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مقارنة بين اختبار (Gold feld Quandt) الحصين مع اختبارات اخرى للكشف عن عدم تجانس التباين بوجود القيم الشاذة == A Comparison of The Test (Gold Feld Quandt) Modified With Other Tests To Detection The Presence of Heterogeneity of Variance of Outliers Values
Author name:
ايلاف بهاء علوان
Supervisor name:
محمود مهدي حسن البياتي
General topic:
Administration and Economics
Specific topic:
Statistics
Degree:
Master
University:
University of Baghdad - Faculty Of Administration And Economics - Department Of Statistics
Language:
Arabic
University location:
Baghdad
First pages:
07T3457 - p.pdf
Abstract:
ان مشكلة عدم تجانس التباينات في حالة وجود القيم الشاذة لها جانبان الاول : هو كيفية تعامل الاختبارات مع مشكلة عدم تجانس التباينات في حالة وجود القيم الشاذة بالنسبة لانموذج الانحدار الخطي المتعدد حيث نلاحظ ان الاختبارات الاعتيادية (الكلاسيكية ) تعاني من مشا | The problem heterogeneity in the case of the presence of outlier values has two important sides. The first is how to handle the test, which have the problem of lack of heterogeneity in the case of outlier values for the multivariate linear regression model where we notice that the usual tests (the classical) have the problems in the results, and the results obtained will be inaccurate and misleading. Therefore, these will be unreliable results, so it is necessary to use other tests to substitute the regular tests, they will work in the same way of normal teste in the absence of the problem of heterogeneity and they are called robust tests. These tests are Modified GoldfieldQuant, Modified Bayes, and Modified levene. Different percentages of data were cut which are (10% , 25% , 40%) assuming normal distribution of data. A comparison was made of the mentioned tests by using soft ware power of the test of Monte Carlo Simalation then detect the best test by force standard where Bayes robust was the best test for detecting the problem of heterogeneity in the presence of outlier valuesand gave reliable results. In the second side, Box plot was used for the detection of outlier values in real data. As for the practical side, data from the agriculture and cultivation of planning and follow - up / meteorological center were collected and used in this study on the four variables for the year 2013 - 2014 and the variables are : Raining rate (y).Air pressure (x_1).Temperature rate (x_2).Humidity rate (x_3).
