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New Adaptive Data Transmission Scheme Over HF Radio
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Acceptable Bit Error rate can be maintained by adapting some of the design parameters such as modulation, symbol rate, constellation size, and transmit power according to the channel state.

An estimate of HF propagation effects can be used to design an adaptive data transmission system over HF link. The proposed system combines the well known Automatic Link Establishment (ALE) together with variable rate transmission system. The standard ALE is modified to suite the required goal of selecting the best carrier frequency (channel) for a given transmission. This is based on measuring SINAD (Signal plus Noise plus Distortion to Noise plus Distortion), RSL (Received Signal Level), multipath phase distortion and BER (Bit Error Rate) for each channel in the frequency list. Channel condition evaluation is done by two arrangements. In the first an FFT analysis is used where a pilot signal is transmitted over the channel, while the data itself is used in the second arrangement. Passive channel assessment is used to avoid bad channels hence limiting the frequency pool size to be used in the point to point communication and the time required for  scanning and linking. An exchange of channel information between the transmitting and receiving stations is considered to select the modulation scheme for transmission. Mainly MPSK and MFSK are considered with different levels giving different data rate according to the channel condition. The results of the computer simulation have shown that when transmitting at a fixed channel symbol rate of 1200 symbol/sec, the information rate ranges from 2400 bps using 4FSK up to 3600 bps using 8PSK for SNR ranges from 11dB up to 26dB.

 

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Publication Date
Tue Dec 29 2020
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Synthesis, Characterization, and Antibacterial Evaluation of New Vanillic Acid Derivatives
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Publication Date
Sun Jul 01 1990
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
DESCRIPTION OF NEW SPECIES OF TERMITES (INSECTA, ISOPTERA) FROM IRAQ
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Two specie's of terrnitls are described as new to science from Iraq Amitermes corpnlentus sp. n. and Anacanthotermes savvensis sp. n., with two figures.

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Publication Date
Tue Jun 01 2021
Journal Name
Gene Reports
Cystatin D as a new diagnostic marker in rheumatoid arthritis
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Publication Date
Mon Jan 01 2024
Journal Name
Nonlinear Functional Analysis And Applications
NEW SEVEN-PARAMETER MITTAG-LEFFLER FUNCTION WITH CERTAIN ANALYTIC PROPERTIES
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In this paper, a new seven-parameter Mittag-Leffler function of a single com-plex variable is proposed as a generalization of the standard Mittag-Leffler function, certain generalizations of Mittag-Leffler function, hypergeometric function and confluent hypergeometric function. Certain essential analytic properties are mainly discussed, such as radius of convergence, order, type, differentiation, Mellin-Barnes integral representation and Euler transform in the complex plane. Its relation to Fox-Wright function and H-function is also developed.

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
A New Hybrid Meta-Heuristics Algorithms to Solve APP Problems
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Abstract<p>In this paper, a new hybrid algorithm for linear programming model based on Aggregate production planning problems is proposed. The new hybrid algorithm of a simulated annealing (SA) and particle swarm optimization (PSO) algorithms. PSO algorithm employed for a good balance between exploration and exploitation in SA in order to be effective and efficient (speed and quality) for solving linear programming model. Finding results show that the proposed approach is achieving within a reasonable computational time comparing with PSO and SA algorithms.</p>
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Publication Date
Sun Nov 01 2020
Journal Name
Iop Conference Series
Modified PRESENT Encryption algorithm based on new 5D Chaotic system
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Cryptography is a major concern in communication systems. IoE technology is a new trend of smart systems based on various constrained devices. Lightweight cryptographic algorithms are mainly solved the most security concern of constrained devices and IoE systems. On the other hand, most lightweight algorithms are suffering from the trade-off between complexity and performance. Moreover, the strength of the cryptosystems, including the speed of the algorithm and the complexity of the system against the cryptanalysis. A chaotic system is based on nonlinear dynamic equations that are sensitive to initial conditions and produce high randomness which is a good choice for cryptosystems. In this work, we proposed a new five-dimensional of a chaoti

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Publication Date
Sun Sep 07 2014
Journal Name
Baghdad Science Journal
A New Operational Matrix of Derivative for Orthonormal Bernstein Polynomial's
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Publication Date
Sat Jul 01 2000
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A NEW SPECIES OF LIODONTOMERUS GAH. FROM IRAQ (HYMENOPTERA, TORYMIDAE)
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A study of the Torymid collection of Iraq. resulted in undescribed species of the genus
Liodontonierus Gah. L. longicorpus sp. n. with 2 figures.

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Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
New Commands to Improve the Monitor for the ELWE Microcomputer
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The base of the ELWE MPF-1 microcomputer is the Z80 microprocessor. The Z80 programs are written in assembly language. The main advantage of assembly language is that: it is much faster to code and the mnemonics makes it easier for the user to remember the instruction. The purpose of this paper is to improve the monitor process for didactic microcomputer ELWE MPF-1 by appending new powerful commands (MOVE, FILL, SEARCH and COMPARE) to the existing monitor to make it more useful and flexible. 8085 assembly language is used to execute this program. The letters used for abbreviation: M for MOVE, F for FILL, S for SEARCH and C for COMPARE.

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Publication Date
Fri Sep 05 2008
Journal Name
Journal Of Kerbala University
Synthesis of New type of tetrazoles starting from D-ribose
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This work includes synthesis of sugar tetrazole derivative, D-ribose reacted with acetone in the presence of sulfuric acid H2SO4 to give 2, 3-O-isopropylidene-D-ribose (1). The Aldol condensation of (1) with formaldehyde in methanolic K2CO3 solution gave 2-hydroxymethyl (2, 3-O-isopropylidene-D-ribose)(2). Which was tosylated by Tosyl chloride in pyridine to yield compound (3), SN2 reaction of (3) with sodium cyanide in DMSO afforded compound (4). The [2+ 3] cycloaddition reaction of (4) with sodium azide gave the targeted compound (5). All prepared compounds have been characterized by: TLC, Specific rotation, Microelemental analysis and [FTIR and 1 H NMR spectroscopy]