Miracle-dz/UniFAR-FTUs huggingface dataset:
On the Security of the Wireless Electric Vehicle Charging Communication

The adoption of fully Electric Vehicles (EVs) is happening at a rapid pace. To make the charging as fast and convenient as possible, new charging approaches are developed constantly. One such approach is wireless charging, also known as Wireless Power Transfer (WPT). Instead of charging an EV via a charging cable, the battery is charged wirelessly. For safety and efficiency reasons, the vehicle and the charging station continuously exchange critical information about the charging process. This includes, e.g., the maximum voltage and current, battery temperature, and State of Charge (SoC). Since there is no physical connection between the vehicle and the charging station, this necessary control communication has to be implemented as a wireless connection. However, if the communication is interrupted, the charging process is aborted for safety reasons. In this paper, we analyze the attack surface of EV charging standards that use such a wireless control communication. More specifically, we discuss potential wireless attacks that can violate the availability and analyze the implemented security features of a real-world wireless charging station that has already been deployed. We found that the tested charging station does not implement even simple security measures, such as IEEE 802.11w, that can protect the communication from denial-of-service attacks. Finally, we discuss potential countermeasures, and give recommendations to improve the security and increase the resilience of wireless charging.
Design of the AC Filter for Two-Level Converter Operating in IT Grids

The paper presents the procedure of selecting the parameters of a grid filter with a common mode choke. The document is organized as a case study, where an example is a multi-converter system supplied from a 500 V three-phase IT grid. Due to the same topology of AC/DC and DC/AC component converters, it is possible to use the same filter for both converters. Particular attention is paid to the problems of the common mode choke, especially the issue of the core saturation effect. The proposed filter has been verified by laboratory tests.
Modulation and Control Schemes of Modular Three Phase FCC-CSC for High Power Applications

The AC-type flying capacitor (FC) technique instead of device series connection is a promising way to increase the system voltage rating for current source converter (CSC) based high-power applications. Improved DC-link voltage with low dv/dt and reduced common-mode voltage (CMV) can be achieved with proper modulation and FC voltage control. Parallel connection of power converters, on the other hand, is a popular choice to increase the system's current rating for higher power applications. Moreover, supervisor harmonic performance can be achieved through interleaving operation with reduced need for passive filters. Modular FCC-CSC structure can combine these merits to achieve a higher power rating, and better DC- and AC-side quality. More importantly, the improved AC quality can in turn help the regulation of FC voltage. This paper discussed the modulation and control schemes of modular three-phase FCC-CSC, the space vector modulation (SVM) based FC voltage control, and DC-link current balance strategies are proposed. Experiment results verified the effectiveness of the proposed methods.
Network traffic classification based on periodic behavior detection

Even though encryption hides the content of communication from network monitoring and security systems, this paper shows a feasible way to retrieve useful information about the observed traffic. The paper deals with detection of periodic behavioral patterns of the communication that can be detected using time series created from network traffic by autocorrelation function and Lomb-Scargle periodogram. The revealed characteristics of the periodic behavior can be further exploited to recognize particular applications. We have experimented with the created dataset of 61 classes, and trained a machine learning classifier based on XGBoost that performed the best in our experiments, reaching 90% F1-score.
Influence of Frequency Fluctuations on Protection of AC Area of Flexible HVDC Transmission

Affected by the rapid control of power electronic equipment, the flexible DC transmission system is prone to frequency fluctuations and disturbance signal, which will bring deviation to the electrical quantity measurement and cause the protection system malfunction. The influence of frequency fluctuations on Fourier algorithm in flexible DC transmission is explored, and the corresponding protection simulation model is built based on the principles of different protections. It can be seen that frequency fluctuations will produce varying degrees of interference to the action range and sensitivity of power line protection. A corresponding algorithm based on amplitude and phase calculation during frequency fluctuations in specific line protection is proposed, and a logic judgment method is designed to comprehensively judge the changes of differential current, AC voltage and frequency to determine the operating state of the system to improve reliability. Considering the influence of frequency fluctuation on the protection, by monitoring multiple electrical parameters in the AC area of the flexible HVDC transmission system, the logic judgment device comprehensively judges the changes of differential current, AC-voltage and frequency to determine the operation state of the system. Simulation results show that this method can reduce the impact of frequency fluctuations and interference signals on line protection, and explore a power grid protection method suitable for the dynamic change of frequency, which is of great practical value to ensure the safe and stable operation of flexible DC transmission network.
Girls Wellbeing: Anxiety And Mathematical Achievement At The End Of Primary School

The aim was to determine whether there is a relationship between anxiety and mathematical performance in sixth grade primary school students, and if gender differences exist. Mathematics anxiety is a type of anxiety that affects this specific academic area or it is triggered by it. Studies have shown that students from the beginning of adolescence show mathematics anxiety and it increases as they progress through an academic environment. There is evidence to suggest that two important factors play a role in mathematics anxiety: the educational level and gender. There is consistent evidence that girls tend to be more affected by it than boys, but this has not been studied in primary school. 149 sixth grade students (mean age 140.5 months) from four schools in two Peruvian cities participated in two assessments, one that aimed to assess their level of mathematical anxiety and one that aimed to assessed their mathematical achievement. Results revealed that although there is no relation between mathematical anxiety and mathematical performance in sixth grade students, there are gender differences. Females $(\mathrm{n}=72)$ have an almost significant relationship $(\mathrm{r}=\text{-}.227, \mathrm{p}=0.56)$. Presenting a lower mean in mathematics achievement compared to their male counterpart $(\bar{\mathrm{x}}=14.05$ and 15.71 respectively) and higher anxiety $(\bar{\mathrm{x}}=49.92$ and 42.64 respectively). This evidence has theoretical and practical implications in education, supporting girls' anxiety, as this could have a negative impact on their academic performance and wellbeing.
Topology and Control of Repetitive Pulsed Power Supply with Interleaved Output

In the repetitive-frequency pulsed power application, the high-voltage capacitor is usually used as the terminal energy buffer to reduce the impact of the pulsed loads on the power grid. The output voltage is repeatedly charged to the set value through the capacitor charge power supply (CCPS). However, the capacitor charging process is highly nonlinear. There is a sudden change of the power caused by the disconnection between the CCPS and the output capacitor during the discharge, which seriously affects the waveform quality of the power grid. A new capacitor charging topology with interleaved output is proposed in this paper, which could fully eliminate the sudden change of the output power, and achieve up to twice of the repetitive frequency. With constant power control, the proposed topology renders the pulsed power supply appear like the linear load, which contributes to the unity power factor of the front-end power factor correction stage. The correctness and effectiveness of the proposed scheme are validated through simulation.
Improvements to the VSM current controller for better grid performance

Output current control is widely used as the innermost control loop of inverters, in particular virtual synchronous machines (VSM). The realization of this controller is commonly based on a PI controller working in a synchronous reference frame. The controller should mitigate the grid currents distortion and the unsteady amplitudes caused by A/D converter imperfections, measurement errors and processing delays. The elimination of any DC component in the output currents is another relevant demand. The literature indicates that the current controller parameters are usually chosen by experimental tuning. In this paper, we propose a fast current controller design procedure that provides compensation for the processing delays and eliminates the DC components of the grid-side currents. We propose to control also the zero component of the output currents (which helps in an unbalanced grid). We present the performance of the novel features of our current controller through a series of simulations, comparing it to the performance of the same controller without the proposed additional features. In addition, we compare our new current controller's design with one proposed in the literature. The results show that the new current controller leads to a better performance of the VSM in terms of output active power oscillations and stability.
An Adaptive TDMA Approach for Improving Reliability and Performance in WBAN under Heterogeneous Traffic and Interference

Medium Access Control (MAC) based on Time Division Multiple Access (TDMA) sublayer approaches have been proposed to improve Wireless Body Area Networks (WBAN) reliability and efficiency. These approaches inadequately deal with device heterogeneity and the message traffic dynamics in WBANs. We propose an adaptive policy TDMA-based MAC protocol. To improve policy communication between devices, each one receive time slots for transmission, considering their band-width and communication channel interference. Our approach simulations results show significant reliability and performance compared to IEEE 802.15. 4, IEEE 802.15. 6, and DSBS (Dynamic Scheduling Based on Sleeping Slots) protocols. The protocol decreased message loss while maintaining low power consumption and low latency in experiment simulation scenarios.
Hypergraph Laplacian Diffusion Model for Predicting Resting Brain Functional Connectivity from Structural Connectivity

The relationship between the structure and function of the human brain is of immense importance in neuroscience and cognitive science, but little is known about how the brain structure shapes the function. Recent studies have shown that the graph Laplacian of structural connectivity (SC) plays an important role in generating functional connectivity (FC) in the resting state. However, the graph Laplacian can only simulate part of function due to the sparseness of the structural connection matrix. Additionally, it fails to model the negative functional correlations since it ignores the connection type information (excitatory or inhibitory) between brain regions. In this paper, we generalize the graph Laplacian to the hypergraph Laplacian, which can build relations between structurally unconnected brain regions, thus better results are obtained. Further, in order to simulate the negative correlations, we extract a sign matrix from the FC matrices of the first two subjects and then incorporate it into the model. We test the model on one empirical connectome dataset with 246 regions of interest (ROI) and the results show that the proposed hypergraph Laplacian model can describe FC with more accuracy than the graph Laplacian model.
Matching-network boosting enabling reconfigurable pMUTs for IoT sensor node applications

This paper presents an architectural technique to improve the performance of pMUT-based communication links and, at the same time, enable pMUTs' frequency reconfigurability. By using a high-quality factor ($Q$) MEMS resonator as matching network (MN), we show that a substantial increase in a pMUT-based underwater receiver (Rx) sensitivity can be achieved at the cost of a reduced bandwidth. The out-of-band boosted response is significantly higher than what is achieved by the standalone pMUTs sensitivity. This means that the system peak sensitivity is set by the MN resonance, and it is independent from the pMUTs center frequency. Therefore, we show that by multiplexing different MNs it is possible to reconfigure pMUTs' operation. Moreover, we demonstrate that, by loading the MEMS resonator MN (MRMN) with different commercial off-the-shelf (COTS) resistors, we can tune the trade-off between sensitivity and bandwidth (BW).
Boosted Backstepping Control by Disturbance Observer for Reconfigurable Quadrotor

The main objective of this paper is to control and ensure good trajectory tracking of a reconfigurable quadrotor exposed to external perturbations. This control law is integrated with the disturbance observer and based on the finite-time Lyapunov stability theory. First, a dynamic model of the studied system is developed. The latter takes into consideration the variation of the Center of Gravity (CoG), the inertia, and the allocation matrix. Then, the theoretical basis of backstepping control integrated with disturbance observer is presented. The observer estimates the perturbations online and compensates them in the internal loop that contains the attitude and the position backstepping controllers. Finally, simulation results are provided to illustrate the performance of this controller. Overall, the findings show that the proposed control technique outperforms in terms of accuracy and robustness.
A Novel UWB Printed Monopole Antenna with Enhanced Frequency Bandwidth

In this work, an ultra wideband monopole antenna with an extended frequency bandwidth has been developed. This mainly consists on introducing defects with suitable shapes and locations to an original circular antenna that resulted in a significant bandwidth enhancement. A prototype of the obtained structure has been fabricated and its reflection coefficient measured where a good agreement is noticed between simulated and experimental results. The antenna simulated bandwidth [2.150-15.253 GHz] makes it suitable for the several wireless applications operating in this frequency interval.
Selective Hardening of CNNs based on Layer Vulnerability Estimation

There is an increasing interest in employing Convolutional Neural Networks (CNNs) in safety-critical application fields. In such scenarios, it is vital to ensure that the application fulfills the reliability requirements expressed by customers and design standards. On the other hand, given the CNNs extremely high computational requirements, it is also paramount to achieve high performance. To meet both reliability and performance requirements, partial and selective replication of the layers of the CNN can be applied. In this paper, we identify the most critical layers of a CNN in terms of vulnerability to fault and selectively duplicate them to achieve a target reliability vs. execution time trade-off. To this end we perform a design space exploration to identify layers to be duplicated. Results on the application of the proposed approach to four case study CNNs are reported.
A 0.7-2.5GHz NB-loT/GNSS/BLE Hybrid PLL with PA Pulling Mitigation and Out-of-Band Phase Noise Reduction

A 0.7-2.5GHz NB-IoT/GNSS/BLE hybrid PLL with a single D/VCO is implemented in 28nm CMOS. With careful frequency planning, the PA pulling effect is mitigated by using a multi-mode divider chain. A divider-by-2.5 relaxes the tuning range requirement of the D/VCO and mitigates the PA pulling for NB-IoT HB band, while a divider-by-6 is designed for NB-IoT LB. With an 8-tap FIR filtering method, a wideband fractional-N PLL is designed without increasing the out-of-band phase noise. The proposed PLL consumes the maximum 4.7mW with 0.9V supply. Experimental results show that the PLL meets the phase noise and spur requirements of the NB-IoT/GNSS/BLE standards.
A Deep Learning Application to the 2004 Flooding of the City of Gonaïves in Haiti

In this paper, a deep learning network is considered to study the impact of the flooding on the city of Gonaives that occurred on 18 September 2004. Satellite images collected before and after the disaster are segmented then partitioned into 2 and 3 classes and later used to train and test the deep learning network, to estimate the damage that was inflicted upon the land topography and infrastructures of the city. Experiments conducted on the data revealed high performance of the network to identify areas buried in muddy water and regions of the city that did not suffer any damages. Data augmentation scenarios carried out on the training set translated into higher performance of the network on the test data than the result achieved when it was trained solely on the original images. The practicality of the deep learning to locate areas that were severely affected by the flood and estimate its impact on the residents of the city of Gonaïves is revealed.
Achievable capacity analysis for power domain non-orthogonal multiple access scheme

In this paper, we study the PD-NOMA non-orthogonal power domain multiple access technique for 5th generation wireless networks. This technique provides a solution to the overhead problems of wireless networks that have emerged due to the increase in the number of users. We describe two different power allocation schemes called fixed and fair in the case of two users. We simulated the capacity of a NOMA system using two different schemes based on the total power allocated for transmission. The results of the comparison between the two power allocation schemes show that the best performance is with the fair power allocation.
Study on the Dielectric Recovery Performance of High Voltage SF6 Circuit Breaker

To investigate the dielectric recovery performance of the SF6 circuit breaker after the current zero (CZ), the magneto-hydro-dynamic (MHD) model of arc burning process was established for the structure of a 126 kV auto-expansion switch. Two methods of evaluating the post-arc dielectric recovery strength were established. The fist method is predicting the most likely area of post-arc electric breakdown according to the temperature and pressure distribution. Another method is based on the leader inception criterion. The results about the post-arc breakdown voltage and electrical field distribution is essential for the evaluation of the performance of arc interruption. The simulation results can be used to estimate the possibility of breakdown and arc reburning after CZ. The influence of current value on the strength recovery during the post-arc is studied. It is indicated that higher current is conducive to the post-arc dielectric recovery. The results of this paper are significant for the optimization design of high voltage circuit breaker.
Ultrasonic Characterization of Rat Vagus Nerves using 25 MHz Pulse Reflectometry

In this paper, a rat vagus nerve's (VN) speed of sound was extracted from the pulse-echo voltage responses which were transmitted and received using a spherically focused 25MHz center frequency immersion ultrasonic transducer (UT). Four VNs were extracted following standard lab protocols and a desktop scanning acoustic microscope (SAM), with a 3-axis motorized stage (having 40 µm precision and 12.5 mm travel), was programmed to determine the nerve's orientation, height, and profile after measuring the water's acoustic velocity (AV) using a PHT (pressure humidity temperature) sensor. Before every measurement, the transducer face was automatically placed 12.7 mm away from the specimen's substrate. A spherically focused transducer with high operating frequency was required to achieve sufficient resolution through the nerve's small diameter of ~0.5 mm. Using the specialized SAM, the time of flights corresponding to the first four echoes were captured, and the nerve's acoustic velocity was calculated to be between 1575–1582 m/s. Understanding the VN's acoustic characteristics will be necessary to achieve fascicle specificity using focused ultrasonic neuromodulators. Stimulating only desired VN fascicles with precision and repeatability will allow targeted treatment of illnesses with lesser side effects than current options.
A Fast and Resource-efficient GSOP Implementation for Optical Coherent Receivers

In-phase/quadrature(I/Q) imbalance compensation is an important procedure in optical coherent systems, and the Gram-Schmidt orthogonalization procedure (GSOP) is one of the most widely used compensation algorithms. However, the division and square-root operations consume a lot of hardware resources, limiting the speed of FPGA implementation. This paper proposes a fast and resource-efficient GSOP implementation by converting square-root and division operations into linear fitting. We introduce the Newton iteration method to compensate for the accuracy degradation. The FPGA implementation shows that the throughput of the 128-way-parallel GSOP is up to 100Gbps at the frequency of 392MHz.
A Time-of-Flight (ToF) estimation algorithm for ranging using Silicon-On-Nothing pMUTs

This work presents a novel ToF estimation algorithm using Silicon-on-Nothing (SoN) ScAlN pMUTs based on a unique two-step matched filter with a template signal that was extracted independently from the measured data. This work reports, for the first time, the application of the proposed algorithm for environmental temperature sensing using a pair of pMUTs. Preliminary results reported a mean accuracy of 98.5% for a sensing temperature range of 30 to 126° C, thus, paving the way towards the algorithm's use for temperature sensing using pMUTs. The proposed temperature sensing setup could be extended to measure temperatures as high as 250° C (given the device heat tolerance) and modified for non-contact surface temperature sensing for biomedical applications (i.e. tissue temperature sensing for therapy monitoring).
Effects of tracking beam dimensions on Harmonic Motion Imaging (HMI) with electronic beam steering of focused ultrasound (FUS)

Previous studies from our group have demonstrated successful applications of Harmonic Motion Imaging (HMI) using a single-element focused ultrasound (FUS) transducer and plane wave (PW) imaging. In this paper, a multi-element FUS transducer was used. The effects of tracking beam dimensions on HMI in terms of contrast and CNR were investigated. These new sequences were validated on a tissue-mimicking phantom with embedded cylindrical inclusions, and an in-vivo murine breast tumor model. There were an overall 4.2% and 51.4% increase in contrast and CNR with focused imaging (F/3) compared with the 5-angle plane wave compounding (PWC) sequence for an 8.4-mm inclusion with Young's modulus of 56 kPa within a 5.3-kPa background. Contrast and CNR were not improved as much in the in-vivo murine model with focused imaging; however tumor boundaries were delineated more uniformly with higher transmit focusing. Electronic beam steering of FUS reduced around 4.6-fold data acquisition time without noticeably compromising HMI image quality.