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In this paper, a novel modified optimization algorithm is presented, which combines Nelder-Mead (NM) method with a gradient-based approach. The well-known Nelder Mead optimization technique is widely used but it suffers from convergence issues in higher dimensional complex problems. Unlike the NM, in this proposed technique we have focused on two issues of the NM approach, one is shape of the simplex which is reshaped at each iteration according to the objective function, so we used a fixed shape of the simplex and we regenerate the simplex at each iteration and the second issue is related to reflection and expansion steps of the NM technique in each iteration, NM used fixed value of [Formula: see text], that is, [Formula: see text] = 1 for reflection and [Formula: see text] = 2 for expansion and replace the worst point of the simplex with that new point in each iteration. In this way NM search the optimum point. In proposed algorithm the optimum value of the parameter [Formula: see text] is computed and then centroid of new simplex is originated at this optimum point and regenerate the simplex with this centroid in each iteration that optimum value of [Formula: see text] will ensure the fast convergence of the proposed technique. The proposed algorithm has been applied to the real time implementation of the transversal adaptive filter. The application used to demonstrate the performance of the proposed technique is a well-known convex optimization problem having quadratic cost function, and results show that the proposed technique shows fast convergence than the Nelder-Mead method for lower dimension problems and the proposed technique has also good convergence for higher dimensions, that is, for higher filter taps problem. The proposed technique has also been compared with stochastic techniques like LMS and NLMS (benchmark) techniques. The proposed technique shows good results against LMS. The comparison shows that the modified algorithm guarantees quite acceptable convergence with improved accuracy for higher dimensional identification problems.
Armaghan Mohsin; Yazan Alsmadi; Ali Arshad Uppal; Sardar Muhammad Gulfam. A modified simplex based direct search optimization algorithm for adaptive transversal FIR filters. Science Progress 2021, 104, 1 .
AMA StyleArmaghan Mohsin, Yazan Alsmadi, Ali Arshad Uppal, Sardar Muhammad Gulfam. A modified simplex based direct search optimization algorithm for adaptive transversal FIR filters. Science Progress. 2021; 104 (2):1.
Chicago/Turabian StyleArmaghan Mohsin; Yazan Alsmadi; Ali Arshad Uppal; Sardar Muhammad Gulfam. 2021. "A modified simplex based direct search optimization algorithm for adaptive transversal FIR filters." Science Progress 104, no. 2: 1.
Electricity is widely used around 80% of the world. Electricity theft has dangerous effects on utilities in terms of power efficiency and costs billions of dollars per annum. The enhancement of the traditional grids gave rise to smart grids that enable one to resolve the dilemma of electricity theft detection (ETD) using an extensive amount of data formulated by smart meters. This data are used by power utilities to examine the consumption behaviors of consumers and to decide whether the consumer is an electricity thief or benign. However, the traditional data-driven methods for ETD have poor detection performances due to the high-dimensional imbalanced data and their limited ETD capability. In this paper, we present a new class balancing mechanism based on the interquartile minority oversampling technique and a combined ETD model to overcome the shortcomings of conventional approaches. The combined ETD model is composed of long short-term memory (LSTM), UNet and adaptive boosting (Adaboost), and termed LSTM–UNet–Adaboost. In this regard, LSTM–UNet–Adaboost combines the advantages of deep learning (LSTM-UNet) along with ensemble learning (Adaboost) for ETD. Moreover, the performance of the proposed LSTM–UNet–Adaboost scheme was simulated and evaluated over the real-time smart meter dataset given by the State Grid Corporation of China. The simulations were conducted using the most appropriate performance indicators, such as area under the curve, precision, recall and F1 measure. The proposed solution obtained the highest results as compared to the existing benchmark schemes in terms of selected performance measures. More specifically, it achieved the detection rate of 0.92, which was the highest among existing benchmark schemes, such as logistic regression, support vector machine and random under-sampling boosting technique. Therefore, the simulation outcomes validate that the proposed LSTM–UNet–Adaboost model surpasses other traditional methods in terms of ETD and is more acceptable for real-time practices.
Zeeshan Aslam; Nadeem Javaid; Ashfaq Ahmad; Abrar Ahmed; Sardar Muhammad Gulfam. A Combined Deep Learning and Ensemble Learning Methodology to Avoid Electricity Theft in Smart Grids. Energies 2020, 13, 5599 .
AMA StyleZeeshan Aslam, Nadeem Javaid, Ashfaq Ahmad, Abrar Ahmed, Sardar Muhammad Gulfam. A Combined Deep Learning and Ensemble Learning Methodology to Avoid Electricity Theft in Smart Grids. Energies. 2020; 13 (21):5599.
Chicago/Turabian StyleZeeshan Aslam; Nadeem Javaid; Ashfaq Ahmad; Abrar Ahmed; Sardar Muhammad Gulfam. 2020. "A Combined Deep Learning and Ensemble Learning Methodology to Avoid Electricity Theft in Smart Grids." Energies 13, no. 21: 5599.
Background and Objective: Vibrio cholerae continues to emerge as a dangerous pathogen because of increasing resistance to a number of antibiotics. This paper provides a solution to emerging antibiotic resistance by introducing novel proteins as vaccine candidates against cholera. Materials and Methods: Vibrio cholerae genome versatility is a hurdle for developing a vaccine to combat diarrhoeal infection, so its core gene information was used to determine a potential vaccine candidate. Whole genome sequence data of more than 100 Vibrio cholerae strains were used simultaneously to get core genome information. The VacSol pipeline based on reverse vaccinology was selected to address the problem of safe, cheap, temperature-stable, and effective vaccine candidates which can be used for vaccine development against Vibrio cholerae. VacSol screens vaccine candidates using integrated, well-known, and robust algorithms/tools for proteome analysis. The proteomes of the pathogens were initially screened to predict homology using BLASTp. Proteomes that are non-homologous to humans are then subjected to a predictor for localization. Helicer predicts transmembrane helices for the protein. Proteins failing to comply with the set parameters were filtered at each step, and finally, 11 proteins were filtered as vaccine candidates. Results: This selected group of vaccine candidates consists of proteins from almost all structural parts of Vibrio cholerae. Their blast results show that this filtered group includes flagellin A protein, a protein from the Zn transporter system, a lipocarrier outer membrane protein, a peptidoglycan-associated protein, a DNA-binding protein, a chemotaxis protein, a tRNA Pseuriudine synthase A, and two selected proteins, which were beta lactamases. The last two uncharacterized proteins possess 100% similarity to V. albensis and Enterobacter, respectively. Tertiary structure and active site determination show a large number of pockets on each protein. Conclusions: The most interesting finding of this study is that 10 proteins out of 11 filtered proteins are introduced as novel potential vaccine candidates. These novel vaccine candidates can result in the development of cost-effective and broad-spectrum vaccines which can be used in countries where cholera is a major contributor to diarrheal disease.
Samia Zeb; Amjad Ali; Sardar Muhammad Gulfam; Habib Bokhari. Preliminary Work Towards Finding Proteins as Potential Vaccine Candidates for Vibrio cholerae Pakistani Isolates through Reverse Vaccinology. Medicina 2019, 55, 195 .
AMA StyleSamia Zeb, Amjad Ali, Sardar Muhammad Gulfam, Habib Bokhari. Preliminary Work Towards Finding Proteins as Potential Vaccine Candidates for Vibrio cholerae Pakistani Isolates through Reverse Vaccinology. Medicina. 2019; 55 (5):195.
Chicago/Turabian StyleSamia Zeb; Amjad Ali; Sardar Muhammad Gulfam; Habib Bokhari. 2019. "Preliminary Work Towards Finding Proteins as Potential Vaccine Candidates for Vibrio cholerae Pakistani Isolates through Reverse Vaccinology." Medicina 55, no. 5: 195.
Extension of usable frequency spectrum from microwave to millimeter-wave (mmWave) is one of the key research directions in addressing the capacity demands of emerging 5th-generation communication networks. This paper presents a thorough analysis on the azimuthal multipath shape factors and second-order fading statistics (SOFS) of outdoor and indoor mmWave radio propagation channels. The well-established analytical relationship of plain angular statistics of a radio propagation channel with the channel’s fading statistics is used to study the channel’s fading characteristics. The plain angle-of-arrival measurement results available in the open literature for four different outdoor radio propagation scenarios at 38 GHz, as well as nine different indoor radio propagation scenarios at 28 GHz and 38 GHz bands, are extracted by using different graphical data interpretation techniques. The considered quantifiers for energy dispersion in angular domain and SOFS are true standard-deviation, angular spread, angular constriction, and direction of maximum fading; and spatial coherence distance, spatial auto-covariance, average fade duration, and level-crossing-rate; respectively. This study focuses on the angular spread analysis only in the azimuth plane. The conducted analysis on angular spread and SOFS is of high significance in designing modulation schemes, equalization schemes, antenna-beams, channel estimation, error-correction techniques, and interleaving algorithms; for mmWave outdoor and indoor radio propagation environments.
Sardar Muhammad Gulfam; Syed Junaid Nawaz; Konstantinos B. Baltzis; Abrar Ahmed; And Noor M. Khan. Characterization of Fading Statistics of mmWave (28 GHz and 38 GHz) Outdoor and Indoor Radio Propagation Channels. Technologies 2019, 7, 9 .
AMA StyleSardar Muhammad Gulfam, Syed Junaid Nawaz, Konstantinos B. Baltzis, Abrar Ahmed, And Noor M. Khan. Characterization of Fading Statistics of mmWave (28 GHz and 38 GHz) Outdoor and Indoor Radio Propagation Channels. Technologies. 2019; 7 (1):9.
Chicago/Turabian StyleSardar Muhammad Gulfam; Syed Junaid Nawaz; Konstantinos B. Baltzis; Abrar Ahmed; And Noor M. Khan. 2019. "Characterization of Fading Statistics of mmWave (28 GHz and 38 GHz) Outdoor and Indoor Radio Propagation Channels." Technologies 7, no. 1: 9.
Extension of usable frequency spectrum from microwave to millimeter-wave (mmWave) range is one of the key research direction in addressing the capacity demands of 5thgeneration (5G) land mobile radio communication networks. This paper presents a thorough analysis on the second-order fading statistics of indoor mmWave range radio propagation channels. The well established analytical relationship of plain angular statistics of a radio propagation channel with the channel's fading statistics is utilized to study the fading characteristics of indoor mmWave radio propagation channels. The plain angle-of-arrival (AoA) measurement results published in the open literature for three different indoor radio propagation scenarios at 28GHz band are extracted by using different graphical interpretation techniques. The extracted plain AoA statistics are extended to study the dispersion of energy in angular domain and second-order fading statistics of the channel. The considered quantifiers for energy dispersion in angular domain and second-order fading statistics are true standard-deviation, angular spread, angular constriction, and direction of maximum fading; and spatial coherence distance, spatial auto-covariance, average fade duration (AFD), and level-crossing-rate (LCR); respectively. The conducted analysis on angular spread and second-order fading statistics is of high significance in designing antenna-beams, error-correction techniques, channel estimation and equalization schemes, modulation schemes, and interleaving algorithms; for 28GHz indoor radio propagation environments.
Sardar Muhammad Gulfam; Syed Junaid Nawaz; Konstantinos B. Baltzis. Characterization of second-order fading statistics of 28GHz indoor radio propagation channels. 2018 7th International Conference on Modern Circuits and Systems Technologies (MOCAST) 2018, 1 -4.
AMA StyleSardar Muhammad Gulfam, Syed Junaid Nawaz, Konstantinos B. Baltzis. Characterization of second-order fading statistics of 28GHz indoor radio propagation channels. 2018 7th International Conference on Modern Circuits and Systems Technologies (MOCAST). 2018; ():1-4.
Chicago/Turabian StyleSardar Muhammad Gulfam; Syed Junaid Nawaz; Konstantinos B. Baltzis. 2018. "Characterization of second-order fading statistics of 28GHz indoor radio propagation channels." 2018 7th International Conference on Modern Circuits and Systems Technologies (MOCAST) , no. : 1-4.
A three dimensional (3D) geometric channel model is proposed for ground-to-air (G2A) and air-to-ground (A2G) communication links. A low-elevated ground station (GS) and a high-elevated air station (AS) are taken at foci points of a virtual bounding ellipsoid corresponded from known knowledge of delay of longest propagation path. The effective region of scatterers around the GS is designed on the basis of this ellipsoid truncated by the average rooftop level (or average height of sea waves) and ground plane. Closed-form expressions for joint and marginal probability density functions (PDFs) of angle of arrival (AoA) observed at AS and GS in correspondence with azimuth and elevation angles are derived. Furthermore, closed-form expressions for density of energy with respect to the delay of arriving multipath waves corresponded from both the elevation and azimuth AoA are derived independently when observed from either end of the communication link. Moreover, effect of different physical parameters of the channel on distribution of energy in angular and temporal domains is presented. The comparison of analytical results with results of a notable model is also presented. In order to verify the derived analytical expressions, a comparison of analytical results with the performed simulation results is presented, which shows a good match.
Sardar Muhammad Gulfam; Syed Junaid Nawaz; Abrar Ahmed; Mohammad N. Patwary. Angle and time of arrival characteristics of 3D air-to-ground radio propagation environments. Computer Communications 2017, 112, 22 -37.
AMA StyleSardar Muhammad Gulfam, Syed Junaid Nawaz, Abrar Ahmed, Mohammad N. Patwary. Angle and time of arrival characteristics of 3D air-to-ground radio propagation environments. Computer Communications. 2017; 112 ():22-37.
Chicago/Turabian StyleSardar Muhammad Gulfam; Syed Junaid Nawaz; Abrar Ahmed; Mohammad N. Patwary. 2017. "Angle and time of arrival characteristics of 3D air-to-ground radio propagation environments." Computer Communications 112, no. : 22-37.
In delivering fifth generation (5G) communication networks, the fundamental advancements in the scale of antenna arrays, density of networks, mobility of communicating nodes, size of cells, and range of frequencies necessitate the derivation of an appropriate and reliable channel model. A tunable three dimensional (3-D) geometric channel model comprehending the mobility of user terminal together with high degree of flexibility in modelling the shape, orientation, and scale of the scattering region is proposed. Characterization of Doppler spectrum, quantization of multipath dispersion in angular domain, and second order fading statistics of the radio propagation channel is presented. Mathematical expressions for joint and marginal probability density function of Doppler shift and multipath power are derived for this advanced 3-D hollow geometric scattering model. Next, an analysis on the Doppler spectrum is presented, where the impact of various physical channel parameters on its statistical characteristics is analyzed. Since, the quantification of multipath dispersion in 3-D angular domain is of vital importance for designing large scale planner antenna arrays with very high directional resolution for emerging 5G communications, therefore, a thorough analysis on the multipath shape factors (SFs) of the proposed analytical 3-D channel model is conducted. Finally, the analysis on SFs is extended for characterization of second order fading statistics of multipath channels.
Abrar Ahmed; Syed Junaid Nawaz; Sardar Muhammad Gulfam. Small-Scale Fading Statistics of Emerging 3-D Mobile Radio Cellular Propagation Channels. Wireless Personal Communications 2017, 97, 4285 -4304.
AMA StyleAbrar Ahmed, Syed Junaid Nawaz, Sardar Muhammad Gulfam. Small-Scale Fading Statistics of Emerging 3-D Mobile Radio Cellular Propagation Channels. Wireless Personal Communications. 2017; 97 (3):4285-4304.
Chicago/Turabian StyleAbrar Ahmed; Syed Junaid Nawaz; Sardar Muhammad Gulfam. 2017. "Small-Scale Fading Statistics of Emerging 3-D Mobile Radio Cellular Propagation Channels." Wireless Personal Communications 97, no. 3: 4285-4304.
Abrar Ahmed; Sardar Muhammad Gulfam; Syed Junaid Nawaz; Mohmammad N. Patwary. Doppler spectrum and second order fading statistics of emerging 3-D radio cellular propagation channels. 2017 11th European Conference on Antennas and Propagation (EUCAP) 2017, 3157 -3161.
AMA StyleAbrar Ahmed, Sardar Muhammad Gulfam, Syed Junaid Nawaz, Mohmammad N. Patwary. Doppler spectrum and second order fading statistics of emerging 3-D radio cellular propagation channels. 2017 11th European Conference on Antennas and Propagation (EUCAP). 2017; ():3157-3161.
Chicago/Turabian StyleAbrar Ahmed; Sardar Muhammad Gulfam; Syed Junaid Nawaz; Mohmammad N. Patwary. 2017. "Doppler spectrum and second order fading statistics of emerging 3-D radio cellular propagation channels." 2017 11th European Conference on Antennas and Propagation (EUCAP) , no. : 3157-3161.
Massive multiple-input multiple-output (massive-MIMO) is foreseen as a potential technology for future 5G cellular communication networks due to its substantial benefits in terms of increased spectral and energy efficiency. These advantages of massive-MIMO are a consequence of equipping the base station (BS) with quite a large number of antenna elements, thus resulting in an aggressive spatial multiplexing. In order to effectively reap the benefits of massive-MIMO, an adequate estimate of the channel impulse response (CIR) between each transmit–receive link is of utmost importance. It has been established in the literature that certain specific multipath propagation environments lead to a sparse structured CIR in spatial and/or delay domains. In this paper, implicit training and compressed sensing based CIR estimation techniques are proposed for the case of massive-MIMO sparse uplink channels. In the proposed superimposed training (SiT) based techniques, a periodic and low power training sequence is superimposed (arithmetically added) over the information sequence, thus avoiding any dedicated time/frequency slots for the training sequence. For the estimation of such massive-MIMO sparse uplink channels, two greedy pursuits based compressed sensing approaches are proposed, viz: SiT based stage-wise orthogonal matching pursuit (SiT-StOMP) and gradient pursuit (SiT-GP). In order to demonstrate the validity of proposed techniques, a performance comparison in terms of normalized mean square error (NCMSE) and bit error rate (BER) is performed with a notable SiT based least squares (SiT-LS) channel estimation technique. The effect of channels’ sparsity, training-to-information power ratio (TIR) and signal-to-noise ratio (SNR) on BER and NCMSE performance of proposed schemes is thoroughly studied. For a simulation scenario of: 4×64 massive-MIMO with a channel sparsity level of 80% and signal-to-noise ratio (SNR) of 10dB, a performance gain of 18dB and 13dB in terms of NCMSE over SiT-LS is observed for the proposed SiT-StOMP and SiT-GP techniques, respectively. Moreover, a performance gain of about 3dB and 2.5dB in SNR is achieved by the proposed SiT-StOMP and SiT-GP, respectively, for a BER of 10−2, as compared to SiT-LS. This performance gain NCME and BER is observed to further increase with an increase in channels’ sparsity.
Babar Mansoor; Syed Junaid Nawaz; Sardar Muhammad Gulfam. Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing. Applied Sciences 2017, 7, 63 .
AMA StyleBabar Mansoor, Syed Junaid Nawaz, Sardar Muhammad Gulfam. Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing. Applied Sciences. 2017; 7 (1):63.
Chicago/Turabian StyleBabar Mansoor; Syed Junaid Nawaz; Sardar Muhammad Gulfam. 2017. "Massive-MIMO Sparse Uplink Channel Estimation Using Implicit Training and Compressed Sensing." Applied Sciences 7, no. 1: 63.
A geometry-based three-dimensional (3D) novel stochastic channel model for air-to-ground (A2G) and ground-to-air (G2A) radio propagation environments is proposed. The vicinity of a ground station (GS) is modelled as surrounded by effective scattering points; whereas the elevated air station’s (AS) vicinity is modelled as a scattering-free region. Characterization of the Doppler spectrum, dispersion in the angular domain and second order fading statistics of the A2G/G2A radio communication channels is presented. Closed-form analytical expressions for joint and marginal probability density functions (PDFs) of Doppler shift, power and angle of arrival (AoA) are derived. Next, the paper presents a comprehensive analysis on the characteristics of angular spread on the basis of shape factors (SFs) for A2G/G2A radio propagation environments independently in both the azimuth and elevation planes. The analysis is further extended to second order statistics of the fading channel; where the behaviour of the level crossing rate (LCR), average fade duration (AFD), auto-covariance and coherence distance for the A2G/G2A radio propagation environment is studied. Finally, the impact of physical channel parameters, such as the mobility of AS, the height of AS, the height of GS and the delay of the longest propagation path, on the distribution characteristics of Doppler shift, angular spread and second order statistics is thoroughly studied.
Sardar Muhammad Gulfam; Syed Junaid Nawaz; Abrar Ahmed; Mohammad N. Patwary; Qiang Ni. A Novel 3D Analytical Scattering Model for Air-to-Ground Fading Channels. Applied Sciences 2016, 6, 207 .
AMA StyleSardar Muhammad Gulfam, Syed Junaid Nawaz, Abrar Ahmed, Mohammad N. Patwary, Qiang Ni. A Novel 3D Analytical Scattering Model for Air-to-Ground Fading Channels. Applied Sciences. 2016; 6 (8):207.
Chicago/Turabian StyleSardar Muhammad Gulfam; Syed Junaid Nawaz; Abrar Ahmed; Mohammad N. Patwary; Qiang Ni. 2016. "A Novel 3D Analytical Scattering Model for Air-to-Ground Fading Channels." Applied Sciences 6, no. 8: 207.
This paper first presents an extension of a notable three dimensional (3D) channel model for air-to-ground (A2G) radio propagation environments, from the plain distribution of angular energy to the quantization of multipath shape factors (SFs). Next, the paper presents a comprehensive analysis on the characteristics of multipath SFs for A2G radio propagation environments observed at both ends of the link. The analysis include the impact of various physical channel parameters on angular spread, true standard deviation, angular constriction, and direction of maximum fading. These SFs are obtained by exploiting the analytical and empirical results available in the literature for the distribution of energy in 3D angular space. Finally, a mechanism for classification of A2G propagation environments into taxiing, en-route, and take-off scenarios on the basis of SFs is presented.
Sardar Muhammad Gulfam; Syed Junaid Nawaz; Abrar Ahmed; Mohammad N. Patwary. Analysis on multipath shape factors of air-to-ground radio communication channels. 2016 Wireless Telecommunications Symposium (WTS) 2016, 1 -5.
AMA StyleSardar Muhammad Gulfam, Syed Junaid Nawaz, Abrar Ahmed, Mohammad N. Patwary. Analysis on multipath shape factors of air-to-ground radio communication channels. 2016 Wireless Telecommunications Symposium (WTS). 2016; ():1-5.
Chicago/Turabian StyleSardar Muhammad Gulfam; Syed Junaid Nawaz; Abrar Ahmed; Mohammad N. Patwary. 2016. "Analysis on multipath shape factors of air-to-ground radio communication channels." 2016 Wireless Telecommunications Symposium (WTS) , no. : 1-5.