Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of Neural Spike Signal Transmission Characteristics in 3-D Heterogeneous Integration

With the continuous development of artificial intelligence, spiking neuromorphic chip is favored for its architectural advantages of memory computing integration. The neural spike signal is used as the transmission signal in the spiking neuromorphic chip, and its completely different characteristics from the digital pulse signal will inevitably lead to different signal integrity problems. In this paper, we model the common Through Silicon Via (TSV) and the interconnection structure model of redistribution layers (RDL) in 3-D heterogeneous integration, analyze the insertion loss and transient impedance of the two structures respectively, and finally perform time-domain transient simulations with neural spike signals of different rising edges in the two models to observe their transmission characteristics. The simulation results show that neural spike signals with shorter rising edges can generate more serious signal integrity problems such as loss, reflection, and delay in the RDL-TSV interconnection structure.
Design of Coaxially-Fed, Concentrically-Cascaded, Cylindrical Metasurfaces

In this paper, arbitrary cylindrical field synthesis is demonstrated using coaxially-fed, concentrically-cascaded meta-surfaces. The metasurfaces are designed using multimodal network theory. The interaction between the feed and the metasurfaces is accounted for by cascading their respective S-matrices. By incorporating the coaxial feed into the design approach, the proposed framework resolves a long-standing difficulty in physically implementing cylindrical metasurface structures.
High-Gain Wire-Patch Based Pattern Reconfigurable Antenna for IoT Applications

A Wire Patch Antenna (WPA) based Electronically Steerable Parasitic Array Radiators (ESPAR) System is proposed for an endfire pattern reconfiguration. The proposed system is characterized by 6 reconfigurable directive beams that combined can cover all 360°over the azimuth plane. Its low profile, high-gain (7.22 dBi) and low side lobe level (-6.3 dB) makes this antenna system suitable for long-range portable devices in IoT environments.
Planar, Lossless and Scan Angle Enhancing Lens for E-band Automotive Radars using Ray Transfer Compensation

A new method to realize a planar lossless scan angle enhancing metasurface lens (SAEML) for automotive application is discussed and proposed. The method uses ray transfer matrix and ray-tracing analysis to extend the scan range and minimize the scan loss. A lens-prototype designed using the proposed method is designed at 76.5 GHz, fabricated, and measured. The prototype features an extended scan range of 54° with a maximum gain loss of 1.4 dB, highlighting this to be the first-reported planar, lossless lens at millimeter-wave spectrum.
A Wideband Balanced-to-Unbalanced Power Divider Based On Coupled Lines

This paper proposes a novel wideband balanced-to-unbalanced (BTU) power divider with phase inverter. Two cascaded T-shaped sections are applied in the design to realize the phase inverter, which reduces the electrical length of transmission lines (TLS). The traditional even/odd-mode analysis methods are employed to obtain the closed-form analytical equations. This circuit shows good performance in differential-mode (DM) respond, common-mode (CM) suppression and isolation. To verify the correctness of the proposed concept, a practical power divider with 4-dB differential-mode bandwidth fractional of 61.8% is designed.
Inverter-Angle-Induced Optimized Frequency Regulation Approach for AC–DC Microgrids Using Consensus-Based Identification

This article proposes a novel approach for mitigating grid frequency deviation during disturbances, utilizing the inverter angles for inverter-based resources connected with multiple dc microgrids. The proposed approach generates dynamic multiple-input–multiple-output system models of dc microgrids interfaced with inverters based on the alternating direction method of multipliers. These frequency-domain-based models generate input–output transfer functions relating to dispatchable distributed energy resource (DER) set points. These are then used as control inputs and grid frequency/individual point of common coupling (PCC) angles (<inline-formula><tex-math notation="LaTeX">$\delta$</tex-math></inline-formula>) for ac–dc multi-microgrid structures depending on their locations in the distribution network. A sensitivity relationship of powers with respect to change in global distribution frequency or individual angle <inline-formula><tex-math notation="LaTeX">$\delta$</tex-math></inline-formula> for each section of ac–dc multi-microgrid is then used to optimally control the DER dynamics such as the frequency deviations are minimal. This approach is tested on commonly seen fault/dynamics and it was observed that the proposed architecture outperforms the state-of-the-art by more than 20% in mitigating frequency deviations.
Research on the simulation technology of distribution automation system based on open communication

With the leap forward development of modern communication and automation control technology, the theoretical connotation and application boundary of distribution automation technology are expanding, providing a platform for integrated regulation and real-time control of distribution big data and complex primary and secondary devices. Based on lEC 61850 standard, this paper introduces the concept of the standard and its typical application in distribution automation system in detail, and also studies the construction method of the main station and terminal simulation system of distribution automation supporting open communication. A hierarchical distributed architecture and object-oriented modeling technology are adopted to complete the semantic cutting of distribution devices and self-description of data objects, to realize accurate identification of devices, real-time communication and fast fault handling, and to provide an effective way to realize interoperability and seamless system integration of intelligent electronic devices from different manufacturers. At the same time, the panoramic display of power distribution automation is realized based on the unified interactive interface, which has strong display and training significance.
Efficient Higher Order VIE Method with Taylor Series Expansion for Wideband Frequency EM Scattering Analysis of Dielectric Objects

In this paper, an efficient volume integral equation (VIE) method with Taylor series expansion (TSE) and higher order hierarchical vector (HOHV) basis functions is developed for fast electromagnetic scattering analysis over a wideband frequency of dielectric objects. In this VIE, the impedance matrix elements can be divided into the frequency dependent item (FDT) and geometric structure dependent term (GSDT), where only GSDT is required to be calculated and stored in advance. Then, during frequency sweeping process, the impedance matrix can be generated by combining the precomputed matrices GSDT and FDT. Besides, due to the hierarchy of the HOHV bases, only one coarse mesh corresponding to the lowest frequency of the given frequency band is generated, and the pre-computed matrices corresponding to the highest order basis are need to be computed. Based on those, the EM scattering corresponding into high frequency point can be calculated simply by adjusting the order of the HOHV bases. This saves much work in geometrical modeling and further improves computational efficiency. In contrast to the conventional scheme for fast EM scattering analysis over a wideband frequency, this HO-TSE-VIE method requires much less computational time while the accuracy remains at the same level. Numerical results are provided to demonstrate its accuracy and efficiency.
Novel coaxial transition for shaped coaxial horn antennas operating at millimeter wave frequencies

This work presents a novel optimized design and analysis of a coaxial coupling structure for standard and shaped horn antennas operating at millimeter wave frequencies. A novel dielectric support structure for the inner conductor and a transition to a 2.92 mm K connector are proposed. The horn’s performance was evaluated through full-wave electromagnetic finite element method analysis performed on Ansys EM. The dimensions of the dielectric structure and transition were optimized using a multi-objective Genetic Algorithm to enhance the horn’s performance. The final design presented a frequency bandwidth greater than 45% (25–40 GHz) with a return loss exceeding 20 dB.
Analyzing ALT Data with Time-varying Stress Profile

We are interested in analyzing the accelerated life testing data obtained under time-varying stresses. This is a generalization of step-stress accelerated life test, where the stress levels are kept constant at each step. Our study shows that the time-dependent proportional hazard model, commonly appeared in the survival data analysis literature, is not applicable for ALTs, because this approach does not take accounts of the cumulative damage that the stress profile exerts on test units. Instead, we assume that products possess constant failure rates over small time intervals, and the change of failure rate by the stress variable still have the proportional hazard property. With these assumptions, it is possible to formulate the data according to a generalized linear model and statistical inferences on model parameters can be carried out. We demonstrate our models and inference procedures by using both synthetic and real datasets.
An Energy Storage Scheduling Strategy Based on Computational Optimization Starting Point

With a large number of new energy sources connected to the grid, the inverse peak characteristics of their power generation have brought great difficulties to the grid scheduling. In recent years, energy storage technology has gradually developed and matured, and its dual characteristics of charge and discharge provide a new solution to the problem of new energy consumption. However, the current peak load shifting scheduling problem for energy storage is mainly solved by intelligent optimization algorithm, which has the disadvantage of low solving efficiency and the risk of falling into a local optimal solution. Therefore, this paper proposes a novel scheduling strategy based on computational optimization starting point for energy storage, which can provide an appropriate iterative starting point for intelligent optimization algorithm through the preset process. Compared with the randomly generated starting point, the calculated starting point can make the objective function tend to the extreme value more quickly and stably. Finally, in the case studies part, a system with solar power generation was taken as the example. The energy storage peak load shifting optimization problem was solved by adopting the calculated starting point and the random generated starting point respectively, and the effectiveness of the proposed strategy is proved by comparing the test results.
Comprehensive Investigation on the Influence of Magnetic Materials on the Weight and Performance of Onboard WPT Systems

In an inductive power transfer (IPT) system, the magnetic core is usually used to improve the coefficient between the primary and secondary coils. However, considering the iron losses on magnetic materials, the addition of magnetic core may affect the system efficiency and, at the same time, increase the weight of the IPT system significantly. Therefore, in this study, the aggregate influence of thickness, permeability, and iron losses of magnetic core on IPT system performance is comprehensively investigated. First, the equivalent circuit model of IPT system is established, and the formulas for different types of losses are analyzed. Then, the three-dimensional models of the IPT system with magnetic core in different shapes are established to simulate the aggregate influence of core thickness, permeability, and iron losses. The simulation results reveal that reducing the core thickness requires a larger saturation flux density of magnetic materials. In addition, only if the material losses below a certain value and an appropriate core shape are adopted, the addition of magnetic material can improve the system efficiency. Finally, experimental validation on a 3-kW IPT system is performed under the conditions of no magnetic core, using ferrite core in radial pattern and hollow square shapes, and using nanocrystalline core with the thickness of 22 μm and 16 μm in radial pattern and hollow square shapes, respectively. The results show that the high efficiency and lower overall weight of the IPT system can be achieved when nanocrystalline core with suitable permeability and shape is used.
Examination of Resonant Cavity Enhanced Strain Compensated SiGeSn/GeSn Interband MQWIP

In this work, mathematical investigation is done for the potential of Group IV alloy based resonant cavity enhanced interband multiple quantum well photodetector (MQWIP). Strain balanced multiple quantum well structure is proposed to be configured between two Bragg reflectors(mirrors) to form a resonant cavity. Responsivity is calculated by solving the rate equation in each GeSn active well region of MQWIP considering interwell carrier transport mechanism and resonant cavity. The result reveals that peak responsivity is significantly higher than that of the MQWIP without resonant cavity at 3.8$\mu$m.
Low Frequency Oscillation Mode Identification Algorithm Based on VMD Noise Reduction and Stochastic Subspace Method

Low-frequency oscillation (LFO) is a security and stability issue that the power system focuses on, measurement data play an important role in online monitoring and analysis of low-frequency oscillation parameters. Aiming at the problem that the measurement data containing noise affects the accuracy of modal parameter identification, a VMD-SSI modal identification algorithm is proposed, which uses the variational modal decomposition algorithm (VMD) for noise reduction combined with the stochastic subspace algorithm for identification. The VMD algorithm decomposes and reconstructs the initial signal with certain noise, and filters out the noise signal. Then, the optimized signal is input into stochastic subspace identification algorithm(SSI), the modal parameters is obtained. Simulation of a three-machine ninenode system verifies that the VMD-SSI mode identification algorithm has good anti-noise performance.
A Reconfigurable Deployable Quadrifilar Helix Antenna for Areas with Diminished Infrastructure

A multi-stable fiber reinforced polymer composite helical latticed-based antenna is presented in this paper. The antenna is designed with a reconfigurable deployable Quadrifilar helix topology that exhibits two different stability states. The first state has a linear polarization with an omnidirectional radiation pattern for terrestrial point to point communication. The second state presents a circular polarization with broadside propagation to ensure satellite-ground communication. The antenna was fabricated and tested where measurement results agree notably with simulated designs. The antenna exhibits extremely light weight and great agility making it suitable for portable deployment for areas with diminished infrastructure.
Design of a Dual Circular-Polarized Shaped-Beam Reflectarray Antenna Using SVR

This work presents the design of a shaped-beam reflectarray working in dual circular polarization (CP) with an isoflux pattern for global Earth coverage. The dual-CP capabilities are achieved using a unit cell based on a linear polarization (LP) Jerusalem cross plus an integrated LP-to-CP polarizer. Surrogate models based on support vector regression of the unit cell for several angles of incidence are trained and used in a direct layout optimization to obtain the design of the reflectarray that produces the desired shaped beam.
Analysis of Partially Reflective Surface Antenna with Different Reflection Magnitudes Using Ray-tracing

It has been shown that a partially reflective surface (PRS) antenna with a larger reflection magnitude has a higher antenna gain, based on practical design examples. In this paper, PRS antennas with different reflection magnitudes are analyzed using an intuitive ray-tracing model. It is derived that the larger reflection magnitude enables a smaller phase delay and a more uniform magnitude distribution across the PRS, which leads to a superior gain. The antennas with different reflection magnitudes were simulated in a full-wave solver to verify the derivation. The simulated phase and magnitude distributions of the PRS antennas agree with the predicted trends from ray-tracing.
Overview of Steady-state Modeling and Optimal Operation of Power System with FACTS

With the development of power grid and renewable energy, power flow over-limit has become an increasingly serious problem which threats security and stability of the system. Flexible alternating current transmission systems (FACTS) provide flexible adjustment of the network structure and parameters, which improve transmitted power of lines and enhance stable operation of the system. It is important to utilize the maximum ability of FACTS devices and achieve optimal operation of the power system. Typical and the most powerful FACTS devices, unified power flow controller (UPFC), interline power flow controller (IPFC) and hybrid power flow controller (HPFC), are firstly introduced, topologies and characteristics are also summarized. Secondly, different equivalent models of FACTS are introduced, and their characteristics are discussed. Finally, models and solution methods for optimal operation of the system with FACTS are introduced, then the direction for further research is prospected.
Compact Two-Stage Origami Horn Antenna for Terahertz CubeSat Networks

With the rapid proliferation of high-speed satellite communication networks enabled by dense constellations in space, CubeSats are expected to be more compact than ever while maintaining large bandwidth operation. A candidate enabler for high-data-rate CubeSat constellations is the terahertz (THz) band (0.1-10 THz), which supports both compactness and large bandwidth. These two come at the cost of high propagation losses and impose the use of very high gain directional antennas, which on their turn drastically impact otherwise simple tasks such as neighbor discovery and broadcasting with nearby satellites. To simultaneously alleviate the challenges of neighbor discovery while overcoming the high path losses in long links, a THz origami horn antenna utilizing commercially-available WR4 waveguide is presented. The proposed antenna has two stages supporting phases of neighbor discovery and high-data-rate communication. The two stages demonstrate gains of 15.7 dBi and 30.7 dBi, respectively, at 218 GHz. The horn antenna is explored as a solution for enabling CubeSat swarms at terahertz frequencies.
Estimation Technique of RCS using LSTM

RCS measurement is a factor that helps design communication systems, antenna systems, and aircraft where scattering and reflection of electromagnetic waves are important. However, RCS measurements of time and cost are particularly related to large items such as aircraft and ships. Accordingly, this study provided a long-short-term memory (LSTM) strategy to solve the above difficulty and increase RCS measurement efficiency. RCS was evaluated using computer simulation, and after learning based on the observed data, RCS prediction data not measured within tolerance was calculated. The estimated data used RMSE to determine the error, and the estimated value indicates the result along the trend line of the observed value.
Learning Strategies for Imperfect Information Board Games Using Depth-Limited Counterfactual Regret Minimization and Belief State

Counterfactual Regret Minimization (CFR) variants have mastered many Poker games by effectively handling a large number of opportunities in private information within relatively short playing histories of the game. However, for imperfect information board games with infrequent chance events but long histories or even loops, the effectiveness of CFR is often limited in practice as the computational complexity grows exponentially with the game length. In this paper, we propose Belief States with Approximation by Dirichlet Distributions and Depth-limited External Sampling for Board Games that enables an effective abstraction even with existence of loops. Experiments show that our proposed methods have the ability to learn reasonable strategies.
Asymmetric ϵ-Support Vectors Regression for Remaining Useful Life Distribution Estimation

Estimating the remaining useful life (RUL) of industrial components is essential in predictive maintenance practice. In real-world applications, both aleatoric uncertainties (e.g., randomness due to uncontrollable factors) and epistemic uncertainties (e.g., ignorance about the model correctness) exist. Therefore, uncertainty quantification is expected to be associated with the point estimation, i.e., an estimation of the RUL probability density function (PDF) is necessary. However, existing data-driven methods which can give a probabilistic estimation of RUL have limitations when applying to real-world industrial systems: statistical methods often rely on certain assumptions on the degradation process; probabilistic machine learning methods usually have large complexity and need some prior knowledge on the parameter distribution and/or likelihood model.
Load frequency control of isolated microgrid based on soft actor-critic algorithm

Load variation and uncertainty of power output from distributed power sources such as wind power in microgrids have caused great difficulties for the stability of the whole microgrid. To address this problem, this paper uses deep reinforcement learning algorithm to design a controller to control the frequency of the isolated microgrid: firstly, a Load Frequency Control (LFC) model of the isolated microgrid was built containing wind power, energy storage, micro gas turbine, load and corresponding power increment constraints, secondly, Next, the LFC controller is designed using the flexible action evaluation algorithm, and the microgrid controller is generated through multiple learning training based on the reward function Finally, The SAC controller proposed in this paper can provide better frequency power quality for islanded microgrids when load step disturbances and load random disturbances occur in the system.
Bounds on Substructure Dielectric Resonator Antennas Using Characteristic Modes

This paper presents a recent development on the fundamental limits of substructure dielectric resonator antennas (DRAs). Specifically, the substructure DRAs are found to have higher resonance frequencies than the superstructure DRA, and a bounding relation on Q factor is also obtained. Numerical examples based on a ring DRA and a cylindrical DRA is examined here to demonstrate the bounding relations.