أن الامم والشعوب لاتستطيع المحافظة على استمرار وجودها وتقدمها ورقيها، إلابفضل إعداد اجيالها المتعاقبة الاعداد السليم المتكامل ، وبقدر ما تحافظ الامم والشعوب على تربية هذه الاجيال للتمسك بدينها ، ومعتقداتها ، واخلاقها ، بقدر ما تحافظ على بقائها وعلو شأنها ، وكما فطنت الامم والشعوب إلى اهمية تربية اجيالها ، فطن اعداؤها الى ضرورة التخريب في جذور البناء الصحيح لتربية الاجيال ( فاطمة ، 1998، ص2).

In linear regression, an outlier is an observation with large residual.  In other words, it is an observation whose dependent-variable value is unusual given its values on the predictor variables. An outlier observation may indicate a data entry error or other problem.

An observation with an extreme value on a predictor variable is a point with high leverage. Leverage is a measure of how far an independent variable deviates from its mean. These leverage points can have an effect on the estimate of regression coefficients.

Robust estimation for regression parameters deals with cases that have very high leverage, and cases that are outliers. Robust estimation is essentially a

      The Costing Accounting is one the analytic tools which plays important role by support the management in planning&  control and decisions-making ,as it became attendant necessity to establish any project whether industrial ,commercial ,service or agriculture ..etc.

     The consolidated accounting system has committed the companies to have their active costing system in which the management can obtain their own data, but we found most of the economic units face problems of applying the costing system because of reasons related to the system design itself or might be related to the requirements of the application success.   

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

ABSTRACT: In dental practice there are many wrong habits that should be recognized and treated. One of them is the irrational antibiotic (AB) administration by patient. This indeed created an important issue in dental clinics first of all drug resistance and super infection. This was analyzed in our study and then the causes were identified and a plan suggested in recommendation hope that it will minimize the outcomes. Results: all those patients were finally subjected to be clinically diagnosed and treated this lead to only one fact, these antibiotics are not effective in one way or another since they are not prescribed by dentist

Roller compacted concrete (RCC) is a material with no slumps and is made from the same raw materials as conventional concrete. The roller compacted dam method, the high paste technique, the corps of engineers method, and the maximum density method are all ways of designing RCC. The evolution of RCC has resulted in a substantial change in construction projects, most notably in dams, because of the sluggish pace of conventional placement, consolidation, and compacting. The construction process was accelerated by incorporating RCC into dams, resulting in a shorter construction period. Research shows that the dams that used RCC had completed one to two years sooner than the dams that used regular concrete (Bagheri an

The main target of this paper is to determine the optimum time for preventive maintenance on machines. Tow methods has been implemented estimating the optimum time duration for preventive maintenance . the first techniques use scheduling depending on data concerning the machine maintenance cost and halted cost from the production reach to the optimum time for maintenance which reflect the minimum cost. Where as the second techniques depends on reability function to estimate the optimum duration time which reflect the minimum cost. The tow techniques above by which we count on in fixing the preventive maintenance both give same result . we also prove that the scheduling method best than the reability function .