• Validation of an animal model of cognitive dysfunction associated with schizophrenia. Development and validation of the novel object recognition task using behavioural manipulations and psychotomimetic dosing regimens to induce cognitive deficits of relevance to schizophrenia in hooded-Lister rats.

      Neill, Joanna C.; Grayson, Ben (University of BradfordSchool of Pharmacy, 2012-10-26)
      Phencyclidine (PCP) is a non-competitive NMDA receptor antagonist that has been shown to induce schizophrenia-like psychotic symptoms that are clinically indistinguishable from schizophrenia in patients. When administered to rodents, PCP produces an array of behaviours that are characteristic of schizophrenia. Schizophrenia is associated with continual and treatment resistant cognitive deficits which are now recognised as a core feature of the disease. The aim of the studies reported in chapter 3 were to establish a set of objects with equal preference in the NOR (novel object recognition) test. Furthermore, the inter-trial-interval (ITI) of the NOR test was investigated in an attempt to elucidate the effects of time and location of the rats during the ITI on the cognitive impairments following sub-chronic PCP treatment. The experiments in chapter 4 were designed to compare the performance of male and female rats in the NOR test following treatment with acute d-amphetamine (d-amph), PCP and sub-chronic PCP treatment. In chapter 5, validation of the cognitive deficits induced by sub-chronic PCP treatment was assessed using carefully selected pharmacological agents. The aim of the studies in chapter 6 was to determine the effects of isolation rearing on cognitive performance in the NOR test following increasing ITIs. Additionally, the sensitivity of isolation reared rats compared to social controls following acute administration of PCP and d-amph was assessed using the NOR test. Studies in chapter 8 utilised the 16-holeboard maze to determine the effects of acute treatment with d-amphetamine, PCP and scopolamine on working memory in the rat. NOR is a visual learning and memory test that measures recognition memory which is impaired in patients with schizophrenia. Studies presented in this thesis demonstrate the importance of careful pilot studies when selecting objects for use in the NOR test. Initial studies in sub-chronic PCP (2 mg/kg for 7 days followed by 7 days drug free) treated female hooded-Lister rats revealed a preference of the rats for the wooden cone object; subsequently this object was eliminated from further NOR experiments. Sub-chronic PCP treated rats were found to be highly susceptible to the disruptive influence of distraction during the short 1 min inter-trial-interval (ITI) in the NOR test. These results are consistent with clinical findings of the effects of distraction on cognition in schizophrenia patients. Following the initial validation experiments, a 1 min ITI in the home cage was selected for all subsequent NOR studies. Further experiments provided evidence to confirm that information presented in the acquisition trial is encoded but not retained in the retention trial of the NOR test by IV PCP-treated rats. Male rats were less sensitive to the recognition memory deficits induced by acute treatment with PCP and d-amphetamine compared with females. Following sub-chronic PCP treatment, both males and females showed object recognition deficits, however, the impairments were more robust in female rats. Female rats were therefore selected for all subsequent experiments. Pharmacological validation was carried out using carefully selected agents which were assessed for their ability to restore the sub-chronic PCP induced cognitive deficit in the object recognition test. It was found that the classical antipsychotic agents haloperidol and fluphenazine, the benzodiazepine anxiolytic chlordiazepoxide and the SSRI antidepressant fluoxetine were ineffective. Further studies showed that the atypical antipsychotic agents, clozapine and risperidone, the analeptic agent modafinil, the nAChR full agonist nicotine, and full agonist and positive allosteric modulator of the ¿7 nAChR (PNU-282987 and PNU120596 respectively) reversed the recognition memory deficit induced by sub-chronic PCP treatment in the NOR test. Isolation rearing of rats at weaning is an environmental stressor that has relevance for modelling the symptomatology and pathology of schizophrenia. Isolates had a significantly increased locomotor activity (LMA) response to a novel environment and enhanced sensitivity to time delay-induced recognition memory deficits, compared with their socially reared counterparts. Isolates were less sensitive to an acute PCP-induced recognition memory deficit but more sensitive to an acute d-amphetamine induced recognition memory deficit in the NOR test compared to social controls. Preliminary results from the 16-holeboard maze experiments reveal that acute administration of the mAChR antagonist scopolamine, d-amphetamine, PCP and sub-chronic PCP treatment reduced working memory scores compared to vehicle treated controls. Taken together, these findings suggest that sub-chronic treatment with PCP induces cognitive deficits in behavioural tests of relevance to cognition associated with schizophrenia. This may allow the detection of novel pharmacotherapies to alleviate these cognitive deficits and exploration of the nature of cognitive disturbances in these patients.
    • Validation of Low Resistance Filters for Gas/Vapour Sampling.

      Dennis, John; Heron, Carl P.; El-Khashab, M.I.; Alarfaj, Ayman M.A. (University of BradfordDivision of Archaeological, Geographical and Environmental Sciences School of Life Sciences, 2010-03-10)
      Traditional occupational hygiene assessment of occupational exposures to organic gases and vapours rely on low flow (<200 ml/min) NIOSH sorbent tubes. This work investigates 3M charcoal filter media (JK50 and JK40, 3M, Inc.) for collection and analysis of organic vapours across 0.1 ¿ 5 l/min. To enable this work, a custom exposure facility was constructed and validated within which organic analyte gas/vapour concentrations could be introduced at known concentrations while controlling environmental variables such as temperature and humidity and other variables. This facility enabled experiments designed to investigate collection and desorption efficiencies across a range of sample flow rates, temperature and humidity conditions for both NIOSH sorbent tubes (e.g. SKC tube) and 3M charcoal filter media. As a result of the investigations described in this thesis, the following conclusions are drawn. Performance of the 3M charcoal filter media for collection and desorption efficiencies for loading, storage time, humidity and breakthrough at low flow rates (<0.5 l/min) were found comparable to the SKC sorbent tube. It is concluded that 3M charcoal media (JK50 and JK40) are suitable for sampling and analyses of hydrocarbons at flow rates <0.5 l/min. The collection efficiencies of the 3M charcoal filter media were investigated at high flow rates (>0.5l/min) for the same parameters, i.e., loading, temperature and humidity. It is concluded that 3M charcoal filter media can be used with confidence in sampling and analysis of airborne hydrocarbons up to 5 l/min. The Wheeler-Jonas model was found to satisfactorily predict the adsorption kinetics of the 3M charcoal filter media at different loading values of hydrocarbons. It was therefore concluded that the model can be applied to determine the suitable amount of 3M charcoal filter media prior to sampling for a given loading.
    • Valuing and managing brands: An internal accounting perspective. An empirical investigation of attitudes to internal brand valuation and organisational and behavioural implications associated with the way that the internal brand management accounting system is operated.

      Pike, Richard H.; Guilding, Christopher J. (University of BradfordThe Management Centre, 2009-11-03)
      This thesis is concerned with accounting for the brand management function. Two distinct perspectives are taken: the first derives from aspects of organisational and behavioural accounting research, and the second concerns organisational implications of brand valuation. Both perspectives were initially approached by means of exploratory interviews and a literature review. Hypotheses pertaining to the first perspective were analysed via survey data collected in nine strongly-branded, fast-moving consumer goods (FMCG) companies. Propositions concerned with the implications of brand valuation were developed and used as the basis for measuring attitudes to brand valuation. A questionnaire concerned with brand valuation attitudes was administered to senior-ranking officials in strongly-branded, FMCG companies. The final methodological phase, for both perspectives, involved a case study conducted in a strongly-branded, FMCG company. Significant findings arising from this study include: 1) Managers who see their company as being short-termist, hold more positive attitudes to brand valuation. 2) Marketing-orientated managers are more favourably disposed to brand valuation than accounting-orientated managers. 3) Organisational benefits arising from brand valuation are more strategically, than operationally, orientated. 4) Brand manager budget participation is significantly negatively-related to job-related tension, and positivelyrelated to trust in superior and attitude to reliance on accounting performance measures. 5) Budget participation is more effective in reducing jobrelated tension in situations of high, compared to low, task uncertainty situations. 6) Reliance on a brand manager's accounting performance is positively related to brand manager performance and motivation, and negatively associated with job-related tension.
    • Venous haemodynamic and cerebrospinal fluid anomalies associated with multiple sclerosis

      Not named; Beggs, Clive B. (University of BradfordSchool of Engineering, 2015-07-01)
      This critical synopsis of prior work by Clive Beggs is submitted in support of a PhD by published work. The work focuses on venous and cerebrospinal fluid (CSF) anomalies associated with multiple sclerosis (MS) and other neurological diseases. MS is characterized by focal inflammatory lesions, which are often venocentric. Recently a vascular syndrome, chronic cerebrospinal venous insufficiency (CCSVI) has been linked with MS. This syndrome, which is characterized by constricted cerebral venous outflow, has become mired in controversy, with various studies producing conflicting findings, with the result that the science associated with CCSVI has become obscured. Clive Beggs work seeks to bring clarity to the debate surrounding CCSVI by characterizing physiological changes associated with constricted cerebral venous outflow. The work submitted here involves collaborative studies with Robert Zivadinov (University of Buffalo), Paolo Zamboni (University of Ferrara), and Chih- Ping Chung (National Yang Ming University of Medicine). The key findings of these studies are: (i) MS patients, diagnosed with CCSVI, exhibit greatly increased hydraulic resistance of the cerebral venous drainage system; (ii) MS patients experience loss of the small cerebral veins; (iii) MS patients exhibit reduced CSF bulk flow, consistent with mild venous hypertension; (iv) MS patients exhibit increased CSF pulsatility in the Aqueduct of Sylvius, which appears to be linked with mild venous hypertension associated with CCSVI; and (v) jugular venous reflux is associated with white matter and parenchymal volumetric changes in Alzheimer’s patients. Collectively, these findings suggest that extracranial venous anomalies are associated with changes in the intracranial physiology.
    • Vibrational spectroscopic techniques (Raman, FT-IR and FT-NIR spectroscopy) as a means for the solid-state structural analysis of pharmaceuticals

      Edwards, Howell G.M.; Ali, H.R.H. (University of BradfordSchool of Pharmacy, 2009-08-21)
      The aim of this work was to assess the suitability of vibrational spectroscopic techniques (Raman, FT-IR and FT-NIR spectroscopy) as a means for the solid-state structural analysis of pharmaceuticals. Budesonide, fluticasone propionate, salbutamol hemisulfate, terbutaline hemisulfate, ipratropium bromide, polymorphic forms of salmeterol xinafoate and two polymorphic forms of sulfathiazole were selected since they are used in the management of certain respiratory disorders and from different chemical and pharmacological entities along with some pharmaceutical excipients. Conventional visual examination is not sufficient to identify and differentiate spectra between different pharmaceuticals. To confirm the assignment of key molecular vibrational band signatures, quantum chemical calculations of the vibrational spectra were employed for better understanding of the first five selected drugs. The nondestructive nature of the vibrational spectroscopic techniques and the success of quantum chemical calculations demonstrated in this work have indeed offered a new dimension for the rapid identification and characterisation of pharmaceuticals and essentially warrant further research. The application of simultaneous in situ Raman spectroscopy and differential scanning calorimetry for the preliminary investigation of the polymorphic transformation of salmeterol xinafoate polymorphs and two polymorphic forms of sulfathiazole has also been explored in this work leading to the development of a new method for the solid-state estimation of the transition temperature of entantiotropically related pharmaceutical polymorphs which represents the first analytical record of the use of this approach for pharmaceutical polymorphs.
    • Vibro-acoustic products from re-cycled raw materials using a cold extrusion process. A continuous cold extrusion process has been developed to tailor a porous structure from polymeric waste, so that the final material possesses particular vibro-acoustic properties.

      Horoshenkov, Kirill V.; Benkreira, Hadj; Khan, Amir (University of BradfordSchool of Engineering, Design and Technology., 2010-05-07)
      A cold extrusion process has been developed to tailor a porous structure from polymeric waste. The use of an extruder to manufacture acoustic materials from recycled waste is a novel idea and the author is not aware of any similar attempts. The extruder conveys and mixes the particulates with a reacting binder. The end result is the continuous production of bound particulates through which a controlled amount of carbon dioxide gas that is evolved during the reaction is used to give the desired acoustic properties. The cold extrusion process is a low energy consuming process that reprocesses the post manufacturing waste into new vibro-acoustic products that can be used to meet the growing public expectations for a quieter environment. The acoustical properties of the developed products are modelled using Pade approximation and Johnson-Champoux-Allard models. Applications for the developed products are widespread and include acoustic underlay, insulation and panels in buildings, noise barriers for motorways and railway tracks, acoustic insulation in commercial appliances and transport vehicles.
    • Violent peace in Liberia. A Study of the Roles and Ambitions of Ex-combatants

      Pankhurst, Donna T.; Agoha, Christopher (University of BradfordDepartment of Peace Studies, 2015)
      Liberia emerged from 14 years of brutal civil conflict, demobilized and “reintegrated” large numbers of ex-combatants, but there are still concerns about ex-combatants’ re-engagement in violence. Yet, adequate knowledge and empirical evidence about this are still sketchy. Qualitative fieldwork among ex-combatants conducted in five locations in Monrovia from 2012-2013, suggests that ex-combatants are re-marginalized. This research presents excombatants’ current status, their re-marginalization, and factors indicative of their re-engagement in violence in post-conflict Liberia. The study contends that ex-combatants were apparently not satisfied with the outcome of the DDRR programme, as it failed to reintegrate them successfully. The study developed a four dimensional analytical framework that includes, (a) re-marginalization (b) re-criminalization (c) exploitation, and (d) economic insecurity, which are then applied to the outcome of the reintegration of ex-combatants in Liberia. On the basis of the data collected in fieldwork, the analytical framework reveals how these factors and dynamics interacted and facilitated the occurrence of violence. The study argues that an awareness of ex-combatants’ vulnerability and re-marginalization should put state actors in a position to better predict their violent inclinations. It further notes that ex-combatant re-engagement in violence is largely manifested at the political and economic levels and this has the potential to lead to a renewed conflict if not mitigated. This study by no means completes the tasks of research and analysis on violence and excombatants, but it outlines theoretical propositions and conclusions, which can hopefully spark further debate and collective efforts among researchers to push this field of study forward.
    • Virtual sensor for air mass flow measurement in an SI engine: Application of distributed lumped modelling in prediction of air mass flow into the cylinder of SI combustion engines

      Qi, Hong-Seng; Ebrahimi, Kambiz M.; Filippou, Sotirios
      After undergoing an extensive study about engine air mass flow measurement approaches as well as engine modelling for air mass flow prediction, a major problem found to exist is that engineers have still not found a suitable technique to accurately measure the air mass flow entering the cylinder of an internal combustion engine. The engine air mass flow is the most important parameter needed during engine development so the fuel control can be accurately calibrated and as a result increase performance and reduce emission output of an engine. The current methods used to determine the air mass flow lead to inaccuracies due to the large amount of mathematical assumptions and also sensor errors and as a result the mapping and calibration process of a new engine family takes approximately 2 years due to extensive modelling and testing required overcoming the above drawbacks. To improve this, the distributed lumped modelling technique (D-L) of the inlet manifold was chosen, where the intake system is separated into very small sections which are distributed continuously throughout the volume of the intake until entering the cylinder. This technique is validated against a CFD model of the engine’s intake system and real engine data as well as a 1D engine model.
    • Visual corporate identity and internal customer perceptions : Employee response to corporate colours and symbols in an education environment.

      Trueman, Myfanwy; Fukukawa, Kyoko; Holland, Annabelle J.M. (University of BradfordSchool of Management, 2013-11-20)
      This thesis examines the importance of employee perceptions of their organisation¿s visual corporate identity (VCI) particularly the symbolic ¿corporate logo¿. Employees¿ views of the logo reveal their perceptions of the organisation itself (Henderson and Cote 1998:15, Olins 1995:73) so are an important indicator of their positive or negative feelings towards their establishment. Previous research recognises the significance of employees¿ opinions, but has overlooked their perceptions of the VCI. In education, external marketing (including VCI) is of growing interest but there has been little concern with internal marketing. Methodology A mixed methods, sequential, explanatory case study into a UK independent school was undertaken. Quantitative data was obtained from questionnaires, distributed to the schools¿ employees and qualitative data from interviews; analysis reveals convergent and divergent findings.Findings The majority of the schools¿ employees consider the corporate colours and logo important, associate positive meanings with the logo and were proud to be linked to the school by wearing branded items. Employees felt affiliation for the logo and considered the VCI to be strong although responses differed depending upon gender, full or part-time employment, department, seniority and length-of-service. A new model has been developed, the IMP Test, that reveals the perceptions; the importance, meanings, and pride that employees attach to their VCI. Implications These findings reinforce and add to previous research of employee perceptions of their VCI (particularly in education) and it follows, towards their organisation. Utilising this approach, managers can gain a deeper understanding of employee perceptions which has implications for morale and motivation.
    • Visual Feedback Stabilisation of a Cart Inverted Pendulum A

      Qahwaji, Rami S.R.; Gheorghe, Marian; Hossain, M. Alamgir; Dahal, Keshav P.; Ingram, Stephen D.
      Vision-based object stabilisation is an exciting and challenging area of research, and is one that promises great technical advancements in the field of computer vision. As humans, we are capable of a tremendous array of skilful interactions, particularly when balancing unstable objects that have complex, non-linear dynamics. These complex dynamics impose a difficult control problem, since the object must be stabilised through collaboration between applied forces and vision-based feedback. To coordinate our actions and facilitate delivery of precise amounts of muscle torque, we primarily use our eyes to provide feedback in a closed-loop control scheme. This ability to control an inherently unstable object by vision-only feedback demonstrates an exceptionally high degree of voluntary motor skill. Despite the pervasiveness of vision-based stabilisation in humans and animals, relatively little is known about the neural strategies used to achieve this task. In the last few decades, with advancements in technology, we have tried to impart the skill of vision-based object stabilisation to machines, with varying degrees of success. Within the context of this research, we continue this pursuit by employing the classic Cart Inverted Pendulum; an inherently unstable, non-linear system to investigate dynamic object balancing by vision-only feedback. The Inverted Pendulum is considered to be one of the most fundamental benchmark systems in control theory; as a platform, it provides us with a strong, well established test bed for this research. We seek to discover what strategies are used to stabilise the Cart Inverted Pendulum, and to determine if these strategies can be deployed in Real-Time, using cost-effective solutions. The thesis confronts, and overcomes the problems imposed by low-bandwidth USB cameras; such as poor colour-balance, image noise and low frame rates etc., to successfully achieve vision-based stabilisation. The thesis presents a comprehensive vision-based control system that is capable of balancing an inverted pendulum with a resting oscillation of approximately ±1º. We employ a novel, segment-based location and tracking algorithm, which was found to have excellent noise immunity and enhanced robustness. We successfully demonstrate the resilience of the tracking and pose estimation algorithm against visual disturbances in Real-Time, and with minimal recovery delay. The algorithm was evaluated against peer reviewed research; in terms of processing time, amplitude of oscillation, measurement accuracy and resting oscillation. For each key performance indicator, our system was found to be superior in many cases to that found in the literature. The thesis also delivers a complete test software environment, where vision-based algorithms can be evaluated. This environment includes a flexible tracking model generator to allow customisation of visual markers used by the system. We conclude by successfully performing off-line optimization of our method by means of Artificial Neural Networks, to achieve a significant improvement in angle measurement accuracy.
    • Visual perception of gradients. A psychophysical study of the mechanisms of detection and discrimination of achromatic and chromatic gradients.

      Bloj, Marina; Ruppertsberg, Alexa I.; Garcia-Suarez, Luis (University of BradfordBradford School of Optometry and Vision Science, 2010-06-08)
    • Visual Performance in Pseudophakia. The Effect of Meridional Blur in Pseudoaccommodation.

      Cox, Michael J.; Chisholm, Catharine M.; Serra, Pedro M.F.N. (University of BradfordBradford School of Optometry and Vision Sciences, 2014-05-07)
      The main aim of this thesis is to evaluate the effect of meridional blur, using refractive induced astigmatism, on visual performance at far and close distances. Visual performance was evaluated using letter discrimination tasks at distance and near (visual acuity, VA) and a reading task at near on subjects with pharmacologically blocked (young) or absent accommodation (presbyopic and pseudophakic). The effect of astigmatism was tested using positive cylindrical lenses oriented at 180 and 90 degrees, these simulating with- (WTR) and against-the-rule (ATR) astigmatism. Other refractive status were also evaluated, namely, in-focus and spherical defocus. The visual performance data were correlated with biometric measurements (pupil size, anterior chamber depth (ACD), corneal and ocular aberrations, corneal multifocality, patient age, axial length). Further, the functionality of meridional blur was evaluated for alphabets in addition to the standard Roman alphabet using a VA task. The results confirm that myopic astigmatism contributes to a better visual performance at closer distances, with ATR astigmatism providing higher performance for reading tasks compared to other forms of astigmatism. Anatomical factors such as pupil size, corneal multifocality and ACD were significantly correlated visual performance, while other ocular characteristics were not. Ray tracing modelling using wavefront data was a moderate predictor of VA and reading acuity. The results of the effect of meridional blur orientation on alphabets other than the Roman alphabet, suggest that visual performance is dependent on the interaction between blur orientation and letter¿s spatial characteristics. In conclusion, pseudoaccommodation is a multifactorial phenomenon with pupil size being the major contributor for the improvement in visual performance. Against-the-rule shows advantages over WTR astigmatism, by providing higher reading performance, however extending the present and previous findings for clinical application will require further investigation on the effect of meridional blur in common and socio-culturally adapted tasks.
    • Visuomotor control of step descent : the importance of visual information from the lower visual field in regulating landing control. When descending a step from a stationary standing position or during on-going gait, is online visual information from the lower visual field important in regulating prelanding kinematic and landing mechanic variables?

      Buckley, John G.; Elliott, David B.; Bennett, S.J.; Timmis, Matthew A. (University of BradfordDepartment of Engineering Design and Technology, 2010-09-29)
      The majority of previous research investigating the role of vision in controlling adaptive gait has predominantly focused on over-ground walking or obstacle negotiation. Thus there is a paucity of literature investigating visuomotor control of step descent. This thesis addressed the importance of the lower visual field (lvf) in regulating step descent landing control, and determined when visual feedback is typically used in regulating landing control prior to / during step descent. When step descents were completed from a stationary starting position, with the lvf occluded or degraded, participants adapted their stepping strategy in a manner consistent with being uncertain regarding the precise location of the foot / lower leg relative to the floor. However, these changes in landing control under conditions of lvf occlusion were made without fundamentally altering stepping strategy. This suggests that participants were able to plan the general stepping strategy when only upper visual field cues were available. When lvf was occluded from either 2 or 1 step(s) prior to descending a step during on-going gait, stepping strategy was only affected when the lvf was occluded in the penultimate step. Findings suggest that lvf cues are acquired in the penultimate step / few seconds prior to descent and provide exproprioceptive information of the foot / lower leg relative to the floor which ensures landing is regulated with increased certainty. Findings also highlight the subtle role of online vision used in the latter portion of step descent to 'fine tune' landing control.
    • VM Allocation in Cloud Datacenters Based on the Multi-Agent System. An Investigation into the Design and Response Time Analysis of a Multi-Agent-based Virtual Machine (VM) Allocation/Placement Policy in Cloud Datacenters

      Kouvatsos, Demetres D.; Kiran, Mariam; Al-ou'n, Ashraf M.S. (University of BradfordSchool of Electrical Engineering and Computer Science, Faculty of Engineering and Informatics, 2017)
      Recent years have witnessed a surge in demand for infrastructure and services to cover high demands on processing big chunks of data and applications resulting in a mega Cloud Datacenter. A datacenter is of high complexity with increasing difficulties to identify, allocate efficiently and fast an appropriate host for the requested virtual machine (VM). Establishing a good awareness of all datacenter’s resources enables the allocation “placement” policies to make the best decision in reducing the time that is needed to allocate and create the VM(s) at the appropriate host(s). However, current algorithms and policies of placement “allocation” do not focus efficiently on awareness of the resources of the datacenter, and moreover, they are based on conventional static techniques. Which are adversely impacting on the allocation progress of the policies. This thesis proposes a new Agent-based allocation/placement policy that employs some of the Multi-Agent system features to get a good awareness of Cloud Datacenter resources and also provide an efficient allocation decision for the requested VMs. Specifically, (a) The Multi-Agent concept is used as a part of the placement policy (b) A Contract Net Protocol is devised to establish good awareness and (c) A verification process is developed to fully dimensional VM specifications during allocation. These new results show a reduction in response time of VM allocation and the usage improvement of occupied resources. The proposed Agent-based policy was implemented using the CloudSim toolkit and consequently was compared, based on a series of typical numerical experiments, with the toolkit’s default policy. The comparative study was carried out in terms of the time duration of VM allocation and other aspects such as the number of available VM types and the amount of occupied resources. Moreover, a two-stage comparative study was introduced through this thesis. Firstly, the proposed policy is compared with four state of the art algorithms, namely the Random algorithm and three one-dimensional Bin-Packing algorithms. Secondly, the three Bin-Packing algorithms were enhanced to have a two-dimensional verification structure and were compared against the proposed new algorithm of the Agent-based policy. Following a rigorous comparative study, it was shown that, through the typical numerical experiments of all stages, the proposed new Agent-based policy had superior performance in terms of the allocation times. Finally, avenues arising from this thesis are included.
    • Voluntary disclosure of corporate strategy: determinants and outcomes. An empirical study into the risks and payoffs of communicating corporate strategy.

      Filatotchev, Igor; Coebergh, Henricus P.T. (University of BradfordSchool of Management, 2013-11-21)
      Business leaders increasingly face pressure from stakeholders to be transparent. There appears however little consensus on the risks and payoffs of disclosing vital information such as corporate strategy. To fill this gap, this study analyzes firm-specific determinants and organisational outcomes of voluntary disclosure of corporate strategy. Stakeholder theory and agency theory help to understand whether companies serve their interest to engage with stakeholders and overcome information asymmetries. I connect these theories and propose a comprehensive approach to measure voluntary disclosure of corporate strategy. Hypotheses from the theoretical framework are empirically tested through panel regression of data on identified determinants and outcomes and of disclosed strategy through annual reports, corporate social responsibility reports, corporate websites and corporate press releases by the 70 largest publicly listed companies in the Netherlands from 2003 through 2008. I found that industry, profitability, dual-listing status, national ranking status and listing age have significant effects on voluntary disclosure of corporate strategy. No significant effects are found for size, leverage and ownership concentration. On outcomes, I found that liquidity of stock and corporate reputation are significantly influenced by voluntary disclosure of corporate strategy. No significant effect is found for volatility of stock. My contributions to theory, methodology and empirics offers a stepping-stone for further research into understanding how companies can use transparency to manage stakeholder relations.
    • Vortex of Genocide: Banyamulenge Identity Formation in Pursuit of the Genocidaire, Zaïre (1996- 1997)

      Macaulay, Fiona; Harris, David; Davey, Christopher P.
      Genocide is conventionally seen through the mutually exclusive characterisations of perpetrators and victims. Attempts to understand this phenomenon in the 1990s postcolonial African Great Lakes region suffer from this same limitation. This dissertation critiques the limiting binary of perpetrator and victim identities. By examining the messy formation of identities in genocide, this research demonstrates that the latter are layered and fluid. Using relational sociology, identities are examined through the narrative analysis of interviews with Banyamulenge soldiers who participated in the early 1990s Rwandan Patriotic Front (RPF), and the short-lived Alliance des Forces Démocratiques pour la Libération du Congo (AFDL). These soldiers witnessed first-hand the violence and devastation of the Rwandan civil war and 1994 genocide. The AFDL, under Rwandan leadership, went on to obliterate 233,000 Rwandan refugees spread across Zaïre form 1996 to 1997. A heuristic device of a vortex is used to conceptualise a process of identity formation framed by three features of genocide, namely narratives of insecurity, destructive crises, and intermediate space. RPF and Banyamulenge narratives, power relations, and relational journeys are traced through an exploration of the networks and histories of these features. Banyamulenge soldier identities are formed in movements through this vortex with each experience of genocide. Such movements resulted in violence against the refugees. A specific relation to the idea of the enemy as a guilty genocidaire was constructed through the deployment of multiple narratives. The genocidaire was essential to Banyamulenge identities as they went on to perpetrate genocide against the Rwandan refugees.
    • Vulnerability in online social network profiles. A Framework for Measuring Consequences of Information Disclosure in Online Social Networks.

      Neagu, Daniel; Ridley, Mick J.; Alim, Sophia (University of BradfordDepartment of Computing, 2013-03-05)
      The increase in online social network (OSN) usage has led to personal details known as attributes being readily displayed in OSN profiles. This can lead to the profile owners being vulnerable to privacy and social engineering attacks which include identity theft, stalking and re identification by linking. Due to a need to address privacy in OSNs, this thesis presents a framework to quantify the vulnerability of a user¿s OSN profile. Vulnerability is defined as the likelihood that the personal details displayed on an OSN profile will spread due to the actions of the profile owner and their friends in regards to information disclosure. The vulnerability measure consists of three components. The individual vulnerability is calculated by allocating weights to profile attribute values disclosed and neighbourhood features which may contribute towards the personal vulnerability of the profile user. The relative vulnerability is the collective vulnerability of the profiles¿ friends. The absolute vulnerability is the overall profile vulnerability which considers the individual and relative vulnerabilities. The first part of the framework details a data retrieval approach to extract MySpace profile data to test the vulnerability algorithm using real cases. The profile structure presented significant extraction problems because of the dynamic nature of the OSN. Issues of the usability of a standard dataset including ethical concerns are discussed. Application of the vulnerability measure on extracted data emphasised how so called ¿private profiles¿ are not immune to vulnerability issues. This is because some profile details can still be displayed on private profiles. The second part of the framework presents the normalisation of the measure, in the context of a formal approach which includes the development of axioms and validation of the measure but with a larger dataset of profiles. The axioms highlight that changes in the presented list of profile attributes, and the attributes¿ weights in making the profile vulnerable, affect the individual vulnerability of a profile. iii Validation of the measure showed that vulnerability involving OSN profiles does occur and this provides a good basis for other researchers to build on the measure further. The novelty of this vulnerability measure is that it takes into account not just the attributes presented on each individual profile but features of the profiles¿ neighbourhood.
    • Walking through time: a window onto the prehistory of the Yorkshire Dales through multi-method, non-standard survey approaches

      Armit, Ian; Gaffney, Christopher F.; Saunders, Mary K. (University of BradfordSchool of Archaeological Sciences, Faculty of Life Sciences, 2017)
      Walking through time: a window onto the prehistory of the Yorkshire Dales through multi-method, non-standard survey approaches Keywords: Yorkshire Dales, prehistory, veneration, natural places, geophysical survey, walkover survey, field-system, clearance, land tenure The large-scale field-systems, ubiquitous across upland and marginal parts of the Yorkshire Dales, are insecurely dated and poorly understood. Apart from some sporadic academic interest, the archaeology of this region has yet to receive the level of scholarly attention it deserves. The research presented here involved an intensive investigation of an area near Grassington, Upper Wharfedale, UK. Detailed field analysis revealed a section of one of these field-systems to be only a single element in a complex, multi-layered prehistoric landscape, which it is proposed may have roots as far back as the early Neolithic. Contextualisation of the survey area against palynological data, radiocarbon dates and comparative material moves the date of inception of the field-systems back to the middle Bronze Age, some 1000 years earlier than is currently assumed. The combination of empirical data and theoretical ideas has allowed a relative chronology to be determined in the survey area, together with the creation of a testable hypothesis surrounding the development of Upper Wharfedale and the wider Yorkshire Dales through prehistory. A sense of place and the veneration of natural places are key themes within this landscape and it was possible through these to draw out elements of prehistoric society and to show the evolution of ideas such as land tenure and monument significance. This dual empirical-theoretical approach is novel in upland landscape archaeology in the UK and is shown here to have significant merit.
    • Weak mutually unbiased bases with applications to quantum cryptography and tomography. Weak mutually unbiased bases.

      Vourdas, Apostolos; Shalaby, Mohamed Mahmoud Youssef (University of BradfordDepartment of Computing, 2013-12-05)
      Mutually unbiased bases is an important topic in the recent quantum system researches. Although there is much work in this area, many problems related to mutually unbiased bases are still open. For example, constructing a complete set of mutually unbiased bases in the Hilbert spaces with composite dimensions has not been achieved yet. This thesis defines a weaker concept than mutually unbiased bases in the Hilbert spaces with composite dimensions. We call this concept, weak mutually unbiased bases. There is a duality between such bases and the geometry of the phase space Zd × Zd, where d is the phase space dimension. To show this duality we study the properties of lines through the origin in Zd × Zd, then we explain the correspondence between the properties of these lines and the properties of the weak mutually unbiased bases. We give an explicit construction of a complete set of weak mutually unbiased bases in the Hilbert space Hd, where d is odd and d = p1p2; p1, p2 are prime numbers. We apply the concept of weak mutually unbiased bases in the context of quantum tomography and quantum cryptography.
    • 'We’re All Getting Older You See, and Things Do Change, Don’t They?’ An Ethnographic Study of Disruption and Continuity in the Daily Lives of Couples Living with Dementia and Co-morbidities

      Downs, Murna G.; Small, Neil A.; De Waal, Denise
      Most people with dementia live in the community with a family member, commonly a spouse. Together they engage in identity redefinition to maintain continuity. Many people living with dementia also have co-morbidities. The aim of this study was to provide a better understanding of the influence of co-morbidities on the lived experience of couples and to provide knowledge to improve services. This had not been researched before. Drawing on the dialectic relationship between the body, habitus, environment and common sense from Bourdieu’s theory of practice (1977; 1990) combined with identity theory as described by Burke and Stetts (2009) I conducted an ethnographic study with five couples over a six-month period. The resulting data were analysed using a framework approach and are presented using case studies to illustrate key points. Drawing up on the data I developed an identity perspective which provides a better understanding of these couples’ daily life experiences taking into consideration the contextuality of people’s multiple identities, experiences, care and support needs and their interaction with the environment and community. My findings illustrate how people with dementia and co-morbidities and their spouses negotiate their identity in daily life in order to continue their daily life routine and cope with health conditions. Furthermore, these identity negotiations influence the acceptance of the diagnoses of dementia, the access to care, services and information and the experience of dementia, stigma and co-morbidities in daily life. Implications include a presentation of the limitations of current concepts of embodied selfhood and the Aging in Place policy for people with dementia. It points to the potential of the identity perspective to shape policy, services and care practice consistent with couples’ lived experience and their needs and preferences.