London's spatial economy: the dynamics of change

This 1999 report was commissioned by the London Development Partnership, a body set up to prepare the ground for the Greater London Authority (GLA). It contains the first written proposal for Orbirail, then known as Ringrail and now implemented as the circular element in the Overground - completed on 9 December 2012. That idea had been proposed the previous year in talks by Prof Sir Peter Hall and Drummond Robson at the TCPA to which Michael Edwards contributed. The project was taken up by Nicky Gavron (of LPAC, from 2000 Deputy Mayor of London) and found its way into the London Plan following discussions with DR and Lord Rogers. 1. Infrastructure 1.1 The major likely infrastructure proposals concentrate on improving public transport access in Central London and the corridors east and west of it. 1.2 There is scope to provide significant Inner London improvements largely using existing corridors at lower cost and more quickly than wholly new routes: notably “Ringrail”. This will give rise to interchange and other development opportunities and improve orbital services in Inner London. (There is thus scope for improving public transport access between suburban areas where car-dependence is such a problem). 1.3 A reduced-cost version of Crossrail is possible and should be considered. 1.4 There are few planned road improvements; key ones are likely to be removal of bottlenecks on the primary network, such as the North Circular Road. If these can be designed to favour public transport they could transform accessibility between outer suburbs as the ring rail could closer in. 2. Employment 2.1 Locational choices for employment are excessively restricted or prescribed under current policy which has not kept pace with business practice. 2.2 London’s labour force is highly diverse with a rich range of skills and people are increasingly mobile between jobs. 2.3 Home to work distances have increased as the result of these two forces to the disbenefit of the economy, environment and citizens. 3. Town Centres 3.1 Town centre growth has polarised towards the central and outer areas of London in the last decade or so with declines in the Inner London area where space is short and access deficient. 3.2 The development of retail employment away from Town and Managed Centres is almost entirely of poor quality sheds in a low grade environment, and entirely car dependent. 3.3 PPG6 policies should restrict further Out of Town Centre growth in and around London. Within the framework of these policies there is scope – and an urgent need – to innovate ways which will give centres and local shops a new lease of life and reduce Londoners’ needs to travel

Assessing research impact potential: using the transdisciplinary Outcome Spaces Framework with New Zealand’s National Science Challenges

© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Calls for science to have impact as well as excellence have been loud and clear from research funders, policymakers and research institutions for some time. Transdisciplinary research (TDR) is expected to deliver impact by connecting scientists with stakeholders and end users to co-produce knowledge to respond to complex issues. While New Zealand’s science system is geared to deliver excellence, its capability to also deliver impact beyond academic institutions is less clear. This paper has two interconnected aims. Firstly, it presents findings from testing innovations to the TDR Outcome Spaces Framework (OSF+) with four National Science Challenges (NSCs). We conclude that OSF+ is a useful tool for planning for multiple outcomes and assessing the potential for impact. Secondly, it presents findings of how using OSF+ to assess research impact potential revealed a range of implicit theories of change (i.e. catalyst, deficit, engagement and collaboration) across the NSCs. The findings raise important questions about the prospects for New Zealand’s science system to deliver the envisaged and needed levels of research impact when current institutional settings, expectations, recognition systems, career paths and measures of success are not yet able to adequately accommodate TDR to deliver the research impact

A historic jet-emission minimum reveals hidden spectral features in 3C 273

Aims. The aim of this work is to identify and study spectral features in the quasar 3C 273 usually blended by its strong jet emission. Method. A historic minimum in the sub-millimetre emission of 3C 273 triggered coordinated multi-wavelength observations in June 2004. X-ray observations from the INTEGRAL, XMM-Newton and RXTE satellites are complemented by ground-based optical, infrared, millimetre and radio observations. The overall spectrum is used to model the infrared and X-ray spectral components. Results. Three thermal dust emission components are identified in the infrared. The dust emission on scales from 1 pc to several kpc is comparable to that of other quasars, as expected by AGN unification schemes. The observed weakness of the X-ray emission supports the hypothesis of a synchrotron self-Compton origin for the jet component. There is a clear soft-excess and we find evidence for a very broad iron line which could be emitted in a disk around a Kerr black hole. Other signatures of a Seyfert-like X-ray component are not detected.Comment: 4 pages. Accepted for publication in A&A Letter

Exact Algorithms for Maximum Independent Set

We show that the maximum independent set problem (MIS) on an $n$-vertex graph can be solved in $1.1996^nn^{O(1)}$ time and polynomial space, which even is faster than Robson's $1.2109^{n}n^{O(1)}$-time exponential-space algorithm published in 1986. We also obtain improved algorithms for MIS in graphs with maximum degree 6 and 7, which run in time of $1.1893^nn^{O(1)}$ and $1.1970^nn^{O(1)}$, respectively. Our algorithms are obtained by using fast algorithms for MIS in low-degree graphs in a hierarchical way and making a careful analyses on the structure of bounded-degree graphs

Detection of Cosmic Microwave Background Structure in a Second Field with the Cosmic Anisotropy Telescope

We describe observations at frequencies near 15 GHz of the second 2x2 degree field imaged with the Cambridge Cosmic Anisotropy Telescope (CAT). After the removal of discrete radio sources, structure is detected in the images on characteristic scales of about half a degree, corresponding to spherical harmonic multipoles in the approximate range l= 330--680. A Bayesian analysis confirms that the signal arises predominantly from the cosmic microwave background (CMB) radiation for multipoles in the lower half of this range; the average broad-band power in a bin with centroid l=422 (theta = 51') is estimated to be Delta_T/T=2.1^{+0.4}_{-0.5} x 10^{-5}. For multipoles centred on l=615 (theta =35'), we find contamination from Galactic emission is significant, and constrain the CMB contribution to the measured power in this bin to be Delta_T/T <2.0 x 10^{-5} (1-sigma upper limit). These new results are consistent with the first detection made by CAT in a completely different area of sky. Together with data from other experiments, this new CAT detection adds weight to earlier evidence from CAT for a downturn in the CMB power spectrum on scales smaller than 1 degree. Improved limits on the values of H_0 and Omega are determined using the new CAT data.Comment: 5 pages, 5 figures (gif), submitted to MNRA

Understanding Search Trees via Statistical Physics

We study the random m-ary search tree model (where m stands for the number of branches of a search tree), an important problem for data storage in computer science, using a variety of statistical physics techniques that allow us to obtain exact asymptotic results. In particular, we show that the probability distributions of extreme observables associated with a random search tree such as the height and the balanced height of a tree have a traveling front structure. In addition, the variance of the number of nodes needed to store a data string of a given size N is shown to undergo a striking phase transition at a critical value of the branching ratio m_c=26. We identify the mechanism of this phase transition, show that it is generic and occurs in various other problems as well. New results are obtained when each element of the data string is a D-dimensional vector. We show that this problem also has a phase transition at a critical dimension, D_c= \pi/\sin^{-1}(1/\sqrt{8})=8.69363...Comment: 11 pages, 8 .eps figures included. Invited contribution to STATPHYS-22 held at Bangalore (India) in July 2004. To appear in the proceedings of STATPHYS-2

Unraveling of free carrier absorption for terahertz radiation in heterostructures

The relation between free carrier absorption and intersubband transitions in semiconductor heterostructures is resolved by comparing a sequence of structures. Our numerical and analytical results show how free carrier absorption evolves from the intersubband transitions in the limit of an infinite number of wells with vanishing barrier width. It is explicitly shown that the integral of the absorption over frequency matches the value obtained by the f-sum rule. This shows that a proper treatment of intersubband transitions is fully sufficient to simulate the entire electronic absorption in heterostructure THz devices.Comment: 6 pages, accepted by Physical Review