doi:10.21123/bsj.2014.11.2.742-747

Details

Publication Date

Sun Jun 01 2014

Journal Name

Baghdad Science Journal

Volume

11

Issue Number

2

DOI

10.21123/bsj.2014.11.2.742-747

Choose Citation Style

Statistics

View publication

1

Abstract Views

2.06K

Galley Views

217

Statistics

Simulation Study on Optically Designed Refractive Beam Expander for Nd: YAG Laser Harmonics for 7 Km Detection Range

Beam Expander

Laser

Spot Size

Expansion Ratio

Galilean

Keplerian.

Hisham A.

Assma A.

...Show More Authors

The simulation study has been conducted for the harmonics of Nd: YAG laser, namely the second harmonic generation SHG, the third harmonic generation THG, and the fourth harmonic generation FHG. Determination of beam expander's expansion ratio for specific wavelength and given detection range is the key in beam expander design for determining minimum laser spot size at the target. Knowing optimum expansion ratio decreases receiving unit dimensions and increases its performance efficiency. Simulation of the above mentioned parameters is conducted for the two types of refractive beam expander, Keplerian and Galilean. Ideal refractive indices for the lenses are chosen adequately for Nd: YAG laser harmonics wavelengths, so that increasing transmission of laser beam, consequently the received power to the detector for practical convenience.

View Publication Preview PDF

Quick Preview PDF

Publication Date

Tue Nov 30 2021

Journal Name

Iraqi Journal Of Science

Synthesis and Characterization of a Nano (CdO)0.94:(In2O3) 0.06 / Si gas Sensor

Gas nanosensors

(CdO)0.94:(In2O3)0.06 thin film

morphological properties

electrical property and pulsed laser deposition technique

M. F. A.

H. A.

...Show More Authors

In this work, a (CdO)_0.94:(In₂O₃)_0.06film was developed on a glass substrate using Q- switching pulse laser beam (Nd:YAG; wavelength 1064 nm). The quantitative elemental analysis of the (CdO)_0.94:(In₂O₃)_0.06thin film was achieved using energy dispersive X- ray diffraction (EDX). The topological and morphological properties of the deposited thin film were investigated using atomic force microscope (AFM) and field emission scan electron microscopy (FESEM). The I-V characteristic and Hall effect of (CdO)_0.94:(In₂O₃)_0.06 thin films were used to study the electrical properties. The gas sensor prope

View Publication Preview PDF

Publication Date

Wed May 17 2017

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

Image Compression Using Proposed Enhanced Run Length Encoding Algorithm

: Compression

RLE

Run length encoding

GIF

TIFF

PNG

JPEG

BMP

BMP header

BMP file

Compression ratio

Lossless

Lossy

True color.

A. H.

S. Sh.

R. J.

...Show More Authors

In this paper, we will present proposed enhance process of image compression by using RLE algorithm. This proposed yield to decrease the size of compressing image, but the original method used primarily for compressing a binary images [1].Which will yield increasing the size of an original image mostly when used for color images. The test of an enhanced algorithm is performed on sample consists of ten BMP 24-bit true color images, building an application by using visual basic 6.0 to show the size after and before compression process and computing the compression ratio for RLE and for the enhanced RLE algorithm

View Publication Preview PDF

(7)

Publication Date

Mon Sep 16 2019

Journal Name

Ibn Al-haitham Journal For Pure And Applied Sciences

New Techniques of Watermark Images using Bit Plane Slicing and Cubic-spline Interpolation

Watermark

Cubic-spline Interpolation (CSI)

Bit Plane Slicing (BPS)

Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR).

Huda

...Show More Authors

A watermark is a pattern or image defined in a paper that seems as different shades of light/darkness when viewed by the transmitted light which used for improving the robustness and security. There are many ways to work Watermark, including the addition of an image or text to the original image, but in this paper was proposed another type of watermark is add curves, line or forms have been drawn by interpolation, which produces watermark difficult to falsify and manipulate it. Our work suggests new techniques of watermark images which is embedding Cubic-spline interpolation inside the image using Bit Plane Slicing. The Peak to Signal Noise Ratio (PSNR) and Mean Square Error (MSE) value is calculated so that the quality of the original i

View Publication Preview PDF

Publication Date

Wed May 10 2023

Journal Name

Journal Of Engineering

SDPLL-Based Frequency Estimation of a Sinusoid in Colored Noise

Sinusoidal digital phase-locked loop (SDPLL)

Cramer-Rao bound (CRB)

colored noise

frequency error variance

signal-to-noise ratio (SNR).

Nuha Abdul Sahib

Zainab Hassan

...Show More Authors

The problem of frequency estimation of a single sinusoid observed in colored noise is addressed. Our estimator is based on the operation of the sinusoidal digital phase-locked loop (SDPLL) which carries the frequency information in its phase error after the noisy sinusoid has been acquired by the SDPLL. We show by computer simulations that this frequency estimator beats the Cramer-Rao bound (CRB) on the frequency error variance for moderate and high SNRs when the colored noise has a general low-pass filtered (LPF) characteristic, thereby outperforming, in terms of frequency error variance, several existing techniques some of which are, in addition, computationally demanding. Moreover, the present approach generalizes on existing work tha

View Publication Preview PDF

Publication Date

Sun Jul 09 2023

Journal Name

Journal Of Engineering

PAPR Reduction of OFDM Signals Using Clipping and Coding

OFDM (orthogonal frequency division multiplexing)

PAPR (peak to average power ratio)

clipping

QPSK (quadrature phase shift keying) modulation

QAM (quadrature amplitude)

channel coding.

Mohammed Kasim

...Show More Authors

The problem of the high peak to average ratio (PAPR) in OFDM signals is investigated with a brief presentation of the various methods used to reduce the PAPR with special attention to the clipping method. An alternative approach of clipping is presented, where the clipping is performed right after the IFFT stage unlike the conventional clipping that is performed in the power amplifier stage, which causes undesirable out of signal band spectral growth. In the proposed method, there is clipping of samples not clipping of wave, therefore, the spectral distortion is avoided. Coding is required to correct the errors introduced by the clipping and the overall system is tested for two types of modulations, the QPSK as a constant amplitude modul

View Publication Preview PDF

Publication Date

Fri Mar 01 2019

Journal Name

Applied Acoustics

Theoretical model of absorption coefficient of an inhomogeneous MPP absorber with multi-cavity depths

Micro-perforated panel (MPP) absorber has been known as an alternative absorber to classical porous material given its facile installation

long durability

environmental friendliness and attractive appearance. Extensive studies of MPP absorber proposing the improvement of its absorption frequency bandwidth have been published. This study presents a MPP absorber introduced with inhomogeneous perforations and with multi-cavity depths. The MPP is divided into two sub-area

where each area has different hole diameter

perforation ratio and a separated backed cavity depth. The acoustic impedance is modelled using electrical equivalent circuit and the absorption coefficient is calculated under normal-incidence of sound. It is found that the inhomogeneous MPP can have good bandwidth of absorption by designing the sub-MPP of smaller perforation ratio with large hole diameter and the one having the larger perforation ratio with smaller hole diameter. The absorption bandwidth can be conveniently controlled by adjusting the cavity depth of each sub-MPP. The results from the experimental work show good agreement with the theoretical model.

Ali Ibrahim

Azma

Roszaidi

Iwan

Al-Ameri

...Show More Authors

View Publication

(72)

(62)

Publication Date

Sat Oct 01 2016

Journal Name

Journal Of Theoretical And Applied Information Technology

Factors affecting global virtual teams’ performance in software projects

Today the trend is to perform software development work via distributed geographical area among team

individual or even as an organization. However

due to the global market and international presence of many companies

there is a need to implement a global virtual teams. The global virtual team members are gradually engaged in globalized business environments across space

time and organizational boundaries via information and communication technologies. A global virtual team relies on communication

collaboration

and information exchange are the most important criteria in global virtual teams’ operations. The purpose of this paper is to answer two research questions. The first research question is to identify the factors affecting global virtual teams’ performance. A systematic literature review was conducted to answer the first research question. The second research question is on what the rank of the factor affecting the global virtual teams’ performance according to their level of effect on global virtual teams’ performance. Online survey was conducted within 103 developers and IT managers from eight IT companies to answer the second research question. The Statistical Package for Social Science (SPSS 22) was used to analyze the collected data. In this study

we investigated factors that affect global virtual teams’ performance

factors considered include cultural differences

language problems

time-zone differences

team size

technical problems

lack of trust

lack of sufficient training

and ICT problems. Also the findings indicated that lack of sufficient training is the highest level of effect on global virtual teams’ performance. On the other hand

Ali Yahya Gheni

...Show More Authors

(23)

Publication Date

Tue Mar 01 2022

Journal Name

Iraqi Journal Of Agricultural Sciences

CORRELATION OF TMPRSS2-ERG GENE FUSION STATUS WITH CLINICOPATHOLOGICAL CHARACTERISTICS IN PROSTATE CANCER OF IRAQI PATIENTS

The aim of this study was to establish the existence and interaction of TMPRSS2 – ERG gene fusion status with clinicopathological features of prostate cancer patients. This research consisted of 123 embedded formalin-fixed tissues obtained from the prostate tumor patients. The above gene fusion is detected through the technique of fluorescent in situ hybridization (FISH) by means of a triple color probe. Seven samples have not been scored due to technical difficulties and 46 patients have fusion (39.6%)

while the remaining (70) have not been seen with fusion. Of the 46 fusion-positive

17 (36%) were caused by ERG-translocation

of the other 29 (63%) were caused by the interstitial segment deletion between the two genes due to their sequential position. In order to find a substantial correlation between 116 patients (fusion took place in 46 and non-fusion in 70) with clinicopathological features

the following findings were calculated: Our findings recorded non-significant correlation at age

BMI and tumor size at which (P-value >0.05).While results showed significant association with: pathological T stage (P value = 0.011)

Gleason score (P value = 0.002)

perineural invasion (P value = 0.047) and PSA (P value = 0.033). The clinicopathological features which had a considerable correlation with fusion status are very important as they aid the doctors in prognosis and treatment of such tumor.

Ammar

Maha

...Show More Authors

1 2 3 4 ... 1648 1649 1650 1651