Browsing by Author "Alzahrani, Ahmed"

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Background Subtraction Using Adaptive Singular Value Decomposition
(Saudi Digital Library, 2023-12-01) Alzahrani, Ahmed; Tabanjeh, Mohammad
Under the direction of (Dr. Mohammad Tabanjeh, Dr. Sergio Da Silva, and Dr. Sanwar Ahmed) We describe an efficient algorithm for background subtraction in video frames using an adaptive singular value decomposition method. By maintaining a subspace model of the static background scene, each incoming frame can be analyzed for new information representing potential foreground objects. The background subspace is iteratively updated in a computationally efficient manner through selective updating of singular vectors and values. Additional, optimizations such as thresholding and periodic forced updates further improve adaptation performance. Both qualitative and quantitative analysis on test imagery demonstrate accurate extraction of moving foreground elements from the background with minimal false positives. The overall approach provides an accurate and robust algorithm for real-time automated background subtraction applicable to tasks such as video surveillance.
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Biochemical Investigation of Zinc Transporters to Discover their Functional Mechanism in Cells
(Saudi Digital Library, 2023-11-02) Alzahrani, Ahmed; Taylor, Kathryn
Zinc is one of the most abundant micronutrients in the human body and it plays a vital role in many normal cellular processes. The cellular zinc level is tightly controlled by zinc transporters, including the ZIP family, which function to increase cytosolic zinc levels. The alteration of this function has been associated with human diseases, including cancer. ZIP7 belongs to the ZIP family of zinc transporters and resides on the endoplasmic reticulum store. It is responsible for releasing zinc from stores after it has been phosphorylated by CK2 on residues S275 and S276. This ZIP7-mediated zinc release inhibits tyrosine phosphatases and activates cellular tyrosine kinases, several of which are associated with progression of cancer. Moreover, two other ZIP transporters, namely ZIP6 and ZIP10, have been demonstrated to be involved in cell growth and proliferation by importing zinc across biological membranes to cause cell rounding and detachment, essential for migration and the first step of mitosis. In order to achieve this, the N-terminus of ZIP6 has to be cleaved before these transporters relocate to the plasma membrane. The present study generated novel constructs to understand the functional mechanisms of these transporters. Firstly, the activation of ZIP7 was investigated by mutating all four residues S275, S276, S293 and T294 predicted to be phosphorylated. This study found that all four of these residues were required for ZIP7 maximal activation. Secondly, the role of N-terminal cleavage of ZIP6 and ZIP10 was investigated by making chimera constructs replacing the usually cleaved N-terminus with the ZIP7 N-terminus, known not to be cleaved. This study found that the N-terminal cleavage of ZIP6 and ZIP10 was required to enable the cells to round up and detach, indicating a critical role for the N-terminus of ZIP6 and ZIP10 in this mechanism. These findings not only help us to understand the mechanism for these transporters but also enable new tools to be discovered for diseases, such as cancer, that are exacerbated by these transporters.
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How do 360-degree annual reviews influence employee motivation in organizations in the UK?
(Swansea University, 2024) Alzahrani, Ahmed; Hardwick, Louisa
This research explores the impact of 360-degree feedback on the motivation, performance, and work engagement of employees within organizations in the United Kingdom. With conventional forms of performance appraisals often failing to enhance the growth and engagement of employees, 360-degree feedback is a more comprehensive approach as it gathers feedback from an employee’s colleagues, subordinates, and superiors. In this study, the effects of such feedback on employee motivation are examined with reference to motivational theories, including Self-Determination Theory (SDT) and Job Demands-Resources (JD-R) theory. The two frameworks propose that addressing psychological needs and regulating resources should promote motivation at the place of work. The study also highlights the growing use of 360-degree feedback in various sectors in the United Kingdom, including the financial, health, and information technology sectors, which currently experience significant challenges due to changes in the working environments, such as remote and blended working models. This study employs Systematic Literature Review (SLR), which can be best described as a systematic approach to reviewing literature. The SLR offers a comprehensive insight into prior literature on a topic by extracting data from articles, case studies, and reports. Specifically, this review examines the literature regarding the impact of 360-degree feedback on employee motivation in the context of the UK and identifies any research gaps. In doing so, it also assesses the comparative suitability of 360-degree feedback with other performance management approaches. The resource of the study is 360-degree feedback, which aims at supporting self-organizing, competency, and peer recognition, as supported by the authors of both SDT and JD-R theories. Therefore, this research seeks to present findings that can support organisations in the United Kingdom seeking to upgrade their performance management tools for the use of 360-degree feedback to motivate and improve the performance of their employees. The results could help enhance the implemented human resource practices as well as fill the gaps in the literature.
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How do 360-degree annual reviews influence employee motivation in organizations in the UK?
(Swansea University, 2024-09) Alzahrani, Ahmed; Hardwick, Louisa
This research explores the impact of 360-degree feedback on the motivation, performance, and work engagement of employees within organizations in the United Kingdom. With conventional forms of performance appraisals often failing to enhance the growth and engagement of employees, 360-degree feedback is a more comprehensive approach as it gathers feedback from an employee’s colleagues, subordinates, and superiors. In this study, the effects of such feedback on employee motivation are examined with reference to motivational theories, including Self-Determination Theory (SDT) and Job Demands-Resources (JD-R) theory. The two frameworks propose that addressing psychological needs and regulating resources should promote motivation at the place of work. The study also highlights the growing use of 360-degree feedback in various sectors in the United Kingdom, including the financial, health, and information technology sectors, which currently experience significant challenges due to changes in the working environments, such as remote and blended working models. This study employs Systematic Literature Review (SLR), which can be best described as a systematic approach to reviewing literature. The SLR offers a comprehensive insight into prior literature on a topic by extracting data from articles, case studies, and reports. Specifically, this review examines the literature regarding the impact of 360-degree feedback on employee motivation in the context of the UK and identifies any research gaps. In doing so, it also assesses the comparative suitability of 360-degree feedback with other performance management approaches. The resource of the study is 360-degree feedback, which aims at supporting self-organizing, competency, and peer recognition, as supported by the authors of both SDT and JD-R theories. Therefore, this research seeks to present findings that can support organisations in the United Kingdom seeking to upgrade their performance management tools for the use of 360-degree feedback to motivate and improve the performance of their employees. The results could help enhance the implemented human resource practices as well as fill the gaps in the literature.
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Optimisation of Laser Doppler Flowmetry to detect pulpal blood flow in permanent maxillary Incisor Teeth
(King's College London, 2024-06) Alzahrani, Ahmed; Harrison, Mike
Background: Traumatised teeth can present a challenge in diagnosis where pulp sensibility tests and radiographic findings can occasionally be unclear or unreliable, especially in children. Pulp vitality testing through laser Doppler flowmetry (LDF) provides objective, painless, and quantitatively monitors pulp blood perfusion instead of relying on subjective sensibility pulp tests and the child’s responses. Aim: To evaluate the clinical utility of LDF in determining reliable pulpal blood flow (PBF) signals in healthy, traumatised, and non-vital mature permanent maxillary incisor teeth, and to establish a diagnostic protocol in the Dental Centre Department in St Thomas’ Hospital. Methods and design: LDF measurements of PBF in maxillary incisors were taken using the MoorVMS-LDF1 instrument. Participants had either traumatised or root canal-treated incisors alongside contralateral healthy incisors, and a control group with healthy incisors. A silicone stent was used to stabilise the LDF probe. This project measured mean flux values, sensitivity, specificity, flux cut-off value, PBF measurements distribution across the vital and non-vital ranges, and the repeatability of LDF tests. Statistical analysis included descriptive statistics, the Kruskal-Wallis test (P >0.05), receiver operating characteristic (ROC) analysis, and interclass correlations coefficient (ICC). Results: 21 participants aged 12 to 59 years old (mean age =24.24 ±13.56) had their 42 permanent maxillary incisors tested. A total of 84 PBF measurements were categorised into three groups: vital/control (n = 62), trauma (n = 14), and non-vital/root canal-treated (n = 8). The mean PBF values of the trauma group were similar to the mean PBF values of the vital/control and non-vital/root canal-treated groups (P = 0.137). Specifically, participants with a healthy tooth and a contralateral traumatised tooth showed no significant difference in mean PBF values (P = 0.182). However, participants with a healthy tooth and a contralateral non-vital root-treated tooth exhibited a significant difference in mean PBF values (P = 0.009). ROC analysis comparing vital and non-vital pulps showed a sensitivity of 87.5% and a specificity of 69.4%. The analysis identified a cut-off value of 4.65 flux and an area under the curve of 0.693, P = 0.031 with a 95% confidence interval of 0.517–0.868. All LDF tests showed good repeatability in measuring with an ICC of 0.785. Conclusion: LDF fails to differentiate non-vital from vital pulps accurately and it cannot distinguish between vital and non-vital pulp readings among traumatised incisors. Although the device used is marketed to assess pulpal blood flow, further optimisation is required before clinical implementation
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REALISTIC ADAPTIVE SIGNAL CONTROL UNDER PLATOONED CONNECTED VEHICLES ENVIRONMENT
(ProQuest, 2023-06-24) Alzahrani, Ahmed; Moses, Ren
Urban traffic congestion has become an increasingly critical issue as the number of vehicle owners continues to rise each year, resulting in increased travel times, fuel consumption, and environmental pollution. Traditional adaptive traffic signal control systems struggle to accommodate this rapid growth in traffic demand, highlighting the need for innovative and efficient solutions to manage traffic in urban environments. Connected vehicle (CV) technology, which enables vehicles to com- municate with each other and infrastructure, has emerged as a promising solution to address these challenges. The integration of CV data can significantly enhance traffic management systems, allowing for more effective traffic signal optimization, improved traffic flow, and increased safety. This dissertation focuses on the development and evaluation of a novel algorithm for optimizing adaptive traffic signals under platooned CVs. The goal is to harness the potential of CV technology and vehicle platooning to improve traffic efficiency, safety, and environmental sustainability in urban settings. By leveraging the unique characteristics of CVs, mixed traffic scenarios, and the dynamic nature of urban traffic, the proposed algorithm aims to address the limitations of existing traffic signal control systems and provide a more efficient and adaptable solution. The study begins with a comprehensive literature review to identify the current state of the art in adaptive traffic signal control systems, CV technologies, platooning, and their integration in traffic management. The review serves as a foundation for understanding the research gaps and opportunities in this field, setting the stage for the development of the proposed algorithm. The main contribution of this dissertation is the development of a robust, efficient, and adapt- able algorithm for optimizing adaptive traffic signals under platooned CVs. A simulation-based framework was designed and implemented to evaluate the performance of the proposed algorithm, considering various performance indicators such as travel times, delays, queue lengths, vehicle stops, fuel consumption, and emissions. The safety implications of the algorithm were also investigated, providing valuable insights into its safety performance. The performance of the proposed algorithm was compared with existing traffic signal con- trol strategies, including both traditional and connected vehicle-based approaches. The algorithm demonstrated superior performance in terms of various traffic parameters and improved traffic safety compared to existing strategies. A sensitivity analysis was conducted to assess the algorithm’s adaptability and robustness under different traffic conditions, CV penetration levels, and platoon formation scenarios. The findings of this dissertation have important theoretical and practical implications for the fields of adaptive traffic signal control and CV technology. The study contributes to existing theories, models, and frameworks in the field, while also providing recommendations for traffic engineers, policymakers, and other stakeholders on how to leverage the research to improve traffic management, alleviate congestion, reduce emissions, and enhance safety. Limitations and future research directions are also discussed, offering potential avenues for further investigation and development in the area of adaptive traffic signal control and CV technology. This research lays the groundwork for the next generation of traffic management systems that can effectively accommodate the increasing traffic demand and capitalize on the benefits of connected vehicles and platooning.
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Secure Data-Sharing Among Healthcare Organisations in Saudi Arabia
(Saudi Digital Library, 2023-07-17) Alzahrani, Ahmed; Wills, Gary
The healthcare sector is suffering from the inefficiencies in handling its data. Many patients and healthcare organisations are frustrated by the numerous hurdles to obtaining current real-time patient information that are leading to delays in treatment. The healthcare sector’s attention has been drawn to blockchain technology for a part of the solution, especially after this technology was successfully applied in the financial sector to improve the security of transactions. The lack of data-sharing in the healthcare sector is considered a significant issue worldwide. This research focuses on the gap by investigating the benefits of using blockchain at the Ministry of Health in Saudi Arabia. The study achieves this by providing a detailed analysis of the healthcare sector and evaluating how blockchain technology improves data-sharing in a more secure way. This research proposes a framework that identifies the factors that will provide data-sharing among healthcare organisations using blockchain. The framework has three categories: healthcare systems factors; security factors; and blockchain factors. These were identified by critically reviewing published studies together with factors from the relevant industrial standards within the context of the Kingdom of Saudi Arabia (KSA). A triangulation technique was used to achieve reliable results in three steps: a literature review; expert review; and questionnaires. This provided a comprehensive picture of the research topic, validating and confirming the results. To construct the framework the factors of the framework were comprehensively studied and extracted from the literature, then analysed, cleared of duplicates and categorised. Once the framework had been developed, to review and confirm it a study was carried out with healthcare IT specialists and blockchain experts. The expert review findings confirmed that all the proposed factors were important, and suggested recategorising one factor and removing another. After revising the proposed framework according to the expert review and recommendations, a questionnaire was distributed to healthcare IT specialists and blockchain experts in various organisations. Its results were analysed via a one-sample t-test and its data integrity analysed using Cronbach’s alpha, showing that all the factors are statistically significant. The confirmed framework has been based on literature and expert reviews and is supported by a practitioner survey. The framework can be used to inform decision-makers and the Ministry of Health about the factors that will provide data-sharing among healthcare organisations using blockchain. A new instrument was developed. A total of 238 IT and blockchain experts in Saudi healthcare organisations used the instrument. It was developed using the framework to identify the factors that will provide data-sharing among healthcare organisations. The instrument was evaluated using two tests that examined the internal reliability and the validity tests. The results from the instrument were used to develop a model using Structural Equation Modelling (SEM). The resulting data clearly showed a good fit of the structural model and measurement analyses. The key outcomes of the validation study revealed that the factors were discovered to have a direct and statistically significant effect on the model. This specifies that the proposed model fits the data and applies to the KSA context. The contributions of this research are as follows: first, it developed a framework within the KSA context and, second, from the framework a data-sharing instrument was developed, the results of which were used to generate a structural equation model. Overall, the outcomes of this study are valuable information in terms of recommendations to experts and healthcare organisations. Simply put, these findings can assist data sharing and encourage the spread of this phenomenon across countries in the Middle East, particularly in Saudi Arabia.
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