البحث — المستودع الرقمي العراقي

المستخلص: المحـــــــــــول الخافـــــــــض للــــــــــــفولتيـــــــــة المستمرة ذو المكثف المفـــــــتاحــــــــي (Switched Capacitor DC - DC Converter ) يمكن ان يستعمل للتحويل الكفوء للطاقة حيث نجد انه عندما لا تستعمل المحاثات في دوائر التحويل يؤدي الى خفض حجم | Switched - capacitor (SC) - based step - down DC - DC converter can be used for efficient power conversion when inductors are not used in order to reduce size and cost. In addition, switched - capacitor DC - DC converters are superior to inductor - based converters for high - conversion ratio and wide range of load variation. In this thesis , a multistage current - controlled switched - capacitor step - down DC - DC converter is analyzed , designed and simulated. The converter features are of good regulation capability and continuous input current waveform when two step - down converter cells are connected in parallel and operate in antiphase. Classical SC converter with pulse width modulation technique is also analyzed, designed , simulated. For the PWM converter and current - controlled converter , third - order state - space averaging technique is used for analysis. A fuzzy logic controller is used with the current - controlled converter to obtain fast dynamic response, low ripple in the output voltage and robustness against load and supply variations. A 70W ,48/12V and 12.5W 48/5V converters are designed and simulated ( Matlab/Simulink is used for simulation). The simulation results are obtained and compared for the above converters with different control techniques (PWM ,current control with PI controller and current control with fuzzy controller). The results for current - controlled converters with fuzzy controller show higher efficiency , lower ripples in the output voltage ,fast transient response, good disturbance rejection and very small steady state error of output voltage. In this thesis the value of the output ripple must less than 0.05 V and the efficiency should be more than 75 % for current control mode

ترميز القناة المرتكز على الاشارات الفوضوية == Chaos Based Channel Coding

اسم المؤلف: سراب كمال محمود

اسم المشرف: حكمت نجم عبد الله

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: الجامعة المستنصرية - كلية الهندسة - قسم الهندسة الكهربائية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

تقييم اداء نظام الاتصالات المتعدد المستخدمين المرتكز على متجهات فوضوية متعامدة == Performance Evaluation Of Multiuser Communication System Based On Orthogonal Chaotic Vectors

اسم المؤلف: بسمة نزار ناظم

اسم المشرف: ماهر خضير محمود

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: الجامعة المستنصرية - كلية الهندسة - قسم الهندسة الكهربائية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: In DS - CDMA systems, the use of orthogonal spreading codes with low cross - correlation values is needed to suppress the effect of multiple access interference (MAI) which increases as the number of active users in system is increased.Currently, the conventional PN sequences, such as (Gold codes, Kasami codes …etc.), generated by linear feedback shift registers (LFSRs) and orthogonal variable spreading factor (OVSF) were used as spreading codes in DS - CDMA system. Using these sequences, it is not possible to increase the number of active users in the system due to the fact that the possible sequences generated in conventional PN - system are limited in number and offer mutual interference as the number of active users is increased due to its non - zero cross - correlation values. The chaotic system can be used to generate very large number of quasi - orthogonal sequences compared with the number of PN sequences due to its sensitivity to initial conditions. Another type of chaotic sequences with zero values of cross - correlation called Orthogonal Chaotic Vectors (OCVs) is generated using chaotic systems and the basic idea of Gram - Schmidt ortho - normalization process.In this work, the use of OCVs in synchronous DS - CDMA system for transmission of data over (AWGN, Flat fading and Frequency selective channels) is introduced. The simulation results show that the DS - CDMA based on OCVs gives better BER performance when spread factor ? is greater than the number of active users due to the reduction of MAI between active users.Results show also that, at BER = - in AWGN channel and for 5 users, there are gain of (0.3, 1.2, 1.75 and 3.75) dB between system based on OCVs and systems based on small set Kasami sequence, Gold codes, large set of Kasami sequence and Non - OCVs respectively. Under the effect of flat fading channel, it can be noted that at BER = - and for 30 user, there is 1.7 dB gain between system based on OCVs and system based on small set of Kasami sequences, and this gain increases to 2 dB for 50 user.Under time invariant frequency selective fading channel and for 8 users at BER= - there is about 6dB gain between the system based on OCVs and system based on Non - OCVs.

تصميم وتنفيذ منظومة تعقب شمسي مستقلة معتمدة على نظام تحديد المواقع العالمي == Design And Implementation of A GPS Based Stand - Alone Solar Tracking System

اسم المؤلف: احمد جبار عبد

اسم المشرف: Fawzi M. Al | Naima

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: دكتوراه

الجامعة: جامعة البصرة

اللغة: الانكليزية

مكان الجامعة: البصرة

الصفحات الاولى:

المستخلص: In a step to overcome the limitations of sensor based solar tracking system, a design tracking strategy, is presented in this thesis which is based on astronomical equations. This strategy takes two important factors into consideration. The first is finding the more accurate equations and figure out the ability of implementing such system which can deal with these complicated equations that are based mainly on trigonometric functions. The second is how to design and build a reliable, uninterrupted, accurate and global system that is able to calculate the local time, date and location in terms of longitude and latitude.This thesis aims to design and implement practically a global dual axis solar tracker that can process the data with high efficiency, able to solve these complicated equations, gather the required data from the GPS card, then save, and manage them inaccurate with tracking efficiency up to 99.33%, increases the power production by over 40%, reduce the drive power requirement 31%, reliable and uninterrupted with real time controller.The system also presents a design for a hybrid network for a solar tracking farm consisting of N - solar tracking systems. A main control unit is presented to manage all the trackers to the sun location in multi - tracking mode, diagnosis all the trackers for any faults and give complete information about the produced power from each of the solar tracking system. A new network protocol is designed to deal with the error control, congestion control and flow control for data transmission in the network.A complete solution for power - line communication modem has been proposed based on existing power line characteristics. This modem has advantages of simplicity, cost effectiveness and using new strategy to control the out of reach devices without increasing the transmitting power or changing the circuit specifications. The proposed design offers a simple solution to control the solar trackers in a vast solar farm, enabling to monitor the supplied power by each single tracker in the field and having the ability of fault diagnosis.

تصميم وتنفيذ رادار تضمين التردد ذو الموجة المستمرة لنظام السرعة التكيفي للسيارات == Design And Implementation of Frequency Modulation Continuous Wave Radar For Adaptive Cruise Control of Car Applications

اسم المؤلف: تمارا زهير فاضل

اسم المشرف: منال حمادي جاسم

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكهربائية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: The traffic accidents became significantly obsession and concern for all members of society, and has become one of the most important problems that sap physical, human resources and human potential. The researches show that the damaged property and other costs may equal 3% of world’s gross domestic product, which have been required to work in finding solutions and suggestions and put them into practice to reduce these incidents.The insertion of preventive safety applications into the car system can avoid the above mistakes. In this work, a design and implementation of Frequency Modulation Continuous Wave (FMCW) radar system working at 77GHz for Adaptive Cruise Control (ACC) technology is proposed. Using MATLAB R 2013 which is a flexible system to estimate the speed and distance in accordance to vehicle ahead, which reduces the forces on the rate of accidents by warning the driver when two vehicle become too close.Also, the principle of FMCW radar is presented to generate Linear Frequency Modulated Continuous Wave (LFMCW) sweep waveform through frequency bands with triangular frequency modulation using Voltage Control Oscillator (VCO), a triangle sweep pattern adopt will resolve ambiguity without Doppler processing. which improves the decision making before hardware implementation.Proteus Professional v8 and Micro C PRO v 6.1 compiler is used for Peripheral Interface Controller (PIC) to design a proposed collision warning circuit with PIC16F887 and RS_232 serial port to send data using USART terminal for (short, middle, large) test range.A serial communication interface is used for sending the simulation results from MATLAB FMCW radar system to hardware easy PIC v7 board with PIC16F887 to forward collision warning circuit to alerts the driver of collision risk, Liquid Crystal Display (LCD) shows radar status (short, middle, large) in accordance to range between the vehicle that FMCW radar installed and the vehicle ahead.Graphic Liquid Crystal Display (GLCD) shows the car position and road lines. Piezo Buzzer will start singing to alerts the driver from danger road.The simulation design is achieving the desired performance, one parameter warrants further attention. In the FMCW configuration, the sweep time is about 25 microseconds. Therefore, the system needs to sweep a 140 MHz band within a very short period. Such an automotive radar may able to meet the cost requirement.

تقييم اداء الكشف المباشر والمتشاكه في نظام اتصال الليفة الضوئية == Performance Evaluation of Direct And Coherent Detections In Optical Fiber Communication System

اسم المؤلف: علاء عبد الزهرة جعفر

اسم المشرف: علي يوسف فتاح

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: الجامعة التكنولوجية - قسم الهندسة الكهربائية

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: تطورت خدمات الاتصالات بشكل متسارع في السنوات القليلة الماضية خصوصا في المسافات بعيدة المدى وبمعدل نقل البيانات بدقة عالية وخسائر قليلة في جميع انحاء العالم. وقدمت تقنيات مختلفة لزيادة سعة الارسال في انظمة اتصالات الالياف الضوئية بواسطة جمع مسارات البيانا | In recent years, there has been an extensive development of optical fiber services. They provide transmission over long distances at a high data rate with few losses all over the world. Different techniques have been introduced to increase the transmission capacity of optical fiber communication systems by a multiplexed high data rate stream into an optical fiber such as Dense Wavelength Division Multiplying (DWDM) technique. Since the deployment of DWDM technique, the focus on introducing large system capacity with high system performance, different detection techniques have been introduced to enhance the system performance with high sensitivity. In this work, two types of detection techniques (direct and coherent detection) have been evaluated and compared with each other. These detection techniques have been evaluated based on several models of encoding format such as Return to Zero - Differential Phase Shift Keying (RZ - DPSK) and Non Return to Zero - Differential Phase Shift Keying (NRZ - DPSK) at 10 Gb/s as a data rate.These systems were first simulated with a single channel to analyze the performance with no Stimulated Raman Scattering (SRS), Cross Phase Modulation (XPM) and Four Wave Mixing (FWM) effects. Whereby the system of 8×10 Gb/s is simulated at 200 GHz, 100 GHz and 50 GHz as channel spacing. Three types of dispersion compensation schemes are used in the link channel. These systems are simulated using (Optisystem version 10.0) software package. The performance of the designed systems are evaluated through Q.factor verses input power and Bit Error Rate (BER) verses Signal to Noise Ratio (SNR).The polarization interleaving is used with the WDM systems to decrease the nonlinear effects and the crosstalk arising among the adjacent channels.The obtained results of the 67% RZ - DPSK arrived to the threshold power at input power less than of the 50% RZ - DPSK, as well as the 50% RZ - DPSK system arrived to maximum Q.factor lower than 33% RZ - DPSK. This is due to the pulse duration of 33% RZ - DPSK is smaller than of 50% and 67% RZ - DPSK.The results show that the coherent detection technique has better performance than the direct detection technique. The coherent detection technique has Q.factor equal to 45, while the direct detection has Q.factor equal to 27 at the same input power ( - 5dBm), while the coherent detection technique arrived to the threshold power at the input power less than of the direct detection technique.The BER of the 33% RZ - DPSK with coherent detection with 10 Gb/s at 300 km as transmission distance achieved ?10?^( - 12.9) at SNR of 10 dB, while for the 33% RZ - DPSK with direct detection is achieved a BER of ?10?^( - 8.8) with SNR of 10 dB.The performance of the proposed systems has been improved extrusivly with increase the space channel, where the performance of the systems at 200 MHz as channel spacing has best performance than 50 MHz as channel spacing.By adapting coherent detection with 33% RZ - DPSK technique of 200 MHz as channel spacing, DWDM system can carry high data rate with long - haul transmission distance.

مراقبة انذار المرضى عن بعد الزمن الحقيقي اعتمادا على الصحة الالكترونية الصحة العنكبوتية الصحة الخلوية وشبكات التحسس اللاسلكية حالات الدراسة موضع منام المريض سكر الدم استجابة الجلد الكلفانية والتخطيط العضلي == Remote Patients Monitoring / Alarming In Real Time Based On E - Health / I - Health / GSM - Health And WSN, (Case Study : PP, BG, GSR And EMG

اسم المؤلف: علي جاسم رمضان

اسم المشرف: سمير جاسم محمد | محمود شاكر نصر

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: جامعة بابل - كلية الهندسة - قسم الهندسة الكهربائية

اللغة: الانكليزية

مكان الجامعة: بابل

الصفحات الاولى:

المستخلص: Patient's health monitoring / diagnosing systems have become the focus of attention of researchers today. At the present time, the researchers are dealing with the E - health fields to develop and improve the healthcare systems and they work to combine the GSM and Internet technologies together.In the presented work, the researcher designed a portable real time wireless medical system for monitoring / diagnosing the patients' status based on E - health / GSM - health / I - health and wireless sensor network (WSN) under ZigBee protocol, and to support alarming and printing of medical reports subsystems.The presented system consists mainly of four subsystems, which are sensing & data transceiver, base station (BS), GSM and Internet. Where sensing & data transceiver subsystems be in the patients' lobbies and connected remotely with the base station (BS) subsystem in the wireless sensor network that collect and display the sensing data in it. Also in the designed system, the GSM and Internet technologies are inserted practically in the network.The implemented system measures the biomedical data utilizing a group of sensors that are not available in the country's hospitals in such integrated system, which are the patient position sensor (PPS), galvanic skin response sensor (GSR), blood glucose sensor (BGS), and electromyography sensor (EMG). Moreover, the system has the ability to add many other sensors.In the proposed system, three nodes (lobbies) are considered according to the facilities available, but it can monitor / diagnose unlimited patients' numbers.The system monitors the sleep position and skin conductance (indicator to patient's calm) of the patients in real time with alarm for each abnormal case in the base station (BS) and in lobbies, and it also follows up the glucose rate in patient's blood and diagnose the electromyography (muscle and nerve) status.The GSM subsystem (GSM - health) is used for remotely following - up the patients' status by sending SMS alarm in time for any abnormal case of the patient's sleep position and skin conductance, also it has ability to send the glucose data to doctor's phone. All these services are performed by using a personal phone device only without using any additional GSM modem or other apparatus, so this method reduces cost, complexity and delay time of the system that's done by interfacing the phone with the PC directly via USB port and the messages sending procedure executed using special SMSs AT commands, so the doctors become able to communicate with BS using SMS or voice calling to give the fast and direct necessary guidance.The Internet subsystem (I - health) is another excellent service for the presented system, by which remotely following - up the glucose levels by uploading the glucose data to a specific web site. It is performed by designing a web site that is programmed using VB.NET and ASP.NET languages. of course, user login feature is added to protect the privacy of patients and feedback comments feature between the doctors and patients to take the important guidance.The system has ability to introduce a printed hard copy report about the patient's electromyography status or result and blood glucose levels, by utilizing VISUAL BASIC program. Moreover, it performs searching process about the active nodes in network, this means that it detects any new node (new patient) and put it in service. In addition, the system records the patient's information and stores his health data for any archiving process or statistical study.The main hardware that is used in the implemented system includes MCUs, sensors and transceivers, and used the LABVIEW program to display the data in its GUI windows in the computer of BS.The system has been implemented practically at low cost and low power, gave expected and accurate results, and presented to the specialists doctors and they have expressed their conviction and effectiveness of the system in practice.

تصميم وبناء هوائي عريضة الشريط باستخدام المواد المسماة مابعد المادة == Design And Implementation of Ultra - Wideband Metamaterial Antenna

اسم المؤلف: مروه مكي حمد

اسم المشرف: طه احمد عليوي | سليمان مرتضى عباس

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: جامعة بغداد

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

تجزئة الحزمة لالغاء الضوضاء المتكيف في تنقية الاشارة الكلامية == Subband Decomposition For Adaptive Noise Cancellation In Speech Enhancement

اسم المؤلف: حوراء فاضل عبيد

اسم المشرف: منال جميل الكندي

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: جامعة النهرين - كلية الهندسة - قسم الهندسة الالكترونية والاتصالات

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: Nowadays speech processing methods are usually implemented in the time or frequency domain. Filter bank can be considered as a divide and conquer approach within signal processing, since large problems are sub - divided into many smaller problems. While filter banks are essential components of speech processing, and in signal processing in general, they will have the focus in present days. An adaptive filter is a filter that self adjusts its transfer function according to its optimizing algorithms. Least mean square algorithm has slow convergence when used with nonstationary signals like speech and it has high computational cost but normalization of step size (or input signal) leads to a useful variant of the LMS algorithm known as the normalized LMS (NLMS) algorithm, which gives better convergence characteristics than the LMS because it uses a variable step - size with respect to the input signal power.To improve the convergence rate and/or computational complexity and also to overcome the disadvantage of a full band adaptive filtering, a structure is illustrated that is subband adaptive filtering; this will converge faster at a lower computational cost for speech and white noise inputs.This research shows most types of subband decomposition structures and makes comparison among them based on their performance to cancel the noise with minimum computational complexity, maximum convergence speed and maximum noise cancellation with lowest delay.Moreover three new hybrid tree configurations or the tree decom - position are proposed to maximize the overall performance of adaptive noisecancellation system.They are given the abbreviations HTPSAF1,HTPSAF2 and HTPSAF3. These three systems use polyphase filter bank that has showed a noticeable increase in the convergence speed and large reduction in the computational complexity due to the lower number of coefficients that can be achieved for the analysis/synthesis filters, which in turn will result in minimum delay in the reconstructed output speech signal.The algorithm of subband decomposition structures has been described theoretically then modeled under MATLAB simulation program using built - in filters and real input signals.

تصميم وتنفيذ منظومة مقاييس متوزعة ذكية == Design And Implementation of A Smart Distributed Metering System

اسم المؤلف: مهند غازي خميس

اسم المشرف: عدي عبد اللطيف عبد الرضا

الموضوع العام: هندسة الكهرباء والالكترون والاتصالات

السنة: 2014

الموضوع الدقيق: هندسة الالكترونيك والاتصالات

الدرجة: ماجستير

الجامعة: جامعة بغداد

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى: