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نتائج البحث: 16 من أصل 116

تصميم وبناء منضدة عمليات طبية == THE DESIGN, CONSTRUCTION AND OPERATION OF A CLINICAL OPERATING TABLE

اسم المؤلف: محمد معن عبد الستار
اسم المشرف: Albert E.Yousif
الموضوع العام: الهندسة الطبية
السنة: 2008
الموضوع الدقيق: الهندسة الطبية
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:

نمذجة تقنية تفتيت الحصاة بالليزر == MODELING OF LASER LITHOTRIPSY TECHNIQUE

اسم المؤلف: وديان حميد رجه
اسم المشرف: منقذ سليم
الموضوع العام: الهندسة الطبية
السنة: 2008
الموضوع الدقيق: الهندسة الطبية
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:

انتقال الحرارة بالتوصيل في وسط مسامي بسبب مصدر حراري مركز == Conduction Heat Transfer In Porous Media With Embedded Concentrated Heat Source

اسم المؤلف: مظفر سوادي تايه
اسم المشرف: Ihsan y.Hussain
الموضوع العام: هندسة الميكانيك
السنة: 2008
الموضوع الدقيق: هندسة الميكانيك
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: The present study had been carried out to investigate the twodimensional transient heat conduction with internal heat generation in rectangular enclosure air - saturated porous media theoretically.The investigated geometry is rectangle and different type

الموقف القيمي لجماليات العمارة العراقية المعاصرة == The Valuation Attitude For Aesthetics In Iraqi Contemporary Architecture

اسم المؤلف: فرح احمد خضر
اسم المشرف: عبد الحسين العسكري
الموضوع العام: الهندسة المعمارية
السنة: 2008
الموضوع الدقيق: هندسة العمارة
الدرجة: ماجستير
اللغة: العربية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تعددت الدراسات المتعلقة بالجمال والجماليات المعمارية، كما تنوعت الحقول التي قامت بدراسة كل منهما، مثل الفلسفة وعلم النفس والاجتماع. فقد شغل الكثير من الفلاسفة بموضوع الجمال، واستمر البحث فيه وفي مصادره في مختلف العصور، وقد حاول علماء النفس والاجتماع وضع ت | Many studies were made about beauty and architectural aesthetics, as a variety of fields, which had studied each, such as philosophy, psychology and sociology. Beauty was always philosophers’ concern, and continued research it and it sources in various ages, psychologists and sociologists tried to find interpretations of the aesthetic experience according to their attitudes. The values were still the subject of research and study to this day. They were studied by philosophers, sociologists and psychologists and also by architects to see their influence on architecture. This research is a mere attempt to have a better understanding of the subject of beauty and its sources and its impact on the architecture and how to accept it and deal with it. From which the research’s problem appear which is the attempt to find the influence of the value situation on the architectural aesthetics of the Iraqi contemporary architecture. The research tries to combine the subjects of architectural aesthetics and values, and identifies the rule that values have in the matter of “aesthetic taste” for individuals and societies. Proceeding from the idea that beauty could be in subject or object or both, the research discusses the impact of values or values sequence in society on those two factors (subject and object). Thus the theses suggested to solve the research’s problem included the necessity of the value situation, which depends on not only philosophical bases but also social factors, to understand the architectural aesthetics; the second thesis included the importance of values’ situation to direct the “aesthetic taste”. The third thesis was says that due to the inconsistency of the political, economical and social situations in Iraq, a case of confusion in the aesthetic preference appeared, which requires finding the criteria to solve this problem.Values have different sources, their power and obligation increase according to the power of their sources. So in order to study these values the research went back to their sources to further understand them, then analyze their impact on the subjective and objective factors of architectural aesthetics. Chapter one of this study included the discussion of values, beauty, aesthetics and attitude, with a brief demonstration of their history and sources. While chapter two discussed architecture and it’s significance for society, then found that architecture carries the values of the society and thus it’s aesthetic sense, chapter two also gives a brief description of contemporary Iraqi architecture and the most important events that effected it. As for chapter three, there is a summery for all the information and conclusions made throughout the study and a subtraction of the main terms that form the objective and subjective characters of the architectural aesthetics, then they were put into comparism with the value situation to find their effect on aesthetics, then these relations were applied to examples of Iraqi architecture, the study found in the forth chapter that the relationship between values and aesthetics is strong, for both subjective and objective terms, because values are indicators and rules that society follow, and as long as the architecture follows these rules - values - it would be accepted by society and beautiful, and this is one of things that gives identity of architecture in a certain place and time The study also found that if the society was well connected and had strong and sacred values, its architecture will carry its identity and stands for its as well as all it’s arts.

الفيزياء والعمارة == Physics And Architecture

اسم المؤلف: ندى عزام محمود الحمداني
اسم المشرف: اريج كريم مجيد السدخان
الموضوع العام: الهندسة المعمارية
السنة: 2008
الموضوع الدقيق: هندسة العمارة
الدرجة: ماجستير
اللغة: العربية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تحقيق التوازن مع الطبيعة هو الهدف الذي تسعى اليه الجهود المبذولة من قبل العلماء والمصممين على حد سواء خصوصا مع المشاال المتزايدة التي تهدد عالمنا اليوم. وقد استغلت قوانين الفيزياء باعتبارها قوانين مستنبطة من الطبيعة من اجل تحقيق هذا الهدف ونتج عن ذلك ظهو | Achieving the balance with nature is the aim that all efforts of architectures and scientists trying to achieve especially with the increasing problems that threatened our world today. The laws of physics have been used as it is a law from nature to achieve that goal. resulting from that , the concept of sustainability that goes through all fields of life emerges to us with architectures like sustainable architecture, green architecture and Gaia architecture.The way to achieve sustainable architecture needs a full description to the relation between architecture and physics and goes in depth of this relationship.So the research general theses problem emerged that” there is few studies in complete vision about the concept of correlation between physical field and architecture from the theoretical concepts and the basic components that the concept embedded”. The minor thesis embedded that ”There is ambiguity in how to specify and act the physical laws by the designer and his interaction with it to give a touched result on the physical level “ , the research theses indicates “There is ambiguity in how to specify and act the physical laws in producing sustainable architecture”.The research aims to spot the light on this relationship between physical laws and architecture and examines its sustainability, and to make full use of natural laws available in our hands to produce sustainable architecture.The research structure has been built through 5 chapters : - First chapter : dealing with the intellectual theses and local studies that deals with the research problem “physics and architecture” to conclude the research problem and specifying the aim and methodology. - Second chapter : build a theoretical informational basis of physics and its relation with architecture, taking in consider the graduation and evolution of this relationship, and the main philosophical characteristics that reflected in architecture. - Third chapter : building the theoretical structure through polarizing the relation of physical laws with architecture so the special theses has been produced, which deals with the relation of physical laws with architecture, to conclude the variables that have beenexamined by applying them on a collected projects which is being agreed on its sustainability , so the research hypothesis has been formed and the final variables have been adopted as a measurable variables in the applied chapter. - Fourth chapter : specifying the way of measurements adopted and the definition of selected projects and making the practical study through applying the theoretical variables on an architectural projects. - First chapter : the final result of the study has been given , represented in : results correlated with theoretical structure , results correlated with practical side ending with the recommendations and future studies that grows from the research.The result of the study that the research has been reached to : is that the sustainable architecture is the architecture that achieves and embodies the physical laws on the theoretical, physical and functional level. Also the research has been reached to the following conclusions.

التجديد الحضري ومدينة الغد : دراسة تحليلية مقارنة في المدن التقليدية والمعاصرة == Urban Renewal And The Future City : A Nalytical Comparative Study In Traditional And Contemporary Cities

اسم المؤلف: نرجس حسين علي الجبوري
اسم المشرف: صبا جبار نعمة الخفاجي
الموضوع العام: الهندسة المعمارية
السنة: 2008
الموضوع الدقيق: هندسة العمارة
الدرجة: ماجستير
اللغة: العربية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تمتلك المدن التقليدية ذات الجذور التاريخية والتراث الحضاري ومنها مدننا العربية عموما ومدننا العراقية على وجه الخصوص , خصائص معينة ناتجة من ثوابت ومحددات بيئية وثقافية متمثلة بالخصائص المادية للمدن التقليدية وتشمل البيئية والاجتماعية والاقتصادية والجمالية | Cities have the traditional historical roots and cultural heritage, including Arab towns in general, and cities of Iraq in particular, certain characteristics resulting from the constant and the parameters of environmental, cultural form of physical characteristics of traditional cities include environmental, social, economic, aesthetic and non - physical characteristics of Others include intellectual, social, artistic, which gave its cultural identity And attribute them over time, it also faces great challenges in light of the evolution of modern and emerging challenges represented by these physical challenges, which include (population explosion and the crisis of transport and communications, pollution, energy consumption, technology, communications and information revolution) and non - physical challenges of others (the crisis of identity, alienation, globalization ), Which was a threat to these cities in civilization side and the future development. Therefore, research take urban design policies and methods with regard to urban renewal for the Future of Urban best of these cities and assimilate the age and its challenges, thus identified the problem of research the future development of cities with traditional historical roots and their attitude towards the immediate challenges of the age and the role of urban renewal policies in that. And define the research aims by providing knowledge on traditional cities with the historical roots by discussion over the physical characteristics and non - physical and put the challenges facing these cities to identify the most important urban renewal strategies best suited to the nature of these cities that represent the origins of Action for the future development of these cities. Assumed that the traditional cities of the historical roots of many of the constants and parameters relating to physical characteristics and non - physical characteristics for such cities as it faces significant challenges in light of the evolution of the times, therefore, the existence of a future vision for how those cities in the near future is a necessity for urban renewal policies and selection Most of which is key to the city's future and be absorbed by the immediate requirements of the age as a Predictive. The research methodology adopted analytical and descriptive in the theoretical framework, and practical framework has been selected five global examples (Arab and Western) that represent the cities of the future rooted historical and civilization heritage, The results showed the effectiveness of urban renewal policies in the future development traditional cities with historical roots and absorb solutions thereby realizing convoyed the age and preserve the cultural heritage and inspire cultural heritage at the level of details or potential sleeper, which is considered some of them as solutions to the challenges of the times, and the varying policies of urban renewal in accordance with the importance of Heritage area in addition to other factors, has focused on preserving areas of high architectural value with a flexible approach to preserving and reviving the architectural heritage and linking it with the whole city, and adopt a principled rehabilitation in areas of moderate architectural value terms allow for modifications and additions - run of the existing buildings to stimulate economic, social and cultural life, and adopt a principled urban infill in urban areas that have been rehabilitated vacant and destroyed spaces, the principles re - development, follows in areas outside the boundaries of traditional areas of inheritance Civilized, and revitalization follows at the level of a whole city, connecting the previous policies.

تقويم الموروث العمراني على وفق المواثيق الدولية : دراسة تحليلية للمركز التاريخي في الكاظمية == Rectification of Architectural Heritage According To International Conventions : Analytical Study of The Historical Center In Kadhymiah

اسم المؤلف: سماح عبد العزيز ابراهيم
اسم المشرف: مظفر علي الجابري
الموضوع العام: الهندسة المعمارية
السنة: 2008
الموضوع الدقيق: هندسة العمارة
الدرجة: ماجستير
اللغة: العربية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: تشكل عملية تقويم التراث جانبا مهما في عملية تحديد التراث ومعرفة الطرق الامثل للتعامل معه على اساس اهميته وما يحمله من قيم تراثية، ويمكن تعريف عملية تقويم التراث بانها عبارة عن مجموعة الاجراءات والاساليب والمؤشرات والمعايير التي تستخدم لتقييم وتحديد قيمة ا | Rectification of architectural heritage is an significant side in the process of selecting , listing , and dealing with cultural heritage according to it’s values and importance ,This process could be defined as the procedures and criteria used for evaluating heritage and knowing the advantages an disadvantages of the approaches of dealing with heritage based on the items mentioned in the international conventions ,which would help increasing the advantages and reducing the disadvantages in any future development projects.Heritage Rectification also helps knowing whether the cultural heritage property matches the international criteria and conditions of listing International Heritage and it’s ability to give a special identity to the culture of it’s country, facing the future changes and carrying the past generations’ message into the future generations.Although there are many studies related to heritage , but the divisions and types of heritage was rarely mentioned , so as for the criteria based on which some cultural heritage properties are to be considered as international heritage holding extraordinary values , and have a special protection by international organizations.Based on all of the above , the research is oriented to focus on the concepts , terms and criteria associated with listing and protecting cultural heritage, and the studying of significant experiences of dealing with heritage by international organizations including a city in Iraq , in order to make an approach of evaluating ,developing and protecting heritage ,and test it on the historical center in Kadhmyah old city , as a model of many other cultural heritage sites in Iraq.In order to achieve that ,the research is divided into three chapters , the first chapter deals with the main concepts and approaches associated with Architectural Heritage while the second chapter contains the main international conventions on heritage and studying and analyzing different experiences of protecting heritage , in order to conclude the terms and criteria of listing and protecting international cultural heritage and test them on the historical center in Kadhmyah city in the third chapter of this research , reaching into the conclusions and recommendations in the fourth chapter.

العمارة والازمة اثار الحرب في الانساق الحضرية == Crisis And Architecture Effects of War On Urban Patterns

اسم المؤلف: شيماء طلال عبود
اسم المشرف: اريج كريم مجيد السدخان
الموضوع العام: الهندسة المعمارية
السنة: 2008
الموضوع الدقيق: هندسة العمارة
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Crisis represents one of the most important factors that lead to radical changes in the city systems within a short period of time, and because of the war being one of the most important causes and results of a crisis; therefore war changes the city systems in different aspects.The war mechanism mainly depends on its destructive energy which affects directly the city systems, as well as its physical and symbolic components; nevertheless, the city constantly tries to balance itself by controlling its changing elements in the reconstruction process to form a new balanced state.A comprehensive theoretical framework capable of building integrated basic concepts about reconstruction of cities influenced by war and its effects on urban patternschange was absent in the literature.This have led to the creation of the basic research problem which is "the lack of a professional knowledge concerned with the concepts of city urban patterns and their changes during crises."Therefore, the aim of the research is to clarify the physical relation between war and the patterns of urban fabric. This will be done by studying the effects of the war massive destructive energy on the urban patterns through related literature such as chaos theory and its applications in mathematical field (fractal geometry) which will help in establishing a database concerned with the concepts of crisis, war, pattern, fractal and change. In order to accomplish this aim the research suggests a main hypothesis, which is "the war may demolish the fractal characteristics of the urban fabric by changing its patterns" and a secondary hypothesis "the reconstruction process plays a vital role in controlling the fractal characteristics of the urban fabric".The research structure comprises chapters discussing the research fundamental concepts by implementing a scientific analytical methodology and chaos theory since the war is an unpredictable state with high energy that follows non linear path and a wide range of probabilities.Chapter One comprises introduction and the literature review which is of great importance in determining research problem, aims, hypothesis, and methodology.Chapter Two discusses the nature of crisis and war by studying their types, conducts, mechanisms, and theories to extract the interrelationship between them; ultimately the chapter ends with discussing their damages to the system.Chapter Three discusses the nature of pattern and its changes by studying its components, types, mechanisms, and theories in order to recognize pattern's necessity for the continuity within the urban fabric.Chapter Four discusses the theoretical framework of war and pattern change by investigating how the crisis may deform the fractal properties of the urban fabric through transforming the existing physical patterns.Chapter Five is the practical application of the theoretical framework which tests a number of regional and international examples by applying the research hypothesi on a number of selected samples and finally proves the validity of the research hypothesis in Baghdad reconstruction proposal.Chapter Six finally ends the research with conclusions and recommendations to sustain the fractal characteristics of cities damaged by wars, through reconstructing structure from the beginning with the appropriate trends of reconstruction; otherwise the inevitable patterns that develop as a result will cut across the original fractal properties.

التحليل الثلاثي الابعاد للحفريات بطريقة العناصر المحددة وباستخدام انموذج السطح المحيط المرن اللدن == Three - Dimensional Finite Element Analysis of Excavation Using The Elasto - Plastic Bounding Surface Model

اسم المؤلف: فادي لؤي عبو
اسم المشرف: Qassun Sa'ad Al | deen mohammed Shafiqu | Raid R, Al | omari
الموضوع العام: الهندسة المدنية
السنة: 2008
الموضوع الدقيق: الهندسة المدنية
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Three - dimensional finite element analysis for excavation problems is conducted in this study to investigate the significance of three - dimensional analysis in these problems.A main computer program has been modified to perform the timedependent three

تحليل الالواح السميكة المستطيلة المسندة على اسس مرنة ذات المعاملين == Analysis of Thick Rectangular Plates on Two Parameter Elastic Foundations

اسم المؤلف: تقى وليد احمد
اسم المشرف: Riyadh J.Aziz
الموضوع العام: الهندسة المدنية
السنة: 2008
الموضوع الدقيق: الهندسة المدنية
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ھذا البحث يتعامل مع السلوك الخطي للصفائح السميكھ المسنده على اسس مرنه ذات معاملين. نظرية مندلن للوح السميك تم توسيعھا لتشمل تاثير استناد اللوح على اسس مرنه ذات معاملين.(Filonenko - تعتبر مشاكل الالواح السميكھ المسنده على اسس مرنھ ذات معاملين من التطبيقات | This research deals with the linear elastic behavior of thick plates resting on two parameter elastic foundations. Mindlin’s thick plate theory is used to include the effect of two parameter elastic foundation.As an application; the problems of thick pla

تقليل الاعاقة في الجريان المضطرب باستخدام البولي اكريل امايد وصمغ الزانثان : دراسة عملية ونظرية == Turbulent Drag Reduction By Polyacryl Amide And Xanthan Gum, Experimental And Theoretical Investigation

اسم المؤلف: احمد عدنان عطشان
اسم المشرف: جبار شنشول جمالي
الموضوع العام: الهندسة الكيمياوية
السنة: 2008
الموضوع الدقيق: الهندسة الكيمياوية
الدرجة: ماجستير
اللغة: الانكليزية
النص الكامل من المصدر: https://nahrainuniv.edu.iq/sites/default/files/THESIS_8.pdf
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: This work presents an experimental study of the drag - reduction performance of two water - soluble polymers, Polyacrylamide(PAAM) as flexible, linear synthetic polymer and Xanthan Gum(XG) as a rigid polysaccharide from natural resources. The flow loop used consisted of 0.5 O.D. inch straight pipe with a test section of 3 m length. A 0.5 inch O.D. vertical tubing with elbows was also included to compare the drag - reduction behavior between both tubing configurations. Various concentrations of polymeric additive and water flow rates were tested. The results show that the drag - reduction in vertical piping are significantly lower than in straight type for both polymer type. The dragreduction efficiency of Xanthan Gum agent is much lower than polyacrylamide. Higher concentrations of XG about 150 ppm is required to get exactable drag - reduction performance about 12.84% in the straight pipe. While about 40.3% drag - reduction was achieved with about 50 ppm Polyacrylamide with the same conditions. Moreover, the drag - reduction efficiency of XG can be improved by mixing with Polyacrylamide agent at a given conditions.Part of the experimental work was devoted to study the performance of Polyacrylamide as drag - reducing agent with the existence of small amounts of sodium chloride acts as an inhibitor to the ability of the additive, resulting in lower drag - reduction probably due to collapse of PAAM at more compact structure with the addition of sodium chloride as strong ionic salt.Polyacrylamide and Xanthan Gum additive undergo undesirable mechanical degradation with increasing of circulation time, leading to lower drag - reduction performance. The molecular degradation is likely to occur at low additive concentrations and low turbulence flow, in vertical piping, since the polymeric additives are exposed to shear stresses.Further attempt was done in present investigation to find correlations for accurately predicting drag - reduction characteristics of drag - reducing agents, used in published works. A published time scale hypothesis for prediction of drag - reduction values, the friction factor data as a function of the polymer concentration, shear stress, Reynolds number, pipe diameter. The experimental friction factor results were taken from a published work for gas oil with polyisobutylenes. Good agreement between measured and predicted friction factor. Further attempt was made to correlate the mechanical degradation ability by modifying the Kouraush, Williams and Watt (KWW) equation. The experimental data were taken from a published work for Polyethylene Oxide. The modified equation was found to fit experimental data better than the original KWW equation.

استخراج الطرق اعتمادا على تقنية الافاعي المنطادية == Road Extraction Based on Balloon Snakes Technique

اسم المؤلف: فراس فاهم عبد الحسن الصكبان
اسم المشرف: محمد احمد المشهداني
الموضوع العام: هندسة الحاسبات
السنة: 2008
الموضوع الدقيق: هندسة الحاسبات
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: ان استخراج الطرق من الصور الجوية وصور الاقمار الصناعية يؤدي دورا مهما في رسم الخرائط وتخطيط يحتاج الى تحديث سريع للطرق (GIS) شبكات الطرق الجديدة. ان التطور الحالي في نظام المعلومات الجغرافية في كل ارجاء الكوكب.خلال العقود الاخيرة طورت الكثير من الطرق الا | The extraction of roads from aerial and satellite images is an important task within cartography and planning of new road networks. The recent developments of the Geographic Information System (GIS) require rapid updates of roads all over the planet. Over

تحليل الاتصال بين القمر الصناعي والطائرة باستخدام نموذج تعقب الشعاع == Analysis of Satellite - To - Aircraft Communications Using Ray Tracing Model

اسم المؤلف: علي محمد علي
اسم المشرف: جابر سلمان عزيز
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: While the aircraft flying above the earth surface, the signal transmitted from the satellite to the aircraft suffered from changes in it's characteristics at the aircraft receiver's antenna according to many factors affecting the direct and reflected power from the earth surface such as the distance difference, the nature of the earth surface, elevation angle, Doppler shift, etc… This Thesis introduces a proposed algorithm to analyze and simulate the communication link between the Satellite and the aircraft taking into account all the parameters that affect the magnitude of the power and signal characteristics received at the aircraft antenna. The proposed method uses the ray - tracing technique in this simulation to analyze the communication link between the Satellite and aircraft. The simulation developed in this thesis has minimized the error percentage as much as possible taking into account most of the factors that might affect the characteristics of the signal received by the aircraft from the satellite. This simulation considers the free space loss, specular reflection losses, scattering factor, earth curvature effect, etc…,also the simulation takes into account the Doppler effect that caused by the aircraft movements. The simulation measures the received signal strength and fading characteristics of satellite to aircraft communication to determine the effectiveness of communication and to establish parameters which can be useful to the communication system designer in Iraq and the rest of the world. MATLAB® v6.5 used in the simulation as application software, the simulation also applied to MATLAB® v7.0.

محاكاة تضمين تقسيم التردد المتعامد المتعدد المستخدمين المشفر في الخط النازل == Simulation of Coded Multiuser Ofdm Downlink

اسم المؤلف: دﻧﻴﺎ ﻓﺆاد فاروق النعيمي
اسم المشرف: رعد سامي فياض
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: The orthogonal frequency division multiple access (OFDMA) scheme adopts orthogonal frequency division multiplexing (OFDM) subcarriers, which are particularly suited for transmition over broadband frequency selection channels, to support multiusers. The scheme considered usually assigns a subset of subcarriers to each user and adopted adaptive techniques for the allocation of available resources/subcarriers according to the channel state information (CSI) estimated at the transmitter using a reverse link. This thesis proposed three coded multiuser OFDM schemes based on spreading the data of each user over all subcarriers without CSI at the transmitter. The idea behind these schemes is to split the OFDM transceiver into two stages : one common to all users while the other consists of identical parallel units with each unit is used to process the data related to an individual user. The two stages are separated by a multiplexer/demultiplexer unit whose position can be chosen to yield different schemes. The three schemes considered here are : user multiplexed scheme, inner coded multiplexing scheme, and mapper multiplexing scheme. The proposed schemes implemented are using MATLAB simulink (version 7) to investigate their performance under different operating conditions related to number of users, Rayleigh fading channel, and serial concatenated codes. The results are compared with those related to two conventional schemes, subcarrier mapping scheme and outer coded multiplexing scheme. The simulation results indicate that the proposed user multiplexing scheme may offer performance as high as that offered by the conventional outer coded multiplexing scheme but with reduced number of equipments.

تهيئة حاسوبية لموجه سيسكو == Computer Based Configuration For Cisco Routers

اسم المؤلف: فارتان رافي كريكوريان
اسم المشرف: غسان حميد عبد المجيد
السنة: 2008
الموضوع الدقيق: هندسة الاتصالات
الدرجة: ماجستير
اللغة: الانكليزية
مكان الجامعة: بغداد
الصفحات الاولى:
المستخلص: Routers are intelligent devices that make connection between different networks possible. In addition, routers can perform several functions, including filtration and selection of the best path of packets movement. Routers must be configured efficiently in order to perform the above functions. In literature, two approaches have been distinguished for the configuration, namely; text mode and graphical mode approach. The present work is analyzing these two approaches and defines precisely their advantages and limitations. As a result of this analysis, a new approach is proposed in this thesis which eliminates the limitations. The work proposes a graphical interface which is executed on a desktop (or laptop) PC. The user defines the configuration parameters through a program which transfers these parameters to the router by console port instead of Ethernet port. These parameters are then saved on Non Volatile Random Access Memory. The proposed graphical interface is implemented by standard lab consisted of two routers. The implementation shows that the time of configuration can be reduced to 70% of the text mode approach, and overcome the trouble of the old graphical interface.
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