Internet search:subdivision-based interactive query expansion and the soft semantic web

The expansion of the Internet has made the task of searching a crucial one. Internet users, however, have to make a great effort in order to formulate a search query that returns the required results. Many methods have been devised to assist in this task by helping the users modify their query to give better results. In this paper we propose an interactive method for query expansion. It is based on the observation that documents are often found to contain terms with high information content, which can summarise their subject matter. We present experimental results, which demonstrate that our approach significantly shortens the time required in order to accomplish a certain task by performing web searches.

Verification of floating point programs

In this thesis we present an approach to automated verification of floating point programs. Existing techniques for automated generation of correctness theorems are extended to produce proof obligations for accuracy guarantees and absence of floating point exceptions. A prototype automated real number theorem prover is presented, demonstrating a novel application of function interval arithmetic in the context of subdivision-based numerical theorem proving. The prototype is tested on correctness theorems for two simple yet nontrivial programs, proving exception freedom and tight accuracy guarantees automatically. The prover demonstrates a novel application of function interval arithmetic in the context of subdivision-based numerical theorem proving. The experiments show how function intervals can be used to combat the information loss problems that limit the applicability of traditional interval arithmetic in the context of hard real number theorem proving.

Varieties of acquired phonological dyslexia

The existence of different varieties of the acquired reading disorder termed "phonological dyslexia" is demonstrated in this thesis. The data are interpreted in terms of an information-processing model of normal reading which postulates autonomous routes for pronouncing lexical and non-lexical items and identifies a number of separable sub-processes within both lexical and non-lexical routes. A case study approach is used and case reports on ten patients who have particular difficulty in processing non-lexical stimuli following cerebral insult are presented, Chapters 1 and 2 describe the theoretical background to the investigation. Cognitive models of reading are examined in Chapter 1 and the theoretical status of the current taxonomy of the acquired dyslexias discussed in relation to the models. In Chapter 2 the symptoms associated with phonological dyslexia are discussed both in terms of the theoretical models and in terms of the cosistency with which they are reported to occur in clinical studies. Published cases of phonological dyslexia are reviewed. Chapter 3 describes the tests administered and the analysis of error responses. The majority of tests require reading aloud of single lexical or non-lexical items and investigate the effect of different variables on reading performance. Chapter 4 contains the case reports. The final chapter summarises the different patterns of reading behaviour observed. The theoretical model predicts the selective impairment of subsystems within the phonological route. The data provide evidence of such selective impairment. It is concluded that there are different varieties of phonological dyslexia corresponding to the different loci of impairment within the phonological route. It is also concluded that the data support the hypothesis that there are two lexical routes. A further subdivision of phonological dyslexia is made on the basis of selective impairment of the direct or lexical-semantic routes.

The relationship of mineralization to petrology at Parys Mountain, Anglesey

The Lower Palaeozoic succession at Parys Mountain overlies a Precambrian basement (the Iona Series). This succession consists of Ordovician slates, overlain by, and in part interbedded with, Ordovician dacitic and rhyolitic volcanics, which in turn are unconformably overlain by Silurian slates. Both basement and Palaeozoic rocks have been deformed during Caledonian and Variscan orogenies. The resultant structure of Parys Mountain is interpreted as an east-north-easterly trending, single syncline overturned to the north. Many primary extrusive characters are retained by the volcanic rocks, despite the high degree of deformation. The lithologies and textures allow subdivision and interpretation of these rocks as dacite, lithic tuff, siliceous sinter, rhyolitic tuff, rhyolitic ignimbrite, rhyolitic tuff-lava, and rhyolitic lava. The results of 61 bulk chemical analyses are interpreted to show that the volcanism was of the orogenic calc-alkaline type from a continental margin/island arc environment. The magmas probably result from either partial melting of the crustal part of the oceanic lithosphere on a Benioff zone, or partial melting of the mantle, above a Benioff zone, under high load pressures and high water pressures. The mineral deposits are largely confined within the volcanic succession though some occur in the Ordovician and Silurian slates near to their contacts with the volcanics. The majority of the deposits form conformable lenses and tabular bodies, with subordinate deposits as veins and stockworks. The ore mineral assemblages are of chalcopyrite, galena, sphalerite, and pyrite. The general paragenetic sequence (73 sections) is pyrite--chalcopyrite--galena-sphalerite. The main mineralization episode is interpreted to be syngenetic, genetically related to the volcanism. The veins and stockworks probably result from Caledonian and Variscan remobilization of the primary mineralization. Trace element analyses (Cu, Zn, Pb, Ni, Co, Cd, Cr, Hg, Ba, Sr), on 350 specimens, detected anomalous concentrations of these elements around the mineralized zones, though some occur where no mineralization was found. The analyses also indicate a close relationship between the mineralization and the volcanic horizons, especially the siliceous sinter.