Journal of Engineering

The emerging M-commerce (mobile +e-commerce) needs more support in operating systems in order to be successful over a wireless environment. The system needs to support a seamlessintegrati n to support voice, audio and conventional data. It should also support many users with guaranteed quality. In this paper, a new effective design protocol for Code Division Multiple Access(CDMA) mobile systems with Variable Spreading Factor (VSF) is presented, such that various Quality of Service (QoS) based on different traffic types can be provided. Increasing spreading factors can benefit the system because it will increase the desired signal strength linearly. The measured Bit Error Rate (BER) can be reduced 75 times with a long spreading factor. By taking advantage of this benefit, switching the spreading factors dynamically is proposed, based on the current load with multimedia traffic.These proposals are implemented in mobile and base stations, and the system performance measured. The results indicated that the proposed system can always maintain a desired quality forall voice connections.

The aim of the present work is to study the controlling of weld defects and dimensions by using robot cell which associated with MIG/MAG welding process. The base metal is evaluated through the chemical analysis, mechanical tests and micro-structure tests, filler metal is also selected and analyzed according to AWS specification. The various welding conditions are chosen to be as suitable as possible such as welding current, arc voltage, travel speed, stick out, protective gases and there is another effective parameter called as torch inclination angles, which has an obvious effect on the weld bead dimensions. Robotic arc welding has been applied and analyzed for the welding of a complex sheet metal product named as product X-11. The product X-11 required 33 are welds with total length of (182.8 cm) of welds. Two complete weld programs development are carried out. The weld program consists of two stages, which are the front side and the back side. The cycle time calculates for each program. It is obvious that the productivity is increase to about 186%. Some of quality control tests are curried out for the purpose of improving in weld quality. Some of inspections and tests are achieved for finding out the defects in the weldments in the mass production which is considered as attributes data. Pareto diagram is also set up to show the important defects in the production. The presence of defects in the final products may belong to many factors (eg. poor fits for welding parts, impurity of protective gases, etc.),

The destroying of Tafel region in many cases is not due to complication u'ith mass transfer , but
due to IR - drop effsct specially in dilute solutions ( i.e., of high resistivity) . Accordingly, the
corrosion behavior of reinforcement in reinforced concrete was investigated using electro -
chemical measurements. The work was carried out with small steel rods: cleaned and previously
oxidized embedded in resistance Portland cement concrete cylinders exposed to dry conditions' In
this investigation a theoretical model equation has been adopted including IR- drop term:
AE =AEA +RAi = -bclogicorr.+ bclog/Ai/+R /Ai/
In order to determine corrosion paiameters of iystem investigated (i.e., icorr., bc, and Rc. A)
equation above was based on the analysis of cathodic Polarization curve free from mass transf'er
effect .It has been found that the corrosion curent of pre- oxidized steel is higher than the cleaned
one , and this corrosion rate is concrete contaminant & time of exposure dependant. because of the
importance of electrical resistance of concrete & its relationship to the corrosion rate of reinforcing
steel. An attempt was made to find this resistance from the IR-drop term in the above mentioned
equation.

This paper presents a neural network based surface finish Prediction model in turning operation .
Orthogonal cutting tests were performed on mild steel using H.S.S cutting tool with different
cutting parameters cutting speed ,
feed and nose radius of the cutting tool . The collected data was
used to train feed forward back propagation neural network. The developed model has been tested
to preclict surface finish for various cutting conditions. The model was found to be powerful &
capable of accurate surface finish prediction for the range it had been trained but the accuracy
deteriorated as the cutting conditions were changed significantly'

A general mixed finite element formulation (u - w - ) is presented in this paper. This formulation includes the inertia effects and the soil skeleton is considered compressible. The application of this formulation in solving soil dynamic problems of saturated sand is made by governing the boundary conditions concerning the pore fluid pressure. A problem of soil column subjected to an instantly applied surface loal is solved. The solid skeleton and pore fluid pressure are each modelled with ten 4- noded isoparametric elements. The results are compared with those obtained by Zienkiewic z et al. (1988)\' It is concluded that the undamped response of displacement and pore pressure oscillates significantly with the increase of time step lenght.

A static analysis of cellular plate structures of linearly varying depth is presented by using the
simplified grillage method. The cellular plate structure in this study consists of top and bottom
flange plates (non-parallel) separated by longitudinal webs having varying depth. A variational
formulation of thin-walled beam element with linearly varying depth has been carried out for the
derivation of the stiffness matrix of the grillage members for various warping restraint effects. The
effect of warping restraint in stiffness is included by two methods, firstly; the implicit method
(through the torsional constant) and secondly; by the explicit method (as independent warping
degree of freedom). Two differer,t approaches are used to derive the torsional stiffness matrix,
namely:by the assumed displacement field and by the differential equation of equilibrium. The
effect of secondary shear stresses from the warping restraint is also considercd.
The varying cross section properties of the eguivalent grillage members are derived from the
properties of the actual cellular plate structure.
Several numerical examples and applications are presented . The results are compared with those
obtained from the flat plate / shell elements of MSCA.{ASTRAN program. Acceptable agreement is
obtained.

This paper adapted the neural network for the estimating of the direction of arrival (DOA). It uses
an unsupervised adaptive neural network with APEX algorithm to extract the principal components
that in turn, are used by Capon method to estimate the DOA, where by the PCA neural network we
take signal subspace only and use it in Capon (i.e. we will ignore the noise subspace, and take the
signal subspace only)

Advances in computer technology have introduced computers everywhere. One of the fields that the computers have entered is the field of process control and data acquisition systems. On the other hand, fuzzy control is emerging as an alternative to conventional control to control different systems. this paper is concerned with applying fuzzy control to a locally designed and manufactured process controller. This controller is designated by single point controller-1 (SPC-l)' It is basically a flexible and general-purpose, stand-alone, single-point controller. The CPU section of the SPC-1 is the AT89C5l general purpose microcontroller. The fuzzy control
algorithms were imple-mented as programs to be executed by this microcontroller. These programs were written in C language and were translated to machine language by Keil8051 C compiler p Vision V5.1.

The main purpose of this study is to investigated the single fillet weld design for built-up members
by using ftision welding and find the effects of welding power input on that design for member. In
this work, investigation of welding metal for Low carbon steel plate type St.52-3, thickness 6-8
rnm, which is to ensure good mechanical properties under high stresses for ( Welding metal , heat
affected Zone (HAZ) and base metal ). Also it can be explain, that the effects of welding processes
on the deformation and changes in mechanical and metallurgical properties due to high thermal
energy, results from welding process. This study involved: weld design, selection of suitable
electrode, evaluation of mechanical and metallurgical properties, the maximum allowable value of
sweep of welded mamber after ( fabrication and erection ) has been calculated, also leg and through
length have been calculated for the welded Zone. The main results of this study are :
- The value of sweep which occur before the erection and tightening is ( 29 mm. ).
- The leg and through length of welding metal which welded by electrode type
( E 7018 = OKUS ), its found equal to ( 4 mm. ).
The study results can ensure good mechanical and metallurgical properties for signal filled weld
( Built-up members ).

The escalating cost of construction projects combined with the competitive nature of the construction
industry requires the constant search for methods to increase the efficiency of such projects through
the elimination of unnecessary costs while maintaining as well as improving levels of quality and
performance desired.
Value Engineering (VE) offers an opportunity to achieve these goals, however, VE utilization by the
construction industry in Iraq remains limited as hypothesized by the researchers. Hence, the reasons
for this condition are worthy of investigation .Based on that, this research work has attempted to
examine the current status of implementation of value engineering methodology \\'within the Iraqi
construction industries, well as pinpointing areas of weakness in applying VE,
The validity of the research hypothesis was tested by carrying out both an open and closed
questionnaires, where a sample of Iraqi professional engineers -working in both the public and private
sectors have participated in responding to the questionnaires. Analysis of responses to the
questionnaires has indicated the validity of the research hypothesis as well as identifying significant
slips, which hinder the proper application of VE by the Iraqi construction industry. The researchers
has proposed certain remedial actions to overcome these slips which have initiated the second major
objective of the research work which entails the proposal of a \\"Value Engineering Management
System\\" (VEMS) to facilitate the systematic application of VE methodology and techniques by the
Iraqi engineers.
The evaluation process of the s)\\'stem by a number of experts has demonstrated approval and
possibility pf application in the field.

The research introduces a new mathematical model for computing the position of points in space
(X, Y, Z) by the intersection of inclined angles derived from the measured horizontal and vertical
angles using spherical trigonometry principles with the aid of the conventional surveying instrument
(Theodolite), The most probable value (m.p.v) of the position of a point should be computed by the
method of ieast squares when the redundancy in observations exists and then it provides us with the
precision indices for the computed coordinates.

The superhcater zone of the boiler is the convective heat transfer region of the boiler, that is the heat in this region mostly transferred by the convection between the flew gases outside and steam inside tubes. The factors that effected the heat transfer rate and heat transfer coefficient in the Mosiab power station boiler (980000kgihr capacity under pressure of 175bar) at its superlieater is studied here. The super heater is divided into two parts, primary and secondary super heater. Each part is
divided into many zones depending on the pipe size and material. The effect of boiler load mass flow rate of steam on the heat transfer rate, heat transfer coefficient, steam temperature is studied. It is concluded that as the load on the boiler increased the heat transfer rate is also increased and the heat transfer coefficient. The heat transfer coefficient in secondary superheater is less that that in the primary. The reduction in mass flow rate of steam increases the wall temperature of tubes because of low capacity of water to receive heat.

To render the environment amenable, is the great challenge to the man in general & to the architect in particular, since the beginning cf the creation up to this date, with a view to reaching physical, physiological, & psychological environment, as to ensure certain immunity from the problems of cross internal & external environmental pollution in \"Clean Buildings \", expressing his successful attempts at arriving at the results of the environment influences in the of the man\'s needs & desires and construing his relationship with the given environment to an actual existence features & components , on the ground that the planning of the building , designing its spaces & landmarks ,distributing its openings , & nature of the building materials used with the engineering services & technologies utilized in each work , resembles the function of the lenses which gathers the various environmental input & release the output & impacts which are \" the Clean Buildings \" The specific problem of the research is therefor, the absence of clear & specialized knowledge, of the basic relationship between architecture & environmental pollution influences through the
technical, technological & environmental constraints with the object of creating clean buildings of high performances.