مجلـــــة الجامعـــة الخليجيـــة - العدد الأول

PRACTICAL EXPERT FUZZY AUTO-TUNER FOR

DIGITALLY CONTROLLED DRIVES

Mazin Z. Othman – Head of Electrical and Electronic Engineering Department

College of Engineering - Gulf University –Kingdom of Bahrain

E-mail: dr.mazin@gulfuniversity.net

Abstract

Digital Speed or Position Controllers for motor drives are widely used in many industrial applications. The well – known proportional – integral (PI) controllers are the most popular ones which are used in CNC, robots or other industrial plants. This paper presents an expert system that based on practical procedure to auto-tune the digital PI speed controllers. The system consists, mainly of two parts, software and hardware. The software part is used automatically to identify the motor transfer function and determine the initial tuning parameters of digital (PI) controllers. This is called the course tuning level. Then a fine tuning level that consist fuzzy logic tuner that used to find the “best” tuning parameters of the PI controller. The hardware part is a digital card designed and based on the AT bus consists of two ADC channels and two DAC channels. The proposed design is tested on industrial type D.C motors. Experimental results show that the Auto- Tuning Expert System can efficiently be used to identify, tune and control the speed of the motors.

SOFTWARE ENHANCEMENT FOR EXTRACTING

PULMONARY FUNCTION TEST USING "MATLAB"

Khalaf Hasan Ali - Mechanical Engineering Department

College of Engineering - Gulf University - Kingdom of Bahrain

Email: Dr.Khalaf@gulfuniversity.net

Abstract

The parameters of pulmonary function test (PFT) can be extracted from the measurement of lung volumes. In this study, improvements in software's and hardware's are developed to increase the applicability degree of the Spirometers. The software improvement includes utilizing the effectiveness of the MATLAB package to perform the required signal conditioning, numerical integration, extracting the pulmonary function parameters, diagnosis of subject's case and other operations. The hardware improvement covers the designing of an essential ISA data acquisition card for connecting the physical parts to a personal computer.

ENHANCEMENT OF 3G MOBILE RADIOS

PERFORMANCE USING TURBO CODING AND

DIVERSITY

Muhanned Alfarras – CIS College – Gulf University –Kingdom of Bahrain

Email: Dr.muhanned @gulfuniversity.net

Dr.muhanned.alfarras@gmail.com

Abstract

This paper presents the performance of the turbo code over two channels

AWGN and the mobile radio channel. The mobile channel modelled as Rayleigh fading (Jakes model). The set of the simulation parameters is chosen to closely match the latest generation in universal mobile telecommunication system parameters. The types of turbo code used are Parallel Concatenated Convolutional Code (PCCC) and Serial Concatenated Convolution Code (SCCC). The bit error rate performance for different mobile speed, different frame size, and different number of iteration in the decoding are investigated. Furthermore one of the suggested approaches to enhance the performance of the third generation mobile is to combine turbo coding and diversity. Thus, this paper compared the performance of the PCCC and SCCC with and without diversity.

DICTIONARY BASED STEGANOGRAPHY

USING MULTIPLE FREQUENCY DOMAINS

Abstract

In this paper, we used a new technique for hiding text in a bitmap images. The technique based on using an index of the dictionary representing the characters of the secret messages instead of the characters themselves. The technique uses multiple frequency domains for embedding these indexes in an arbitrary chosen bitmap image. By using discrete cosine transform DCT, discrete wavelet transforms DWT, and a combination of both of them. We built a software package (YAD Stego) for implementing this technique, and we got very good results in terms of capacity of hiding, imperceptibility which are the most two important properties of steganography, the time of hiding the text, and the security issues.

CREATION OF A PLANNING RELATIONSHIP

BETWEEN CPM AND LINE OF BALANCE METHOD

ABSTRACT

Construction companies are often faced with projects containing multiple units wherein activities repeat as many as units there. These projects require schedules that ensure the uninterrupted usage of resources from an activity in one unit to a similar activity in the next unit. This research proves that, the critical path method (CPM) cannot assure this requirement because only technical precedence constraints are explicitly shown in (CPM) networks. The integrated (CPM) with Line of Balance (LOB) method is described in this paper as a planning technique to recognize the technical constraints of (CPM) and other additional constraints to ensure full utilization of resources. The research also introduces the critical path of activities as a new concept for the determination of the project duration. This critical path includes certain working gangs in an activity and activities between control points and it extends from project start to project finish.

THREE DIMENSINAL FLOW THROUGH A GAS

TURBINE POWER PLANT MAIN BURNER WITH

ANNULAR DIFFUSER

Arkan Kh. Husain Al-Taie – Mechanical Engineering Department

College of Engineering - Gulf University – Kingdom of Bahrain

Dr.Arkan@gulfuniversity.net

Abstract

A theoretical investigation of three dimensional, swirling, re-circulating, turbulent flows inside a gas turbine main combustor is made for various geometrical and inlet flow conditions. The work is divided into two parts: the first part is the mathematical model for the diffuser. A subsonic, compressible, steady state, and turbulent flow prediction in two dimensional (axi-symmetric) conical diffuser is analyzed for a 2.5 area ratio and angles until circulation takes place in the flow. Then, at this angle a snout is incorporated to correct the flow. The set of coupled non-linear equations is solved by using the finite volume procedure. The prediction procedure is put to predict the velocity components (axial and radial), and the Pressure. The second part presents a mathematical model for three dimensional, swirling, re circulating turbulent flows inside the main burner of a gas turbine power plant with optimally designed diffuser. The present model is restricted to single-phase, diffusion-controlled combustion, with radiation heat transfer. The mathematical model is built for the differential equations of: Continuity, momentum, stagnation enthalpy, concentration, radiation heat transfer, turbulence energy, its dissipation rate, and the mean square of concentration fluctuations. The simultaneous solution of these equations by means of a finite-volume solution algorithm yields the values of the variables at all internal grid nodes. The prediction procedure, composed of the mathematical model and its solution algorithm, is applied to predict the fields of variables within a representative combustor; the results are compared with some workers. The predicted results give the same trends as the measured ones, but the quantitative agreement is not always acceptable.

THE EFFICIENCY OF CONCRETE BLOCKS FOR

DOMESTIC DWELLINGS IN BAHRAIN

Saad F. Al Nuaimi Khamis Abdulla KhamisEng.

Architectural Dept. – College of engineering

Gulf university - Bahrain

Dr.Saad@gulfuniversity.net

Interior Design Engineer

Abstract

The thermal transmission through the walls and roof in the residential house constitutes more than half of the total peak cooling load. Insulating the building causes a significant reduction in the air-conditioning equipments’ capacity and consequently reduction in energy consumption, And savings energy by using insulating in the walls and roof, the type of masonry building material used for the walls effecting heat loss or gain. The results show that the lightweight concrete block with polystyrene insulation (sandwich block) (Figure 6), Have the lowest Thermal Transmittance U-value and it's the best block available in Bahrain for nonbearing wall structure.