摘要 :
This letter presented a pencil-on-paper-based ecofriendly capacitive touchpad fabricated through a low-cost lab- and solvent-free fabrication process. Economical, readily available, and biodegradable materials, such as pencil and ...
展开
This letter presented a pencil-on-paper-based ecofriendly capacitive touchpad fabricated through a low-cost lab- and solvent-free fabrication process. Economical, readily available, and biodegradable materials, such as pencil and paper, have been used for sensor fabrication. A touchpad based on five such sensors has been developed and evaluated by using it as a user control interface to on/off LEDs and displaying results on LCD and mobile app. The graphite sensors in the user interface have been shielded from the direct interaction of humans and the environment using changeable cling film to make the interface reliable and reusable. The interface can be used in different conditions and users by changing the shielding film. Simultaneously, the system's functionality will remain consistent and functioned similarly to the conventional touch sensors and buttons. These recyclable and easily arrayed touch sensor-based keypads can contribute to future developments in disposable and lightweight interfaces for human–machine interface, medical and healthcare applications, smart packaging, security monitoring, and consumer products.
收起
摘要 :
This letter presents a novel hybrid method that leverages deep learning to exploit the multiresolution analysis capability of the wavelets, in order to denoise a photoplethysmography (PPG) signal. Under the proposed method, a nois...
展开
This letter presents a novel hybrid method that leverages deep learning to exploit the multiresolution analysis capability of the wavelets, in order to denoise a photoplethysmography (PPG) signal. Under the proposed method, a noisy PPG sequence of length
$N$
is first decomposed into
$L$
detailed coefficients using the fast wavelet transform (FWT). Then, the clean PPG sequence is reconstructed with the help of a custom feedforward neural network (FFNN) that provides the binary weights for each of the wavelet subsignals outputted by the inverse-FWT block. This way, all those subsignals which correspond to noise or artefacts are discarded during reconstruction. The FFNN is trained on the Beth Israel Deaconess Medical Center dataset and a custom video-PPG dataset, whereby we compute the mean squared-error (MSE) between the denoised sequence and the reference clean PPG signal, and compute the gradient of the MSE for the back-propagation. Simulation results reveal that our proposed method reduces the MSE of the PPG signal significantly (compared to the MSE of the original noisy PPG signal): by 56.40% for Gaussian noise, by 64.01% for Poisson noise, 46.02% for uniform noise, and by 72.36% for salt-and-pepper noise (with “db10” mother wavelet).
收起
摘要 :
New proposed coal-fuelled power plants can significantly increase the power generation capacity of Pakistan but in the absence of emission reduction technology such generators cause pollution in the surrounding environment. An app...
展开
New proposed coal-fuelled power plants can significantly increase the power generation capacity of Pakistan but in the absence of emission reduction technology such generators cause pollution in the surrounding environment. An approach has been developed to meet national environmental quality standards for environmentally friendly operation of coal plants. Software developed for this article is shown to be an adequate tool for estimation of per kWh emissions of nitrogen oxides, sulphur oxides, carbon oxides, and particulate matter from coal-fired power plants. The software also calculates and compares electricity production costs with and without emissions charges. Work presented in this article determines that although the proposed implementation of emission reduction technologies increases electricity production cost it does not change the merit order of coal on the supply curve.
收起
摘要 :
We report a novel noncontact method for dehydration monitoring. We utilize a transmit software-defined radio (SDR) that impinges a wideband radio-frequency (RF) signal (of frequency 5.23 GHz) onto either the chest or the hand of a...
展开
We report a novel noncontact method for dehydration monitoring. We utilize a transmit software-defined radio (SDR) that impinges a wideband radio-frequency (RF) signal (of frequency 5.23 GHz) onto either the chest or the hand of a subject who sits nearby. Furthermore, another SDR in the closed vicinity collects the reflected RF signals. The two SDRs exchange orthogonal frequency division multiplexing (OFDM) signal, whose individual subcarriers get modulated once it reflects off (passes through) the chest (the hand) of the subject. This way, the signal collected by the receive SDR consists of channel frequency response (CFR) that captures the variation in the blood osmolality due to dehydration. The received raw CFR data is then passed through a handful of machine-learning (ML) classifiers that classify each subject as either hydrated or dehydrated. To train our ML classifiers, we have constructed our custom dataset by collecting data from five Muslim subjects who were fasting during the month of Ramadan. Specifically, we have implemented and tested the following ML classifiers:
${k}$
-nearest neighbor (KNN), support vector machines (SVMs), decision tree (DT), ensemble classifier, and a neural network (NN) classifier. Among all the classifiers, the neural network classifier achieved the best classification accuracy, that is, an accuracy of 93.8% (96.15%) for the proposed chest-based (hand-based) method. Compared to the prior contact-based method where the reported accuracy is 97.83%, our proposed noncontact method provides slightly less accuracy than that reported in the literature for the contact-based method; nevertheless, the advantages of our noncontact dehydration method speak for themselves.
收起
摘要 :
In the phased-array radar signals from each antenna are transmitted at the same carrier frequency, which yields narrowly focused only angle dependent beampattern. In contrast, in the frequency-diverse-array (FDA) radar signals fro...
展开
In the phased-array radar signals from each antenna are transmitted at the same carrier frequency, which yields narrowly focused only angle dependent beampattern. In contrast, in the frequency-diverse-array (FDA) radar signals from antenna array are generally transmitted at linearly increasing frequencies that yields range, time, and angle dependent beampattern. Reported literature on FDA radar missed the contribution of path-differences in the signal model due to the antenna array elements, which may lead to misleading results. In this work, incorporating missed path-differences, the signal model of FDA radar is reanalyzed for reliable results. Moreover, a novel low complexity algorithm based on discrete-Fourier-transform (DFT) is proposed for the desired beampattern. In contrast to the standard FDA radar's “S” shaped beampattern, the beampattern of the proposed algorithm changes linearly with range and time. Furthermore, spatial exploration of FDA radar is derived and it is found that it depends on the frequency-offset and pulse-duration. Finally, the bound on the product of frequency offset and pulse duration is derived. Simulation results compare the performance of our proposed algorithm with the existing ones and show the superiority of our proposed algorithm.
收起
摘要 :
There is a rapid increase in the use of affordable electronic devices and human–machine interfaces (HMIs) with short serviceable life in almost every aspect of our lives. It is estimated that the waste electrical and electronic e...
展开
There is a rapid increase in the use of affordable electronic devices and human–machine interfaces (HMIs) with short serviceable life in almost every aspect of our lives. It is estimated that the waste electrical and electronic equipment (WEEE) and electronic waste (e-waste) generated in year 2021 was 57.5 million metric tons (Mt) and it is expected that the production of e-waste will increase to 110 Mt by the end of 2050. To mitigate these wastes, green HMIs are required which can be customized for multiple applications and can be recycled or disposed of with minimal environmental impact. This work presents customizable graphite-on-paper (GOP)-based keypad consists of interdigitated capacitive (IDC) touch sensors is demonstrated as HMIs to interact with different electronic and media applications wirelessly. The GOP keypads are fabricated through facile and green fabrication process by direct writing of graphite on flexible paper substrate. The GOP keypads can be fabricated in a home setting as the required materials are readily available, i.e., paper, pencils, and Arduino. The GOP keypads can be easily disposed of or recycled at the end of its life or requirement due to the employment of biodegradable materials like paper and graphite. The IDC touch sensors are optimized by analyzing the number of electrode fingers, finger’s width, finger’s overlap length, and spacing between the electrode fingers. The same GOP keypad is customized to interact with different electronic and media applications wirelessly, i.e., laptop cursor navigation, calculator app on mobile, numeric keypad, etc. The customizable GOP keypads have potential to be used as green wireless HMIs to enforce a circular economy by mitigating electronic and plastic waste, which leads to the vision of a sustainable and green world.
收起
摘要 :
In this era of post-COVID-19, humans are psychologically restricted to interact less with other humans. According to the world health organization (WHO), there are many scenarios where human interactions cause severe multiplicatio...
展开
In this era of post-COVID-19, humans are psychologically restricted to interact less with other humans. According to the world health organization (WHO), there are many scenarios where human interactions cause severe multiplication of viruses from human to human and spread worldwide. Most healthcare systems shifted to isolation during the pandemic and a very restricted work environment. Investigations were done to overcome the remedy, and the researcher developed different techniques and recommended solutions. Telepresence robot was the solution achieved by all industries to continue their operations but with almost zero physical interaction with other humans. It played a vital role in this perspective to help humans to perform daily routine tasks. Healthcare workers can use telepresence robots to interact with patients who visit the healthcare center for initial diagnosis for better healthcare system performance without direct interaction. The presented paper aims to compare different telepresence robots and their different controlling techniques to perform the needful in the respective scenario of healthcare environments. This paper comprehensively analyzes and reviews the applications of presented techniques to control different telepresence robots. However, our feature-wise analysis also points to specific technical, appropriate, and ethical challenges that remain to be solved. The proposed investigation summarizes the need for further multifaceted research on the design and impact of a telepresence robot for healthcare centers, building on new perceptions during the COVID-19 pandemic.
收起
摘要 :
This letter considers the blind separation of convolutive mixtures in a multi-in-multi-out (MIMO) communication system. Multiple source signals are transmitted simultaneously over a shared communication medium (modeled as linear c...
展开
This letter considers the blind separation of convolutive mixtures in a multi-in-multi-out (MIMO) communication system. Multiple source signals are transmitted simultaneously over a shared communication medium (modeled as linear convolutive channels) to multiple receivers. We recast the joint recovery of the source signals, and the channel impulse responses as a block-rank-one matrix recovery problem, which can be effectively solved using a convex program. Our numerical experiments show that the proposed convex program yields exact recovery of the source signals when they are members of known generic subspaces. Moreover, the numerics also show that the successful recovery is achieved in blind MIMO with the number of measurements that scale roughly optimally with the number of unknowns. We discuss our results in the context of an application in blind MIMO wireless communications, where coding the transmitted messages results in exact blind separation at the receiver array.
收起
摘要 :
Free-space optical (FSO) communication can be seen as a promising technology for point-to-point and back-hauling links in the next generation wireless networks (5G and beyond) where cell size may shrink to a few hundred meters. In...
展开
Free-space optical (FSO) communication can be seen as a promising technology for point-to-point and back-hauling links in the next generation wireless networks (5G and beyond) where cell size may shrink to a few hundred meters. In this work, we have experimentally investigated the laser beam propagation for FSO link under atmospheric turbulence and fog conditions. A controlled atmospheric environment chamber is designed to perform experiments under varying channel conditions. For fog attenuation, we have proposed an empirical model as a function of visibility against the measured average values, for visibility range of $0\leq V \leq1000$ m. For atmospheric turbulence, we report the measured values of the refractive index structure parameter $C_{n}^{2}$ . The measured $C_{n}^{2}$ is used to calculate the atmospheric coherence width along the propagation distance. This work would help in the design optimization of practical FSO links under adverse conditions like fog and atmospheric turbulence.
收起
摘要 :
Saturated ferrites exhibit microwave and millimeter-wave absorption because they consist of nanomagnetic harmonic oscillators. The absorption frequency and linewidth are dictated by the strength and range of interactions between t...
展开
Saturated ferrites exhibit microwave and millimeter-wave absorption because they consist of nanomagnetic harmonic oscillators. The absorption frequency and linewidth are dictated by the strength and range of interactions between the magnetic dipoles. The forced orientation of magnetic dipoles along the magnetic bias results in Zeeman splitting in the energy levels. The incoming electromagnetic wave can excite dipoles to transition between these energy levels. In order to investigate the effects of input frequency and Gilbert damping constant on the electromagnetic properties, a magnetic transmission line model is presented for a saturated ferrite. The enhanced power loss during ferromagnetic resonance is contributed to the strong spike of longitudinal magnetic admittance and transverse magnetic impedance.
收起
