Understanding public outlook in healthcare management is important in the study of the various diseases. With respect to vaccinations, which play a major role in combating vaccine-preventable diseases, the study on their acceptance or rejection by the public becomes useful. In particular to the influenza vaccine, studies on the public opinion and views is ongoing. Social media platforms like Twitter help us to leverage thoughts and attitudes related to the flu vaccine. The data set used for our analysis contained tweets related to vaccines which were collected using vaccine-related keywords over a period of twelve months from February, 2018 to January, 2019. Out of these tweets, we filtered out the tweets specific to the flu vaccine and generated our corpus for further study. By using Latent Dirichlet Allocation (LDA), we identified eighteen topics comprising six major themes which best represented our corpus. In this paper, we discuss these six themes and subsequently analyze the trend observed in these themes over a period of twelve months. The themes identified covered various aspects related to the flu vaccine. Among the six major themes, four showed a distinctive temporal trend with respect to the annual flu season.

Low-power consumption of orientation estimation using low-cost inertial sensors are crucial for all the applications which are resource constrained critically. This paper presents a novel Lightweight quaternion-based Extended Kalman Filter (LEKF) for orientation estimation for magnetic, angular rate and gravity (MARG) sensors. In this filter, with employing the quaternion kinematic equation as the process model, we derived a simplified measurement model to create the lightweight system model for Kalman filtering, where the measurement model works efficiently and the involved computation of measurement model is reduced. It’s later proved that the proposed filter saves time consumption. Further, due to that no linearization is involved for the proposed measurement model, the good performance would be guaranteed in theory. For the experiments, a commercial sensor for data collection and an optical system to provide reference measurements of orientation, namely Vicon, are utilized to investigate the performance of the proposed filter. Evaluation for different application scenarios are considered, which primarily includes human motion capture and the drone application. Results indicate that the proposed filter provides reliable performance for both applications. What’s more, the comparison experiment shows that the proposed filter provides better performance in terms of either attitude estimation accu- racy or computational time.

Classical reality is described in terms of objects and things and their mutual relationships. On the other hand, in the case of quantum reality, the collapse of the state in an interaction assigns a unique position to the observer. These two disparate views are based on different logics of representation. In this paper, we first summarize the early evolution of these ideas and then go beyond the implicit dependence of the quantum theory framework on the mathematical apparatus of calculus and vector spaces, by delving one layer deeper to an information-theoretic understanding of symbol representation. We examine some epistemic implications of the fact that, mathematically, e-symbol representation is optimal and 3 symbols are more efficient that 2 symbols, and this optimality leads to the idea that space itself is e-dimensional, and not 3-dimensional. We also discuss the principle of veiled nonlocality as a way to understand the split between the observer and the physical process.

With advancements in PET technology, scanners with a very good time-of-flight (TOF) resolution became available. In addition, scanners with long axial extent are now commercialized. Although raw data sizes increase significantly with such scanners, good TOF resolution allows substantial data compression without any loss of spatial resolution: for example, the histo-projections with relatively coarse sampling in the TOF direction in the Siemens Biograph Vision and Vision Quadra PET/CT scanners. The patient motion during the scan is unavoidable. The pattern caused by breathing may result in a relatively large displacement of organs and the consequent blurring of clinically relevant features in regions affected by the motion. As was shown in our previous work, non-rigid motion correction can be performed in the quasi-image space of histo-projections. The TOF locality property can be used to locally perform motion correction; that is, the approximation of motion as locally rigid on a scale of TOF resolution. In this work, we investigate motion estimation in the TOF data space from histo-images by histogramming the data into a 3D array consistent (in geometry and size) with the reconstruction image. The histo-image estimated motion is then used in histo-projections motion correction. Initial results using an XCAT digital phantom showed that the presented methodology accommodates for changes in non-rigid body movements for a typical pattern of patient motion. The patient scan on newly developed Biograph Vision Quadra PET/CT scanner was used in validation of presented motion correction.

To appear in IEEE Transactions on Industrial Informatics Abstract: Although the skills of robot manipulators are becoming technically more complex, the unprecedented cost-effective access to recently unveiled intelligent robots has the potential to unleash as yet unimagined automation capabilities. A key technology behind this opportunity for companies to gain a competitive edge through an informed and intelligent robotized automation is the robotic digital twin (RDT). As such, the RDT will be instrumental in mirroring targeted properties of a physical robot to obtain a digital sibling flexibly harnessed in virtual testbeds to understand, predict, and shape the robot performance. However, these objectives remain challenging to well-established simulators. This is because the architectural and functional capabilities they support are not sufficiently in-line with ever-growing and varying demands for agile and cost-efficient manipulations. As a consequence, robot stakeholders can hardly use RDTs to unlock opportunities and meet needs from prospective markets. This paper contributes to addressing this gap. We introduce a novel concept for the development of a RDT that helps create and add value to current and future robotized cyber-physical applications. Hereinafter referred to as the value-driven RDT (vdRDT), it systematically captures the robot dynamics and purposefully farms data, about which its services reason to facilitate insight and deliver capabilities and benefits to stakeholders. Experiment results show that vdRDTs enlarge the scope of, adapt to, and revitalize robotized applications carried out in different fields.

Wu-Chieu proposed an enhanced remote user authentication scheme to improve the security of a user-friendly remote user authentication scheme with smart cards. However, we demonstrate that their scheme is vulnerable and susceptible to the attacks and can easily be cryptanalyzed. Their scheme performs only unilateral authentication (only client authentication) and there is no mutual authentication between user and remote system, so their scheme suscepts from the server spoofing attack. Furthermore, their scheme is slower in detecting the wrong input-password, and users cannot change their passwords. This paper proposes an efficient and secure remote authentication scheme to solve the problems found in Wu-Chieu’s scheme. In addition, the computational costs and efficiency of the proposed scheme is better than other related published schemes.

A document by Mohammad Rowshan . Click on the document to view its contents.

This paper proposes orthogonal time sequency multiplexing (OTSM), a novel single carrier modulation scheme based on the well known Walsh-Hadamard transform (WHT) combined with row-column interleaving, and zero padding (ZP) between blocks in the time-domain. The information symbols in OTSM are multiplexed in the delay and sequency domain using a cascade of time-division and Walsh-Hadamard (sequency) multiplexing. By using the WHT for transmission and reception, the modulation and demodulation steps do not require any complex multiplications. We then propose two low-complexity detectors: (i) a simpler non-iterative detector based on a single tap minimum mean square time-frequency domain equalizer and (ii) an iterative time-domain detector. We demonstrate, via numerical simulations, that the proposed modulation scheme offers high performance gains over orthogonal frequency division multiplexing (OFDM) and exhibits the same performance of orthogonal time frequency space (OTFS) modulation, but with lower complexity. In proposing OTSM, along with simple detection schemes, we offer the lowest complexity solution to achieving reliable communication in high mobility wireless channels, as compared to the available schemes published so far in the literature.

This manuscript was published at 08.10.2021 by the IEEE Transactions on Magnetics. Regarding Mr. Sivo’s Email, the accepted version of the manuscript is now uploaded which also includes the corresponding DOI.

A document by Vijayashekhar S S . Click on the document to view its contents.

The year 2020 has witnessed unprecedented levels of demand for COVID-19 medical equipment and supplies. However, most of today’s systems, methods, and technologies leveraged for handling the forward supply chain of COVID-19 medical equipment and the waste that results from them after usage are inefficient. They fall short in providing traceability, reliability, operational transparency, security, and trust features. Also, they are centralized that can cause a single point of failure problem. In this paper, we propose a decentralized blockchain-based solution to automate forward supply chain processes for the COVID-19 medical equipment and enable information exchange among all the stakeholders involved in their waste management in a manner that is fully secure, transparent, traceable, and trustworthy. We integrate the Ethereum blockchain with decentralized storage of interplanetary file systems (IPFS) to securely fetch, store, and share the data related to the forward supply chain of COVID-19 medical equipment and their waste management. We develop algorithms to define interaction rules regarding COVID-19 waste handling and penalties to be imposed on the stakeholders in case of violations. We present system design along with its full implementation details. We evaluate the performance of the proposed solution using cost analysis to show its affordability. We present the security analysis to verify the reliability of the smart contracts, and discuss our solution from the generalization and applicability point of view. Furthermore, we outline the limitations of our solution in form of open challenges that can act as future research directions. We make our smart contracts code publicly available on GitHub.

We investigate a new type of electromagnetic meta-materials (MTMs), which we dub Proca MTMs, constituting an interesting medium behaving like a “relativistic material” for potential use in electromagnetic applications. It is rigorously proved using a field-theoretic approach that Maxwell theory inside certain classes of nonlocal metamaterials is equivalent to Maxwell-Proca theory in vacuum, where in the latter photons acquire a nonzero mass (massive electromagnetism.) It turns out that the key to the operation of Proca MTM is nonlocality (here spatial dispersion since the Proca MTM is homogeneous), and hence Proca MTMs represent an important example of the more general family of nonlocal MTMs. Our analysis involves multiphysics aspects, utilizing concepts and methods taken from classical electromagnetism, special relativity, quantum theory, electromagnetic materials, and antenna theory. Extensive discussion of the physics, computational methods, and design parameters of Proca MTMs is provided to further understand the nature of massive electromagnetism in nonlocal MTMs. Proca waves carry an additional polarization degree of freedom and each wave appears to behave like a single mode with two transverse components and one longitudinal. This opens the door for applications in wireless communications and other fields where information could be encoded in polarization. As a concrete application, we develop the main ingredients of Proca antennas as an example of the emerging technology of nonlocal antennas, where we establish that a single Proca dipole possesses a perfect isotropic radiation pattern, a radical departure from conventional local antennas (radiators in vacuum and temporally dispersive media) where such radiation characteristics is impossible. Moreover, the new connection between electromagnetic theory in some nonlocal MTMs and Maxwell-Proca theory allows the use of relativistic techniques developed in the latter in order to efficiently perform calculations like field quantization in nonlocal domains which would be very difficult to perform otherwise.

This paper deals with time and frequency synchronization in LoRa system based on the preamble symbols. A thorough analysis of the maximum likelihood (ML) estimator of the delay (time offset) and the frequency offset shows that the resulting cost function is not concave. As a consequence the a priori solution to the maximization problem consists in exhaustively searching over all the possible values of both the delay and the frequency offset. Furthermore, it is shown that these parameters are intertwined and therefore they must be jointly estimated, leading to an extremely complex solution. Alternatively, we show that it is possible to recover the concavity of the cost function, from which we suggest a low-complexity synchronization algorithm, whose steps are described in detail. Simulations results show that the suggested method reaches the same performance as the ML exhaustive search, while the complexity is drastically reduced, allowing for a real-time implementation of a LoRa receiver.

Determining the number of groups or dimension of a feature space related to an initial dataset projected to null-space of the Laplace-Beltrami-type operators is a fundamental problem of applications exploiting a spectral clustering techniques. This paper theoretically focuses on generalizing and providing minor comments to a previous work by Bruneau et al., who proposed modification of the Bartlett test that is commonly used in the principal component analysis, to estimate the number of groups related to normalized spectral clustering approaches. The generalization is based on a relation between the distributions of the spectrum associated with a covariance matrix and graph Laplacian, which allows us to use the modified Bartlett test for unnormalized spectral clustering as well. Other comments follow previous works by Lawley and James, which allow us testing subsets of eigenvalues by involving likelihood ratio statistic and linkage factors. Solving issues arising from limits of floating-point arithmetic are demonstrated on benchmarks employing spectral clustering for $2$-phase volumetric image segmentation. On a same problem, analysing spectral clustering in divide-merge settings is presented.

This paper studies a class of stochastic and time-varying Gaussian intersymbol interference (ISI) channels. The $i^{th}$ channel tap during time slot $t$ is uniformly distributed over an interval of centre $c_i$ and radius $ r_{i}$. The array of channel taps is independent along both $t$ and $i$. The channel state information is unavailable at both the transmitter and the receiver. Lower and upper bounds are derived on the White-Gaussian-Input (WGI) capacity $C_{{WGI}$ for arbitrary values of the radii $ r_i$. It is shown that $C_{WGI}$ does not scale with the average input power. The proposed lower bound is achieved by a joint-typicality decoder that is tuned to a set of candidates for the channel matrix. This set forms a net that covers the range of the random channel matrix and its resolution is optimized in order to yield the largest achievable rate. Tools in matrix analysis such as Weyl’s inequality on perturbation of eigenvalues of symmetric matrices are used in order to analyze the probability of error.

A document by Doaa Ahmed . Click on the document to view its contents.

Water Distribution Systems (WDS) are critical infrastructures that deliver potable water to residential areas. Water quality monitoring is one of the requirements for utility managers to ensure the health of the water. However, it is challenging to access all parts of the WDS since they are long and comprise different configurations. In this paper, we propose a size-adaptable in-pipe robot so-called “SmartCrawler”. We develop two-phase control algorithm that enables reliable motion in different configurations of pipelines. The controller in phase 1 stabilizes the robot in the straight paths and tracks the desired velocity with high-level linear quadratic regulator (LQR) and low-level proportional-integral-derivative (PID) based controllers. The controller in phase 2 enables the robot to have reliable change of direction in the non-straight paths. The performance of the two-phase controller is evaluated with experimental and simulation results. Wireless underground communication is a challenging task for underground applications. To facilitate wireless communication, we propose an active radio frequency identification (RFID) based communication working in 434MHz carrier frequency and evaluate its performance with experimental results. At the end of this work, we design the printed circuit board (PCB) for the SmartCrawler. The simulation and the experimental results prove the proposed robotic system can be used for in-pipe missions where wireless communication is needed to communicate with the robot during operation.

A document by Doaa Ahmed . Click on the document to view its contents.