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

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

Extending JumpProcess.jl for fast point process simulation with time-varying intensities

Point processes model the occurrence of a countable number of random points over some support. They can model diverse phenomena, such as chemical reactions, stock market transactions and social interactions. We show that JumpProcesses.jl is a fast, general-purpose library for simulating point processes. JumpProcesses.jl was first developed for simulating jump processes via stochastic simulation algorithms (SSAs) (including Doob's method, Gillespie's methods, and Kinetic Monte Carlo methods). Historically, jump processes have been developed in the context of dynamical systems to describe dynamics with discrete jumps. In contrast, the development of point processes has been more focused on describing the occurrence of random events. In this paper, we bridge the gap between the treatment of point and jump process simulation. The algorithms previously included in JumpProcesses.jl can be mapped to three general methods developed in statistics for simulating evolutionary point processes. Our comparative exercise revealed that the library initially lacked an efficient algorithm for simulating processes with variable intensity rates. We, therefore, extended JumpProcesses.jl with a new simulation algorithm, Coevolve, that enables the rapid simulation of processes with locally-bounded variable intensity rates. It is now possible to efficiently simulate any point process on the real line with a non-negative, left-continuous, history-adapted and locally bounded intensity rate coupled or not with differential equations. This extension significantly improves the computational performance of JumpProcesses.jl when simulating such processes, enabling it to become one of the few readily available, fast, general-purpose libraries for simulating evolutionary point processes