Miracle-dz/UniFAR-FTUs huggingface dataset:
Sputtered PZT pMUT with Bias-Tunable Electromechanical Coupling Coefficient for Air-coupled Ranging Applications

We report preliminary wafer-level measurement results of air-coupled phase vapor deposition (PVD) PZT pMUTs for ranging applications recently fabricated in our Lab-in-Fab 8-inch line. Dual-port PVD PZT pMUTs designed to resonate in the 100kHz range were fabricated based on a $\boldsymbol{2\mu} \mathbf{m}$ - thick PZT film on a $\boldsymbol{4\mu}\mathbf{m}$ -thick silicon diaphragm. The standard deviation of the PZT stack capacitance was <2% across the wafer. Despite the sensitivity of compliant diaphragms to film residual stress, the standard deviation of frequency was <5%. Out of 16 sites across wafer probed, all devices were verified to be in good working condition. Given the strong piezoelectric constant of the PZT film $(\mathbf{e}_{\boldsymbol{31,}\mathbf{f}}\boldsymbol{\sim 16}\mathbf{C}/\mathbf{m}^{\boldsymbol{2}})$ and compliance of the diaphragm designed for ranging applications, we demonstrate large tunability in frequency (120-210kHz), $\mathbf{K}_{\mathbf{t}}{}^{\boldsymbol{2}}$ (1-7.3%), and quality factor (50–100) for a bias voltage range of0-40V. Results have been obtained without poling of the PVD PZT film. No unresponsive devices were found.
Influence of Contact Resistance Deterioration of Contact Finger on Electrical Thermal Coupling Field Distribution in GIS

In recent years, too many GIS discharge accidents caused by contact overheating of current carrying connection structure have occurred in China, which seriously threatens the safety of power grid. It is necessary to study the influence of contact resistance deterioration of contact finger on the distribution law of electrical thermal coupling field of GIS basin insulator. In this paper, the contact finger connection structure used in GIS current carrying system is considered, and the three-dimensional thermal flow field distribution of GIS is simulated by using the three-dimensional electromagnetic thermal flow coupling field simulation calculation method. The influence of the deterioration degree of contact resistance of contact finger on the thermal field distribution of GIS is analyzed. The distribution law of electrical thermal coupling field of GIS equipment caused by the change of contact resistance and current carrying capacity of central guide rod plug-in structure is studied, which is of great significance to practical engineering.
Impact of Gravity Waves on Marine Stratocumulus Variability

AbstractThe impact of gravity waves on marine stratocumulus is investigated using a large-eddy simulation model initialized with sounding profiles composited from the Variability of American Monsoon Systems (VAMOS) Ocean–Cloud–Atmosphere–Land Study Regional Experiment (VOCALS-Rex) aircraft measurements and forced by convergence or divergence that mimics mesoscale diurnal, semidiurnal, and quarter-diurnal waves. These simulations suggest that wave-induced vertical motion can dramatically modify the cloud albedo and morphology through nonlinear cloud–aerosol–precipitation–circulation–turbulence feedback.In general, wave-induced ascent tends to increase the liquid water path (LWP) and the cloud albedo. With a proper aerosol number concentration, the increase in the LWP leads to enhanced precipitation, which triggers or strengthens mesoscale circulations in the boundary layer and accelerates cloud cellularization. Precipitation also tends to create a decoupling structure by weakening the turbulence in the sub.
Informational Model for Calculating Road Surface Life and Repairs and the Rational Financing Thereof

The article analyzes the use of geographic information system (GIS) to determine the indicators of longitudinal and transverse flatness of pavement and residual life of pavement structures with subsequent prediction of changes in these indicators over the years of road operation. The existing methods for evaluating the above-mentioned indicators are considered. The forecasting is based on the calculation of the residual total number of design load applications and the total number of automobile passes in the traffic lane, for which the forecasting is carried out. The article shows the possibility to determine the indexes of longitudinal and transversal flatness as well as residual life of the pavement structure at the present time by the data acquired by the video monitoring cameras. Video surveillance cameras record the dimensions of vehicles and organize the data on the structure and intensity of traffic. This information can be transmitted to the GIS in continuous synchronization with the GIS server.
FBAR Oscillator and MEMS Tunable VCSEL to Generate the Probe Lasers for Microfabricated Atomic Clock

In this paper, we describe several new approaches to cost reduction for the realization of ultraminiaturized atomic clocks. One is the development of a wavelength tuner for vertical-cavity surface-emitting lasers (VCSELs) for the atomic clocks. Our VCSEL is designed so that an electrostatic actuator can control the length of the laser cavity, eliminating the offset from the desired central wavelength even in postprocessing. This is effective in reducing the screening cost, which is the main factor driving up the cost of laser chips for coherent population trapping (CPT) atomic clocks. In another approach, we used a thin film bulk acoustic resonator (FBAR) for the atomic clock oscillator to significantly reduce the circuit scale and added a balun circuit and a gain adjustment circuit. This oscillator was manufactured using a legacy process with a line width of 180 nm, and good oscillation was successfully confirmed in the 3 GHz band.
A Multiplying Delay-Locked Loop design with low jitter and high linearity

In this paper, a Multiplying Delay-Locked Loop (MDLL) for high-precision Time to Digital Converter(TDC) is proposed, which has low jitter and high delay linearity. In order to reduce the phase noise, an internally compensated charge pump(CP) is used to achieve better current matching between charging and discharging. The improved reverse differential delay cell structure is used to improve the resolution of multi-phase clock. An MDLL with an output frequency of 80-240MHz and an area of 0.08mm2 is realized by using 0.18um CMOS process. The test results show that the total power consumption under 1.8V power supply is 11.52mW@240MHz, RMS jitter is 10ps@240MHz.
Contribution to Reconfigured Rectifiers Fed Gas Metal Arc Welding Process

The welding process is among the most important technologies used and included in the world of manufacturing, related to welding and metals, there are several machines related to welding, among the most important, the most common, and the most recent of them is a machine of Gas Metal Arc Welding, it is fed by the static converter i.e. the rectifier. This paper deals with the study of the behavior of the welding machine GMAW in healthy and faulty cases, under the faulty case; the open-circuit fault occurs at the switches in one of two rectifiers. This paper proposes the inclusion of a new method for diagnosing the faults; it adopts the threshold band technique for early detection of open-circuit faults related to Thyristor switches, it also depends on the polar coordinates technique to accurately locate the faulty switches. Therefore, this paper proposes the installation of fault-tolerant rectifiers. The results obtained in this manuscript demonstrate the efficacy of each of the proposed diagnostic methods the fault-tolerant rectifiers included, all this contributed to ensuring the smooth running of the welding process; by maintaining the work-piece on one hand and the other hand, protecting the network from current distortions caused by open-circuit faults.
Energy Equalization of Battery Pack with Inconsistent Capacity

Battery energy balance is the key technology of energy storage system, which requires that the state of charge(SOC) of each energy storage unit is consistent. Generally, the aging battery packs not only have inconsistent SOCs, but also the battery capacities are different. In this paper, a balancing strategy based on model predictive control(MPC) is presented to achieve the dynamic equalization of SOC under the condition of inconsistent capacities. Considering the battery capacities, an optimization algorithm is presented to optimize the input power and output power of the equalizers for the different working states of the battery pack, which can avoid over-charging or over-discharging of the batteries with low capacity. Simulation results verify the effectiveness of the presented method.
Stator Flux Observer for the Sensorless Speed Control of Synchronous Machines with Uncertain Torque Constant

In this paper, a recently designed adaptive stator flux observer (SFO), which provides estimates of rotor position and torque constant for surface mounted permanent magnet synchronous machines (PMSMs), is included in a speed sensorless control. Simulations and experimental results are carried out in order to evaluate the robustness of the whole control architecture with respect to uncertainties in the electrical parameters of the motor, as well as to the mismatch between the actual stator voltages imposed to the PMSM and the ones used for the observer, especially when low speeds are involved.
A 250Mbps 100kV/µs CMTI On-Chip Double-Isolated Transformer-Based Digital Isolator

This paper presents a double-isolated on-chip transformer-based digital isolator exploiting integrated double SiO2 galvanic barriers to achieve an isolation rate of 4kV. The isolator employs pulse polarity modulation to reduce the power consumption while maintaining a high data rate and high common mode transient immunity (CMTI). Simulation results show that the proposed isolator achieves a 250Mbps maximum data rate with a 5ns propagation delay and a 100kV/µs CMTI performance. With a load of 15pF, TX and RX consume 0.32mA and 3.4mA currents at a 1Mbps data rate and 11.7mA and 3.5mA currents at a 250Mbps data rate, respectively.
Comparative study of two types of high-frequency transformers in a 20-kW Phase-Shifted Full Bridge converter application

The paper presents a description of two types of high-frequency transformers with a power rating of over 20 kW - one made of planar cores and windings in the form of thin copper foil and the other built with E-type cores and Litz wire. Results of comparative tests conducted with the isolated phase-shifted full-bridge DC/DC converter are presented. The obtained results in the form of waveforms and electrical measurements with a precise power analyzer clearly indicate the advantage of the solution with the Litz wire winding. Due to the distorted current in the AC circuit and high frequency of the fundamental harmonic, a large part of the power loss in the transformer is the conduction loss. Possible causes of worse results in the case of windings made of copper foil are also indicated.
One New Terminal Reaching Law Based Sliding Mode with Direct Thrust Control for the Linear Induction Machines in Metro Transportation

In this paper, one terminal reaching law based sliding mode (TRL-SMC) under direct thrust control (DTC) is proposed for the linear induction machine (LIM) to improve the dynamic response of the LIM in terms of the faster transient response, smother steady-state operation, smaller tracking error and lower thrust ripple than those of the conventional DTC (CDTC) and exponential reaching law based SMC (ERL-SMC) with DTC, persuasively. The TRL-SMC based DTC is fully compared with the CDTC and existing ERL-SMC based DTC under the different working scenarios through the extensive experimentation on a prototype of two 3 kW arc induction machines.
Testing the Martingale Property of Exchange Rates: A Replication

In this paper, we test the martingale property of a set of U.S. exchange rates already analyzed in a recent paper by Yilmaz [J. of Buss. and Ec. Stat., 2003]. We claim that the tests used by Yilmaz are not the most convenient to test the martingale hypothesis (or the equivalent martingale difference of the returns); hence, we compute a recently proposed test by Kuan and Lee [Stud. in Nonlin. Dyn. and Econ., 2004] and compare our results to Yilmaz's. Striking differences arise, which can give a clue about the type of data generating process governing the evolution of exchange rates in each sub-period.
Patient-specific treatment planning for clinical interstitial ultrasound thermal ablation of focal prostate cancer

Catheter-based interstitial ultrasound applicators, previously applied for delivering hyperthermia in the prostate, and the TheraVision system are FDA 510(k) cleared for soft tissue ablation. In the present study, 3D patient-specific finite difference models representing prostate and focal disease were developed and applied to (1) develop pre-treatment planning tools and (2) evaluate the temperature/thermal dose distributions as a means to optimize the ultrasound applicator parameters and positioning for controlled and selective ultrasound thermal ablation of focal prostate cancer.
An Analog Wafer Map Clustering Model with Deep-Learning Based Data Augmentation and Feature Extraction

Process deviations during semiconductor manufacturing have significant influence on wafer yield. Tasks such as failure type recognition, outlier detection and etc. can be accomplished by checking wafer maps. In this study, unsupervised feature clustering on unlabeled analog wafer maps is our primary concern. Each wafer map indicates a test parameter and the task is finding cluster of parameters sharing a similar pattern. Convolutional variational auto-encoder is used to extract features and the features are clustered by density-based algorithm to replace K-means in previous works. Besides, rather than supervised data augmentation such as policy-search system, we construct a deep convolutional generative adversarial network for unsupervised data augmentation. Performance of the study is tested on real-world and synthetic wafer maps and the proposed method improves silhouette coefficient by 31 percent compared to previous studies.
A Digital Twin Based Fault Location Method for Transmission Lines Using the Recovery Information of Instrument Transformers

The parameters of transmission line vary with environmental and operating conditions, thus the paper proposes a digital twin-based transmission line model. Based on synchrophasor measurements from phasor measurement units, the proposed model can use the maximum likelihood estimation (MLE) to reduce uncertainty between the digital twin and its physical counterpart. A case study has been conducted in the paper to present the influence of the uncertainty in the measurements on the digital twin for the transmission line and analyze the effectiveness of the MLE method. The results show that the proposed digital twin-based model is effective in reducing the influence of the uncertainty in the measurements and improving the fault location accuracy.
ULTRAVIOLET ABSORPTION SPECTRA OF HCN AND DCN: I. THE α—X AND β—X SYSTEMS

The ultraviolet absorption spectra of HCN and DCN have been investigated below 2000 A. Four band systems have been found of which two, α—X and β—X, are described and analyzed in the present paper. At the long wavelength end the α—X system in both HCN and DCN consists of simple progressions of sharp bands whose fine structure has been measured. At shorter wavelengths diffuseness (predissociation) sets in gradually but at somewhat different energies in HCN and DCN. Both the vibrational and rotational analyses lead independently and unambiguously to the conclusion that in the upper state, α, unlike in the ground state, the molecule is non-linear. The geometrical parameters obtained from the rotational fine structure are r0(CH) = 1.140 A, r0(CN) = 1.297 A, and H—C—N = 125.0°. Two vibrational frequencies in the α state are established: for HCN, ν1 = 1506, ν2 = 949; for DCN, ν1 = 1506, ν2 = 735 cm−1. The CH stretching frequency has not been found.The β—X system has been clearly observed only for DCN. In HCN it .
Design of a broadband millimeter-wave quasi-optical mode converter for the low power test platform of the ECRH system on J-TEXT

For the low power test platform of the ECRH system on J-TEXT, a broadband millimeter-wave quasi-optical mode converter from TE11 mode to HE11 mode is studied. The mode converter is a corrugated horn antenna with the sine-parallel profile. The effects of different slot numbers in the mode converter and slot picth on the bandwidth of corrugated horns are compared and the appropriate parameters were determined using mode matching method. The simulation results show that in the frequency from 90 GHz to 120 GHz, the relative power of the HE11 mode can reach more than 97%, where the relative power of HE11 mode at the center frequency 105 GHz can reach more than 98.8%. The designed sine-parallel profile has the advantage that the output beam waist radius is at the output port.
Comparison of superimposed voltage tests with spark gap and coupling capacitor at a gas-insulated model arrangement

Superimposed voltage tests are widespread to qualify HVDC equipment. Two possible test circuits are used, which result in different voltage shapes: superimposition by a coupling capacitor or by a spark gap. So far, there is no data available, which compares the resulting breakdown voltages of both methods with each other. This paper closes this gap by determination of the breakdown voltage at a model arrangement using both methods. The investigation was focused on gas-insulated systems, which are a typical application in HVDC. The model arrangement was built such that it represents a typical gas-solid interface in a coaxial GIL assembly. HVDC effects were included by heating of the earthed electrode. The determination of reproducible data was challenging, but could be achieved by adaptions inside the test circuit, as well as a suitable test procedure. The collected data with the built test arrangement is presented and discussed further in this paper. Based on the results a first conclusion is given, whether the different voltage shapes resulting from the use of a coupling capacitor and a spark gap, respectively, also result in different breakdown voltages.
Optimized T-type multilevel converter under Finite Set Model Predictive Control

The paper presents an optimized T-type multilevel converter topology following a systematic procedure. The topology is assessed according to the quality of the output energy, efficiency and the cost. A special attention is dedicated to the performance evaluation of the proposed topology under Finite Set Model Predictive Control FS-MPC modulation well known by its difficulty in quantifying the power losses since the switching frequency is variable. An approach to determine the switching frequency and the duty cycle for each switch is presented and explained. This approach permits accurate calculation of the losses using FS-MPC modulation technique. The extensive simulation results show that, when compared to other similar existing topologies, the performance of the proposed topology is better in terms of reduced power losses, higher output power quality and lower cost.
Trapping of Microbead Spheroids by pMUTs in Microfluidic Channels Embedded with an Acoustic Reflector

In this paper, a piezoelectric micromachined ultrasound transducer (PMUT) embedded microfluidic device is proposed for acoustic particle trapping in a microfluid channel. The proposed device traps microparticles in a pressure node along the vertical axis resulting from the reflection of acoustic waves generated by PMUT actuation to set up a standing wave. We have successfully demonstrated trapping of microbead spheroids/agglomerates according to their size. This study opens up a new avenue for particle manipulation based on PMUTs for integrated microfluidic systems.
Design Principles of Secure Certificateless Signature and Aggregate Signature Schemes for IoT Environments

Certificateless cryptography resolves the certificate management problem of public-key cryptography and the key-escrow problem of identity-based cryptography. An aggregate signature scheme which allows to aggregate <inline-formula> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> distinct signatures on <inline-formula> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> distinct messages of <inline-formula> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> distinct signers into a single signature reduces communication overhead and computational cost. Due to the suitability of certificateless signature (CLS) and certificateless aggregate signature (CLAS) schemes for IoT environments, similar CLS and CLAS schemes have been proposed for a long time and, despite their security proofs, they have been attacked and modified to prevent the attacks. Even now, similar design methods and similar attacks on the schemes are being repeated. In order to prevent the similar attacks on the schemes, it is necessary to analyze their causes and vulnerabilities. In this paper, we first show that recently proposed five CLS and CLAS schemes are insecure against universal forgery attacks, type I attacks, type II attacks or malicious-but-passive-KGC attacks. We discuss their security flaws, causes and countermeasures. We then present design principles to prevent various algebraic attacks including our attacks. The design principles will help in the construction of secure CLS and CLAS schemes against the previous attacks and potential attacks.
A review on direct digital conversion for biomedical signal acquisition ICs

Biomedical signals like Electrocardiogram (ECG), Electroencephalogram (EEG) and photoplethysmography (PPG) are recorded routinely to provide helpful information for early diagnosis of disease. A low power consumption is very important to allow long term ambulatory monitoring with battery powered systems. Direct digital conversion (DDC) technique has been proposed in recent years which emerges the preamplifier and data converters, reducing the complexity of readout chain and thus its power consumption. This paper provides a review on DDC for biopotential signals and bio-optical signals acquisition. The state-of-the-art DDC based readout architectures together with circuit implementations are provided.
Converse Lyapunov–Krasovskii theorems for uncertain time-delay systems

Abstract In this article, we give a collection of converse Lyapunov–Krasovskii theorems for uncertain time-delay systems. We show that the existence of a weakly-degenerate Lyapunov– Krasovskii functional is necessary and sufficient condition for the global exponential stability of the time-delay systems. This is carried out using the switched system transformation approach.
Supervised Learning Algorithm Based on Spike Back Reconstruction

The error backpropagation mechanism adjusts the synaptic weights by feeding back the total error signal layer by layer in a neural network, which is unreasonable in biology. In this paper, the supervised learning algorithm based on spike back reconstruction is proposed, which gets rid of the concept of total error, and derives the local error signal of each layer of the network by generating the desired spike signal of each neuron. The reconstruction spike signal is directly fed back to the presynaptic local neurons, thus the training of the multi-layer neural network can be realized through local training mode with biological interpretation. We derive the spike back reconstruction learning algorithm for deep spiking neural networks, in which the learning rule is expressed by the inner product operation of spike trains. Additionally, the spike train learning experiments are applied to verify the effectiveness of the proposed algorithm, and the impact of relevant factors on the learning performance of the algorithm is also analyzed. Experimental results demonstrate that the learning ability of spike back reconstruction method is obviously superior to the traditional error backpropagation mechanism.