Table of content

AL Rafdain Engineering Journal

مجلة هندسة الرافدين

ISSN: 18130526
Publisher: Mosul University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

Al Rafidain Engineering Journal
Abstract

The first issue of Al Rafidain Engineering Journal published in 1993 by the college of engineering – University of Mosul. The journal is publishing at a rate of six issues in the year (Bi-Monthly).
The journal publishes the referred original and valuable engineering research papers.
Al Rafidain engineering journal includes the following titles:

• Architectural Engineering
• Civil Engineering
• Computer Engineering
• Electrical Engineering
• Environmental Engineering
• Mechanical Engineering
• Megatronic Engineering
• Water Resources Engineering
The aim of publishing the journal is to develop the knowledge in the fields of applied engineering science.

• irrigation and drainage engineering
• Computer Engineering
Target domain and
Rivers Engineering magazine aims to develop knowledge in the field of engineering and science related to it. Should contribute to the article submitted for publication in the development of engineering sciences in various fields will be considered in the dissemination of innovative and distinctive articles in these areas. Articles which are referred to the magazine for the purpose of evaluating the arbitrators with the reputation and extensive experience in the field of jurisdiction has been accepted for publication or apologize. And will be re-papers not accepted for publication to their owners.

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Contact info

ealrafidain@yahoo.com

Table of content: 2005 volume:13 issue:4

Article
Neural network Feature Extraction for the Tasks of Visual Recognition
اقتباس الخواص باستخدام الشبكات العصبية لاغراض التمييز الصوري

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Abstract

Abstract In this Paper, a neural network image recognition system is used. The Neocognitron[8] in that system is used as feature extractor, then the feature are classified by using a multilayered feedforward network to generate recognition codes. Many neural learning algorithms are used to extract the feature, then comparison among them is presented. Finally a comparison between most active algorithms among them with respect to the whole performance of the of the designed system is presented. The biases used in MBCL (Modified Bias Competitive Learning) played an important role to improve the performance of competitive learning algorithms. Using SOFM (Self Organizing Feature Map) to extract features gave better recognition rate than MBCL and other algorithms. Keywords: Feature extraction, Competitive learning, Image recognition, Neocognitron


Article
THE EFFECT OF THE HEIGHT AND SPEED OF THE AIRPLANE CARRYING THE FOCUSED SYNTHETIC APERTURE RADAR ON THE AZIMUTH RESOLUTION
تأثير ارتفاع وسرعة الطائرة الحاملة لرادار الفتحة المصطنعة المبأر علىالدقة في الاتجاه السمتي

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Abstract

Abstract: Airborne imaging radar systems are known by their ability to produce high resolution images of ground targets using microwave region of electromagnetic waves. There are many military and civilian applications of imaging radar systems. The high resolution images achieved by transmitting a number of electromagnetic pulses to the earth surface then integrating them coherently at the receiver. A study have been achieved to show the effect of changing speed or height or both of the airplane carrying the focused synthetic aperture radar upon the azimuth resolution. The simulation results showed that increasing the speed or decreasing the height of the airplane will improve the azimuth resolution, and it can be noted for practical parameters that decreasing the speed and the height of the airplane leads to degraded azimuth resolution. The results of azimuth resolution obtained from simulations and those from theoretical calculations are nearly identical for targets of point reflecto

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Article
Neural network Feature Extraction for the Tasks of Visual Recognition
اقتباس الخواص باستخدام الشبكات العصبية لاغراض التمييز الصوري

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Abstract

Abstract In this Paper, a neural network image recognition system is used. The Neocognitron[8] in that system is used as feature extractor, then the feature are classified by using a multilayered feedforward network to generate recognition codes. Many neural learning algorithms are used to extract the feature, then comparison among them is presented. Finally a comparison between most active algorithms among them with respect to the whole performance of the of the designed system is presented. The biases used in MBCL (Modified Bias Competitive Learning) played an important role to improve the performance of competitive learning algorithms. Using SOFM (Self Organizing Feature Map) to extract features gave better recognition rate than MBCL and other algorithm


Article
Analysis and Design of a Novell VPN Switch
تحليل و تصميم مفتاح جديد للشبكة الافتراضية الخصوصية

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Abstract

Abstract Security problems take an important part of computer network study in which several techniques were developed for this purpose. Virtual Private Networks (VPNs) are considered as an active form for providing secure networks. The key feature of VPNs is that they are able to use public networks like the Internet rather than rely on expensive private lines. The aim of this paper is to design a VPN switch with the help of simulink software provided by MATLAB 6.5. The VPN switch is a single hardware device, it has the ability to support firewall, encryption, authentication, and data integrity for secure tunneling across managed IP networks and Internet. Introducing scrambling code within a VPN switch for encryption is something new. The basic advantage of this method is to eliminate long headers, which are usually dedicated for authentication and encapsulation in IPSec. Therefore an increase in the bandwidth efficiency of the channel is expected. Larger values of spreading factor show better probability of error and data integrity in spite of the decrement in the bandwidth of the channel in some cases.

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Article
A Two –Dimensional numerical Study of the effect of variable heat transfer coefficient on the performance of annular fins
دراسة عددية ثنائية البعد لتأثير تغير معامل انتقال الحرارة

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Abstract

Abstract This work involves a numerical two-dimensional study on the effect of the variation in heat transfer coefficient on the performance of annular fins. The object was to study the effect of varying the heat transfer coefficient on the fin efficiency. , Fin effectiveness, optimum length and the heat flow for fins of different cross-section, namely, constant thickness, and trapezoidal assuming a two dimensional flow inside the fin (radial and axial). The results were obtained through setting up the governing equations and solving them by a finite difference technique employing the method of grid generation and coordinate transformation with the aid of the Gauss-Siedel method. A power relationship was used to describe the variation of the heat transfer coefficient as a function of the fin length. It was found that the variation in heat transfer coefficient reduces the fin efficiency, effectiveness, optimum length and the temperature gradient at the root of the fin and consequently the amount of heat transfer. Further more this variation led to an increase in the volume required to dissipate a known quantity of heat as compared to the constant coefficient case It was also found that heat dissipation increased with the increase in fin length to a certain limit and then begins to drop.

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Article
THE EFFECT OF STEEL FIBERS ON THE MECHANICAL PROPERTIES OF HIGH PERFORMANCE CONCRETE
تأثير الألياف الحديدية على الخواص الميكانيكية للخرسانة العالية الأداء

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Abstract

ABSTRACT The present investigation considers the effect of steel fibers content and the combined effect of rice husk ash (RHA) and high range water reducing agent (HRWRA) on the mechanical properties of the produced matrix. The experimental results showed the using steel fibers in High-performance concrete led to a considerable improvement in mechanical properties of concrete. The results exhibited that the addition of steel fibers to high performance concrete up to 1% with 6% (HRWRA) and 8% (RHA) as a partial replacement by weight of cement, increases the compressive strength significantly. Also, the results showed that the addition of 1.5% steel fibers with 6% (HRWRA) and 8% (RHA) increases the splitting and flexural strengths significant. At 28 days, the compressive, splitting and flexural strengths were increased to 11.57%, 63.86%, and 32.93% more than High performance concrete without steel fibers, respectively. Key words: Concrete, Mechanical properties, High performance concrete, Strength, Admixtures


Article
EFFECT OF CYCLIC HEATING ON REINFORCED CONCRETE THICK PLATES
تأثير التسخين المتناوب على الصفائح الخرسانية المسلحة السميكة

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Abstract

to study the effect of cyclic heating and cooling on the nonlinear analysis of the reinforced concrete plate at different load conditions before and after cracking up to failure, and it`s effect on cracking and crushing of concrete and yielding of steel.Also to calculate the stresses and strains due to the applied load under the effect of cyclic heating and cooling . The study also present the mathematical mode for the behavior of the reinforced concrete plate under cyclic heating with different variables , such as temperatures , duration of heating, and number of cyclic heating ,The relation between load and deflection .is presented . Ressiner`s theory has been used to represent the behavior of thick plate . The Finite Difference method and Dynamic Relaxation have been used in the solution of the differential equations ..

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Article
Computer Simulation of the Performance of Industrial Gas Turbines with Application to Mosul Power Station
نمذجة أداء التوربينات الغازية الصناعية وتطبيقها على محطة التوليد

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Abstract

Abstract:- A thermodynamic simulation of the power generation gas turbine of the Mosul gas turbine power station was carried out, and its performance was observed. The simulation included detailed modeling of the compressor, the combustion chamber and the turbine based on the physics as well as the common practice in the field. Comparison of the simulation code results with the field collected data indicated agreement to within 2% of the compared parameters. The developed code then used to study the effect of varying the ambient temperature on the performance of the system. The results showed a decrease of up to 21% in the power output when the ambient temperature increases from its ISO value of 15 °C to 45 °C. Comparison between running the system under constant turbine inlet temperature and constant turbine power output were also conducted.

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Article
LABORATORY STUDY OF SCOUR IN LONG CONTRACTIONS
دراسة مختبرية للنحر في التخصرات الطويلة

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Abstract

In this investigation, scour in long contractions phenomenon was studied experimentally. For this purpose, forty laboratory experiments were carried out in a laboratory channel .Two different river sand sizes of 0.653 mm, 1.040 mm were used to conduct the experiments with standard deviations of 2.151 and 3.474 respectively. Three different ratios of contraction (B1/B2 =4,3 and 2) and three different angles of contraction (θ=10,15 and 20 degrees) were tested. For each case, the discharge was changed four times from 10.4 Liter/sec to 47.6 Liter/sec. Data analysis showed that depth of scour (ds) depends mainly on contraction ratio (B1/B2), densimetric particle Froude number (Frο) and geometric standard deviation (σg). Results of this study showed that there is a strong linear direct relation between the ratio of the contraction channel width and the depth of scour. Also a direct relationship was found to describe the effect of discharge on depth of scour. The results showed that there is no effect of contraction angle on the scour depth in long contractions. Also, an empirical non-dimensional relationship was obtained to determine depth ratio (Y2/Y1) in long contraction with correlation coefficient (R2) = 0.9343. The results of the present investigation were compared with those of other investigators showing a good agreement among them

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Article
Rhythmic Structure in Islamic Architecture
البنية الإيقاعية في العمارة الإسلامية

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Abstract

Abstract The study defines the research problem as a reconsideration or reformulation of a scientific approach to study of the dimensions of rhythm in Islamic Architecture, depending on rhythmic polyphonic and harmonic relations in Islamic architecture, as well as on rhythmic in Arabic poetry and music. To fulfill such as objective a scale for rhythmic dimension is being laid down. The hypothesis postulates that the aesthetic taste constituting the dimensions of rhythm in Islamic architecture is itself the force behind Arabic poetry and music. So that the characteristics of rhythm in Arabic poetry and music are defined and clarified going back to their roots as they were founded by Al- Khalil Bin Ahmad, Al-Farabi, Ekhwan Al-Safa and Al-Armani. A graphic model for musical and poetic rhythm is devised so as to project the distinctive features descriptive of the Islamic character and how they may apply to Islamic architecture in eclectic samples. Periods, beats and paces between music and poetry on the hand and their architectural counterparts on the others are being rigorously compared. The results project similarity and continuity of the expressive aspects in Islamic architecture and Arabic music and poetry for both reflect the slow, monotonous and infinite nature of the Muslim mind. The groupings, spaces and modulation in both arts are almost identical. In both arts the shape and the rhythm are but reflections and an embodiment of the same cultural tempo and spirit… infinite, colorless and monotonous.

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