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Nuclear Magnetic Resonance (NMR) imaging, also known as Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic technique used in the medical field for body scanning and is a sensitive method to look at the soft tissue. MRI is also used in the imaging of solids in order to study their internal structure. The non-ionising nature of the radiation used in this imaging technique allows the objects to be scanned frequently. One consequence is the generation of large amounts of data to be processed within given time constraints. Once the data is generated from a scanner, it has to be manipulated to recover the original information in the form of a reconstructed image. The developments in the field of Very Large Scale Integrated (VLSI) circuit design and in computing science in the last two to three decades have made significant contributions to the data processing part of imaging. Avenues have yet to be explored as many of the problems posed by physical systems are complex and are not computable in real time, because of their complexity or technological constraints. The past decade has seen many developments in faster processors, specialised processors and low and high level concurrent and distributed systems. One of the major advances has been the development of the transputer and within the last decade many applications have been implemented on transputer based systems. The objective of this thesis is to present one such application with respect to the image reconstruction problem. Issues addressed are the implementation of the algorithm on a concurrent system, flexibility of the algorithm as a function of computing nodes and the development of multi-dimensional reconstruction. A distributed Radix-2 Fast Fourier Transform has been developed and applied in a transputer based environment to the problem of reconstruction of images generated from a full body Nuclear Magnetic Resonance scanner. A transputer ring network of one host and four slaves was used for the development The algorithm was also tested on a sixteen processor system and the scalability of the algorithm assessed. The reconstruction times and memory usage were measured as functions of processor nodes. It is shown that the performance scales as expected theoretically. The interprocessor communications time on the network was measured and the resulting limitations investigated. The limitations imposed by the algorithm are discussed. The reconstruction algorithm was extended to handle three spatial dimensional data. Two methods were used, a three dimensional reconstruction by stacking of two dimensional slices and a three dimensional Fourier Transform technique. These algorithms were implemented on the multi-transputer systems. The limitations of the methods are discussed and the advantages are presented. Finally, a general overview of the constraints of the reconstruction schemes that were developed is given and methods of removing them are suggested. The problem of slice motion in the form of translation and rotation is discussed with reference to the three dimensional stacking reconstruction. Some methods for solving this problem in the concurrent environment are discussed and techniques for their implementation in the present context suggested. The advances in the practical implementation of three dimensional scanning techniques are discussed and their relevance to the concurrent computer systems and the developed algorithms are presented, along with other developments in the field in of parallel computing.

Figuring Naipaul deals with two issues: the writings of the Trinidad-born V.S. Naipaul and the problematic of postcolonial self-representation. In the literary world and among the reading public Naipaul has gained prominence and notoriety in the last two decades. But the critical response to his work has been essentially from what I call the 'mainstream' perspective. In my first Chapter (Part I) I attempt to map various critical trajectories that emerged from the mainstream perspective in the context of Naipaul criticism. In order to contest the tacit assumptions of the mainstream discourse and to figure the representation of the postcolonial world in Naipaul's work I elaborate the patterns in which they both repeat and suggest a certain kind of collusion between the underlying assumptions of the two discourses (Naipaul's own and that of the mainstream criticism). The body of the thesis (Part II), consisting of eight chapters, is largely devoted to a detailed discussion of various ways in which what I call the Naipaul text constructs the postcolonial situation. This discussion elaborates certain recurring ruses and tropes I locate in the Naipaul text. My argument is that the ruses and tropes the text deploys in figuring the subject of the postcolonial world are deeply problematical in that they implicate the text in the hegemonic grand narrative of imperialism. The operation of these ruses and the pattern they constitute in the text are discussed in each Chapter of Part II. The ruses that the text depends on are mainly two: narrative deferral and the ruse of the gaze. The narrative movement of the Naipaul text, as I will show, drawing on the ruses of deferral and the gaze, has no less an aim than that of the project of self-consolidation. That is, these ruses along with tropes of 'centre', 'origin' and 'wholeness' proclaim in Naipaul's writing a certain desire for self-consolidation and self-unification. Between the desire to 'house the subject' and the celebration of a "home" Naipaul's project suspends the subject of the postcolonial world; these aspects are analysed in Chapters Two and Eight of my thesis respectively. But between these two moments, aspects of the text I attempt to unravel, the Naipaul text scapegoats the postcolonial condition. This scapegoating, I will argue, is a necessary condition for the realisation, for Naipaul, of the project of self-consolidation. This operation of the text is figured in the postcolonial dispatches Naipaul constructs. These dispatches, as I read them from Chapters Three to Seven, shape the postcolonial world in the Naipaul text. Each Chapter focuses upon specific works or groups of works by Naipaul. My analysis also engages with various sources the text relies on to prepare its dispatches. Chapter Nine is basically a critique of Naipaul's conception of 'history'; this critique undertakes to analyse Naipaul's utterances about history in general and his historical narrative, The Loss of El Dorado, in specific. My attempt is to show how various narratives of the Naipaul text represent the subject of the postcolonial world. In the process of unravelling the text I attempt to show how one can dislocate a pattern apparent in a text and celebrated by established opinion. I argue that such dislocations are important for conceiving interventionary critical strategies in the postcolonial situation.

The yield-line theory provides a powerful tool for studying the flexural behavior of reinforced concrete slabs at ultimate load. The ductility of steel reinforcement and the plastic properties of concrete material constitute the basis for this theory. Therefore, the application of yield-line theory depends on full plastic behavior in the slab at failure; thus, the slab is assumed to be under reinforced. Yield lines initiate at locations of maximum stress and with increasing load they propagate to a full yield-line pattern; at this stage the slab is divided into-segments and is subjected to its maximum useful load. However, due to strain hardening effect, the resisting capacity of the slab can support a slight increase in load beyond this point. This will follow in large deflections which ultimately results in the instability and collapse of the slab. Being comparatively small, the strain hardening effect is disregarded in yield-line analysis. This adds to the safety against failure. The type of loading and the boundary condition of the slab have an influence on the yield pattern. The yield-line method of analysis can be applied to rectangular as well as non-rectangular slabs; also, it predicts, with good accuracy, the behavior of slabs at failure. Therefore, it provides a realistic estimate of the safety factor against failure; hence this method leads generally to an economical design. These are some of the main advantages of the yield-line theory over the existing classical elastic methods of analysis.