfaces implicitly exist as level sets. We then locally analyze the dynamic behavior of the level sets by placing geometric primitives in the scalar field and by subsequently distorting these primitives with respect to local variations in this field. From the distorted primitives, we calculate the curvature normal and we use the normal magnitude and its direction to separate distinct flow features. Geometrical and topological considerations are then combined to successively smooth dense flow fields, at the same time retaining their topological structure.
2495230
Timbre interfaces using adjectives and adverbs
How can we provide interfaces to synthesis algorithms that will allow us to manipulate timbre directly, using the same timbre-words that are used by human musicians to communicate about timbre? This paper describes ongoing work that uses machine learning methods (principally genetic algorithms and neural networks) to learn (1) to recognise timbral characteristics of sound and (2) to adjust timbral characteristics of existing synthesized sounds.
30236643
Towards a Prehistory of Evolutionary and Adaptive Computation in Music
A number of systems have been created which apply genetic algorithms, cellular automata, artificial life, agents, and other evolutionary and adaptive computation ideas in the creation of music. The aim of this paper is to examine the context in which such systems arose by looking for features of experimental music which prefigure the ideas used in such systems. A number of ideas are explored: the use of randomness in music, the view of compositions as parameterized systems, the idea of emergent structure in music and the idea of musicians performing the role of reactive agents.