Preferred Language
Articles
/
joe-1095
Pilot Based Channel Estimation and Synchronization in OFDM System
...Show More Authors

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.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Dec 01 2018
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Proposed Introduction to Activate the Role of Accounting System for Political Parties in Iraq
...Show More Authors

     Purpose - The study aimed at evaluating the accounting system of the Iraqi political parties, which is applied according to legislative texts, and then the ability to provide accounting information to evaluate the strategic performance and control of the party's operational and financial performance.
Findings- The research found that the unified accounting system applied to political parties does not provide relevance informations to judge the performance of the political party, the researcher a proposal for an accounting system that provides the necessary information to measure and monitor the performance of Iraqi political parties can be presented. The

... Show More
View Publication
Crossref
Publication Date
Tue Mar 01 2022
Journal Name
Journal Of Engineering
A Impact of High Voltage Direct Current Link on Transmission Line in Kurdistan Power System
...Show More Authors

Kurdistan power system is expanded along years ago. The electrical power is transmitted through long transmission lines. The main problem of transmission lines is active and reactive power losses. It is important to solve this issue, unless, the most of electrical energy will lost over transmission system. In this study, High Voltage Direct Current links/bipolar connection were connected in a power system to reduce the power losses. The 132kV, 50 Hz, 36 buses Kurdistan power system is used as a study case. The load flow analysis was implemented by using ETAP.16 program in which Newton-Raphson method for three cases. The results show that the losses are reduced after inserted HVDC links.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Apr 01 2017
Journal Name
Applied Energy
Melting enhancement in triplex-tube latent heat energy storage system using nanoparticles-metal foam combination
...Show More Authors

View Publication
Scopus (280)
Crossref (274)
Scopus Clarivate Crossref
Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Role of Internal Contrl in Electronic Accounting Information System: Applied Study in Spacimen from Kurdistan Regin Iraq
...Show More Authors

Internal control is system,defined and implemented under its responsibility , which aims to ensure that; laws and regulations are complied with; the instructions and directional guidelines fixed by Executive Management or the Management Borad are applied; the company internal processes are functioning correctlly , particularly those implicating the security of its assets; Financial Information is reliable; and generally contributes to the control over its activities , to the efficiency of its operation and to the efficient utilisation of its Resources. By helping to anticipate and control the risks involved in not meeting the objectives the company has set for itself, the internal control system plays akey role in conducting & monito

... Show More
View Publication Preview PDF
Publication Date
Fri Dec 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Estimation of secondary compounds content of some citrus leaves and their relationship by dietary preference for yellow scale insect Aonidiella. Orientalis (Hemiptera: Diaspididae)
...Show More Authors
Abstract<p>The yellow scale insect <italic>Aonidiella orientalis</italic> is an important pest of citrus trees as it absorbs sap from leaves and fruits, causing leaves to turn yellow and deform fruits and drop them. The results of study showed nutritional preference of the insect over some of studied citrus species, as sour orange was the most preferred, followed by lemon and grapefruit, mandarin and oranges were least preferred, with a rate of 22.3, 13.3, 11.7, 10.8, 3.9, and insect / 2 inch<sup>2</sup>, respectively. while results showed a difference in the content of citrus leaves from the secondary compounds, with highest concentration of phenols and total flavonoids in o</p> ... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Journal Of Economics And Administrative Sciences
Using Iterative Reweighting Algorithm and Genetic Algorithm to Calculate The Estimation of The Parameters Of The Maximum Likelihood of The Skew Normal Distribution
...Show More Authors

Excessive skewness which occurs sometimes in the data is represented as an obstacle against normal distribution. So, recent studies have witnessed activity in studying the skew-normal distribution (SND) that matches the skewness data which is regarded as a special case of the normal distribution with additional skewness parameter (α), which gives more flexibility to the normal distribution. When estimating the parameters of (SND), we face the problem of the non-linear equation and by using the method of Maximum Likelihood estimation (ML) their solutions will be inaccurate and unreliable. To solve this problem, two methods can be used that are: the genetic algorithm (GA) and the iterative reweighting algorithm (IR) based on the M

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
Obstacles to Administrative Creativity of Female Leaders in Secondary Schools (Curriculum System) in the Northern Border Region in Saudia Arabia
...Show More Authors

The study aimed to reveal the obstacles of administrative creativity among the leaders of secondary schools (the curriculum system) in the northern border region, which relate to the obstacles (organizational, motivational, and psychological). In addition, to identify the most important statistical differences between the responses of the members of the study sample, which attribute to the variables (educational qualification, year’s Administrative expertise). To achieve the goal of the study, the researcher used the descriptive analytical approach, and to verify the validity of the tool, it has presented to several referees and faculty members in the educational field. The validity of the internal consistency was also calculated for t

... Show More
View Publication Preview PDF
Publication Date
Wed Sep 16 2020
Journal Name
International Journal Of Dentistry And Oral Science
Attitude and Knowledge of Orthodontics among General Dentists and Non-Orthodontic Specialists: A Questionnaire Based Survey
...Show More Authors

Aim: This study aimed to assessing orthodontic knowledge and attitude among general dentists and non-orthodontic specialists. Background: Early detection of orthodontic disorders is essentialin motivating patients to intervene prior to long term complications when the disorders are not recongised. Methods: A questionnaire was distributed amongst dentistsother than orthodontists. This questionnaire consisted of three sections. The first one aimed to collect demographic, educational level and practice type information. Further two sections consisted of closed-end questions designed to evaluateknowledge and attitude of orthodontics. Results: A total of 313 responses to the survey were submitted. No significant correlation was observed, e

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Sat Aug 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Comparison of Single and Group Jet Grout Columns Settlement Based on Field Test and Theoretical Methods
...Show More Authors
Abstract<p>The settlement evaluation for the jet grouted columns (JGC) in soft soils is a problematic matter, because it is influenced by the number of aspects such as soil type, effect mixture between soil and grouting materials, nozzle energy, jet grouting, water flow rate, rotation and lifting speed. Most methods of design the jet-grouting column based on experience. In this study, a prototype single and group jet grouting models (single, 1*2, and 2*2) with the total length and diameter were (2000 and 150 mm) respectively and clear spacing (3D) has been constructed in soft clay and subjected to vertical axial loads. Furthermore, different theoretical methods have been used for the estimation </p> ... Show More
View Publication
Crossref
Publication Date
Thu Jun 20 2019
Journal Name
Baghdad Science Journal
An Optimised Method for Fetching and Transforming Survey Data based on SQL and R Programming Language
...Show More Authors

The development of information systems in recent years has contributed to various methods of gathering information to evaluate IS performance. The most common approach used to collect information is called the survey system. This method, however, suffers one major drawback. The decision makers consume considerable time to transform data from survey sheets to analytical programs. As such, this paper proposes a method called ‘survey algorithm based on R programming language’ or SABR, for data transformation from the survey sheets inside R environments by treating the arrangement of data as a relational format. R and Relational data format provide excellent opportunity to manage and analyse the accumulated data. Moreover, a survey syste

... Show More
View Publication Preview PDF
Crossref (1)
Clarivate Crossref