Miracle-dz/UniFAR-FTUs huggingface dataset:
Observer-Based Adaptive Fuzzy Tracking Control Using Integral Barrier Lyapunov Functionals for A Nonlinear System With Full State Constraints

A new fuzzy adaptive control method is proposed for a class of strict feedback nonlinear systems with immeasurable states and full constraints. The fuzzy logic system is used to design the approximator, which deals with uncertain and continuous functions in the process of backstepping design. The use of an integral barrier Lyapunov function not only ensures that all states are within the bounds of the constraint, but also mixes the states and errors to directly constrain the state, reducing the conservativeness of the constraint satisfaction condition. Considering that the states in most nonlinear systems are immeasurable, a fuzzy adaptive states observer is constructed to estimate the unknown states. Combined with adaptive backstepping technique, an adaptive fuzzy output feedback control method is proposed. The proposed control method ensures that all signals in the closed-loop system are bounded, and that the tracking error converges to a bounded tight set without violating the full state constraint. The simulation results prove the effectiveness of the proposed control scheme.
Communication management for reliable service based IoT systems

Internet of Things (IoT) systems are becoming more and more popular. Moreover, service-based approach to IoT systems development is practically a standard utilized in their architecture. uti. IoT communication problems ware discussed in many articles about wireless communication, sensor networks or cloud computing. However the topic of high-level end to end communication in IoT systems is much less often the point of researchers’ interest. Despite that, the reliability of communication makes much more sense especially when it is considered at the application layer. Furthermore, networks utilized in IoT systems are usually virtual and software-based. Due to this fact, it is reasonable to take consider this problem with a novel and adequate approach, rather with classical models of communication resource allocation. In this article authors presented an idea of reliable communication management for IoT systems based on resource allocation. This idea is discussed in context of service-based IoT system lifecycle, especially considering the stages of resource allocation and services execution. Concerning the presented concept, three algorithms were prepared and tested in the simulation process.
Robust Multi-kernel Generalized Maximum Correntropy Filters

The traditional multi-kernel filtering algorithms are proposed by combining multiple kernel with the second similarity measure. Nevertheless, these multi-kernel filters suffer from both heavy computation burden and divergence for impulsive noise environments. To deal with these challenges for online applications, the multi-kernel generalized maximum correntropy (MKGMC) algorithm is developed for improving both precision and stability under the generalized maximum correntropy criterion. To alleviate the complex network structure of MKGMC, using the vector quantization strategy in MKGMC develops quantized MKGMC (QMKGMC) to reduce the computational and spatial complexity. From the viewpoints of precision and stability, the proposed algorithms outperform other typical compared algorithms on time series prediction.
Mesoporous Silica: An Efficient Nanoreactor for Liquid−Liquid Biphase Reactions

Mesoporous silica can be used as a nanoreactor for liquid−liquid biphase reaction without any phase transfer reagent and organic cosolvent. High conversions (up to 89%) are achieved with low catalyst loading. This is attributed to the amphiphilic mesochannels, which can provide suitable accommodations for both hydrophilic and hydrophobic molecules.
A Hybrid Si/GaN 5-Level Flying Capacitor Single-phase Inverter and its Current Ripple Analysis

The GaN flying capacitor multilevel converter (FCMC) offers a better harmonic spectrum and attains higher voltages with a limited maximum device rating but suffers from high components quantity and cost. In this paper, a Si/GaN hybrid single-phase 5-level flying capacitor multilevel inverter (FCMI) is proposed with a much-reduced component quantity and cost. The proposed hybrid FCMI consists of only two pairs of GaN devices and a pair of line-frequency Si devices, compared with four-pairs eight high-frequency GaN devices in a conventional five-level FCMI. Furthermore, the proposed FCMI has a twice effective voltage. The operation principle and modulated strategy are detailed discussed. Meanwhile, a new current ripple model is introduced to investigate the output performance. A 600V, 5-level hybrid Si/GaN converter prototype is designed and built. The experimental results confirm the validity and effectiveness of the presented converter and current ripple model.
Efficiency and Linearity of Digital "Class-C Like" Transmitters

An energy-efficient, intrinsically linear, digital "class-C like" operation-mode is investigated for use in high-power digital transmitters (DTXs), which target next generation mMIMO base stations that offer lower costs, higher integration, and improved system efficiency. The proposed operation utilizes class-B/C output matching in combination with duty-cycle reduction and current-mode operation of a segmented output stage. Its performance in terms of efficiency, output power, and linearity is benchmarked with analog class-B/C operation. The proposed digital "class-C like" operation has been experimentally verified using a fully-digital, dual TX line-up with VT-shifted segmented LDMOS output stages. All output stage segments are individually controlled by high-speed digital drivers implemented in 40 nm CMOS technology. The realized prototype provides 25.9 W (CW) output power with 75.7 % drain and 72.9 % system efficiencies, at 930 MHz and at 28 V drain supply.
Sequence Impedance Modeling and Stability Analysis of Three-phase Two-stage Power Conversion System

Power Conversion System (PCS) is the critical interface connecting energy storage devices and the utility grid. In this paper, the research is developed on two-stage PCS consists of DC/DC converter regulating battery current and DC/AC converter regulating voltage of DC bus. The positive-sequence and negative-sequence impedance of the two-stage PCS at PCC (Point of Common Coupling) is modeled through harmonic linearized method with mirror frequency coupling effect considered. The validity of the impedance model obtained is verified through simulation, simulation results indicates that the proposed approach achieved a desirable accuracy. With the obtained impedance, stability analysis of PCS against grid could be implemented through Nyquist criteria, the analysis proves to be right by simulation.
Failure Analysis of a 100 Tesla Pulsed Magnet

A triple-coil pulsed magnet aiming at 100 T (Tesla) was developed and tested at the Wuhan National High Magnetic Field Center (WHMFC). The outer coil was powered by a 100 MJ pulse generator and a battery bank connected in series. The middle and inner coils were energized by 25 kV capacitor banks. The magnet failed at 83 T, while the whole structure remained intact. The failure process is analyzed by using the recorded waveforms of the voltage and the current, as well as disassembling and dismantling the failed magnet. It shows that the electrical breakdown occurred between the middle and outer coils as well as within the inner coil, and the inner coil broke down before the middle and outer coils. Based on the previous analysis, the time line of the failure process is given. Additionally, the possible reasons for the failure are also discussed. The results show that the buckling and fiber fracture of the inner coil might cause the accident.
A 1000W Wideband Recursive Four-way Doherty Amplifier for Base-station Application

An optimized wideband load impedance selection approach and recursive four-way Doherty power amplifier (DPA) combining topology are introduced in this paper. Theoretical analysis indicates low Q-factor matching network can be achieved adopting this approach, and it will be easier to obtain high efficiency adopting recursive structure. For verification, a 1000W wideband recursive four-way DPA using LDMOS devices operating from 760MHz to 960MHz is implemented. The prototype exhibits the peak power between 59.5dBm and 60.5dBm and an average drain efficiency between 48% and 54% with 9.9 PAR WCDMA signal. It can be linearized under -51dBc level with 2C-LTE signal at an average output power of 50dBm with 200MHz carrier spacing.
Technique for Load-Independent Millimeter-Wave Output Power Monitoring for Mass-Volume Testing

This paper presents a circuit technique for an accurate output power measurement of mm-wave power amplifiers during mass-production on-wafer testing of integrated transceivers. Basic functionality is tested in a single testbed insertion by contacting all the chip pads simultaneously using a specifically designed probe card. The output power is usually measured via power detector and monitored as a DC voltage read-out. However, the large parasitics of the probe card pins, placed at the RF pads corresponding to power amplifier output, may significantly alter the load seen by the power amplifier due to an undefined impedance and lead to a false measured power. We propose a simple circuit technique how to overcome this error and make the output power detection independent of the parasitic load seen at the RF pads. We derive a theory and verify it in simulation. For load swept over the entire Smith Chart, the absolute inaccuracy of detected power is less than 2 dB.
Accelerating Automatic License Plate Detection in the Wild

Automatic license plate detection (ALPD) and recognition systems are becoming ever more widely used in the world. At present, most of the ALPD systems for Chinese license plates(LPs) are either slow or less accurate, which can affect the subsequent stage of license plate character recognition. In this paper we propose a fast and accurate ALPD system for images taken in the wild. We first design and train a YOLO-like [14] but simpler network for fast LP localization; then we develop another network to find the four corner points of the LP within the previously selected rectangular area; finally we use perspective projection to convert the LP to the front view for easy subsequent recognition. CCPD [2] dataset is used for training the networks. Experimental results show two distinctive advantages of the proposed method. First, the proposed method is both very accurate and robust. The recognition accuracy rate has reached 98.6% over a wide range of test images, especially those image types not contained in the training set. Secondly, the proposed method is very fast. The whole LP detection and recognition system can process images of size 720P at the rate of 33.4 frames per second, far exceeding previously reported performance in terms of both accuracy and speed. In addition, we find that many of the LP corner labels are not accurate yet the output from our method give very accurate LP corner coordinates. So we use our network to correct the LP labels in the CCPD dataset.
Stability analysis of VSC based on SISO equivalent in current control time scale

Oscillations in current control (CC) timescale (higher than 50 Hz) caused by voltage source converters (VSCs) integrating into the weak grid have occurred. However, relevant studies lack enough mechanism cognitions of instability of such system. In order to guide the parameter setting of the controllers, this paper first presents a small signal model of VSC based on motion equation concept. Secondly, a SISO equivalent method which can quantitatively analyze the interaction between variables in MIMO is introduced. Thirdly, the influence of phase locked loop (PLL) bandwidth, current controller parameters in the d-axis and q-axis and filter bandwidth on the feedforward branch of terminal voltage on stability is analyzed based the SISO equivalent method, which can help engineers to study the mechanisms of the voltage amplitude/frequency stability. Finally, the simulations in time domain verify the correctness of the analyses.
RFMC: a spending-category segmentation

With regards to an exceptionally competitive financial market impacted by legislative changes and with the evolution of customer’s behavior, banks must provide customer-centric assistance, services and products. To understand their customers, segmentation is a classical technique where banks classify their customers following well-defined banking rules or customer profiles (RFM). In this paper, we propose a novel segmentation, called RFMC that better represents customers’ behavior by using, not only customers’ profiles but also a categorization of their spending. We show that, compared to the classical RFM-based segmentation, RFMC allows for advanced services that better fulfill customer’s wishes, expectations and needs, by leveraging offers that fit their spending behaviors.
Distributed Optical Fiber Intrusion Warning Based on Multi-model Fusion

Long-distance pipeline is the important way for transporting resources such as oil and natural gas. At present, construction activities along the pipeline have become one of the important threats for pipeline security. In this paper, by laying distributed optical fiber sensors along the pipeline, the phase-sensitive optical time domain reflectometer($\varphi$-OTDR) technology is utilized to monitor the vibration signal along the pipeline. A data-driven warming scheme is designed based on multi-model fusion to decrease the false alarm rate resulted from the complex environment and external disturbances. The scheme consists of data preprocessing, feature extraction and multi-model fusion method. By this means, a more accurate warning system of distributed optical fibers is realized. Experimental studies have also been conducted to validate its practicability.
Existence of Lossy Objects through Power Transmission Path of Resonator-Coupled Type Wireless Power Transfer System

The influence of lossy objects for the Resonator-Coupled type Wireless Power Transfer (RC-WPT) system by using single-spiral and dual-spiral resonators has been studied. Up to now, the resonant frequency of single-spiral and dual-spiral resonators have been set as the same but the size of them have not been set equal in our RC-WPT system. In this paper, another single-spiral and dual-spiral resonators whose resonant frequency and diameters are the same have been refabricated and the influence of lossy objects located on power transmission path for the RC-WPT system with new single-spiral and dual-spiral resonators has been re-compared. From the experimental results, it has been presented that the RC-WPT system with lossy objects using dual-spiral resonator has shown better performance than the system using single-spiral resonator.
Compression, thermal expansion, structure, and instability of CaIrO3, the structure model of MgSiO3 post-perovskite

Abstract Analysis of pressure-temperature dependent monochromatic X-ray powder diffraction data yield the bulk modulus [KT = 180.2(28) GPa] and thermal expansion coeficients [α0 = 2.841(34) × 10-5 K-1; α1 = 3.37(48) × 10-9 K-2] of CaIrO3, the structure model for post-perovskite MgSiO3. CaIrO3 is orthorhombic (Cmcm, space group 63, Z = 4) with best-fit unit-cell parameters, a = 3.14147(5) Å, b = 9.87515(19), c = 7.29711(11), and V = 226.3754(78) Å3 at 1 bar and 300 K. The c-axis of CaIrO3 has a small compressibility and a large thermal expansion when compared to the other principal axes. Rietveld structure refinement reveals changes in CaIrO3 as a function of temperature in terms of IrO6 octahedra distortion. Dissociation of CaIrO3 at high temperature has possible implications for the post-perovskite MgSiO3 structure, Earth.s lower mantle, and D’’ layer.
High Permittivity CPW-SIW Power Divider for Antenna Feed Networks in Airborne Phased Arrays Applications

An extremely compact design of a power divider in Substrate Integrated Waveguide (SIW) and fed by means of a Coplanar Waveguide (CPW) line is presented in this paper. The proposed solution presents a relative low insertion loss and good adaptation (measurements show an S11 better than −20 dB for the centre frequency and below −15 dB for a 30% bandwidth) in X-band, despite the use of a substrate with a high dielectric permittivity (εr = 9.8). In order to validate the design, various topologies of the power divider are manufactured, measured and compared with the simulated data. These power splitters will be implemented in the feed network of a phased array for an airborne radar system with Digital Beamforming capabilities operated by the German Aerospace Center.
Data Driven Network Monitoring and Intrusion Detection using Machine Learning

With the widespread use of the Internet, cybersecu-rity is a significant challenge faced by the world. Because of the tremendous amount of internet traffic and increased network complexity, it becomes overwhelming for network analysts to manually monitor the traffic flows and to identify intrusions in large networks. In order to adequately and effectively analyze network traffic for intrusions, multiple machine learning based intrusion detection models were proposed to detect intruders using packet traces captured in the network. It was shown that with proper training, the machine learning models could identify malicious packets accurately. In addition, data pre-processing has been performed to mitigate the problem of unbalanced datasets. Experiments show improved performance as expected. Furthermore, a multi-class classifier was built to classify not only malicious or benign traffic but also to extend labels upon the malicious data. This insures the multiclass classifiers could classify each malicious packet as a specific type of attack such as DDOS, BOTNET, and more.
Single-Chip 100-Watt S-band Power Amplifier in 0.25 μm GaN HEMT MMIC Technology

A 100 W single chip GaN HPA for radar applications is designed, manufactured and measured. This HPA delivers a peak output power of 107 W at a PAE of more than 55 %. The operational frequency band of the HPA is from 2.9 GHz to 3.4 GHz. High quality non-linear transistor models and advanced simulations of RF performance, amplifier stability and thermal behaviour have led to a first-time-right design.
A New H-plane T-junction Waveguide Power Divider Covering the Full W-band

This paper presents, for the first time, a new H-plane T-junction waveguide power divider operating over the full W-band. All of the existing designs of the H-plane T-j unction power divider do not operate over the full waveguide band with reflection coefficient of less than −20 dB. Although a full-band performance is possible with a Y-junction, it is preferable in many applications to use T-junction power dividers for space saving. Using a septum, two small cavities and an input matching transformer, we were able to design an H-plane T-junction power divider operating over the full band of the WR-10 waveguide (W-band: 75–110 GHz) with reflection coefficient of less than −20 dB. A table is presented for optimum dimensions of the proposed waveguide power divider normalized with the broad-wall width so that the proposed power divider can readily be applied to other standard waveguides.
UWB Antenna for Application in Impulse Radio Regime

In this paper suitability of an antenna for UWB communications is evaluated. The antenna under test is a proximity-fed circular patch antenna loaded with two rectangular slots surrounded by two concentrical rings. The antenna achieves a 10 dB return loss bandwidth from 2.95 to 9.2 GHz. To verify the potential of this antenna for UWB application its Mean Realized Gain (MRG) and System Fidelity Factor (SFF) is calculated. Its system-fidelity factors are calculated using CST Microwave Studio. The process of simulation for deriving SFF is explained in detail. The achieved SFF is greater than 86% for the antenna under test, which verifies its suitability for UWB communication. The MRG is computed using High-Frequency Structure Simulator (HFSS) through its entire bandwidth. The computed MRG verifies that the antenna’s pattern shape and gain are maintained throughout the frequency band.
Extraction Technology of Line of Sight Angular Velocity with Missile Rolling

When the missile is rolling, the roll angular velocity of missile will be coupled with the stable platform of seeker, causing the output of the seeker gyro has an additional signal related to the roll angular velocity of missile based on the real LOS (line of sight) angular velocity. Based on the principle of LOS synthesis, the coupling mechanism between the LOS angular velocity of the two frame seeker and the roll angular velocity of the missile is analyzed. In order to eliminate the coupling effect, the Kalman filter technology is used to extract the LOS angular velocity, and the Kalman filter equation is established, which is verified by simulation. The results show that the missile roll movement affects the gyro output, and the extraction of LOS angular velocity by Kalman filter technology can meet the requirements of guidance information accuracy.
Gait Planning of Quadruped Robot Based on ROS

The development of quadruped robot platforms is a relatively active area of scientific research. Taking into account the intuitiveness and high efficiency of the robot development process, the robot development method based on ROS(Robot Operating System) is adopted. First, the kinematics modeling of the quadruped robot is carried out, and the robot kinematics is solved. Secondly, the basic principles of walking gait planning for quadruped robots are introduced. The trajectory planning method based on Cartesian space is used to plan the trajectory of the quadruped robot's foot, and it is simulated and verified by Matlab. Finally, the quadruped robot model file is imported into ROS, and the gait planning control program of the quadruped robot is written through the user's API for motion planning simulation. At the same time, RViz can visualize the robot movement process, and obtain other relevant data during the movement process, indicating the correctness of the trajectory planning. The results show that the development method of quadruped robot based on ROS is feasible.
95GHz 13dBm IQ-combined PA in 65nm CMOS

A 88-100GHz stand-alone power amplifier and a 95-100GHz IQ combined power amplifier in 65-nm bulk CMOS are reported. The single PA is a 3-stage pseudo-differential CS design with transformers as matching networks, utilizing cross-coupled capacitive neutralization. The IQ PA utilizes the single PA core and uses a current combiner to sum two quadrature signals at the output. The single PA achieves 13.4 dBm saturated power with peak PAE of 11.6%. The IQ PA achieves 13 dBm of output power in QPSK constellations and offers a 360° phase control. Both designs use a 1.2 V supply.
Design and Optimization of a Full Duplex CSMA/CA Medium Access Mechanism for Hybrid Visible Light Communication Networks

Visible Light Communications (VLC) is emerging as an appealing technology to complement WiFi in indoor environments. In this paper, we propose a CSMA/CA based full duplex MAC protocol FD-CSMA/CA for hybrid VLC networks which use infrared light as uplink channel. We also propose an optimization mechanism ERTS to return CTS frame with RTS frame in parallel, which reduces the uplink collision possibility and improves the uplink throughput. We build a hybrid VLC network testbed and implement the full duplex MAC protocol in the linux kernel network stack. Performance evaluation shows the proposed MAC protocol throughput is improved about 85% in a three nodes network compared to the original CSMA/CA protocol.