Abstract Voice over IP (VoIP) uses the Internet Protocol (IP) to transmit voice as packets over an IP network, like the Internet, Intranets and Local Area Networks (LAN). Here the voice signal is digitized, compressed and converted to IP packets and then transmitted over the IP network. However, at the receiving end, some packets may be missed in its way due to network congestion. This packets loss degrades the quality of speech at the receiving end of a voice transmission system in the IP network. Since the voice transmission is a real time process, the receiver cannot request for retransmission of the missing packets. High speed networks provide real time variable bit rate service with packet loss requirements. The burstiness of the correlated traffic makes dynamic buffer management highly desirable to satisfy the Quality of Service (QoS) requirements. This thesis presents an algorithm to improve and optimize the Adaptive Buffer Allocation Scheme to deal with input traffic based on loss of consecutive packets in data streams and buffer occupancy levels. Buffer is designed to allow the input traffic to be partitioned into different priority classes, and based on the input traffic behavior it controls the threshold dynamically. This scheme allows input packets to enter into buffer if its occupancy level is less than the threshold value for priority of that packet. The threshold is dynamically varied in runtime based on packet loss behavior. The performance evaluation is carried out using simulation and is carried out for two and multiple priority classes of the input traffic "real time and non real time classes". The simulation results show that the Modified Adaptive Partial Buffer Sharing (ADPBS) has better performance than Adaptive Partial Buffer Sharing under the same traffic conditions.
اسماء احمد الكيش (2010)

Abstract The conflict that took place in Libya in 2011, up to the present moment, has greatly affected the electrical power network and resulted in the rise of the voltage instability problem. This was due to loss of the some major transmission lines and certain generation units. Owing to the fact that the southern region of the Libyan network has no generation units, voltage drop phenomena has become a common problem as a result of the long transmission distance, which is approximately 750km. A proposed solution in order to solve this problem is via the utilization of small mobile generation units at the network weak points. This thesis revolves around discussing the voltage instability problem within the Libyan Network and how it can be enhanced when small and mobile generation units are connected to the network weak points. It will also establish and identify where the most weakened buses and regions are so that the mobile units should be connected for the attainment of optimized solution. Moreover, this solution was proposed as it can solve not only the voltage instability problem, but it will also solve the inadequacy in generation issue by circulating additional power within the network. Hence, reduce the load shedding phenomena. Furthermore, the thesis also includes future recommendations to improve and enhance the Libyan network by the addition of new 220kV and 400kV transmission lines that will enable the network to cope with the load growth in the future
ربيع محمد عمر (2014)

تقدم هذه الأطروحة برنامج حاسوبي تفاعلي لتصميم خطوط النقل الكهربائي ثلاثية الأطوار باستخدام MATLAB. يمكن استخدام هذا البرنامج كوسيلة تعليمية داخل وخارج الفصل الدراسي لشرح أساسيات و ضواهر خطوط النقل الكهربائي.تتناول اغلب الكتب المرجعية المتاحة حاليا لمحتويات خطوط النقل التصميم الكهربائي فقط ولهذا السبب فان اغلب طلاب هندسة القوى الكهربائية يتخرجون من الجامعة وبدون دراية كافية عن الجزء المتعلق بالتصميم الميكانيكي والمتمثل في حسابات ارتخاء الخط والشد على الأبراج وزيادة وزن الموصلات نتيجة لتجمع الثلوج أو زيادة سرعة الرياح وتغير كل من ذلك مع درجات حرارة الجو. كما أن هذا البرنامج مزود ببعض البرامج الإضافية الأخرى والمتمثلة في حسابات قيم سعات ومتحاثات خطوط النقل أخدا في الاعتبار السلك الأرضي. كما أن هذا البرنامج يمكن استخدامه لمعرفة المعاوقات والسعات التسلسلية ( الصفرية والموجبة).وقد تم تزويد هدا البرنامج بقاعدة بيانات تحتوى على مواصفات شاملة للعديد من الموصلات المستخدمة في خطوط النقل الكهربائي.كما أن هذا البرنامج يمكن استخدامه لحسابات شدة المجال الكهربائي حول الموصلات وبالقرب من الأرض. Abstract This thesis presents an interactive computer program for three phase overhead transmission line design using MATALB. This program can be used as a self learning tool to understand the course material offered in class and to enhance students understanding to the three phase transmission line subject. This first course is normally given as a core course to all electrical engineering students. Most of the existing text books in power system analysis nowadays cover the Electrical line design only and describe the line performance very efficiently with very few power text books which treat the mechanical line design part. Therefore electrical engineering students with power engineering major are often graduated from school without having sufficient background concerning the mechanical line design features such as; line sag, the mechanical tension at the tower and the conductor sag due to temperature variations or line loading, conductor thermal limit ….etc. The program is also equipped with an additional feature to compute the line sequence impedances and the line sequence capacitances. Other line features are also provided in this package such as ; thermal limit line calculation, line voltage stability phenomena and the electrical field calculation due to transmission line. Therefore using this program the students will then be able to compute the line sequence parameters for both the single circuit as well as the double circuit tower configuration, with and without ground wire. The package has been also provided with a built in data base library to most of the available power line conductors. Therefore power engineering students will then be able to understand the transmission line course contents in more depth and to use the other supporting program modules as a self learning tool for line design and line modeling performance.
.سالم مسعود الكردي (2010)