Preferred Language
Articles
/
alkej-611
Peak to Average Power Ratio Reduction of OFDM Signals Using Clipping and Iterative Processing Methods
...Show More Authors

One of the serious problems in any wireless communication system using multi carrier modulation technique like Orthogonal Frequency Division Multiplexing (OFDM) is its Peak to Average Power Ratio (PAPR).It limits the transmission power due to the limitation of dynamic range of Analog to Digital Converter and Digital to Analog Converter (ADC/DAC) and power amplifiers at the transmitter, which in turn sets the limit over maximum achievable rate.

        This issue is especially important for mobile terminals to sustain longer battery life time. Therefore reducing PAPR can be regarded as an important issue to realize efficient and affordable mobile communication services.

        This paper presents an efficient PAPR reduction method for OFDM signal. This method is based on clipping and iterative processing. Iterative processing is performed to limit PAPR in time domain but the subtraction process of the peak that over PAPR threshold with the original signal is done in frequency domain, not in time like usual clipping technique. The results of this method is capable of reducing the PAPR significantly with minimum bit error rate (BER) degradation.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Probabilistic Model building using the Transformation Entropy for the Burr type –xii Distribution
...Show More Authors

Entropy define as uncertainty measure has been transfared by using the cumulative distribution function and reliability function for the Burr type – xii. In the case of data which suffer from volatility to build a model the probability distribution on every failure of a sample after achieving limitations function, probabilistic distribution. Has been derived formula probability distribution of the new transfer application entropy on the probability distribution of continuous Burr Type-XII and tested a new function and found that it achieved the conditions function probability, been derived mean and function probabilistic aggregate in order to be approved in the generation of data for the purpose of implementation of simulation

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jan 11 2018
Journal Name
Al-khwarizmi Engineering Journal
Control on a 2-D Wing Flutter Using an Adaptive Nonlinear Neural Controller
...Show More Authors

An adaptive nonlinear neural controller to reduce the nonlinear flutter in 2-D wing is proposed in the paper. The nonlinearities in the system come from the quasi steady aerodynamic model and torsional spring in pitch direction. Time domain simulations are used to examine the dynamic aero elastic instabilities of the system (e.g. the onset of flutter and limit cycle oscillation, LCO). The structure of the controller consists of two models :the modified Elman neural network (MENN) and the feed forward multi-layer Perceptron (MLP). The MENN model is trained with off-line and on-line stages to guarantee that the outputs of the model accurately represent the plunge and pitch motion of the wing and this neural model acts as the identifier. Th

... Show More
View Publication Preview PDF
Publication Date
Mon Dec 05 2022
Journal Name
Baghdad Science Journal
Electron lens Optimization for Beam Physics Research using the Integrated Optics Test Accelerator
...Show More Authors

This study proposed control system that has been presented to control the electron lens resistance in order to obtain a stabilized electron lens power. This study will layout the fundamental challenges, hypothetical plan arrangements and development condition for the Integrable Optics Test Accelerator (IOTA) in progress at Fermilab. Thus, an effective automatic gain  control (AGC) unit has been introduced which prevents fluctuations in the internal resistance of the electronic lens caused by environmental influences to affect the system's current and power values ​​and keep them in stable amounts. Utilizing this unit has obtained level balanced out system un impacted with electronic lens surrounding natural varieties.

View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Mon Jan 01 2024
Journal Name
Applied Thermal Engineering
Experimental evaluation of thermal efficiency, electrical efficiency, and power production of low-concentrating photovoltaic-thermal system with micro-jet channel
...Show More Authors

The efficient behavior of a low-concentrating photovoltaic-thermal system with a micro-jet channel (LCPV/T-JET) and booster mirror reflector is experimentally evaluated here. Micro-jets promote the thermal management of PV solar cells by implementing jet water as active cooling, which is still in the early stages of development. The booster mirror reflector concentrates solar irradiance into solar cells and improves the thermal, electrical, and combined efficiencies of the LCPV/T-JET system. The LCPV/T-JET system was tested under ambient weather conditions in the city of Bangi, Selangor, Malaysia, and all data was recorded between 10:00 a.m. and 4:00 p.m. Parametric studies were conducted to compare the performance of the LCPV/T-JET system

... Show More
View Publication
Scopus (31)
Crossref (30)
Scopus Clarivate Crossref
Publication Date
Fri Sep 01 2023
Journal Name
Al-khwarizmi Engineering Journal
Green Fabrication and Characterization of Zinc Oxide Nanoparticles using Eucalyptus Leaves for Removing Acid Black 210 Dye from an Aqueous Medium
...Show More Authors

This study uses an environmentally friendly and low-cost synthesis method to manufacture zinc oxide nanoparticles (ZnO NPs) by using zinc sulfate. Eucalyptus leaf extract is an effective chelating and capping agent for synthesizing ZnO NPs. The structure, morphology, thermal behavior, chemical composition, and optical properties of ZnO nanoparticles were studied utilizing FT-IR, FE-SEM, EDAX, AFM, and Zeta potential analysis. The FE-SEM pictures confirmed that the ZnO NPs with a size range of (22-37) nm were crystalline and spherical. Two methods were used to prepare ZnO NPs. The first method involved calcining the resulting ZnO NPs, while the second method did not. The prepared ZnO NPs were used as adsorbents for removing acid black 210

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (4)
Scopus Crossref
Publication Date
Sun Oct 11 2026
Journal Name
Iraqi Journal Of Applied Physics
Effect of Gas Mixing Ratio on Energy Band Gap of Mixed-Phase Titanium Dioxide Nanostructures Prepared by Reactive Magnetron Sputtering Technique
...Show More Authors

View Publication
Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Determination Of The Efficient Production Plans For Al-Shaheed Public Company By Using Tatget Motad Model Under Risk And Uncertainty
...Show More Authors

The research aims to derive the efficient industrial plans for Al – shaheed public company under risk by using Target MOTAD as a linear alternative  model for the quadratic programming models.

The results showed that there had been a sort of (trade- off) between risk and the expected gross margins. And if the studied company strives to get high gross margin, it should tolerate risk and vice versa. So the management  of Al- Shaheed Company to be invited to apply the suitable procedures in the production process, in order to get efficient plans that improves it's  performance .

View Publication Preview PDF
Crossref
Publication Date
Sun Feb 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Use of model sales man fuzzy multi-objective linear for speed up and rationing in the transport mechanism used in the General Company for grain Processing
...Show More Authors

     Applications of quantitative methods, which had been explicit attention during previous period (the last two centuries) is the method of application sales man or traveling salesman method. According to this interest by the actual need for a lot of the production sectors and companies that distribute their products, whether locally made or the imported for customers or other industry sectors where most of the productive sectors and companies distributed always aspired to (increase profits, imports, the production quantity, quantity of exports. etc. ...) this is the part of the other hand, want to behave during the process of distribution routes that achieve the best or the least or most appropriate.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 15 2011
Journal Name
Iraqi Journal Of Laser
Laser Hole Drilling of Stainless Steel 321H and Steel 33 Using 3D CO2 Laser CNC Machine
...Show More Authors

In present work an investigation for precise hole drilling via continuous wave (CW) CO2 laser at 150 W maximum output power and wavelength 10.6 μm was achieved with the assistance of computerized numerical controlled (CNC) machine and assist gases. The drilling process was done for thin sheets (0.1 – 0.3 mm) of two types of metals; stainless steel (sst) 321H, steel 33 (st). Changing light and process parameters such as laser power, exposure time and gas pressure was important for getting the optimum results. The obtained results were supported with computational results using the COMSOL 3.5a software code.

View Publication Preview PDF
Publication Date
Sun Jan 01 2017
Ultra low power and highly linearized LNA for V-band RF applications in 180 nm CMOS technology
...Show More Authors

Scopus (3)
Crossref (3)
Scopus Clarivate Crossref