Mehran University Research Journal of Engineering and Technology

6

Authors: Mazhar Hussain Peerzada, Anwaruddin Tanwari, Sadaf Aftab Abbasi

The present study was conducted to determine the impact of PE/CT (Polyester/Cotton) blend ratio on the low twist yarn properties. A range of yarn count with similar low twist was spun on ring machine with 70/ 30 and 30/ 70 PE/CT blend ratios. The yarn properties such as evenness, hairiness and strength were studied. It was observed that single end yarn and skein strength, elongation and hairiness were directly proportional to the ratio of polyester fibre in the blend. It was revealed from the experimental findings that the evenness and strength improved with an increase of proportion of polyester fibre. They also increased with increasing yarn count.

6

Authors: Abdul Salam Soomro , Abdul Qadeer Khan Rajput

The terrible tsunami disaster, on 26 December 2004 hit Krabi, one of the ecotourist and very fascinating provinces of southern Thailand including its various regions e.g. Phangna and Phuket by devastating the human lives, coastal communications and the financially viable activities. This research study has been aimed to generate the tsunami hazard preventing based lands use planning model using GIS (Geographical Information Systems) based on the hazard suitability analysis approach. The different triggering factors e.g. elevation, proximity to shore line, population density, mangrove, forest, stream and road have been used based on the land use zoning criteria. Those criteria have been used by using Saaty scale of importance one, of the mathematical techniques. This model has been classified according to the land suitability classification. The various techniques of GIS, namely subsetting, spatial analysis, map difference and data conversion have been used. The model has been generated with five categories such as high, moderate, low, very low and not suitable regions illustrating with their appropriate definition for the decision makers to redevelop the region.

8

Authors: Javed Ali Baloch , Imran Ali Jokhio , Sana Hoor Jokhio

WSNs (Wireless Sensor Networks) is an emerging area of research. Researchers worldwide are working on the issues faced by sensor nodes. Communication has been a major issue in wireless networks and the problem is manifolds in WSNs because of the limited resources. The routing protocol in such networks plays a pivotal role, as an effective routing protocol could significantly reduce the energy consumed in transmitting and receiving data packets throughout a network. In this paper the performance of SVR (Spatial Vector Routing) an energy efficient, location aware routing protocol is compared with the existing location aware protocols. The results from the simulation trials show the performance of SVR.

8

Authors: Zeeshan Ali Memon, Dur Muhammad Pathan, Tanweer Hussain

Two different control algorithms, sliding mode and MPC (Model Predictive Control) are employed to analyse the performance of a linear vehicle model equipped with an ACC (Adaptive Cruise Control) system. Both controllers are analysed under critical TM (Transitional Maneuvers) to investigate their suitability for the ACC system. The simulation results, for the same scenario, from both controllers' approach have been compared. The results show that the MPC is more robust than the SMC (Sliding Model Controller). The results show that the SMC algorithm is not suitable for the proposed vehicle model. The shortcomings of the SMC have been highlighted and the comparisons are made with the previous studies. The proposed approach can be useful for the selection of the appropriate controller for the given application.

8

Authors: Sania Bhatti, Tariq Jameel Saifullah Khanzada, Sheeraz Memon

Over the last few years, the deployment of WSNs (Wireless Sensor Networks) has been fostered in diverse applications. WSN has great potential for a variety of domains ranging from scientific experiments to commercial applications. Due to the deployment of WSNs in dynamic and unpredictable environments. They have potential to cope with variety of faults. This paper proposes an energy-aware fault-tolerant clustering protocol for target tracking applications termed as the FTTT (Fault Tolerant Target Tracking) protocol. The identification of RNs (Redundant Nodes) makes SN (Sensor Node) fault tolerance plausible and the clustering endorsed recovery of sensors supervised by a faulty CH (Cluster Head). The FTTT protocol intends two steps of reducing energy consumption: first, by identifying RNs in the network; secondly, by restricting the numbers of SNs sending data to the CH. Simulations validate the scalability and low power consumption of the FTTT protocol in comparison with LEACH protocol.

8

Authors: Imtiaz Hussain, Ali Asghar Memon, Bhawani Shankar Chowdhry

Condition changes at the rail surface due to the fallen tree leaves and/or other contaminations can cause the low adhesion levels which present a serious challenge for the traction/braking control systems to avoid the problem of wheel slip/slide. This paper presents a multiple model based method for the identification of the adhesion limit to overcome the problem of the wheel slip/slide in poor contact conditions. The proposed scheme is an indirect method that exploits the dynamic properties of the conventional solid axle wheelset in response to changes in contact condition at the wheel-rail interface avoiding difficult and expensive measurement requirements. A nonlinear model of lateral and yaw dynamics of a conventional solid axle wheelset is used for the study. The non-linearity and changes in the interaction with the rail are modelled by using a set of non-linear creep/slip curves. The scheme consists of a bank of Kalman filters based on the linearized wheelset models. Each Kalman filter in the filter bank is optimally tuned to operate in a specific contact condition. Normalized root mean square values from the residual of each filter calculated using time moving windows are assessed to identify the operating condition of the wheelset.

10

Authors: Muhammad Anwar Solangi, Rafiq Ahmed Memon, Ahsanullah Baloch

Numerical simulations of blood flow through plaque deposited arteries at different Reynolds numbers have been performed to investigate the impact of atherosclerosis on pressure drop and velocity profile at down stream. The predicated results are presented in terms of non-dimensional pressure isobars and velocity profiles at distinct Reynolds numbers and various levels of deposition at downstream of the artery segment. The scaled non-dimensional graph of pressure drop is also illustrated. The incompressible Navier-Stokes equation in the axi-symmetric frame of reference is solved numerically by employing FEM (Finite Element Method). Semi-implicit Taylor-Galerkin/pressure-correction scheme has been utilised to obtain steady state solutions. The effects of atherosclerosis on hemodynamic factors have been investigated. The results show that blockage disturbs the flow field in the wake of plaque deposited arteries and the trend of pressure and velocity is increasing as level of deposition or Reynolds number increases. The application of this research work can be utilised in the field of cardio vascular disease, design of device and further planning towards treatment.

10

Authors: Tariq Jamil SaifullahKhanzada, Javed Ali Baloch, Sania Bhatti

This paper presents the DME (Distance Measurement Error) estimation analysis for the wireless indoor positioning channel. The channel model for indoor positioning is derived and implemented using 8 WLAN (Wireless Local Area Network) antennas system compliant to IEEE 802.11 a/b/g standard. Channel impairments are derived for the TDOA (Time Difference of Arrival) range estimation. DME calculation is performed over distinct experiments in the TDOA channel profiles using 1,2,4 and 8 antennas deployed system. Analysis for the DME for different antennas is presented. The spiral antenna achieves minimum DME in the range of 1m. Data demographics scattering for the error spread in TDOA channel profile is analyzed to show the error behavior. The effect of increase in number of recordings on DME is shown by the results. Transmitter antennas behavior for DME and their standard deviations are depicted through the results, which minimize the error floor to less than 1 m. This reduction is not achieved in the literature to the best of our knowledge.

12

Authors: Laiq Khan , Sidar Mumtaz , Amjadullah Khattak

GMS (Generator Maintenance Scheduling) ranks very high in decision making of power generation management. Generators maintenance schedule decides the time period of maintenance tasks and a reliable reserve margin is also maintained during this time period. In this paper, a comparison of GA (Genetic Algorithm) and HS (Harmony Search) algorithm is presented to solve generators maintenance scheduling problem for WAPDA (Water And Power Development Authority) Pakistan. GA is a search procedure, which is used in search problems to compute exact and optimized solution. GA is considered as global search heuristic technique. HS algorithm is quite efficient, because the convergence rate of this algorithm is very fast. HS algorithm is based on the concept of music improvisation process of searching for a perfect state of harmony. The two algorithms generate feasible and optimal solutions and overcome the limitations of the conventional methods including extensive computational effort, which increases exponentially as the size of the problem increases. The proposed methods are tested, validated and compared on the WAPDA electric system.

12

Authors: Mujeebuddin Memon, Tanveer Hussain, Zeeshan Ali Memon

In order to increase the performance and to produce environment friendly aero engine, it is necessary to reduce the weight of the engine. A significant proportion of an engine's weight is due to the large castings used to form the main non-rotating structures. Replacement of these large castings with circular structures fabricated by assembling uniformly segmented circular components could provide a significant weight reduction. Due to various advantages of fabricated rigid structure of an aero engine casing, this article proposes that components should be assembled while considering optimum mating sequence to minimize assembly error and to reduce assembly time and cost. The algorithm based on connective assembly model is proposed to predict stage-by-stage assembly variations. A computer program is also developed to perform automated tolerance analysis and to find optimum mating sequence of component. The assembly variations are minimized based on three criteria of selection of assembly mating sequence. The results have shown that the three criteria may be used every time for tolerance analysis and to minimize variation propagations in the assembly of rigid circular structures.

14

Authors: Abdul Fatah Abbasi, Mujeebuddin Memon, Dur Muhammad Pathan

This paper provides the finite-difference solutions for closed contra-rotating discs flows at different disc speed ratios for a fixed value of rotational Reynolds number of order five. The flow structure reveals that when two discs rotate in opposite directions, the fluid mass outside the boundary layers is divided between two regions, which give rise to the formation of two-cell flow structure. In order to assess the different level of closures, two turbulence models low Reynolds number k-? model and low Reynolds number second moment closure have been employed to predict the essential features of the closed contra-rotating disc system. The most significant differences between the predictions of the two turbulence models occur at the peak of slower disc boundary layer, because flow is more complex and turbulent on this side. The comparison of predicted velocity profiles of two turbulence models show that the low Reynolds number second moment closure produce a better agreement with measurements, particularly along the boundary layers and in the central core region.

16

Authors: Muhammad Basharat , Ata-Ur-Rehman Tariq

Climatic variability across the command of LBDC (Lower Bari Doab Canal) has pernicious impact on equitable usage of irrigation water from head to tail. The main thrust of this study is to highlight the need for rationalizing water allowance within the canal command so that joint equity of both the canal and ground water availability to the farmers is ensured. Tail reach areas receive only about 212mm annual rainfall which is 45% of the rainfall at head reach (472mm). Whereas, the crop delta increases from head to tail, with minimum difference of 13mm and maximum of 147mm for oilseeds and sugarcane crops respectively. For wheat/cotton rotation, combined annual difference in delta between tail and head reach areas comes out to be 133mm. Adding this difference in crop delta to rainfall difference (260.6mm), a total difference comes out to be 393.6mm which is 33% of field delta for wheat/cotton crop rotation at head reach of LBDC command. This difference in irrigated hydrology across the command is responsible for successively increased depth to groundwater towards tail of the command. Accordingly, the tail end farmers are forced to incur higher costs per acre for groundwater pumping. This is because groundwater pumping from deeper depths in tail areas is about 3.5 times more costly as compared to head reach. So there is dire need to ensure equitable irrigation water availability in terms of quantity and cost, rationalization of water allowance is recommended to achieve this equity.

6

Authors: Arif Khan, Sabahat Arif, Khalid Alamgir

As the sustainable settlements have been included as a vital end product of all planning exercises, the architectural layouts should be well integrated with the sun path charts and the orientations of windows. Appropriate orientations can offer thermally indoor conditions besides physical and psychological comfort in any settlement at lesser energy demand. This investigation uses a vast number of computer simulations to visualize and make better decisions about heating and cooling requirements of a building and facades as a function of window orientation in composite climatic condition of Lahore. This study in particular evaluates the solar load in residential buildings responsive to the objective of sustainable new housing leading to thoughtful integration of architecture. The orientation of the buildings could then be essentially integrated to the current architectural and urban design practices in order to optimize the relationship between the given site ant the orientations for sustainable developments.

6

Authors: Saba Baloch, Javed Ali Baloch, Mukhtiar Ali Unar

In most digital communication systems, bandwidth limited channel along with multipath propagation causes ISI (Inter Symbol Interference) to occur. This phenomenon causes distortion of the given transmitted symbol due to other transmitted symbols. With the help of equalization ISI can be reduced. This paper presents a solution to the ISI problem by performing blind equalization using ANN (Artificial Neural Networks). The simulated network is a multilayer feedforward Perceptron ANN, which has been trained by utilizing the error back-propagation algorithm. The weights of the network are updated in accordance with training of the network. This paper presents a very effective method for blind channel equalization, being more efficient than the pre-existing algorithms. The obtained results show a visible reduction in the noise content.

8

Authors: Sabahat Arif, Arif Khan, Khalid Alamgir

Indoor thermal comfort in a building has been an important issue for the environmental sustainability. It is an accepted fact that their designs and planning consume a lot of energy in the modern architecture of 20th and 21st centuries. An appropriate orientation of a building can provide thermally comfortable indoor temperatures which otherwise can consume extra energy to condition these spaces through all the seasons. This experimental study investigates the potential effect of this solar passive design strategy on indoor temperatures and a simple model is presented for predicting indoor temperatures based upon the ambient temperatures.

8

Authors: Javed Ali Baloch, Imran Ali Jokhio, Faisal Karim Shaikh

SSN (Smart Sensor Network) systems could be used to monitor buildings with modern infrastructure, plant sites with chemical pollution, horticulture, natural habitat, wastewater management and modern transport system. To sense attributes of phenomena and make decisions on the basis of the sensed value is the primary goal of such systems. In this paper a Smart Spatially aware sensor system is presented. A smart system, which could continuously monitor the network to observe the functionality and trigger, alerts to the base station if a change in the system occurs and provide feedback periodically, on demand or even continuously depending on the nature of the application. The results of the simulation trials presented in this paper exhibit the performance of a Smart Spatially Aware Sensor Networks.

8

Authors: Tanweer Hussain, Mujeebuddin Memon, Zeeshan Ali Memon

Under the condition of elastic-plastic deformation, aero engine casings experience local stress and strain concentrations along with associated variations in load paths and stiffness. The accurate prediction of such behaviour is clearly necessary for design optimisation, potentially leading to beneficial weight savings. The present research seeks to tackle the objective of accurate characterisation of elasticplastic casing behaviour. The objective is to develop approximate techniques for predicting the elasticplastic behaviour, for both generalised load-displacement responses (i.e. for global response) and notch stress-strain responses. Accurate prediction of the stress-strain distribution at a notch is difficult and existing notch prediction techniques can only be used for small strains. This paper seeks to develop novel techniques for predicting large elastic-plastic notch strain and associated stresses, with application to aero engine casing notches. The repeated local joints at the spoke-shell casing are of particular interest as they are the most likely sites for plastic deformation and possibly crack initiation. These local joints incorporate realistic notch-type features and the load cases cover a range of loading combinations, to develop insight and understanding of the elastic-plastic behaviour. This work analyse a double edgenotched flat bar with semicircular notches and a representative case of actual aero engine casing-type structures in a more simplified form. The investigation was carried out for structures for which stress and total strain are related by a power law. The equivalent stress at a notch can be estimated, given the value of n, by a linear interpolation between the stresses for a cases n=1 and n=0. The application of the notch stress-strain prediction method is illustrated through use of examples of notch components. The predictions are compared with results obtained using finite element analyses and approximate methods proposed by Nueber and Glinka.

10

Authors: Junaid Ali Abbasi , Sarwar Ali Abbasi , Mukhtar Hussain Sahir

This research paper focuses on the process of machining complex and varying contour aerofoil parts used in aerospace industry like wings, blades of turbine and diffusers, etc. The main theme is to enhance productivity and on the other hand achieving accurate machining results for complex profile parts. The research consists of three main parts viz. Accurate and optimized tool path generation of complex profile, understanding and conversion of a 5-axes machine kinematics into mathematical relationships and developing a post processor which converts cutter location file into machine readable file, and finally a time and accuracy study has been made and compared with techniques used previously for machining of such components. Tool path is generated on CAM software from where CL (Cutter Location) file is generated, then by use of mathematical calculations post processor is developed and used for the conversion of that CL file into machine readable file. Time and accuracy analysis has been made in the end on an impeller blade machining. Tool paths generated in CAM software requires to be very closely analyzed in order to ensure collision free tool paths as movement in all 5-axes increases the chances of collision of head to work piece or with the table. For the study of 5-axes machine kinematics and calculations, a general 5-axes machine having 3 linear axes and two axes in rotary/tilting table has been used. By applying mathematical relationships using rotational matrix theorem and dot product of two vector quantities, equations were derived for rotary and tilting axes and then written in programming language (Visual C++) for line to line conversion of CL file into machine readable file. For the generation of CL file three different tool paths were generated. First process was the roughing of the area between every two adjacent blades then the next step was to finish the surface of the blades and the leading/trailing edge and the last process was to finish the hub surface of the impeller. The cutting parameters like feed, speed, axial depth of cut, radial depth of cut are dependent on the spindle power of the machine and the type of the material of part to be machined and that of the cutter itself. The selection of the size of the cutting tool used for the machining of each process is also dependant on the minimum area between two adjacent surfaces of the blades of impeller and maximum curvature of the blade from shroud surface to hub surface in order to avoid collision of the cutting tool with the blade surfaces. In the end, how the new approach has benefited is analyzed. The need for research on new approach was very demanding as to manufacture complex profile parts mostly used in aerospace industry with traditional machining approaches causes unpredictable delays due to manual calculations, inaccurate machining results like poor surface finish, tool breakage, etc, as well as requirement of various jigs/fixtures and skilled workers for accomplishing the task all the time. Now by adopting the approach as explored in this research gives a lot of advantages over traditional manufacturing approach. Some important features compared are presented in the tabular form.

12

Authors: Attaullah Shah, Saeed Ahmad

Experimental research on the shear capacity of HSRC (High Strength Reinforced Concrete) beams is relatively very limited as compared to the NSRC (Normal Strength Reinforced Concrete) beams. Most of the Building Codes determine the shear strength of HSRC with the help of empirical equations based on experimental work of NSRC beams and hence these equations are generally regarded as un-conservative for HSRC beams particularly at low level of longitudinal reinforcement. In this paper, 42 beams have been tested in two sets, such that in 21 beams no transverse reinforcement has been used, whereas in the remaining 21 beams, minimum transverse reinforcement has been used as per ACI-318 (American Concrete Institute) provisions. Two values of compressive strength 52 and 61 MPa, three values of longitudinal steel ratio and seven values of shear span to depth ratio have been have been used. The beams were tested under concentrated load at the mid span. The results are compared with the equations proposed by different international building codes like ACI, AASHTO LRFD, EC (Euro Code), Canadian Code and Japanese Code for shear strength of HSRC beams.From comparison, it has been observed that some codes are less conservative for shear design of HSRC beams and further research is required to rationalize these equations.

14

Authors: Muhammad Asif Chaudhry, Habib-Ur-Rehman

Globally there are about 25,500 storage reservoirs with total storage volume of about 6,464 Bcm. The maximum number of reservoirs are in North America, i.e. 7205 with the total storage volume of about 1,844 Bcm, whereas minimum number of reservoirs are in Central Asia, i.e. 44, with the total storage volume of about 148 Bcm. Over the globe, average annual reservoir storage loss due to sedimentation varies from 0.1-2.3%, however, average annual world storage loss is about 1.0%. In order to combat the storage loss, the techniques used globally are: watershed management, dredging of deposited sediments, sediment routing/sluicing, sediment bypassing, density current venting and sediment flushing through reservoir, separately and also in combination. Each approach has its own limitations, depending on the site conditions. Sediment flushing technique is used by two ways i.e. Drawdown flushing and Emptying and Flushing. In Emptying and Flushing, the reservoir is emptied before the flood season, resulting in the creation of river-like flow conditions in the reservoir. The flow velocities in the reservoir are increased to such an extent that deposited sediments are remobilized and transported through the low level outlets provided slightly above the original riverbed level with sufficient flow capacity. Flushing is not a new technique and has been experienced for the last 6 decades on several reservoirs of the world. The results of the study reveal that there are about 50 reservoirs which are flushed, out of which flushing data is available for about 22 reservoirs only. However 6 reservoirs have been found with successful application of flushing operation and all other are flushed with low flushing efficiency. Flushing has been successfully implemented at Baira-India, Gebidem-Switzerland, Gmund-Austria, Hengshan-China, Palagnedraswitzerland, Santo-Domingo-Venezuela Reservoirs, while the unsuccessfully flushed reservoirs are: Chinese reservoirs, Gaunting, Heisonglin, sanmenxia, Shuicaozi, Naodehai, Nanqin, Guernsey-USA, Ichari-India, ouchi-Kurgan and Zemo-Afchar of former USSR, sufid-Rud-Iran, Warsak-Pakistan, Jensanpei-Taiwan, Khashm El Gibra-Sudan, Mangahao-Newzealand, and Cachi of Costa Rica.

14

Authors: Kamran Ansari, Ashfaque Ahmed Memon, Naeem Aziz Memon

A numerical analysis of the ridges on the bed of wide, open channels and their effects on the distribution of secondary currents and wall shear is undertaken using CFD (Computational Fluid Dynamics). The presence of the lines of boil, consisting of low speed streaks, periodically in the transverse direction, is reported in the literature due to the presence of the ridges. In the present work, simulations are run on channel sections with varying the number of ridges on the bed and the size of these ridges. The effect of these variations on the flow structures and shear stress distribution in wide open channels is reported. The results offer an interesting insight into the 3D (Three-Dimensional flow structures involved and the link between flow structures and bed morpho-dynamics in prismatic channels.

20

Authors: Zeeshan Ali Memon, Saleh Jumani, Javed Larik

Automotive vehicle following systems are essential for the design of automated highway system. The problem associated with the automatic vehicle following system is the string stability of the platoon of vehicles, i.e. the problem of uniform velocity and spacing errors propagation. Different control algorithm for the longitudinal control of a platoon are discussed based on different spacing policies, communication link among the vehicles of a platoon, and the performance of a platoon have been analysed in the presence of disturbance (noise) and parametric uncertainties. This paper presented the PID (Proportional Integral Derivative) feedback control algorithm for the longitudinal control of a platoon in the presence of noise signal and investigates the performance of platoon under the influence of sudden acceleration and braking in severe conditions. This model has been applied on 6 vehicles moving in a platoon. The platoon has been analysed to retain the uniform velocity and safe spacing among the vehicles. The limitations of PID control algorithm have been discussed and the alternate methods have been suggested. Model simulations, in comparison with the literature, are also presented.

4

Authors: Mazhar Hussain Peerzada, Awais Khatri, Sadaf Aftab Abbasi

Much less has been done on failure characteristics of 3D (Three Dimensional) woven fabrics. This work is to attempt to this need. Shear behavior is key characteristic and play direct role to the performance of woven fabrics. In this study, three different 3D weave structures have been used to analyze the fabric shear rigidity. Shear analysis has been carried out in both directions using Kawabata evaluating system. Based on the results, a relationship of shear rigidity (G) and shear hysteresis are compared and analyzed in zero and 90o direction of fabric.

6

Authors: Sheeraz Memon, Faisal Karim Shaikh, Javed Ali Baloch

The environment affects largely the performance of automatic speaker recognition. This work investigates the effects of clinical environment on the task of speaker recognition. For this task we have used two sets of speakers, a clinical set which consists of speech samples from 70 clinically depressed speakers and a control set which comprises of 68 clinically non-depressed speakers. The MFCCs (Mel Frequency Cepstral Coefficients) are applied for feature extraction, and a number of modeling methods such as GMM-EM (Gaussian Mixture Models Based on Expectation Maximization), GMM based on Kmeans (GMM-Kmeans), GMM-LBG based on Linde Buzo Gray, and GMM -ITVQ based on Information Theoretic Vector Quantization are used. The different modeling methods are evaluated for the novel speech corpus. The results suggest that the speaker recognition rates for the depressed speakers are lower (60-71%) than for the non-depressed speakers (79-89%). This paper further investigate the performance of VQ (Vector Quantization) based Gaussian modeling, and proposes a novel approach called GMM-ITVQ. The results suggest that GMM-EM has the higher recognition rates however, the performance of GMMITVQ is comparable to GMM-EM.

6

Authors: Uzma Syed, Roger H. Wardman, Rafique Ahmed Jhatial

In this research software was designed for assessing the inter-yarn zone fabric porosity of Tencel plain weave fabrics in terms of flow of dye liquor by using Matlab. Fabric images were captured at constant light intensity and magnification using an optical microscope and image analysis software. The captured images were first converted into monochrome image and then into binary image at specific threshold value (150). The percentage of white pixels in the binary image were calculated which assessed the fabric porosity in percentage. The loosely woven fabric gives higher percentage of fabric porosity as compared to the tightly woven fabric. This software has potential to calculate the fabric porosity of plain weave fabric manufactured from any type of raw material.

8

Authors: Taj Mohammad Khan, Muhamad Ahmed Choudhry

In machine vision, occlusions problem is always a challenging issue in image based mapping and navigation tasks. This paper presents a multiple view vision based algorithm for the development of occlusion-free map of the indoor environment. The map is assumed to be utilized by the mobile robots within the workspace. It has wide range of applications, including mobile robot path planning and navigation, access control in restricted areas, and surveillance systems. We used wall mounted fixed camera system. After intensity adjustment and background subtraction of the synchronously captured images, the image registration was performed. We applied our algorithm on the registered images to resolve the occlusion problem. This technique works well even in the existence of total occlusion for a longer period.

8

Authors: Abdul Salam Soomro, Abdul Qadeer Khan Rajput , Sarfraz Hussain Solangi

The earthquake triggered enormous landslides on 8th October 2005 in the various areas of Pakistan especially in Balakot Region. This research paper fulfilled the urge to develop alternative landslide planning based on the consideration of landslide preventing measures using GIS (Geographical Informaton Systems) techniques. This specific type of land use planning differs from traditional type of land use planning due to consideration of the probable hazard of landslide disaster by applying zonation methodology for finding the appropriate suitable areas for various development purposes. The various parameters e.g. elevation, slope angle, forest/ vegetations, faults, landslide zones, and rainfall were utilized as GIS data themes in the vector format. The different GIS techniques were used: (i) Clipping the data layers; (ii) Spatial analysis by converting the vector layers into raster format; (iii) Classification of data themes into certain classes; (iv) Overlaying the data themes and (v) Map calculation techniques through GIS standard software. This applied research has found that various different regions such as high suitable, moderate suitable, low suitable and unsuitable may be considered as preventive measures from the probable hazard of the landslide disaster in future for rehabilitation and redevelopment purpose which can save human lives, residential and commercial infrastructure in future. It is believed that the various predicted regions for preventing landslide hazards can be very beneficial to the decision makers for the redevelopment of the region in future.

10

Authors: Suhail Zaki Farooqui

An innovative mould free method for the fabrication of ultimate light weight small wind turbine blades made out of composites has been suggested in this paper. The method has been practically applied with very satisfactory results. The method is low cost and is specifically suitable for individual small wind turbine makers. The airfoils used are simple to shape and possess good Cl/Cd characteristics. The blades are crafted using galvanized iron sheets, aluminum pipes, hard paper and fiberglass. A computer program is included with tip correction features to design the blades at the required power rating, wind speed, tip speed ratio and the chosen constant angle of attack. Results of the program run for designing 250 and 500 watt wind turbine blades at 8 m/s wind speed and tip speed ratios of 5.5 are tabulated. Performance results of the blades thus produced are also discussed.

10

Authors: Zubair Ahmed Memon , Nafees Ahmed Memon, Afaq Hyder Chohan

Construction sector together with service, manufacturing, agriculture and mining sectors is the main contributors of the Pakistan's GDP (Gross Domestic Product) and economic growth. It is also a key indicator in determining the economic performance of the country. As the issues of globalization and trades deregulation, stringer requirements of time, cost, quality and advancement of technologies have become more critical, the sector has to find ways to enhance its operational efficiency and effectiveness. IT (Information Technology) as a key enabler has been recognized to be an inseparable tool to sustain business and become more competitive. This paper gives an overview of the current status of IT application and presents the significant results from PCI (Pakistan Construction Industry). The result of survey also highlights the challenges to the construction industry of Pakistan before implementing the IT techniques. A statistical method 'Average Index' is used to analyze the collected data and statistical hypothesis testing is conducted to know the difference between the parameters. The survey produced knowledge about the use of computers, hardware and software, communication and strategies for the use of IT. The use of spread sheets, word processor, CAD (Computer Aided Drafting) in general has increased and the use of model based CAD software has increased among the major key players of construction industry. The use of project webs and electronic trade in the industry is not started properly. From the analysis it is concluded that construction firms in Pakistan are mostly using manual procedures and the use of

10

Authors: Dur Muhammad Pathan, Mukhtiar Ali Unar, Zeeshan Ali Memon

This paper proposes a fuzzy logic controller for design of autopilot of a ship. Triangular membership functions have been use for fuzzification and the centroid method for defuzzification. A nonlinear mathematical model of an oil tanker has been considered whose parameters vary with the depth of water. The performance of proposed controller has been tested under both course changing and trajectory keeping mode of operations. It has been demonstrated that the performance is robust in shallow as well as deep waters.

12

Authors: Fayyaz Hussain Asghar, Muhammad Javed Hyder

Computational analysis of film cooling effectiveness using novel semicircular hole shapes with streamwise inclination of 30o has been carried out. Pitch to diameter ratios of 3.0 has been investigated. Reynolds Averaged Navier-Stoke equation solver FLUENT with standard k- turbulence model is used for simulations. Coolant to mainstream blowing ratios is varied from 1.33-2.0. It is observed that for the streamwise region x/D<20 the centerline and laterally averaged effectiveness values from a row of semicircular holes are higher than that from a row of circular holes due to the less jet lift-off of coolant jet. For a row of semicircular holes, mean coolant jet heights are lower than that from a row of circular holes. Simulations for two rows of inlined and staggered semicircular holes are also carried out and the results are compared with single row of full circular holes. It is found that centerline and laterally averaged effectiveness values from 2 rows of semicircular holes are much higher than a single row of full circular hole case at all streamwise regions at all blowing ratios tested. Among all the cases studied, effectiveness values from two staggered rows of semicircular holes are found to be highest. Jet lift-off is found minimum from two staggered row of semicircular holes. For all cases studied, the mean coolant jet heights from two staggered rows of semicircular holes are found minimum. Results for counter rotating vortex pairs from all cases at plane normal to mainstream

16

Authors: Aamir Hanif, Mohammad AhmedChoudhry, Tahir Mehmood

VSC (Voltage Source Converter) feed-forward control strategy of DVR (Dynamic Voltage Restorer) for an in-phase voltage injection scheme is proposed in this paper to tackle not only voltage sags and swells in the utility supply but also phase jumps as well. The proposed strategy utilizes a time based ramp at a clock rate of 50Hz to obtain a 3-phase reference signal that is compared with actual 3-phase utility voltage to obtain an error signal. If the error in each phase of the utility voltage is greater than zero then appropriate control signals are generated. The switching devices in VSC are switched accordingly to compensate voltage sags, swells and phase jumps in the utility voltage that propagates to load. For the mitigation of voltage sags, swells and phase jumps, the unipolar SPWM control is used. The proposed control system response time to compensate voltage sag, swell and phase jump through switching of VSC devices is less than 10ms whereas ITIC curve and SEMI-F-47 standard suggest a target of 20ms. Load voltage THD is below 5% as per IEEE Std. 519-1992. These results show that employed control strategy has an excellent capability of voltage restoration with acceptable harmonic distortion, within specified time frame for smooth and clean power flow to load. MATLAB®/Simulink® SimpowerSystem tool box has been used to obtain simulation results to verify the effectiveness and validity of the proposed control strategy to improve the quality of the power delivered to the load.

8

Authors: Muhammad Munawar, Nadeem A. Mufti, Hassan Iqbal

Optimization of surface roughness has been one of the primary objectives in most of the machining operations. Poor control on the desired surface roughness generates non conforming parts and results into increase in cost and loss of productivity due to rework or scrap. Surface roughness value is a result of several process variables among which machine tool condition is one of the significant variables. In this study, experimentation was carried out to investigate the effect of machine tool condition on surface roughness. Variable used to represent machine tool's condition was vibration amplitude. Input parameters used, besides vibration amplitude, were feed rate and insert nose radius. Cutting speed and depth of cut were kept constant. Based on Taguchi orthogonal array, a series of experimentation was designed and performed on AISI 1040 carbon steel bar at default and induced machine tool's vibration amplitudes. ANOVA (Analysis of Variance), revealed that vibration amplitude and feed rate had moderate effect on the surface roughness and insert nose radius had the highest significant effect on the surface roughness. It was also found that a machine tool with low vibration amplitude produced better surface roughness. Insert with larger nose radius produced better surface roughness at low feed rate.

8

Authors: Syed Asif Ali Shah, Wajiha Shah, Faisal Karim Shaikh

Flow time analysis is a powerful concept to analyze the flow time of any arriving customer in any system at any instant. A load management mechanism can be employed very effectively in any queueing system by utilizing a system which provides probability of dual service rate. In this paper, we develop and demonstrate the flow and service processes transition diagram to determine the flow time of a customer in a load management late arrival state dependent finite discrete time queueing system with dual service rate where customers are hypogeometrically distributed. We compute the probability mass function of each starting state and total probability mass function. The obtained analytical results are validated with simulation results for varying values of arrival and service probabilities.

10

Authors: Faisal Karim Shami , Arshad Hussain Qureshi , Muhammad Mansha

Flow-induced vibration is of prime concern to the designers of heat exchangers subjected to high flows of gases or liquids. Excessive vibration may cause tube failure due to fatigue or fretting-wear. Tube failure results in, expensive plant upholding and suffers loss of production. Therefore, tube failure due to unwarranted vibration must be avoided in process heat exchangers and nuclear steam generators, preferably at design stage. Such vibration problems may be avoided through a comprehensive flowinduced vibration analysis before fabrication of heat exchangers. However, it requires an understanding of vibration mechanism and parameters related to flow-induced vibration. For an accurate vibration analysis, it is of prime importance to have good estimates of structural and flow related dynamic parameters. Thus dynamic parameters such as added mass and damping are of significant concern in a flow regime. The purpose of this paper is to provide an overview of our state of knowledge and role of dynamic parameters in flow-induced vibration on tube bundles due to current trend of larger heat exchangers. The present paper provides published data, analysis, evaluation, formulation, and experimental studies related to hydrodynamic mass and damping by a large number of researchers. Guidelines for experimental research and heat exchangers design related to added mass and damping mechanisms subjected to both single and two-phase flow are outlined in this paper.

12

Authors: Abdul Fattah Abbasi, Mujeebuddin Memon, Ahsanullah Baloch

This paper describes the numerical predictions of isothermal closed rotor-stator flows. Steady-state finite-difference solutions are sought for two gap ratios and two rotational Reynolds number in the axisymmetric cylindrical polar coordinate frame of reference. Low Reynolds number models, low Reynolds number k-? and second moment closure models have been used to compute the necessary description of the flow inside the rotor-stator system without superpose flow. The most important dissimilarities among the computational calculations of both the turbulence models obtain at the lower radial locations, where k-? model predicted the premature transitional predictions from laminar to turbulent flow. The major feature of this computational work is the emergence of four regions of the flow i.e. source, sink and two boundary layers. Computed velocity components of both models are compared against the experimental measurements. Low Reynolds number second moment closure shows the improved level of matching with data, particularly on apex of the boundary layers and recirculating core in the middle of the rotor-stator cavity.