• Radio Resource Management for Satellite UMTS. Dynamic scheduling algorithm for a UMTS-compatible satellite network.

      Hu, Yim Fun; Chan, Pauline M.L.; Min, Geyong; Xu, Kai J. (University of BradfordSchool of Engineering Design and Technology, 2013-11-20)
      The third generation of mobile communication systems introduce interactive Multicast and Unicast multimedia services at a fast data rate of up to 2 Mbps and is expected to complete the globalization of the mobile telecommunication systems. The implementation of these services on satellite systems, particularly for broadcast and multicast applications to complement terrestrial services is ideal since satellite systems are capable of providing global coverage in areas not served by terrestrial telecommunication services. However, the main bottleneck of such systems is the scarcity of radio resources for supporting multimedia applications which has resulted in the rapid growth in research efforts for deriving efficient radio resource management techniques. This issue is addressed in this thesis, where the main emphasis is to design a dynamic scheduling framework and algorithm that can improve the overall performance of the radio resource management strategy of a UMTS compatible satellite network, taking into account the unique characteristics of wireless channel conditions. This thesis will initially be focused on the design of the network and functional architecture of a UMTS -compatible satellite network. Based on this architecture, an effective scheduling framework is designed, which can provide different types of resource assigning strategies. A functional model of scheduler is defined to describe the behaviours and interactions between different functional entities. An OPNET simulation model with a complete network protocol stack is developed to validate the performance of the scheduling algorithms implemented in the satellite network. Different types of traffic are considered for the OPNET simulation, such as the Poisson Process, ONOFF Source and Self Similar Process, so that the performance of scheduling algorithm can be analyzed for different types of services. A novel scheduling algorithm is proposed to optimise the channel utilisation by considering the characteristics of the wireless channel, which are bursty and location dependent. In order to overcome the channel errors, different code rates are applied for the user under different channel conditions. The proposed scheduling algorithm is designed to give higher priority to users with higher code rate, so that the throughput of network is optimized and at the same time, maintaining the end users¿ service level agreements. The fairness of the proposed scheduling algorithm is validated using OPNET simulation. The simulation results show that the algorithm can fairly allocate resource to different connections not only among different service classes but also within the same service class depending on their QoS attributes.
    • Raman spectroscopic application for the analysis of organic compounds and minerals of astrobiological significance. The detection and discrimination of organic compounds and mineral analogues in pure and mixed samples of astrobiological significance using raman spectroscopy, XRD and scanning electron microscopy

      Edwards, Howell G.M.; Scowen, Ian J.; Alajtal, Adel I. (University of BradfordDivision of Chemical and Forensic Sciences, 2010-09-01)
      Raman spectroscopy has been used to characterise both organic and geological samples in order to build a database for the future characterization of biomarker molecules that are of astrobiological relevance. Characteristic geological features and hydrated minerals recently found on the surface of Mars by the NASA planetary rovers Spirit and Opportunity suggest that a possible biosphere could have once existed there. Analytical instrumentation protocols for the unequivocal detection of biomarkers in suitable geological matrices are critical for future unmanned explorations, including the forthcoming ESA ExoMars mission scheduled for 2018. Several geological features found on the surface of Mars by planetary rovers suggest that a possible extinct biosphere could exist based on similar sources of energy as occurred on Earth. For this reason, analytical instrumental protocols for the detection of isolated biomarkers preserved in suitable geological matrices unequivocally and non-destructively have to be evaluated for future unmanned missions. Raman spectroscopy is currently part of the Pasteur instrumentation suite of the ExoMars mission for the remote detection of extant or extinct life signatures in the Martian surface and subsurface. Terrestrial analogues of Martian sites have been identified and the biogeological modifications resulting from extremophilic survival activity have been studied. Here we present the Raman spectral characterization of several examples of organic compounds which have been recorded using 785 nm, 633 nm and 514 nm laser excitation -polycyclic aromatic hydrocarbons (PAHs), organic acids, chlorophyll and carotenoids. Experimental mixtures of ß-carotene in usnic acid, PAHs in usnic acid and PAHs in mineral matrices have also been investigated. Organic compounds and PAHs located under crystalline minerals samples were identified using a 5x objective lens and 785 nm III excitation. The pure compounds and compound mixtures were also analysed using X-ray powder diffraction and scanning electron microscopy (SEM). The results of this study indicate that near infrared laser at 785 nm provided the clearest and the most informative spectra due to the reduction of fluorescence emission. Higher energy lasers operating in the visible region have resulted in the emission of significant background fluorescence. Few samples fluoresce even with the use of 785 nm excitation and FT-Raman spectroscopy remains the instrument of choice for the analysis of these samples.
    • A Raman Spectroscopic Study of Solid Dispersions and Co-crystals During the Pharmaceutical Hot melt Extrusion Process

      Gough, Timothy D.; Paradkar, Anant R.; Banedar, Parineeta N. (University of BradfordCentre for Pharmaceutical Engineering Sciences, Faculty of Life Sciences, 2015)
      Process Analytical Technology (PAT) is framed with the objective of the design and development of processes to ensure predefined quality of the product at the end of manufacturing. PAT implementation includes better understanding of process, reduction in production time with use of in-line, at-line and on-line measurements, yield improvement and energy and cost reductions. Hot Melt Extrusion process (HME) used in the present work is proving increasingly popular in industry for its continuous and green processing which is beneficial over traditional batch processing. The present work was focused on applications of Raman spectroscopy as off - line and in - line monitoring techniques as a PAT for production of pharmaceutical solid dispersions and co-crystals. Solid dispersions (SDs) of the anti-convulsant Carbamazepine (CBZ) with two pharmaceutical grade polymers have been produced using HME at a range of drug loadings and their amorphous nature confirmed using a variety of analytical techniques. Off-line and in-line Raman spectroscopy has been shown to be suitable techniques for proving preparation of these SDs. Through calibration curves generated from chemometric analysis in-line Raman spectroscopy was shown to be more accurate than off-line measurements proving the quantification ability of Raman spectroscopy as well as a PAT tool. Pure co-crystals of Ibuprofen-Nicotinamide and Carbamazepine-Nicotinamide have been produced using solvent evaporation and microwave radiation techniques. Raman spectroscopy proved its superiority over off-line analytical techniques such as DSC, FTIR and XRD for co-crystal purity determination adding to its key advantage in its ability to be used as an in-line, non-destructive technique.
    • The rational design of drug crystals to facilitate particle size reduction. Investigation of crystallisation conditions and crystal properties to enable optimised particle processing and comminution.

      York, Peter; de Matas, Marcel; Blagden, Nicholas; Leusen, Frank J.J.; Shariare, Mohammad H. (University of BradfordSchool of Life Sciences, 2012-02-29)
      Micronisation of active pharmaceutical ingredients (APIs) to achieve desirable quality attributes for formulation preparation and drug delivery remains a major challenge in the pharmaceutical sciences. It is therefore important that the relationships between crystal structure, the mechanical properties of powders and their subsequent influence on processing behaviour are well understood. The aim of this project was therefore to determine the relative importance of particle attributes including size, crystal quality and morphology on processing behaviour and the characteristics of micronised materials. It was then subsequently intended to link this behaviour back to crystal structure and the nature of molecular packing and intermolecular interactions within the crystal lattice enabling the identification of some generic rules which govern the quality of size reduced powders. In this regard, different sieve fractions of lactose monohydrate and crystal variants of ibuprofen and salbutamol sulphate (size, morphology and crystal quality) were investigated in order to determine those factors with greatest impact on post-micronisation measures of particle quality including particle size, degree of crystallinity and surface energy. The results showed that smaller sized feedstock should typically be used to achieve ultrafine powders with high crystallinity. This finding is attributed to the reduced number of fracture events necessary to reduce the size of the particles leading to decreases in milling residence time. However the frequency of crystal cracks is also important, with these imperfections being implicated in crack propagation and brittle fracture. Ibuprofen crystals with a greater number of cracks showed a greater propensity for comminution. Salbutamol sulphate with a high degree of crystal dislocations however gave highly energetic powders, with reduced degree of crystallinity owing to the role dislocations play in facilitating plastic deformation, minimising fragmentation and extending the residence of particles in the microniser. Throughout these studies, morphology was also shown to be critical, with needle like morphology giving increased propensity for size reduction for both ibuprofen and salbutamol sulphate, which is related to the small crack propagation length of these crystals. This behaviour is also attributed to differences in the relative facet areas for the different morphologies of particles, with associated alternative deformation behaviour and slip direction influencing the size reduction process. Molecular modelling demonstrated a general relationship between low energy slip planes, d-spacing and brittleness for a range of materials, with finer particle size distributions achieved for APIs with low value of highest d-spacings for identified slip planes. The highest d-spacing for any material can be readily determined by PXRD (powder x-ray diffraction) which can potentially be used to rank the milling behaviour of pharmaceutical materials and provides a rapid assessment tool to aid process and formulation design. These studies have shown that a range of crystal properties of feedstock can be controlled in order to provide micronised powders with desirable attributes. These include the size, morphology and the density of defects and dislocations in the crystals of the feedstock. Further studies are however required to identify strategies to ensure inter-batch consistency in these attributes following crystallisation of organic molecules.
    • Rationalizing Ethically Questionable Intentions: An Investigation of Marketing Practices in the USA.

      Reast, Jon; Wallace, James; Overall, Jeffrey Scott (University of BradfordSchool of Management, 2014-05-07)
      In this research, a model for ethically questionable decision-making is developed by amalgamating several decision-making theories. The variables of interest are the techniques of neutralization, perceived moral intensity, Machiavellianism, unethical intentions, and ethical judgment. Using a sample of 276 U.S. marketing professionals, partial least squares structural equation modelling was used to validate the model. Findings reveal that U.S. marketing professionals rationalize their ethically questionable intentions through their: (1) perception of moral intensity (i.e., minimizing the harms on others, perceiving their self-interest as most salient, and indifference to social consensus), (2) reliance on various neutralization techniques, and; (3) judgment of their ethically questionable intentions as ethical. After controlling for the Machiavellian personality trait, Machiavellianism did not have a profound effect on the decision-making process, which implies that marketers, in general, are capable of the cognitive distortions found in this study. The main contribution to knowledge is the synthesis of the techniques of neutralization and the perceived moral intensity construct. Through this amalgamation, knowledge of the intermediary steps in the decision-making process has emerged. A contribution to knowledge involves testing the relationship between Machiavellianism and unethical intentions through the mediating variable of the techniques of neutralization. Through this investigation, it was found that the Machiavellian personality is inconsequential to the decision-making process. As a contribution to managerial knowledge, it was found that through cognitive distortions, marketers are capable of various illicit behaviours, which have been shown to be costly to not only stakeholders, but also to the profitability and reputations of organisations.
    • (Re) Visiting Female Entrepreneurs: An Emancipatory Impulse

      Ford, Jackie M.; Larsen, Gretchen; Dean, Hannah (University of BradfordSchool of Management, 2014-12-23)
      This thesis aims to emancipate female entrepreneurs from the metanarrative of economic growth which has created a false dichotomy of successful male entrepreneur versus an unsuccessful female entrepreneur. This aim is pursued through a multidisciplinary and critical inquiry that destabilises this metanarrative conceptually and empirically. A critical interrogation of economic studies reveals the embeddedness of the metanarrative in neo-classical economic growth theory. Far from being a true reflection of the entrepreneurial experience, the theory has silenced the innovator entrepreneur in economic theory and replaced him/her with an economic rational manager. Concurrently, a re-analysis of Schumpeter’s theorising suggests that his theories do not subordinate female entrepreneurs as claimed by a number of critical theorists. In contrast, his theorising is emancipatory and offers an alternative theoretical framework to the oppressive neo-classical economic growth theory. Oral history methods are used to capture the voices of female entrepreneurs which have largely been excluded from the literature. The oral history narratives challenge the oppressive homogeneity imposed by the metanarrative of economic growth and illustrate the negative influence of the theoretical foundation of neo-classical theory upon the entrepreneurial experience. The study offers theoretical, methodological and empirical contributions to female entrepreneurship studies by presenting a fresh interpretation of Schumpeter’s theorising; including the voices of the female entrepreneurs; and applying research approaches that break away from positivism which dominates entrepreneurial studies. The study has implications for policy makers and practitioners as it generates knowledge that takes account of the current social and economic changes.
    • Reaction calorimetry applied to kinetic problems. The design and construction of an isothermal calorimeter with heat compensation by the Peltier effect, and the application of the calorimeter in the study of reaction kinetics in solvent/water mixtures.

      Diaper, John; Canning, R.G. (University of BradfordNot given, 2010-02-11)
      An isothermal calorimeter controlled by the Peltier effect has been designed and constructed in order to investigate reaction rates in solventwater mixtures. Because a thermal method was used a constant temperature environment was essential and this was achieved by using a water bath controlled to + 0.0010C. This callorinieter has been used to study the alkaline hydrolysis of methyl acetate in dimethylsulphoxide, and tetrahydrofuran - water mixtures at 15, 25 and 35 [degrees]C. The results of other investigations on similar reactions have been reviewed and an attempt has been made to correlate the electrostatic theories of Laidler and Eyring, and Amis and jaffe with these results. Finally, because it appears that specific solvent interactions play a major part in the reaction rates the role of water in the reaction mechanism has been examined. A mechanistic explanation has been proposed in order to correlate the rate of reaction with the composition of water-solvent mixtures which justifies the Laidler and Eyring treatment of solvent effects on ion-molecule reactions.
    • Real investment and dividend policy in a dynamic stochastic general equilibrium (DSGE) model. Corporate finance at an aggregate level through DSGE models.

      Freeman, Mark C.; Huang, Shih-Yun (University of BradfordSchool of Management, 2012-06-15)
      In this thesis, I take a theoretical dynamic stochastic general equilibrium (DSGE) approach to investigate optimal aggregate dividend policy. I make the following contribution: 1. I extend the standard DSGE model to incorporate a residual dividend policy, external financing and default and find that simulated optimal aggregate payouts are much more volatile than the observed data when other variables are close to the values observed in the data. 2. I examine the sensitivity of optimal aggregate dividend policy to the level of the representative agent¿s habit motive. My results show that, when the habit motive gets stronger, the volatility of optimal aggregate payouts increases while the volatility of aggregate consumption decreases. This is consistent with the hypothesis that investors use cash payouts from well diversified portfolios to help smooth consumption. 3. I demonstrate that the variability of optimal aggregate payouts is sensitive to capital adjustment costs. My simulated results show that costly frictions from changing the capital base of the firm cause optimal aggregate dividends and real investments to be smooth and share prices to be volatile. This finding is consistent with prior empirical observations. 4. I run simulations that support the hypothesis that optimal aggregate dividend policy is similar when the representative firm is risk averse to when it has capital adjustment costs. In both cases, optimal aggregate dividends volatility is very low. 5. In all calibrated DSGE models, apart from case 4, optimal aggregate payouts are found to be countercyclical. This supports the hypothesis that corporations prefer to hold more free cash flows for potential investment opportunities instead of paying dividends when the economy is booming, but is inconsistent with observed data. Keywords: Dynamic Stochastic General Equilibrium (DSGE), real business cycle, utility function, habits, dividends
    • A real time 3D surface measurement system using projected line patterns.

      Jiang, Ping; Baruch, John E.F.; Shen, Anqi (University of BradfordDepartment of Computing, 2012-03-20)
      This thesis is based on a research project to evaluate a quality control system for car component stamping lines. The quality control system measures the abrasion of the stamping tools by measuring the surface of the products. A 3D vision system is developed for the real time online measurement of the product surface. In this thesis, there are three main research themes. First is to produce an industrial application. All the components of this vision system are selected from industrial products and user application software is developed. A rich human machine interface for interaction with the vision system is developed along with a link between the vision system and a control unit which is established for interaction with a production line. The second research theme is to enhance the robustness of the 3D measurement. As an industrial product, this system will be deployed in different factories. It should be robust against environmental uncertainties. For this purpose, a high signal to noise ratio is required with the light pattern being produced by a laser projector. Additionally, multiple height calculation methods and a spatial Kalman filter are proposed for optimal height estimation. The final research theme is to achieve real time 3D measurement. The vision system is expected to be installed on production lines for online quality inspection. A new 3D measurement method is developed. It combines the spatial binary coded method with phase shift methods with a single image needs to be captured.
    • The realization of signal processing methods and their hardware implementation over multi-carrier modulation using FPGA technology. Validation and implementation of multi-carrier modulation on FPGA, and signal processing of the channel estimation techniques and filter bank architectures for DWT using HDL coding for mobile and wireless applications.

      Abd-Alhameed, Raed A.; Noras, James M.; Migdadi, Hassan S.O. (University of BradfordFaculty of Engineering and Informatics, 2015)
      First part of this thesis presents the design, validation, and implementation of an Orthogonal Frequency Division Multiplexing (OFDM) transmitter and receiver on a Cyclone II FPGA chip using DSP builder and Quartus II high level design tools. The resources in terms of logical elements (LE) including combinational functions and logic registers allocated by the model have been investigated and addressed. The result shows that implementing the basic OFDM transceiver allocates about 14% (equivalent to 6% at transmitter and 8% at receiver) of the available LE resources on an Altera Cyclone II EP2C35F672C6 FPGA chip, largely taken up by the FFT, IFFT and soft decision encoder. Secondly, a new wavelet-based OFDM system based on FDPP-DA based channel estimation is proposed as a reliable ECG Patient Monitoring System, a Personal Wireless telemedicine application. The system performance for different wavelet mothers has been investigated. The effects of AWGN and multipath Rayleigh fading channels have also been studied in the analysis. The performances of FDPP-DA and HDPP-DA-based channel estimations are compared based on both DFT-based OFDM and wavelet-based OFDM systems. The system model was studied using MATLAB software in which the average BER was addressed for randomized data. The main error differences that reflect the quality of the received ECG signals between the reconstructed and original ECG signals are established. Finally a DA-based architecture for 1-D iDWT/DWT based on an OFDM model is implemented for an ECG-PMS wireless telemedicine application. In the portable wireless body transmitter unit at the patient site, a fully Serial-DA-based scheme for iDWT is realized to support higher hardware utilization and lower power consumption; whereas a fully Parallel-DA-based scheme for DWT is applied at the base unit of the hospital site to support a higher throughput. It should be noted that the behavioural level of HDL models of the proposed system was developed and implemented to confirm its correctness in simulation. Then, after the simulation process the design models were synthesised and implemented for the target FPGA to confirm their validation.
    • A reappraisal of archaeological geophysical surveys on Irish road corridors 2001-2010. With particular reference to the influence of geological, seasonal and archaeological variables

      Gaffney, Christopher F.; Armit, Ian; Bonsall, James P.T. (University of BradfordArchaeological and Environmental Science, 2015-07-15)
      Geophysical surveys in the Republic of Ireland and elsewhere rarely have the opportunity to receive direct, meaningful and quantitative feedback from ground observed excavations, despite their frequent occurrence as a subsequent phase of development-led archaeological projects. This research critically reappraises the largest and most coherent geophysical archive maintained by a single end-user over a ten year period. The geophysical archive has been collated from 170 reports on linear road schemes as a result of commercially-driven assessments in Ireland, to facilitate the biggest analysis of geophysical survey legacy data and subsequent detailed excavations. The analysis of the legacy data archive has reviewed and tested the influence of key variables that have, in some circumstances, affected the methods and outcomes of geophysical assessments in Ireland over the last 10 years. By understanding the impact of those key variables upon the legacy data - which include archaeological feature type, geology, sampling strategy and seasonality - appropriate and new ways to research linear corridors have been suggested that should be employed in future geophysical survey assessments for a range of environments and archaeological site types. The comprehensive analysis of geophysical surveys from the legacy data archive has created definitive statements regarding the validity of geophysical techniques in Ireland. Key failures that occurred in the past have been identified and a thorough investigation of new and novel techniques or methods of survey will facilitate a more robust approach to geophysical survey strategies in the future. The outcomes of this research are likely to have ramifications beyond the Irish road corridors from which the legacy data derives.
    • Reconfigurable modelling of physically based systems: Dynamic modelling and optimisation for product design and development applied to the automotive drivetrain system.

      Ebrahimi, Kambiz M.; Mason, Byron A. (University of BradfordSchool of Engineering, Design and Technology, 2009-08-25)
      The work of this thesis is concerned with the aggregation and advancement of modelling practise as used within modern day product development and optimisation environments making use of Model Based Design (¿MBD¿) and similar procedures. A review of model development and use forms the foundation of the work, with the findings being aggregated into two unique approaches for rapid model development and reconfiguration; the Plug-and-Simulate (¿PaS¿) approach and the Paradigm for Large Model Creation (¿PLMC¿); each shown to posses its own advantages. To support the MBD process a model optimisation algorithm that seeks to eliminate parameters that are of little or no significance to a simulation is developed. Eliminations are made on the basis of an energy analysis which determines the activity of a number of energy elements. Low activity elements are said to be of less significance to the global dynamics of a model and thus become targets for elimination. A model configuration tool is presented that brings together the PLMC and parameter elimination algorithm. The tool is shown to be useful for rapid configuration and reconfiguration of models and is capable of automatically running the optimisation algorithms thus producing a simulation model that is parametrically and computationally optimised. The response of the plug-and-simulate drivetrain submodels, assembled to represent a front wheel drive drivetrain, is examined. The resulting model is subjected to a torque step-input and an empirically obtained torque curve that characterises the input to a drivetrain undergoing steady acceleration. The model displays the expected response in both its full parameter and parameter reduced versions with simulation efficiency gains observed in the parameter reduced version.
    • The reconfiguration of the state in an era of neoliberal globalism: State violence and indigenous responses in the Costa Chica-Montaña of Guerrero, Mexico.

      Pearce, Jenny V.; Parra-Rosales, L.P. (University of BradfordDepartment of Peace Studies, 2009-07-31)
      The adoption of the neo-liberal model in the mid-1980s has forced the governing elites to reconfigure the Mexican State. However, the consolidation of a neoliberal State continues to be incomplete and it has been problematic to fully integrated the Mexican economy in the global market due to the increasing organized crime, the dismantling of previous post-revolutionary control mechanisms, and the growing mobilisation of organised indigenous opposition ranging from the peaceful obstruction of hydroelectric mega-projects in their territories to armed struggle. In view of the State crisis, this thesis argues that there has been a shift in the system of control mechanisms of the State that is leaning towards a more recurrent use of open violence to implement its neo-liberal State project. From a theoretical perspective, the research proposes an innovative approach to understanding the formation of the post-revolutionary State, which transcends the State violence dichotomy established between the ´corporatist´ and the ´critical´ approaches in the contemporary literature. The research highlights the wide spectrum of control mechanisms from hegemonic domination to violence used by the governing elites to compensate the unfinished State formation process in order to maintain socio-political stability without profound structural changes. It explores the enhanced tendency of State violence to replace incorporation in Statesociety relations since the efforts to restructure the economy from the 1980s onwards. The thesis analyses how this tendency has grown particularly in response to indigenous movements in the South of Mexico. The argument is substantiated empirically with two case studies undertaken in the sub-region of Costa Chica-Montaña of Guerrero with data from 79 semi-structured interviews with a wide range of social and political actors, and participant observation in ten indigenous communities. The case studies explore the different State control mechanisms used to advance the State formation model in the post revolutionary period; the impact of the crisis of those mechanisms in the sub-region; the violent resistance of local bosses to the loss of power, and the multiples indigenous responses to the implementation of neoliberal policies in their territories. This research also includes a comparative study to explain some factors that strengthen indigenous articulations, as well as their limits in an era of neoliberal globalisation. One of the most important research findings is that neoliberalism has further weakened the ¿civilianisation¿ power of the State to deal peacefully with civil society sectors, particularly with indigenous peoples, while it has strengthened its ¿centralised-coercive¿ power to carry out the imposed State model. Another finding is that the indigenous initiatives that have reinvented themselves through a new version of their practices and broader alliances have consolidated their alternative models. In contrast, the indigenous responses that have reproduced their traditions have failed.
    • Reconstruction of 3D scenes from pairs of uncalibrated images. Creation of an interactive system for extracting 3D data points and investigation of automatic techniques for generating dense 3D data maps from pairs of uncalibrated images for remote sensing applications.

      Ipson, Stanley S.; Qahwaji, Rami S.R.; Alkhadour, Wissam M. (University of BradfordSchool of Computing, Informatics & Media, 2011-07-06)
      Much research effort has been devoted to producing algorithms that contribute directly or indirectly to the extraction of 3D information from a wide variety of types of scenes and conditions of image capture. The research work presented in this thesis is aimed at three distinct applications in this area: interactively extracting 3D points from a pair of uncalibrated images in a flexible way; finding corresponding points automatically in high resolution images, particularly those of archaeological scenes captured from a freely moving light aircraft; and improving a correlation approach to dense disparity mapping leading to 3D surface reconstructions. The fundamental concepts required to describe the principles of stereo vision, the camera models, and the epipolar geometry described by the fundamental matrix are introduced, followed by a detailed literature review of existing methods. An interactive system for viewing a scene via a monochrome or colour anaglyph is presented which allows the user to choose the level of compromise between amount of colour and ghosting perceived by controlling colour saturation, and to choose the depth plane of interest. An improved method of extracting 3D coordinates from disparity values when there is significant error is presented. Interactive methods, while very flexible, require significant effort from the user finding and fusing corresponding points and the thesis continues by presenting several variants of existing scale invariant feature transform methods to automatically find correspondences in uncalibrated high resolution aerial images with improved speed and memory requirements. In addition, a contribution to estimating lens distortion correction by a Levenberg Marquard based method is presented; generating data strings for straight lines which are essential input for estimating lens distortion correction. The remainder of the thesis presents correlation based methods for generating dense disparity maps based on single and multiple image rectifications using sets of automatically found correspondences and demonstrates improvements obtained using the latter method. Some example views of point clouds for 3D surfaces produced from pairs of uncalibrated images using the methods presented in the thesis are included.
    • Reducing Client-Server Communication for Efficient Real-Time Web Applications: The Use of Adaptive Polling as A Case Study for Multi-User Web Applications

      Ridley, Mick J.; Cullen, Andrea J.; Aziz, Hatem M.
      A key challenge of current multi-user web applications is to provide users with interesting events and information in real-time. This research reviews the most common real-time web techniques to identify drawbacks while exploring solutions to improve simplicity, efficiency, and compatibility within a client-server environment. Two solutions are proposed for enhancing the efficiency of real-time web techniques by reducing client-server communication. First, a model of browser monitoring control observes the browser activity and decides if to postpone client-server communication in the case of inactive tabs. This model was implemented and tested with results demonstrating that a significant number of client-server connections can be avoided in the browser background. These results suggest the solution can be optimised for any real-time technique as it benefits from being a developer side technique that works consistently on all browsers. Second, ‘Adaptive Polling’ is a pull-based real-time web technique to overcome bandwidth issues of the reverse AJAX method of ‘Polling’ by controlling the frequency of requesting updates from the server based on the last server response. This approach is implemented and tested with results showing how a significant number of redundant connections can be avoided while the server does not return updates. This solution is a good alternative to other real-time web techniques as it features low latency, the simplicity of implementation, and compatibility with all browsers and servers.
    • Referrals from Primary Eye Care: An Investigation into their quality, levels of false positives and psychological effect on patients.

      Elliott, David B.; Harley, Clare; Green, Clare; Davey, Christopher J. (University of BradfordBradford School of Optometry and Vision Science, 2013-05-02)
      Previous research into the accuracy of referrals for glaucoma has shown that a large number of referrals to the Hospital Eye Service are false positive. Research in areas of healthcare other than ophthalmology has shown that psychological distress can be caused by false positive referrals. The present study aimed to evaluate the quality of referrals to the HES for all ocular pathologies, and also to quantify the proportion of these referrals that were false positive. Any commonality between false positive referrals was investigated. The psychological effect of being referred to the HES was also evaluated using the Hospital Anxiety and Depression Scale (HADS) and State-Trait Anxiety Inventory (STAI). Both scales were validated in this population with Rasch analysis before use. A final aim was to develop an improvement to the present referral pathway in order to reduce numbers of false positive referrals. The accuracy of referrals to the HES appears to improve as clinicians become more experienced, and greater numbers of false positive referrals are generated by female clinicians. Optometrists refer patients with a wide range of ocular diseases and in most cases include both fundus observations and visual acuity measurements in their referrals. GPs mainly refer patients with anterior segment disorders, particularly lid lesions, based on direct observation and symptoms. Illegibility and missing clinical information reduce the quality of many optometric referrals. Patients referred to the HES experience raised levels of anxiety as measured by the STAI and raised levels of depression as measured by the HADS-Depression subscale. As a method of assessing psychological distress, the questionnaires HADS-T (all items), STAI-S (State subscale) and STAI-T (Trait subscale) show good discrimination between patients when administered to a population of new ophthalmic outpatients, despite all having a floor effect. Subsequently a referral refinement service was developed which reduced numbers of unnecessary referrals and reduced costs for the NHS.
    • Refractive error, ocular biometry and oculomotor function: The prevalence of myopia and its potential risk factors in the Middle East, with an investigation of dynamic accommodation responses and axial length fluctuations in young myopic adults.

      Mallen, Edward A.H.; Barrett, Brendan T.; Douthwaite, William A.; Gammoh, Yazan S.S. (University of BradfordOptometry and Vision Science, Bradford School of Life Sciences,, 2012-02-10)
      The main experimental work of this thesis has been a cross-sectional study of the prevalence of refractive error and its biometric correlates in Middle Eastern adults. In addition dynamic accommodative responses and twenty-four hour axial length fluctuations were investigated in young myopic adults. The prevalence of myopia in 3000 Middle Eastern adults (age range 17-40 years) was similar to previously reported levels of myopia in the West. Myopia was associated with a higher level of education, occupations with a high nearwork demand and positive family history of myopia; all of which have been identified as risk factors for myopia development and progression Diurnal variations in axial length (AL) of similar magnitude to those previously reported in emmetropes were observed in myopes recruited in the current thesis. However, the pattern of the diurnal variation in AL was significantly different between early-onset myopes (EOMs) and late-onset myopes (LOMs). There were no significant differences between EOMs and LOMs in the dynamic accommodative response to a sinusoidally oscillating target. The accommodative phase lag was increased following 30 minute adaptation to myopic defocus using +2.00 D lens. However, intense prolonged (30 minute) nearwork was found to have no effect on accommodative gain or phase lag. A number of recommendations for further work on the prevalence of refractive error in the Middle East are suggested along with further research on diurnal AL variations and dynamic accommodative responses in EOMs and LOMs.
    • Reframing the Neolithic

      Not named; Spicer, Nigel Christopher (University of BradfordDepartment of Archaeological Sciences, 2013)
      In advancing a critical examination of post-processualism, the thesis has – as its central aim – the repositioning of the Neolithic within contemporary archaeological theory. Whilst acknowledging the insights it brings to an understanding of the period, it is argued that the knowledge it produces is necessarily constrained by the emphasis it accords to the cultural. Thus, in terms of the transition, the symbolic reading of agriculture to construct a metanarrative of Mesolithic continuity is challenged through a consideration of the evidential base and the indications it gives for a corresponding movement at the level of the economy; whilst the limiting effects generated by an interpretative reading of its monuments for an understanding of the social are considered. Underpinning these constraints is the conceptual privileging of the individual consequent upon the post-processual reaction to the totalising frameworks of modernist knowledge and the metanarratives of progress they construct – as exemplified in the economic reading of Childe. In examining the form of this reaction, the wider post-processual transposition of postmodernism within contemporary archaeological theory is also considered. In utilising Giddens’ concept of reflexivity, it is argued that rather than the ‘cultural turn’ itself, it is the inflection of the epistemological frameworks of the Enlightenment with a teleological reading of the past as progress that represents the postmodern within contemporary archaeological theory and it is through this understanding of postmodernism as expressing the capacity that modernity has to be self-aware that the conditions are established for the recovery of the Neolithic as a holistic object.
    • Regulatory Structures and Bank –Level Risk Management in Ghanaian Banks

      Agyei-Ampomah, S.; Sharma, Abhijit; Akbar, S.; Sasraku, Francis M. (University of BradfordFaculty of Management and Law, 2015)
      This research examines the impact of certain bank-specific variables on bank stability in Ghana, in the context of the existing regulatory structures. The thesis examines this issue along two main themes. The first part of this study examines whether two of the commonly used measures of banking stability, the CAMELS and the Z-Score, provide similar or different results in assessing the stability of banks in Ghana. The results of this study show that the use of the CAMELS and the Z-score measures could lead to different outcomes in terms of bank stability in Ghana. This suggests that the traditional micro-prudential CAMELS framework should be complemented with the Z-score which inherently has both micro and macro-prudential characteristics of signaling weaknesses in bank stability, and to enhance the management of bank stability. The second part of the study examines the impact of some bank-specific variables on bank stability. Using the panel data approach, the results show that while bank size, regulatory governance, regulatory independence and origin impact significantly on the stability score, there was no significant impact in terms of interbank borrowing and non-performing loans. Further analysis using the Blinder –Oaxaca decomposition also suggests that foreign banks in Ghana exhibit relatively higher levels of stability compared to local banks. The policy implications of these findings suggest that the liberalisation of the banking sector should be accompanied by an effective micro- and macro-prudential supervisory regime in order to manage the stability of the constituent banks and the banking sector as a whole.