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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
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
Imported inflation ... concept, transmission channels, effects, and processors Iraq Case study for the period (1990-2015)
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This research aims to explain the effect of the imported inflation (which moves through the raise of global prices to Iraqi economy) over local prices, besides, the recognition the most important channels of imported inflation moving, its causes, effects, ways and policies that reduce the negative effects. To achieve the research aim, the deductive approach was adopted through using descriptive method to describe and determine phenomenon. The most important conclusion is that the research found out that there are two channels to transmission imported inflation in world. The first channel is the direct channel (prices) and the second channel is the indirect (income). The most important recommendation is to create sovereign fund (O

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Publication Date
Sat Oct 08 2022
Journal Name
Aro-the Scientific Journal Of Koya University
Data Analytics and Techniques
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Big data of different types, such as texts and images, are rapidly generated from the internet and other applications. Dealing with this data using traditional methods is not practical since it is available in various sizes, types, and processing speed requirements. Therefore, data analytics has become an important tool because only meaningful information is analyzed and extracted, which makes it essential for big data applications to analyze and extract useful information. This paper presents several innovative methods that use data analytics techniques to improve the analysis process and data management. Furthermore, this paper discusses how the revolution of data analytics based on artificial intelligence algorithms might provide

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Publication Date
Tue Oct 08 2002
Journal Name
Iraqi Journal Of Laser
Visible Enhanced Photodetector Made by Spray Pyrolysis
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Barium–doped TiO2 / n-Si photodetector was fabricated by spray pyrolysis exhibited visible enhancement responsivity profile with peak response at 600 nm flat response between 650 and 900 nm. The quantum efficiency was 30% and specific detectivity was 5x1012 W-1Hz1/2cm at peak response. The GaAlAs laser diode was used to estimate the rise time of the detector.

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Publication Date
Sun Jan 01 1995
Journal Name
المجلة العراقية للاحياء المجهرية
NUMERICAL CHARACTERIZATION OF HALOBACTERIUM SPECIES ISOLATED FROM LOCAL HIGH SALIENT DESERTIFICATION SOILS
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ABSTRACT Fifty extremely halophilic bacteria were isolated from local high salient soils named Al-Massab Al-Aam in south of iraq and were identified by using numerical taxonomy. Fourty strains were belong to the genus Halobacterium which included Hb. halobium (10%). Hb. salinarium (12.5%), Hb.cutirubrum (17.5%), Hb-saccharovorum (12.5%), Hb. valismortis (10%) and Hb. volcanii (37.5%). Growth curves were determined. Generation time (hr) in complex media and logarithmic phase were measured and found to be 10.37±0.59 for Hb. salinarium. 6.49 ± 0.24 for Hb.cutirubrum. 6.70±0.48 for Hb-valismonis, and 11.24 ± 0.96 for Hb. volcanii

Publication Date
Sun Mar 17 1996
Journal Name
مجلة العلوم العراقية
PRIMARY CHARACTERIZATION OF MEMBRANE PROTEINS OF Halobacterium saccharovorum ISOLATED FROM LOCAL, HIGH SALINITY DESERTIFICATED SOILS
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Halobacterium saccharovorum was isolated from local highsalinity souls named Al-Massab Al-Aam. A growth curve was determined. The average generation time during logarith- mic phase was 17.80±0.62 hr. Bacteriorhodopsin was 1808 lated from the purple membrane, its concentration was 4.8 mg/ml and H.W was 26000. The pattern of other membrane Bpoteins was studied and compared with those of other Boletes. Several unique proteins were isolated and their molecular weights were determined.

Publication Date
Sun Jan 10 2016
Journal Name
British Journal Of Applied Science & Technology
Illumination - Invariant Facial Components Extraction Using Adaptive Contrast Enhancement Methods
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The process of accurate localization of the basic components of human faces (i.e., eyebrows, eyes, nose, mouth, etc.) from images is an important step in face processing techniques like face tracking, facial expression recognition or face recognition. However, it is a challenging task due to the variations in scale, orientation, pose, facial expressions, partial occlusions and lighting conditions. In the current paper, a scheme includes the method of three-hierarchal stages for facial components extraction is presented; it works regardless of illumination variance. Adaptive linear contrast enhancement methods like gamma correction and contrast stretching are used to simulate the variance in light condition among images. As testing material

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Publication Date
Fri Dec 05 2014
Journal Name
Rwth Aachen University
Modeling, Walking Pattern Generators and Adaptive Control of Biped Robot
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Biped robots have gained much attention for decades. A variety of researches has been conducted to make them able to assist or even substitute for humans in performing special tasks. In addition, studying biped robots is important in order to understand the human locomotion and to develop and improve control strategies for prosthetic and orthotic limbs. Some challenges encountered in the design of biped robots are: (1) biped robots have unstable structures due to the passive joint located at the unilateral foot-ground contact. (2) They have different configuration when switching from walking phase to another. During the singlesupport phase, the robot is under-actuated, while turning into an over-actuated system during the double-support pha

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Publication Date
Sun Jan 01 2017
Journal Name
Journal Of Engineering
Adaptive Sliding Mode Controller for Servo Actuator System with Friction
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This paper addresses the use of adaptive sliding mode control for the servo actuator system with friction. The adaptive sliding mode control has several advantages over traditional sliding mode control method. Firstly, the magnitude of control effort is reduced to the minimal admissible level defined by the conditions for the sliding mode to exist. Secondly, the upper bounds of uncertainties are not required to be known in advance. Therefore, adaptive sliding mode control method can be effectively implemented. The numerical simulation via MATLAB 2014a for servo actuator system with friction is investigated to confirm the effectiveness of the proposed robust adaptive sliding mode control scheme. The results clarify, after

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
A Parallel Adaptive Genetic Algorithm for Job Shop Scheduling Problem
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Publication Date
Tue Aug 31 2021
Journal Name
Karbala International Journal Of Modern Science
Adaptive reconstruction of the heterogeneous scan line ETM+ correction technique
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