Miracle-dz/UniFAR-FTUs huggingface dataset:
Towards a Green Blockchain: A Review of Consensus Mechanisms and their Energy Consumption

Organizations all over the world are under pressure to reduce their use of non-renewable energy sources and carbon emissions into the atmosphere due to its increasing negative impact on the ongoing climate crisis. Blockchain is a disruptive technology popularised by its use in Bitcoin, which has subsequently been adopted for various use cases. However, recently Blockchain has started attracting negative attention due to its propensity for high energy consumption depending on the adopted consensus mechanism. In this work, we explore the need for green (sustainable) Blockchain by comprehensively reviewing the various existing consensus mechanisms and their energy consumption to present a framework that will contribute towards developing more sustainable and environment friendly Blockchain-enabled systems.
Improved Harmony Search Algorithm and Application in Optimal Scheduling of Hospital Transport AGV

The scheduling efficiency of automatic guided vehicle (AGV) is of great significance for improving the logistics and transportation efficiency of smart hospitals. In this paper, a mathematical model of AGV scheduling for hospital transportation is established based on the objective of the time for multiple AGVs to cooperate with each other to transport all medical materials. An improved harmony search algorithm (IHSA) was proposed by discretizing the algorithm, optimizing the local search process and introducing chaos generation mechanism. The algorithm was applied to the optimal scheduling model of hospital transport AGV, and the performance of the algorithm was evaluated. The results show that the performance of the proposed IHSA is superior to the existing harmonic search algorithm.
A composite antenna with wide circularly polarized beamwidth

A circularly polarized (CP) composite antenna is studied in this article. The antenna unit is composed of a CP curl antenna and a CP omni‐directional antenna with three pairs of tilted parasitic elements. Reasonable agreement between simulation and measurement is obtained. The proposed antenna has a 10‐dB impedance bandwidth (S11 < −10 dB) of 35% and a 3‐dB axial ratio (AR) bandwidth of 20%. The composite antenna and the reference antenna are compared in this article. The composite antenna can obtain a 3‐dB power gain beamwidth of 110° and 3‐dB AR beamwidth of 120°, when compared with those of the reference antenna with 95° and 95°, respectively. The characteristics of the composite antenna are also investigated. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2461–2464, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24594
Physical Layer Security against an Informed Eavesdropper in Underwater Acoustic Channels: Feature Extraction and Quantization

During the Rapid Environmental Picture 2018 (REP18) sea trial, two underwater acoustic nodes (Alice and Bob) exchanged 897 channel probes over different ranges and environmental conditions. In this short paper, Alice and Bob independently process their received probes offline with the aim to generate a cryptographic key based on Physical Layer Security (PLS). Using their estimated Channel Impulse Responses (CIRs), they compute and quantize four pre-agreed channel features. Eve is a simulated eavesdropper who is aware of the PLS algorithm, the 3D positions of Alice and Bob and the acoustic properties of the environment. Eve uses the de facto standard Bellhop acoustic simulator to predict the bi-directional CIRs between Alice and Bob and compute her own quantized features. We calculate the Bit Disagreement Ratio (BDR), which is a function of the number of disagreeing bits between a pair of nodes. Our results confirm that the proposed features are robust enough to yield a lower BDR between Alice and Bob than that for Eve. The BDR impact on reconciliation and secret key generation is studied in a subsequent paper [1].
Space-vector State Dynamic Model of the Synchronous Reluctance Motor Considering Self, Cross-Saturation and Iron Losses

This paper proposes a space-vector dynamic model of the Synchronous Reluctance Motor (SynRM) including both self-saturation, cross-saturation effects, and iron losses expressed in state form, where the magnetizing current has been selected as a state variable. The proposed dynamic model is based on an original function between the stator flux and the magnetizing current components, improving a previously developed magnetic model. Additionally, the proposed model includes, besides the magnetic saturation, also iron losses. The proposed model requires 11 coefficients, among which 6 describe the self-saturation on both axes and 5 describe the cross-saturation. Starting from the definition of a proper co-energy variation function, both the static and dynamic inductances expressions have been analytically developed, so that the reciprocity condition for the cross-saturation is satisfied. This paper presents also a technique for the estimation of the parameters of the magnetic model and also the resistance describing the iron losses. This technique is based on the minimization of a suitably defined error function which includes the difference between the measured and estimated fluxes. The proposed parameter estimation technique has been tested in both numerical simulation and experimentally on a suitably developed test set-up and the proposed model has been thus validated experimentally
Photonically assisted generation of continuous arbitrary millimetre electromagnetic waveforms

A novel optical-to-electrical technique for the generation of continuous periodic arbitrarily shaped millimetre-wave electromagnetic waveforms at centre frequencies of 50 GHz is demonstrated. Tailored optical pulse sequences from a novel direct space-to-time pulse shaper driving a high-speed photodiode enable generation of arbitrary phase- and frequency-modulated waveforms on a cycle-by-cycle basis.
Optimized Design and Multiphysics Analysis of a Ka-Band Stacked Antenna for CubeSat Applications

Nowadays, the use of CubeSats for telecommunications and interplanetary missions is ever-increasing, thanks to their appealing low-cost character, as well as the space environment, which poses challenging multiphysics constraints on the antenna design. In this framework, the use of Ka-band for communication is explored. We present the design of a stacked patch antenna working across the down- and uplink Ka-bands. Materials and geometry of the radiator have been selected by accounting for the trade-off between electromagnetic, thermal and mechanical requirements. The design of the antenna is performed with a particle swarm optimization algorithm developed to control the bandwidth and matching. A bandwidth of 5.53@33.185 GHz has been obtained, with a gain around 8 dB. Furthermore, a multiphysics thermal analysis is performed to verify the operational stability of the optimized array, mounted on a 1 U satellite, in a case-study mission. The temperature patterns in the array are evaluated during the orbital period, and the influence of the operative temperature on the antenna responses and gain was considered. We found that the thermal loads can affect the antenna matching. However, thanks to the optimized design, the proposed stacked antenna can operate from −100 $^{\circ }$C to 100 $^{\circ }$C, with an almost constant gain. Finally, following a damage-tolerant approach, the level of mechanical deformation, which could be induced on the communication system, was studied. The stress analysis reveals that the stacked geometry can be used in a space mission. From the investigation of the strain and displacement field, we found a negligible impact on the antenna performance.
Input-Output Feedback Linearization Control with On-Line Inductances Estimation of Synchronous Reluctance Motors

This paper proposes an adaptive input-output Feedback Linearization (FL) techniques for Synchronous Reluctance Motor (SynRM) drives, taking into consideration the iron losses. As a main original content, this work proposes a control law based on a new dynamic model of the SynRM including iron losses as well as the on-line estimation of the static inductances. The on-line estimation of the SynRM static inductances permits to inherently take into consideration the magnetic saturation phenomena occuring on both axes. The estimation law is obtained thanks to a Lyapunov-based analysis and thus the stability of the entire control system, including the estimation algorithm, is intrinsically guaranteed. The proposed adaptive FL control improves formerly developed non linear controllers, characterized either by disregarding the saturation phenomenon or by considering it on the basis of an apriori known model. The proposed control technique, has been tested experimentally on a suitably developed test set-up.
A novel data-driven SOH prediction model for lithium-ion batteries

With the increasing utilization of lithium-ion batteries, prognostics and health management (PHM) of batteries has become inevitable in energy system studies. Amongst, state-of-health (SOH) analysis introduces several challenges in online applications. In this respect, this paper presents a novel data-driven SOH prediction model based on machine learning methods, namely, feed-forward neural network (FFNN), support vector machine (SVM), and relevance vector machine (RVM). A novel feature extraction technique is employed, and a large dataset including 44 batteries with different cycle patterns is considered to test the accuracy of the proposed method. The results show that the maximum mean-absolute-percentage error (MAPE) of the proposed models for test batteries is 1.95%. The results demonstrate that the accuracy of the proposed method is suitable, and it can be easily implemented in large-scale applications.
Design and Analysis of a Flexible Multi-Output Wireless Power Transfer System with Variable Inductor

Multi-output wireless power transfer (WPT) system for a variety of loads has great potential to be used in practical applications, such as wireless office table, magnetic resonant imaging device and logistic sorting robots. The Multioutput WPT can power multiple receivers simultaneously. This paper presents the design and analysis of a flexible multioutput WPT system with variable inductor. Without compensation capacitor in the receiver side, only a receiver coil is connected that not only contributes to receiver side integration, but also makes the loads more flexible. By introducing a variable inductor (VI) in the transmitter side, each load can be controlled independently from any other loads, which makes it possible to power the multiple loads from the same inverter output. The proposed Multi-output WPT system presents the advantages of inherent zero-voltage switching (ZVS) for the inverter, fixed operation frequency and efficiency optimization. A prototype with multiple loads is built, and the experimental results have confirmed the validity of the proposed Multi-output WPT system.
Research on High Speed Cutting Parameter Optimization and Fault Diagnosis Technology

High speed cutting process is a very complicated process; cutting parameters have a significant effect on cutting process and play a key role in the process of product manufacturing. The overall scheme of high speed cutting parameter optimization and its fault diagnosis have been introduced. The mathematical model of the selected cutting parameters was established and the optimized parameters were obtained by combining the experimental design with the technology of data processing. The statistical description of high speed cutting process control was introduced and the fault diagnosis model of cutting parameter optimization by using the neural network was proposed. Finally, the mathematical model in the present study is validated with a numerical example. The results show that the present method solved the problem of poor universality of high speed cutting data effectively and avoided the inaccuracy of physical and chemical mechanism research. Meanwhile, the present study prevents the passive checks of the cutting and gets better diagnosis of the complicated cutting fault type.
Design and analysis of a new compliant microgripper with two working modes

The microgripper plays an important role in the microassembly system, which directly contacts the target object. The working range of a normally open or normally closed gripper is limited. In this paper, a monolithic flexible microgripper with dual piezoelectric-actuation modes is presented, which combines the characteristics of normally open and normally closed grippers. It has the advantage of enhancing the adaptability of the gripper for grasping objects of different sizes. Different types of bridge mechanisms and parallelogram mechanisms are used in the displacement amplification structure of the gripper. This design can improve the magnification efficiency and linearize the tip motion. According to the kinematics model, the displacement magnification of one-side gripper is analyzed. The crucial structural parameters affecting the magnification were selected to complete the structural optimization of the clamp. Finally, the optimized gripper is simulated and verified by performing finite element analysis. The simulation results reveal that the designed gripper has sufficient clamping stroke and good dynamic performance.
Behavioural Modelling of Common-Mode Chokes with Frequency-Dependent Permeability Core

Based on the measured impedance frequency response, this paper proposes a behavioral model of any common-mode choke (CMC) with magnetic core that exhibits frequency-dependent permeability. The model consists of several cascaded RLC parallel circuit blocks that resembles the actual measured impedance response in the frequency range of interest. The iterative algorithm to construct these RLC circuit blocks is described and the behavioral models of two commercially available CMCs are verified experimentally.
The Performance of PredNet Using Predictive Coding in the Visual Cortex: An Empirical Analysis

PredNet is a deep recurrent convolutional neural network developed by Lotter et al. The architecture drew inspiration from a Hierarchical Neuroscience model of visual processing described and demonstrated by Rao and Ballard. In 2020, Rane, Roshan Prakash, et al. published a critical review of PredNet stating its lack of performance in the task of next frame prediction in videos on a crowd sourced action classification dataset. While their criticism was nearly coherent, it is dubious, when observed, considering the findings reported by Rao and Ballard. In this paper, we reevaluate their review through the application of the two primary datasets used by Lotter et al. and Rane, Roshan Prakash et al. We address gaps, drawing reasoning using the findings reported by Rao and Ballard. As such, we provide a more comprehensive picture for future research based on predictive coding theory.
Effect of Rapid Thermal Annealing on Resistive Switching Uniformity of HfAlOx Based RRAM Devices

HfAlOx based RRAM devices were fabricated using atomic layer deposition by modulating deposition cycles for HfO2 and Al2O3. The effect of rapid thermal annealing (RTA) on the resistive switching uniformity of HfAlOx based RRAM devices was investigated. Compared to the as-deposited devices, the resistive switching uniformity of HfAlOx based RRAM devices after RTA treatment are remarkably improved. The uniformity improvement of HfAlOx based RRAM after RTA treatment is related to microstructure change in the resistive switching film.
Linearity asymmetry in FET resistive mixers

This paper investigates up/down conversion asymmetry in intermodulation distortion observed in measurements of resistive FET mixers. Symmetric behaviour is intuitively expected of such a topology, so a first principle analysis is carried out to determine the responsible mechanism. Previous analysis of up/down conversion asymmetry has focused on conversion gain in diode based mixers, whereas the effects investigated in this paper are for mixers with symmetry in this aspect. The aim is to fully understand the intermodulation mechanism, so that performance can be enhanced. The approach taken is to consider the mixer as a two-port nonlinear element driven by multiple frequency sources. Mixing performance then becomes a function of the relative frequencies and amplitudes, which is related to the mode of operation as an up or down converter. This investigation is performed with FET models of increasing complexity and physical accuracy. In this manner the effect on intermodulation and other mixer performance parameters can be isolated to those differences introduced with each model change such as the effect of adding higher order even/odd terms to the drain or gate non-linear model independently. The result is an understanding into the FET properties that contribute to intermodulation distortion. This knowledge is useful to designers as it allows educated modifications to mixer topology to obtain improved linearity. Results also give the ability to minimize the asymmetry, reducing the design cost involved in producing a separate solution for each mode. These results can also be used to guide modification of the physical structure of a FET for mixer applications.
A method for identifying specific load state of distribution network

Non-intrusive load monitoring (NILM) is a key component in the identification of smart electricity usage. Since there are many types of loads connected to the distribution network at the same time, that of them have variable frequency functions and do not have the characteristics of constant power, the existing load identification methods that focus on households are difficult to directly apply to the distribution network. Aiming at the load characteristics of the distribution network, this paper selects the elevator as a typical load to carry out a load identification experiment, and uses the measurement data conforming to IEC 61000-4-30 as input. The goal is to identify whether the elevator is in operation. In order to eliminate the computational pressure caused by irrelevant features, a differential feature extraction method based on Pearson's correlation coefficient is proposed, combined with a convolutional neural network, to realize elevator load status identification in an environment with multiple unknown loads. The results of using the measured data show that the method only needs a small number of samples to identify the elevator running state with complicated changes in operating power consumption, and the calculation accuracy is higher than that of the traditional machine learning method.
AC-DC Single-Phase Multilevel Converters with Floating DC-Link and Reduced Controlled Switches

This paper presents the DC-link voltage balancing for two single-phase unidirectional cascaded multilevel rectifiers. They are composed of a cascaded connection of two power cells (H-bridges), whose the higher voltage one has a reduced number of controlled switches while the lower voltage cell is a floating bridge. An asymmetrical voltage ratio was employed in presented topologies, allowing to increase the number of voltage levels, and consequently, the power quality provided. Each leg is either a Neutral-Point Clamped (NPC) leg, which generates 3 voltage levels, or a 2-level leg. The Pulse-Width Modulation (PWM) strategy based on level-shifted carriers is presented. The double-band hysteresis technique and a PI controller with a Phase-Locked Loop (PLL) system are integrated into the PWM strategy to control DC-link voltages. Simulation and experimental results are presented to show the performance of the balance scheme.
A Solar PV Based Smart EV Charging System with V2G Operation for Grid Support

This paper presents a solar photovoltaic (PV) based electric vehicle (EV) charging system with the ability to charge the EV battery storage system and with vehicle to grid (V2G) operation to support power grid. The charging system consists of a solar PV array with a single-ended primary-inductor converter (SEPIC) DC-DC converter, a bidirectional DC-DC converter for EV battery charging and three-level inverter with LCL filter for grid interface and associated controllers. The SEPIC converter is controlled with maximum power point tracking algorithm to extract maximum power from solar PV array and charge EV battery through a bidirectional DC-DC converter and controller. The designed controllers are capable to provide uninterrupted charging and grid support to enhance grid performance under disturbance and variable PV generation. The charger is also enabled with V2G power transfer for active and reactive power support and enhancement of fault ride through capability for the distribution grid with renewable energy sources. The proposed system is implemented in MATLAB/Simscape environment and results confirm that the proposed solar PV based EV charging system can charge the EV and provide grid support under varying irradiance and grid disturbances.
Distance Measurement Method Based on Average Interpupillary Distance

This paper presents a method of measuring the distance using a video camera designed to assess the distance the user is from the camera and be exploited industrially for applications such as Human-Computer Interaction (HCI). The measurement method uses a statistically determined average interpupillary distance for both men and women and has been implemented in Python. The eye position detection was performed using the OpenCV library.
Research and practice of health monitoring for long-spanbridges in the mainland of China

The large number of long-span bridges constructed in China motivates the applications of structural health monitoring (SHM) technology. Many bridges have been equipped with sophisticated SHM systems in the mainland of China and in Hong Kong of China. Recently, SHM technology has been extended to field test systems. In this view, SHM can serve as a tool to develop the methods of life-cycle performance design, evaluation, maintenance and management of bridges; to develop new structural analysis methods through validation and feedback from SHM results; and to understand the behavior of bridges under natural and man-made disasters, rapidly assess the damage and loss of structures over large regions after disasters, e.g., earthquake, typhoon, flood, etc. It is hoped that combining analytical methods, numerical simulation, small-scale tests and accelerated durability tests with SHM could become the main engine driving the development of bridge engineering. This paper demonstrates the above viewpoint.
A Control Method Based on Power Factor for Improving Output Voltage Stability and Efficiency of LLC Converter in Wide Range of Output Voltage and Load Impedance

The LLC converter is attractive for its small volume and comparatively high efficiency. However, the application of this converter is limited to the power supply to a static load with almost constant output voltage and current because the LLC design covering a wide range in the output voltage and the load variation can deteriorate the output voltage stability and efficiency. This paper addresses this issue by proposing a novel control method. Unlike the conventional control, which adjusts the operating frequency to stabilize the output voltage, the proposed control adjusts the power factor of the transformer primary-side to achieve the same excellent dynamic performance as the buck chopper. Simulation supported the effectiveness of the proposed control at a wide load variation range.