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bsj-7050
Reducing the Mutual Coupling of Cylindrical Circular Microstrip Antennas (CCMAs) Array Using EBG Structure
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A theoretical study to design a conformal microstrip antennas was introduced in this work. Conformal microstrip antennas define antennas which can be conformed to a certain shape or to any curved surface. It is used in high-speed trains, aircraft, defense and navigation systems, landing gear and various communications systems, as well as in body wearable. Conformal antennas have some advantages such as a wider-angle coverage compared to flat antennas and low radar cross-sectional (RCS) and they are suitable for using in Radome. The main disadvantage of these antennas is the narrow bandwidth. The FDTD method is extremely useful in simulating complicated structures because it allows for direct integration of Maxwell's equations depending on time. The 1x2 cylindrical circular microstrip antennas array is designed and simulated vertically via Finite Difference Time Domain (FDTD) method where can directive antenna be achieved through antennas array design. Mutual coupling between the antennas in the array and the different separation between them were studied. The circular patch is excited by a probe feed method for several reasons including providing less spurious radiation from the probe current, in addition to the simplicity in theoretical engineering installation and practical manufacturing. It is well known that the values of the coupling are decreased as the distance separation increased. Cylindrical circular microstrip antenna with resonant frequency operating is 3.5GHz for  mode, several parameters like return loss, band width, and input impedance are calculated. Also, for isolated coupling, mutual coupling coefficients, directivity gain, for different separations between the centers of the two adjacent circular patches in terms the wave length operating are calculated. Moreover, the electromagnetic band gap EBG structure is used for reducing the mutual coupling created by the surface waves in order to enhance the antenna's performance in an array has become smaller than before. The proposed EBG is a three triangular-shape equal sides metallic structure, utilizing the inter-element spacing in an array. The less value of   for the spacing between the two centers of patches is . BW percentage increased to 34.3% and the directivity is enhanced also.  Additionally, simulations were done using MATLAB 2017b.

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Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مستقبل الصناعة العربية في ظل اقتصاد عالمي متغير
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أن التطور الاقتصادي  في أية دولة إنما يقاس بالدور الذي يلعبه القطاع الصناعي في اقتصادياتها، ومقدار ما يسهم به في الناتج المحلي الأجمالي. ولا يخفى أن ينسب ذلك إلى خصوصيات هذا القطاع بوصفه الميدان الذي تتحقق فيه انجازات الثورة العلمية والتكنولوجية أكثر من غيره من الميادين، وأرتباطاته الأمامية والخلفية مع سائر القطاعات. يضاف إلى ذلك أن القطاعات الأخرى تتأثر ايجاباً بنمو القطاع الصناعي، كما انه المسؤول

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Publication Date
Tue Mar 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Laplace Distribution And Probabilistic (bi) In Linear Programming Model
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The theory of probabilistic programming  may be conceived in several different ways. As a method of programming it analyses the implications of probabilistic variations in the parameter space of linear or nonlinear programming model. The generating mechanism of such probabilistic variations in the economic models may be due to incomplete information about changes in demand, pro­duction and technology, specification errors about the econometric relations presumed for different economic agents, uncertainty of various sorts and the consequences of imperfect aggregation or disaggregating of economic variables. In this Research we discuss the probabilistic programming problem when the coefficient bi is random variable

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
أنتاج الفقر في الدول النامية بين المفهوم والأسباب
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The poverty in the developing countries is output to under development as we consider welfare, where as when the poverty disappear that produced be the general development . Historically, in our countries, the underdevelopment is the result of colonialism period and what is associated with it of transferring the surplus abroad  and the disorder of production structure.  And at the present  time, the poverty is reproduced and aggravated in the last years as a result of many  internal and external reasons.Today, poverty is associated in many forms with the poverty previously.

 

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Publication Date
Thu Mar 01 2007
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة الأساليب المستخدمة في تحديد عدد المركبات الرئيسية مع التطبيق العملي
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The principal components analysis is used in analyzing many economic and social phenomena; and one of them is related to a large group in our society who are the university instructors. This phenomenon is the delay occurred in getting university instructor to his next scientific title. And as the determination of the principal components number inside the principal components depends on using many methods, we have compared between three of these methods that are: (BARTLETT, SCREE DIAGRAM, JOLLIFFE).

     We concluded that JOLLIFFE method was the best one in analyzing the studying phenomenon data among these three methods, we found the most distinguishing factors effecting on t

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Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
العدالة التنظيمية في إطار إدراكات العاملين (دراسة ميدانية)
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يهدف هذا البحث الى تحديد اثر الاختلاف في ادراكات العاملين للعدالة التنظيمية في المنظمات قيد البحث. وقد تم اعتماد الادراك كمتغير تفسيري، اما العدالة التنظيمية فمثلت المتغير الاستجابي بانواعها الثلاث (العدالة التوزيعية، العدالة الاجرائية، والعدالة التفاعلية)، ولتحقيق اهداف البحث فقد تم اختيار دائرة صحة بغداد/ الكرخ مجتمع للدراسة. وجرى تصميم استبانة ووفق مقياس خماسيي الدراجات وجرى تحليل البيانات باستخ

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Publication Date
Sat Mar 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
رؤية تشخصية للمجتمع المعرفي في ظل اقتصاد المعرفة
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يهدف هذا البحث الى عرض رؤيا تشخصيه لمجتمع المعرفة في ظل اقتصاد المعرفة من خلال استعراض العديد من المفاهيم النظرية والعلاقة بينهم كمفهوم البيانات والمعلومات والمعرفة ومجتمع المعلومات والمعرفة, ومصادر المعرفة, والمراحل التطورية للتحول الى مجتمع المعرفة, ومن ثم استعراض الأبعاد الأساسية لمجتمع المعرفة, إضافة إلى الملامح الأساسية لاقتصاد المعرفة وخصائص ذلك الاقتصاد, ثم تناول البحث المورد المعرفي وعلاقته

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Publication Date
Sat Dec 29 2018
Journal Name
Journal Of Planner And Development
دراسة تحليلية للمناطق الخضراء وأثرها في بيئة المحلة السكنية )منطقة الدراسة محلة 405 في الكاظمية)
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Publication Date
Mon Dec 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
ظاهرة العاملين المؤقتين ( الدور المتنامي في ظل العالمية)
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The research intended to take into consideration the phenomena of employing the temporary employees through the business organization increasingly, which has become one of the most apparent features of the contemporary strategy of the human resources management. It depends on the analytical descrptive Approach to meet the research problem which has been focalized around the dispute praising regarding the phenomena of the temporary employment and its dimensions and challenges which can be faced by the management of human resources as a result .The importance of the research is represented as one of rare research which confronts to the phenomena of the temporary employment in the Iraqi business environment. The most prominent objec

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Publication Date
Fri Jun 30 2023
Journal Name
Journal Of The College Of Islamic Sciences
الصورة الفنية للأزهار في شعر ابي وكيع التنيسي
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ارتبط الانسان بالطبيعة بأشكالها المختلفة ارتباطا وثيقا ، فهي تمثل الحاضنة له بمجالات حياته كلها، فما كان من الأدباء الا أن يجعلوها في كثير من الأحيان مادة لأدبهم وأرضية خصبة لنتاجهم، فتمظهرت بصورها المختلفة وحاجة الانسان لها وخيرها وشرها في الأدب على مدى التاريخ، والعرب شأنهم شأن غيرهم من الأمم فمنذ عصر ما قبل الاسلام كانت الطبيعة منفذا مهما وملجأ للشعراء في انتاج الأدب وابداعه وإلى يومنا هذا، ونحن إذ نتحد

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Publication Date
Sun Jan 01 2012
Journal Name
Journal Of Educational And Psychological Researches
الصعوبات التي تواجه البحث العلمي في جامعة بغداد من وجهة نظر التدريسيين
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The problem of the study lies in the need for standing on the justifications, reasons and difficulties that face the scientific research matter at Baghdad university. The importance of this study lies in the fact of being scientific research one of the most important methods in developing the teaching members performance efficiency which contributes in teachers contact with the modern developments that emerge in work. That matter which reflexe on the educational process and the scientific production in their universities.

And the research goal is summarized in identifying the difficulties that is facing the scientific research at Baghdad university from the point of view of the lecturers, and also to ide

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