James L. Alty

Design issues and implementation of internet-based process control systems

Abstract The Internet provides great potential for the high-level control of process plants. Internet-based process control is a new concept which has been received much attention in previous years. However, little work has so far been done aimed at developing systematic design methods for the design of such Internet-based process control systems. In this paper, five essential design issues that arise from web-related features of Internet-based process control have been investigated: requirement specification, architecture selection, web-based interface design, supervision control, and system safety checking. A water tank control system is used to demonstrate our design methodology. Uniquely, video feedback, text-based chatting, and a whiteboard are embedded in the system and shared by multiple communicating users. Virtual supervision parameter control is implemented to overcome the dynamic time delays caused by the Internet traffic. The experimental results show that the Internet-based control system for the water tank can have a similar behaviour to the local control system if properly designed.

Communicating graphical information to blind users using music: the role of context

We describe the design and use of AUDIOGRAPH - a tool for investigating the use of music in the communication of graphical information to blind and partially sighted users. This paper examines the use of the system to communicate complex diagrams and gives some examples of user output. Performance is not as good as expected and it is postulated that context will play an important part in the perception of diagrams communicated using music. A set of experiments are reported which indicate that context does indeed seem to play an important role in assisting meaningful understanding of the diagrams communicated. The implications for using music in auditory interface design are discussed.

When Bugs Sing

In The Songs of Insects, Pierce (1949) described the striped ground cricket, nemobius fasciatus- fasciatus, which chirps at a rate proportional to ambient air temperature. Twenty chirps-per-second tell us it is 31.4°C; sixteen chirps and its 27°C. This is a natural example of an auditory display, a mechanism for communicating data with sound. By applying auditory display techniques to computer programming we have attempted to give the bugs that live in software programs their own songs. We have developed the CAITLIN musical program auralisation system (Vickers & Alty, 2002b) to allow structured musical mappings to be made of the constructs in Pascal programs. Initial experimental evaluation (Vickers & Alty, 2002a, 2002b) showed that subjects could interpret the musical motifs used to represent the various Pascal language constructs. In this paper we describe how the CAITLIN system was used to study the effects of musical program auralisation on debugging tasks performed by novice Pascal programmers. The results of the experiment indicate that a formal musical framework can act as a medium for communicating information about program behaviour, and that the information communicated could be used to assist with the task of locating bugs in faulty programs.

Development of a distributed simulator for control experiments through the Internet

Abstract The concept of a university campus is changing due to the introduction of distance learning. Although web-based distance learning has been used for various disciplines, web-based experiments are still unusual. A web-based distributed simulator can be a powerful tool for distance learning and a good alternative for web-based control experiments. This paper discusses the design issues of a web-based distributed simulator for control experiments through the Internet, including architecture selection, communication protocol, interface design and process modelling. An industrial catalytic reactor process is used as a case study to illustrate the methods described here. The simulator allows students situated in geographically diverse locations to experiment simultaneously with some aspects of operating the industrial process, and therefore their teamwork skill is developed.

A framework for engineering metaphor at the user interface

Abstract Interface metaphors facilitate the learning of new computer systems by supporting the transformation of existing knowledge in order to improve the comprehension of novel situations. However, there is very little guidance for software designers on how to select, implement and evaluate interface metaphors. This paper, which is based upon extensive work in developing metaphors for telecommunications systems, provides a framework for software designers who wish to exploit the use of interface metaphors. The paper proposes a set of six design steps, to provide designers with a practical approach to the application of metaphor in the design of interactive systems. An explanation of the activities required in each step is given and justified from experience gained in developing a number of interface metaphors. A pragmatic model of the use of metaphor in human centred system design is introduced, and a technique for eliciting metaphor characteristics is developed from ethnomethodology. The approach has been discussed with software designers at two workshops, and the final content has been influenced by their input.

The Use of Music in a Graphical Interface for the Visually Impaired

The possibility of using music to communicate information of a spatial nature to visually impaired users is explored. The development of a tool — the AUDIOGRAPH — which enables visually impaired users to appreciate and manipulate objects contained in a graphical area is described. Early results show that the musical metaphors used did successfully communicate the general spatial layout and the types of objects contained in the space. Music was also successfully used to control the interface.

Musical program auralization: Empirical studies

Program auralization aims to communicate information about program state, data, and behavior using audio. We have argued that music offers many advantages as a communication medium [Alty 1995]. The CAITLIN system [Alty and Vickers 1997; Vickers 1999; Vickers and Alty 1996, 1998] was constructed to provide auralizations within a formal structured musical framework. Pilot studies [Alty and Vickers 1997; Vickers 1999] showed that programmers could infer program structure from auralizations alone. A study was conducted using 22 novice programmers to assess (i) whether novices could understand the musical auralizations and (ii) whether the musical experience and knowledge of subjects affected their performance. The results show that novices could interpret the auralizations (with accuracy varying across different levels of abstraction) and that musical knowledge had no significant effect on performance. A second experiment was conducted with another 22 novice programmers to study the effects of musical program auralization on debugging tasks. The experiment aimed to determine whether auralizations would lead to higher bug detection rates. The results indicate that, in certain circumstances, musical auralizations can be used to help locate bugs in programs and that musical skill does not affect the ability to make use of the auralizations. In addition, the experiment showed that subjective workload increased when the musical auralizations were used.

Using music to communicate computing information

Abstract The audio channel remains little used in most computing applications, often its use being relegated to providing trivial sound effects whose novelty value soon wears off. Nevertheless, in principle sound offers much to the process of human–computer interaction as for most people the notion of auditory imagery is easily accepted. In this paper we explore how sound, specifically musical sound, can be used to communicate computing information. The findings of two studies are presented. The first investigated how pitch intervals and musical phrases of complex (non-sinusoidal) tones can be recognised. The second study aimed to demonstrate that musical structures could communicate information about high-level programming language structures and program run-time behaviour. Both studies showed that music could successfully be used as a communication medium and that listeners did not need to be musically trained to benefit from the audio signals. Finally, recommendations for further work are made.

Siren songs and swan songs debugging with music

Program execution behavior can be mapped to a structured musical framework that helps locate and diagnose software errors.

Adaptive user interface for process control based on multi-agent approach

Teams of operators are required to monitor and control complex real-time processes. Process information comes from different sources and is often displayed by existing User Interfaces using a variety of visual and auditory forms and compressed into narrow time-windows. Most presentation modalities are fixed during interface design and are not capable of adaptation during system operation. The operators alone must provide the flexibility required in order to deal with difficult and unplanned situations. This paper presents an innovative Auto-Adaptive Multimedia Interface (AAMI) architecture, based on Intelligent Agent collaboration, designed to overcome the above drawbacks. The use of this technology should speed up the design and the implementation of human-centred multimedia interfaces, and significantly enhance their usability. The proposed architecture separates generic knowledge about adaptive user interface management from application specific knowledge in order to provide a generic framework suitable to be customised to different application domains. Benefits from the AAMI approach are evaluated by developing two industrial field-test application including Electrical Network Management and Thermal Plant Supervision system. The paper reports the architecture and the basic design principles of the generic framework as well details of the two applications. The work is being carried out within the European ESPRIT project: AMEBICA.