PHD theses : Engineering
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Item Artificial Neural Network Based Fault Location for transmiss ion line(AlNEElAN UNVERSLTY, 2019-03) EIMAN OMER MOHAMMED SALEH BabikerItem Control of Autonomous Vehicles Using Intelligent System(Al-Neelain University, 2019-05) Ahmed Athnin Nusk AhmedWheeled mobile robots (WMRs) have been used in industries to move things from place to place, where the robot has to know its specified trajectory. For the WMR to track it's desired trajectory, a good control law is needed, such that the robot can follow its path with a minimum error. This work presents the tracking control of WMR utilizing a nonlinear control method based on backstepping approach. The kinematic model of WMR is obtained. The pro-posed controller is evaluated through circular path via simulation work using MATLAB/SIMULINK. Furthermore, the thesis illustrates image recognition based on backpropagation ANN (BP ANN). The BP ANN is trained via video stream to detect and recognize traffic light signal. It's found that, the proposed controller can perform the tracking task of WMR with minimal error. Moreo-ver, the BP ANN can recognize the traffic light signal with good accuracy. It's recommended that to use BP ANN with WMR for outdoor navigation to detect the traffic light signals. تم استخدام الروبوتات المتحركة ذات العجلات في الصناعات لنقل الأشياء من مكان إلى آخر ، حيث يجب أن يعرف الروبوت مساره المحدد. لكي يتتبع المسار المطلوب ، هناك حاجة إلى قانون تحكم جيد ، بحيث يمكن للروبوت أن يتبع مساره بأقل قدر من الخطأ. يقدم هذا العمل التحكم في التتبع باستخدام طريقة التحكم غير الخطية القائمة على نهج الخوارزمية ذات الخطوات الرجعية. تم الحصول على النموذج الحركي للروبوتات المتحركة ذات العجلات. يتم تقييم وحدة التحكم المقترحة من خلال مسار دائري عبر أعمال المحاكاة باستخدام بيئة برنامج الحاسوب متلاب. وايضا، توضح الأطروحة التعرف على صور اشارة المرور باستخدم نظام شبكة اعصاب صناعية. لاكتشاف إشارة المرور والتعرف عليها لقد وجد أن وحدة التحكم المقترحة يمكنها أداء مهمة تتبع الروبوتات المتحركة بأقل قدر من الخطأ. وبعد الاختبار وجد نظام الشبكة العصبية الامامية الانتشار اظهرت نتائج دقيقة مقارنة مع الشبكات العصبية الاخرى وذلك له تأثير كبير في تحسين العربات ذاتية القيادة.Item The Sequential Elicitation System for Requirement Process Enhancement (SESRPE)(Neelain University, 2019) Hatim Mohammed Elhassan Ibrahim DafaallaAbstract Requirements elicitation is the process of identifying software or system requirements from various sources through interviews, workshops, workflow and task analysis, document analysis, and other mechanisms. It is typically, the first phase of requirement engineering, therefore it can be argled that requirements elicitation is in fact the first stage of the software development lifecycle, and consequently, a prerequisite for all the other major development activities. Requirements elicitation is all about learning and understanding the needs, desires, and expectations of users and customers. The unfortunate failure reports in IT systems development depict an enormous cost. Concerning the fact that trends show the failure rate have gone up, while the number of successful ones has decreased in the last five years, Clearly, the failure of information systems projects is a global problem of significant size, attributed to the wrong requirement elicitation practices at the first phase of the projects. The research focuses on the requirement elicitation process with respect to requirement engineering. Accordingly, three major issues of the requirement elicitation processes are considered in this research: the improper elicitation technique selection, conflicted requirement as a result of communication obstacles, and the lack of hidden knowledge / missing requirements detection mechanism. Hence, the researcher proposed a Sequential Elicitation System for Requirement Process Enhancement (SESRPE) for the requirement elicitation. The elicitation system (SESRPE) consists of three different subsystem models; each tackles a different problem domain: Elicitation technique selection model, missing/hidden requirements detection model, conflict resolution, and communication model. The elicitation technique selection model solves the issue of the improper technique selection that leads to improper requirements output. The proposed mathematical model relies on the system analyst, stakeholder, and techniques surveyed attributes ratios to train the data using k-nearest neighbors’ algorithm to provide the best optimal technique nomination according to the elicitation case complexity. The requirements conflict resolution and communication model solve the issues rooted in the communication pattems, resulting in ambiguity, misinterpretation, incomplete requirement, inappropriate requirement, and requirements conflicts. The proposed model classifies the techniques according to their knowledge, transfers preference, secures the stakeholder’s involvement using the resistance protocol, introduces the conflict detection and resolution mechanism based on the nonnalized cross correlations function (NCCF), and the standard error (SE) function effectively, to refine the conflicted requirements and measure the requirement accuracy. The missing/hidden requirements detection model solves the issue of the unknown requirements. The proposed model relies on a procedural process to detect and classify the new requirements based on the given project characteristics and boundaries. The algorithmic design of elicitation system (SESRPE) has the ability to produce a clear and complete set of conflict free requirements, effectively to elevate the success rate of the IS projects, define the project budget boundaries and reduce time spend in the elicitation process. The elicitation system (SESRPE) is designed to be flexible and adaptable to handle requirement volatility and complexity.Item Hand over in a Hybrid Visible Light Communication (Li-Fi) and RF Radio Frequency (Wi-Fi) networks using Adaptive Neuro-Fuzzy System (ANFIS)(Neelain University, 2018) Hanaa Omer Aboalgasim OmerABSTRACT A hybrid LiFi/RF network where the LiFi attocell covers a few square meters, user movement may prompt frequent handovers, and the handover overhead would degrade the system throughput. The goal is to reduce the handover overhead by appropriately assigning users to either the RF or the LiFi access point (AP). This project proposes a novel adaptive neruo- fuzzy logic (ANFIS)-based decision-making algorithm for VHO, which is capable of combining the merits of both schemes to achieve excellent handover, the proposed fuzzy logic based VHO decision-making algorithm has the potential to provide lower errors and better quality of service (QoS) to users in future wireless broadband communications. The desired results of execution and implementation were reached and error value is equal 3.85e-7.Item SETTING QoS Wi-Fi PARAMETERS FOR THE SUDAN(Neelain University, 2018) Diaeldin Awad Abdelrahman ElgamelAbstract Sudan telecom market has no existing parameters for WiFi QoS parameters The main objective of this research is to set four QoS WiFi parameters (delay, retransmission attempts, jitter and throughput) to overcome the complete absence of such parameters for QoS WiFi in Sudan, Wifi QoS parameters has to be considered as an important factor for the wireless technology, hence they should be organized and controlled to meet the end users quality of service (QoS) perceptions . Difficulties and challenges face the research, as a few countries have their QoS WiFi parameters. Number of related experiences on the topic handled by author was addressed and analyzed, which were taken as references for the research as a bench mark. Simulation software Opnet 17.5 has been fed with the experimental inputs, and was used to generate the parameters by feeding the simulation with the adequate inputs. Many published research were addressed to compare the simulation results with. Simulations resulted parameter, addressed, analyzed and discussed. Many recommendations were proposed, from which the regulator was asked to consider these parameters as a pilot scheme and could be mandated to WiFi providers in Sudan market, recommendation for enhancement and generating annual reports was upraised. The metric parameters values obtained were compared with the references results. The final output metric parameters, has been recommended as pilot values for the four addressed parameters. A completion of the remaining QoS WiFi parameters by authority or researchers is highly recommended. المستخلص سوق الإتصالات بالسودان لا توجد به بارمترات لجودة خدمات الواي فاي . من أهم أهداف هذا البحث إيجاد قيم رقمية لأربعة من بارامترات جودة خدمات الواي فاي وهى:- (تأخر وصول البيانات ,عدد محاولات إعادة الإرسال ,التغير الحادث من تأخير وصول البيانات ,النفاذية ). تعتبر بارميترات جودة خدمات الواي فاي من أهم عناصر التكنلوجيا اللاسلكية ,وعليه لابد من تنظيمهم والتحكم بهم لمقابلة إحتياجات المشتركين . لقد واجه البحث بعض الصعوبات لقلة عدد الدول التي وضعت بارميترات لجودة خدمات الواي فاي . وقد تناول البحث عدد من الأوراق ذات العلاقة بموضوع البحث وتم إخضاعها للدراسة واتخذت بعض الأبحاث كمراجع البحث . تم إستخدام المحاكي أوبنت (17,5) في هذا البحث لإستخراج النتائج وفد تمت مقارنتها بالأبحاث المنشورة كمراجع للنتائج .Item A New Algorithm for Blind Source Separation Using Parallel Processing(Neelain University, 2006) Ibrahim Elimam AbdallaABSTRACT In this dissertation the digital filters were used to solve the Convolutive Blind Source Separation within the parallel computing context, A revision of the strategy of tackling BSS and CBSS problems via parallel computing was proposed. In this dissertation a convolutive Blind Source Separation algorithm was developed within the context of parallel computing. The algorithm finds the demixing system by simultaneously jointly diagonalizeing a set of time-lagged correlation matrices by using parallel form of Jacobi plane transformations. The parallel computing approach was applied on some existing BSS and CBSS algorithms. As an example of the iterative CBSS algorithms Lambert and Bell work was selected and modified so as to apply parallel computing approach. Very good results were obtained compared with Lambert and Bell results. A very important improvement is that the developed equalizing system converges very fast. As an example of the diagonalization algorithms the JADE algorithm was modified to apply parallel computing approach. The results of the simulations showed that applying parallel computing approach on this type of algorithms is easier if done on shared memory systems.Item Technical Risks Associated With Some Sudanese Telecommunications Networks And Proposed Solutions(Neelain University, 2016) Mohammed Tahseen Eid Al AghaAbstract As today’s business world is dynamic and constantly changing, a plenty of surprises and risks taken into consideration appear suddenly, leading to block the implementation of engineering projects or may cause a total collapse. The dissertation focuses on three main issues: 1) technical risks associated with telecom transmission media. 2) multiple criteria and decision making, 3) cost and schedule risks associated with telecom network. This research highlights the use of the advantages ‘of performing qualitative and quantitative analysis techniques as a methodology to provide better information to support critical decisions. These methodologies help to evaluate and estimate the size of contingency reserves for the time and cost that would be appropriate for stakeholders. The technique used in the risk assessment is focused on five main issues: 1) Root cause analysis method which is a serious method of problem solving. 2) Expected monetary value which is a simple calculation of a value such as expected cost target. 3) Decision tree analysis that is a pOWCl’fill utility for choosing an option from alternatives. 4) Analytical Hierarchy Process (AHP) in order to make decision in complex problems. 5) Simulation models such as sensitivity analysis and Monte Carlo simulation in order to meet sufficient results in cost estimation and schedules. In the first scenario, a complete risk register is constructed involving risk identification, risk triggering, risk severity, risk analysis, risk response, and risk monitoring. The second scenario represents decision making in telecom companies to select the best suitable and appropriate transmission lines types. _Six criteria were identified such as Installation cost, capacity, Security, immunity to noise, issue of latency, and distance for getting the best type of transmission lines among the three alternatives options such as fiber optic, VSAT, and microwaves under consideration. The third scenario shows a simulation- based approach of assessing the risk and uncertainty involved in estimating the expected eamings of a mobile communication company according to traffic intensity principle. The procedure involves using of sensitivity analysis modeling, and spreadsheet sofiware, such as Excel, is a common tool for perfonning this model. This method shows the influence of five main factors influencing the effectiveness of trunking theory. This leads stakeholders to avoid the risks associated to cost by taking attention to the five parameters related to mobile traffic intensity such as number of users, number of calls, call duration, initial cost of call duration, and price of call duration. The research also provides some of the obstacles faced by telecommunications companies such as the problem of increase network capacity, in order to support many new users. To complete this task, Monte Carlo simulation is applied. Monte Carlo is a computerized mathematical technique that allows people to account for risk in quantitative analysis and decision making. The pr0ject’s problem is divided into four jobs; Hardware Installation, Software Configurations, Electrical wiring, and Civil Works. Based on prior experience or other expert knowledge, risk manger can determine the best case, most-likely, and worst-case estimates for each of these activities.Item RESIDUAL SERVICE TIME BASED ANALYSIS OF MULTI-CLASS MULTI-SERVER PRIORITY . QUEUING SYSTEMS(Neelain University, 2007) Amin Babiker A/Nabi MustafaABSTRACT In this research, Multi-Class Multi-Server Priority Queuing Systems. service times for all priority classes are assumed to be identically and exponentially distributed. This assumption led to the possibility of extending the analysis of non- preemptive priority queuing systems to the multiple servers case (similarly to multiple communication channels). ' The extension is based on the developed fomiula for the residual service time R. This on its part, was achieved by utilizing the analysis of M/M/m systems in which the service times are identically and exponentially distributed, combining this with the analysis of non-preemptive queuing systems for single server systems based on M/G/l system. Making all necessary modifications for the system to fit the multiple servers case, the necessary mathematical analysis and derivations were given. The Preemptive Priority queues with Multiple Servers and Multiple priority classes were treated in the same manner. Here the assumption that the service times - for all priority classes — are identically and exponentially distributed _is put forward. Again, a formula for the residual service time is developed and utilized in calculating the average customer waiting time and other related parameters. In the light of this assumption the author presents the relations necessary to derive an expression for the mean residual service time which is then used in developing a mathematical model for the analysis of preemptive priority queues with multiple servers and multiple priority classes. The research includes some comparative studies between the proposed model (multi-class multi-servers priority queuing systems) and some prior related works.Item A New Algorithm for Blind Source Separation Using Parallel Processing(Al Neelain University, 2006-11) Ibrahim Elimam AbdallaIn this dissertation the digital filters were used to solve the Convolutive Blind Source Separation within the parallel computing context, A revision of the strategy of tackling BSS and CBSS problems via parallel computing was proposed. In this dissertation a convolutive Blind Source Separation algorithm was developed within the context of parallel computing. The algorithm finds the demixing system by simultaneously jointly diagonalizeing a set of time-lagged correlation matrices by using parallel form of Jacobi plane transformations. The parallel computing approach was applied on some existing BSS and CBSS algorithms. As an example of the iterative CBSS algorithms Lambert and Bell work was selected and modified so as to apply parallel computing approach. Very good results were obtained compared with Lambert and Bell results. A very important improvement is that the developed equalizing system converges very fast. As an example of the diagonalization algorithms the JADE algorithm was modified to apply parallel computing approach. The results of the simulations showed that applying parallel computing approach on this type of algorithms is easier if done on shared memory systems.Item Studies on the Effect of Electromagnetic Field Exposure on Experimental Animals(Neelain University, 2011) Yassir Salaheldin Khalil OsmanAbstract The study was planned to evaluate the effect of two different electromagnetic fields (EMF) on experimental animals at different exposure levels. In the first experiment, the mice were exposed to isothermal non-ionizing EMF, represented by the man-made visible light (artificial visible light of intensity of 77 mW/cmz on the area of 72.5 cmz and frequency of EM radiation within (3.9x1Ol4 Hz and 7.5x10'4 Hz W/cmz) 8 hours per day for 3, 6 and 12 days respectively . In the second experiment, mice were exposed to lmT magnetic field (MF) (12 hours/day) for 15, 30 or 60 days. The present used strengths were chosen because they are almost similar to the level of human exposure. The first experiment showed that exposure of mice to visible light caused time-dependent dramatic histological alterations of the testis and pituitary glands. Exposure caused severe degenerative effects on the testes histological architecture, size and reduction in the seminiferous tubules‘ diameters. Transmission electron microscopy (TEM) clarified that the degenerative effects were evident in all germ and Sertoli cells. In the pituitary glands, visible light caused degenerative effects in the gonad trope cells, mild to moderate hemorrhage after 3 and 6 days of treatment, and severe hemorrhage and shrinkage of most pituitary gland secretary cells after 12 days. Serum biochemical analysis of testosterone, follicular stimulating hormone (FSH), luteinizing hormone (LH) and the hypothalamus Gonad tropic releasing hormone (GnRH) that stimulates the pituitary gland regulation of testicular testosterone through the FSH and LH hormones were allfound to be time-dependent and significantly decreased by exposure particularly after 12 days. Visible light did not affect the serum total protein levels, aspartate aminotrausferase (AST) activity, alanine aminotransferase (ALT) activity or growth hormone (GI-I) levels. DNA ploidy analysis revealed no carcinogenic effect on the pituitary glands, however it revealed significant down regulation of the proliferative activity of the cells after 12 days. On the other hand, the results of experiment (2) showed no histopathological effects of type of magnetic field on any organ of the mice. The results indicate that man-made visible light but not static magnetic field may affect the endocrine homeostasis of mice by exerting histopathological changes in the pituitary glands cells that may subsequently cause a harmful effect on the testis through reducing the gonad tropic hormones activities that regulates testicular spermato genesis and integrity