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joe-1752
Performance of STBC Based MIMO-OFDM Using Pilot-aided Channel Estimation
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Many studies have been published to address the growing issues in wireless communication systems. Space-Time Block Coding (STBC) is an effective and practical MIMO-OFDM application that can address such issues. It is a powerful tool for increasing wireless performance by coding data symbols and transmitting diversity using several antennas. The most significant challenge is to recover the transmitted signal through a time-varying multipath fading channel and obtain a precise channel estimation to recover the transmitted information symbols. This work considers different pilot patterns for channel estimation and equalization in MIMO-OFDM systems. The pilot patterns fall under two general types: comb and block types, with a proper arrangement suitable to the multiple transmit antennas. The two main channel estimation methods, LS and MMSE, are compared by evaluating performance in terms of Bit Error Rate (BER) to analyze the performance of pilot-aided channel estimation for 2x2 and 4x4 MIMO arrangements utilizing LTE parameters and the effects of modifying different numbers of OFDM subcarriers under different channel models It has been discussed, a 4x4 system performs better than a 2x2 system in terms of BER with an acceptable amount of additional complexity.

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Publication Date
Sat Mar 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Obstacles to the adoption of business commercial books to determine taxable income and ways to address them: An applied research at The General Commission for Taxes
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The research aims to shed light on the obstacles that hinder the use of taxpayers' commercial books covered by provisions of the amended commercial book-keeping system No. 2 of 1985 and ways to address these obstacles. On this basis, the main null hypothesis was formulated that there is no statistically significant relationship between the obstacles to the adoption of the commercial books and taxable income.

The research data were collected on the base of three applied case studies of registered taxpayers in the General Commission of Taxes, GCT, together with the use of a questionnaire distributed to a sample of taxpayers ( companies ). The collected data were analyzed, the result  were presented  and the hypothesis was

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Publication Date
Tue Nov 09 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Adopting the green value chain to achieve sustainable competitive advantage: study to views of a sample from Ur General Company for Engineering Industries in Dhi Qar
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       In light of the developments and intense competition that the world has witnessed, the need to search for a sustainable and continuous competitive advantage for economic units has emerged, as the economic units must not lose sight of their interest in the activities they perform to achieve that advantage, and it can be said that the goal of the research is to identify the theoretical dimensions of the green value chain represented by: (Green research and development, green design, green manufacturing, green marketing, green services) and the dimensions of the sustainable competitive advantage represented by (quality, creativity, innovation, cost, response to the customer), as well as identifyi

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Publication Date
Mon Apr 14 2014
Journal Name
Ibn Al-haitham Jour. For Pure & Appl. Sci
Synthesis and Characterization of Some O-[2-{''2-Substituted Aryl (''1,''3,''4 thiadiazolyl) ['3,'4-b]-'1,'2,'4- Triazolyl]-Ethyl]-p- chlorobenzald oxime Derivatives
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In this study new derivatives of O-[2-{''2-Substituted Aryl (''1,''3,''4 thiadiazolyl) ['3,'4-b]-'1,'2,'4- Triazolyl]-Ethyl]-p- chlorobenzald oxime (6-11)have been synthesized from the starting material p-chloro – E- benzaldoxime 1.Compound 2 was synthesized by the reaction of p-chloro – E- benzaldoxime with ethyl acrylate in basic medium. Refluxing compound 2 with hydrazine hydrate in ethanol absolute afforded 3. Derivative 4 was prepared by the reaction of 3 with carbon disulphide, treated of compound 4 with hydrazine hydrate gave 5. The derivatives (6-11) were prepared by the reaction of 5 with different substitutesof aromatic acids. The structures of these compounds were characterized from their melting points, infrared spectroscopy

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Publication Date
Mon Jun 01 2020
Journal Name
Journal Of The College Of Languages (jcl)
The adaptation and the different modifications of borrowed Arabic Plurals in Modern Turkish: Kökende Çoğul Olarak Kullanılan Arapça Kelimelerin Türkçe’ye Geçmesi ve Türkiye Türkçesinde Kullanım Şekilleri
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In the tenth century, Turks began to convert into Islam and adopted for official and literary use the Arabic language to study the teachings of the new religion they believed in. The use of  many of the loanwords have become absolute in the Ottoman period, but even in Modern Turkish a large number of loanwords from Arabic can be often recognized because they are not subject to the strict rules of Turkish. Yet, some of these words lost its original meaning and acquired new different Turkish meaning. Moreover, some of the Arabic nouns of singular form in Turkish, modified the plural Turkish form. The present study entitled “the adaptation and the different modifications of borrowed Arabic Plurals in Modern Turkish” sheds light on

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Roleof Time Management in Stages Claims Settlement of Insurance from Fire: Research Exploratory in General Iraqi Insurance Company and Private Al hamra Company for Insurance
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The insurance activity in the various countries of the world are important indicators of the strength of the country's economy, he came to study the stages compensation insurance settlement against fire and the importance of investing time risk in achieving the payment of compensation speed, and the implications for the continuation of the insured to carry out insurance with the insurance company, whether working within the public sector or the private sector. Hence the research problem in how quickly insurance companies to pay compensation as soon as possible and the return of the insured to carry out its work and make up for what he died from loss. Intentional sample was selected from branches and divisions and Their assistants manager

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Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Educational And Psychological Researches
A comparative study between the emotional responses in patients with blood pressure on a scale of music types characteristics compared with responses to some Healthy patients
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The problem of the study and its significance:

           Due to the increasing pressures of life continually, and constant quest behind materialism necessary and frustrations that confront us daily in general, the greater the emergence of a number of cases of disease organic roots psychological causing them because of severity of a lack of response to conventional treatments (drugs), and this is creating in patients a number of emotional disorders resulting from concern the risk of disease

 

     That is interested psychologists and doctors searchin

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Publication Date
Mon Dec 25 2017
Journal Name
Biomedical And Pharmacology Journal
Evaluation of Crestal Bone Loss and Alkaline Phosphatase Level in Saliva According To Different Flap Designs in Single-Tooth Dental Implant Surgery (A Clinical Comparative Study)
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Publication Date
Sat Jun 30 2018
Journal Name
College Of Islamic Sciences
Inform the people of the Enlightenment including what was said in detail In photography For Mohammed Hashim bin Ahmed footy famous Balva Hashim (Tel: 1349 e)
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Inform the people of the Enlightenment including what was said in detail
In photography
For Mohammed Hashim bin Ahmed footy famous Balva Hashim (Tel: 1349 e)

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Publication Date
Fri Mar 28 2014
Journal Name
Advances In Life Science And Technology
Synthesis and Characterization of Novel Schiff Bases, N-Acyl and Diazetines Derived from 3-((5-hydrazinyl-4-phenyl-4H-1,2,4- triazol-3-yl)methyl)-1H-indole
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This work involves synthesis of some new heterocyclic compounds including 1, 3-diazetine. The new Schiff bases [VI] ad derived from 3-((5-hydrazinyl-4-phenyl-4H-1, 2, 4-triazol-3-yl) methyl)-1H-indole [V] which was synthesized by refluxing 5-((1H-indol-3-yl) methyl)-4-phenyl-4H-1, 2, 4-triazole-3-thiol [IV] with hydrazine hydrate in absolute ethanol and this amino compound [V] condensation with different aromatic aldehydes in absolute ethanol to yielded a new Schiff bases [VI] ad. N-acyl compounds [VII] ad were synthesized by addition reaction of acetyl chloride to imine group of Schiff bases in dry benzene. The new diazetine derivatives [VIII] ad synthesized by the reaction of N-acyl compounds [VII] ad with sodium azide in dimethylformamid

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Publication Date
Tue Jul 01 2014
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A DESCRIPTION STUDY OF TWO LOCAL FISH HIMRI CARASOBARBUS LUTEUS (Heckel, 1843)(CYPRINIFORMES: CYPRINIDAE) AND HISHNI LIZA ABU (Heckel, 1843) (MUGILOIDEI : MUGILIDAE) BY BONES STAINING METHOD
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    Two local fish Himri Carasobarbus luteus (Heckel, 1843)  and Hishni Liza abu (Heckel, 1843) were stained with Alizarin Red and featured some anatomical qualities which cleared the difference of the muscular and skeletal fabric for each fish. Since clear Histologic differences appeared in these two species, it was intended from this study the possibility of adopting a diagnosis between local fish species by staining bones and tissues.

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