Infra-red astronomical photometry : one to twenty microns

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The laser mirror alignment system for the LHCb RICH detectors

The Large Hadron Collider beauty (LHCb) experiment at the Large Hadron Collider (CERN), is the next generation B physics experiment designed to precisely constrain the Cabibbo-Kobayashi-Maskawa (CKM) matrix measurements with unprecedented accuracy, as well as search for new physics. The success of the LHCb experiment relies upon excellent particle identification. The central particle identification detectors for the LHCb experiment are the Ring Imaging Cherenkov (RICH) detectors which are reliant upon their optics being well aligned. The optical specifications for the second RICH detector (RICH2) are for the mirrors to be aligned to within 0.1 mrad so as not to degrade the inherent 0.7 mrad resolution of the detector. As the mirrors move out of alignment over time, the performance of the RICH will deteriorate, unless corrected. This thesis describes the design and characterisation of the Laser Mirror Alignment Monitoring System and its image analysis software for selected mirrors of RICH2. This thesis also describes the results of a unique method of combining data from the Laser Mirror Alignment Monitoring System and Tracking system, to recover the positions of all mirror segments in the RICH2 detector. The laser alignment monitoring system resolution has been measured to be 0.013 mrad for both θy and θx rotations, with a long term stability of 0.014 mrad in θ­­­­y and 0.006 mrad in θx. The resolution of the final mirror alignment procedure using data tracks is 0.18 mrad for θy mirror rotations and 0.12 mrad for θx mirror rotations

Moral Uncertainty and Political Philosophy

This thesis addresses a methodological tendency in political philosophy whereby philosophers develop their ethical views independently of the political realm and then import those views into political argumentation intact, without considering whether this sort of primacy of the ethical is appropriate. Observing that the political is non-accidentally typified by disagreement about all manner of things, including, importantly, the ethical, reveals this to be deeply problematic. Through a discussion of moral epistemology, the thesis aims to show that we should not be certain about our moral beliefs in the face of disagreement, which means in turn that we must alter the way in which we approach political philosophy. It considers two responses to this concern: the Unilateral Solution, which argues that if you have access to the moral facts you may ignore disagreement, and the Pluralist Solution, which argues that moral disagreement ought to be taken seriously and that it is the job of political philosophy to provide a framework in which this disagreement can play out. After arguing that neither of these solutions is satisfactory, the thesis concludes that the moral uncertainty caused by disagreement is unavoidable, and offers some suggestions for how we might practice political philosophy in light of this situation

A natural view of perceptual experience

I offer a novel defence of radically externalist theories of perception, via a strikingly spare and broadly physicalist metaphysics. The core, motivating claim is what I call a natural view of perception, according to which perception involves direct awareness of our environment, such that the phenomenology of experience consists of the worldly things perceived, as they appear to the perspective of the subject. To underpin this natural view, I propose a simple metaphysical picture of perception, which identifies the perceptual experience with the relation of awareness holding between subject and object, a relation that can be described in familiar physical terms as a causal process involving the thing perceived and the perceiver. Distinctively, the simple metaphysical picture has no place for the notion of ‘experiences’ understood as distinctively ‘mental’ states or events internal or otherwise belonging to the subject. Although there is some limited precedent for the simple metaphysical picture of perception, I offer the first detailed argument for its role in underpinning the natural view. The thesis offers new and detailed arguments to show that the simple metaphysical picture can not only account for normal perceptual experiences, but can also accommodate and explain other forms of sensory experience that have widely been considered to undermine the natural view of perception. These ‘problem’ cases include perceptual illusion, hallucination, and the role of memory and beliefs in influencing how things appear perceptually. In all of these cases, the simple metaphysical picture accounts for the phenomenology of the experience purely in terms of awareness of worldly objects, albeit in some cases objects that are not currently present in the subject’s environment. The simple metaphysical picture thus promises to explain not just perceptual experience but phenomenal consciousness more generally. The natural view is explicitly a commitment of some varieties of naïve realism, but I argue that the two theses come apart. For one thing, the simple metaphysical picture offers a solution to hallucination and other ‘problem’ cases quite different to the (chiefly disjunctivist) solutions offered by naïve realists. However, the most striking and novel claim advanced here is that the natural view can be defended without a commitment to realism. In this regard, I cite evidence for the subject-relativity or experience-dependence of certain perceived qualities, notably colour, and show the simple metaphysical picture allows us to square this with the natural view that colours are ‘out there’ in the environment. I discuss the metaphysical implications of rejecting realism while adhering to the simple metaphysical picture, and outline a radical – and radically simple – metaphysics of the world in general that might preserve the natural view and accommodate the simple metaphysical picture of phenomenal consciousness more generally. This metaphysics takes the form of a process monism in which the governing metaphysical structuring principle is one of top-down determination, such that whole processes determine the nature of their constituent parts

The wee country that roared : supporting Open Access in Scotland through institutional repositories

The 2019 CWTS Leiden statistics show 3 Scottish institutions in the Top 10 and 4 in the top 15 in Open Access. This presentation will focus on brief case studies of Scottish institutions and the growth of their institutional repository services as a demonstration of a wider national commitment to Open Access. It will also highlight Scotland’s Open Access journey from 2004 to today through the experience and expertise of these institutions and the support of the Scottish Confederation of University and Research Libraries (SCURL). This journey will include the conditions of their local environments, key drivers and a mix of approaches for success, choice of platform(s) and the challenges, at an institutional level in embedding open repositories. These case studies taken together will demonstrate the drive to ensure Scotland’s research is “Open for All” and further enable the global impact for research undertaken in Scottish institutions

The wee country that rOAred : measuring, supporting and building trust in open access in Scotland through institutional repositories

The 2021 CWTS Leiden rankings show 24 UK institutions in the global Top 10 by percentage of Open Access publications and 25% of those institutions are in Scotland. This presentation will focus on the experience of some of these Scottish institutions and the growth of their institutional repository services as a demonstration of a wider national commitment to Open Access. It will also highlight the growth in Open Access demonstrated by the CWTS rankings and Scotland?s Open Access journey from 2004 to today. This will be done through brief case studies which showcase the experience and expertise of these institutions and the support of the Scottish Confederation of University and Research Libraries (SCURL). It will also highlight the opportunities for national collaboration at a Scottish and UK level set against the context of updated UK open access funder policy and a national assessment exercise (REF2021) which was committed to Open Access.PostprintPublisher PDFPeer reviewe

The Dependence of Growth-Model Results on Proficiency Cut Scores

States participating in the Growth Model Pilot Program reference individual student growth against “proficiency” cut scores that conform with the original No Child Left Behind Act (NCLB). Although achievement results from conventional NCLB models are also cut-score dependent, the functional relationships between cut-score location and growth results are more complex and are not currently well described. We apply cut-score scenarios to longitudinal data to demonstrate the dependence of state- and school-level growth results on cut-score choice. This dependence is examined along three dimensions: 1) rigor, as states set cut scores largely at their discretion, 2) across-grade articulation, as the rigor of proficiency standards may vary across grades, and 3) the time horizon chosen for growth to proficiency. Results show that the selection of plausible alternative cut scores within a growth model can change the percentage of students “on track to proficiency” by more than 20 percentage points and reverse accountability decisions for more than 40% of schools. We contribute a framework for predicting these dependencies, and we argue that the cut-score dependence of large-scale growth statistics must be made transparent, particularly for comparisons of growth results across states

Quantum information processing in continuous time

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 127-138) and index.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Quantum mechanical computers can solve certain problems asymptotically faster than any classical computing device. Several fast quantum algorithms are known, but the nature of quantum speedup is not well understood, and inventing new quantum algorithms seems to be difficult. In this thesis, we explore two approaches to designing quantum algorithms based on continuous-time Hamiltonian dynamics. In quantum computation by adiabatic evolution, the computer is prepared in the known ground state of a simple Hamiltonian, which is slowly modified so that its ground state encodes the solution to a problem. We argue that this approach should be inherently robust against low-temperature thermal noise and certain control errors, and we support this claim using simulations. We then show that any adiabatic algorithm can be implemented in a different way, using only a sequence of measurements of the Hamiltonian. We illustrate how this approach can achieve quadratic speedup for the unstructured search problem. We also demonstrate two examples of quantum speedup by quantum walk, a quantum mechanical analog of random walk. First, we consider the problem of searching a region of space for a marked item. Whereas a classical algorithm for this problem requires time proportional to the number of items regardless of the geometry, we show that a simple quantum walk algorithm can find the marked item quadratically faster for a lattice of dimension greater than four, and almost quadratically faster for a four-dimensional lattice. We also show that by endowing the walk with spin degrees of freedom, the critical dimension can be lowered to two. Second, we construct an oracular problem that a quantum walk can solve exponentially faster than any classical algorithm.(cont.) This constitutes the only known example of exponential quantum speedup not based on the quantum Fourier transform. Finally, we consider bipartite Hamiltonians as a model of quantum channels and study their ability to process information given perfect local control. We show that any interaction can simulate any other at a nonzero rate, and that tensor product Hamiltonians can simulate each other reversibly. We also calculate the optimal asymptotic rate at which certain Hamiltonians can generate entanglement.by Andrew MacGregor Childs.Ph.D