Preferred Language
Articles
/
jeasiq-2359
A Comparative Study for Estimate Fractional Parameter of ARFIMA Model
...Show More Authors

      Long memory analysis is one of the most active areas in econometrics and time series where various methods have been introduced to identify and estimate the long memory parameter in partially integrated time series. One of the most common models used to represent time series that have a long memory is the ARFIMA (Auto Regressive Fractional Integration Moving Average Model) which diffs are a fractional number called the fractional parameter. To analyze and determine the ARFIMA model, the fractal parameter must be estimated. There are many methods for fractional parameter estimation. In this research, the estimation methods were divided into indirect methods, where the Hurst parameter is estimated first, and then the fractional integration parameter is estimated from it by a relation between them. As for direct methods, the fractional integration parameter is estimated directly without relying on Hurst's parameter, and most of them are semi parametric methods. In this paper, some of the most common direct methods were used to estimate the fraction modulus namely (Geweke-Porter-Hudak, Smoothed Geweke-Porter-Hudak, Local Whittle, Wavelet and weighted wavelet), using simulation method with different value of (d) and different size of time series. The comparison between the methods was done using the mean squared error (MSE). It turns out that the best methods to estimate the fractional parameter is (Local Whittle).

      The ARFIMA model was generated by a function programmed by the MATLAB statistical program

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Sep 30 2026
Journal Name
Iraqi Journal Of Mechanical And Material Engineering
STUDY ON THE PARAMETER OPTIMIZATION INMAGNETIC ABRASIVE POLISHING FORBRASS CUZN33PLATE USING TAGUCHI METHOD
...Show More Authors

This paper describes a new finishing process using magnetic abrasives were newly made to finish effectively brass plate that is very difficult to be polished by the conventional machining processes. Taguchi experimental design method was adopted for evaluating the effect of the process parameters on the improvement of the surface roughness and hardness by the magnetic abrasive polishing. The process parameters are: the applied current to the inductor, the working gap between the workpiece and the inductor, the rotational speed and the volume of powder. The analysis of variance(ANOVA) was analyzed using statistical software to identify the optimal conditions for better surface roughness and hardness. Regressions models based on statistical m

... Show More
View Publication
Publication Date
Tue Sep 15 2020
Journal Name
Journal Of Baghdad College Of Dentistry
Salivary mucoepidermoid carcinoma, auclair vs brandwein grading system: A histopathological comparative study
...Show More Authors

Background: The grading systems of salivary mucoepidermoid carcinoma depend on different histologic and morphologic features. The aim of this study was to compare between Auclair and Brandwein systems according to their histologic criteria, and the type of cell predominant. Materials and Methods: Twenty-one case included hematoxylin-eosin (H&E) stained tissue slides that were diagnosed as MEC, originally categorized into low and high grade type regardless of the grading system, have meticulously undergone histopathologic review. The sample was graded according to criteria owing to Auclair and Brandwein methods. The predominant type of cells was determined by microscopic examination according to grade of tumor. Results: Regarding the

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Sat Feb 03 2018
Journal Name
Al- Utroha Journal
Grice’s Maxims in British and American Conversation: A Comparative Study.
...Show More Authors

DBN Rashid, Al- Utroha Journal, 2018

View Publication
Publication Date
Tue Aug 07 2018
Journal Name
Oral And Maxillofacial Surgery
Mandibular war injuries caused by bullets and shell fragments: a comparative study
...Show More Authors

View Publication
Scopus (7)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Tue Aug 07 2018
Journal Name
Oral And Maxillofacial Surgery
Mandibular war injuries caused by bullets and shell fragments: a comparative study
...Show More Authors

View Publication
Scopus (7)
Crossref (11)
Scopus Crossref
Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة بعض طرائق التعويض الأحادي للبيانات المفقودة لدالة الكثافة الاحتمالية للتوزيع الطبيعي ثنائي المتغيرات
...Show More Authors

In 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. 

 

View Publication Preview PDF
Crossref
Publication Date
Sat Dec 17 2022
Journal Name
Applied Sciences
A Hybrid Artificial Intelligence Model for Detecting Keratoconus
...Show More Authors

Machine learning models have recently provided great promise in diagnosis of several ophthalmic disorders, including keratoconus (KCN). Keratoconus, a noninflammatory ectatic corneal disorder characterized by progressive cornea thinning, is challenging to detect as signs may be subtle. Several machine learning models have been proposed to detect KCN, however most of the models are supervised and thus require large well-annotated data. This paper proposes a new unsupervised model to detect KCN, based on adapted flower pollination algorithm (FPA) and the k-means algorithm. We will evaluate the proposed models using corneal data collected from 5430 eyes at different stages of KCN severity (1520 healthy, 331 KCN1, 1319 KCN2, 1699 KCN3 a

... Show More
View Publication
Scopus (4)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Mon Oct 07 2019
Journal Name
Construction Innovation
A hybrid conceptual model for BIM in FM
...Show More Authors
Purpose

The purpose of this paper is to develop a hybrid conceptual model for building information modelling (BIM) adoption in facilities management (FM) through the integration of the technology task fit (TTF) and the unified theory of acceptance and use of technology (UTAUT) theories. The study also aims to identify the influence factors of BIM adoption and usage in FM and identify gaps in the existing literature and to provide a holistic picture of recent research in technology acceptance and adoption in the construction industry and FM sector.

Design/methodology/approach
... Show More
View Publication
Scopus (37)
Crossref (31)
Scopus Clarivate Crossref
Publication Date
Tue Jun 20 2023
Journal Name
Bulletin Of The Iraq Natural History Museum
A COMPARATIVE-MORPHOLOGICAL STUDY OF SKULLS IN TWO SPECIES OF CARNIVOROUS AND HERBIVOROUS MAMMALS
...Show More Authors

The skull is one of the largest bones in the body. It is classified into flat bones that maintain the important organic structures; which are the brain, eyes, and tongue. The skull is a strong support for preserving these organs but they are various according to the type of animals and the environments in which they live and the nature of their nutrition. There are many differences among living organisms in terms of the bones in the skull, their difference or disappearance and their length in the shape of the head. The samples were taken from the scientific storage in the Iraq Natural History Research Center and Museum; Cape hare Lepus capensis (Linnaeus, 1758) and Red fox Vulpes vulpes (Linnaeus, 1758) and the study was conducted o

... Show More
View Publication
Scopus Crossref
Publication Date
Sun Feb 18 2024
Journal Name
Fitness, Performance And Health Journal
A Comparative Study of Some Types of Muscular Strength Among Middle-Distance Runner Athletes
...Show More Authors

The research aims to conduct a comparative study between the events (800) m and (1500) m track in the types of muscular strength and to identify the differences between them among Iraqi sports club players. The sample represented the players participating in the Iraqi Athletics Championship for the period between (02/11/2023) and (04 /11/2023), and their number was (16) players (8) for each event, as the selection was made intentionally.  The researchers used the descriptive approach to achieve the goal of the research and used the statistical package (SPSS) to process the data statistically. According to the results collected, it was found that there was superiority among the intermediate track players (800) m in explosive power and the s

... Show More
View Publication Preview PDF