Miracle-dz/UniFAR-FTUs huggingface dataset:
Seismic Source Representation for Spall

Spall may be a significant secondary source of seismic waves from underground explosions. The proper representation of spall as a seismic source is important for forward and inverse modeling of explosions for yield estimation and discrimination studies. We present a new derivation of a widely used point force representation for spall, which is based on a horizontal tension crack model. The derivation clarifies the relationship between point force and moment tensor representations of the tension crack. For wavelengths long compared with spall depth, the two representations are equivalent, and the moment tensor time history is proportional to the doubly integrated time history of the point force. Numerical experiments verify that, for regional seismic phases, this equivalence is valid for all frequencies for which the point-source (long wavelength) approximation is valid. Further analysis shows that the moment tensor and point force representations retain their validity for non-planar spall surfaces, provided that the average dip of the surface is small. The equivalency of the two representations implies that a singular inverse problem will result from attempts to infer simultaneously the spectra of both these source terms from seismic waveforms. If the spall moment tensor alone is estimated by inversion of waveform data,more » the inferred numerical values of its components will depend inversely upon the source depth which is assumed in the inversion formalism. « less
Rho GTPase Signaling in Platelet Regulation and Implication for Antiplatelet Therapies

Platelets play a vital role in regulating hemostasis and thrombosis. Rho GTPases are well known as molecular switches that control various cellular functions via a balanced GTP-binding/GTP-hydrolysis cycle and signaling cascade through downstream effectors. In platelets, Rho GTPases function as critical regulators by mediating signal transduction that drives platelet activation and aggregation. Mostly by gene targeting and pharmacological inhibition approaches, Rho GTPase family members RhoA, Rac1, and Cdc42 have been shown to be indispensable in regulating the actin cytoskeleton dynamics in platelets, affecting platelet shape change, spreading, secretion, and aggregation, leading to thrombus formation. Additionally, studies of Rho GTPase function using platelets as a non-transformed model due to their anucleated nature have revealed valuable information on cell signaling principles. This review provides an updated summary of recent advances in Rho GTPase signaling in platelet regulation. We also highlight pharmacological approaches that effectively inhibited platelet activation to explore their possible development into future antiplatelet therapies.
Low Profile Triangle Slot Element Antenna for Array Applications

Single fed array antenna consisting of four triangle cavity backed slot element antennas is introduced in this paper. A radiating rectangular slot is opened on the upper surface of the unit antenna. A thin triangular substrate integrated waveguide (SIW) cavity is adopted. Moreover, grounded coplanar waveguide (GCPW) to excite TE120 modeis used. This element antenna reaches a well simulation gain of 5.8 dBi as well as low cross polarization level can be geted. The proposed unit antenna is designed 1x4 array antennas and use a compact feed network.Measurement results indicate that the array antenna achieves a high gain up to 10.7 dBi, this result reveals that this antenna retains well radiation property compared with conventional array antennas. Moreover, low-profile, convenient layout and compact structure are it's merits.
Breakdown of the dipole blockade with a zero-area phase-jump pulse

We theoretically investigate the effect of a zero-area pulse on the excitations of interacting Rydberg atoms. The unexpected breakdown of dipole blockade occurs in the strong Rydberg blockade regime, which results from the nonadiabatic character of a phase-jump pulse interacting with the atoms. We also check the effect of the modulation on the final probability of double excitations and find that the switching time should be short enough to observe the breakdown of dipole blockade.
Modified Nelder–Mead Method for High-Dimensional Low-Budget Optimization

Black-box optimization (BBO) is a widely used technique for solving a variety of optimization problems including real-world applications with a high-dimensional expensive objective function. Among BBO methods, the Nelder–Mead (NM) method, which is a local search heuristic using a simplex, has been successful due to its simplicity and practical performance on low-dimensional problems. However, the NM method requires $n+1$ and $n$ evaluations to perform its initialization and Shrinkage operations respectively to optimize an n-dimensional objective. This is problematic when the objective is computationally and/or financially expensive because, in such a situation, we usually have a limited evaluation budget but those operations consume most of the entire budget. In this study, to address this drawback, we propose a simple but practical modification of the NM method that efficiently works for high-dimensional low-budget optimization. Our numerical results demonstrate that the proposed approach outperforms the original NM method and the random search baselines on BBO benchmark problems.
Safe Deep Reinforcement Learning-Based Constrained Optimal Control Scheme for HEV Energy Management

Considering physical constraints in online optimization and training safety is a challenge for the implementation of the deep reinforcement learning (DRL) algorithm. Especially for the nonlinear system, the mapping relationship between the output action of the agent and the control signals is difficult to obtain. This article proposes a novel DRL framework for online optimization in energy management of a power-split hybrid electric vehicle (HEV), which combines a neural network (NN)-based multiconstraints optimal strategy and a rule-based-restraints system (RBRS). The proposed method named reward-directed policy optimization (RDPO) adopts the exterior point method (EPM) and curriculum learning (CL) to direct the agent to recognize and avoid irrational control signals and optimize the fuel economy. The energy management strategy (EMS) considering fuel consumption minimization and irrational control signals’ avoidance is optimized by training the agent through the world light vehicle test cycle (WLTC). A competitive fuel economy, 4.495 L/100 km, is achieved with no irrational control signals. Based on the online adaptability evaluation conducted, the fuel consumption of the vehicle under the New European Driving Cycle (NEDC) and the China Typical Urban Driving Cycle (CTUDC) has been reduced to 4.113 L/100 km and 3.221 L/100 km, respectively, with no irrational control signals. The superiority in optimization, calculation efficiency, and safety is verified through comparisons with various DRL agents.
Lagrangian Meshfree Formulation for Analysis of Geotechnical Materials

A Lagrangian reproducing kernel formulation is introduced as an approximation of field variables under the Galerkin meshfree framework of geomechanics. The reproducing kernel approximation is formulated with reference to the material coordinates, yielding an approach that is applicable to both total and updated Lagrangian formulations. In the method presented, geotechnical materials described by pressure-sensitive multisurface plasticity with a cap hardening rule are considered in the meshfree formulation. The solution obtained from the meshfree method with linear basis was compared to that of bilinear finite elements for elastoplastic analysis of geotechnical materials.
Biometric Recognition: A Systematic Review on Electrocardiogram Data Acquisition Methods

In the last decades, researchers have shown the potential of using Electrocardiogram (ECG) as a biometric trait due to its uniqueness and hidden nature. However, despite the great number of approaches found in the literature, no agreement exists on the most appropriate methodology. This paper presents a systematic review of data acquisition methods, aiming to understand the impact of some variables from the data acquisition protocol of an ECG signal in the biometric identification process. We searched for papers on the subject using Scopus, defining several keywords and restrictions, and found a total of 121 papers. Data acquisition hardware and methods vary widely throughout the literature. We reviewed the intrusiveness of acquisitions, the number of leads used, and the duration of acquisitions. Moreover, by analyzing the literature, we can conclude that the preferable solutions include: (1) the use of off-the-person acquisitions as they bring ECG biometrics closer to viable, unconstrained applications; (2) the use of a one-lead setup; and (3) short-term acquisitions as they required fewer numbers of contact points, making the data acquisition of benefit to user acceptance and allow faster acquisitions, resulting in a user-friendly biometric system. Thus, this paper reviews data acquisition methods, summarizes multiple perspectives, and highlights existing challenges and problems. In contrast, most reviews on ECG-based biometrics focus on feature extraction and classification methods.
Singular Perturbation of Autonomous Linear Systems

Let $X_\varepsilon (t) = \exp (({{A + B} /\varepsilon })t)$ where A, B are $n \times n$ matrices. It is shown that $X_\varepsilon (t)$ converges pointwise for $t > 0$ as $\varepsilon \to 0^ + $ if and only if Index $B \leqq 1$ and the nonzero eigenvalues of B have negative real part. An explicit representation of the limit of $X_\varepsilon (t)$ is given. These results are applied to the singularly perturbed system $\dot x = A_1 (\varepsilon )x + A_2 (\varepsilon )y$, $\varepsilon \dot y = B_1 (\varepsilon )x + B_2 (\varepsilon )y$. This paper differs from earlier work both in the derivation of necessary and sufficient conditions and in the explicit forms for the limits.
Multiport Network S-parameter Restoration and Calibration with 2-port Network Analyzer

In this paper, a multiport network S-parameter restoration and calibration procedure is proposed. Taking advantages of the analysis method for multiport network with arbitrary loads in S-parameter domain, the procedure involves no additional standard calibration kit but only a 2-port vector network analyzer (VNA) and a few arbitrary loads. Going through all 2-port combinations for measurement and leaving the remaining ports to be loaded with arbitrary terminations, S-parameters of an N-port device under test (DUT) are reconstructed by no more than N! /(2! (N-2)! ) times of measurement. This procedure does not complicate experiment operation and instead decreases cost of multiport measurement. Results of this procedure is compared with standard $\boldsymbol{50 \ \Omega}$ matching calibration for verification.
Phylogeography as a Proxy for Population Connectivity for Spatial Modeling of Foot-and-Mouth Disease Outbreaks in Vietnam

Bayesian space–time regression models are helpful tools to describe and predict the distribution of infectious disease outbreaks and to delineate high-risk areas for disease control. In these models, structured and unstructured spatial and temporal effects account for various forms of non-independence amongst case counts across spatial units. Structured spatial effects capture correlations in case counts amongst neighboring provinces arising from shared risk factors or population connectivity. For highly mobile populations, spatial adjacency is an imperfect measure of connectivity due to long-distance movement, but we often lack data on host movements. Phylogeographic models inferring routes of viral dissemination across a region could serve as a proxy for patterns of population connectivity. The objective of this study was to investigate whether the effects of population connectivity in space–time regressions of case counts were better captured by spatial adjacency or by inferences from phylogeographic analyses. To compare these two approaches, we used foot-and-mouth disease virus (FMDV) outbreak data from across Vietnam as an example. We identified that accounting for virus movement through phylogeographic analysis serves as a better proxy for population connectivity than spatial adjacency in spatial–temporal risk models. This approach may contribute to design surveillance activities in countries lacking movement data.
Measurement of Spatial Coherence Using Speckle Patterns

A method is described for measuring the spatial coherence of light by means of speckle patterns produced by using ground glass as a random inhomogeneous medium. The theory of the method is developed and its verification is performed experimentally by using a laser and a mercury lamp as light sources. Characteristics of the present method for exploring the spatial coherence of light fields are discussed.
A Bessel Beam Holographic Reflectarray Antenna for Wireless Power Transmission at 5.8GHz

A 5.8GHz reflectarray antenna which can generate non-diffraction Bessel beams and realize beam direction control in near-field based on the holography method is presented in this paper. It is design for wireless power transmission, the sub-wavelength unit cell of the reflectarray antenna with high reflection coefficient can obtain an accurate phase distribution to improve the energy transmission efficiency. The metasurface of the reflectarray antenna is composed of 43×43 unit cells can realize 10m non-diffraction range by simulation, the radiated power attenuation is less than 2dB. In addition, the Bessel beams deflection of 10° from +z direction is achieved, the radiated power attenuation is less than 4dB. The design can use in the long-distance wireless power transmission for its long non-diffraction range and accurate beam control.
Analysis of voice perturbations using an asymmetric model of the vocal folds

A mathematical model was developed to investigate possible causes of jitter and shimmer. The model builds on the classic, lumped element model of Ishizaka and Flanagan and allows for asymmetric motions of the vocal folds and aerodynamic imbalances. The intraglottal pressures were derived from empirical pressure data obtained from a static physical model of the larynx (M5). The mathematical model is based on ten, second‐order, nonlinear, coupled, ordinary differential equations that were solved simultaneously using the software Mathematica. The solutions were analyzed graphically and numerically to identify perturbations in the fundamental frequency and amplitude of the glottal airflow. Jitter and shimmer were quantified using the jitter factor and the amplitude variability index. The results indicate that only time‐dependent variations in biomechanical and aerodynamic parameters result in jitter and shimmer. The magnitudes of jitter and shimmer tend to be less than those observed in the natural sounding voice, even when the asymmetries are large. Although time‐independent asymmetries may cause the vocal folds to oscillate out of phase or with different amplitudes, they tend to entrain and vibrate at a common frequency. [Work supported by NIH R01DC03577. ]
An Electronic Publication Dedicated to Early Stellar Evolution and Molecular Clouds Abstracts of Recently Accepted Papers Vortices in Circumstellar Disks Magnetic Braking, Ambipolar Diffusion, and the Formation of Cloud Cores and Proto- Stars: Ii. a Parameter Study

We discuss the physics of vortices in the circumstellar disks associated with young stellar objects. We elucidate the basic physical properties of these localized storm systems. In particular, we consider point vortices, linear vortices, the effects of self-gravity, magnetic fields, and nonlinear aspects of the problem. We find that these vortices can exist in many different forms in the disks of young stellar objects and may play a role in the formation of binary companions and/or giant planets. Vortices may enhance giant planet formation via gravitational instability by allowing dust grains (heavy elements) to settle to the center on a short time scale; the gravitational instability itself is also enhanced because the vortices also create a larger local surface density in the disk. In addition, vortices can enhance energy dissipation in disks and thereby affect disk accretion. Finally, we consider the possibility that vortices of this type exist in molecular clouds and in the disk of the galaxy itself. On all of these size scales, vortices can produce long-lived structures which may correspond to observed structures in these systems. The formulation of the problem of the formation of protostellar cores in self-gravitating, magnetically supported, rotating, isothermal model molecular clouds was presented in a previous paper, where detailed numerical simulations for two different model clouds were also discussed. In this paper, we study the effect of varying five dimensionless free parameters: the ratio ρ of external density and central density in a reference state (which is related simply to an initial equilibrium state), the initial radial length scale l ref of the column density of the cloud, the central angular velocity of the reference state Ω c,ref , the central neutral-ion collision time in the reference state τ ni,ref (which is inversely proportional to the collapse retardation factor ν ff ≡ τ ff /τ ni), and the exponent k in the relation between the ion and neutral densities n i ∝ n k n. In addition to the models previously presented, seven more models are investigated here. Different values (1/1000 − 1/100) of the initial magnetic-braking efficiency parameter ρ(> 0) do not significantly affect the evolution; magnetic braking remains effective during the quasistatic phase, and ineffective during the (dynamic) collapse of the magnetically and thermally supercritical core. The initially very effective magnetic braking also means that the solution is insensitive to values of Ω c,ref. Different values of l ref yield …
Efficient discrete cosine transform and quantization algorithm based on eliminating redundant computations in H.264 video encoding

We propose a new efficient discrete cosine transform (DCT) and quantization algorithm for the H.264 encoder. We theoretically analyze integer DCT and quantization of the H.264 encoder. A theoretical analysis shows that there are redundant calculations for DCT and quantization. In the proposed algorithm, one of four methods—1. DCT skip; 2. reduced DCT1; 3. reduced DCT2; 4. original DCT—is selected by using the minimum SAD information obtained in the motion estimation. The reduced DCT1 and reduced DCT2 eliminate the redundant calculations required for DCT and quantization. The simulation results show that the proposed algorithm achieves an approximately 15 to 25% computational saving without video-quality degradation, compared to the conventional method.
Reconfigurable Liquid Frequency Selective Rasorber Design and Its Application in Antenna System

Liquid FSRs will overcome several disadvantages of electrically controlled reconfigurable FSRs and offer an important complement to traditional FSRs by fully using the fluidity, high dielectric constant, and dispersion properties of liquids. This paper provides a review and discussion of liquids for recent research in our group. First, the electromagnetic properties of liquid material for FSR designs are analyzed. Then, recent designs for reconfigurable, extra wideband FSR, and low RCS antennas are thoroughly examined. Finally, the difficulties in producing liquid FSR for real-world applications are highlighted and explained.
A Wideband Dual-Circularly-Polarized Magneto-Electric Dipole Array at K-Band

In this paper, a wideband dual-circularly-polarized (dual-CP) antenna array which consists of dual-CP magneto-electric dipole (ME-dipole) elements at $K$-band is designed. The dual-CP ME-dipole contains two input ports for exciting LHCP and RHCP radiated waves separately. The use of two sequential rotation (SR) feeding networks significantly improves the impedance match and the purity of circular polarization (CP) of the ME-dipole array. The resulting array's overall working frequency band is 18 GHz-24 GHz. Within this band, the reflection coefficients of two ports are below −10 dB, the port isolation is better than 10 dB, the side lobe level (SLL) of the radiation pattern is below −10 dB, and axial ratio (AR) is below 3 dB. Meanwhile, the main beams of RHCP wave and LHCP wave have maximum gain values of 16.2 dBi and 15.1 dBi, respectively, while the gain fluctuations are less than 3 dB within the operational band. The antenna array designed in this paper can be well applied in various kinds of communication systems, for example, radar systems and satellite communications.
Autonomous Landing Guidance and Control for Cooperative UAV-USV Systems

This paper investigates the autonomous landing guidance and control for cooperative unmanned aerial vehicle-unmanned surface vehicle (UAV-USV) systems. A deep learning-based visual positioning architecture is developed to estimate the position of the landing pad on the USV from images captured by the UAV’s onboard camera. By introducing the spatial softmax operation into the conventional convolutional networks, the positioning accuracy and the computational efficiency are improved. Then, a three-stage landing guidance strategy with safety protocols is proposed, and a reinforcement learning-based velocity controller from our earlier work is employed for the UAV motion control. Finally, the proposed approaches are validated in our built simulation platform with challenging landing tasks. The results show that the UAV can safely land on a moving USV under the disturbances of sea waves and wind gusts.
Transparency Versus Populism

This article theorizes and analyzes the relationship between populist leaders and government transparency. Employing a paired comparison of leaders in Brazil and the United States before and during the pandemic, it illuminates three interlocking tactics: (a) the weakening of transparency institutions, (b) erasure and suppression of transparency, and (c) corruption of transparency via misuse and misinformation. Populist efforts to subvert pandemic transparency elicited a striking response in both countries: the emergence of “compensatory transparency initiatives” (CTIs). By collating and disclosing subnational pandemic data to fill transparency gaps at the federal level, CTIs drew attention to populist failings.
Recovery of Cu-Fe Alloy from Copper Smelting Slag

Copper smelting slag usually contains 1–6 wt% copper, which can be recovered by pyrometallurgical and flotation processes. However, the tailing slags still consist of 0.3–0.7 wt% Cu and 35–45 wt% Fe equivalents to those in the copper and iron ores, respectively. Most of the research was focused on the recovery of iron from the tailing slags. Copper can increase the mechanical strength, corrosion resistance and antibacterial property of some steels. A new process to recover copper and iron directly and fully from hot copper smelting slag is proposed to produce Cu-Fe alloy for steel production. Effects of flux, temperature, reaction time, reductant type and addition on the recovery of copper and iron were investigated by high-temperature experiments and thermodynamic calculations. It was found that, with 5% CaO and 13–16% carbon additions, most of the copper and iron can be recovered from copper smelting slag at 1350–1400 °C. The copper and iron contents of the reduced slag are lower than 0.1% and 0.5%, respectively, at optimum condition. The new process has the advantages of low energy consumption, low flux addition and high recovery of copper and iron.