Preferred Language
Articles
/
mRfEXJIBVTCNdQwCQ61g
A N-Radon Based OFDM Trasceivers Design and Performance Simulation Over Different Channel Models
...Show More Authors

In this paper a new method is proposed to perform the N-Radon orthogonal frequency division multiplexing (OFDM), which are equivalent to 4-quadrature amplitude modulation (QAM), 16-QAM, 64-QAM, 256-QAM, ... etc. in spectral efficiency. This non conventional method is proposed in order to reduce the constellation energy and increase spectral efficiency. The proposed method gives a significant improvement in Bit Error Rate performance, and keeps bandwidth efficiency and spectrum shape as good as conventional Fast Fourier Transform based OFDM. The new structure was tested and compared with conventional OFDM for Additive White Gaussian Noise, flat, and multi-path selective fading channels. Simulation tests were generated for different channels parameters values including multi-path gains vector, multi-path delay time vector, and maximum Doppler shift. © 2009 Springer Science+Business Media, LLC.

Scopus Clarivate Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
Design and Simulation of Optical Element Use in Solid State Blue Laser Source
...Show More Authors

Solid state blue laser source is a solid state laser include generation of IR laser light 1064 nm and companied with other wavelength 810 nm that invented from other active medium (Tm:ZBLAN) and non-linear crystal (CLBO) are used to generate fourth harmonic of the resultant wavelength 1874 nm that is blue laser light of 460nm. Several optical component have been designed by multilayer dielectric structure and anti reflection coating analysis. By using MATLAB soft ware, the simulation done and used the following non linear material (ZrO2, HfO2, MgO, SiO, Ta2O5 CaF2) and other linear material (ZnO, MgF2, GaAs, AlAs, BaF2, LiF, TiO2) as coating material. The result showed that as more quarter wave layers are added to the structure, the refl

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
WiMax Network Design and Simulation for Middle Technical University Campus Using OPNET Modeler
...Show More Authors

     This study aims to build a wireless computer network for a large company or university to enhance mobility and allow university users to stay connected at any time or place, which is achieved by applying the Universal Interoperability for Microwave Access (WiMax) technology. WiMax is based on the 802.16 sets of standards and has the most efficient and advanced hardware capabilities to meet the demands of teachers and students to browse the web or download files quickly. OPNET Modeler version 14.5 was used to determine the quality of service parameters of WiMax.

View Publication Preview PDF
Scopus Crossref
Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Design and Simulation of L1-Adaptive Controller for Position Control of DC Servomotor
...Show More Authors

This paper presents L1-adaptive controller for controlling uncertain parameters and time-varying unknown parameters to control the position of a DC servomotor. For the purpose of comparison, the effectiveness of L1-adaptive controller for position control of studied servomotor has been examined and compared with another adaptive controller; Model Reference Adaptive Controller (MRAC). Robustness of both L1-adaptive controller and model reference adaptive controller to different input reference signals and different structures of uncertainty were studied. Three different types of input signals are taken into account; ramp, step and sinusoidal. The L1-adaptive controller ensured uniformly bounded

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 06 2001
Journal Name
المجلة العراقية للعلوم الاحصائية
Suggest formulas for estimating carry-over effects in two-period changeover design
...Show More Authors

This 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).

Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Aip Conference Proceedings
Radon concentrations assessment in tap water for different areas in Baghdad city using Rad7
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Thu Jan 14 2021
Journal Name
Iraqi Journal Of Science
Identifying Digital Forensic Frameworks Based on Processes Models
...Show More Authors

Digital forensic is part of forensic science that implicitly covers crime related to computer and other digital devices. It‟s being for a while that academic studies are interested in digital forensics. The researchers aim to find out a discipline based on scientific structures that defines a model reflecting their observations. This paper suggests a model to improve the whole investigation process and obtaining an accurate and complete evidence and adopts securing the digital evidence by cryptography algorithms presenting a reliable evidence in a court of law. This paper presents the main and basic concepts of the frameworks and models used in digital forensics investigation.

View Publication Preview PDF
Scopus (5)
Crossref (3)
Scopus Crossref
Publication Date
Wed May 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Comparison Between The Performance of Parametric Active Contour Models
...Show More Authors

Snakes, or active contours, are used extensively in computer vision and image processing applications, particularly to locate object boundaries.  In this research, for the segmentation of anatomical structures in medical images three approaches were implemented and compared like (original snake model, distance potential force model and Gradient Vector Flow (GVF) snake model). We used Computed Tomography image (CT) for our experiments.  Our experiments show that original snake model has two problems; first is the limited capture range and the second is the poor convergence. Distance potential force model solved only the first problem of original snake and failed with second problem. Gradient Vector Flow (GVF snake) provides a go

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 01 2012
Journal Name
Journal Of Engineering
DESIGN OF A VARIABLE GAIN NONLINEAR FUZZY CONTROLLER AND PERFORMANCE ENHANCEMENT DUE TO GAIN VARIATION
...Show More Authors

In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.

Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
DESIGN OF A VARIABLE GAIN NONLINEAR FUZZY CONTROLLER AND PERFORMANCE ENHANCEMENT DUE TO GAIN VARIATION
...Show More Authors

In this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.

View Publication Preview PDF
Crossref
Publication Date
Thu May 14 2020
Journal Name
Journal Of Planner And Development
“The role of parametric approach in design highest climatic performance buildings: local housing design patterns as a sample”
...Show More Authors

In light of increasing demand for energy consumption due to life complexity and its requirements, which reflected on architecture in type and size, Environmental challenges have emerged in the need to reduce emissions and power consumption within the construction sector. Which urged designers to improve the environmental performance of buildings by adopting new design approaches, Invest digital technology to facilitate design decision-making, in short time, effort and cost. Which doesn’t stop at the limits of acceptable efficiency, but extends to the level of (the highest performance), which doesn’t provide by traditional approaches that adopted by researchers and local institutions in their studies and architectural practices, limit

... Show More
View Publication Preview PDF