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320 Gbps Free Space Optic Communication System Deploying Ultra Dense Wavelength Division Multiplexing and Polarization Mode Division Multiplexing
Abstract<p>This work aims to investigate the integrated ultra-dense wavelength division multiplexing (UDWDM) and polarization division multiplexing (PDM) schemes incorporated in the free space optic (FSO) communication system. Erbium-doped fiber amplifiers (EDFAs) are used as post and pre-amplifiers in the proposed UDWDM–PDM–FSO system to boost the transmission power for increasing the distance. Thirty-two channels are transported over the FSO link to realize the total data transmission of 160 and 320 Gbps with 0.08 and 0.1 nm channel spacing, respectively. Results are also reported with non-return to zero modulation schemes. The performance of the proposed UDWDM–PDM–FSO transmission system is measured in terms of bit error rate (BER) and eye diagrams. The transmission distances are 100 and 87 km under clear weather and have acceptable BERs with 0.08 and 0.1 nm channel spacing, respectively. The weather conditions may worsen due to the increase in atmospheric turbulence. Hence, the transmission distances decrease to 3.93 and 2.6 km for heavy rain weather conditions. The UDWDM–PDM–FSO communication system exhibits an excellent performance due to the use of EDFAs with high achievable maximum distance and good and acceptable BER performance. The UDWDM–PDM–FSO communication system considerably enhances the transmission distance compared with the UDWDM–FSO communication system.</p>
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Publication Date
Mon Jun 01 2009
Journal Name
2009 Etp International Conference On Future Computer And Communication
Ultra Wideband Cognitive Network Objective Issues

Due to that the Ultra Wide Band (UWB) technology has some attractive features like robustness to multipath fading, high data rate, low cost and low power consumption, it is widely use to implement cognitive radio network. Intuitively, one of the most important tasks required for cognitive network is the spectrum sensing. A framework for implementing spectrum sensing for UWB-Cognitive Network will be presented in this paper. Since the information about primary licensed users are known to the cognitive radios then the best spectrum sensing scheme for UWB-cognitive network is the matched filter detection scheme. Simulation results verified and demonstrated the using of matched filter spectrum sensing in cognitive radio network with UWB and pro

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Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
High Order Sliding Mode Observer-Based Output Feedback Controller Design For Electro-Hydraulic System

A perturbed linear system with property of strong observability ensures that there is a sliding mode observer to estimate the unknown form inputs together with states estimation. In the case of the electro-hydraulic system with piston position measured output, the above property is not met. In this paper, the output and its derivatives estimation were used to build a dynamic structure that satisfy the condition of strongly observable. A high order sliding mode observer (HOSMO) was used to estimate both the resulting unknown perturbation term and the output derivatives. Thereafter with one signal from the whole system (piton position), the piston position make tracking to desire one with a simple linear output feedback controller after ca

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Publication Date
Tue Nov 19 2024
Journal Name
Journal Of Physical Education
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Publication Date
Wed May 31 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Histological Study on Optic Tectum in Hemida ctylus Flaviviridis

  A histological study was conducted to examine the structure of optic tectum in Hemidactylus flaviviridis. The results showed that the optic tectum consists of fourteen strata organized in three zones. The deep zone which extends from the first stratum (around optic ventricle) to the fifth stratum. The medium zone comprises the sixth & seventh strata, which represent the center of optic tectum. The superficial zone which extends from the eighth stratum to the fourteenth stratum and forms the retino recipient region.         The strata of deep zone are called the Stratum Griseum et Periventricular ( SGAP ) , the sixth stratum  is  called the Stratum Album Central ( SAC ) and&nbsp

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Publication Date
Fri Jul 01 2016
Journal Name
Al–bahith Al–a'alami
Semiotics and Communication

Verbal Communication is linked with the social event no matter how different Communities in their cultures and styles of living and it's intuitions and political systems remain involved in its need . It is a dialogue , a pillar of human Communication , all Communication process conditional on the where a bouts of the shrine and the cycle of words . Semiotics is based on two principles important to Communicate : one : offer intended to report to the speaker . And the other : The recipient of the message a (know led gment of this intent . And learn to measure intent rely on two types of units ; first is the evidence for which is available for reporting the intent and the other : Signals . semiotics Communicate evidence bother as a channel

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Publication Date
Wed Feb 05 2020
Journal Name
Political Sciences Journal
International and regional alliances polarization.. Case study IRAQ

Abstract Iraq has an important place in the regional and international balance, and the competition among countries has increased in rapprochement with Iraq, not only for its geography or its privileged location, but because it has many other components that make regional and international countries want to strengthen their relations with it (Regional and international powers). In addition to that, Iraq has become increasingly important for these international and regional powers after its victory over the terrorist organization (ISIS), which proved an important fact that Iraq represents the most important pillars in the international balance.

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Publication Date
Wed Dec 18 2019
Journal Name
Baghdad Science Journal
Effect of Refractive Index on Photon Natural Mass and Wavelength

In this article it is proved experimentally that the photon is a particle that has mass and constant wavelength by explaining the effect of refractive index on the wavelength and the natural mass of photon. It is very difficult to measure the mass of photon, a simple and easy process was proposed in this paper to calculate the mass length of photon in vacuum (Y) and in medium (Y*), by measuring the length of laser beam in air (Lair) and in medium (Lmed). A new method was postulated to calculate refractive index by using these relations (n = Y*/Y), and (n = Lmed / Lair) which supposed a new theory of light.

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Publication Date
Thu Apr 28 2022
Journal Name
Iraqi Journal Of Science
Multi-wavelength studies of NGC 4425 Galaxy

In this work, ugzri images of NGC 4425 galaxy are analyzed. The galaxy images are obtained from the seventh Sloan Digital Sky Survey (SDSS) Data Release (DR7). This work was performed with Image Reduction and Analysis Facility (IRAF) and analyzed the structure of the galaxy a bulge, a bar, together with isophotal contour maps and performed a bulge/disk decomposition of the galaxy image. Also, we have estimated the disk position angle, ellipticity, B4 and inclination of the galaxy.

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Publication Date
Sun Jan 04 2015
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Dense breast as a risk factor in breast malignancy

Background: One of the strongest risk factors for breast cancer is high breast density, relatively little fat in the breast and more connective and glandular tissue.
Objectives: this study aims to measure risk of increase breast density in correlation of CA breast & compare our results with results in other population, to compare the performance of ultrasonography and mammography in measuring breast density according to BIRDS system
Materials &methods: The study included 45 females .Measuring risk of increase breast density in correlation of CA breast & comparing the performance of ultrasonography and mammography in measuring breast density according to BIRADS system.
Results : there is stron

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Publication Date
Thu Dec 14 2023
Journal Name
Iete Journal Of Research
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