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jeasiq-288
A Comparative Study of Some Methods of Estimating Robust Variance Covariance Matrix of the Parameters Estimated by (OLS) in Cross-Sectional Data

 

Abstract

The Classical Normal Linear Regression Model Based on Several hypotheses, one of them is Heteroscedasticity as it is known that the wing of least squares method (OLS), under the existence of these two problems make the estimators, lose their desirable properties, in addition the statistical inference becomes unaccepted table. According that we put tow alternative,  the first one is  (Generalized Least Square) Which is denoted by (GLS), and the second alternative is to (Robust covariance matrix estimation) the estimated parameters method(OLS), and that the way (GLS) method neat and certified, if the capabilities (Efficient) and the statistical inference Thread on the basis of an acceptable but this method requires knowledge and knowledge of the nature of the problem and the private model of the problem, whether the Heteroscedasticity otherwise, the method (GLS) become inappropriate. The second alternative is a matrix contrast common variation fortified it does not require prior knowledge of the nature of your problem model, it's also an easy way and by this method has met with popular and interest in more than two decades by researchers, that the estimated of Robust covariance matrix the estimated parameters method(OLS), shall be according to data that is handled type, and we have dealt with in this study, cross-sectional data where the problem of Heteroscedasticity in contrast may be contained therein(Heteroscedasticity- Consistent Covariance matrix Estimation) and symbolized by the (HCCME) and includes many ways, and we have dealt with in our study of these methods  

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Publication Date
Wed May 03 2017
Journal Name
Journal Of Physical Education
تأثير تمرينات علاجية في تحسين مرونة الجذع وانعكاسها على آلام اسفل الظهر لذوي الاعاقة البدنية

Publication Date
Mon Nov 19 2018
Journal Name
Arab Science Heritage Journal
مصطلح مصطلح (i3-gal2) في ضوء نصوص مسمارية غير منشورة من عصر سلالة أور الثالثة

The verbal formula // i3-gal2 //is a commonly form in the written Sumerian economic texts, starting from the early dynastic period (2900-2372 BC), ending with the Ur III dynasty (2112-2004 BC).  This formula has appeared either without infixes, or accompanied by infixes like / in-da-gal2/,  corresponded in Akkadian the formula: ibaššu ,which is  means "to found, to Storage ", As to the formula / da / come to indicate "to found with, to storage with--).

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Publication Date
Sun Feb 23 2025
Journal Name
Sciences Journal Of Physical Education
تأثير تمرينات مركبة ( بدني- مهاري) في تطوير بعض القدرات البدنية والمهارية للاعبات كرة القدم الصالات

ملخص البحث تنوعت اساليب وطرائق التدريب بشكل واسع وكبير وتعددت الاهداف التدريبية تبعا لخصوصية الاداء في النشاط الرياضي الممارس، وكل هذا جعل امام العاملين في الانشطة الرياضية كم كبير من الحلول لمواجهة المشاكل التي تواجههم في اثناء الاعداء للرياضيين، وتعد التمرينات المركبة واحدة من الاساليب التنظيمية للتمرين التي تضم في محتواها تعدد الاداءات خلال التمرين الواحد مما يتيح للاعب تطبيق متطلبات بدنية او مهارية ا

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Publication Date
Sun Apr 01 2012
Journal Name
Journal Of Educational And Psychological Researches
أثر استراتيجية ( فكر – زاوج – شارك ) في تحصيل مادة التاريخ والاحتفاظ بها لطلاب الصف الرابع الأدبي

The current research aims to know on influence strategy (thinking – pairing – sharing) in learning subject of Islamic civilization of Arab and keep it for students 4th class / literary in order to aim of research , the researcher takes measures of experimental method which included selection of experimental designing with partial adjustment in two groups (experimental and controlling) . Experimental group studies according to strategy (thinking – pairing – sharing) , while controlling group studies according to normal way , the researcher choose Zari secondary school for boys in Baghdad intently to run experiment within it. Sample of studying consist of from (64) students , by (32) student in experimental group and (32) students

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Publication Date
Wed Oct 24 2018
Journal Name
Journal Of Planner And Development
الآليات التخطيطية لتوفير خدمات البنى التحتية في قطاع الإسكان (مدينة الكاظمية المقدسة إنموذجاﹰ )- محلة 413،405،407

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Publication Date
Mon Nov 12 2018
Journal Name
Arab Science Heritage Journal
الحجاج الحِـجاج في الشـعر الأنـدلـسي_ عـصر الطوائـف - (حجاجية الورد والنرجس لأبي بكر بن القوطية* أنموذجاً)

Argumentation in the era of Andalusia poetry Denominate on the orbital roses and narcissus to Abu Bakr bin Gothic model research deals with the subject of Argumentation and employment in Andalusia Poetry has been studied in two sections display in the first reasons of self- Argumentation included human relationships

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Publication Date
Wed Jun 01 2011
Journal Name
Political Sciences Journal
أسس بناء الجهاز الاداري الكفء : قراءة في عهد الامام علي بن ابي طالب لمالك الأشتر

أسس بناء الجهاز الاداري الكفء : قراءة في عهد الامام علي بن ابي طالب لمالك الأشتر

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Publication Date
Sun Apr 01 2012
Journal Name
Journal Of Educational And Psychological Researches
أثر أنموذج وودز في تصحيح المفاهيم الجغرافية ذات الفهم الخاطئ لدى طلاب الصف الأول المتوسط

The present study aims at knowing the effect of Woods' model in correcting the geographical missUnderstanding for first stage students. In order to realize the objective of this study, the researcher used an experimental design with partial adjustment which is experimental group with another control group. The research is confined to the first four chapters of the boon of the principles of geography to be studied for the first stage in the academic year (2010/2011) in Iraq. The researcher chooses purposely the chose a staple form the first stage in Hay Al-Jama'a School for boys, in order to apply the experiment. The total number of the sample was (60) students who were distributed randomly as (30)per group. The researcher matched two gro

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Publication Date
Sun Dec 02 2018
Journal Name
Arab Science Heritage Journal
المواقع الجغرافية التابعة لمدينة دمشق في كتاب تاريخ دمشق الكبير لابن عساكر ت 571هـ/1272م

the history of Damascus by Ibn ' asaakir d. 571 a.h. 1272 m from local histories books concerned with male citizen narrators, to distinguish between rate and Rob them, this book is more a history of Islamic heritage books on Islamic City, and if we know that Ibn ' asaakir translated it for personal

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Publication Date
Thu Oct 25 2018
Journal Name
Journal Of Planner And Development
نظام الفعالية السكنية ومستوى الضوضاء الحالة الدراسية:- منطقة سكنية في مدينة اربيل/ منطقة راستي الجديدة

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