Preferred Language
Articles
/
alkej-132
Channel Estimation and Prediction Based Adaptive Wireless Communication Systems
...Show More Authors

Wireless channels are typically much more noisy than wired links and subjected to fading due to multipath  propagation which result in ISI and hence high error rate. Adaptive modulation is a powerful technique to improve the tradeoff between spectral efficiency and Bit Error Rate (BER). In order to adjust the transmission rate, channel state information (CSI) is required at the transmitter side.

In this paper the performance enhancement of using linear prediction along with channel estimation to track the channel variations and adaptive modulation were examined. The simulation results shows that the channel estimation is sufficient for low Doppler frequency shifts (<30 Hz), while channel prediction is much more suited at high Doppler shifts with same SNR and target BER=10-4. It was shown that the performance at higher Doppler frequency shifts (<30Hz) was improved by more than 2dB over channel estimation at target BER=10-4 and 32QAM constellation used.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Mar 10 2017
Journal Name
Superconductor Science And Technology
Conceptual designs of conduction cooled MgB<sub>2</sub> magnets for 1.5 and 3.0 T full body MRI systems
...Show More Authors

View Publication
Scopus (64)
Crossref (61)
Scopus Clarivate Crossref
Publication Date
Tue Aug 14 2018
Journal Name
International Journal Of Engineering &amp; Technology
Hybrid DWT-DCT compression algorithm &amp; a new flipping block with an adaptive RLE method for high medical image compression ratio
...Show More Authors

Huge number of medical images are generated and needs for more storage capacity and bandwidth for transferring over the networks. Hybrid DWT-DCT compression algorithm is applied to compress the medical images by exploiting the features of both techniques. Discrete Wavelet Transform (DWT) coding is applied to image YCbCr color model which decompose image bands into four subbands (LL, HL, LH and HH). The LL subband is transformed into low and high frequency components using Discrete Cosine Transform (DCT) to be quantize by scalar quantization that was applied on all image bands, the quantization parameters where reduced by half for the luminance band while it is the same for the chrominance bands to preserve the image quality, the zig

... Show More
View Publication
Crossref
Publication Date
Thu Feb 16 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Isolation and Structural Characterization of Quercetin 3-O-Rhamnoside and Essential oil Estimation from Leaves of Iraqi Cupressus sempervirens L (Conference Paper )#
...Show More Authors

     Cupressus sempervirens L., Cupressaceae, that is known as evergreen cypress, Mediterranean cypress and in Arabic called “al -Sarw. It is an evergreen, medium sized, longevity, and wide distributed over all the world. The plant represents an important member of conifer plants which characterized with aromatic leaves and cones. Cupressus sempervirens have been ethnobotanical uses as an antiseptic, relief of cough, astringent, antispasmodic, wound healing and anti-inflammatory. Aims of this work are phytochemical analysis, isolation and structural identification of Quercitroside (quercitrin) and essential oil in Iraqi C. sempervirens. Isolation of quercitrin was

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (1)
Scopus Crossref
Publication Date
Sun May 26 2019
Journal Name
Iraqi Journal Of Science
Bayesian Estimation for Two Parameters of Gamma Distribution under Generalized Weighted Loss Function
...Show More Authors

This paper deals with, Bayesian estimation of the parameters of Gamma distribution under Generalized Weighted loss function, based on 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 in terms of the mean squared errors (MSE’s).

Scopus (7)
Crossref (4)
Scopus Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Aip Conference Proceedings
Comparative analysis of parameter estimation methods for Meixner process using wavelet packet transform
...Show More Authors

The current research creates an overall relative analysis concerning the estimation of Meixner process parameters via the wavelet packet transform. Of noteworthy presentation relevance, it compares the moment method and the wavelet packet estimator for the four parameters of the Meixner process. In this paper, the research focuses on finding the best threshold value using the square root log and modified square root log methods with the wavelet packets in the presence of noise to enhance the efficiency and effectiveness of the denoising process for the financial asset market signal. In this regard, a simulation study compares the performance of moment estimation and wavelet packets for different sample sizes. The results show that wavelet p

... Show More
View Publication
Scopus Crossref
Publication Date
Mon May 11 2020
Journal Name
Baghdad Science Journal
Proposing Robust LAD-Atan Penalty of Regression Model Estimation for High Dimensional Data
...Show More Authors

         The issue of penalized regression model has received considerable critical attention to variable selection. It plays an essential role in dealing with high dimensional data. Arctangent denoted by the Atan penalty has been used in both estimation and variable selection as an efficient method recently. However, the Atan penalty is very sensitive to outliers in response to variables or heavy-tailed error distribution. While the least absolute deviation is a good method to get robustness in regression estimation. The specific objective of this research is to propose a robust Atan estimator from combining these two ideas at once. Simulation experiments and real data applications show that the p

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Tue May 01 2018
Journal Name
International Journal Of Medical Research & Health Sciences
Estimation of Serum Matrix Metalloproteinases-1 Levels in Iraqi Female Patients with Osteoarthritis
...Show More Authors

This study was established to investigate the correlation between the expression of matrix metalloproteinases (MMP-1) and the pathogenesis of osteoarthritis (OA). Blood samples were collected from 55 female patients with inflammatory OA and controls for estimation of serum (MMP-1) levels. In the current study, there is significant increase (p<0.001) in the mean of serum MMP-1 levels in osteoarthritis females (4027.73 ± 1345.28 pg/ml) than that in control females (798.76 ± 136.79 pg/ml). It was concluded that MMP-1 may be associated with the pathogenesis of osteoarthritis.

Publication Date
Wed Jan 11 2023
Journal Name
Mathematical Problems In Engineering
Bayesian Methods for Estimation the Parameters of Finite Mixture of Inverse Rayleigh Distribution
...Show More Authors

Methods of estimating statistical distribution have attracted many researchers when it comes to fitting a specific distribution to data. However, when the data belong to more than one component, a popular distribution cannot be fitted to such data. To tackle this issue, mixture models are fitted by choosing the correct number of components that represent the data. This can be obvious in lifetime processes that are involved in a wide range of engineering applications as well as biological systems. In this paper, we introduce an application of estimating a finite mixture of Inverse Rayleigh distribution by the use of the Bayesian framework when considering the model as Markov chain Monte Carlo (MCMC). We employed the Gibbs sampler and

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Clarivate Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Second International Conference On Innovations In Software Architecture And Computational Systems (isacs 2022)
Permeability estimation of Yamama formation in a Southern Iraqi oil field, case study
...Show More Authors

Permeability is one of the essential petrophysical properties of rocks, reflecting the rock's ability to pass fluids. It is considered the basis for building any model to predict well deliverability. Yamama formation carbonate rocks are distinguished by sedimentary cycles that separate formation into reservoir units and insulating layers, a very complex porous system caused by secondary porosity due to substitute and dissolution processes. Those factors create permeability variables and vary significantly. Three ways used for permeability calculation, the firstly was the classical method, which only related the permeability to the porosity, resulting in a weak relationship. Secondly, the flow zone indicator (FZI) was divided reservoir into

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (4)
Scopus Crossref
Publication Date
Mon Apr 01 2024
Journal Name
Iraqi Postgraduate Medical Journal
Estimation of Prevalence rate of Sjogren’s syndrome among Rheumatology clinic patients in Iraq
...Show More Authors

View Publication
Crossref