394 research outputs found
‘Large complaints in little papers’ : negotiating Ovidian genealogies of complaint in Drayton's Englands Heroicall Epistles
Taking as its starting point Michael Drayton's reworking of a key Heroidean topos, the heroine's self-conscious reflection on letter-writing as an activity fraught with anxiety, this essay examines the cultural and literary factors that conspire to inhibit or facilitate the emergence of a distinctive feminine epistolary voice in Englands Heroicall Epistles. In particular it seeks to explain how Drayton's female letter-writers manage to negotiate the impediments to self-expression they initially encounter and thus go on to articulate morally and politically incisive forms of complaint. It argues that the participation of Drayton's fictional writers in the authorial business of revising Ovid for an altered historical context plays a crucial role in supporting that process. This allows Drayton's heroines to recover a degree of textual authority through an independent critical engagement, by turns resistant and identificatory, with his Ovidian sources, including the Metamorphoses as well as the Heroides. A comparative analysis of the ways in which intertextual allusions to these sources are deployed by his male and female writers reveals them to be governed by a different dynamic and used for different ends. It is primarily by means of their complex, intersecting dialogues with their male correspondents and with the Ovidian models upon which they draw that Drayton's heroines are able to formulate a compelling counter-perspective on the politics of love and history
Quantum Algorithms for Scientific Computing and Approximate Optimization
Quantum computation appears to offer significant advantages over classical computation and this has generated a tremendous interest in the field. In this thesis we study the application of quantum computers to computational problems in science and engineering, and to combinatorial optimization problems. We outline the results below.
Algorithms for scientific computing require modules, i.e., building blocks, implementing elementary numerical functions that have well-controlled numerical error, are uniformly scalable and reversible, and that can be implemented efficiently. We derive quantum algorithms and circuits for computing square roots, logarithms, and arbitrary fractional powers, and derive worst-case error and cost bounds. We describe a modular approach to quantum algorithm design as a first step towards numerical standards and mathematical libraries for quantum scientific computing.
A fundamental but computationally hard problem in physics is to solve the time-independent Schrödinger equation. This is accomplished by computing the eigenvalues of the corresponding Hamiltonian operator. The eigenvalues describe the different energy levels of a system. The cost of classical deterministic algorithms computing these eigenvalues grows exponentially with the number of system degrees of freedom. The number of degrees of freedom is typically proportional to the number of particles in a physical system. We show an efficient quantum algorithm for approximating a constant number of low-order eigenvalues of a Hamiltonian using a perturbation approach. We apply this algorithm to a special case of the Schrödinger equation and show that our algorithm succeeds with high probability, and has cost that scales polynomially with the number of degrees of freedom and the reciprocal of the desired accuracy. This improves and extends earlier results on quantum algorithms for estimating the ground state energy.
We consider the simulation of quantum mechanical systems on a quantum computer. We show a novel divide and conquer approach for Hamiltonian simulation. Using the Hamiltonian structure, we can obtain faster simulation algorithms. Considering a sum of Hamiltonians we split them into groups, simulate each group separately, and combine the partial results. Simulation is customized to take advantage of the properties of each group, and hence yield refined bounds to the overall simulation cost. We illustrate our results using the electronic structure problem of quantum chemistry, where we obtain significantly improved cost estimates under mild assumptions.
We turn to combinatorial optimization problems. An important open question is whether quantum computers provide advantages for the approximation of classically hard combinatorial problems. A promising recently proposed approach of Farhi et al. is the Quantum Approximate Optimization Algorithm (QAOA). We study the application of QAOA to the Maximum Cut problem, and derive analytic performance bounds for the lowest circuit-depth realization, for both general and special classes of graphs. Along the way, we develop a general procedure for analyzing the performance of QAOA for other problems, and show an example demonstrating the difficulty of obtaining similar results for greater depth.
We show a generalization of QAOA and its application to wider classes of combinatorial optimization problems, in particular, problems with feasibility constraints. We introduce the Quantum Alternating Operator Ansatz, which utilizes more general unitary operators than the original QAOA proposal. Our framework facilitates low-resource implementations for many applications which may be particularly suitable for early quantum computers. We specify design criteria, and develop a set of results and tools for mapping diverse problems to explicit quantum circuits. We derive constructions for several important prototypical problems including Maximum Independent Set, Graph Coloring, and the Traveling Salesman problem, and show appealing resource cost estimates for their implementations
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Divide and conquer approach to quantum Hamiltonian simulation
We show a divide and conquer approach for simulating quantum mechanical systems on quantum computers. We can obtain fast simulation algorithms using Hamiltonian structure. Considering a sum of Hamiltonians we split them into groups, simulate each group separately, and combine the partial results. Simulation is customized to take advantage of the properties of each group, and hence yield refined bounds to the overall simulation cost. We illustrate our results using the electronic structure problem of quantum chemistry, where we obtain significantly improved cost estimates under very mild assumptions
The Idea of North
The idea of the North in Western society has a long and distinguished history. Indeed, the only ‘purely ethnographic treatise that survives from antiquity’ is Tacitus’s Germania, his description of the Germanic peoples (Mellor 1993: 14). Tacitus produced his short treatise as a way of forcing Romans to confront the luxurious decadence that he felt had enveloped and deformed their society. The Germania was a companion piece to the Agricola, the life of the military leader, his father-in-law, Cornelius Julius Agricola, governor of Britain and ‘one of the most successful generals of the Flavian era’ (Mellor 1993: 10). Tacitus was also eager to contrast the hard liberties enjoyed by the barbarian tribes of the north to the soft yoke of servility that the Romans had experienced under the tyranny of Nero, as well as the abstemiousness and carefully regulated sexuality of the Germans and Britons to the disgraceful over-indulgence of the Romans. The North might be primitive and unsophisticated, but it had retained a humanity that the South was in danger of losing. [...
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Marlowe and Nashe
This essay explores the relationship between Christopher Marlowe and Thomas Nashe. There are a number of significant connections between the two writers: although Marlowe is known primarily as a dramatist and Nashe as a “proser,” evidence from the hostile Gabriel Harvey reveals that the two were connected in his mind. Nashe appears to have been eager to represent himself as Marlowe’s literary heir, in part through their joint admiration of Pietro Aretino. Both their names are printed on the title-page of Dido, Queen of Carthage (1594), unusual for drama published at that time. Nashe appears to have known Doctor Faustus, not published until 1604, as annotations in his hand demonstrate, and he may have played some role in the authorship of that play. Nashe pays homage to the dead writer in Nashe’s Lenten Stuff (1599), refiguring the doomed relationship between Hero and Leander narrated in Marlowe’s unfinished poem published posthumously in 1598 in the tale of the love between a red herring and a ling. Through this literary transformation of an Ovidian tale Nashe has fashioned Marlowe in his own image
A Methodology for the Examination of the Effectiveness of Secure Erasure Tools Running On Windows XP - Research in Progress
Currently, there appears to be a lack of academic research in the area of testing the efficacy of secure erasure applications and utilities in regard to the activities of an average user in a home or small business context. This research in progress aims to develop a testing methodology that will provide a forensically sound base for which to analyse these tools. It involves the installation of various Internet related applications (for example browsers, instant messaging software and download clients), and the use of these applications for typical Internet activities (e.g. internet banking, instant messaging, web browsing and other activities that would be conducted by an average user). Following the creation of the simulated history, this paper discusses a practical testing methodology that includes the creation of image files, the allocation of these image files, and the use of forensic tools to examine disk contents before and after the execution of the secure erasure applications on the simulated user history. Additionally, a reporting mechanism has been formulated that will allow test results to be efficiently compiled and compared to form valid conclusions about the effectiveness of each erasure utility on internet history
ZeST-NeRF: Using temporal aggregation for Zero-Shot Temporal NeRFs
In the field of media production, video editing techniques play a pivotal
role. Recent approaches have had great success at performing novel view image
synthesis of static scenes. But adding temporal information adds an extra layer
of complexity. Previous models have focused on implicitly representing static
and dynamic scenes using NeRF. These models achieve impressive results but are
costly at training and inference time. They overfit an MLP to describe the
scene implicitly as a function of position. This paper proposes ZeST-NeRF, a
new approach that can produce temporal NeRFs for new scenes without retraining.
We can accurately reconstruct novel views using multi-view synthesis techniques
and scene flow-field estimation, trained only with unrelated scenes. We
demonstrate how existing state-of-the-art approaches from a range of fields
cannot adequately solve this new task and demonstrate the efficacy of our
solution. The resulting network improves quantitatively by 15% and produces
significantly better visual results.Comment: VUA BMVC 202
Clinical debriefing: TALK© to learn and improve together in healthcare environments
The use of clinical debriefing promotes team reflexivity, aligns with Safety II principles and allows organisation leaders to engage clinicians in collaborative change. There is ample evidence of its benefits regarding patient outcomes and team dynamics. This article introduces TALK©, a practical approach to clinical debriefing which supports an inclusive culture of dialogue and empowers clinicians to act and improve. It is underpinned by well defined values that foster positive communication strategies and continued commitment to patient safety. The TALK© structure consists of four steps: Target, Analysis, Learning and Key actions, which guide individuals in having focussed and constructive conversations with practical outcomes. It enables effective communication across diverse health care professional teams that work together on a regular or occasional basis in any healthcare environment
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