The purpose behind building the linear regression model is to describe the real linear relation between any explanatory variable in the model and the dependent one, on the basis of the fact that the dependent variable is a linear function of the explanatory variables and one can use it for prediction and control. This purpose does not cometrue without getting significant, stable and reasonable estimatros for the parameters of the model, specifically regression-coefficients. The researcher found that "RUF" the criterian that he had suggested accurate and sufficient to accomplish that purpose when multicollinearity exists provided that the adequate model that satisfies the standard assumpitions of the error-term can be assigned. It is wrong to ignore the assumptions and depend directly on the least "MSE & PRESS" and greatest " " because it satisfies the model with false fit to data, whereas the regession coefficients are still unstable and unreasonable because of the multicollinearity and the effect of the error-term on the explanatory and predicted power. So the researcher has made procedures for using his criterion "RUF" to get the real best subset linear model.
This paper proposes and studies an ecotoxicant system with Lotka-Volterra functional response for predation including prey protective region. The equilibrium points and the stability of this model have been investigated analytically both locally and globally. Finally, numerical simulations and graphical representations have been utilized to support our analytical findings
Sewer systems are used to convey sewage and/or storm water to sewage treatment plants for disposal by a network of buried sewer pipes, gutters, manholes and pits. Unfortunately, the sewer pipe deteriorates with time leading to the collapsing of the pipe with traffic disruption or clogging of the pipe causing flooding and environmental pollution. Thus, the management and maintenance of the buried pipes are important tasks that require information about the changes of the current and future sewer pipes conditions. In this research, the study was carried on in Baghdad, Iraq and two deteriorations model's multinomial logistic regression and neural network deterioration model NNDM are used to predict sewers future conditions. The results of the
... Show MoreIn this paper, we will study non parametric model when the response variable have missing data (non response) in observations it under missing mechanisms MCAR, then we suggest Kernel-Based Non-Parametric Single-Imputation instead of missing value and compare it with Nearest Neighbor Imputation by using the simulation about some difference models and with difference cases as the sample size, variance and rate of missing data.
Net pay is one of the most important parameters used in determining initial oil in place of a reservoir. It can be delineated through the using of limiting values of the petrophysical properties of the reservoir. Those limiting values are named as the cutoff. This paper provides an insight into the application of regression line method in estimating porosity, clay volume and water saturation cutoff values in Mishrif reservoir/ Missan oil fields. The study included 29 wells distributed in seven oilfields of Halfaya, Buzurgan, Dujaila, Noor, Fauqi, Amara and Kumait.
This study is carried out by applying two types of linear regressions: Least square and Reduce Major Axis Regression.
The Mishrif formation was
... Show MoreResearchers often equate database accounting models in general and the Resources-Events-Agents (REA) accounting model in particular with events accounting as proposed by Sorter (1969). In fact, REA accounting, database accounting, and events accounting are very different. Because REA accounting has become a popular topic in AIS research, it is important to agree on exactly what is meant by certain ideas, both in concept and in historical origin. This article clarifies the analyzing framework of REA accounting model and highlights the differences between the terms events accounting, database accounting, semantically-modeled accounting, and REA accounting. It als
... Show Moreمن الضروري اجراء تحليل الحساسية للمشاريع الاستثمارية التي يتبناها القطاع العام أو الخاص وذلك لسببين ، الاول هو تضمين عامل المخاطرة واللاتاكد عند تقييم المشروع من الناحية الاقتصادية ، حيث لابد من يكون نسبة مخاطرة وعدم تاكد عند تقييم أي مشروع لمجابهة احداث المستقبل الغير متوقعة ، الثاني المنافسة الشديدة بين المنتجات المحلية والمستوردة ، حيث ان تحليل الحساسية يعطينا صورة عن مدى حساسية القيمة الحالية
... Show MoreModeling data acquisition systems (DASs) can support the vehicle industry in the development and design of sophisticated driver assistance systems. Modeling DASs on the basis of multiple criteria is considered as a multicriteria decision-making (MCDM) problem. Although literature reviews have provided models for DASs, the issue of imprecise, unclear, and ambiguous information remains unresolved. Compared with existing MCDM methods, the robustness of the fuzzy decision by opinion score method II (FDOSM II) and fuzzy weighted with zero inconsistency II (FWZIC II) is demonstrated for modeling the DASs. However, these methods are implemented in an intuitionistic fuzzy set environment that restricts the ability of experts to provide mem
... Show Moreأن التقدم والتطور العلمي اللذين حدثا خلال القرن العشرين كان لهما اثر كبير في المسيرة العلمية ، حيث أن من المفترض على أفراد مجتمع المتعلمين أن يتزودوا بمهارات التفكير العلمي لكي تمكنهم من العيش في العصر الحالي وليشاركوا فيه بذكاء وفاعلية حتى يحققوا لذاتهم ملائمة أفضل مع التغييرات والتطورات المختلفة التي حدثت في العالم لذا فان طرائق التدريس أصبحت حاجة ملحة لا تقل أهميتها عن المدرس والمادة الدراسية حيث أ
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