Miracle-dz/UniFAR-FTUs huggingface dataset:
A Survey of End-to-End Solutions for Reliable Low-Latency Communications in 5G Networks

Very low latency and high reliability are two of the main requirements for new applications exploiting 5G networks. This is the case for the remote operation of robots or vehicles, the autonomous interaction of equipment in a factory, autonomous driving and tactile internet applications. Although the TCP/IP stack has been sufficient as the end-to-end solution for most of the history of the Internet, a number of surveys have appeared recently presenting many different methods for managing the end-to-end communication to meet the requirements of various technologies such as that of 5G networks. In this paper, we present a novel classification of the literature focused on new end-to-end solutions and the creation of services towards the support of low latency (1 ms) and high reliability (10−9 error rate) in current and future 5G networks. We specifically highlight how the proposals can be classified according to enabling technologies and the specific method used to achieve success in terms of the latency and reliability. The literature related to end-to-end solutions for reliable low-latency communications are organized according to three main topics: (i) end-to-end protocols that improve communication in terms of latency and reliability, (ii) functionality or technologies implemented on the network to support the current demands, and (iii) application programming interfaces that enhance the correct utilization of those protocols and additional technologies.
AxFTL: Exploiting Error Tolerance for Extending Lifetime of NAND Flash Storage

NAND flash storage has become a standard choice in consumer electronics and is gaining popularity in enterprise systems due to its superior performance and low-power consumption. While its cost disadvantage is rapidly fading thanks to multibit cell technologies and 3-D stacking architectures, the challenge of limited endurance is still lingering and is expected to become more daunting as bits-per-cell continues to increase. In this article, we propose a novel flash translation layer (FTL) design named AxFTL (Approximate FTL) that extends the lifetime of NAND flash storage for error-tolerant applications. For error-tolerant data, AxFTL adopts shallow erase that lowers erase voltage to reduce the erase-induced wearing at the cost of an increased error rate. AxFTL manages multiple groups of blocks by error rates and allocates them according to the error tolerance of write requests. The key components of AxFTL include error tolerance-aware garbage collection and wear leveling schemes that manage the blocks with different error rates with minimal overhead. We implement AxFTL in an SSD simulator for the evaluation of the lifetime improvement and the actual allocation of the blocks. For application-level evaluation, we apply AxFTL to compressed video storage and evaluate the quality of video playback. Our experimental results show that AxFTL greatly improves the lifetime of NAND flash storage by 61% while maintaining a high structural similarity (SSIM) of 0.86 as compared to the conventional FTL.
Self-supervised Pairing Image Clustering and Its Application in Cyber Manufacturing

Artificial intelligence is being increasingly applied in manufacturing to maximize industrial productivity. Image clustering, as a fundamental research direction in unsupervised learning, has been used in various fields. Since no label information is required in clustering, it can perform a preliminary analysis of the data while saving lots of manpower. In this paper, we propose a novel end-to-end clustering network called Self-supervised Pairing Image Clustering (SPIC) for industrial application, which produces clustering prediction for input images in an advanced pair classification network. For training this network, a self-supervised pairing module is built to form balanced pairs accurately and efficiently without label information. Since the existence of trivial solutions cannot be avoided in most of unsupervised learning methods, two additional information theoretic-constraints regularize the training that ensures the clustering prediction to be unambiguous and close to the real data distribution during training. Experimental results indicate that the proposed SPIC outperforms the state-of-art approaches on manufacturing datasets–NEU and DAGM. It also shows the execellent generalization capability on other genral public datasets, such as MNIST, Omniglot, CIFAR10, and CIFAR100.
Two-Stage Optimal Sizing of Standalone Hybrid Electricity Systems with Time-of-Use Incentive Demand Response

This paper presents a two-stage optimization technique in sizing various components of standalone hybrid electricity systems with time-of-use (ToU) incentive demand response program. In the first stage of optimization, the minimum levelized cost of electricity (LCOE) is determined without using demand response. The result of the first stage (LCOE) is used as a base rate to develop a ToU demand response for incentive payment in the second stage of optimization. In developing the incentive payment, three periods of a day (off-peak, shoulder, and peak) with different payment rates of electricity are considered. Five different standalone system configurations are developed using various combinations of diesel generators, wind generators, solar photovoltaics, battery energy storages, and flywheels. The proposed two-stage optimization technique is then applied to all five configurations of a remote area South Australian community. Real yearly data of electricity consumption, solar radiation, wind speed, and air temperature, as well as real market price of the components are used in the optimization. It has been found that the hybrid standalone system consisting of diesel, solar, wind, and battery has the minimum overall cost of electricity.
A Medium Voltage Dual Active Bridge Converter based on Gen-3 10 kV SiC MOSFETs

Wide bandgap based medium voltage power semiconductor devices have opened up a multitude of opportunities for medium-voltage converters in power transmission and distribution. In addition to low on-state resistance, compared to its silicon counterparts, the fast switching capability of these devices has made it possible for medium voltage converter operation at high frequencies. This helps in the reduction in the size and weight of the magnetic components. A Mobile Utility Support Equipment based three-phase Solid-State Transformer (MUSE-SST) system is developed at FREEDM Systems Center to interconnect a three-phase 4160 V grid to a three-phase 480 V grid. The MUSE-SST system consists of three power conversion stages, to establish isolated grid interconnection, namely MVac/MVdc stage (MV Active front end converter), MVdc/LVdc stage (Dual active bridge converter), and LVdc/LVac stage (LV Active front end converter). Galvanic isolation is introduced in the MVdc/LVdc stage using an MV-LV high-frequency transformer. This paper discusses the modeling of the parasitic elements and characterization of the high-frequency transformer. A SPICE model is developed to emulate the parasitic elements of the high-frequency transformer. Experimental results validating the operation of the high-frequency transformer are provided. The medium voltage dual active bridge converter, which forms the MVdc/LVdc stage of the MUSE-SST system, is also discussed and experimental results demonstrating the operation and feasibility of the medium voltage dual active bridge converter are shown.
Overload Performance Prediction of PM and Synchronous Reluctance Machines for Traction Applications

This paper proposes several methods to compare the overload performance of different types of synchronous machines for electric traction applications. An ideal model to predict the performance of the motor at high overload condition is introduced. In the simplified analytical saturation model, the saturation flux linkage is a parameter. This allows the performance prediction as a function of three normalized parameters: magnet flux linkage, unsaturated inductance and saliency ratio.The other main part of the work concerns the machines analysis using the finite element approach. Models with different levels of accuracy and generality show the possibility of reducing the number of simulations in the d- and q-axis currents plane to obtain the full performance prediction. Machines with different level of cross saturation are considered to test the proposed models.Simulation results of the studied approaches are compared with the prediction obtained from the full machine mapping using finite element analysis, in which a large number of evenly spaced points in the (id,iq) plane are analyzed to derive the working characteristics.
A Simple Carrier-Based Implementation for a General 3-level Inverter Using Nearest Three Space Vector PWM Approach

This paper proposes a novel carrier-based implementation strategy of a standard space-vector pulse-width modulation (SVPWM) technique of three-phase (3ϕ) three-level inverter (TLI). To synthesize the reference voltage vector, the selected SVPWM technique uses nearest three voltage space-vectors in order to reduce output voltage THD and partially balance the neutral point voltage. The implementation complexity of this SVPWM technique is reduced by introducing the concept of common-mode signal in duty-ratio calculation of 3ϕ-TLI. Following the modulation strategy of the selected SVPWM technique, general expression of common-mode signal has been derived in terms of maximum, middle and minimum values of input 3ϕ modulation signals. It is shown in the paper that six duty ratios of 3ϕ-TLI can be directly calculated from the input 3ϕ modulation signals and the derived common-mode signal. Thus, calculation-intensive steps of SVPWM technique, like, identification of reference voltage vector location, calculation of dwell-times of individual vectors, are avoided. The proposed algorithm is validated through simulation in MATLAB and experiment on 1.5 kW hardware prototype.
Current Harmonic Analysis of Multisampled LCLType Grid-connected Inverter

Multisampling control provides an attractive way to reduce the control delays in LCL-type grid-connected inverters, and thereby the bandwidth and stability margin will be improved. However, high frequency switching harmonics is introduced in the control loop when the inverter current is selected as a feedback. In order to investigate the effect of high frequency switching harmonics, the internal relationship between double-update pulse width modulation (PWM) and four-update PWM is deduced through the geometric analysis. Compared with the double-update PWM, a sampling instant is shifted a quarter of the switching period during each switching period. Hence the non-average value is sampled and low-order aliased harmonics will appear in the grid current. Finally, the theoretical analysis is verified through the simulation and experimental results.
Power IGBT Remaining Useful Life Estimation Using Neural Networks based Feature Reduction

Power converters (PCVs) are a fundamental part of wind energy systems (WESs). Generally, the PCVs are subjected to high failure frequency rate and consequently to the system downtime due to its structural complexity. Therefore, the main propose of this study is to develop an understanding prognostic approach dedicated to WES PCVs. The proposed method investigated the Insulated Gate Bipolar Transistor (IGBT) failure in PCVs. Therefore, it integrates the data-based methodology. Usually, data-based approaches based on a recorded data base. Therefore, in this paper, we use the collectoremitter voltage as a precursor signal. In this work, the prediction of the Remaining Useful Life (RUL) of the IGBT device is achieved through the Feedforward Neural Network (FFNN) technique. Moreover, we used the time-domain analysis to extract useful information used as an input in the health indicator generation task. In this paper, the health indicator generation task is achieved using the Principal Component Analysis (PCA) technique. The advantages of the proposed prognostic method in term of RUL prediction are illustrated using a real IGBT accelerated ageing database provided from NASA Ames laboratory Prognostics Center of Excellence.
Switched Capacitor MMC Submodule Voltage Balancing with Reduced Number of Voltage Sensors

This paper presents a submodule (SM) capacitor voltage balancing scheme for the Switched Capacitor Modular Multilevel Converter (SC-MMC), which employs a middle submodule connecting the upper and lower arms and does not require large physical arm inductors. Only small stray/parasitic inductance is enough to limit inrush current during SM’s switching instants. This topology is directly derived from the generalized multilevel converter. The SC-MMC has the benefit of providing the same number of output voltage levels than the conventional MMC using one less submodule per phase leg. A Y-matrix modulation (YMM) that guarantees automatic SM capacitor balance without any SM feedback voltage has been proposed for an MMC topology with extremely low arm inductance. It is shown here, that the direct application of YMM cannot achieve automatic capacitor balancing for SC-MMC with middle SM. Thus, a strategy based on a modified Y-matrix modulation that requires only sensing and feedback of the middle SM voltage and output current is proposed to ensure balancing of all SM capacitor voltages. Simulation of a 6-level SC-MMC is provided to verify the voltage balancing capability with proposed control in steady state and transient conditions.
Design for Reliability of SiC-MOSFET-Based 1500-V PV Inverters with Variable Gate Resistance

500-V Photovoltaic (PV) inverters are becoming the mainstream in solar PV industry. Extending the maximum DC voltage from 1000 V to 1500 V can reduce the installation cost of PV power plants. However, it may negatively affect the reliability of the corresponding PV inverters, due to the increased loading stresses, i.e., voltage stress and thermal loading of power devices. In this context, this paper investigates the potential to enhance the reliability of SiC-MOSFET-based 1500-V PV inverters through the design of the gate resistance, considering the switching overshoot and the stray inductance in the commutation loops. The impact of switching speed on the inverter reliability is analyzed with the mission profile of a 125-kW/1500-V PV system (interfacing the grid with a SiC-based two-level inverter) installed in Denmark. The evaluation results indicate that the PV inverter with the proposed design (i.e., variable gate resistance) can achieve a better reliability performance than that with fixed gate resistance and ensure a safer operating voltage margin.
A study of high electrical power and high efficiency antenna in 13.56 MHz Wireless Power Transfer

Wireless Power Transfer (WPT) has been attracting attention as one of the solutions of EV charging. In recent years, many researches have used the kHz band, however the size of antenna becomes large. To solve the sizing problem, using industrial, scientific, and medical (ISM) bands;13.56MHz is a good solution. However, the example of antenna design which achieve high efficiency about 90% with over 200mm transfer distance has not been reported. In addition, there is no report of high power transmission over 1kW. In this paper, an antenna design method is proposed and the method is experimentally confirmed. In addition, this prototype antenna can transfer about 2.5kW electrical power with 89.3% antenna efficiency under 300mm transmission distance in the experiment.
Laboratory Studies of Atmospheric Reactions Using Infrared Cavity Ringdown Spectroscopy

Infrared cavity ringdown spectroscopy provides for sensitive spectroscopic detection with a time scale of microseconds. This thesis discusses the implementation of infrared cavity ringdown spectroscopy for studies of atmospheric reactions. Chapter 1 details the infrared cavity ringdown spectrometer assembled in our laboratory. Pulsed infrared radiation was generated by pumping an optical parametric amplifier (OPA) with 532 nm light from a doubled Nd:YAG laser, and a tunable dye laser provided the signal frequency. The ringdown decay was fit to an exponential curve to extract a ringdown time from which concentrations of absorbing species could be determined. Initial measurements indicated that our apparatus is a highly sensitive spectroscopic probe of infrared transitions of molecules with absorption linewidths greater than 1 cm^(-1). Our detection limit for the j = 7 line of the v_3 band of methane in a 43 inch cell was 10^(13) molec/cc of methane. Chapter 2 describes initial kinetics experiments performed with our apparatus for the reactions of HO_2 + HO_2 and HO_2 + ClO. Our results for the rates of the HO_2 + HO_2 reaction and the HO_2 + ClO reaction agree well with literature values, demonstrating the capabilities of our system for use in kinetic studies. We were unable to observe the formation of the postulated HOOOCI intermediate from the reaction of HO_2 + ClO due to spectral interference from H_2O_2 in the region where HOOOCl is predicted to absorb. Chapter 3 discusses studies of the reaction pathways undergone by alkoxy radicals. We found that photolysis of the alkyl nitrite precursor at 248 nm resulted in an unexpectedly high rate of decomposition of the alkoxy radicals, and we attributed this result to excess energy in the alkoxy radicals following photolysis at this wavelength. With photolysis at 351 nm, no decomposition products were detected. At this wavelength, we observed an -OH peak at 3675 cm^(-1) for the n-butoxy and n-pentoxy radicals, which is evidence of the isomerization channel. For the n-butoxy radical, we determined that the ratio of the rate for its reaction with O_2 versus its isomerization (k_(O2)/k_(isom)) was (4.0±0.1)*10^(-20) cm^3 molec^(-1) when probing the isomerization product milliseconds after the generation of the n-butoxy molecule and (3.6±1.4)* 10^(-20) cm^3 molec^(-1) when probing the isomerization product 10-20 µs after the generation of the nbutoxy radical. For the n-pentoxy radical, we placed an upper limit on the ratio of k_ (O2)/k_(isom) of 5.6*10^(-21) cm^3 molec^(-1).
Combating Enhanced Thermal Covert Channel in Multi-/Many-Core Systems With Channel-Aware Jamming

As a means to thwart thermal covert channel attack in a multi-/many-core system, a strong heat noise whose frequency band coincides with that occupied by the thermal covert channel is injected to jam the channel. However, this undiscriminating channel jamming-based countermeasure will fail if a thermal covert channel is allowed to change its transmission frequency dynamically in response to the jamming. To combat this enhanced thermal covert channel, a more advanced countermeasure is needed and thus proposed that checks the frequency spectrum and tracks any possible covert channel. Only after a channel is detected to be susceptible, a thermal noise with this channel frequency is then emitted to jam the covert channel. The communication protocols and frequency changing scheme pertaining to this enhanced thermal covert channel are described in this article. The experimental results confirm that, when the proposed countermeasure is applied, the enhanced thermal covert channel, much more resilient to jamming, suffers from an extremely high packet error rate (PER), which makes any meaningful data leakage practically impossible. As the proposed countermeasure method is poised to contain dangerous thermal covert channel attacks with an anti-jamming capability, it lends itself well to secure multi-/many-core systems.
Development of a Hybrid Cascaded Converter based STATCOM with Reduced Switching Losses

This paper develops a static synchronous compensator (STATCOM) based on the hybrid cascaded converter. A hybrid modulation scheme is employed in the hybrid cascaded converter to reduce the switching losses while maintaining the output performance, and the corresponding dc capacitor voltage balancing control scheme is proposed. The laboratory test results are provided to verify the feasibility of the developed STATCOM.
Design and Implementation of Paralleled Inverters with LCLC Resonant Tanks to Generate Plasma for Surface Treatment Applications

This paper presents design and implementation of paralleled inverters with LCLC resonant tanks to generate plasma source for material-surface-treatment. The proposed multi-inverter system consists of two inverters with their outputs connected to the same load. Based on sensitivity analysis, the configuration of an LCLC resonant tank has been determined for the inverters, resulting in less sensitivity to component variation as compared to a conventional LC tank. Phase-shift control for each inverter and phase-difference control between the inverters are adopted to achieve identical output currents. Simulated and experimental results of a two-module LCLC inverter system with load variations and modular discrepancy have demonstrated the discussions and analyses.
Sensorless Capacity Evaluation of a New Five-phase Flux-Intensifying Fault-Tolerant Interior-Permanent-Magnet Motor

To improve sensorless operating performance of motor drive system, most existing researches are investigated from the perspective of control algorithm improvement, which will increase the complexity of the drive controller. In this paper, a new five-phase flux-intensifying fault-tolerant interior-permanent-magnet (FIFT-IPM) motor is proposed from the perspective of motor system design. Due to the appropriate inductance characteristics, the proposed FIFT-IPM motor is suitable for sensorless operation. Also, its sensorless operating capacity including low-speed, medium/high-speed, normal and fault operating condition is evaluated. With the special design to obtain the inductance characteristic of adverse saliency with Ld > Lq and the little inductance variation under different operating conditions, the good sensorless capacity of the proposed motor can be achieved. Furthermore, the good sensorless operating performances of the proposed motor are validated by simulation results.
Optimized Cascaded Controller Design for a 10 kW / 100 kHz Large Signal Bandwidth AC Power Source

The control system of a phase-modular three-phase 10 kW / 230 Vrms Ultra-High bandwidth series/parallel inter-leaved multi-level AC Power Source (UHPS) for P-HIL applications with 4.8 MHz effective switching frequency is optimized with respect to high bandwidth and low output impedance or output admittance (depending on whether output voltage or output current is controlled), by adding selected and effective enhancements to existing control structures. The theoretical findings are verified by means of a detailed simulation model, which also takes time-discretization effects arising from the FPGA-based digital control unit into account. The comparative evaluation of the investigated control structures reveals that the combination of capacitor current feedback, inductor voltage feed-forward, and reference prediction performs best for the control of both, output voltage and output current. In this regard, at 100 kHz and for operation with rated load resistance of 5.3 Ω, the phase-lag of the output voltage of the optimized voltage control system can be reduced from 19°, for the conventional two-loop control structure, to 7°; the small-signal bandwidth increases from 235 kHz to 427 kHz; and the output impedance at 100 kHz decreases from 0.6 Ω to 143 mΩ. In case of output current control, at an output frequency of 60 kHz, and for rated load resistance, the phase-lag of the output current can be reduced from 51° to 33°, for an optimized three-loop control structure, which is accompanied by an increase of the small-signal bandwidth from 63 kHz to 89 kHz and an increase of the output impedance from 11 Ω to 30 Ω at 60 kHz.