Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 16, Issue 3

Volume 16, Issue 3, Summer and Autumn 2008, Page 1-155


Online Tracking Control System For Robot Manipulator Using Adaptive Fuzzy Wavelet Network

Yhya R. Kuraz; Waleed Ameen Mahmoud Al-Jawher

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 1-10
DOI: 10.33899/rengj.2008.44606

Abstract
It is well known that Wavelet Networks (WN) are powerful tools for handling problems of large dimensions. The integration of Wavelet Network and Fuzzy Logic (FL) enable a tool condition monitoring system to have a high monitoring success rate and fast training feed over a wide range of cutting conditions in drilling applications. To overcome offline learning and to perform efficient tracking behavior, an Auto Tuning Adaptive Fuzzy Wavelet Network (ATAFWN) controller is proposed. It was shown that such structure don’t need offline learning to govern the system in stable regions. It can be handle also a wide range of parameter changes in comparison with the conventional controller as well as such controller is simple to configure since it doesn’t need a process model and can be easily adapted to the existing controller and plants.

Keywords: online controller, fuzzy logic, wavelet network, fuzzy wavelet network.

Freehand Drawing Techniques Its Role in Architectural Design

Dhuha Abdul Gani Abdul Aziz

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 1-13
DOI: 10.33899/rengj.2008.44685

The research deals with freehand sketching and diagramming techniques, explaining its important role as a design tool in early stages of architectural design process, as a tool of design thinking, a tool of communication, and a tool of interpretation and reasoning. In relation to its role as a tool of design thinking varying between conceptual and perceptual thinking, it is active in the initial stages of the design process, which are the exploration, extraction and development stages. It plays a prominent role in the exploration phase through stimulating and expanding designer thinking as an assistant tool in analytical thinking, retrospective thinking and speculative thinking. Its role in extraction phase as synthesis tool leads to investigation of alternatives, and as evaluation tool to test and verify the design solutions. In development phase, it helps the designer thought to reach the re-interpretation and unexpected discoveries. The research highlights freehand drawing techniques role as a communication tool between architect and himself, and architect and his group or architect and public. In addition to its role as interpretation and reasoning tool to reveal the designer intentions explaining the design content or design process.

Development and Evaluation of two Memory Architectures for the Hardware Version of CNN Face Recognizer

Shefa A. Dawwd; Basil Sh. Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 11-24
DOI: 10.33899/rengj.2008.44612

Abstract
The design of the proposed Convolutional Neural Network (CNN) architecture for face image recognition takes the constraints on the bandwidth of the communications between memory and processor into the account. The coarse grained parallelism which performed in the bottom layer node's calculations is reduced in consequent manner until the calculation of one simple node in the upper layer is achieved sequentially. Two methods of segmentation are used to buffer the image data required for these parallel to sequential calculations from the image RAM to multi-port RAMs. A comparison between these two methods with respect to the whole number of RAM access required to generate the system recognition code is performed. A speedup of 44 is achieved when the hardware system is implemented with the using of the 1st method of segmentation as compared to a Pentium 4, 2.4 GHz sequential computer software implementation. While a speedup of 88 is achieved when the same hardware system is implemented but with the using of the 2nd segmentation method, compared to the same mentioned sequential computer.
Keywords: convolution neural networks, parallel processing, memory architecture.

A Mathematical Model for Azizya Evaporating Pond Operation Using SIMULINK Techniques

Kamel A. Al-Mohseen

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 14-24
DOI: 10.33899/rengj.2008.44692

The present research is to study the water balance for Aziziya Evaporating Pond (AEP) project by building a simulation model to evaluate its hydraulic performance under different scenarios of operation and to estimate the expected discharge of its spillway, which gives the design discharge for the main drain of AEP.
The study revealed that the operation process of the pond is a balance among inflow , storage and released water. Furthermore, when the steady state condition is achieved, various operating scenarios lead to the same result, therefore, the decision maker must take the appropriate decision for implementation.
The study also showed that the maximum expected discharge during any month of the year is when the crest elevation of the spillway is (21.5) m , after reaching the steady state condition during the third year of operation , is about (16) m3 /sec. Furthermore, changing the elevation of the crest to (23.3 m) is associated with a zero discharge over the spillway.
The research work revealed the remarkable capability of SIMULINK techniques used to built the simulation model for AEP and the flexibility in accepting any change in the model components in addition to its high speed of execution.
Keywords: Simulation, Reservoir Operation, Simulink

A Simulation Study of Tunneled Voice over Internet Protocol System

A. I. A. Jabbar; D. M. Ali

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 25-38
DOI: 10.33899/rengj.2008.44619

In this paper, the effects of real time traffic on non real time traffic are explained for conventional VoIP system. Also two types of Quality of Service models are applied; the End to End delay, the throughput, and the number of dropped packet are the main parameters used to evaluate the network performance. A new technique is proposed to solve the above problems. This technique is based on the tunneling process to carry the real time traffic. Some analysis is performed to expect the maximum call number served by a network. To overcome the overhead problem due the tunnel, two parameters are included; the first one is the number of real time packets tunneled in each frame, and the second one is the voice frame size. The analysis and the simulation show that as the number of the tunneled packet becomes larger, the maximum call number approaches to the non tunnel situation. On other hand, as the frame size becomes larger, the maximum call number exceeds the non tunneled situation. Of course, the maximum number of tunneled packets and the frame size affect the End to End delay which is controlled by the type of CODEC being used. A compromised value can be found to achieve the better network response. OPNET MODELER is the simulating software being used together with a dedicated program for performing some calculations related to network performance.
Key Words :VOIP, Accelerator,QoS,weighted Fair Queuing, Priority Queuing, Bandwidth efficiency, Header Compression, Tunneling, OPNET Modeler.

Improve Watermark Security Via Wavelet Transfrom And Cdma Techniques

Yhya. R. Kuraz; Modar A.H

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 39-49
DOI: 10.33899/rengj.2008.44625

With the growth of multimedia systems in distributed environments, the research of multimedia security as well as multimedia copyright protection becomes an important issue. As a potential and effective way to solve this problem, digital watermarking becomes a very active research area of signal and information processing. Many watermark algorithms have been proposed to address this issue of ownership identification. Discrete Cosine Transform (DCT) based spread-spectrum watermarking is one of the famous techniques. Another possible domain for watermark embedding is the wavelet domain. One of the many advantages over the Discrete Wavelet Transform (DWT) is that more accurately model aspects of the human visual system (HVS).
In this paper a proposed algorithm is defined based on the combination between the benefits provides by using wavelet domain and profits of Code division multiple access (CDMA) spread-spectrum technique. A pseudo-random sequence (key) that related to hidden message is embedded into the significant DWT coefficients of a cover image to produce a watermarked image. Experimental results demonstrate that the proposed algorithm is perceptual invisible and robust against many attacks such as lossy image compression and Additive White Gaussian Noise (AWGN).
Keywords: digital watermark, wavelet transform, CDMA technique.

The Effect of Lightning Impulse and Switching (over voltages) on stress distribution and space charge accumulation of HVDC XLPE cables at load and no load

Saad Samuel Sheet

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 50-61
DOI: 10.33899/rengj.2008.44628

Abstract
High voltage direct current (HVDC) power cables are usually exposed to high value of stresses from lightning impulses and switching surges (over voltages) at working under load and no load. In this research used a detail analysis for stresses behavior in the insulation of cable at over voltages and at both modes (load & no load). It also shows the effect of such over voltages (lightning impulse & switching surges) on space charge accumulation in the insulation of the cables at load and no load. The investigated cable is of rated voltage 33Kv insulated by cross-linked polyethylene (XLPE).Electrical field and space charge accumulation are carried out theoretically by the aids of computer programs. The results give an indication of the maximum stresses occurs in the cables insulation at over voltages for both modes (load and no load), and also give an induction of the space charge accumulation at over voltage and at load and no load. The results show that maximum stress occurred by lightning impulse is found much higher than that of switching operation for load and no load but the switching surge has longer period. Also the results show that the space charges accumulation at lightning impulse are more than at switching surges for both modes (load & on load). Both main results (Electrical stresses and space charge accumulation) are found depends on the polarity of the over voltages.


Keywords: HVDC stress distribution at load, XLPE HVDC at load & no load

Hardware Implementation of Backpropagation Neural Networks on Field programmable Gate Array (FPGA)

Rafid Ahmed Khalil

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 62-70
DOI: 10.33899/rengj.2008.44649

In this paper, a design method of neural networks based on VHDL hardware description language, and FPGA implementation is proposed. A design of a general neuron for topologies using backpropagation algorithm is described. The sigmoid nonlinear activation function is also implemented. The neuron is then used in the design and implementation of a neural network using Xilinx Spartan-3e FPGA. The simulation results obtained with Xilinx ISE 8.2i software. The results are analyzed in terms of operating frequency and chip utilization.
Key words : Artificial, Neural , Network, Backprobagation, FPGA,VHDL.

Intelligent Systems based Selective Harmonic Elimination (SHE) for Single Phase Voltage SOURSE Inverter

Ahmed S. AL-soufy; Qais M. Alias; Basil M. Saied

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 71-81
DOI: 10.33899/rengj.2008.44650

Abstract

Pulse Width Modulation (PWM) inverters are of huge and great impact in many engineering disciplines. It plays a big role in the field of power electronics regarding voltage sources to vast amount of electronics equipments and machine controllers. The use of artificial intelligence in gate signals control in PWM voltage source inverter (VSI) is tackled, analyzed, and implemented in this paper. The PWM technique that investigated in this work is the Selective Harmonic Elimination (SHE). For this technique, the single phase H-bridge inverter is considered for the study. In the SHE based inverter, the fundamental voltage level and the harmonics selected for deletion are decided using a neural network ad fuzzy logics. For the SHE technique, the results of generating switching angle patterns, using the neural and the fuzzy model controllers, for driving H-bridge inverter, show almost exact resemblance, compared to those obtained using conventional controllers. Also the superiority at the intelligent models overcome the problem of delay time and have fast response in selecting and generating the PWM patterns required to regulate the inverter output voltage.
Keywords: H-bridge inverter, Pulse Width Modulation, Selective Harmonic Elimination, Intelligent Techniques.

Numerical Study Of Natural Convective Heat Transfer In An Inclined Square Porous Layer

Muyassar E. Ismaeel; Amir S. Dawood

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 81-95
DOI: 10.33899/rengj.2008.44651

Abstract

In this paper, steady two-dimensional natural convective heat transfer in an inclined square porous cavity with two parallel walls kept at constant different temperatures, while the other two parallel walls were well insulated, has been studied numerically. The governing equations have been solved using finite difference method. Results have been obtained for modified Rayleigh numbers between 0 and 300 and inclination angle between 0° (heated from below) and 90° (heated from side). The rate of heat transfer was found a strong function of modified Rayleigh number and inclination angle. The maximum heat transfer was occurred at about ( 50  ≤  ≤ 57  ) degrees of inclination.

Keywords:Natural Convective Heat Transfer, Porous Medium, Inclined Enclosure.

Relation Between Pre Straining Before Welding , Joint Design , And Microstructure In Welding Of (7020) Aluminium Alloy

Shawnim R. Jalal

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 96-103
DOI: 10.33899/rengj.2008.44653

Abstaract
In the utilization of aluminum alloys for structural applications , one difficulty to be overcome is the reduction of mechanical properties of welded joints as compared to the parent material, consequent upon the weaker strength of the welded metal (WM) and the distortion in the heat affected zone (HAZ) due to the welding thermal cycle . In the present investigation the tensile characteristics of joints welded plates of 7020 alloy under Arc welding at different pre strain before welding (5 ,10 , 20 ,30 %) and joint design (single and double V with angles equal to 70º,80º,90º) are investigated ,and the subsequent microstructure evolution after welding is assessed which improve the properties . This paper show that the improvement in mechanical properties (Yield and Tensile strength) carried out with 20% pre strain at a single V with angle equal to 90º compared with double V and reduced with increasing pre strain (30%) due to phase transformation of ή to the stable microstructure η (MgZn2). And changing joint design angles has little effect on mechanical properties improvement compared with joint design shape (single and double V ).
Keywords: 7020 Aluminum alloy; pre strain ; Arc welding ; joint design

Buckling Of Beams On Elastic Foundations

Mereen Hassan

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 104-122
DOI: 10.33899/rengj.2008.44659

Abstract
This study is an attempt to solve the general governing differential equation for buckling of beams resting on elastic foundation for different types of beams (pin ended, fixed ended and cantilever beams) taking into account the effect of soil sub-grade reaction value (K), axial load, lateral load and relative end settlement on the deflection and bending moment of the beams for prismatic and non–prismatic beams.
Approximate solutions are also presented using the extermization of the total potential energy equation (Rayleigh-Ritz method) using approximate shape functions for the deflection which satisfy the boundary conditions of the beam. The results show that one term series approximate solution gives acceptable results in comparison with the exact solution for practical case, the accuracy of the solution increases with increasing the number of terms up to 5 terms, beyond this limit the accuracy of the solution does not change. Buckling load increases linearly with increasing (K) while the deflection and the bending moment exponentially decrease with increasing (K).
Keywords: Bending moment, Buckling, Cantilever beam, Deflection, Fixed ended beam, Non-prismatic beam, Pin ended beam, Prismatic beam, Settlement and Soil sub-grade reaction.

The Effect Of Different Influencing Parameters On The Design Of Concrete Mixes

B.M. Jassim; N. H. Al-jubory; Khalid A. A.Zakaria

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 123-131
DOI: 10.33899/rengj.2008.44665

Abstract
The aim of this research work is to judge whether the inclusion of different influencing parameters on some concrete characteristics have been justified and materialized in four methods of mix design namely ACI , D.O.E , Murdock & the Basic, These were used to design mixes of a given workability ( a slump of 75- 90 mm ) at four strength levels 20 , 30 ,35 ,&40 MPa , the results indicated that at a random strength of 30 MPa :
1. CI method: highest cement content, lowest w/c ratio, lowest gravel content.
2. D.O.E method: second highest cement content, second richest mix, second lowest w/c ratio.
3. Murdock method: highest sand content, lowest water content, low cement content.
4. Basic method: lowest cement content, lowest sand content, highest gravel content, and leanest mix.
Keywords: Mix design, Influencing parameters, ACI, D.O.E, Murdock, and Basic.

Using of GPS and Leveling Techniques for Determining the Orthometric Heights inside Mosul University

Nashwan Kamal-aldeen; Sabah Hussein Ali

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 132-142
DOI: 10.33899/rengj.2008.44669

Abstract
It is possible to determine heights of selective locations through terrestrial means by tying these locations to the sea level. Practical heights in geodesy, known as orthometric heights are referred to the geoid, which is approximated by the mean sea level (MSL).
In the present study, A GPS and conventional leveling techniques were used to establish a network of (15) control points distributed inside Mosul University Campus, to be as a bench marks for the surveying applications which are very important and necessary for the civil engineering projects and the geophysical survey. The obtained results show that, there is an average variation between the orthometric heights measured by leveling instrument and the ellipsoidal heights measured by GPS, referred to as geoid undulation. ArcGIS9.1 software was applied in the study for the georeferencing process of the GPS measured dataset.

Keywords: GPS, orthometric height, mean sea level

Scour Downstream an Ogee Spillway

Khalil I. Othman

AL-Rafdain Engineering Journal (AREJ), Volume 16, Issue 3, Pages 143-155
DOI: 10.33899/rengj.2008.44680

Abstract
An experimental investigation on the problem of local scour downstream Ogee spillway is presented here by using two types of noncohesive bed material. The paper briefly explains the effect of hydraulic conditions of flow and sediment characteristics on depth and the extent of scour. The obtained results show that the depth and extent of scour affect greatly by the rate of the discharge and the depth of tail water. The size and shape of bed material particles plays an important role in characteristics of the occurred scour. The experimental data was used to develop two empirical relations to predict the depth and the extent of the scour downstream the Ogee spillway.

Keywords: Scour, Ogee type Spillway, Hydraulics