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Modulation of Chaos with Optoelectronic Feedback in Semiconductor Laser
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The modulation of chaotic behavior in semiconductor laser with A.C coupling optoelectronic feedback has been numerically and experimentally reported. The experimental and numerical studying for the evaluation of chaos modulation behavior are considered in two conditions, the first condition, when the frequency of the external perturbation is varied, secondly, when the amplitude of this perturbation is changed. This dynamics of the laser output are analyzed by time series, FFT and bifurcation diagram.

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Publication Date
Sun May 14 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A New Design of Fractal Optical Modulation
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In this paper it was designed a new fractal optical modulation by using a new iteration of fractal function, the result was analyzed by MTF evaluation, and it compared with results of normal optical modulation.

The normal and fractal optical modulator is a circular disc which has a radius R=9cm, both of them consist of twenty sectors, ten sectors are opaque and the other ten sectors are transmitted for the light.

      The fractal optical modulator contains two patterns, the pattern two can be used to detect the target, and pattern one can be used to lock the target

The best similarity of MTF behavior for normal and fractal Reticle was evaluating the power transparent depends on the size o

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Publication Date
Tue May 16 2023
Journal Name
Journal Of Engineering
Adaptive Coded Modulation for OFDM System
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This paper studies the adaptive coded modulation for coded OFDM system using punctured convolutional code, channel estimation, equalization and SNR estimation. The channel estimation based on block type pilot arrangement is performed by sending pilots at every sub carrier and using this estimation for a specific number of following symbols. Signal to noise ratio is estimated at receiver and then transmitted to the transmitter through feedback channel ,the transmitter according to the estimated SNR select appropriate modulation scheme and coding rate which maintain constant bit error rate
lower than the requested BER. Simulation results show that better performance is confirmed for target bit error rate (BER) of (10-3) as compared to c

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Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Lorenz model and chaos masking /addition technique
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Publication Date
Mon Apr 01 2002
Journal Name
Renewable Energy
The optoelectronic properties of CdSe:Cu photoconductive detector
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Publication Date
Sun May 07 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Theoretical Calculation of Reorientation Energy in Metal /Semiconductor Interface
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A theoretical calculation of the reorientation energy for non adiabatic electron transfer at
interface between metal and semiconductor system was carried out. The continuum outer
sphere theory of electron transfer reaction has been extensively used for electron transfer
between metal/semiconductor interface .It is found that in these calculations the reorientation
energy is proportional to the optical and statistical dielectric constant of semiconductor ,
properties of metal ,and the distance between metal and semiconductor .Results of
reorientation energy show that ZnO semiconductor with metal Au possess a good matching as
compared with ZnS and ZnSe . Theoretical calculation showed a good agreement with
ex

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Publication Date
Mon May 15 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Spot Size on the Fractal Optical Modulation
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The present paper analyzes the signal emitting from the Reticle during changing the spot size of laser falling on the disk and shows the optimum frequency and the amount of energy window in different patterns of modulator (Reticle).  All results are obtained by establishing   a special program named “Disk optical modulator version 3" using the language visual basic 6 ahich contains many parameters. All models of optical modulator consist of twenty sectors, ten sectors are opaque and other ten sectors are transmitted for the laser. The number of sectors depends on several factors as chopping frequency, power transparent and modulation transfer function.   It has been demonstrated by simulations, the optimal

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Publication Date
Fri Jan 31 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The Systemic Host Modulation Therapy of Periodontal Diseases
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Background: The systemic host modulation therapy is new approach in treatment of periodontal diseases. Materials and methods:The target of this treatment is the host response to microbial infection because at present time,it is well known that most of damage found in periodontal diseases cause by the inflammatory -immune response to periodontal infections.Sub-antimicrobial-dose Doxycycline (SDD) is a 20-mg dose of Doxycycline (Periostat) that is approved and indicated as an adjunct to scaling and root planning (SRP) in the treatment of chronic periodontitis. Results:At present, SDD (Periostat) is the only systemically administered agent that is approved by the U.S. Food and Drug Administration (FDA) and accepted by the American Dental Asso

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Publication Date
Thu Jun 01 2023
Journal Name
Sustainable Engineering And Innovation
A review of enhanced image techniques using chaos encryption
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Secured multimedia data has grown in importance over the last few decades to safeguard multimedia content from unwanted users. Generally speaking, a number of methods have been employed to hide important visual data from eavesdroppers, one of which is chaotic encryption. This review article will examine chaotic encryption methods currently in use, highlighting their benefits and drawbacks in terms of their applicability for picture security.

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Publication Date
Mon Apr 15 2019
Journal Name
Proceedings Of The International Conference On Information And Communication Technology
Hybrid LDPC-STBC communications system based on chaos
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Publication Date
Thu Nov 01 2001
Journal Name
Renewable Energy
Optoelectronic properties of a-Si1−xGex:H thin films
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