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Describes a new reliable low‐cost ultrasonic ranging system to assist in steering a powered wheelchair. Detection algorithms have been created and implemented on a micro controller based stand‐alone system suitable for a tele‐operated vehicle. The detection uses the gradient of the echo envelope and is resistant to noise and inconsistencies in the detection circuitry. The sensor array was considered as separate sensors, working independently so the system could quickly gather separate sets of range information. These sets were overlaid on to a 2D grid array. The new system is cheaper and simpler than available systems for powered wheelchairs.

This paper presents new prototype powered wheelchair systems that are easy to use and safe. The systems use simple ultrasonic sensor systems to assist users in steering their powered wheelchairs. The new systems could improve the chances of some disabled children learning that behaviour and interaction with the environment can be controlled. An overview of the benefits to be offered by an automated wheelchair is included. Some results, problems and difficulties are described along with an assessment of the current position and the way forward.

The purpose of this paper is to investigate how to make tele‐operated tasks easier using an expert system to interpret joystick and sensor data.

Current tele‐operated systems tend to rely heavily on visual feedback and experienced operators. Simple expert systems improve the interaction between an operator and a tele‐operated mobile‐robot using ultrasonic sensors. Systems identify potentially hazardous situations and recommend safe courses of action. Because pairs of tests and results took place, it was possible to use a paired‐samples statistical test.

Results are presented from a series of timed tasks completed by tele‐operators using a joystick to control a mobile‐robot via an umbilical cable. Tele‐operators completed tests both with and without sensors and with and without the new expert system and using a recently published system to compare results. The t‐test was used to compare the means of the samples in the results.

Time taken to complete a tele‐operated task with a mobile‐robot partly depends on how a human operator interacts with the mobile‐robot. Information about the environment was restricted and more effective control of the mobile‐robot could have been achieved if more information about the environment had been available, especially in tight spaces. With more information available for analysis, the central processor could have had tighter control of robot movements. Simple joysticks were used for the test and they could be replaced by more complicated haptic devices. Finally, each individual set of tests was not necessarily statistically significant so that caution was required before generalising the results.

The new systems described here consistently performed tasks more quickly than simple tele‐operated systems with or without sensors to assist. The paper also suggests that the amount of sensor support should be varied depending on circumstances. The paired samples test was used because people (tele‐operators) were inherently variable. Pairing removed much of that random variability. When results were analysed using a paired‐samples statistical test then results were statistically significant. The new systems described in this paper were significantly better at p<0.05 (95 per cent probability that this result would not occur by chance alone).

The paper shows that the new system performed every test faster on average than a recently published system used to compare the results.

The purpose of this paper is to investigate how to make powered‐wheelchair driving easier using simple expert systems to interpret joystick and ultrasonic sensor data. The expert systems interpret shaky joystick movement and identify potentially hazardous situations and then recommend safe courses of action.

The way that a human user interacts with a powered‐wheelchair is investigated. Some simple expert systems are presented that interpret hand tremor and provide joystick position signals for an ultrasonic sensor system. Results are presented from a series of timed tasks completed by users using a joystick to control a powered‐wheelchair. Effect on the efficiency of driving a powered‐wheelchair is measured using the times to drive through progressively more complicated courses. Drivers completed tests both with and without sensors and the most recently published systems are used to compare results.

The new expert systems consistently out‐performed the most recently published systems. A minor secondary result was that in simple environments, wheelchair drivers tended to perform better without any sensor system to assist them but in more complicated environments then they performed better with the sensor systems.

The time taken for a powered‐wheelchair to move from one place to another partly depends on how a human user interacts with the powered‐wheelchair. Wheelchair driving relies heavily on visual feedback and the experience of the drivers. Although attempts were made to remove variation in skill levels by using sets of data associated with each driver and then using paired statistical tests on those sets, some variation must still be present.

The paper presents new systems that could allow more people to use powered‐wheelchairs and also suggests that the amount of sensor support should be varied depending on circumstances.

The new systems described in the paper consistently performed driving tasks more quickly than the most recently published systems.

It has often been said that a great part of the strength of Aslib lies in the fact that it brings together those whose experience has been gained in many widely differing fields but who have a common interest in the means by which information may be collected and disseminated to the greatest advantage. Lists of its members have, therefore, a more than ordinary value since they present, in miniature, a cross‐section of institutions and individuals who share this special interest.

THE L.A. Conference can be said to have finished off the summer, albeit somewhat ingloriously. Frankly it was not a very inspiring affair. However the papers and atmosphere are well described in this number by Mr. Jack Dove and in this column we will confine ourself to that excitement‐packed Annual General Meeting which now probably holds the world record for the shortest A.G.M. of a serious professional institution. The opportunity to express an opinion or ask a question on any aspect of the affairs of the library profession comes only once a year, but the only persons who spoke at the Annual General Meeting were the Chairman, the proposer of the Hon. Auditors, the Mayor of somewhere inviting the Association to hold the Conference there next year and a mover of a vote of thanks to something or other. It makes you wonder. After all the past year has not been entirely without interest to librarians. There are some, we know, who are heartily sick of the sound of the word Roberts but is there no one sufficiently moved to express an opinion on the recommendations contained in the report of the Roberts Committee? It is simply astounding that there was not one motion on the agenda on any aspect of that report. At the time that the agenda was prepared, it was not known that there would be a general election immediately after the conference but surely it is important that the profession as a whole should manifest its view of the recommendations of the committee so that the government could prepare legislation which would have our support. Only one of the major political parties has announced in its manifesto to the electorate that legislation will be introduced in a new Parliament to improve the public library service but of course no details of its proposals have been given. We must know that there is no end to the possible stupidities which could be incorporated into an Act—unless all the bodies concerned impress on the Minister the confirmed opinion of their members. The Association of Municipal Corporations and the County Councils Association have not been slow in making their views known. The Library Association Council presented evidence to the Committee which enjoyed (sic) the support of the membership but it cannot be said that the recommendations have the same support. But does anybody care? Apparently not. We shall grumble when new legislation is presented and then spend the rest of our lives blaming “them”. Is it any wonder that in the words of a London Town Clerk, “librarianship is a depressed profession”? Which leads us nicely to that other apparently unimportant event of the past year.

Communications regarding this column should be addressed to Mrs. Cheney, Peabody Library School, Nashville, Tenn. 37203. Mrs. Cheney does not sell the books listed here. They are available through normal trade sources. Mrs. Cheney, being a member of the editorial board of Pierian Press, will not review Pierian Press reference books in this column. Descriptions of Pierian Press reference books will be included elsewhere in this publication.

We investigate discrepancies between willingness to pay (WTP) and willingness to accept (WTA) in the context of a stated choice experiment. Using data on customer preferences for water services where respondents were able to both ‘sell’ and ‘buy’ the choice experiment attributes, we find evidence of non-linearity in the underlying utility function even though the range of attribute levels is relatively small. Our results reveal the presence of significant loss aversion in all the attributes, including price. We find the WTP–WTA schedule to be asymmetric around the current provision level and that the WTP–WTA ratio varies according to the particular provision change under consideration. Such reference point findings are of direct importance for practitioners and decision-makers using choice experiments for economic appraisal such as cost–benefit analysis, where failure to account for non-linearity in welfare estimates may significantly over- or under-state individual's preferences for gains and avoiding losses respectively.

The text of a lecture given by Alan Rusbridger, Editor of The Guardian, to mark the opening of the new facilities for the Department of Journalism at the University of Central Lancashire, Preston. The theme of the lecture is public trust in what journalists write. Argues that, despite the public’s lack of trust in newspapers, they do in fact uncover many truths that business, industry and Government are attempting to conceal. Examples are provided from the energy industry, science and the environment, transport, Home Office and food safety. Describes the important role The Guardian’s Readers’ Editor has had in increasing public trust in the newspaper.

The purpose of this paper is to present a multi‐expert system that can provide designers with suggestions for improvement. The multi‐expert system can analyse a design and provide designers with ideas for changes to designs at an early stage in order to improve assembly later in the manufacturing process.

The whole system consists of four expert systems: computer‐aided design (CAD) expert, automated assembly expert, manual assembly expert and design analysis expert. The design analysis expert includes a sub‐system to collate the information from the assembly experts and to provide costs and advice.

The paper finds that the approach and the systems can reduce manufacturing costs and lead times.

A knowledge‐based reckoning approach to design‐for‐assembly automation is used. The approach and systems can reduce manufacturing costs and lead times. The system can estimate assembly time and cost for manual or automatic assembly and select suitable assembly techniques.

The system can estimate assembly time and cost for manual or automatic assembly and select a suitable assembly technique.

The new system models assembly, product and process design using a natural approach for capturing intelligence. The new approach categorised automated assembly and manual assembly into separate individual experts. Intelligence and knowledge from each is captured and embedded within the individual expert that represented the process. This approach enabled greater flexibility and made the sub‐systems easier to modify, upgrade, extend and reuse.