Generally, statistical methods are used in various fields of science, especially in the research field, in which Statistical analysis is carried out by adopting several techniques, according to the nature of the study and its objectives. One of these techniques is building statistical models, which is done through regression models. This technique is considered one of the most important statistical methods for studying the relationship between a dependent variable, also called (the response variable) and the other variables, called covariate variables. This research describes the estimation of the partial linear regression model, as well as the estimation of the “missing at random” values (MAR). Regarding the

The 3-parameter Weibull distribution is used as a model for failure since this distribution is proper when the failure rate somewhat high in starting operation and these rates will be decreased with increasing time .

In practical side a comparison was made between (Shrinkage and Maximum likelihood) Estimators for parameter and reliability function using simulation , we conclude that the Shrinkage estimators for parameters are better than maximum likelihood estimators but the maximum likelihood estimator for reliability function is the better using statistical measures (MAPE)and (MSE) and for different sample sizes.

Note:- n_s : small sample ; n_m=median sample

The aim of present study is to determine the optimum parameters of friction stir welding process and known the most important parameter along with percentage contribution of each parameter which effect on tensile strength and joint efficiency of FS welded joint of  dissimilar aluminum alloys AA2024-T3 and AA7075-T73 of 3 mm thick plates by applied specific number of experiments using Taguchi method .AA2024 was placed on the advancing side and AA7075 on the retreating side. FSW was achieved under three different rotation speeds (898, 1200 and 1710) rpm, three different welding speeds (20, 45 and 69) mm\min , three different pin profiles (cylindrical, threaded cylindrical and cone) and tool tilt angle 2^◦. Taguchi method w

     In the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at

رمي البحث الحالي الى تعّرق أثر أنموذج فراير في اکتساب المفاهيم البلاغية عند طالبات الصف الخامس الادبي في مادة البلاغة. ووضع الباحثون الفرضية الصفرية الآتية: "ليس هناک فرق ذو دلالة احصائية عند مستوى (0.05) بين متوسط ودرجات طالبات المجموعة التجريبية اللواتي يدرسن مادة البلاغة بانموذج فراير، ومتوسط درجات طالبات المجموعة الضابطة اللواتي يدرسن المادة نفسها بالطريقة التقليدية (القياسية) في الاختيار البعدي لا کتسا

The study aimed at ideutifying the impact of scieutific skills in strategy and liabits of mind amony stueuts in tenth grade . The study demanded to choose a sampie that coutaiun (42) student of the fourth grade of the secondary school who were dirided into tow groups , the first is experimental studied according to scieutific skill strategy , and the other controlling , studied according to the  usualway . An achievement test  has been taken that adopted  staudard for mind skills as research tools that are applid after ascertaining  sincerity proved at the end of the experiment .The study has reached to the conclusion that there are statistically significant differnces in farour of the experiment group in both

تهدف الدراسة الحالية إلى معرفة أثر استخدام نموذج ويتلي في اكتساب طلاب الصف الثاني الأساسي لمادة قواعد اللغة العربية. وللتحقق من هدف الدراسة فرضت الفرضيات الصفرية الآتية: الفرضية الصفرية الأولى هي (لا توجد فروق ذات دلالة إحصائية عند مستوى (0.05) بين متوسط ​​درجات المجموعة التجريبية التي درست مادة قواعد اللغة العربية وفق نموذج ويتلي ومتوسط ​​درجات المجموعة الضابطة التي درست مادة قواعد اللغة العربية وفق الطريق