The ever-increasing wireless applications and services has generated a huge demand for the RF spectrum. The strict and rigid policy of spectrum management by the Federal Communications Commission (FCC) has rendered spectrum a valuable resource. The disproportion in the usage of spectrum between the licensed primary users (PUs) and the enormous unlicensed secondary users (SUs) in the band has created spectrum scarcity. This imbalance can be alleviated by the Dynamic Spectrum Access (DSA) based on Cognitive Radio Network (CRN) paradigm by significantly improving the efficiency of spectrum utilisation of the wireless networking systems. DSA enables unlicensed secondary users (SUs) also known as cognitive radios (CRs) to sense the spectral environment and access the licensed spectrum opportunistically without causing any interference to the licensed primary users (PUs). Spectrum sensing is the most prominent capability of CRs to effectively detect the presence or absence of licensed primary users (PUs) in the band. Sensing provides protection to primary users (PUs) from interference and creates opportunities of spectrum access to secondary users (SUs). However, scanning the spectrum continuously is critical and power intensive. The high-power consumption in battery operated CR devices reduces device lifetime thereby affecting the network performance. Research is being carried out to improve energy efficiency and offer viable solutions for extending lifetime for wireless devices. In this thesis, the work focuses on the energy efficient spectrum sensing of CR networks. The main aim is to reduce the percentage of energy consumption in the CR system in possible ways. Primarily, the conventional energy detection (ED) and the cyclostationary feature detection (CFD) spectrum sensing mechanisms were employed to sense the spectrum. Aiming on energy efficiency, a novel history assisted spectrum sensing scheme has been proposed which utilises an analytical engine database (AED). It generates a rich data set of spectrum usage history that can be used by CRs to make efficient sensing decisions modelled using Markov chain model. The usage of sensing history in decision making, results in decreasing the frequency of spectrum scanning by the CRs thereby reducing the processing cost and the sensing related energy consumption. It shows 17% improvement in energy saving compared to the conventional sensing scheme. The key performance parameters such as probability of miss detection (PMD), probability of false alarm (PF) and probability of detection (PD) were investigated using ROC curves. Extensive performance analysis is carried out by implementing two traditional sensing schemes ED and CFD in terms of computational cost and energy consumption and shows 50% improvement in effective energy saved by using history assisted spectrum sensing mechanism. Further, to address the high energy consumption during communication between CRs / stations (STAs) and the base station (BS), a novel energy efficient Group Control Slot allocation (GCSA) mac protocol has been proposed. Publish/Subscribe (PUB-SUB) and point-to-point messaging models have been implemented for data communication between BS, STAs and AED. The proposed mac protocol increases the number of STAs to enter in to sleep mode thereby conserving the energy consumed during idle state. Furthermore, cluster based co-operative spectrum sensing (CSS) is considered for reducing the energy utilised for data communication between CRs and BS by electing a cluster head (CH) using fuzzy logic-based clustering algorithm. The cluster head (CH) collects, aggregates data from cluster members and it is only the CHs that communicate to the BS. Thus, there is no communication between individual non-CH CRs and BS, thereby significantly reducing the energy consumption and improving the network lifetime of the CR system. Extensive simulations were performed in MATLAB and results are presented for all the proposed schemes.

This thesis discusses the impact of the supercapacitor size on the performance of the mobile battery-less RF energy harvesting system. The choice of supercapacitor is crucial in mobile systems. The small supercapacitor can charge quickly and activate the sensor in a few seconds in the low-energy area but cannot provide a significant amount of energy to the sensor to do heavy energy tasks such as programming or communication with the base station. On the other hand, large supercapacitors have a sensor node for heavy energy tasks in a high-energy zone but may not be able to activate in a low energy zone. The proposed hybrid energy-storage system contains two supercapacitors of different sizes and a switching circuit. An adaptive-learning switching algorithm controls the switching circuit. This algorithm predicts the available source energy and the period that the sensor node will remain in the high-energy area. The algorithm dynamically switches between the supercapacitors according to available ambient RF energy. Extensive simulation and experiments evaluated the proposed method. The proposed system showed 40% and 80% efficiency over single supercapacitor system in terms of the amount of harvested energy and sensor coverage.

The context of this study is the dilemma that most service users of social interventions and practice are poor and yet poverty is marginalised within social work practice. The study therefore set out to explore social work practitioners’ understanding of poverty, attitudes towards poverty and social work and poverty relationship. A qualitative methodology was adopted, involving five focus group discussions and twenty-eight semi-structured interviews within three Local Authorities referred to as research sites. This was more than the originally anticipated sample. A narrative literature review undertaken concluded that social work definitions are contested and this, coupled with regulation of social work, limits social work effectiveness in addressing poverty as it is not one of its major remits. The review identified that poverty is a significant issue affecting most service users and associated with most social problems involved in social work interventions and practice. The review discovered that social work practice pathologizes poverty and generally attributes causation of poverty to service users’ lack of capacity to take advantage of opportunities within the market and provided by the state and a lack of motivation to overcome their problems at the expense of structural factors that either cause or exacerbate poverty. This resonates with individualistic social work frameworks which are risk-averse, reactive, punitive, authoritative, and ineffective given the scale and impact of poverty which seems to be increasing. This is aggravated by the neo-liberal socio-political environment and managerialist social work environment characterised by low morale, high caseloads, paucity of much needed resource for social work interventions. The literature review established that social workers’ attitudes towards poor service users are largely ambivalent and negative. The research data reveals that poverty is a significant and prevalent issue amongst most service users and associated with most social problems handled by social workers. Research participants expressed that there is no shared understanding of poverty, that definition of poverty is important in how it is understood and influencing how poverty is addressed. It emerged that poverty is marginalised in social work education and practice. Research data revealed that poverty is taken as background music and normal. It emerged that poverty is not viewed as a risk factor on its own. Participants revealed that social work lacks capacity, knowledge, and skills to address poverty. Social work education and training does not equip social workers with functional knowledge and skills to address poverty in practice. The research revealed social work professionals’ attitudes are generally negative, stereotypical, and judgemental towards service users. Government policies aggravate service users’ experiences and circumstances. The participants expressed an understanding that thresholds of social work interventions are high and therefore act as barriers. Participants expressed that poverty is an uncomfortable subject to discuss with service users given stigmatisation associated with being poor. This therefore results in service users hiding their financial struggles. It emerged that service users who are poor are discriminated against and punished to experiencing poverty and that this goes against main social work values. The findings echo findings undertaken by many academics and researchers in social work poverty and therefore add to the body of knowledge in social work and poverty The study recommends that that consideration should be made that poverty is taught as a main course in social work education and as a post-graduate course for social work in practice. It is also recommended that social work should promote poverty discourse at the policy level with a view to influencing structural change. It is also recommended that adequate funding be provided for poverty practice, family support and early intervention and prevention. It is also recommended that that government policies that impact negatively on service users be evaluated. Service users should play an integral role in all these recommendations.

Data is a crucial factor within machine learning, as most of the neural networks and machine learning models are data-driven. A trained neural network can be used to predict new data that has not been seen by the model but under the trained patterns. The performance of the predictive model can vary based on the data that is being used while training. Multiple metrics have been produced after a model is trained to evaluate model performance. However, it is difficult to get an intuitive measurement that indicates if the data pre-processing of a model has been improved or not. Therefore, a constructive performance indicator tool that can be used to intuitively measure the performance of pre-processing mechanisms for a given model, has been developed through multiple experiments with 32 datasets. The experiments are set up by collecting multiple unstructured datasets which are subsequently converted into structured datasets and then evaluated by their modelling performance. The experiment results are used to evaluate the importance of each metric and priorities via weights for contextualising the preprocessing experience within the constructivist paradigm. Furthermore, a set of tools have been developed throughout the project to improve the efficiency of machine learning experiments. The developed set of tools are a part of the main software, which is named as the pre-processing assistant. The pre-processing assistant has been published to the public, and it can be used for preparing, processing, and analysing data. The software tools allow users to manipulate datasets and generate Python scripts to train a predictive model. Also, the TensorFlow framework and its machine-learning algorithms have been utilised to develop Python scripts for training and predicting datasets. The software has been used to effectively carry out the experiments which have helped to configure the performance indicator tool. In the end, the most important metrics have been discovered through various experiments. The experiments consist of training the model with and without data pre-processing techniques. The increase in each metric has been adopted to discover significant metrics. The metrics which improve frequently are estimated to be more critical and have been assigned with a higher weight. The performance indicator has been configured based on the final experiment results, and it can be used by others to measure the performance of a predictive model.

Professional identity formation is a process that happens simultaneously at the level of the individual (which involves their internal cognitive development), at the interactive level (which involves socialisation through participation) and at the institutional level (which involves being subject to institutional processes). Having a well-developed professional identity is important, as it helps professionals to practise with confidence, provides a sense of belonging, aids normative behaviours and has been linked to better quality care. Whilst research has highlighted the factors that support professional identity development in other professions, there is limited understanding of the factors that student osteopaths use to construct their professional identity. The aim of this study was to construct a theory of how undergraduate osteopaths in the UK construct their professional identity and to determine whether undergraduate osteopathic students have conceptions of an osteopathic identity. A qualitative study was undertaken within a constructivist paradigm. A total of seven UK undergraduate osteopathic students were purposively sampled. Data was collected through all seven participants keeping a diary for one month. Following this, individual interviews were undertaken with all participants. Participant diaries acted both as data and as a reflective prompt for the individual interviews. Subsequent theoretical sampling informed the data analysis. Interviews were audio recorded and transcribed. Towards the end of the study, one participant was selected for a second interview. A constructivist grounded theory approach was used to code and analyse the data and to construct the grounded theory of how undergraduate osteopathic students in the UK construct their professional identity. The data resulted in the construction of a theory that encompasses three interrelated levels. At the individual level, students held a conception of their future self as an osteopath, which they used to motivate themselves and measure their progress. They constructed this future self as an osteopath by the interactive process which became known as ‘Magpieing’. This involved the collection of identity contents from tutors, peers and documentation. Students then experimented with these identity contents with either patients or peers before making the decision to integrate the content, continue to experiment with it in other situations or discard it. This was underpinned by institutional level processes that constituted providing students with role models and mentors, clinical encounters and safe spaces where they could collect and experiment with identity contents. Students held a conception of an osteopathic identity base on three levels: ways of interacting with patients, professionalism, and knowledge and ways of using it. They associated most strongly with ways of interacting with patients and least strongly with knowledge and ways of using it. The findings indicate that undergraduate osteopathic students in the UK construct their professional identity on an individual, an interactional and an institutional level, and that these levels are interrelated. Undergraduate osteopathic students in the UK have a conception of the professional identity of osteopaths based on three levels, with which they strongly or weakly associated. These findings provide the first theory of how student osteopaths construct their professional identity.

Aim: In the UK it has been reported that over 50% of the police workforce has taken sick leave for mental or physical health issues within the past five years. Bedfordshire Police Force has the fourth highest long term sick leave in the UK due to both physical and psychological health. Method: The study employed mixed methods across four phases of work (1. needs assessment, 2. Baseline assessment, 3. Intervention implementation, 4. Evaluation) to assess the physical health (body mass index, blood pressure), psychological wellbeing (stress anxiety, depression, mood, wellbeing), health behaviours (physical activity, nutrition, substance use, sleep), support needs and factors that influence the health and wellbeing of Bedfordshire Police employees. The study moreover tested the feasibility of brief positive psychology interventions (3 Good Things [expressive writing] Technique and Positive Password Mantras) for a length of 1 month. Results: Stress levels (personal, organisational and operational) and BMI were high in Bedfordshire Police Force employees and significantly correlated with poorer health behaviours. Recruitment to the interventions was low, and attrition over the four weeks was high, suggesting the current approach was not feasible. Interview findings indicated that future initiatives need to 1) Build belief in the support available; 2) Address perceived stigma; 3) Provide timely support; 4) Reduce work-related stress; 5) Make health and wellbeing a priority; 6) Encourage camaraderie and social support, and 7) Support positive coping strategies. Conclusion: There is a clear need and desire for occupational health support within Bedfordshire Police Force to support employees’ physical health and psychological wellbeing. Future interventions should consider employee’s capability, opportunity and motivation to engage and make initiatives easy, attractive, social and timely.

Background: Stigma is prominent in the lives of autistic children and their families, and a systematic literature review found that autism-related stigma contributes significantly to poorer mental health among parents. Parents are also at risk of internalising the stigma directed at their child, which further exacerbates poor well-being. Interventions that focus on the mental health of parents of autistic children are sparse, and there are currently no interventions available that help parents cope with autism-related stigma as well as prevent the internalisation of stigma. An intervention that is evidenced to improve mental health in part through increasing resistance to stigma will be of substantial benefit to families and, ultimately, their children. Purpose: The primary aim of this study was to develop a stigma protection intervention aiming to improve the mental health of parents of autistic children, and to evaluate its feasibility and acceptability. The secondary aim was to explore the preliminary impact of the intervention on the mental health of the parents. Methods: The Medical Research Council’s guidelines for developing complex interventions were used as a framework for the research. Evidence from multiple sources was synthesised to produce an eight week blended (face-to-face and online) psychosocial intervention titled ‘SOLACE’. A randomised controlled trial was carried out comparing parents allocated to the SOLACE group (n=9) with those allocated to a control group (n=8) (no intervention). Mixed methods were employed to investigate feasibility, acceptability, and preliminary outcomes. Recruitment and retention rates, missing data and adverse events were recorded to assess feasibility. A qualitative focus group was conducted to evaluate the acceptability of the intervention and outcome measures. Outcomes were measured at three time points: baseline, post-intervention and at six weeks follow-up. The primary outcome of interest was mental health (MHI-5). Other outcomes of interest included measures of courtesy stigma, self-stigma, self-esteem, positive meaning in caregiving, self-blame, self-compassion, social support, and social isolation. Results: Recruitment rates were lower than anticipated, yet the retention rates were excellent, with no dropouts and minimal missing data. Attendance rates were particularly high for this population, with 80% of parents attending more than 50% of the sessions. The findings of the qualitative evaluation showed that SOLACE was acceptable to parents and that the combination of online and face to face delivery worked well. Quantitative analysis revealed that mental health scores had significantly improved for those who took part in SOLACE compared to no significant changes for control group participants. In addition, changes in secondary outcome measures were in favour of SOLACE. Conclusions: A stigma protection intervention that improves the mental health of parents and carers of autistic children in an acceptable and feasible way has been produced and evidenced for the first time. A number of recommendations are made for future use in a larger, powered trial. The knowledge derived from this thesis may be used to help inform future service provision for parents and shape future autism policy so that the importance of stigma in relation to parent mental health and their caregiving role is emphasised.

Electronic word of mouth (eWoM hereafter) represents a low-cost and powerful tool for companies to attract new customers. Despite the challenge in creating positive eWoM, celebrity chefs, as representative of personal branding, generate a significant amount of eWoM within their social media brand communities. Two recognised spectra of consumers’ brand-associated communications—eWoM and celebrity chefs in the perspective of personal branding—are the interest of this academic research. Up to now, these streams of literature have seen little intersection, as they typically take their distinct individual research directions. Regardless of frequent occurrence within the celebrity chef’s social media page (Relling et al., 2016) little is identified regarding eWoM triggered by the perceived factors of celebrity chefs. Nevertheless, as there is a non-existing connection in literature and a consequent lack of academic research linking celebrity chefs (in the perspective of personal branding) and eWoM, there is also inadequate understanding of what are the eWoM motivations triggered by celebrity chefs’ perceived factors. Moreover, as per the knowledge of the researcher, this is the first research which investigates why eWoM motivation does not lead to creating actual eWoM, or the intervening factors. This study follows a multi method qualitative approach and is in two segments. The first segment of the research conducts a Netnography study involving non-participant observation within the celebrity chefs’ social media brand communities. The second segment of the research has adopted a semi-structured interview method to explore the eWoM motivations for the generation of eWoM. Moreover, the interviews also explore the factors that intervene in the transformation of eWoM motivation to eWoM messages. The findings of this research highlight key perceived factors of celebrity chefs which trigger eWoM motivation. Moreover, the interview phase reveals eWoM motivations triggered by these factors. Some of the eWoM motivations identified will be a new contribution to the literature. Furthermore, the factors are explored in relation to why eWoM motivations do not create actual eWoM. As per the knowledge of the researcher, this is the first time intervening factors which do not lead eWoM motivation to create eWoM messages have been considered and researched in the context of celebrity chefs’ social media brand communities. At present, social media is an effective tool to attract customers by generating eWoM messages. This research has the potential to address celebrity chefs, or those who are interested in personal branding, social media regulators, social media strategists who can gain a profound understanding of which factors influence the social media participants in terms of creating positive and negative eWoM messages, and why the paticipants do so. Keywords: eWoM, celebrity chefs, social media marketing, personal branding, social media brand communities.

Background: Water creates a hydrostatic pressure on the body when immersed (Bove, 2002). This redirects blood to the thoracic cavity leading to an increase in cardiac output (Q̇), stroke volume (SV) and a decrease in heart rate (HR) and blood pressure (BP) ( Šrámek et al., 2000). The aim of this study was to use echocardiography to report the full effects of water immersion. Method: Sixteen participants were immersed to the neck in waters of 30°C in three postures (standing, sitting and laying) for 20 minutes. BP, HR and a full echocardiogram of the left ventricle was performed. This was recreated on land. Results: SV (14.2%), Q̇ (12.5%), and EDV (7.7%) increased and HR (5%), SBP (11.2%), WS (12.1%) and DBP (13.9%) decreased (all P<0.05) in water when compared to land. Sitting demonstrated the greatest effect on the variables. Conclusion: Water immersion displayed favourable adaptations to the myocardium, this is due to an increase in venous return stimulating the parasympathetic nervous system and dilating arteries and reducing BP and HR. These adaptations encourage the heart to work more effectively at a lower rate, improving cardiovascular health.

Background Addressing the shortage and increasing the ‘home grown’ NHS workforce is a key aspect of the Government’s Widening Participation agenda British South Asians (BSA) and men are underrepresented within the nursing workforce. Existing evidence highlights some salient barriers (and enablers) for underrepresented groups entering and progressing in nursing careers. There is however little evidence exploring the experiences of ‘home grown’ BSA men. Therefore, this study aimed to take an intersectional approach to examining the barriers and enablers for BSA men entering and progressing in NHS nursing careers in England. Methods A convergent parallel mixed methods approach was adopted. A quantitative secondary descriptive analysis (using proportion ratios, for comparison between BSA and White men, using confidence intervals to test statistical significance) was conducted on national data on applications (n=150,445 applicants over 3 year period), acceptances and attrition rates (n=416,457 total enrolled students over 3 year period) in relation to nursing pre-registration courses in England and NHS nursing workforce (n=1,254,368 full time equivalent staff posts) from 2013-2016 inclusive. Qualitative focus groups were conducted in Luton, with BSA young men (n=22) and BSA parents (n=35). One to one interviews were conducted nationally with professionals and stakeholders (n=5 nurses, 5 other professionals) to ascertain their views. A Framework Approach was used for analysis purposes. Results and Findings The review of national data showed that BSA men are twice as likely to apply for nursing pre-registration courses than their British White male counterparts (PR=2.32: 95% CI: 2.22-2.42); half as likely to be accepted on nursing pre-registration courses (PR=0.54: 95% CI: 0.47-0.62); 18% more likely to leave their nursing course without achieving the intended award (PR=1.18: CI 95%: 1.15-1.21); and underrepresented in senior, management or specialist roles within the workforce (PR=0.35: CI 95%: 0.30- 0.40). The focus groups and interviews revealed a number of themes. Barriers included poor pay and conditions negative family views, negative media representations, ethnicity including culture; religion; masculinity and gender, a lack of knowledge and awareness of the nursing profession, and less favourable comparison of nursing with medical doctors as a profession. Enablers included personal circumstances, role models including friends and family, ethnicity including religion and masculinity and nursing as a noble profession. Conclusion and Recommendations Quantitative results suggest variation in nursing education outcomes based upon ethnicity which merit further enquiry via qualitative research to identify institutional barriers in selection practices. Difficulties in identifying ‘home grown’ BSA nurses (as opposed to internationally recruited nurses in the NHS workforce) highlight a significant challenge for benchmarking aspirations to develop a ‘home grown’ workforce. Data capture systems should be reviewed in the light of this finding. Qualitative findings suggest the need for culturally specific interventions to reduce the stigma associated with nursing in the BSA community to attract a more diverse nursing workforce, including an emphasis on the values common to BSA masculinities and aspects of the nursing profession. BSA male nurses experience institutional racism, which impedes their career progression, therefore NHS employer organisations should review relevant recruitment and retention policy and practice for this group.