Partial Matrix Techniques.

Partial matrix techniques are those in which gravity models are fitted to a partially observed matrix of trips and journey costs, and used to infer the trips in the unobserved cells. This paper reviews the theoretical basis from which such techniques have been developed, and demonstrates the need to pay careful attention to the - underlying assumptions, which in effect require that the model be a good fit to be observed data (and also a good 'fit' to the unobserved data). Circumstances are described in which the estimates for the unobserved cells may not be uniquely determined, and the effects of data structure on the reliability of the estimates (assuming these to be unique) are discussed. Ways are suggested in which further theoretical and empirical research might demonstrate whether a given pattern of observations would lead to particularly error-prone estimates

How Can Speech Recognisers Help Applied Research in the Civil Engineering, Transport and Related Industries

BACKGROUND Speech recognition technology is rapidly advancing to the point here it can be usefully applied in a wide range of mtexts. For applications within the SERC Environment Committee's area of interest -civil engineering; construction; building; transport; water resources there are a number of kinds of recording situation in which one needs to keep one's eyes on the situation being studied; or in which the recording conditions (eg moving around with instruments) are unfavourable. The limitations of conventional pen and paper recording for these situations are obvious; and the limitations of hand-held data capture devices are also becoming apparent. Speech is therefore an easier medium to use; and a tape recorder a convenient means of recording the observations. For well defined recording tasks; speech recognisers might be a helpful way of transcribing the record. This seminar was convened to enable those who are potentially interested in such an application of information technology to hear of the latest developnents and assessments of the suitability of the technology

Report on the Workshop held at the University of Leeds on 6 November organised on behalf of the Transport Sub-Committee of the Environment Committee of the Science and Engineering Research Council

The meeting was the second in a series of three; called to review the prospects for future development of the Special Programme in the Application of Information Technology to Transport set up by the Transport Sub-committee of the Science and Engineering Research Council (SERC). The other seminars were: at University College London on Traffic Engineering Applications; held in July 1986; and at the University of Newcastle up Tyne, on Public Transport Information Systems, held in December 1986. The objectives of the workshop were to (i) review current perceptions of and future prospects for the role of expert systems in transport; and (ii) provide such feed-back to the SERC Transport Sub-committee as would assist it in forming a view about future work in this area. (Continues..

Microsimulation of Organised Car Sharing – Model Predications and Policy Implications.

This paper presents the results of a range of tests of organised car sharing schemes. The performance of the schemes is predicted using a sophisticated microsimulation model. A brief resume of the model is followed by a description of the tests and an analysis of their results. Conclusions are drawn on the place of organised car sharing within broader transport policies, the performance of the model when compared to the available empirical data and directions for public research. The tests here presented include: a series of sensitivity analyses; tests of organisational strategies for car sharing schemes; tests of schemes in a variety of locations and at a variety of scales and finally a batch of tests which investigate the effect of major changes in the operating environment of car sharing schemes - changes in the price of fuel and public transport fares and the provision of parking space incentives for car sharers for example

Project Chariot - Phase III: Progress Report

This is a preliminary report and is NOT FOR PUBLICATIONBotanical investigations of the Cape Thompson - Ogotoruk Creek region of northwest Alaska were initiated in May, 1959 by the University of Alaska under contract with the United States Atomic Energy Commission (Contract No. AT (04 -3 ) - 310). The first summer's field work was largely exploratory and descriptive in nature and included a species inventory of the vascular plants, mosses, and lichens; a qualitative description of the main vegetation types in Ogotoruk Valley; and a preliminary mapping of the vegetation types within the valley. The results of the first summer's field work and winter visits have been partially reported in two reports: Ogotoruk Valley Botanical Project, December, 1959 Report, and the Phase II Interim Pinal Report, Ogotoruk Valley Botanical Project, June, 1960. For brevity, these will be referred to as the December, 1959 Botanical Report, and the June, 1960 Botanical Report. Materials reported in these earlier reports will not be repeated in this December, 1960 report. Botanical investigations were continued during the summer and fall of 1960. The objectives of the 1960 field season were as follows: 1. To measure the frequency, cover, and synthetic features of the main vegetation types in Ogotoruk Valley. 2. To establish control vegetation plots in areas outside the potential blast and fallout area and to extend our understanding of the vegetation of the northwestern Alaska Coast. 3. To complete records of species occurrence in the area by continuing plant collections and identifications. 4. To revise and complete the vegetation map of the area. 5. To continue seed germination studies on certain species. 6. To commence palynological studies of bog and lacustrine sediments. 7. To initiate studies on some of the ecological problems in the Ogotoruk Valley area. a. to understand the relationship between permafrost, annual freezing-thawing cycles, and plant distribution. b. to understand the inter-relationships of the activities of the arctic ground squirrel and vegetation in the valley. Preliminary results of the 1960 field work and additional information from the 1959 season are included in this report