The Dirichlet process is an important fundamental object in nonparametric Bayesian modelling, applied to a wide range of problems in machine learning, statistics, and bioinformatics, among other fields. This flexible stochastic process models rich data structures with unknown or evolving number of clusters. It is a valuable tool for encoding the true complexity of real-world data in computer models. Our results show that the Dirichlet process improves, both in distribution density and in signal-to-noise ratio, with larger sample size; achieves slow decay rate to its base distribution; has improved convergence and stability; and thrives with a Gaussian base distribution, which is much better than the Gamma distribution. The performance depen
... Show MoreIn this paper, Bayes estimators for the shape and scale parameters of Gamma distribution under the Entropy loss function have been obtained, assuming Gamma and Exponential priors for the shape and scale parameters respectively. Moment, Maximum likelihood estimators and Lindley’s approximation have been used effectively in Bayesian estimation. Based on Monte Carlo simulation method, those estimators are compared depending on the mean squared errors (MSE’s). The results show that, the performance of the Bayes estimator under Entropy loss function is better than other estimates in all cases.
يعتبر التحكم في تأثير الجودة على أداء المنظمات من الأوراق الرابحة في بيئة الأعمال، اذ تتبنى هذا التوجه عند إعداد خططها المستقبلية، مما يتوجب عليها تجميع جهودها نحو بلوغ هذا الهدف، من أجل تقديم خدمة بالجودة التي تلبي احتياجات الزبائن وتحقق رضاهم. ينظر إلى قضية قياس جودة الانظمة الخدمية من خلال الأبعاد المحددة لذلك، والتي تعتمد أسلوب المساءلة في البعض منها كسلوك الموظفين في هذه المراكز الخدمية، كما تعتمد الأ
... Show Moreفًي التحلٌيل اإلحصائ،ً حٌث تعتبر طرٌمة انحدار شرائح تلعب تمنٌات تحلٌل االنحدار الالمعلمً دوراً مركزٌاً لتمهٌد البٌانات، اذ ٌمكن من خاللها تمدٌر الدوال مباشرة من الجزاء واحدة من أكثر الطرائك المستعملة حالٌاً ( بدالً ة البٌانات الصاخبة)التً تحتوي على أخطاء( أو الملوثة )data noisy من االعتماد على نماذج معلمٌ محددة، وتعتمد طرٌمة التمدٌر المستعملة لمالئمه نموذج انحدار شرائح الجزاء فً الغالب على طرائك المربعات الصغر
... Show Moreان تحليل البقاء هو عبارة عن تحليل البيانات التي تكون في شكل اوقات من اصل الوقت حتى حدوث حدث النهاية ، وفي البحوث الطبية يكون اصل الوقت هو تاريخ تسجيل المفردة او المريض في دراسة ما مثل التجارب السريرية لمقارنة نوعين من الدواء او اكثر اذا كانت نقطة النهاية هي وفاة المريض او اختفاء المفردة فالبيانات الناتجة من هذه العملية تسمى اوقات البقاء اما اذا كانت النهاية هي ليست الوفاة فالبيانات الناتجة تسمى بيانات الوقت ح
... Show MoreThis research aims to suggest formulas to estimate carry-over effects with two-period change-over design, and then, all other effects in the analysis of variance of this design, and find the efficiency of the two-period change-over design relative to another design (say, completely randomized design).
This research aims to solve the problem of selection using clustering algorithm, in this research optimal portfolio is formation using the single index model, and the real data are consisting from the stocks Iraqi Stock Exchange in the period 1/1/2007 to 31/12/2019. because the data series have missing values ,we used the two-stage missing value compensation method, the knowledge gap was inability the portfolio models to reduce The estimation error , inaccuracy of the cut-off rate and the Treynor ratio combine stocks into the portfolio that caused to decline in their performance, all these problems required employing clustering technic to data mining and regrouping it within clusters with similar characteristics to outperform the portfolio
... Show Moreتم 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
... Show MoreThe modern teaching methods, and their importance in achieving the desired learning goals for the individual and the society, have been addressed, as it is necessary to develop the methods, ways and strategies used in the process of teaching the intermediate stages in the various fields in general and the field of physical education in particular, the importance of research is the effect of using the strategy of similarities in teaching some basic skills of basketball for students of the second intermediate. As for the problem of research, the researcher mentioned the lack of use of teachers’ strategy method similarities in the educational units because of its importance, and after study and analysis the researcher found it necessary to i
... Show MoreIn this paper we suggest new method to estimate the missing data in bivariate normal distribution and compare it with Single Imputation method (Unconditional mean and Conditional mean) by using simulation.
استعمال خوارزمية سرب الطيور لحل نماذج صفوف الانتظار مع تطبيق عملي
يعتبر الخزين من الامور الهامة في العديد من الشركات حيث يمثل نسبة 50 % من رأس مال المستثمر الكلي مع شدة الضغط المتمثل الى خفض التكاليف الكلية المتمثلة مع انواع اخرى من حالات عدم التأكد (الضبابية) لذا سوف نقدم في هذا البحث نظام اقتصادي للكميات الكلية ( الانتاج الاقتصادي للكميات) للوصول حجم الدفعة المثلى المضببة (FEOQ) عندما تكون كل المعالم في حالة عدم التأكد حيث يتم تحويلها الى فترة واحدة وبعد ذلك الحصول على حجم الد
... Show MoreGeneralized Additive Model has been considered as a multivariate smoother that appeared recently in Nonparametric Regression Analysis. Thus, this research is devoted to study the mixed situation, i.e. for the phenomena that changes its behaviour from linear (with known functional form) represented in parametric part, to nonlinear (with unknown functional form: here, smoothing spline) represented in nonparametric part of the model. Furthermore, we propose robust semiparametric GAM estimator, which compared with two other existed techniques.
النموذج التجميعي المعمّم GAM من الممهدات متعددة المتغيرات حديثة الأستعمال في تحليل الأنحدار اللامعلمي، ولذا تم تكريس هذا البحث لدراسته ولكن بالصيغة الهجينة،أي عند للظاهرة التي تغير سلوكها من خطي ذات شكل دالي مسبق (معلمي)، ولاخطي بشكل غير معلوم (لامعلمي) والذي سيكون هنا الشريحة التمهيدية. هذا، بالأضافة الى تقديم مقترح لأيجاد مقدّر GAM شبه معلمي حصين ومقارنته بأسلوب تكراري وآخر غير تكراري.
Grey system theory is a multidisciplinary scientific approach, which deals with systems that have partially unknown information (small sample and uncertain information). Grey modeling as an important component of such theory gives successful results with limited amount of data. Grey Models are divided into two types; univariate and multivariate grey models. The univariate grey model with one order derivative equation GM (1,1) is the base stone of the theory, it is considered the time series prediction model but it doesn’t take the relative factors in account. The traditional multivariate grey models GM(1,M) takes those factor in account but it has a complex structure and some defects in " modeling mechanism", "parameter estimation "and "m
... Show MoreIn this research, we use fuzzy nonparametric methods based on some smoothing techniques, were applied to real data on the Iraqi stock market especially the data about Baghdad company for soft drinks for the year (2016) for the period (1/1/2016-31/12/2016) .A sample of (148) observations was obtained in order to construct a model of the relationship between the stock prices (Low, high, modal) and the traded value by comparing the results of the criterion (G.O.F.) for three techniques , we note that the lowest value for this criterion was for the K-Nearest Neighbor at Gaussian function .
في هذا البحث تم استعمال احد الاساليب التقريبية وهو ما يسمى اسلوب المعدل الموزون للنقاط المقربة (Weighted Average of Rounded Points-WARPing) لتقدير انبعاثات ثاني اوكسيد الكاربون CO_2 في العراق عند استعمال مقدريNadaraya-Watson, Local Linear estimator للفترة الممتدة من عام (1990) ولغاية (2019) ومن ثم المقارنة بين اداء تلك المقدرات وقد اثبتت النتائج تفوق طريقة Local Linear estimator وخاصة في النقاط عند نقاط الحد وتميزها عن طريقة Nadaraya–Watson على الرغم من الاداء ا
... Show MoreThis research deals with a shrinking method concerned with the principal components similar to that one which used in the multiple regression “Least Absolute Shrinkage and Selection: LASS”. The goal here is to make an uncorrelated linear combinations from only a subset of explanatory variables that may have a multicollinearity problem instead taking the whole number say, (K) of them. This shrinkage will force some coefficients to equal zero, after making some restriction on them by some "tuning parameter" say, (t) which balances the bias and variance amount from side, and doesn't exceed the acceptable percent explained variance of these components. This had been shown by MSE criterion in the regression case and the percent explained
... Show MoreIn this research, a factorial experiment (4*4) was studied, applied in a completely random block design, with a size of observations, where the design of experiments is used to study the effect of transactions on experimental units and thus obtain data representing experiment observations that The difference in the application of these transactions under different environmental and experimental conditions It causes noise that affects the observation value and thus an increase in the mean square error of the experiment, and to reduce this noise, multiple wavelet reduction was used as a filter for the observations by suggesting an improved threshold that takes into account the different transformation levels based on the logarithm of the b
... Show MoreIn this research, we studied the multiple linear regression models for two variables in the presence of the autocorrelation problem for the error term observations and when the error is distributed with general logistic distribution. The auto regression model is involved in the studying and analyzing of the relationship between the variables, and through this relationship, the forecasting is completed with the variables as values. A simulation technique is used for comparison methods depending on the mean square error criteria in where the estimation methods that were used are (Generalized Least Squares, M Robust, and Laplace), and for different sizes of samples (20, 40, 60, 80, 100, 120). The M robust method is demonstrated the best metho
... Show MoreThe research aims to identify the impact of using the electronic participatory learning strategy according to internet programs in learning some basic basketball skills for middle first graders according to the curricular course, and the sample of research was selected in the deliberate way of students The first stage of intermediate school.As for the problem of research, the researchers said that there is a weakness in the levels of school students in terms of teaching basketball skills, which prompted the researchers to create appropriate solutions by using a participatory learning strategy.The researchers imposed statistically significant differences between pre and post-test tests, in favor of the post tests individually and in favor of
... Show MoreThis research deals with the use of a number of statistical methods, such as the kernel method, watershed, histogram and cubic spline, to improve the contrast of digital images. The results obtained according to the RSME and NCC standards have proven that the spline method is the most accurate in the results compared to other statistical methods
In this article we analysis the data of Iraqi children aged 0-9 months covered in Multiple Indicator Cluster Survey (MICS6-2018) to evaluate the nutritional status . Weight for-age z-score (WAZ), height-for-age z-score (HAZ) and BMI-for-age z-score were compared with the z-scores WHO standards. The overall prevalence of underweight and stunting of the children were 4 % and 11% respectively. Prevalence of overweight based on BMI-for-age for the sexes combined was 21%. Comparing the results obtained from MICS-6 with the results obtained from MICS-4, we find that there is an improvement in the nutritional status of Iraqi children concerning weight, but as for height, we find that there is an increase in the percentage of children who suffer fr
... Show MoreSurvival analysis is widely applied to data that described by the length of time until the occurrence of an event under interest such as death or other important events. The purpose of this paper is to use the dynamic methodology which provides a flexible method, especially in the analysis of discrete survival time, to estimate the effect of covariate variables through time in the survival analysis on dialysis patients with kidney failure until death occurs. Where the estimations process is completely based on the Bayes approach by using two estimation methods: the maximum A Posterior (MAP) involved with Iteratively Weighted Kalman Filter Smoothing (IWKFS) and in combination with the Expectation Maximization (EM) algorithm. While the other
... Show MoreIn this research, one of the nonlinear regression models is studied, which is BoxBOD, which is characterized by nonlinear parameters, as the difficulty of this model lies in estimating its parameters for being nonlinear, as its parameters were estimated by some traditional methods, namely the method of non-linear least squares and the greatest possible method and one of the methods of artificial intelligence, it is a genetic algorithm, as this algorithm was based on two types of functions, one of which is the function of the sum of squares of error and the second is the function of possibility. For comparison between the methods used in the research, the comparison scale was based on the average error squares, and for the purpose of data ge
... Show Moreفي كثير من الأحيان يفشل تحليل المربعات الصغرى (LS) تماماً في حالة وجود قيم شاذة في الظواهر المدروسة، اذ ستفقد OLS خصائصها ومن ثم تفقد صفة المقدر الخطي الجيد Beast Linear Unbiased Estimator (BLUE) لِما تسببه الشواذ Outliers من تأثير سيئ علـى نتـائج التحليـل الاحـصائي للبيانـات اذ أن وجودها يؤدي الى إرباك كبير في تحليل البيانات في حالة إستخدام الطرائق التقليدية، ولعلاج هذه المشكلة تم تطوير أساليب إحصائية جديدة بحيث لا تتأثر بالقي
... Show MoreA new distribution, the Epsilon Skew Gamma (ESΓ ) distribution, which was first introduced by Abdulah [1], is used on a near Gamma data. We first redefine the ESΓ distribution, its properties, and characteristics, and then we estimate its parameters using the maximum likelihood and moment estimators. We finally use these estimators to fit the data with the ESΓ distribution