Naeem M.N.,The University of Faisalabad |
Gamkhar M.,The University of Faisalabad |
Arshad S.H.,Iqra National University |
Shah A.G.,Government of Punjab
Journal of Mechanical Science and Technology | Year: 2013
This study gives a brief work on vibration characteristics of cylindrical shells submerged in an incompressible fluid. The shell is presumed to be structured from functionally graded material. The effect of the fluid is introduced by using the acoustic wave equation. Love's first order thin shell theory is utilized in the shell dynamical equations. The problem is framed by combining shell dynamical equations with the acoustic wave equation. Fluid-loaded terms are associated with Hankel function of second kind. Wave propagation approach is employed to solve the shell problem. Some comparisons of numerical results are performed for the natural frequencies of simply supported-simply supported, clamped-clamped and clamped-simply supported boundary conditions of isotropic as well as functionally graded cylindrical shells to check the validity of the present approach. The influence of fluid on the submerged functionally graded cylindrical shells is noticed to be very pronounced. © 2013 The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg.
Ahmad T.,Iqra National University |
Li X.,Beijing University of Posts and Telecommunications
Journal of Computational Information Systems | Year: 2012
In last few decades, number of efforts has been made to improve the visual quality of a degraded image. However, generating a desired high resolution image by means of the wavelet and other well-known transforms introduces many visual artifacts due to the Gibbs-like phenomena. In this paper, we propose a new algorithm based on curvelet transform to exploit its high energy compaction nature in order to reconstruct a high resolution image for the given low resolution input images. The low resolution images are first partially reconstructed by applying curvelet transform according to our proposed criteria. The proposed criteria are based on the calculated absolute kurtosis values of the input images. The partially reconstructed images are then registered using Marcel et. al. algorithm in spatial domain, which are then fused together using conventional POCS method. We apply our propose algorithm to the problem of restoring standard corrupt test images from noisy data and compare our results with those obtained via well-established technique. Our experiments show that the proposed algorithm outperforms the conventional super resolution technique both subjectively as well as in terms of the various estimation indices. Copyright © 2012 Binary Information Press.
Jan L.,Iqra National University |
Zafar M.H.,University of Peshawar |
Afridi S.K.,Iqra National University
Wireless Telecommunications Symposium | Year: 2016
Nonlinearities play an imperative role in performance of wireless communication systems. In this paper, High Power Amplifiers (HPA) have been used to check the performance of the proposed system by analyzing its amplitude, phase and their joint distortions using Multiple-Input Multiple-Output (MIMO) wireless communication system. This paper takes-in account the overall effects of HPA that provokes nonlinearities at the transmitter's end in a communication system. Therefore, a novel method for the HPA nonlinearities mitigation has been proposed to improve the performance of amplitude, phase and joint distortions in MIMO communication systems. The simulation results show an improvement in the overall effect of the MIMO system and enhance the input response on the transmitter side. Furthermore, this method has been proposed to exploit the benefits of the MIMO system to improve the Symbol Error Rate (SER) versus Signal to Noise Ratio (SNR) curves for amplitude, phase and their joint distortions. © 2016 IEEE.
Imtiaz W.A.,Iqra National University |
Ilyas M.,Iqra National University |
Khan Y.,Iqra National University
Infrared Physics and Technology | Year: 2016
This paper propose a new code to optimize the performance of spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system. The unique two-matrix structure of the proposed enhanced multi diagonal (EMD) code and effective correlation properties, between intended and interfering subscribers, significantly elevates the performance of SAC-OCDMA system by negating multiple access interference (MAI) and associated phase induce intensity noise (PIIN). Performance of SAC-OCDMA system based on the proposed code is thoroughly analyzed for two detection techniques through analytic and simulation analysis by referring to bit error rate (BER), signal to noise ratio (SNR) and eye patterns at the receiving end. It is shown that EMD code while using SDD technique provides high transmission capacity, reduces the receiver complexity, and provides better performance as compared to complementary subtraction detection (CSD) technique. Furthermore, analysis shows that, for a minimum acceptable BER of 10-9, the proposed system supports 64 subscribers at data rates of up to 2 Gbps for both up-down link transmission. © 2016 Elsevier B.V.
Mehr-E-Munir,Iqra National University |
Farooq U.,Iqra National University
Modern Problems of Radio Engineering, Telecommunications and Computer Science, Proceedings of the 13th International Conference on TCSET 2016 | Year: 2016
A novel technique for miniaturization of microstrip patch antenna is proposed for Portable and multifunctional Communication systems. Our proposed design consists of fractal patch, E-Shaped slot on fractal patch with first iteration and combination of H-Shape and L-Shape slots on the Ground plane. In this way we get smaller size antenna which is smaller than the conventional antenna. The most interesting feature of our proposed design is that we are getting multiband response in the frequency range of 1-8GHZ having Directivity in the range of 3.11dBi-5.84dBi, Gain in the range of -1.7dB- 6.23dB and good impedance bandwidth for desired bands. As we have used the fractal patch with substrate FR4.Co-axial cable is used as a feeding method. We also employed shorting pin between fractal patch and ground plane. By the combination of all these proposed technique size of antenna is reduced 91.72% and it produces multiband response while the impedance bandwidth and gain are satisfactory for each band. We can adjust different bands by changing position of shorting pin. This type of smaller size antenna has applications in mobile phone as well as for L-Band, S-Band and C-Band applications. © 2016 National University Lviv Polytechnic.
Afridi M.I.,Iqra National University
Applied Mechanics and Materials | Year: 2013
A cognitive routing system intelligently selects one protocol at a time for specific routing conditions and environment in MANET. Cognition or self learning can be achieved in a cognitive routing system for mobile ad-hoc network (MANET) through a learning system like learning automata or neural networks. This article covers the application of learning automata and neural network to achieve cognition in MANET routing system. Mobile Ad-hoc networks are dynamic in nature and lack any fixed infrastructure, so the implementation of cognition enhances the performance of overall routing system in these networks. In learning automata the process of learning is different from reasoning or decision making. Learning automata require little knowledge to take decisions. Neural network can be improved by increasing the number of neurons and changing parameters. Self training enhance neural network performance and it select suitable protocol for a given network environment. © (2013) Trans Tech Publications, Switzerland.
Afeef M.,Iqra National University
Life Science Journal | Year: 2014
Working Capital Management has an underlying impression on a firm's output performance. However, for larger firms, working capital does not usually constitute a sizeable fraction of their total assets. It is, therefore, perceived that an efficient management of working capital might not be an issue of marked concern for larger corporations. With this conjecture, this study moves on to determine the potential effect of working capital management on the profit performance of large-sized companies listed in Karachi Stock Exchange. To investigate, effect of working capital management was determined on profitability of a sample of 103 Pakistani large corporations listed in Karachi Stock Exchange for a period of six years from 2003 to 2008 which led to a total of 618 firm-year observations. Findings from the analyses suggested that indicators of working capital management had a very remarkable impact on profitability of firms under study.
Imtiaz W.A.,Iqra National University |
Ahmad N.,University of Malaya
International Journal of Communication Networks and Information Security | Year: 2014
Optical code division multiple access (OCDMA) provides another dimension to multiple access systems, in which each user is assigned a unique code. this allows each subscriber to simultaneously access the medium without any contention. however, simultaneous access of multiple users introduces multiple access interference (mai) which primarily deteriorates the performance of ocdma systems. this paper proposes a new code called diagonal double weight (ddw) code to elevate the performance and cardinality of spectral amplitude coding (sac) ocdma systems. performance of our proposed code is evaluated using comprehensive analytical analysis followed by simulation analysis. examination of bit error rate shows that ddw code along with single photodiode detection technique provides efficient performance, with added benefits of simplified design, large cardinality and ease of implementation.
Afridi M.I.,Iqra National University
International Journal of Bioinformatics Research and Applications | Year: 2013
The family of evolutionary or genetic algorithms is used in various fi elds of bioinformatics. Genetic algorithms (GAs) can be used for simultaneous comparison of a large pool of DNA or protein sequences. This article explains how the GA is used in combination with other methods like the progressive multiple sequence alignment strategy to get an optimal multiple sequence alignment (MSA). Optimal MSA get much importance in the fi eld of bioinformatics and some other related disciplines. Evolutionary algorithms evolve and improve their performance. In this optimisation, the initial pair-wise alignment is achieved through a progressive method and then a good objective function is used to select and align more alignments and profi les. Child and subpopulation initialisation is based upon changes in the probability of similarity or the distance matrix of the alignment population. In this genetic algorithm, optimisation of mutation, crossover and migration in the population of candidate solution reflect events of natural organic evolution. Copyright © 2013 Inderscience Enterprises Ltd.
Mehr-E-Munir,Iqra National University |
Mahmood K.,Iqra National University
Proceedings of 2015 International Conference on Emerging Technologies, ICET 2015 | Year: 2015
This paper presents software based design and analysis for a ground and patch slotted microstrip patch antenna for miniaturization and multi-band applications. The Patch slots are etched to achieve multiband operation while the ground slot technique is used to achieve miniaturization. The presented design uses FR4 as dielectric substrate with permittivity of 4.1 to support the Gain, radiation efficiency and other parameters of the antenna. The design is analyzed by CST (Computer Simulation Technology) simulator software. The resulted antenna design is a highly miniaturized antenna about 60.60% operating over a range of multiple resonant frequencies and also in mobile phone as well as for S-Band and C-Band applications. © 2015 IEEE.