Miracle-dz/UniFAR-FTUs huggingface dataset:
The Pseudo-Inverse of a Product

Let A and B be bounded linear operators on a complex Hilbert space H, such that the range of each is a closed subspace of H. The following three conditions are necessary and sufficient for the pseudo-inverse of $AB$to be the pseudo-inverse of A followed by the pseudo-inverse of B : (i) the range of $AB$ must be closed; (ii) the range of $A^ * $ must be invariant under $BB^ * $; (iii) the intersection of the range of $A^ * $ and the kernel of $B^ * $ must be invariant under $A^ * A$. We use this basic result to obtain a simple technique for computing the pseudo-inverse of a given operator, particularly a given matrix.
Basic phenomena in low-pressure noble gas discharges: The role of heavy particle induced processes

We have studied in detail the role of heavy particle processes in the gas phase (fast atom-atom and ion-atom collisions) and at the electrode surfaces (impact of fast atoms and ions on the metal surface) in low pressure He and Ar d.c. discharges by means of computer simulation and experiments. Our numerical studies have been based on Monte Carlo and hybrid (Monte Carlo + fluid) simulations. We have quantified the contributions of these processes to the characteristic breakdown behavior (Paschen curve) of He discharges, the complex self-sustainment mechanism of a low pressure, 4000 Volt helium discharge and the characteristic light emission profiles of Ar discharges.
A broadband planar quasi-Yagi antenna

A novel broadband planar antenna based on the classic Yagi-Uda dipole array is presented. This "quasi-Yagi" antenna achieves a measured 48% bandwidth for VSWR <2, better than 12 dB front-to-back ratio, smaller than -15 dB cross polarization, 3-5 dB absolute gain and a nominal efficiency of 93% across the operating bandwidth. Finite-difference time-domain simulation is used for optimization of the antenna and the results agree very well with measurements. Additionally, a gain-enhanced design is presented, where higher gain has been achieved at the cost of reduced bandwidth. These quasi-Yagi antennas are realized on a high dielectric constant substrate and are completely compatible with microstrip circuitry and solid-state devices. The excellent radiation properties of this antenna make it ideal as either a stand-alone antenna with a broad pattern or as an array element. The antenna should find wide applications in wireless communication systems, power combining, phased arrays and active arrays, as well as millimeter-wave imaging arrays.
Microparticles as Plasma Diagnostic Tools

An interesting aspect in the research of complex (dusty) plasmas is the experimental study of the interaction of microparticles with the surrounding plasma for diagnostic purposes. Local electric fields can be determined from the behavior of particles in the plasma, i.e. particles may serve as electrostatic probes. From particle trajectories, also the determination of momentum flux in beams is possible, and the particles serve as force probes. Recently, temperature sensitive features of particular phosphors were utilized for measuring the surface temperature of microparticles confined in the sheath of a rf plasma. The experiments were performed under variation of gas pressure and rf power of the process plasma and offer a promising approach for the improvement of process plasmas and the understanding of plasma‐particle interaction (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evidence for the role of acoustic boundaries in the perception of speech sounds

Evidence from several different experiments in the past has supported the notion that cues for the perception of some of the phonetic features for consonants reside in regions of the speech signal in which there are rapid changes in the spectrum. This paper presents additional data that support this view for two features: The/s‐s/ distinction and the nasal‐stop distinction. In both experiments, continua of synthetic sounds were generated in which certain acoustic properties of the steady‐state portion of the consonant (spectrum of fricative noise or amplitude of nasal murmur) were manipulated and acoustic events in the brief time interval immediately adjacent to the consonantal release were manipulated independently. Listener responses to these stimuli showed that the perception of the relevant phonetic dimension /s‐s/ or nasal stop was influenced strongly by the acoustic properties adjacent to the consonantal release. The acoustic attributes during most of the consonantal closure interval could be manipu.
Selective, high-optrode-count, artifact-free stimulation with infrared light via intrafascicular Utah slanted optrode arrays

Here we present the first use of intraneural and intrafascicular infrared neural stimulation (INS) with early-generation Utah Slanted Optrode Arrays (USOAs) to produce highly selective, artifact-free stimulation of peripheral nerves. USOAs utilize technology previously developed for Utah Slanted Electrode Arrays, and contain 100 silicon optrodes of 0.5 to 1.5 mm length, spaced 400 μm apart in a 10 x 10 grid. The optrodes penetrate into the nerve and closely abut nerve fibers, thus providing multiple, independent, focal sites of stimulation. We first demonstrated that intraneural (but extrafascicular) infrared (IR) stimulation of cat sciatic nerve with conventional optical fibers coupled to a Lockheed Martin Aculight Capella laser produced stronger and more selective neural and muscle compound action potentials (CAPs) than did extraneural INS. We next tested INS through individual USOA optrodes (e.g., wavelength 1873 nm, 5- ms stimulus pulse, < 1 mJ at optrode tip). In contrast to extraneural INS, intrafascicular INS evoked relatively strong and highly selective, optrode-specific responses. Further, there were no observable stimulus artifacts, thereby allowing adjacent electrical recordings. These initial results indicate that intrafascicular INS via USOAs may provide a more efficient, more selective, high-optrode-count means of activating axons, plus greater access to interior nerve fibers.
An Application of the Geostatistical Approach to the Inverse Problem in Two-Dimensional Groundwater Modeling

The geostatistical approach to the estimation of transmissivity from head and transmissivity measurements is developed for two-dimensional steady flow. The field of the logarithm of transmissivity (log-transmissivity) is represented as a zero-order intrinsic random field; its spatial structure is described in this application through a two-term covariance function that is linear in the parameters θ1 and θ2. Linearization of the discretized flow equations allows the construction of the joint covariance matrix of the head and log transmissivity measurements as a linear function of θ1 and θ2. In this particular application the coefficient matrices are calculated numerically in a noniterative fashion. Maximum likelihood estimation is employed to estimate θ1 and θ2 as well as additional parameters from measurements. Linear estimation theory (cokriging) then yields point or block-averaged estimates of transmissivity. The approach is first applied to a test case with favorable results. It is shown that the application of the methodology gives good estimates of transmissivities. It is also shown that when the transmissivities are used in a numerical model they reproduce the head measurements quite well. Results from the application of the methodology to the Jordan aquifer in Iowa are also presented.
The relationship between osteochondral lesion of the talus and the foot arch angles in adults: A retrospective study

Objective: The current study aimed to compare the arch angles of the foot, Achilles tendinopathy, subcutaneous fat tissue thickness of the heel, and epin calcanei (EC) in patients with osteochondral lesion of the talus (OLT). Methods:The magnetic resonance images (MRI) of the ankle performed by the radiology clinic between March 2020 and October 2021 were examined.Based on the MRI findings, the patients diagnosed with OLT were included in the study group (n = 55) and those not diagnosed with OLT formed the control group (n = 118). All the patients included in the study were investigated for their demographic characteristics and presence of EC. Weight-bearing lateral X-ray images were used to measure the lateral talus-first metatarsal angle (Meary’s angle), lateral talocalcaneal angle (LTCA), and calcaneal inclination angle (also known as the calcaneal pitch). Results: The study and control groups had no significant difference in terms of gender distribution (P = 0.575). The patients in the study group had a significantly higher mean age than the control group (P < 0.001). Evaluation of the arch angles of the foot showed the patients with OLT to have higher LTCA and calcaneal pitch angles and greater subcutaneous fat thicknesses (p < 0.001, p < 0.001, and p = 0.004, respectively). In addition, the study group showed higher rates of patients with EC and Achilles tendinopathy (p = 0.076 and p = 0.019, respectively). Conclusion: Our study demonstrated that sex had no effect on OLT incidence, whereas changes in the LTCA and pitch angles elevated the risk of OLT. Furthermore, increased age was found to be associated with a higher risk of OLT formation. We also showed that Achilles tendinopathy and EC were significantly higher in patients with OLT.A considerable number of future studies are needed to establish whether this significant relationship is causal.
One-Step R-Estimation in Linear Models with Stable Errors

Classical estimation techniques for linear models either are inconsistent, or perform rather poorly, under α-stable error densities; most of them are not even rate-optimal. In this paper, we propose an original one-step R-estimation method and investigate its asymptotic performances under stable densities. Contrary to traditional least squares, the proposed R-estimators remain root-n consistent (the optimal rate) under the whole family of stable distributions, irrespective of their asymmetry and tail index. While parametric stable-likelihood estimation, due to the absence of a closed form for stable densities, is quite cumbersome, our method allows us to construct estimators reaching the parametric efficiency bounds associated with any prescribed values (α0,b0) of the tail index α and skewness parameter b, while preserving root-n consistency under any (α,b) as well as under usual light-tailed densities. The method furthermore avoids all forms of multidimensional argmin computation. Simulations confirm its excellent finite-sample performances.
Approximate estimation for systems with quantized data

Estimation of the state of a nonlinear discrete-time system using quantized data is considered. An exact solution for the maximum likelihood estimate is expressed as the solution of a nonlinear two-point boundary-value problem. Approximate recursive solutions for both the maximum likelihood and the conditional-mean estimates are obtained. The results of Monte-Carlo simulations are presented in which the performance of these two algorithms is compared with that of a Kalman filter in which the quantization error is approximated by white noise.
TRAVELLING WAVE SOLUTIONS IN NONLOCAL REACTION–DIFFUSION SYSTEMS WITH DELAYS AND APPLICATIONS

Abstract This paper deals with two-species convolution diffusion-competition models of Lotka–Volterra type with delays which describe more accurate information than the Laplacian diffusion-competition models. We first investigate the existence of travelling wave solutions of a class of nonlocal convolution diffusion systems with weak quasimonotonicity or weak exponential quasimonotonicity by a cross-iteration technique and Schauder’s fixed point theorem. When the results are applied to the convolution diffusion-competition models with delays, we establish the existence of travelling wave solutions as well as asymptotic behaviour.
Synergistic Inhibiting Effect of Phytochemicals in Rheum palmatum on Tyrosinase Based on Metabolomics and Isobologram Analyses

Tyrosinase (TYR) plays a key role in the enzymatic reaction that is responsible for a range of unwanted discoloration effects, such as food browning and skin hyperpigmentation. TYR inhibitors could, therefore, be candidates for skin care products that aim to repair pigmentation problems. In this study, we used a metabolomics approach combined with the isobologram analysis to identify anti-TYR compounds within natural resources, and evaluate their possible synergism with each other. Rheum palmatum was determined to be a model plant for observing the effect, of which seven extracts with diverse phytochemicals were prepared by way of pressurized solvent extraction. Each Rheum palmatum extract (RPE) was profiled using nuclear magnetic resonance spectroscopy and its activity of tyrosinase inhibition was evaluated. According to the orthogonal partial least square analysis used to correlate phytochemicals in RPE with the corresponding activity, the goodness of fit of the model (R2 = 0.838) and its predictive ability (Q2 = 0.711) were high. Gallic acid and catechin were identified as the active compounds most relevant to the anti-TYR effect of RPE. Subsequently, the activity of gallic acid and catechin were evaluated individually, and when combined in various ratios by using isobologram analysis. The results showed that gallic acid and catechin in the molar ratios of 9:5 and 9:1 exhibited a synergistic inhibition on TYR, with a combination index lower than 0.77, suggesting that certain combinations of these compounds may prove effective for use in cosmetic, pharmaceutical, and food industries.
Understanding Continued Use Intention of AI Assistants

ABSTRACT In recent years, smart home assistants have been used by a large number of people due to their simple, hands-free, voice-based operation. To ensure the long-term success and widespread dissemination of a product, it is important to evaluate its continued use. This study is mainly based on uses and gratifications theory to explore the relationship between the initial use of, gratification provided by, and continued use intention of smart home assistants, and to analyze differences in use by different age groups. The results confirm that different types of SHAs use lead to different levels of gratification in different categories. And gratification of different categories of users has a significant positive impact on the continued use intention. In addition, significant differences exist in the impact path of using smart home assistants to alleviate loneliness, among different age groups.
Numerical methods and software

1. Introduction. 2. Computer Arithmetic and Computational Errors. 3. Linear systems of Equations. 4. Interpolation. 5. Numerical Quadrature. 6. Linear Least-Square Data Fitting. 7. Solution of Nonlinear Equations. 8. Ordinary Diernetial Equations. 9. Optimization and Nonlinear Least Squares. 10. Simulation and Random Numbers. 11. Trigonometirc Approximation and the Fast Fourier Transorm. Bibliography.
Thermal instability in a star—gas system

A composite interstellar model consisting of stars and optically thin radiating plasma is considered in order to investigate the thermal instability arising from possible radiation and other heat-loss mechanisms. The stellar dynamics is governed by the Vlasov equation, while the gas is supposed to be a hydromagnetic plasma, described by the MHD equations, with a density- and temperature-dependent heat-loss function. It is shown that while with cold stars the system is in general unstable irrespective of thermal effects of the plasma, with warm stars having a Maxwellian distribution the thermal plasma considerably influences the stability of the composite system. It is also shown that the otherwise stable composite (with warm stars) configuration may become unstable in the presence of a radiating plasma because of coupling between the heat-loss mechanisms and stellar populations.
Optical implementation of the vortex information channel

Recently, composed vortex fields generated by means of a spatial light modulator working in a dynamical regime have been examined as prospective information carriers. In this paper, an advanced optical set-up utilizing vortices for transfer of information is proposed and experimentally verified. Its operation is based on a sophisticated design of phase-only masks enabling information encoding and decoding. In the proposed vortex communication channel, the photolithographically prepared masks are used for generation of a composed vortex field carrying information. Dynamics of information encoding and decoding is achieved by switching of an array of light sources illuminating the phase masks.
Experimental studies of gyrotropy of crystals

a phenomenon that is not yet fully understood theoretically and has been studied only slightly, and which has a number of distinctive properties as being the strongest manifestation of spatial dispersion. The conclusions of the phenomenological macroscopic theory and their agreement with experiment are discussed briefly. The best-suited substances are summarized, and the nature of the propagation of light waves in crystals is described. A microscopic treatment of the problem is presented with a number of examples of the beststudied crystals. The extent of agreement between theory and experiment, the relation of the gyrotropy to the crystal structure and of its constituent elements to the energy levels (electronic, vibronic, and vibrational) and to exciton effects are analyzed. Molecular, ionic, and covalent crystals and semiconductors are discussed; magnetoelectric media and liquid crystals are covered. Studies published up to the beginning of 1974 are used.
Tubing: An Alternative to Clustering for the Classification of Ensemble Forecasts

Abstract Tubing is a method of classification of meteorological forecasts. The method has been designed to facilitate a human interpretation of the distribution of forecasts produced by an ensemble prediction system (EPS). This interpretation aims to complement probabilistic forecasts generated from EPS weather parameter probability distributions. Ensemble forecasts are generally classified according to their similarities. On the other hand, ensemble distributions rarely prove multimodal in practice. The tubing method disregards possible modes and gives instead more emphasis to the central part of the distribution where the ensemble mean is located. Ensemble forecasts are then classified according to the way they differ from the ensemble mean. The tubing algorithm first groups the members lying around the ensemble mean into the central cluster. Remaining ensemble members are classified into a number of tubes. A tube is a cylinder ranging from the central cluster to an extreme member of the distribution. T.
Comparison and Selection of Spike Encoding Algorithms for SNN on FPGA

The information in Spiking Neural Networks (SNNs) is carried by discrete spikes. Therefore, the conversion between the spiking signals and real-value signals has an important impact on the encoding efficiency and performance of SNNs, which is usually completed by spike encoding algorithms. In order to select suitable spike encoding algorithms for different SNNs, this work evaluates four commonly used spike encoding algorithms. The evaluation is based on the FPGA implementation results of the algorithms, including calculation speed, resource consumption, accuracy, and anti-noiseability, so as to better adapt to the neuromorphic implementation of SNN. Two real-world applicaitons are also used to verify the evaluation results. By analyzing and comparing the evaluation results, this work summarizes the characteristics and application range of different algorithms. In general, the sliding window algorithm has relatively low accuracy and is suitable for observing signal trends. Pulsewidth modulated-Based algorithm and step-forward algorithm are suitable for accurate reconstruction of various signals except for square wave signals, while Ben's Spiker algorithm can remedy this. Finally, a scoring method that can be used for spiking coding algorithm selection is proposed, which can help to improve the encoding efficiency of neuromorphic SNNs.
Assistente para Desenvolvimento de Software Crítico segundo a IEC 61508

Uma ferramenta de apoio ao projeto de software facilita o desenvolvimento de software seguro principalmente quando este deve seguir normas rigorosas de segurança crítica como a EC 61508. A norma é extensa e detalhada tornando penosa sua aplicação por desenvolvedores não familiarizados com as áreas de tolerância a falhas e segurança funcional. Apresentamos uma ferramenta de apoio para facilitar a aplicação de cada um dos requisitos de segurança da IEC 61508 levando em consideração o ciclo de vida de software crítico. A ferramenta verifica se todas as atividades foram completadas e mantém a documentação necessária ao processo de certificação de segurança.
Natural Convection in a Square Cavity due to Combined Driving Forces

This paper presents an analytical and numerical study of natural convection in a two-dimensional square cavity filled with a binary gas due to combined temperature and concentration gradients. The transport equations are solved numerically using finite-difference techniques. Excellent comparisons have been obtained with benchmark solutions and other results available in the literature. The analysis indicates that the velocities at the vertical walls are inversely proportional to the concentration parameter Γ. For Γ » 1, the local and average Nusselt and Sherwood numbers at the vertical surfaces are independent of Γ. The analysis also reveals that the Nusselt numbers are strongly dependent on Γ for Γ < 1 as well as on Pr/Sc for N = 1. A sensitivity study indicates that the heat and mass transport across the cavity increases with ∣1 — N∣, where N is the stability number. The direction of circulation undergoes a reversal at N = 1.
Performance assessment of a new dynamic scan mode for perfusion computed tomography using a biological phantom

Perfusion computed tomography is increasingly being used for stroke and tumor assessment. Using continuous periodic table movement the spatial coverage can be increased beyond the detector width with a new adaptive spiral scanning technique (A4DS). The purpose of this study was to compare perfusion values acquired with the A4DS technique with results from standard dynamic scans at different temporal sampling rates. A biological perfusion phantom (preserved porcine kidney) was scanned with both techniques. In standard mode three scans were performed at adjacent overlapping positions (detector width 38.4 mm) covering the whole phantom. Data were reconstructed with temporal resolutions of 0.5, 1 and 1.5 s. The A4DS scan was performed with a cycle time of 1.5 s and scan ranges of 100 and 148 mm respectively. The phantom was not repositioned between scans in order to assure that identical image slices showed identical phantom slices. Tissue flow was calculated with a deconvolution type algorithm. Regions of interest were drawn in strongly and moderately enhancing areas and around the whole cortex in three slices in the upper, central and lower portion of the phantom. In the flow range of 40 to 100 ml/100ml/min values did not differ by more than 5 ml/100ml/min between any of the scan protocols used. The correlation between the continuous table movement modes and the 0.5 s standard mode was excellent (r2>0.98) indicating that the new mode is well suited for perfusion measurements and allows increasing the coverage by almost a factor of four.