Abstract

The multiple linear regression model of the important regression models used in the analysis for different fields of science Such as business, economics, medicine and social sciences high in data has undesirable effects on analysis results . The multicollinearity is a major problem in multiple linear regression. In its simplest state, it leads to the departure of the model parameter that is capable of its scientific properties, Also there is an important problem in regression analysis is the presence of high leverage points in the data have undesirable effects on the results of the analysis , In this research , we present some of

Multiple linear regressions are concerned with studying and analyzing the relationship between the dependent variable and a set of explanatory variables. From this relationship the values of variables are predicted. In this paper the multiple linear regression model and three covariates were studied in the presence of the problem of auto-correlation of errors when the random error distributed the distribution of exponential. Three methods were compared (general least squares, M robust, and Laplace robust method). We have employed the simulation studies and calculated the statistical standard mean squares error with sample sizes (15, 30, 60, 100). Further we applied the best method on the real experiment data representing the varieties of

اتجهت دول العالم الى تسخير جميع الإمكانيات والخبرات والعلوم من اجل الوصول الى مستويات متقدمة في الرياضات المختلفة ويهدف التدريب الرياضي إلى إعداد اللاعبين إعدادا جيدا تكمن مشكلة البحث من خلال خبرة الباحثتان الميدانية ومتابعة تدريبات لاعبي المدرسة التخصصية كرة اليد فقد لوحظ هناك ضعف واضح في الأداء المهاري ولابد من تطوير أوجه الضعف لتحقيق مستوى انجاز افضل . ويهدف البحث اعداد تمرينات خاصة بأستخدام جهاز ا

تم إستعراض تقدير معلمتي التوزيع اللوجستي بإستعمال طريقة ذات مقدرات مضبوطة وهي طريقة العزوم، ومقارنتها بمقدرات تقريبية مأخوذة بالأساس من أسلوب طريقة (وايت) في التقدير بأعتبار التوزيع اللوجستي من التوزيعات الأحتمالية الأسية، وهي كل من طريقة المربعات الصغرى الأعتيادية، وطريقة أنحدار الحرف، وأقتراح تطبيق طريقة أنحدار الحرف المعدلة على هذا التوزيع. وتم أستحصال النتائج بالأستناد الى تجارب محاكاة لتلك الطر

    This article aims to explore the importance of estimating the a semiparametric regression function ,where we suggest a new estimator beside the other combined estimators and then we make a comparison among them by using simulation technique . Through the simulation results we find  that the suggest estimator is the best with the first and second models ,wherealse for the third model we find Burman and Chaudhuri (B&C) is best.

The penalized least square method is a popular method to deal with high dimensional data ,where  the number of explanatory variables is large than the sample size . The properties of  penalized least square method are given high prediction accuracy and making estimation and variables selection

 At once. The penalized least square method gives a sparse model ,that meaning a model with small variables so that can be interpreted easily .The penalized least square is not robust ,that means very sensitive to the presence of outlying observation , to deal with this problem, we can used a robust loss function to get the robust penalized least square method ,and get robust penalized estimator and

Natural frequency under initial stresses for simply supported cross-ply composite laminated plates (E glass- fiber) are obtained using Refind theory (RPT). This theory accounts for parabolic distribution of the transverse shear strain through the plate thickness and satisfies the zero traction boundary conditions on the surfaces of the plate without using shear correction factors. The governing equations for Eigen value problem under initial stress are derived using Hamilton’s principle and solved using Navier solution for simply supported cross-ply symmetric and antisymmetric laminated plates. The effect of many design factors such as modulus ratio, thickness ratio and number of laminates on the Natural frequency and buckling stresses

There have been many writings and discussions that dealt with the details and interpretation of the research methods and the identification of the methods and methodological methods used by researchers and writers as they deal with research topics and problems in all fields of natural and human sciences. But we noticed that the movement of science and its knowledge and development requires the identification of suitable tools and methodological methods appropriate for each type of science. In other words, attempts should be established to build appropriate methodological tools for human and cognitive activity that can be referred to as a specific science that sets out certain paths of the human sciences which is certainly the ori

Abstract The study aims to evaluate antifungal activity of petroleum ether extracts from leaves and stems of Rosmarinus officinalis and root of Glycerrhiza glabra , against fungi Fusarium oxysporium , Aspergillus flavus and Penicillium expansum. While the results of sensitivity of the fungi towards petroleum ether extracts showed different activity, petroleum ether extract of Rosmarinus officinalis showed more activity on Aspergillus flavus minimum inhibitory concentration(MIC) was 25 mg /ml and minimum fungicide concentration(MFC) was 37.5 mg /ml, followed by Fusarium oxysporium, (MIC) was 50 mg /ml and (MFC) was 37.5 mg /ml, finally Penicillium expansum (MIC) was 50 mg /ml and (MFC) was 75 mg /ml, used more concentration from petroleum et