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Abrar Ahmed
Department of Electrical and Computer Engineering, COMSATS University Islamabad, Islamabad 44000, Pakistan

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Journal article
Published: 26 October 2020 in Energies
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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.

ACS Style

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 Style

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 (21):5599.

Chicago/Turabian Style

Zeeshan 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.

Journal article
Published: 09 June 2020 in IEEE Access
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Unmanned aerial vehicle (UAV) assisted cell-free communications hold promise for enhancing the coverage and capacity of heterogeneous cellular networks. However, the network interference in such scenarios must be accurately modeled for efficient system design. The spatial characteristics of the desired and interfering signals can be jointly modeled by considering the characteristics of the signal-to-interference ratio (SIR). This work proposes a generalized framework for modeling the spatial statistics of the SIR encountered in 3-D volumetric inter-vehicular communication channels. Though the novel paradigm of UAV-assisted cell-free vehicular communications is analyzed in particular, the proposed framework is more general in that it incorporates 3-D mobility at both link ends. Also, this framework is shown to include as its special cases, several notable 2-D propagation models of network interference including those for terrestrial vehicle-to-vehicle and fixed-to-vehicle scenarios. Analytical expressions are derived for the SIR level-crossing-rate (LCR), average-fade-duration (AFD), spatial auto-covariance (SAC), and coherence distance (CD). Both single- and multi-cluster scattering environments are analyzed and the impact of channel parameters such as the direction and velocity of mobile nodes as well as the altitudes of the UAV and scattering cluster(s) on the SIR fading statistics is investigated. Finally, some future extensions of this work are also discussed such as the integration of intelligent reflective surfaces in the propagation scenario to generate favorable channel conditions.

ACS Style

Ali Raza; Syed Junaid Nawaz; Shurjeel Wyne; Abrar Ahmed; Muhammad Awais Javed; Mohammad N. Patwary. Spatial Modeling of Interference in Inter-Vehicular Communications for 3-D Volumetric Wireless Networks. IEEE Access 2020, 8, 108281 -108299.

AMA Style

Ali Raza, Syed Junaid Nawaz, Shurjeel Wyne, Abrar Ahmed, Muhammad Awais Javed, Mohammad N. Patwary. Spatial Modeling of Interference in Inter-Vehicular Communications for 3-D Volumetric Wireless Networks. IEEE Access. 2020; 8 ():108281-108299.

Chicago/Turabian Style

Ali Raza; Syed Junaid Nawaz; Shurjeel Wyne; Abrar Ahmed; Muhammad Awais Javed; Mohammad N. Patwary. 2020. "Spatial Modeling of Interference in Inter-Vehicular Communications for 3-D Volumetric Wireless Networks." IEEE Access 8, no. : 108281-108299.

Journal article
Published: 01 December 2019 in Electronics
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In the last couple of decades, numerous energy management strategies have been devised to mitigate the effects of greenhouse gas emission, hence introducing the concept of microgrids. In a microgrid, distributed energy generators are used. Microgrid enables a point which ameliorates in exchanging power with the main grid during different times of day. Based on the system constraints, in this work, we aim to efficiently minimize the operating cost of the microgrid and shave the power consumption peaks. For this purpose, we introduce an improved binary bat (iBBat) algorithm which helps to schedule the load demand of smart homes and energy generation from distributed generator of microgrid to the load demand and supply. The proposed energy management algorithm is applied to both grid-connected and islanded modes of the microgrid. The constraints imposed on the algorithm ensure that the load of electricity consumer does not escalate during peak hours. The simulation results are compared with BBat and binary flower pollination algorithm, which validate that the iBBat reflects substantial reduction in operating cost of microgrid. Moreover, results also show a phenomenal reduction in the peak-to-average ratio of load demand from main the main grid.

ACS Style

Samia Abid; Turki Alghamdi; Abdul Haseeb; Zahid Wadud; Abrar Ahmed; Nadeem Javaid. An Economical Energy Management Strategy for Viable Microgrid Modes. Electronics 2019, 8, 1442 .

AMA Style

Samia Abid, Turki Alghamdi, Abdul Haseeb, Zahid Wadud, Abrar Ahmed, Nadeem Javaid. An Economical Energy Management Strategy for Viable Microgrid Modes. Electronics. 2019; 8 (12):1442.

Chicago/Turabian Style

Samia Abid; Turki Alghamdi; Abdul Haseeb; Zahid Wadud; Abrar Ahmed; Nadeem Javaid. 2019. "An Economical Energy Management Strategy for Viable Microgrid Modes." Electronics 8, no. 12: 1442.

Journal article
Published: 09 January 2019 in Technologies
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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.

ACS Style

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 Style

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 (1):9.

Chicago/Turabian Style

Sardar 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.

Article
Published: 02 August 2017 in Wireless Personal Communications
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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.

ACS Style

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 Style

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 (3):4285-4304.

Chicago/Turabian Style

Abrar 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.

Journal article
Published: 04 August 2016 in Applied Sciences
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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.

ACS Style

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 Style

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 (8):207.

Chicago/Turabian Style

Sardar 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.

Research article
Published: 25 August 2015 in PLOS ONE
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A tunable stochastic geometry based Three-Dimensional (3-D) scattering model for emerging land mobile radio cellular systems is proposed. Uniformly distributed scattering objects are assumed around the Mobile Station (MS) bounded within an ellipsoidal shaped Scattering Region (SR) hollowed with an elliptically-cylindric scattering free region in immediate vicinity of MS. To ensure the degree of expected accuracy, the proposed model is designed to be tunable (as required) with nine degrees of freedom, unlike its counterparts in the existing literature. The outer and inner boundaries of SR are designed as independently scalable along all the axes and rotatable in horizontal plane around their origin centered at MS. The elevated Base Station (BS) is considered outside the SR at a certain adjustable distance and height w.r.t. position of MS. Closed-form analytical expressions for joint and marginal Probability Density Functions (PDFs) of Angle-of-Arrival (AoA) and Time-of-Arrival (ToA) are derived for both up- and down-links. The obtained analytical results for angular and temporal statistics of the channel are presented along with a thorough analysis. The impact of various physical model parameters on angular and temporal characteristics of the channel is presented, which reveals the comprehensive insight on the proposed results. To evaluate the robustness of the proposed analytical model, a comparison with experimental datasets and simulation results is also presented. The obtained analytical results for PDF of AoA observed at BS are seen to fit a vast range of empirical datasets in the literature taken for various outdoor propagation environments. In order to establish the validity of the obtained analytical results for spatial and temporal characteristics of the channel, a comparison of the proposed analytical results with the simulation results is shown, which illustrates a good fit for 107 scattering points. Moreover, the proposed model is shown to degenerate to various notable geometric models in the literature by an appropriate choice of a few parameters.

ACS Style

Abrar Ahmed; Syed Junaid Nawaz; Sardar Muhammad Gulfam. A 3-D Propagation Model for Emerging Land Mobile Radio Cellular Environments. PLOS ONE 2015, 10, e0132555 .

AMA Style

Abrar Ahmed, Syed Junaid Nawaz, Sardar Muhammad Gulfam. A 3-D Propagation Model for Emerging Land Mobile Radio Cellular Environments. PLOS ONE. 2015; 10 (8):e0132555.

Chicago/Turabian Style

Abrar Ahmed; Syed Junaid Nawaz; Sardar Muhammad Gulfam. 2015. "A 3-D Propagation Model for Emerging Land Mobile Radio Cellular Environments." PLOS ONE 10, no. 8: e0132555.