Chemical structure matching using correlation matrix memories

This paper describes the application of the Relaxation By Elimination (RBE) method to matching the 3D structure of molecules in chemical databases within the frame work of binary correlation matrix memories. The paper illustrates that, when combined with distributed representations, the method maps well onto these networks, allowing high performance implementation in parallel systems. It outlines the motivation, the neural architecture, the RBE method and presents some results of matching small molecules against a database of 100,000 models

Cities as emergent models: the morphological logic of Manhattan and Barcelona

This paper is set to unveil several particulars about the logic embedded in the diachronic model of city growth and the rules which govern the emergence of urban spaces. The paper outlines an attempt to detect and define the generative rules of a growing urban structure by means of evaluation techniques. The initial approach in this regards will be to study the evolution of existing urban regions or cities which in our case are Manhattan and Barcelona and investigate the rules and causes of their emergence and growth. The paper will concentrate on the spatial aspect of the generative rules and investigate their behaviour and dimensionality. Several Space Syntax evaluation methods will be implemented to capture the change of spatial configurations within the growing urban structures. In addition, certain spatial elements will be isolated and tested aiming to illustrate their influence on the main spatial structures. Both urban regions were found to be emergent products of a bottom up organic growth mostly distinguished in the vicinities of the first settlements. Despite the imposition of a uniform grid on both cities in later stages of their development these cities managed to deform the regularity in the preplanned grid in an emergent manner to end up with an efficient model embodied in their current spatial arrangement. The paper reveals several consistencies in the spatial morphology of both urban regions and provides explanation of these regularities in an approach to extract the underlying rules which contributed to the growth optimization process

Evidence-based design: theoretical and practical reflections of an emerging approach in office architecture

Evidence-based design is a practice that has emerged only relatively recently, inspired by a growing popularity of evidence-based approaches in other professions such as medicine. It has received greatest attention in design for the health sector, but has received less in office architecture, although this would seem not only to be beneficial for clients, but increasingly important in a changing business environment. This paper outlines the history and origins of evidence-based practice, its influence in the health sector, as well as some of the reasons why it has been found more difficult to apply in office architecture. Based on these theoretical reflections, data and experiences from several research case studies in diverse workplace environments are presented following a three part argument: firstly we show how organisational behaviours may change as a result of an organisation moving into a new building; secondly we argue that not all effects of space on organisations are consistent. Examples of both consistent and inconsistent results are presented, giving possible reasons for differences in outcomes. Thirdly, practical implications of evidence-based design are made and difficulties for evidence-based practice, for example the problem of investment of time, are reflected on. The paper concludes that organisations may be distinguished according to both their spatial and transpatial structure (referring to a concept initially introduced by Hillier and Hanson in their study of societies). This means that evidence-based design in office architecture needs to recognise that it deals with a multiplicity of possible organisational forms, with specific clients requiring case-dependent research and evidence gathering. In this evidence-based design practice differs markedly from evidence-based medicine. Finally, we suggest a framework for systematic review inclusion criteria in the development of Evidence-Based Design as a field of practice. We argue that it is only through the development of an approach tailored to the specific nature of design practice and organisational function that research evidence can properly be brought to bear

Comparative studies of offices pre and post — how changing spatial configurations affect organisational behaviours

Understanding the way in which design interventions in an office affect everyday users, and thus shape organisational behaviour, should be high on the agenda for architects, designers and consultants alike. Surprisingly, this seems rarely to be the case. Here we aim to help close this gap by studying a variety of organisations in depth both before and after an office move from the point of view of design practice. This paper thus aims at understanding how a newly designed office is seen, used and filled with life by staff, so that planners can continuously and systematically reflect on and learn from experience, and create effective and well-used workplaces for the future. The research and reflective practice presented in this paper resulted from a collaboration on 'Effective Workplaces' between The Bartlett School of Graduate Studies at University College London and Spacelab architects. Insights from in-depth case studies conducted over the last four years on various corporate clients in the media sector in the UK will be drawn upon. The studies each compared an organisation before and after it moved into a Spacelab-designed office. Two different lines of argument will be presented: firstly, results of the pre-post comparison of organisations before and after moving into a newly designed space suggest that physical space influences the way in which organisations communicate, interact, and perform in many ways. Secondly, the practical side of evidence-based design will be discussed. It can be seen that designers would do things differently if they had had the specific evidence prior to the design process. At the same time, difficulties arise in conducting 'evidence-based' practice, for example the problem of time in a business environment where designers are often asked to deliver solutions within days or weeks, whereas gaining a good understanding of a complex organisation may take months. These issues will be reflected on. General conclusions on the use and usefulness of Space Syntax in an architectural practice will be drawn

Effective workplaces – bridging the gap between architectural research and design practice.

Architectural researchers and design practitioners mostly segregate in distinct communities with hardly any overlap, collaboration or exchange of ideas. This gap between research and practice leads to a wide-spread ignorance and inability to make practical use of evidence produced by research, resulting too often in poor designs and a self-absorbed research that cannot make a difference to peoples’ everyday lives and spatial experience. In order to bridge the gap between architectural research and design practice, UCL’s Bartlett School of Graduate Studies and Spacelab Ltd. have commited themselves to a Knowledge Transfer Partnership on Effective Workplaces. Ideas and concepts on how to change architectural business to combine research and practice will be presented as well as the first analytical results from this newly started venture

Collisionless heating in capacitive discharges enhanced by dual-frequency excitation

We discuss collisionless electron heating in capacitive discharges excited by a combination of two disparate frequencies. By developing an analytical model, we find, contrary to expectation, that the net heating in this case is much larger than the sum of the effects occurring when the two frequencies act separately. This prediction is substantiated by kinetic simulations, which are also in excellent general quantitative agreement with the model for discharge parameters that are typical of recent experiments

The effect of a mindfulness-based decentering strategy on chocolate craving

According to the elaborated-intrusion theory of desire, strategies that load visual working memory will reduce cravings. According to the grounded cognition theory of desire, cravings will be reduced with mindfulness-based decentering strategies that encourage individuals to see their thoughts as thoughts. However, decentering strategies also tend to load visual working memory making it difficult to test the latter prediction. This study addressed this issue by matching visualization across decentering and guided imagery tasks. Male and female participants (n = 101) underwent a chocolate craving induction before listening to a 4-min audio recording that guided them to (a) decenter from their thoughts and feelings, (b) engage in visualization, or (c) let their mind wander. Participants reported on chocolate craving before and after the craving induction and following the 4-min recording. They also provided retrospective reports of craving during the recording, reported on the extent to which they had adhered to the audio instructions and briefly indicated what they had been thinking about during the recording. Results showed a significant reduction in cravings to baseline following the recording across all three conditions (p < .001), but no significant differences between conditions or in the retrospective reports of craving. There was some evidence to suggest that participants in the mind wandering condition had been thinking about alternate goals, which may have inhibited thoughts about chocolate and been just as effective at reducing craving as the imagery and decentering strategies. Exploratory analyses showed a trend toward decentering being more effective than imagery where participants reported higher task adherence throughout the 4 min (p = .067). This raises the possibility that decentering effects may be improved with better strategy adherence, which might be achieved through practice or increased motivation

The Richard commission and the financing of devolved government : the economics of devolution in Wales: Briefing No. 8

If the Barnett formula is rigorously applied to determine the budget of the Welsh Assembly Government, this will ultimately adversely affect the economy of Wales by limiting the growth in aggregate demand. This effect is reinforced now that population weights determining rises in expenditure in Wales (and Scotland and Northern Ireland) are regularly up-dated. There is some controversy in Wales about whether some form of needs-assessment exercise would favour Wales relative to its current position. What is clear is that the outcome of a rigorous, long term application of the Barnett formula would be a share of UK public expenditures in Wales (and Scotland and Northern Ireland) that was almost certainly below the level that would be dictated by any conventional understanding of 'needs'. The impact of the tax-varying power favoured by the Richard Commission is ambiguous, with the direction of effects dependent on the reaction of the current labour force and potential migrants. If workers insist on full compensation for loss of income to tax through a rise in gross wages a tax rise would lead to an economic contraction. However, if workers value the additional public services financed by the tax rise as equal to their loss of disposable income, this effect can be avoided. Much in other words would depend on how the proceeds of the tax rise were spen

SHEEP: The Search for the High Energy Extragalactic Population

We present the SHEEP survey for serendipitously-detected hard X-ray sources in ASCA GIS images. In a survey area of $\sim 40$ deg$^{2}$, 69 sources were detected in the 5-10 keV band to a limiting flux of $\sim 10^{-13}$ erg cm$^{-2}$ s$^{-1}$. The number counts agree with those obtained by the similar BeppoSAX HELLAS survey, and both are in close agreement with ASCA and BeppoSAX 2-10 keV surveys. Spectral analysis of the SHEEP sample reveals that the 2-10 and 5-10 keV surveys do not sample the same populations, however, as we find considerably harder spectra, with an average $\Gamma\sim1.0$ assuming no absorption. The implication is that the agreement in the number counts is coincidental, with the 5-10 keV surveys gaining approximately as many hard sources as they lose soft ones, when compared to the 2-10 keV surveys. This is hard to reconcile with standard AGN ``population synthesis'' models for the X-ray background, which posit the existence of a large population of absorbed sources. We find no evidence of the population hardening at faint fluxes, with the exception that the few very brightest objects are anomalously soft. 53 of the SHEEP sources have been covered by ROSAT in the pointed phase. Of these 32 were detected. An additional 3 were detected in the RASS. As expected the sources detected with ROSAT are systematically softer than those detected with ASCA alone, and of the sample as a whole (truncated).Comment: 36 pages, 7 figs, to appear in Ap

The use of satellites in non-goestationary orbits for unloading geostationary communication satellite traffic peaks. Volume 2: Technical report

The part of the geostationary (GEO) orbital arc used for United States domestic fixed, communications service is rapidly becoming filled with satellites. One of the factors currently limiting its utilization is that communications satellites must be designed to have sufficient capacity to handle peak traffic leads, and thus are under utilized most of the time. A solution is to use satellites in suitable non-geostationary orbits to unload the traffic peaks. Three different designs for a non-geostationary orbit communications satellite system are presented for the 1995 time frame. The economic performance is analyzed and compared with geostationary satellites for two classes of service, trunking and customer premise service. The result is that the larger payload of the non-geostationary satellite offsets the burdens of increased complexity and worse radiation environment to give improved economic performance. Depending on ground terminal configuration, the improved economic performance of the space segment may be offset by increased ground terminal expenses