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joe-1095
Pilot Based Channel Estimation and Synchronization in OFDM System
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Channel estimation and synchronization are considered the most challenging issues in Orthogonal Frequency Division Multiplexing (OFDM) system. OFDM is highly affected by synchronization errors that cause reduction in subcarriers orthogonality, leading to significant performance degradation. The synchronization errors cause two issues: Symbol Time Offset (STO), which produces inter symbol interference (ISI) and Carrier Frequency Offset (CFO), which results in inter carrier interference (ICI). The aim of the research is to simulate Comb type pilot based channel estimation for OFDM system showing the effect of pilot numbers on the channel estimation performance and propose a modified estimation method for STO with less number of pilot to mitigate ISI effect. Channel estimation is simulated for different pilot number with 16QAM modulation in Ped-A Rayleigh channel. The STO effect assumed less than the cyclic prefix length to minimize ISI and maintain the orthogonality between subcarriers. The simulation results show that the high number of pilots are needed to achieve good channel estimation in case no synchronization used while similar results are achieved with smaller number of pilots if the propose modification on the synchronization method are used aligned with the channel estimation. The proposed system is evaluated in terms of BER and SNR.

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Publication Date
Thu Apr 18 2019
Journal Name
Al-kindy College Medical Journal
Predictors of poor first trimester outcome in asymptomatic women : the value of embryonic heart rate , mid sac diameter / yolk sac ratio & mid sac diameter / crown rump length
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Background:  Ultrasound provides a powerful tool for assessing early pregnancy and detecting pregnancy failure at first trimester and promoting rapid effective management. Several  criteria have been established  to predict  the pregnancy outcome particularly in symptomatic women .

Aim: To evaluate  asymptomatic women at the first trimester of pregnancy , to assess the efficacy of certain ratios as mid sac diameter (MSD)  / yolk sac ratio & crown rump length (CRL)/mid sac diameter (as indicator  of early first trimester oligohydramnios)  in predicting poor 1st   trimester outcome

Type of the study: A cross-s

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Publication Date
Mon Jan 01 2018
Journal Name
Al–bahith Al–a'alami
The Role of TV Programs in Spreading the Culture of Community for Peace: Studying the Attitudes of the Publics towards a Program entitled Mosamih Kareem on YouTube
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The fundamental problem in determining the role of television programs in broadcasting the culture of community for peace through studying almosamig kareem program by studying the topics addressed in this program. It is a descriptive study and it follows the approach survey method.  In this study, the spatial framework is limited to the program of almosamih kareem on YouTube, while the temporal framework is concerned with the episodes that are raised on YouTube from the second half of 2014 to 2015 of almosamih kareem program. The fundamental problem in determining the role of television programs in broadcasting the culture of community for peace through studying almosamig kareem program by studying the topics addressed in this

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Publication Date
Sun Jan 01 2023
Journal Name
International Journal Of Economics And Finance Studies
THE ROLE OF TARGET COST MANAGEMENT APPROACH IN REDUCING COSTS FOR THE ACHIEVEMENT OF COMPETITIVE ADVANTAGE AS A MEDIATOR: AN APPLIED STUDY OF THE IRAQI ELECTRICAL INDUSTRY
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Publication Date
Sat Nov 11 2023
Journal Name
Journal Of Dental Research, Dental Clinics, Dental Prospects
Investigating the effect of Er,Cr:YSGG laser agitation of sodium hypochlorite on the removal of mature biofilm in the complex root canal systems using atomic force microscopy
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Background. Endodontic infections caused by remaining biofilm following disinfection with chemical fluids encourage secondary bacterial infection; hence, employing laser pulses to activate the fluids is advised to improve microbial biofilm clearance. This study investigated the performance of Er,Cr:YSGG laser in photon-induced photoacoustic streaming (PIPS) agitation of 5.25% sodium hypochlorite (NaOCl) to enhance the removal of mature Enterococcus faecalis (E. faecalis) biofilms in complex root canal systems. Methods. The mesial roots of the lower first and second molars were separated and inoculated with E. faecalis bacteria for 30 days. The roots were irrigated with 5.25% NaOCl, some of them were agitated with passive ultrasonic

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Publication Date
Sun Mar 01 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Impact assessment of strategic goods on government grants and as a result of activity: An analytical study at the General Company of grain trading
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  In Iraq,  government contributions to the public companies have become a very important aspect which contributes to the survival and sustainability of these institutions as it consider  one of the main sources of funding, if not it consider the basis of funding.

  According to  the vital roles assigned to these institutions to follow up, which usually  include important activities in the national economy, the research focused on studying the field reality of the method used in evaluating the stock of total production and purchases of goods for the purpose of selling the strategic commodities of the General Company for Grain Trade.  As a result, the aim of this study came to came to highlight&n

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Publication Date
Sat Dec 28 2024
Journal Name
Journal Of Physical Education
The Effect of a Psychological Counseling Program to reduce irrational ideas and the causal attribution of the coaches of the gymnasium sports care center
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The research aimed to prepare a psychological counseling program for the coaches of the Sports Care Center in the gymnasium, and to learn about the impact of the psychological counseling program in reducing irrational ideas and causal attribution of the coaches of the Sports Talent Care Center in the gymnasium, to assume that there are statistically significant differences between the results of the tribal and posttests of the research group Experimental in the scale of irrational ideas, and there are statistically significant differences between the results of the tribal and posttests of the experimental research group in the scale of the causal attribution scale, The experimental approach was adopted by designing one experimental

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Publication Date
Tue Jan 01 2019
Journal Name
Research Journal Of Pharmacy And Technology
Effect both of Kinetin and NPKZn Fertilizer on Mitigating The Adverse effect of Sodium Chloride on sweet pepper plant <i>Capsicum annuum</i> L.
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The experiment was carried out in the green house of botanical garden belong to Department of Biology/College of Education for Pure Science- Ibn–al- Haitham/University of Baghdad, for the growth season 2015 using plastic pots. The experiment aimed to study the effect of two concentrations of sodium chloride (50, 100) mM.L-1 in addition to the control and four concentrations of kinetin (25, 50, 75, 100) mg.L-1 in addition to the control and the influence of application and non application of fertilizlizer NPKZn in the level 160 kg.h1- and their interactions on some growth parameters (fresh weight for both root and vegetative part, dry weight for leaves , value of secondary productivity, biomass duration for vegetative part and dry weight f

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Publication Date
Sun Jun 01 2014
Journal Name
International Journal Of Physics And Research (ijpr)
CALCULATIONS OF MOLTIPOLE MIXING RATIOS FOR GAMMA TRANSITIONS OF Yb POPULATED FROM Yb REACTION USING -RATIO, CONSTANT STATISTICAL TENSOR AND LEAST SQUARES FITTING METHODS
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The - mixing ratios of -transitions from levels in populated in the reactions are calculated in present work using - ratio, constant statisticalTensor and least squares fitting methods The results obtained are in general, in good agreement or consistent, within the associated uncertainties, with these reported in Ref.[9],the discrepancies that occurs are due to inaccuracy existing in the experimental data The results obtained in the present work confirm the –method for mixed transitions better than that for pure transition because this method depends only on the experimental data where the second method depends on the pure or those considered to be pure -transitions, the same results occur in – method

Publication Date
Tue May 30 2023
Journal Name
Dirasat: Human And Social Sciences
The Family of Minister Al-Sayyid Al-Ajall: A Study of Its Political, Administrative, and Urban Role (7th-8th Century AH / 13th-14th AD)
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Objectives: The study aimed to clarify the role of Al-Sayyid Al-Ajall and his family in the service of the Mongol Empire. They worked to develop its administrative and military institutions, benefiting from their extensive experience in administration, politics, economics, and urban affairs. Due to their capabilities, they received the patronage of Genghis Khan and subsequent generations, earning the confidence of the ruling Mongol authority. As a result, they were granted significant powers within the state.       Methods: The study relied on the analytical method to analyze historical texts, compare them with others, and discuss them accurately. Results: The study yielded several results, including the minister's keen interes

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Publication Date
Wed May 01 2024
Journal Name
Journal Of Physics: Conference Series
A study of the Electrical and Dialectical proprieties of S<sub>60-</sub>Se<sub>40-X</sub>-Pb<sub>X</sub>Chalcogenide Compound
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Abstract<p>In this study, the melting-cooling method was used to prepare the chalcogenide compound S<sub>60</sub>-Se<sub>40-X</sub>-Pb<sub>X</sub>. Four samples were obtained by partial replacement of Selenium with Lead in the weight ratios x = 0, 10, 20, and 30, respectively. The materials were mixed separately, ground, placed in quartz ampoules, and heated to 500 degrees Celsius. After conducting several operations on the samples, their insulating properties were studied, represented by the real dielectric constant and the imaginary dielectric constant, and the electrical conductivity was measured as a function of the frequency. It was found that partial replacement plays an impo</p> ... Show More
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