Preferred Language
Articles
/
alkej-590
New Adaptive Data Transmission Scheme Over HF Radio
...Show More Authors

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.

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Estimating concentration of toxic ions Arsenic in water by using Photonic Crystal Fiber based on Surface Plasmon Resonance (SPR)
...Show More Authors

In this work, an enhanced Photonic Crystal Fiber (PCF) based on Surface Plasmon Resonance (SPR) sensor using a sided polished structure for the detection of toxic ions Arsenic in water was designed and implemented. The SPR curve can be obtained by polishing the side of the PCF after coating the Au film on the side of the polished area, the SPR curve can be obtained. The proposed sensor has a clear SPR effect, according to the findings of the experiments. The estimated signal to Noise Ratio (SNR), sensitivity (S), resolution (R), and Figures of merit (FOM) are approaching; the SNR is 0.0125, S is 11.11 μm/RIU, the resolution is 1.8x〖10〗^(-4), and the FOM is 13.88 for Single-mode Fiber- Photonic Crystal Fiber- single mode Fiber (SMF-P

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (4)
Scopus Crossref
Publication Date
Wed Feb 22 2023
Journal Name
مجلة علوم الرياضة
دراسة عاملية للأدلة والقوة العضلية والسرعة لعدائي(110) متر حواجز بحث مسحي على عدائي 110 متر حواجز
...Show More Authors

View Publication Preview PDF
Publication Date
Sat Feb 14 2026
Journal Name
Karbala Journal Of Physical Education Sciences
تأثير تمرينات وقائية للذراعين في تطوير بعض القدرات البدنية للاعبي المنتخب الوطني بكرة السلة على الكراسي المتحركة
...Show More Authors

View Publication Preview PDF
Publication Date
Tue Jun 08 2021
Journal Name
مجلة العلوم و التكنولوجية للنشاطات البدنية و الرياضية
The effectiveness of using (7E’s) learning cycle in learning a movement chain on the uneven bars in the artistic gymnastics for women
...Show More Authors

Abstract The Object of the study aims to identify the effectiveness of using the 7E’s learning cycle to learn movement chains on uneven bars, for this purpose, we used the method SPSS. On a sample composed (20) students on collage of physical education at the university of Baghdad Chosen as two groups experimental and control group (10) student for each group, and for data collection, we used SPSS After collecting the results and having treated them statistically, we conclude the use 7E’s learning cycle has achieved remarkable positive progress, but it has diverged between to methods, On this basis, the study recommended the necessity of applying 7E’s learning cycle strategy in learning the movement chain on uneven bar

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 31 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
تطبيق برنامج مقترح لتدقيق عمليات استكشاف الموارد المعدنية وتقييمها على وفق متطلبات معيار الابلاغ المالي رقم (6)
...Show More Authors

Review of the research and the reality of the costs of the survey and exploration in the oil exploration company The study showed the effect of the application of standard financial reporting (6) "mineral resources exploration and evaluation" on the financial statements, have touched on a range of problems, the most important deficiencies in the disclosure of information relating to expenses of research and exploration that must be show Kmugod and which should be recognized as an expense in the financial statements of the company based on the international standard (6) for the purpose of knowing the financial situation of the company, and to find solutions presented researcher hypothesis is the following: that the Company's application s

... Show More
View Publication Preview PDF
Publication Date
Mon Sep 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Manual proposal to audit the automated accounting system in accordance with the framework (COBIT): Applied Research in the General Company for Petrochemical Industries
...Show More Authors

The information revolution، the new language has become one for all the peoples of the world through handling and exchange and to participate in all key areas (economic، cultural and scientific) and Accounting episode of this revolution has turned most of the traditional systems (manual) in companies to automated systems، this transformation in the regulations summoned from the auditors that develops their traditional examination automated systems so had to provide tools for auditing help auditors to keep abreast of developments and as a result there is no evidence checksum Local Private audited automated systems came search to provide evidence helps auditors for guidance as part of COBIT، which provides audit procedures Detailed inf

... Show More
View Publication Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
مجلة المستنصرية لعلوم الرياضة
علاقة السرعة الحركية بالاستحواذ على الكرة ودقة المناولة للاعبي مراكز الموهبة بكرة القدم بأعمار 12 – 14 سنة
...Show More Authors

Publication Date
Mon Dec 01 2008
Journal Name
Al-khwarizmi Engineering Journal
Effect of Chloride Ions on the Corrosion Behavior of Al – Zn Alloy in NaOH Solution at Four Different Temperatures
...Show More Authors

This research involves study effect of chloride ions in concentration range (0.01 – 0.50 mol.dm-3) on the corrosion behavior of Al-Zn alloy in basic media of 1x10-3 mol.dm-3 NaOH at pH=11 and four different temperatures in the range (298-313 K). Cathodic and anodic Tafel slopes (bc &ba) and transfer coefficients (αc & αa) were calculated and the results interprets according to the variation of the rate – determining steps. The results also indicate that the chloride ions are bonded chemically in the interface as an initial step of formation of different mixed oxohydroxy – and chloro complexes. Polarization resistance (Rp) is calculates

... Show More
View Publication Preview PDF
Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Genetic Algorithm Based PID Controller Design for a Precise Tracking of Two-Axis Piezoelectric Micropositioning Stage
...Show More Authors

 In this paper, an intelligent tracking control system of both single- and double-axis Piezoelectric Micropositioner stage is designed using Genetic Algorithms (GAs) method for the optimal Proportional-Integral-Derivative (PID) controller tuning parameters. The (GA)-based PID control design approach is a methodology to tune a (PID) controller in an optimal control sense with respect to specified objective function. By using the (GA)-based PID control approach, the high-performance trajectory tracking responses of the Piezoelectric Micropositioner stage can be obtained. The (GA) code was built and the simulation results were obtained using MATLAB environment. The Piezoelectric Micropositioner simulation model with th

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 04 2015
Journal Name
Journal Of Educational And Psychological Researches
Attitudes towards Mental illness among Pregnant Women AttendinGovernment on Women's Clinics in the Province of Ramallah and Al-Bireh
...Show More Authors

This study aimed to identify attitudes towards mental illness in pregnant female clients to clinics women in the province of Ramallah and Al Bireh, for this purpose applied to study procedures on a sample of (200) of pregnant mothers were selected a sample available, have reached results no statistically significant differences in the level of attitudes towards mental illness due to the variable age in mothers pregnant female clients to clinics for women. Ther were astatistically significant differences in the level of these trends depending on the variable-level scientific research for the benefit of pregnant class university students and older and then high school and so on all areas except the area of social interaction, The results a

... Show More
View Publication Preview PDF