Turbulence forecasting

In order to forecast turbulence, one needs to have an understanding of the cause of turbulence. Therefore, an attempt is made to show the atmospheric structure that often results when aircraft encounter moderate or greater turbulence. The analysis is based on thousands of hours of observations of flights over the past 39 years of aviation meteorology

Airline meteorological requirements

A brief review of airline meteorological/flight planning is presented. The effects of variations in meteorological parameters upon flight and operational costs are reviewed. Flight path planning through the use of meteorological information is briefly discussed

An improved Ant Colony System for the Sequential Ordering Problem

It is not rare that the performance of one metaheuristic algorithm can be improved by incorporating ideas taken from another. In this article we present how Simulated Annealing (SA) can be used to improve the efficiency of the Ant Colony System (ACS) and Enhanced ACS when solving the Sequential Ordering Problem (SOP). Moreover, we show how the very same ideas can be applied to improve the convergence of a dedicated local search, i.e. the SOP-3-exchange algorithm. A statistical analysis of the proposed algorithms both in terms of finding suitable parameter values and the quality of the generated solutions is presented based on a series of computational experiments conducted on SOP instances from the well-known TSPLIB and SOPLIB2006 repositories. The proposed ACS-SA and EACS-SA algorithms often generate solutions of better quality than the ACS and EACS, respectively. Moreover, the EACS-SA algorithm combined with the proposed SOP-3-exchange-SA local search was able to find 10 new best solutions for the SOP instances from the SOPLIB2006 repository, thus improving the state-of-the-art results as known from the literature. Overall, the best known or improved solutions were found in 41 out of 48 cases.Comment: 30 pages, 8 tables, 11 figure

Discrete local altitude sensing device Patent

Device for use in descending spacecraft as altitude sensor for actuating deceleration retrorocket

Coloniality and the Politicisation of Literary Heritage Conservation

In his autobiography The Life and Rhymes of Benjamin Zephaniah, the dub poet reflects on the relationship between architecture, the built environment, the writing process, and the politics that underpin them. In particular, he notes the impact of colonial legacies in urban planning, his experience as patron of the Ujima Housing Co-operative Group, and the inspiration gained from the diversity of the built environment in Newham (where Zephaniah has resided since 1980). This paper uses these reflections as a starting point to explore the politics of literary heritage conservation in Britain and the colonialism implicit within it. There has been a wave of recent interest in the politics underpinning literary production in the UK sparked by Bernardine Evaristo’s ‘Black Britain, Writing Back’ campaign to correct ‘historical bias in publishing’ and the colonial legacies that foster it. However, far less attention has been paid to the politics behind the conservation of literary heritage. A 2020 report by the National Trust pointed to the role played by ‘conserved’ writers’ houses, such as Bateman’s, Shaw’s Corner, and Monk’s House, in sparking the republication of previous out of print works by writers. The conservation of literary heritage therefore clearly expresses a cultural power, articulating who is left in, or out, of an ever-changing ‘canon’ while providing access points to the literary legacy of writers. Yet, despite attempts to ‘decolonise’ heritage sites, such as the National Trust’s Colonialism and Historic Slavery Report, there is only limited reflection of the coloniality of the values that underpin what is conserved and how we conserve it. In France, the fact that the renovation of Andre Gide’s house in Cuverville sparked a government heritage conservation debate, while the destruction of James Baldwin’s house in St Paul de Vence (2014) failed to elicit similar protests, has led to a rethinking of the politics that facilitate literary heritage conservation. Yet, in Britain, there has been a significant lack of debate on the legacies of Empire and the destruction of black British writers’ houses. This paper reflects on Toni Morrison’s sense of writing as ‘literary archaeology’ to argue for the conservation of writers’ houses as a form of ‘literary architexture’ utilising the semiotics of lived experience to conserve and interpret writers’ homes. First, it applies this methodology to case studies of writers’ homes to examine the coloniality built into the process of heritage conservation. Noting, for example, that the conservation plans for Bloomsbury Group heritage sites dwell on their networks with white literati while failing to mention the significance of global majority figures like Pat Nelson and Berto Pasuka. Secondly, it asks that we re-examine the coloniality behind heritage conservation to fully explore the power structures that override whose literary heritage is conserved and the consequences of this for future

Radio and X-ray observations of an exceptional radio flare in the extreme z=4.72 blazar GB B1428+4217

We report on the extreme behaviour of the high redshift blazar GB B1428+4217 at z=4.72. A continued programme of radio measurements has revealed an exceptional flare in the lightcurve, with the 15.2 GHz flux density rising by a factor ~3 from ~140 mJy to ~430 mJy in a rest-frame timescale of only ~4 months -- much larger than any previous flares observed in this source. In addition to new measurements of the 1.4-43 GHz radio spectrum we also present the analysis and results of a target-of-opportunity X-ray observation using XMM-Newton, made close to the peak in radio flux. Although the X-ray data do not show a flare in the high energy lightcurve, we are able to confirm the X-ray spectral variability hinted at in previous observations. GB B1428+4217 is one of several high-redshift radio-loud quasars that display a low energy break in the X-ray spectrum, probably due to the presence of excess absorption in the source. X-ray spectral analysis of the latest XMM-Newton data is shown to be consistent with the warm absorption scenario which we have hypothesized previously. Warm absorption is also consistent with the observed X-ray spectral variability of the source, in which the spectral changes can be successfully accounted-for with a fixed column density of material in which the ionization state is correlated with hardness of the underlying power-law emission.Comment: 8 pages, 5 figures, MNRAS accepte