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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 Apr 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Analsis of politic behavior and its impact on displaying the continuousness of organizational trust mantainance ,applied research of a sample of AL-farouq State Construction contracting company Employees
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The research aims to know the concept of politic behavior as one of the important behaviours in the different fields and sectors. It is considered to be part of the organizatial work to face the expected  risks. It includes two group of factors personal (self –monitors, locus of control ,expectation s of success, perceived job alternatives)and organizational(promotion ,division resources,role  ambiguity ,democratic decision)studied by the researcher  in the frame of the relationship with the variable  of display  continuous trust matain which includes two variable (build trust mantain, display  trust continuouness)through applied frame by random sample consists of (90)employee  at Farouq State

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Publication Date
Fri Jan 03 2020
Journal Name
مجلة القادسية في الآداب والعلوم التربوية
The Effectiveness of a Teaching Style Based on the Brunner Model in the Achievement and Retention of Grammar Material for Students of the Arabic Language Department at the Faculty of Education for Girls
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This research aims to find out the impact on the receptive style according to the specimen in the collection of material Brawner and retention as students at the Arabic Department at the Faculty of Education for Girls. For confirmation from the goal of the research, the researcher placed two hypotheses, one to two for collections and one for pods. - chosen as the College of Education for Girls / Department of Arabic language for the application of choice Intentionally search experience for reasons of researcher he is teaching them and thus ensures cooperation of teachers and students in them. - selected Division (b) of the fourth grade students of the Arabic language section at random to represent the experimental group, while the Division

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Publication Date
Fri Sep 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Studying the Effect of Addition Particles of Alumina (Al2O3) and Zirconia (ZrO2), on Some Mechanical Properties for Matrix Composites (Al-Si-Mg) Alloy
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This study is concerned with the effect of adding two kinds of ceramic materials on the mechanical properties of (Al-7%Si- 0.3%Mg) alloy, which are zirconia with particle size (20μm > P.S ≥ 0.1μm) and alumina with particle size (20μm > P.S ≥ 0.1μm) and adding them to the alloy with weight ratios (0.2, 0.4, 0.6, 0.8 and 1%). Stirring casting method has been used to make composite material by using vortex technique which is used to pull the particles to inside the melted metals and distributed them homogenously.

After that solution treatment was done to the samples at (520ºC) and artificial ageing at (170ºC) in different times, it has been noticed that the values of hardness is increased with the aging time of the o

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Economics And Administrative Sciences
Crisis management according to the strategic leadership - the interactive role of decision support systems. (An exploratory study at the Ministry of Industry and Minerals / the State Company for Steel Industries)
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The researcher aims to Diagnose the reality of research variables, strategic leadership and decision support systems, and their impact on crisis management in the General Company for Steel Industries because of their important role in preventing crises and reducing their occurrence for the research company in particular and other companies in general affiliated with the Ministry of Industry and Minerals, as well as clarifying theoretical concepts of research variables As it included the answer to questions related to the research problem, including (Is there an impact of the strategic leadership in managing crises if decision support systems are used), and the researcher adopted the descriptive and analytical approach in its comp

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Publication Date
Fri Dec 14 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Effectiveness of Health Education Program for Type 2 Diabetes Mellitus Patient's Self-efficacy toward Managing Feet at Endocrinology and Diabetes Center in Al-Rusafa Sector
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Objective(s): to assess the effectiveness of educational program on improving diabetic foot self-efficacy concerning managing their feet. Methodology: A descriptive analytic (quasi – experimental) design study was carried out at Diabetic and Endocrinology Center in Baghdad- Rusafa Sector from 2nd of May 2017, to27th June 2018. Non-probability sample of (80) male and female diabetic patients were selected. The study instruments consisted of two major parts: first

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Publication Date
Mon Oct 01 2018
Journal Name
Al–bahith Al–a'alami
The role of social networking sites of Iraqi satellite channels in prioritizing the public “Field study for the public of Dhi Qar governorate
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The study titled “The role of the social media sites of Iraqi satellite channels in prioritizing the public” is a field study for the public of Dhi Qar.
The emergence of the social networking sites we are currently experiencing has undergone radical and important changes in the role of the mass media in light of the growth and rapid spread of modern technologies Or the so-called new media، which led the media organizations to create satellite channels on the social networks، which led to bypass the traditional lines between the public and media institutions with the public gain the possibility of The purpose of the research is to determine the habits and patterns of public use of the social media sites of the Iraqi satellite cha

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Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
"The relationship between the profits management and profits quality and their impact on users of accounting information (A comparative study of a sample of banks listed in the Iraqi market for securities)
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The aim of the research is to determine the impact of profit management practices on the quality of profits through the use of flexibility in determining accounting methods and practices profit information is one of the most important information that concerns current users in general and observing users in particular. Some corporations managements manipulate the results of the company's profit or loss (income statement) and financial position statement with multiple reasons, including capital market motivations to raise their share prices in the stock market and attract investors, and on the other hand the motives of funding and borrowing loans, and the use of the flexibility in accounting policies and estimates to change the in

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Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Laser
Experimental Study of Spatial Self-Phase Modulation (SSPM) Based on Laser Beam and Hybrid Functionalized Carbon Nanotubes/Silver Nanoparticles (F-Mwcnts/Ag-Nps) Acetone Suspensions
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Focusing of Gaussian laser beam through nonlinear media can induce spatial self- phase modulation which forms a far field intensity pattern of concentric rings. The nonlinear refractive index change of material depends on the number of pattern rings. In this paper, a formation of tunable nonlinear refractive index change of hybrid functionalized carbon nanotubes/silver nanoparticles acetone suspensions (F-MWCNTs/Ag-NPs) at weight mixing ratio of 1:3 and volume fraction of 6x10-6 , 9x10-6 , and 18x10-6 using laser beam at wavelength of 473nm was investigated experimentally. The results showed that tunable nonlinear refractive indices were obtained and increasing of incident laser power density led to increase the nonlinear refractive inde

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Publication Date
Sun Jul 17 2022
Journal Name
Al–bahith Al–a'alami
Features of news coverage during Covid-19 crisis: Content analysis on a sample of global news accounts on Twitter
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This study aims to analyze the messages of a number of global news outlets on Twitter. In order to clarify the news outlets tactics of reporting, the subjects and focus during the crisis related to the spread of the Covid-19 virus. The study sample was chosen in a deliberate manner to provide descriptive results. Three news sites were selected: two of the most followed, professional and famous international news sites: New York Times and the Guardian, and one Arab news site: Al-Arabiya channel.

A total of 18,085 tweets were analyzed for the three accounts during the period from (1/3/2020) to (8/4/2020). A content analysis form was used to analyze the content of the news coverage.   The results indicate an increase in th

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Publication Date
Mon Oct 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Studying the effect of institutional pressures on the attitudes of the managers of small enterprises in Thi-Qar province toward intention continuance environmental disposal of e-waste
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       Currently, there is no established of e-waste treatment in Thi- Qar province, while their creating is increasing every year. It has been well- known that e-waste is a source of environmental degrading and their placement in landfills increases the irreversible climate change. A research model has been developed to link three components: coercive pressure, normative influence, and mimicry, then study their effect on e-waste adopt and continuance intentions. The model was validated using data collected from a field survey of 92 managers of small enterprises in Thi-Qar province.  A questionnaire was developed to collect data. It contains five major variables, exemplify by fourteen items. Als

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