Miracle-dz/UniFAR-FTUs huggingface dataset:
Precedence-Aware Automated Competitive Analysis of Real-Time Scheduling

We consider a real-time setting where an environment releases sequences of firm-deadline tasks, and an online scheduler chooses on-the-fly the ones to execute on a single processor so as to maximize cumulated utility. The competitive ratio is a well-known performance measure for the scheduler: it gives the worst-case ratio, among all possible choices for the environment, of the cumulated utility of the online scheduler versus an offline scheduler that knows these choices in advance. Traditionally, competitive analysis is performed by hand, while automated techniques are rare and only handle static environments with independent tasks. We present a quantitative-verification framework for precedence-aware competitive analysis, where task releases may depend on preceding scheduling choices, i.e., the environment can respond to scheduling decisions dynamically. We consider two general classes of precedences: 1) follower precedences force the release of a dependent task upon the completion of a set of precursor tasks, while and 2) pairing precedences modify the characteristics of a dependent task provided the completion of a set of precursor tasks. Precedences make competitive analysis challenging, as the online and offline schedulers operate on diverging sequences. We make a formal presentation of our framework, and use a GPU-based implementation to analyze ten well-known schedulers on precedence-based application examples taken from the existing literature: 1) a handshake protocol (HP); 2) network packet-switching; 3) query scheduling (QS); and 4) a sporadic-interrupt setting. Our experimental results show that precedences and task parameters can vary drastically the best scheduler. Our framework thus supports application designers in choosing the best scheduler among a given set automatically.
A comparative study of maximum power point tracking algorithms for PV arrays

Renewable energy sources like the sun have great potential to change the energy sector. Photovoltaic arrays are required to harness this energy; however, obtaining maximum power from the arrays has always been a challenge. Several authors have proposed different maximum power tracking (MPPT) algorithms. This paper presents a comparative study between the Incremental Conductance and Perturb & Observe MPPT to find the most efficient and effective algorithm at any irradiance and temperature. Simulation and experimentation were conducted with results analyzed and compared. From the analysis, the general observation emerges that the Incremental conductance algorithm is the best performing.
Experimental Test on Dual Three-Phase Synchronous Reluctance Motor

This study investigates experimental test on 8-pole 36-slot dual three-phase synchronous reluctance motor according to different two winding configurations. The characteristics of motor for the two winding configurations were analyzed by changing the winding distribution of two three-phase system. The experiment was carried out using one three-phase inverter instead of two inverters for the convenience of experiment since this paper deals with the symmetric models The flux and torque characteristics are analyzed according to different dq-axis currents under healthy and half control mode conditions. In addition, torque and power versus speed characteristics are analyzed under half control and short-circuit modes.
Model-Free Predictive Current Control of PWM Rectifier Under Unbalanced and Distorted Network

Model predictive current control (MPCC) has been proposed for the control of a pulse width modulation (PWM) rectifier due to its simple principle and quick response. MPCC achieves good performance for ideal grid voltages when an accurate inductance value is known. However, the actual grid voltages are usually unbalanced and distorted, and the inductance may vary with the working condition. In these conditions, the performance of a PWM rectifier deteriorates significantly due to the current harmonics and power ripples. To cope with distorted grid voltages and inductance variations, this paper proposes model-free predictive current control (MFPCC) for a PWM rectifier, which can achieve sinusoidal grid currents and a constant active power even under an unbalanced and distorted network. The robustness against an inductance variation is achieved by using an extended state observer (ESO) based on an ultralocal model of the system. The current reference is calculated based on the principle of active power ripple elimination and then is tracked by predictive control. The presented experimental results prove that the proposed MFPCC scheme achieves good performance under a distorted network even with an inaccurate inductance value.
Measurement of Rotor Thermal Time-Constant for Permanent Magnet Synchronous Machines

Thanks to their high torque density, permanent magnet synchronous motors (PMSMs) currently represent the most competitive solution in the electrification processes involving transports and energy production. However, it is known how the torque production of such motors is strictly related to the temperature of the permanent magnet (PM), affecting control performance, and efficiency. This issue makes necessary the thermal analysis of the machine, thus requiring the determination of the PM’s thermal time-constant. In this paper, an experimental method for evaluating such a parameter is proposed, allowing high accuracy and reliability of the result. The proposed procedure can be applied to any PMSM type, without being affected by factors such as rotor lamination, shaft, PM distribution. The experimental validation has been carried out on three PMSMs, having different rotor structure, sizes, and voltage/current levels. Experimental results demonstrate the validity of the proposed method.
Optimization of Intercache Traffic Entanglement in Tagless Caches With Tiling Opportunities

So-called “tagless” caches have become common as a means to deal with the vast L4 last-level caches (LLCs) enabled by increasing device density, emerging memory technologies, and advanced integration capabilities (e.g., 3-D). Tagless schemes often result in intercache entanglement between tagless cache (L4) and the cache (L3) stewarding its metadata. We explore new cache organization policies that mitigate overheads stemming from the intercache-level replacement entanglement. We incorporate support for explicit tiling shapes that can better match software access patterns to improve the spatial and temporal locality of large block allocations in many essential computational kernels. To address entanglement overheads and pathologies, we propose new replacement policies and energy-friendly mechanisms for tagless LLCs, such as restricted block caching (RBC) and victim tag buffer caching (VBC) to incorporate L4 eviction costs into L3 replacement decisions efficiently. We evaluate our schemes on a range of linear algebra kernels that are software tiled. RBC and VBC demonstrate a reduction in memory traffic of 83/4.4/67% and 69/35.5/76% for 8/32/64 MB L4s, respectively. Besides, RBC and VBC provide speedups of 16/0.3/0.6% and 15.7/1.8/0.8%, respectively, for systems with 8/32/64 MB L4, over a tagless cache with an LRU policy in the L3. We also show that matching the shape of the hardware allocation for each tagless region superblocks to the access order of the software tile improves latency by 13.4% over the baseline tagless cache with reductions in memory traffic of 51% over linear superblocks.
Robust Image Feature Extraction via Approximate Orthogonal Low-Rank Embedding

Feature extraction (FE) plays an important role in machine learning. In order to handle the “dimensionality disaster” problem, the usual approach is to transform the original sample into a low-dimensional target space, in which the FE task is performed. However, the data in reality will always be corrupted by various noises or interfered by outliers, making the task of feature extraction extremely challenging. Thence, we propose a novel image FE method via approximate orthogonal low-rank embedding (AOLRE), which adopts an orthogonal matrix to reserve the major energy of the samples, and the introduction of the $\ell _{2,1}$ -norm makes the features more compact, differentiated and interpretable. In addition, the weighted Schatten ${p}$ -norm is adopted in this model for fully exploring the effects of different ranks while approaching the original hypothesis of low rank. Meanwhile, as a robust measure, the correntropy is applied in AOLRE. This can effectively suppress the adverse influences of contaminated data and enhance the robustness of the algorithm. Finally, the introduction of the classification loss item allows our model to effectively fit the supervised scene. Five common datasets are used to evaluate the performance of AOLRE. The results show that the recognition accuracy and robustness of AOLRE are significantly better than those of several advanced FE algorithms, and the improvement rate ranges from 2% to 15%.
A Seven-Level Switched Capacitor Inverter Using Series/Parallel Conversion with Reduced Number of Switches

This paper proposes a new seven-level inverter for PV-module-integrated single-phase inverters. The proposed circuit consists of an h-bridge inverter with a switched-capacitor step-up converter. The switched capacitor converter supplies a three-level voltage to the input terminal of the h-bridge inverter and thus the line-to-line voltage of the h-bridge inverter becomes 7 levels. This makes it possible to reduce the switching ripple in the ac current resulting in the reduction of the ac filter capacity. Also, level-and phase-shifted pulse-width modulation is applied to this inverter. This PWM method enables the reduction of the voltage ripple of the switched capacitors hence small capacitance. Finally, this paper confirms the validity of the proposed circuit and the PWM methods using an experimental system.
A Dynamic Artificial Potential Field (D-APF) UAV Path Planning Technique for Following Ground Moving Targets

Path planning is a vital and challenging component in the support of Unmanned Aerial Vehicles (UAVs) and their deployment in autonomous missions, such as following ground moving target. Few attempts are reported in the literature on multirotor UAV path planning techniques for following ground moving targets despite the great improvement in their control dynamics, flying behaviors and hardware specifications. These attempts suffer several drawbacks including their hardware dependency, high computational requirements, inability to handle obstacles and dynamic environments in addition to their low performance regarding the moving target speed variations. In this paper, a novel dynamic Artificial Potential Field (D-APF) path planning technique is developed for multirotor UAVs for following ground moving targets. The UAV produced path is a smooth and flyable path suitable to dynamic environments with obstacles and can handle different motion profiles for the ground moving target including change in speed and direction. Additionally, the proposed path planning technique effectively supports UAVs following ground moving targets while maneuvering ahead and at a standoff distance from the target. It is hardware-independent where it can be used on most types of multirotor UAVs with an autopilot flight controller and basic sensors for distance measurements. The developed path planning technique is tested and validated against existing general potential field techniques for different simulation scenarios in ROS and gazebo-supported PX4-SITL. Simulation results show that the proposed D-APF is better suited for UAV path planning for following moving ground targets compared to existing general APFs. In addition, it outperforms the general APFs as it is more suitable for UAVs flying in environments with dynamic and unknown obstacles.
High Performance Texture Streaming and Rendering of Large Textured 3D Cities

We introduce a novel, high performing, bandwidth-aware texture streaming system for progressive texturing of buildings in large 3D cities, with optional texture pre-processing. We seek to maintain high and consistent texture streaming performance across different city datasets, and to address the high memory binding latency in hardware virtual textures. We adopt the sparse partially-resident image to cache mesh textures at runtime and propose to allocate memory persistently, based on mesh visibility weightings and estimated GPU bandwidth. We also retain high quality rendering by minimizing texture pop-ins when transitioning between texture mipmaps. We evaluate our texture streaming system on large city datasets, including a tile-based dataset with 56K large atlases and a dataset containing 5.7M individual textures. Results indicate fast and robust streaming and rendering performance with minimal pop-in artifacts suitable for real-time rendering of large 3D cities.
Metal Coated Fabric Based Supercapacitors

This work reports the fabric-based supercapacitors (FSCs) using silver coated textile as the current collector. The electrochemical properties of the device in PVA-KCl gel electrolyte was studied. The performance of the device was further improved by printing an inhouse formulated graphite paste as the active electrode. The graphite printed Berlin fabric-based supercapacitor (BGr-FSC) shows an areal capacitance (CA) of 13.1 mF.cm−2, which is almost 4 times higher than the capacitance (3.53 mF.cm−2) of Berlin based FSC i.e. the one without graphite paste.
Comparison of Two Hollow-Shaft Liquid Cooling Methods for High Speed Permanent Magnet Synchronous Machines

The rotor cooling poses a significant challenge for high speed permanent magnet synchronous machines (PMSMs). This paper presents a recirculating hollow-shaft liquid cooling structure. Through the computational fluid dynamics (CFD) method, its convective heat transfer coefficient (CHTC) and friction loss are studied in depth. Besides, the recirculating hollow-shaft is compared with the direct-through hollow-shaft. Based on the CFD analysis, it is found that the recirculating hollow-shaft has higher friction loss. But the CHTC of the recirculating hollow-shaft is higher than that of the direct-through hollow-shaft, which can be as high as 32%. Finally, the cone-shaped structure and blade structure are used to optimize the recirculating hollow-shaft, increasing its CHTC by 49%. The cooling effect of the optimized recirculating hollow-shaft structure is more prominent, especially when the rotor loss is large.
Frequency Scanning-Based Contributions Identification of Current Control Loop and PLL on DQ Impedance Characteristics of Three-Phase Grid-Connected Inverter

Complex space vector and complex transfer function theory is used to theoretically establish the dq impedance model of current-controlled grid-connected inverter (GCI) with considering phase-locked loop (PLL) dynamics, where contributions of current control loop and PLL on dq impedance characteristics are clearly identified. On its basis, this paper presents a frequency scanning-based black box identification method of the contributions of current control loop and PLL on dq-domain impedance characteristics of the GCI. Three-phase small-signal voltage vector perturbation which is aligned with point of common coupling (PCC) voltage vector is injected into PCC in series way, so that grid current responses which are only determined by the dynamics of current control loop are excited. In addition, parallel current injection to excite PCC voltage responses is theoretically proved to be not applicable for extracting the dynamics of current control loop and PLL. The effectiveness of the presented dq-domain impedance characteristics division method is verified by both frequency scanning results and time-domain simulation results obtained in Matlab/Simulink environment.
Design of Archimedes Spiral Antenna to Optimize for Partial Discharge Detection of Inverter Fed Motor Insulation

The partial discharge (PD) in inverter-fed motors generated from high frequency and short rise time impulsive voltage are more complex than traditional sinusoidal voltage operated motors due to the noise initiated from fast switching power electronics devices. Available PD sensors and related technology for DC and sinusoidal voltage cannot be used at repetitive impulsive voltage conditions. This work aims to report the design of antenna with optimized geometry and satisfied parameters to detect PD for impulsive voltage. The antenna is verified and the influence of both impulse voltage parameters and test configuration on PD features are discussed. The envelope detection technique after the filter in the frequency domain was proposed to reduce the complexity and cost of PD test hardware under impulsive voltages with fast rise times. The frequency domain energy of PD from motor insulation is mainly distributed in the range of 0.6-1.8 GHz. By increasing the amplitude and frequency of input impulsive voltage, the range of PD energy spectrum is enlarged to (1.5-1.8 GHz) and by decreasing input amplitude the PD signal strength decays abruptly. Moreover, the high-frequency distribution of PD energy attenuates more severely with the distance and the electromagnetic energy of PD decays nonlinearly with the increase of propagation distance. Therefore, under the premise of satisfying the safety test, selecting the test distance below 15 cm can ensure that the test results have a high signal-to-noise ratio and signal integrity. The experience reported in this study could provide suggestions for off-line PD measurements for inverter-fed motor insulation evaluations for manufacturers.
Design and Optimization of a Highly Integrated Modular Filter Building Block for Three-Level Grid Tied Converters

With the advent of high power SiC devices, interleaving of converters offers benefits from high power density and efficiency point of view. One major advantage is low filter size requirement to meet THD and current harmonic levels compared to a single converter or hard paralleled converters. However, additional magnetic components are needed to mitigate the problem of circulating current between multiple converters which contribute to additional semiconductor and filter loss. In addition, there is a need for a modular filter architecture that can handle circulation and meet THD irrespective of the number of channels. Not to mention, the need for conducted emissions compliance, which is a key essence of modularity as the number of converters are scaled in parallel. Such an integrated filter block does not exist in current literature and is proposed in this paper. A detailed design and optimization procedure is presented to maximize efficiency and power density of this modular filter building block and the associated converter. A 5.8 kW/liter prototype of a three-channel interleaved 15 kW 3L-NPC converter is evaluated for up to three channels.
Glutamate's Role in a Visceral Sympathoexcitatory Reflex in Rostral Ventrolateral Medulla of Cats

The rostral ventral lateral medulla (rVLM) is involved in processing visceral sympathetic reflexes. However, there is little information on specific neurotransmitters in this brain stem region involved in this reflex. The present study investigated the importance of glutamate and glutamatergic receptors in the rVLM during gallbladder stimulation with bradykinin (BK) since glutamate is thought to function as an excitatory neurotransmitter in this region. Stimulation of visceral afferents activated glutamatergic neurons in the rVLM, as noted by double-labeling with c-Fos and the cellular glutamate transporter, VGLUT3. Visceral reflex activation significantly increased arterial blood pressure as well as extracellular glutamate concentrations in the rVLM as determined by microdialysis. Barodenervation did not alter the release of glutamate in the rVLM evoked by visceral reflex stimulation. Iontophoresis of glutamate into the rVLM enhanced the activity of sympathetic premotor cardiovascular rVLM neurons. Also, the responses of these neurons to visceral afferent stimulation with BK were attenuated significantly (70%) by blockade of glutamatergic receptors with kynurenic acid. Microinjection of either an NMDA receptor antagonist AP-5 (25 mM, 30 nl) or an AMPA receptor antagonist CNQX (2 mM, 30 nl) into the rVLM significantly attenuated the visceral sympathoexcitatory reflex responses. These results suggest that glutamate in the rVLM serves as an excitatory neurotransmitter through a baroreflex-independent mechanism, and that both NMDA and AMPA receptors mediate the visceral sympathoexcitatory reflex responses.
An Inductive Power Transfer System using Soft-Switched AC/AC Active-Clamped Half-Bridge Converter with Predictive Dead-Beat Grid Current Control

In this paper, a dead-beat control-based AC/AC active-clamped half-bridge (HB) converter feeding inductive wireless charging system is presented. It offers some advantages of a low component count, high efficiency, reliability, cost-effectiveness, and unity power factor. The system design procedure and non-linear dead-beat controller development are given in detail. The main drawbacks of the AC/AC active-clamped HB converter are the high current stress and hard switching of the lower switches. In this paper, the all-switch zero-voltage-switching (ZVS) operation of the AC/AC active-clamped HB converter based inductive wireless charging system is explored. Moreover, the performance of the charging system under the variation of the mutual inductance and compensation capacitors are evaluated. Simulation and experimental results are given to verify the theoretical analysis.
Conducted EMI Reduction in Boost Converter Using dsPIC Based Chaotic Pulse Position Modulation Technique

Chaotic PWM control is a new emergent method for suppressing conducted electromagnetic interference (EMI) generated by the dc-dc power converter. It effectively suppresses the peaky harmonics by spreading it all around the central frequency in the desired wide frequency band. Thus the EMI spectrum is smoothed and flattened with a reduced EMI noise level. The current paper presents a chaotic Pulse Position Modulation (PPM) technique based on the Logistic map. It is generated digitally through a dsPIC microcontroller. Then, it is applied to a boost converter to reduce the conducted EMI generated within. Looking for accuracy, an electromagnetic (EM) prototype of the boost converter was developed using LTspice in order to analyse the EMI reduction level. Finally, spectrum simulations were carried out. The chaotic PPM was benchmarked to traditional PWM for the boost converter. Simulations show a significant reduction of EMI with a flattened EMI spectrum.
Four-module three-phase permanent-magnet synchronous motor based PWM modulation strategy for suppressing vibration and common mode current

In high-power occasions such as locomotive traction and ship propulsion, parallel inverters are often used to drive multi-phase motors or multi-module motors to increase capacity. Under this background, this paper attempts to improve the transmission quality of the motor system at the switching frequency only by changing the modulation method. The modulation strategy based on the four-module motor proposed in this paper can simultaneously suppress the high-frequency vibration of the motor and the common-mode current To meet this requirement, a motor with 4 modules is used in this modulation scheme. In specific implementation, the proposed scheme uses both carrier phase shift and common mode voltage cancellation strategies. Use the controller to uniformly and synchronously drive the parallel inverters. This article also compares the advantages and disadvantages of different methods under different working conditions.