Jet Noise Receptivity to Nozzle-upstream Perturbations in Compressible Heated Jets

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97078/1/AIAA2012-2259.pd

Computing normalisers of intransitive groups

Funding: The first and third authors would like to thank the Isaac Newton Institute for Mathematical Sciences, Cambridge, for support and hospitality during the programme “Groups, Representations and Applications: New perspectives”, where work on this paper was undertaken. This work was supported by EPSRC grant no EP/R014604/1. This work was also partially supported by a grant from the Simons Foundation. The first and second authors are supported by the Royal Society (RGF\EA\181005 and URF\R\180015).The normaliser problem takes as input subgroups G and H of the symmetric group Sn, and asks one to compute NG(H). The fastest known algorithm for this problem is simply exponential, whilst more efficient algorithms are known for restricted classes of groups. In this paper, we will focus on groups with many orbits. We give a new algorithm for the normaliser problem for these groups that performs many orders of magnitude faster than previous implementations in GAP. We also prove that the normaliser problem for the special case G=Sn  is at least as hard as computing the group of monomial automorphisms of a linear code over any field of fixed prime order.Publisher PDFPeer reviewe

Third Way Environmentalism

This paper is explaining the important design phases of dimensioning an unmanned conventional aircraft from scratch and will also design one according to a few chosen requirements. The design phases discussed will be all from wing dimensioning to stability and spin recovery, aircraft performance requirements and how to select a motor which overcomes these. As well as the optimal rate of climb for improved efficiency is discussed. In the end an aircraft which manages the set requirements and is stable in pitch managing spin recovery with no problem will have been dimensioned

Guest Editors' Introduction

‘I shall have to speak of things, of which I cannot speak’, writes Samuel Beckett in The Unnameable, ‘but also, which is even more interesting, but also that I, which is if possible even more interesting, that I shall have to, I forget, no matter’. Listening to the voice of folly can be like this: an endless flow of inconsistencies, of contradictions, sayings and unsayings; a tantalising, mischievous mockery of speech –unable to go on, unable to end. And yet – as this volume shows – we are irresistibly drawn to folly, its promises, its whispers of ‘even more interesting’ things: of how we are split between conscious and unconscious, familiar and unfamiliar, same and other. For psychoanalysis, folly is not only a site of hidden truths; it is also, perhaps more importantly, a source of unconscious freedom, a momentary escape from our obsession with rules and order. According to Christopher Bollas, the unconscious self is like a fool, who ‘raises potentially endless questions about diverse and disparate issues’ and thereby provides us with a ‘separate sense’, which opens us to others and to our own creative potential. As Rachel Bowlby elegantly puts it, folly is a ‘soul-mole’, forever shovelling our secrets out into the light: ‘there’s no possible moment of release or resignation when the mole might stop vainly, interminably working away’. Folly’s subversive, creative soliloquies reveal to us a psychic ‘underground repertoire of secrets’; they challenge our established knowledge and invite us, as Bolwby shows, to endless, titillating games of ‘suppression and confession’. For Anne Duprat, this deep-seated playfulness explains folly’s close relation to fiction: what makes them so atone is their ‘capacity of creating alternative representations of the world — and thus of re-figuring the world depicted by reason or history – […] but also their paradoxical structure, and hence the instability of their speech acts, which deny, suspend, or do not seriously guarantee the truth of their statements’. (First paragraph