Wireless signals are vulnerable to various security threats, like eavesdropping and jamming, due to the inherent broadcast nature of the wireless channel. Encryption may ensure the confidentiality of the data but does...
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Wireless signals are vulnerable to various security threats, like eavesdropping and jamming, due to the inherent broadcast nature of the wireless channel. Encryption may ensure the confidentiality of the data but does not guarantee successful communication among legitimate users in the presence of strong adversaries, like wideband jammers. In this scenario, hiding a secret signal in presence of another mundane ongoing communication is one of the ways to minimize its chances of getting intercepted. Wireless Steganography is a process of embedding a secret signal inside another signal that acts as a cover to hide the signal of interest. In this paper, we propose to encode secret bits into covert signals that are statistically indistinguishable from a hardware noise generated by a low-cost transmitter. As the covert signal resembles hardware noise, it can be transmitted over any waveform, making it adaptable and portable to any communication link. Each generated complex signal sample is merged with a cover signal sample, yielding a 50% embedding rate. We create the encoding and decoding models by creating a pair of complex-valued neural networks (NNs), which is trained in presence of another NN model, critic. The critic model differentiates between true hardware noise and encoder-generated covert signal, thus providing essential feedback to the NN pair to improve the encoding technique. The decoder undergoes a transfer learning process to adapt to the residual channel effects in over-the-air experiments. In an indoor testbed, we successfully decoded the covert communication that mimics a range of hardware noises and is transmitted using different modulation orders of cover OFDM waveform. Our steganalysis indicates that the covert signal can be generated to mimic specific hardware, which remains indistinguishable in different statistical tests. Our method performs an order of magnitude better in statistical steganalysis compared to the state-of-the-art method in this fi
Due to the increase in demand for electricity, the lack of fossil fuels, and the use of renewable energy sources, the use of energy storage systems becomes necessary. The use of storage systems in different parts of m...
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This article presents a frequency-domain analysis that models the behavior of Constant-on-Time (COT)-controlled buck converters in wide-input-output-range scenarios. Based on this analysis, a design strategy is propos...
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This work aims to develop a planar microwave sensor fabricated on a flexible polyimide substrate to monitor the water content of fruits nondestructively. The sensor is based on a planar loop resonator tuned with a con...
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Effects of photoionisation on the development and electron runaway of the initial discharge in atmospheric air under nanosecond pulse voltage were studied via twodimensional particle-in-cell/Monte Carlo collision *** ...
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Effects of photoionisation on the development and electron runaway of the initial discharge in atmospheric air under nanosecond pulse voltage were studied via twodimensional particle-in-cell/Monte Carlo collision *** was found that photoionisation has little effect at the beginning of the initial ***,as the discharge channel gradually develops towards the anode,photoionisation shows greater impacts on the morphology of discharge but has little influence on the velocity of discharge *** does not appear to have a decisive effect on the growth trend of the highest energy of runaway electrons,but it does affect the change rate of the highest energy and overall distribution of electron energy,resulting in a higher proportion of energetic *** difference in the distributions of the electron energy between the two cases,with and without considering photoionisation,can be attributed to the impact of photoionisation on the discharge morphology,which in turn distorted the electric *** spatial density distributions of the electrons produced by photoionisation further explained the *** authors’results explicitly demonstrate the influence of photoionisation on the development and the electron runaway of the initial discharge under nanosecond pulse voltage,which provides more comprehensive knowledge for the atmospheric air gap nanosecond pulse discharge physics.
Battery storage systems are subject to frequent charging/discharging cycles,which reduce the operational life of the battery and reduce system reliability in the long *** such,several Battery Management Systems(BMS)ha...
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Battery storage systems are subject to frequent charging/discharging cycles,which reduce the operational life of the battery and reduce system reliability in the long *** such,several Battery Management Systems(BMS)have been developed to maintain system reliability and extend the battery’s operative *** estimation of the battery’s State of Charge(SOC)is a key challenge in the BMS due to its non-linear *** paper presents a comprehensive review on the most recent classifications and mathematical models for SOC *** trends for SOC estimation methods are also presented.
Monitoring ship emissions poses an intricate interdisciplinary challenge, encompassing atmospheric science, transportation, information communication, and computer technology. Key stakeholders in this effort include m...
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In this study,a machine learning based method is proposed for creating synthetic eventful phasor measurement unit(PMU)data under time-varying load *** proposed method leverages generative adversarial networks to creat...
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In this study,a machine learning based method is proposed for creating synthetic eventful phasor measurement unit(PMU)data under time-varying load *** proposed method leverages generative adversarial networks to create quasi-steady states for the power system under slowly-varying load conditions and incorporates a framework of neural ordinary differential equations(ODEs)to capture the transient behaviors of the system during voltage oscillation events.A numerical example of a large power grid suggests that this method can create realistic synthetic eventful PMU voltage measurements based on the associated real PMU data without any knowledge of the underlying nonlinear dynamic *** results demonstrate that the synthetic voltage measurements have the key characteristics of real system behavior on distinct time scales.
Recently, several Delta-Sigma modulators (DSMs) with ultra-high quadrature-amplitude-modulation (QAM) order larger than one million, e.g., 1048576 and 4194304 QAM are reported. As different DSM works were implemented ...
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The substring edit error replaces a substring u of x with another string v, where the lengths of u and v are bounded by a given constant k. It encompasses localized insertions, deletions, and substitutions within a wi...
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