Hierarchical word clustering - automatic thesaurus generation

In this paper, we propose a hierarchical, lexical clustering neural network algorithm that automatically generates a thesaurus (synonym abstraction) using purely stochastic information derived from unstructured text corpora and requiring no prior word classifications. The lexical hierarchy overcomes the Vocabulary Problem by accommodating paraphrasing through using synonym clusters and overcomes Information Overload by focusing search within cohesive clusters. We describe existing word categorisation methodologies, identifying their respective strengths and weaknesses and evaluate our proposed approach against an existing neural approach using a benchmark statistical approach and a human generated thesaurus for comparison. We also evaluate our word context vector generation methodology against two similar approaches to investigate the effect of word vector dimensionality and the effect of the number of words in the context window on the quality of word clusters produced. We demonstrate the effectiveness of our approach and its superiority to existing techniques. (C) 2002 Elsevier Science B.V. All rights reserved

A high performance k-NN approach using binary neural networks

This paper evaluates a novel k-nearest neighbour (k-NN) classifier built from binary neural networks. The binary neural approach uses robust encoding to map standard ordinal, categorical and numeric data sets onto a binary neural network. The binary neural network uses high speed pattern matching to recall a candidate set of matching records, which are then processed by a conventional k-NN approach to determine the k-best matches. We compare various configurations of the binary approach to a conventional approach for memory overheads, training speed, retrieval speed and retrieval accuracy. We demonstrate the superior performance with respect to speed and memory requirements of the binary approach compared to the standard approach and we pinpoint the optimal configurations. (C) 2003 Elsevier Ltd. All rights reserved

Improved AURA k-Nearest Neighbour approach

The k-Nearest Neighbour (kNN) approach is a widely-used technique for pattern classification. Ranked distance measurements to a known sample set determine the classification of unknown samples. Though effective, kNN, like most classification methods does not scale well with increased sample size. This is due to their being a relationship between the unknown query and every other sample in the data space. In order to make this operation scalable, we apply AURA to the kNN problem. AURA is a highly-scalable associative-memory based binary neural-network intended for high-speed approximate search and match operations on large unstructured datasets. Previous work has seen AURA methods applied to this problem as a scalable, but approximate kNN classifier. This paper continues this work by using AURA in conjunction with kernel-based input vectors, in order to create a fast scalable kNN classifier, whilst improving recall accuracy to levels similar to standard kNN implementations

Vacuum Photon Splitting in Lorentz-Violating Quantum Electrodynamics

Radiative corrections arising from Lorentz violation in the fermion sector induce a nonzero amplitude for vacuum photon splitting. At one loop, the on-shell amplitude acquires both CPT-even and CPT-odd contributions forbidden in conventional electrodynamics.Comment: 4 pages, minor wording changes, references added, accepted in Physical Review Letter

Katharine Susannah Prichard\u27s Coonardoo : an historical study

The focus of this thesis is Katharine Susannah Prichard\u27s novel, Coonardoo ( 1929), and its capacity to provide a framework for the reconstruction of the historical situation in the North-West region of Western Australia during the period mid-1860s to late 1920s. The thesis has a dual purpose: to contextualise the novel in terms of the historical, political, ideological, and social situation; and to read the novel in ways which reveal its reconstruction of the wider historical context. My approach is a new historicist close reading of the text. Specific events or situations are scrutinised for their power to convey insights into the extra-textual situation. For example, the textualisation of the relationship between the white hero and the Aboriginal heroine leads to an exploration of attitudes to interracial sexual encounters in the period of the novel and in the author\u27s contemporary milieu. Included in this work is an exposition of the various industries which contributed substantially to the economic development of the North-West region. These are treated in some depth in relation to their historical circumstances but with particular reference to textual events and situations. An important area of discussion is the social and economic situation which developed between the European settlers in the North-West and the indigenous population of the region. Particular reference is made to the displacement, subjugation and diaspora of the region\u27s Aboriginal population. The pre-contact cultural and religious practices of the Aborigines of the North-West region, and the extent to which these patterns survived into the author\u27s contemporary period, is investigated in the thesis. An appraisal is made of the author\u27s claim that during her visit to the North-West in 1926, she directly observed the Aboriginal traditional forms represented in Coonardoo. Prichard\u27s own socio-cultural and ideological position is explored in relation to the Aboriginal dimension in the novel. Especially relevant is the author\u27s adherence to the theory of Social Darwinism and to the view, prevalent in her society, that the extinction of the Aborigines was imminent and inevitable. Prichard\u27s novel is the starting point of an investigation into the social, economic and political background of the North-West region during the first sixty years of white settlement. The task of this thesis is to \u27recover\u27 the wider historical situation by reference to documents, journals, memoirs and newspapers of the period

Overcoming systematic global barriers to AT: a new methodology and quickstart testing through a £20m programme

Between March and June 2018, the Global Disability Innovation Hub (GDI) led a consortium tasked by the UK Department for International Development (DfID) with comprehensively scoping the barriers to Assistive Technology (AT) access in order to inform the design of a significant new global programme. This paper summarises the evidence examined in that Scoping Report; presents the methodology it proposed; and shares the early findings for the subsequent £20m funded programme, called ‘AT2030 – Access to Assistive Technology for All’ (www.AT2030.org).The Scoping Report sought to unpick the multi-layered and multi-faceted ways in which economic, social, and political factors interact to create barriers to AT for those who need it the most. The team used a mixed-methods approach which was necessarily flexible and iterative, bringing in expertise from the broad partnership. The data showed that the challenge of AT access represents a complex web of market and system failures, compounded by a lack of participation from AT users, that results in a supply/demand mismatch affecting almost a billion people. This makes AT access one of the most pressing global challenges. Because of poor data on use, need and impact this ‘wicked problem’ is largely hidden from view to all but those facing the daily struggles its absence creates. Yet at an individual, family and community level there is no doubt at all about the implications of lack of access to appropriate AT; isolation, economic and social exclusion, poor physical and mental health, and reduced life expectancy. Our evidence suggests that barriers to AT access are about far more than just cost. Issues such as undeveloped policy frameworks, inefficient or non-existent markets, poorly resourced services, stigma and discrimination all play a role, often with a gender impact. The Scoping Report proposed that the resulting global programme (AT2030) trial strategic interventions based on the principles of: building a global mission-led approach; generating better research and data; piloting market-shaping activity; delivering systems strengthening interventions; harnessing innovation; and building community participating and capacity. Findings from the first ten months of delivery have reinforced and confirmed the need for a mission-led approach to AT, embedded within a normative framework of social development. ‘Amazing early results’1 have resulted in a slightly tightened impact framework (theory of change) along with doubled investment. The programme is still in its early stages, but the working assumption is still that the participation of AT users is a necessary factor in the design of innovative solutions, and moreover that the availability of AT products alone is not sufficient to ‘enable a lifetime of potential’ without a systematic approach to inclusion