التصوير باستخدام طريقة المعاوقة الكهربائية كتقنية تستخدم لأخذ صورة مقطعية وذلك من خلال قياس الموصلية على سطح الجسم , بحيث تكون القيمة التقريبية لتوزيع المقاومة النوعية الداخلية مبنية عن طريق حساب فرق الجهد والتيار الكهربائي. التصوير المقطعي بالمعاوقة الكهربائية عند تردد معين يسمح بتصوير التغيرات فقط في الجزء الحقيقي من الموصلية ويهمل الجزء التخيلي منها والقيم المطلقة. وقد أقترح حلاً لهذه المشكلة باستخدام التصوير المقطعي متعدد التردد التصوير المقطعي بالمعوقة الكهربائية متعددة التردد يعطي صورة ثابتة بواسطة تكوين صورة لتغيير مقاومة الأنسجة مع التردد, ولغرض الحصول على كل المعلومات تم الأخذ في الاعتبار الجزء الحقيقي والتخيلي للموصلية في هذا البحت تم تطوير طريقة جديدة للتصوير الطبقي بالمعاوقة الكهربائية متعددة التردد باستخدام دوال لاجير الثنائية , وحيث أن تحسين صورة التصوير المقطعي بالمعاوقة الكهربائية يعتمد على كمية المعلومات التي يمكن الحصول عليها من القياسات الحدودية تم الأخذ في الاعتبار الجزء الحقيقي والتخيلي للموصلية لقد تم تطبيق هذه الطريقة والحصول على نتائج جيدة من حيث جودة الصورة مقارنة بنتائج تم الحصول عليها في أبحاث سابقة. Abstract Electrical Impedance Tomography (EIT) is a technique which allows cross- sectional image related to the electrical impedance within an object to be reconstructed from a set of measurements made on the object surface. EIT aims to image the conductivity distribution within a test object by making electrical measurements on the surface of the object. In single frequency Electrical Impedance Tomography only the change in the real part of the conductivity can be imaged and not those of the imaginary part of the conductivity or of the absolute values. Multi-frequency Electrical Impedance Tomography has been proposed to solve this problem. In this thesis, there is a new method using Laguerre function in multi-frequency Electrical Impedance Tomography which has been developed, and full information contained in the complex tissue conductivity can be obtained.
جلال مفتاح مهلهل (2009)

In this paper, we present a simulation model for the Universal Mobile Telecommunication Systems (UMTS). For validation purposes, we have developed a much more detailed simulation of the system written in C language. The results of a previous mathematical model showed that, the product form holds in the case of two cells, and the objective of this paper is to prove the same result using simulation, and to show that the behavior of the system is similar to that in the previous work done in the mathematical model. Once the product form of Jackson's Theorem is Shown to hold, then it is possible to go to a more advanced stage to analyze the 3G network, and to get the performance measures, which will help in making decisions at the design stage
W. S. Abughres(3-2006)

Abstract In order to ensure the promise of anytime-anywhere communication to the customers, Mobile operators must be able to support a large number of users over a large coverage area. So Coverage and Capacity are important issues in the planning process for Third Generation (3G) mobile networks. The planning process aims to allow the maximum number of users sending and receiving adequate signal strength in a cell. In Code division multiple access (CDMA), the Coverage and capacity are not independent of each other as in GSM, it is interference-limited system, meaning that if the traffic increases, the serving cell radius decreases, hence the term cell breathing occurs. This work studies the capacity and coverage of a macrocell CDMA network. The cell breathing effect is studied and a new criteria to link Capacity and Coverage is developed, it is named by Capacity-Coverage Product; CCP. Different designations of CCP formula are given. The influencing of various system parameters on this CCP are studied. Knowing this CCP, the capacity and coverage become straight to estimate. The user distribution is very important issue. Most of previous studies treat user distribution as uniform. This thesis considers the case of non uniform user distributions where a more realistic distribution is chosen. A new interference distribution factor is initiated. The impact of this factor on the capacity and coverage is studied. Existing of Hotspot regions of traffic will cause coverage shrinkage. Installation of hotspot microcells BS inside existing macrocell BS is one possible solution to such situations. In this work a microcell is introduced within the macrocell and a new system parameters are obtained such that the coverage and performance are maintained while the capacity is increased.
محمد عبدالرزاق العالم (2007)