التصوير الطبقي ذو المعاوقة الكهربائية (EIT) هو تقنية تسمح بإعادة بناء صور المقطع العرضي المتعلقة بالمعاوقة الكهربائية من خلال مجموعات مقاسه من سطحها، الدافع الرئيسي من تطوير التصوير الطبقي ذي المعاوقة الكهربائية(EIT)هواحتمالية تطبيقه في مجالات التصوير الطبية، وكما هو معروف فأن النسيج الحيوي له مدي معاوقة كهربائية واسع والعديد من الأحداث الفسيولوجية محسوبة بتغيرات المعاوقة الكهربائية، و موصلية نسيج جسم الإنسان فيها اختلافات كبيرة، لذا يجب أن تعطي صور الموصلية مقارنة عالية بين الأنسجة الناعمة. وتعتمد تقنية التصوير الطبقي ذي المعاوقة الكهربائية على إعادة بناء توزيع الموصلية في جسم الإنسان، وذلك من خلال القياسات الخارجية التي يتم قياسها عند تمرير التيار خلال المجسات الموجودة على الجسم والتيار المار، والجهد المقاس يعتمد على الموصلية المراد إيجادها، وتهدف كل خوارزمياتِ وإعادةَ البناء إلي تَقليل الأخطاءِ، والحصول على صور ممتازةِ. إعادة بناء الموصلية في التصوير الطبقي ذي المعاوقة الكهربائية (EIT) تعتبر مشكلة، وبشكل عملي تحل هده المشكلة ببعض طرق التنظيم أو الفرضيات المطبقة لتحسين نوعية الصورة.للحصول على أفضل بناء صورة ممكنه للتصوير الطبقي ذي المعاوقة الكهربائية تم في هذا العمل إجراء مقارنة بين العديد من طرق التنظيم وكانت معتمدة على تعديل النسبة بين أكبر وأصغر القيم الصغيرة والقريبة للصفر داخل مصفوفة الحساسية وتم تطبيق ذلك في طريقة جديدة.كما تم في هذا العمل أيضاً تطوير طريقة جديدة تتعلق بالتصوير الطبقي ذي المعاوقة الكهربائية وتسجيل الصورة و تم الحصول على المعلومات الكاملة في الصورة الجديدة. Abstract Electrical Impedance Tomography (EIT) is a technique which allowscross-section images related to the local electrical impedance within an object to be reconstructed from sets of measurements made on its surface. The main drive behind the development of Electrical Impedance Tomography (EIT) has been its possible application in medical imaging, as biological tissues are known to exhibit a wide range of electrical impedances and many physiological events are computed by electrical impedance changes. The conductivity of the human tissue has large variations so images of the conductivity distribution should give high contrast of soft tissues. In electrical impedance tomography (EIT) the conductivity distribution is reconstructed from measured boundary potential when current sources are applied to the boundary of the object. Both internal current paths and potential distribution depend on the unknown conductivity distribution. All considerations of the reconstruction algorithms aim to minimize the errors, and to obtain quality images.Reconstruction of the conductivity distribution in electrical impedance tomography (EIT) is an un-determined and ill-posed problem. Typically requiring simplifying assumption or regularization methods to improve image quality.To improve the system’s conditioning and to determine the best image reconstruction in electrical impedance tomography (EIT) several regularization methods in this work are compared, and based on modification of the ratio between the largest and the smallest non-zero singular value of the sensitivity matrix, a new method has been developed.Also in this work a new method concerning electrical impedance tomography image registration has been developed and the full information contained in the new image can be obtained.
زينب احمد العزابى (2008)

Abstract The increased amount of electromagnetic radiation in the environment has increased the common concern over the possible health risks of wireless devices (e.g. mobile phone ). However, to minimize the amount of energy absorbed by the user is an advantageous from the technical point of view, as well. The reduction of power absorbed by the user not only reduces any possible health hazards but also makes the antenna more efficient. In this master’s thesis, interaction between modern mobile phone antennas and user is studied by using numerical full-wave EM methods. The thesis aims at improving, understanding how mobile terminal antennas behave in the vicinity of the user and how different numerical EM methods can be used to solve the interaction problem. The results give valuable information for antenna designers in order to design antennas which have low interaction with the user as possible. Furthermore this master’s thesis introduces a simple optimization technique to enhance the performance of planar inverted F antenna (PIFA) one of common modern mobile phone antenna in vicinity of user and reduce its effect on health.
محمد على المنصورى (2008)

Abstract In this thesis, we present a method for the design of multidimensional digital filters. This method is based on the use of genetic algorithm (GA). GA algorithm is proposed to optimize the coefficients of magnitude frequency response of digital filter design. GA algorithm is used to minimize a cost function representing the difference between the frequency response magnitudes of an ideal and obtained digital filters. Two types of filters namely, Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) are implemented.The digital FIR filter exhibits a wide transition bands and ripples in the pass band which are considered as disadvantages in digital image processing. Therefore, the only way to obtain a steep transition FIR is to use high order which translates to high cost. An alternative way to avoid high cost filters is to use IIR digital filters. Such digital filters can provide steeper transition bands with lower order than equivalent FIR digital filters. Although FIR digital filters have the disadvantages of high cost in term of hardware realizations, they have the advantage of stability and linear phase. Since IIR digital filters have infinite impulse response, they are prone to unstability. Linear phase which is easy to obtain in FIR digital filters is hard to come by IIR digital filters. The low cost and fast filtering make the IIR digital filters attractive. The proposed GA is utilizing for the design of stable IIR filter with near linear phase constraints. Experimental results are presented for 1-D and 2-D digital IIR filter. From the magnitude-frequency response, the convergence of the proposed approach will be able to obtain global minima in a faster time.
ميسون محمد الزرقاني (2010)