Preferred Language
Articles
/
OBdc4I4BVTCNdQwCYFl_
Absorption Coefficient of a Double-Layer Inhomogeneous Micro-perforated Panel Backed with Multiple Cavity Depths
...Show More Authors

Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared with the conventional double- and even triple-layer MPPs. The bandwidth can be increased to higher frequency by decreasing the cavity depth behind a sub-MPP with small hole diameter and a high perforation ratio, and to lower frequency by increasing the cavity depth behind a sub-MPP with large hole diameter and a small perforation ratio. The experimental data, measured by impedance tube, are in good agreement with the predicted results.

Scopus Clarivate Crossref
View Publication
Publication Date
Sun Nov 19 2023
Journal Name
Aip Conference Proceedings
Designing a database for a three dimensional model using geomatics techniques
...Show More Authors

View Publication Preview PDF
Scopus Crossref
Publication Date
Fri Nov 24 2017
Journal Name
Journal Of Engineering
A new analytic method to tune a fractional order PID controller
...Show More Authors

This paper proposes a new method to tune a fractional order PID controller. This method utilizes both the analytic and numeric approach to determine the controller parameters. The control design specifications that must be achieved by the control system are gain crossover frequency, phase margin, and peak magnitude at the resonant frequency, where the latter is a new design specification suggested by this paper. These specifications results in three equations in five unknown variables. Assuming that certain relations exist between two variables and discretizing one of them, a performance index can be evaluated and the optimal controller parameters that minimize this performance index are selected. As a case study, a third order linear time

... Show More
Publication Date
Tue Jan 01 2019
Journal Name
International Journal Of Information Systems And Change Management
Designing a knowledge management measurement for educational institutions: a qualitative research
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Fri Nov 24 2017
Journal Name
Journal Of Engineering
A New Analytic Method to Tune a Fractional Order PID Controller
...Show More Authors

This paper proposes a new method to tune a fractional order PID controller. This method utilizes both the analytic and numeric approach to determine the controller parameters. The control design specifications that must be achieved by the control system are gain crossover frequency, phase margin, and peak magnitude at the resonant frequency, where the latter is a new design specification suggested by this paper. These specifications results in three equations in five unknown variables. Assuming that certain relations exist between two variables and discretizing one of them, a performance index can be evaluated and the optimal controller parameters that minimize this performance index are selected. As a case study, a thir

... Show More
View Publication Preview PDF
Publication Date
Sat Feb 09 2019
Journal Name
Journal Of The College Of Education For Women
Hybrid Transform Based Denoising with Block Thresholding
...Show More Authors

A frequently used approach for denoising is the shrinkage of coefficients of the noisy signal representation in a transform domain. This paper proposes an algorithm based on hybrid transform (stationary wavelet transform proceeding by slantlet transform); The slantlet transform is applied to the approximation subband of the stationary wavelet transform. BlockShrink thresholding technique is applied to the hybrid transform coefficients. This technique can decide the optimal block size and thresholding for every wavelet subband by risk estimate (SURE). The proposed algorithm was executed by using MATLAB R2010aminimizing Stein’s unbiased with natural images contaminated by white Gaussian noise. Numerical results show that our algorithm co

... Show More
View Publication Preview PDF
Publication Date
Fri Jan 01 2010
Journal Name
Iraqi Journal Of Science
RETRIEVING DOCUMENT WITH COMPACT GENETIC ALGORITHM(CGA)
...Show More Authors

Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
International Journal Of Agricultural And Statistical Sciences
ON ERROR DISTRIBUTION WITH SINGLE INDEX MODEL
...Show More Authors

In this paper, the error distribution function is estimated for the single index model by the empirical distribution function and the kernel distribution function. Refined minimum average variance estimation (RMAVE) method is used for estimating single index model. We use simulation experiments to compare the two estimation methods for error distribution function with different sample sizes, the results show that the kernel distribution function is better than the empirical distribution function.

Scopus
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Hyperprolactenemia in Women with Systemic Lupus Erythematusus
...Show More Authors

Recent accumulated evidences suggest that prolactin is an important immunomodulator and may have a role in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to assess the frequency of hyperprolactinemia in women with SLE and to evaluate its correlation with disease flares. Serum prolactin levels were measured in 62 women with SLE and 50 age- and sex-matched healthy controls. In patients and control groups prolactin levels were determined by immunoradiometric assay (IRMA). The prolactin level was found to be higher than normal rang in (40.3%) of SLE patients in active stage versus only (8.06%) of the same SLE patients but in the inactive stage and in (4%) of control group, the elevation was ranging between mi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Nov 16 2021
Journal Name
Journal Of Clinical Laboratory Analysis
Hematological changes associated with COVID‐19 infection
...Show More Authors
Abstract<sec><title>Background

The unresolved COVID‐19 pandemic considerably impacts the health services in Iraq and worldwide. Consecutive waves of mutated virus increased virus spread and further constrained health systems. Although molecular identification of the virus by polymerase chain reaction is the only recommended method in diagnosing COVID‐19 infection, radiological, biochemical, and hematological studies are substantially important in risk stratification, patient follow‐up, and outcome prediction.

Aim

This narrative review summarized the hematological changes including the blood indices, coagulative indicator

... Show More
View Publication
Scopus (45)
Crossref (44)
Scopus Clarivate Crossref
Publication Date
Fri Apr 25 2014
Journal Name
Journal Of Kufa For Nursing Science
Environmental Effects On Women's With Spontaneous Abortion
...Show More Authors

Background: spontaneous abortion constitutes one of the most important adverse pregnancy outcomes affecting human reproduction, and its risk factors are not only affected by biological, demographic factors such as age, gravidity, and previous history of miscarriage,but also by individual women’s personal social characteristics, and by the larger social environment. Objective:To identifyEnvironmental effects on Women's with Spontaneous Abortion. Methodology:Non-probability(purposive sample)of(200) women, who were suffering from spontaneous abortion in maternity unitfrom four hospitals at Baghdad City which include Al-ElwiaMaternity Teaching Hospital, and Baghdad Teaching Hospital at Al-Russafa sector. Al–karckhMaternityHospita

... Show More
View Publication Preview PDF
Crossref