Preferred Language
Articles
/
UhgADJYBVTCNdQwC-YES
A method of multi-dimensional variable selection for additive partial linear models.
...Show More Authors

In high-dimensional semiparametric regression, balancing accuracy and interpretability often requires combining dimension reduction with variable selection. This study intro- duces two novel methods for dimension reduction in additive partial linear models: (i) minimum average variance estimation (MAVE) combined with the adaptive least abso- lute shrinkage and selection operator (MAVE-ALASSO) and (ii) MAVE with smoothly clipped absolute deviation (MAVE-SCAD). These methods leverage the flexibility of MAVE for sufficient dimension reduction while incorporating adaptive penalties to en- sure sparse and interpretable models. The performance of both methods is evaluated through simulations using the mean squared error and variable selection criteria, as- sessing the correct detection of zero coefficients and the false omission of nonzero coef- ficients. A practical application involving financial data from the Baghdad Soft Drinks Company demonstrates their utility in identifying key predictors of stock market value. The results indicate that MAVE-SCAD performs well in high-dimensional and complex scenarios, whereas MAVE-ALASSO is better suited to small samples, producing more parsimonious models. These results highlight the effectiveness of these two methods in addressing key challenges in semiparametric modeling

Scopus Clarivate Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Jan 04 2023
Journal Name
Frontiers In Chemestry
Thermal and flow performance analysis of a concentrated linear Fresnel solar collector with transverse ribs
...Show More Authors

This article deals with the impact of including transverse ribs within the absorber tube of the concentrated linear Fresnel collector (CLFRC) system with a secondary compound parabolic collector (CPC) on thermal and flow performance coefficients. The enhancement rates of heat transfer due to varying governing parameters were compared and analyzed parametrically at Reynolds numbers in the range 5,000–13,000, employing water as the heat transfer fluid. Simulations were performed to solve the governing equations using the finite volume method (FVM) under various boundary conditions. For all Reynolds numbers, the average Nusselt number in the circular tube in the CLFRC system with ribs was found to be larger than that of the plain abs

... Show More
Scopus (6)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The Comparison between the BEKK and DVECH Models of Multivariate GARCH Models with Practical Application
...Show More Authors

The Purpose of this research is a comparison between two types of multivariate GARCH models BEKK and DVECH to forecast using financial time series which are the series of daily Iraqi dinar exchange rate with dollar, the global daily of Oil price with dollar and the global daily of gold price with dollar for the period from 01/01/2014 till 01/01/2016.The estimation, testing and forecasting process has been computed through the program RATS. Three time series have been transferred to the three asset returns to get the Stationarity, some tests were conducted including Ljung- Box, Multivariate Q and Multivariate ARCH to Returns Series and Residuals Series for both models with comparison between the estimation and for

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jan 01 2024
Journal Name
Ieee Access
A Direct Solution Scheme for Wide-Angle Electromagnetic Scattering Problems Using Compressive Sensing-Based Method of Moments
...Show More Authors

View Publication
Scopus Clarivate Crossref
Publication Date
Tue Apr 19 2022
Journal Name
Chemistryselect
A Continuous Flow Injection/Indirect Photometric Method for the Detection of Fosetyl Aluminum in Commercial Pesticide Formulations
...Show More Authors
Abstract<p>Because of their Physico‐chemical characteristics and its composition, the development of new specific analytical methodologies to determine some highly polar pesticides are required. The reported methods demand long analysis time, expensive instruments and prior extraction of pesticide for detection. The current work presents a new flow injection analysis method combined with indirect photometric detection for the determination of Fosetyl‐Aluminum (Fosetyl‐Al) in commercial formulations, with rapid and highly accurate determination involving only construction of manifold system combined with photometric detector without need some of the pre‐treatments to the sample before the analysis such a</p> ... Show More
View Publication
Scopus (6)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sun Sep 01 2019
Journal Name
Baghdad Science Journal
A New Method for the Isolation and Purification of Trigonelline as Hydrochloride from Trigonella foenum-graecum L.
...Show More Authors

Separation of Trigonelline, the major alkaloid in fenugreek seeds, is difficult because the extract of these seeds usually contains Trigonelline, choline, mucilage, and steroidal saponins, in addition to some other substances. This study amis to isolate the quaternary ammonium alkaloid (Trigonelline) and choline from fenugreek seeds (Trigonella-foenum graecum L.) which have similar physiochemical properties by modifying of the classical method. Seeds were defatted and then extracted with methanol. The presence of alkaloids was detected by using Mayer's and Dragendorff's reagents. In this work, trigonilline was isolated with traces of choline by subsequent processes of purification using analytical and preparative TLC techniques.

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of estimation methods for regression model parametersIn the case of the problem of linear multiplicity and abnormal values
...Show More Authors

 A simulation study is used to examine the robustness of some estimators on a multiple linear regression model with problems of multicollinearity and non-normal errors, the Ordinary least Squares (LS) ,Ridge Regression, Ridge Least Absolute Value (RLAV), Weighted Ridge (WRID), MM and a robust ridge regression estimator MM estimator, which denoted as RMM this is the modification of the Ridge regression by incorporating robust MM estimator . finialy, we show that RMM is the best among the other estimators

View Publication Preview PDF
Crossref
Publication Date
Sat Aug 01 2020
Journal Name
Key Engineering Materials
Compressive Strength Performance of Reactive Powder Concrete Using Different Types of Materials as a Partial Replacement of Fine Aggregate
...Show More Authors

Reactive Powder Concrete (RPC) can be incorporate as a one of the most important and progressive concrete technology. It is a special type of ultra-high strength concrete (UHSC) that’s exclude the coarse aggregate from its constitutive materials. In this research an experimental study had been carried out to investigate the effect of using three types of materials (porcelain aggregate) and others sustainable materials (glass waste and granular activated carbon) as a partial replacement of fine aggregate. Four percentages had considered (0, 10, 15 and 20) % to achieve better understanding for the influence of these materials upon the compressive strength of RPC. Four curing ages had included in this study, these are; 7, 28, 60 and

... Show More
View Publication
Crossref (7)
Crossref
Publication Date
Sun Jun 05 2016
Journal Name
Baghdad Science Journal
Partial Purification and Characterization of Catalase from Banana Peels
...Show More Authors

Catalase (EC 1.11.1.6) is a well known enzyme which exists in almost all living creatures exposing to oxygen (such as plants, bacteria, and animals). It is a very necessary enzyme to protect the cell from oxidative detriment by reactive oxygen species (ROS). The aim of this study is the partial purification and characterization of Catalase enzyme from Banana peels. In this study, fresh banana peels are treated with 70 % ethanol ,further separated with chloroform ,water and ethyl acetate respectively .The supernatant of the enzymatic sample which is treated with chloroform is loaded into gel filtration column with Sephadex G-100 (1.0 x 90 cm) equilibrated with pH7 buffer media (phosphate buffer 0.1 M). Kinetic studies of the purified en

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of The College Of Basic Education
A Proposed Steganographic Method in Digital Media
...Show More Authors

WA Shukur, journal of the college of basic education, 2011 The aim of this research is designing and implementing proposed steganographic method. The proposed steganographic method don’t use a specific type of digital media as a cover but it can use all types of digital media such as audio, all types of images, video and all types of files as a cover with the same of security, accuracy and quality of original data, considering that the size of embedded data must be smaller than the size of a cover. The proposed steganographic method hides embedded data at digital media without any changing and affecting the quality of the cover data. This means, the difference rate between cover before hiding operation and stego is zero. The proposed steg

... Show More
View Publication
Publication Date
Mon Aug 21 2023
Journal Name
Sport Tk-revista Euroamericana De Ciencias Del Deporte
Determining the grades and standard levels of some mental skills as an indicator for the selection of young volleyball players
...Show More Authors

ABSTRACT Purpose: The determination of standard scores and levels for some mental skills by researchers is of great importance, especially if it matches the target research sample, Method: as the researchers used the descriptive approach in the survey method, and the researchers chose the sample of youth players for clubs for the season (2022-2021), numbering (127) players, and the researchers identified the scale and procedures and applied it to the research sample, Results: obtained the results that were processed, extracted grades and standard levels, and then interpreted them and obtained conclusions, Conclusion: the most important of which are: The standard levels of mental skills reached the results of the sample studied within the

... Show More
View Publication