Print ISSN: 1814-6120

Online ISSN: 2311-8385

Volume 10, Issue 1

Volume 10, Issue 1, Spring 2010, Page 1-168


Fuzzy Logic Based Speed Control of a Five-Phase Series-connected Two-Motor Drive System Fed from SVPWM VSI

Hashim Thejel; Rabee; Haroutuon A. Hairik; Abbas H. Abbas; Turki Y. Abdalla

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 1-12

A five-phase two-motor drive system with series connection of stator windings and decoupled dynamic control is considered in the present paper. The two-motor drive system is supplied from a single five-phase Space Vector Pulse Width Modulation (SVPWM) Voltage Source Inverter (VSI) and controlled using vector control scheme, provided that the stator windings are connected in series with appropriate phase transposition. The concept has been developed under the assumption that the inverter voltages are controlled in the stationary dq reference frame. A fuzzy logic based speed controller has been constructed and used to drive the two-motor in this work. The two-motor system. inverter system, and the fuzzy controller models are implemented and tested using SirnulinklMatlab facilities. The presented results show the validity of the model to do well for the sake of speed control under different operating conditions.

Proposed Algorithm of Tone Reservation PAPR Reduction In OFDM System

Hassan Abbas Nasir; Hussain K Chaiel

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 13-22

Orthogonal frequency division multiplexing (OFDM) has become a Popular modulation method in high-speed wireless communication systems due to its high data rates transmission capability and robustness against multipath fading effects. One of the major drawbacks of OFDIVI at the transmitter side is the high peak-to-average power ratio (PAPR) of the OFDM signal. In this paper, an algorithm is proposed to reduce the peak to average Power ratio of OFDM signal with large number of sub-carriers. This algorithm is based on lone reservation method. The computer simulation tests shoe that the suggested algorithm reduces the PAPR to a factor of S25 dB and needs less number of iterations as compared with the traditional tone reservation algorithm.

Optimal Sidelobes Reduction and Synthesis of Circular Array Antennas Using Hybrid Adaptive Genetic Algorithms

Ramzi S. AIi; Abdul Kareem S. Abdullah; Ali Abdulhadi Noaman

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 23-36

In this article, a hybrid optimization method has been proposed consisting of Adaptive Genetic Algorithms (AGAs) and Constrained Nonlinear Programming (NLP) to solve the problems of performance optimization of circular array antenna consisting parallel center feeding short dipoles elements with two complex nonlinear optimization problems. In the first problem, the hybrid optimization algorithm is used to reduce the value of sidelobe level in the circular array radiation pattern by finding the optimal values of the excitation coefficients of each element in the circular array. In the second problem, a synthesis of circular array with different forms of the desired radiation pattern is considered. Several examples are considered here to verify the validity of this method. Comparisons were made between the results of this method and the results obtained by (SGA) Standard Genetic Algorithm, and it is clearly shown that this method is more efficient and flexible in solving the problems of performance optimization of circular array antenna.

Neuro-FUZZY Control of Single Machine Infinite Bus Power System

Rsheed S. Jassim; Abbas H. Abbas; Abduladhem A. Ali

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 37-45

The excitation and governing control of generator flay an important role in improving the dynamic and transient stability of power system. Typically the excitation control and governing control are designed independently. This paper, presented Neuro-Fuzzy methods for the excitation and governing control Neuro-Fuzzy system is applied to generate two compensating signals to modify the controls during system disturbances. A single machine to infinite bus (SMIB) system is applied in simulation. The MATLAB SIMULIK and S-function technique is used to simulate the system and controllers

Hierarchical Phoneme Recognition Using Node-wise Relevance-Optimized Features

lntessar T. Hwaidy; Ali E. Hameed

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 46-53

In this paper, a hierarchical phoneme recognition system is proposed. The hierarchical approach is applied here to recursively partition the recognition problem into smaller and smaller sub-problems those are independently handled at the distinct nodes of the hierarchy. The nodes are individually set to characterize different properties of the input phoneme, or more precisely to make separate decisions on its pertinence to the different reference subgroups of phonemes. The full characterization of the input phoneme is achieved by traversing some root-to-leaf path through the hierarchy. The relationships between the different features of phonemes and their pertinence to the different reference subgroups are to be objectively characterized and optimized here. This involves specifying the decisive subset of features lbr each pertinence decision and neglecting the remaining features those are irrelevant to (or probably have negative effect on) that decision, at each node of the hierarchy. The optimization applied through the feature election process here, is not aimed at reducing the amount of features to he used in the recognition process, for the purpose of decreasing the time-complexity of the system, but, is interested in enhancing the decision making accuracy of the system by avoiding the misleading features.

Genetic Algorithm Based Optimal Design of a PID Controller for trajectory tracking of a Mobile Robot

Seaar J. Al; Duboni; Turki Y. Abdalla

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 54-65

This paper deals with the modeling and control strategies of the motion of wheeled mobile robot. The model of the mobile robot has two driving wheels and the azimuth and velocity are dependently controlled by two PID controllers. The PID controller is one of the earliest and famous industrial controllers. It has many advantages: It is economic, simple easy to be tuned and parameter. The tuning of these controllers is governed by system nonlinearities and continuous parameter variations. 1 his paper deals with the optimal design of a PID controller for path tracking of mobile robot by using genetic algorithms (GA). The designed controller is tested for different paths.

Variable Length Least Significant Bits Embedding

Abbas A. Jasim

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 66-75

A novel hiding system is proposed in this work which is based on Least Significant Bits (LSB) embedding of information such as speech in gray scale images.
The proposed hiding algorithm embeds the secrete information message bits in the least significant bits of the cover image pixels such that the number of secrete information bits to the embedded in least significant bits of cover image pixel is variable and determined randomly. So that cover image pixel may contain no secret information bit, one bit, two bits, or three bits according to the pseudo random number generator that generates integer numbers randomly between 0 and 3. The resulting image (the cover image within which the secret information is hidden) is called stego_image. Stego image is closely related to the cover image and does not show any details of the secret information. It ensures that the eavedroppers will not have any suspicion that message bits are hidden in the image aix! standard steganography detection methods cannot estimatc the locations in which the secret message bits are embedded and cannot estimate the locations in which the secrete information bits are hidden nor the number of bits embedded in cover image . The proposed system achieves perfect reconstruction of the secret message.

PREDICTION OF ULTIMATE STRENGTH OF AXIALY LOADED REINFORCED CONCRETE SHORT COLUMNS USING ARTIFICIAL NEURAL NETWORKS

Mustafa S. Zewalr; Nabeel A. Jasim

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 76-84

The present study deals with the analysis of short reinforced concrete columns subjected Ic axial load. One of efficient techniques is applied, known as artiflcial neural networks. The descent gradient backpropagation algorithm is employed for analysis. The optimum topology (which gives least mean square error for both training and testing with fewer number of epochs) is presented. The effects of the number of nodes in input and hidden layer(s), and selecting of learning rate and momentum coefficient, on the behaviour of neural network have been investigated. Due to slow convergence of results when using descent gradient backpropagation, the faster algorithm called “resilient backpropagation algorithm” has been used to improve the performance of the neural network and the results have been compared with those obtained using the descent gradient backpropagation algorithm.

EXPERIMENTAL ENVESTIGATION OF THE STRENGTH AND BEHAVIOR OF REINFORCED CONCRETE SPANDREL BEAMS UNDER REPEATED LOADS

Adi Adnan Abdul Razaq; Anis A. Mohamad-Ali

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 97-111

The main objective of this study is to investigate the effect of repeated load on the strength and behavior of spandrel beam by considering eight specimens divided into four groups based on the design methods; type of cross section of the spandrel beam and the type of loading. Two design methods, two types of loading and two types of cross sections for spandrel beam are considered, the first is a solid rectangular section, while the other is a hollow rectangular section.
the effect of repeated loads on the cracks width, deflections, torque and the angle of twist is studied using two stages of loading, the first stage is at the soft-cracking stage after occurring of cracks in the spandrel beam and the second stage is the yielding of the bottom longitudinal reinforcement of the floor beam.

Analytical Solution of Laminar Forced Convection in a Heated Channel Subjected to Reciprocating Flow

A.K.M Alshara; A.M.A. Regeb

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 112-132

Hydrodynamics and heat transfer in a fully developed laminar incompressible reciprocating channel flow subjected to a constant heat flux have been investigated analytically using similarity transformation. An exact analytical solution for the velocity, local and bulk temperature as well as of Nusselt number have been obtained. The effect of the parameters Pr, A0, 2 and Xl Dh on u1 , T T Nu and Nu are presented.
The results showed that the local Nusselt number is increased with increasing Womersly number () while the dimensionless temperature is increased with Womersly and decreased with amplitude (A0). Prandtl number has significant effect on local Nusselt number.
The results were found in very good agreement with that obtained numerically using finite volume method. The comparison with the experimental results of other authors gave a reasonable identification.

A new Measuring Criterion of the Performance of the Electromagnetic Flow meter

Muneer A. Ismael; Riadh H. AI-Rabeh

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 133-144

The weight function prescribing the sensitivity of the electromagnetic flowmeter (EMF) to the changes in the velocity profiles must be as much as possible uniformly distributed through the measuring volume. The most common used criterion of the weight function distribution is a statistical quantity (c criterion) which deals with only the axial component of the weight vector.
In the present work an attempt to introduce more revealing and accurate criterion to the EMF performance was studied. The curl of the weight function vector over the measuring volume has been considered and formulated (and termed as in such a mathematical expression that takes into account the contributions of the three components of the weight vector regardless of thc geometry of cross-sectional area of the flow. In addition, a numerical solution of a previously defined criterion (sj is presented here for a first time in order to compare the validity of the newly introduced criterion.
The results showed that the present new criterion e is closely harmonious with the previously defined criteria s and 8 in the conventional flow cases. The results and the configuration of the formula of the present criterion which is independent of the flow cross- sectional are led us to conclude that is more reliable and applicable than other existing criteria

Tensile-Property Characterization of Thermally Aged Cast Stainless Steels using Neural Networks.

Atef Nema

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 145-154

The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated and recorded by the Argonne National Laboratory.
Tensile data for several experimental and commercial heats of cast stainless steel (CF-8M) are presented for predicting the change in tensile flow and yield stresses and engineering stress-strain curve as a function of time and temperature of service in the light water reactors using Neural Networks.
Thermal aging increase the tensile strength of this type of steel. The result and correlation described by this work may be used for assessing thermal embitterment of cast stainless steel components.

The use of sand filter - activated carbon in the treatment effluents of Al-Kasak refinery in Mosul

Zena Fakhri Al-Hashmi

Basrah Journal for Engineering Science, Volume 10, Issue 1, Pages 155-168

The study focuses on using of sand and activated carbon filter for treating of Al-Kasak refinery wastewater The wastewater contains of many contaminations ,organic and chemicals materials. Many test performed such as pH, E.C, T.S,COD,BOD, Phenole,Oil,NH3, After and before treatment with filter in order to determine effluent characteristics .The highest T.S removal efficiency with sand filter was 93% and 90% for Oil .While the highest removal efficiency with activated carbon filter happened to Phenol which was 99% and for COD and BOD was(81- 90) % and (77-91)% continuously. The study show that the cycle time of 9hr gives best removal efficiency for organic wastewater specially for high organic load . It was recommended to use sand-Activated carbon filter to treat refinery wastewater because the effluents were within Limits of refinery waste water casting and river casting