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Parity-time (PT) symmetry has enabled the demonstration of fascinating wave phenomena in non-Hermitian systems characterized by precisely balanced gain and loss. Until now, the exploration and observation of PT symmetry in scattering settings have largely been limited to propagating waves. Here, we demonstrate a versatile coupled-resonator acoustic waveguide (CRAW) system that enables the observation of PT-symmetric scattering responses for evanescent waves within a bandgap. By examining the generalized scattering matrix in the evanescent wave regime, we observe hallmark PT-symmetric phenomena—including phase transitions at an exceptional point, anisotropic transmission resonances, and laser-absorber modes—in systems that do not require balanced distributions of gain and loss. Owing to the peculiar energy transfer features of evanescent waves, our results not only demonstrate a distinct pathway for observing PT symmetry, but also enable strategies for exotic energy tunneling mechanisms, paving fresh directions for wave engineering grounded in non-Hermitian physics. Non-Hermitian physics and parity-time (PT) symmetry are of broad interest in classical wave systems. This work demonstrates evanescent wave manipulation and scattering control based on PT symmetry in a versatile coupled-resonator acoustic waveguide (CRAW) system, which not only extends the framework of non-Hermitian physics but also offers strategies for near-field manipulation and control. [ABSTRACT FROM AUTHOR]

Linear discriminant analysis (LDA) is a well-known supervised method that can perform dimensionality reduction and feature extraction effectively. However, traditional LDA-based methods need to be turned into the trace ratio form to compute the closed-form solution, in which the within-class scatter matrix should be nonsingular. In this article, we design a new model named generalized robust linear discriminant analysis (GRLDA) method to tackle this disadvantage and improve the robustness. GRLDA uses L 2 , 1 -norm on both loss functions to reduce the influence of outliers and on regularization term to obtain joint sparsity simultaneously. The intrinsic graph and the penalty graph are constructed to characterize the intraclass similarity and interclass separability, respectively. A novel optimization method is proposed to solve the proposed model, in which a quadratic problem on the Stiefel manifold is involved to avoid the inverse computation on a singular matrix. We also analyze the computational complexity rigorously. Finally, the experimental results on face, object, and medical images exhibit the superiority of GRLDA. [ABSTRACT FROM AUTHOR]

String theory on AdS3 × S3 × T4 geometries supported by a combination of NS-NS and R-R charges is believed to be integrable. We elucidate the kinematics and analytic structure of worldsheet excitations in mixed charge and pure NS-NS backgrounds, when expressed in momentum, Zhukovsky variables and the rapidity u which appears in the quantum spectral curve. We discuss the relations between fundamental and bound state excitations and the role of fusion in constraining and determining the S matrices of these theories. We propose a scalar dressing factor consistent with a novel u-plane periodicity and comment on its close relation to the XXZ model at roots of unity. We solve the odd part of crossing and show that our solution is consistent with fusion and reduces in the relativistic limit to dressing phases previously found in the literature. [ABSTRACT FROM AUTHOR]

Density fluctuation potential induced by a screening of the photohole scatters the photoelectron and generally causes its emission delay from the scattering matrix in the photoemission spectroscopy, where the photoemission delay usually quantifies the extrinsic loss of the photoelectron depending on the atomic orbital. Without the potential scattering, however, the photoemission from the coherent two-state mixture created by the laser driving is found to undergo the unexpected photoemission delay, which originates from the mixed photoemission matrix. Using the Haldane model, we analytically calculate such coherent mixing induced photoemission delay in an angle-resolved mode, which is found to reveal the local Berry curvature structure as long as the coherent mixing is sustained. This finding is confirmed through the streaking computation for the photoemission delay by solving the time-dependent Schrödinger equation and suggests that the photoemission delay be a new spectroscopic diagnosis of the material topology of two-dimensional semiconductors. [ABSTRACT FROM AUTHOR]

The main goal of the SPASCHARM experiment is the systematic study of spin phenomena at intermediate energies. For this purpose, it is planned to create a beam of polarized protons and antiprotons. The research includes, among other things, the study of elastic scattering. Some of the required equipment for polarimetry is planned to be also used to study elastic scattering immediately after the creation of such a channel. In this work, a set of observables necessary for model-free reconstruction of elastic proton–proton scattering amplitudes is investigated and determined. [ABSTRACT FROM AUTHOR]

In recent years, much attention has been paid to integrated photonics devices based on nonlinear media. A generalization of the transfer matrix method to problems in plane-parallel layered media with quadratic and cubic nonlinearity is proposed. The incident radiation can be either a monochromatic wave or a non-monochromatic pulse. Previously, such problems could only be solved using grid methods. The proposed approaches significantly expand the range of applicability of matrix methods and are drastically superior in efficiency to the well-known grid methods. [ABSTRACT FROM AUTHOR]

The estimation of signal dimension under heavy-tailed latent variable models is studied. As a primary contribution, robust extensions of an earlier estimator based on Gaussian Stein's unbiased risk estimation are proposed. These novel extensions are based on the framework of elliptical distributions and robust scatter matrices. Extensive simulation studies are conducted in order to compare the novel methods with several well-known competitors in both estimation accuracy and computational speed. The novel methods are applied to a financial asset return data set. [ABSTRACT FROM AUTHOR]

A Landau–Zener-type formula for a degenerate avoided-crossing is studied in the non-coupled regime. More precisely, a 2 × 2 system of first-order h-differential operator with O (ε) off-diagonal part is considered in 1D. Asymptotic behavior as ε h m / (m + 1) → 0 + of the local scattering matrix near an avoided-crossing is given, where m stands for the contact order of two curves of the characteristic set. A generalization including the cases with vanishing off-diagonals and non-Hermitian symbols is also given. [ABSTRACT FROM AUTHOR]

Clarifying China's position in the global system is an important logical basis for developing national diplomacy. Although much research has been done on China's development status, most studies have been based on country comparisons or institutional environment. In today's networked era in which the global economy, trade, personnel, and information are closely connected, studies on China's global position and its status changes and influencing factors in multiple contact networks are still insufficient. In this study, from the perspective of diverse global contact networks, we constructed economic, cultural, and political influence indices to explore the changes and influencing factors on China's status in the global system from 2005 to 2018. The results show that during the study period, China's global influence in the fields of economic ties, cultural exchanges, and political contacts increased significantly, but its influence in the fields of cultural exchanges and political contacts lagged far economic ties. The pattern of China's economic influence on various economies around the world has shown a transformation from an 'upright pyramid' to an 'inverted pyramid' structure. The proportion of these economies in low-influence zones has decreased from more than 60% in 2005 to less than 20% in 2018. China's cultural and political influence on various economies around the world has increased significantly; however, for the former, the percentage of high-influence areas is still less than 20%, whereas for the latter the percentage of these economies in medium- and high-influence areas is still less than 50%. Analyses such as a scatter plot matrix show that geographical proximity, economic globalization, close cooperation with developing countries, and a proactive and peaceful foreign policy are important factors in improving China's status in the diverse global network system. [ABSTRACT FROM AUTHOR]

Most domain adaptive methods enhance the classification performance of target domain via overcoming the distribution difference between source and target domains while ignoring the nature of classifier, i.e., the data being correctly classified by classifier is due to the high separability of data. Therefore, inspired by this, we propose a simple yet effective domain adaptive method in accordance with the property of classifier, namely cross-domain Fisher discrimination criterion (CFDC). CDFC is intended to upgrade the inter-class discrimination and intra-class compactness of samples for the scenario where the target domain has few labeled samples. Specifically, we reconstruct the intra- and inter- class scatter matrices of Fisher's criterion from a geometrically intuitive perspective, enabling it to extract highly discriminative features from cross-domain samples. The reconstructed between-class scatter matrix aims to maximize the class separation of target samples, while the redefined within-class scatter matrix seeks to have samples from different domains densely clustered around the class center of target samples. Six widely used image datasets are involved to verify the effectiveness and efficiency of CFDC. Experimental results demonstrate that the performance of CFDC is significantly superior to similar methods and conventional unsupervised domain adaptation methods, comparable to non-deep semi-supervised domain adaptation methods, but with a significantly lower time consumption. Even compared with state-of-the-art deep semi-supervised domain adaptation methods, CFDC exhibits performance advantages on certain datasets. [ABSTRACT FROM AUTHOR]

We study the two-particle form-factors for the relativistic limit of the integrable S-matrix of the mixed-flux AdS3 × S3 × T4 string theory. The S-matrix theory was formally constructed in two distinct ways by two different teams. We focus on the massive theory built up by Frolov, Polvara and Sfondrini, and derive expressions for the minimal solutions to the axioms, in both integral and manifestly meromorphic form, and then proceed to apply the off-shell Bethe ansatz method of Babujian et al. We obtain the integral formulas for the two-particle complete form-factors and check the axioms at this particle number. [ABSTRACT FROM AUTHOR]

We study the two-particle form-factors for the relativistic limit of the integrable S-matrix of the mixed-flux AdS3 × S3 × T4 string theory. The S-matrix theory was formally constructed in two distinct ways by two different teams. We focus on the massive theory built up by Frolov, Polvara and Sfondrini, and derive expressions for the minimal solutions to the axioms, in both integral and manifestly meromorphic form, and then proceed to apply the off-shell Bethe ansatz method of Babujian et al. We obtain the integral formulas for the two-particle complete form-factors and check the axioms at this particle number. [ABSTRACT FROM AUTHOR]

Background: Ultrasound's real-time, high-resolution imaging, and accessibility at the point of care make it a valuable tool for diagnosing clavicle fractures, with growing evidence supporting its diagnostic accuracy compared to other imaging modalities. Objective: To assess the diagnostic utility of ultrasound in detecting clavicle fractures. Methods: A systematic review and meta-analysis were conducted by performing a comprehensive literature search in PubMed, Scopus, Web of Science, and Embase databases up to March 10, 2023, following established guidelines. Eligible studies that reported outcomes of interest were included, relevant data elements were extracted, and data analysis was performed using STATA software version 17.0. Results: Meta-analysis of seven included studies showed high-pooled sensitivity (0.94) and specificity (0.98) values for ultrasonography in diagnosing clavicle fractures, with low to moderate heterogeneity for sensitivity and high heterogeneity for specificity. Meta-regression and subgroup analyses revealed that pediatric studies had higher sensitivity but significantly lower specificity (P=0.01) compared to mixed or adult studies. Additional subgroup analysis in the pediatric group indicated decreased heterogeneity for specificity. Fagan plot analysis demonstrated favorable post-test probabilities for both positive and negative results across varying pre-test probabilities. Additionally, the likelihood ratio scatter matrix showed moderate to high test performance for both exclusion and confirmation purposes. Conclusion: The current literature supports ultrasound as a reliable imaging modality for detecting clavicle fractures. It offers accurate diagnosis without exposing patients, especially children, to radiation. [ABSTRACT FROM AUTHOR]

Studies have found that matrix metalloproteinase-9 (MMP-9) plays a significant role in cancer cell invasion, metastasis, and tumor growth. But it is a challenge to go for highly sensitive and selective detection and targeting of MMP-9 due to the similar structure and function of the MMP proteins family. Herein, a novel surface-enhanced Raman scattering (SERS) sensing strategy was developed based on the aptamer-induced SERS "hot spot" formation for the extremely sensitive and selective determination of MMP-9. To develop the nanosensor, one group of gold nanospheres was modified with MMP-9 aptamer and its complementary strand DNA1, while DNA2 (complementary to DNA1) and the probe molecule 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) were grafted on the surface of the other group of gold nanospheres. In the absence of MMP-9, DTNB located on the 13-nm gold nanospheres has only generated a very weak SERS signal. However, when MMP-9 is present, the aptamer preferentially binds to the MMP-9 to construct MMP-9–aptamer complex. The bare DNA1 can recognize and bind to DNA2, which causes them to move in close proximity and create a SERS hot spot effect. Due to this action, the SERS signal of DTNB located at the nanoparticle gap is greatly enhanced, achieving highly sensitive detection of MMP-9. Since the hot spot effect is caused by the aptamer that specifically recognizes MMP-9, the approach exhibits excellent selectivity for MMP-9 detection. Based on the benefits of both high sensitivity and excellent selectivity, this method was used to distinguish the difference in MMP-9 levels between normal and cancer cells as well as the expression of MMP-9 from cancer cells with different degrees of metastasis. In addition, this strategy can accurately reflect the dynamic changes in intracellular MMP-9 levels, stimulated by the MMP-9 activator and inhibitor. This strategy is expected to be transformed into a new technique for diagnosis of specific cancers related to MMP-9 and assessing the extent of cancer occurrence, development and metastasis. [ABSTRACT FROM AUTHOR]

This paper addresses certain distributional aspects of a scale-free scatter matrix denoted by R that is stemming from a matrix-variate gamma distribution having a positive definite scale parameter matrix B. Under the assumption that B is a diagonal matrix, a structural representation of the determinant of R is derived; the exact density functions of products and ratios of determinants of matrices possessing such a structure are obtained; a closed form expression is given for the density function of R. Moreover, a novel procedure is utilized to establish that certain functions of the determinant of the sample scatter matrix are asymptotically distributed as chi-square or normal random variables. Then, representations of the density function of R that respectively involve multiple integrals, multiple series and Gauss' hypergeometric function are provided for the general case of a positive definite scale parameter matrix, and an illustrative numerical example is presented. Cutting-edge mathematical techniques have been employed to derive the results. Naturally, they also apply to the conventional sample correlation matrix which is encountered in various multivariate inference contexts. [ABSTRACT FROM AUTHOR]

Using the CST Microwave Studio 2023, models of plasmonic graphene antennas (PGAs) with excitation by using discrete and waveguide ports by incident TEM-waves of S- and P-polarization have been constructed. The characteristics of rectangular and square PGAs with dielectric and metallized substrate: scattering matrix elements, radiation patterns for various graphene parameters and chemical potential values have been calculated. [ABSTRACT FROM AUTHOR]

This contribution is devoted to discussion of questions related to the influence of a possible contribution from a bulk material on the lineshape of elastic peaks observed in diffraction experiments at neutron and/or X-ray radiation scattering on nanoporous matrices containing substances embedded into their porous space (channels). The proposed algorithm permits to estimate the input of massive component into diffraction peaks using the analysis of the experimentally observed distortions of the lineshape of Bragg peaks. This preliminary analysis greatly simplifies the profile analysis of nanocomposite diffraction patterns, especially for molecular sieves based on powders of SBA-15, MCM-41, MCM-48, etc., types. [ABSTRACT FROM AUTHOR]

Quantum theory determines the evolution of quantum states between quantum jumps. Quantum theory also allows us to calculate rates of quantum jumps and, on a probabilistic level, the outcomes of those quantum jumps. Both quantum jumps and the continuous evolution of quantum states are important in the time evolution of quantum systems, and the scattering matrix ties those seemingly disparate concepts together. Indeed, quantum jumps are so essential in quantum dynamics that we should refocus discussion of a quantum ontology on the power and principal limitations of our knowledge about quantum jumps as encoded in the scattering matrix. On the one hand, one might argue that the lack of a dynamical resolution of quantum jumps indicates an inherent incompleteness of the theory. However, we would rather submit that quantum theory is complete and that the observations indicate a principal limitation to the description of the universe as a smoothly evolving dynamical system. The modern understanding of quantum jumps therefore calls for updates to the Copenhagen interpretation instead of modifications of quantum theory. [ABSTRACT FROM AUTHOR]

Environmental conditions, including temperature, humidity, and light, can impact the quality of drugs. Microwave-based approaches offer a fast and cost-effective way to detect quality variations, providing an alternative to traditional techniques in the pharmaceutical and cosmetic industries. This article proposes the use of a microwave sensor for monitoring the quality of pharmaceutical drugs at distinct temperature levels. A small planar sensor based on three hexagonal split ring resonators (TH-SRR) is fabricated. The design is manufactured on an FR-4 dielectric substrate. The sensor is tested on a 1000 mg paracetamol tablet, at temperatures ranging from 40 to 80 ∘ C. The Variation in the permittivity that characterizes product degradation is translated into a shift in the frequency of the scattering matrix elements. To validate the microwave approach, drug quality is examined with the laser-induced breakdown spectroscopy (LIBS) technique, an optical emission laser used for both qualitative and quantitative investigations of elements contained in a sample. The existing elements are classified using the National Institute of Standards and Technology (NIST) database and categorized according to their spectral line wavelengths. The experiments show the presence of optimal wavelength values for carbon (C), hydrogen (H), nitrogen (N), and oxygen (O) at 247.92 nm, 656.49 nm, 244.23 nm, and 777.48 nm, respectively. The microwave experimental results show a shift frequency of approximately 1 MHz on average when the tablet is heated at 80 ∘ C for 15 min. Meanwhile, the LIBS measurement shows a remarkable shift in terms of intensity of approximately 8884 and 812 for carbon and hydrogen, respectively. Understanding how paracetamol dries under high temperatures and improving the process settings of the microwave sensor are investigated and assessed in this work. [ABSTRACT FROM AUTHOR]

Human activity recognition (HAR) is one of the key applications of health monitoring that requires continuous use of wearable devices to track daily activities. The most efficient supervised machine learning (ML)-based approaches for predicting human activity are based on a continuous stream of sensor data. Sensor data analysis for human activity recognition using conventional algorithms and deep learning (DL) models shows promising results, but evaluating their ambiguity in decision-making is still challenging. In order to solve these issues, the paper proposes a novel Wasserstein gradient flow legonet WGF-LN-based human activity recognition system. At first, the input data is pre-processed. From the pre-processed data, the features are extracted using Haar Wavelet mother- Symlet wavelet coefficient scattering feature extraction (HS-WSFE). After that, the interest features are selected from the extracted features using (Binomial Distribution integrated-Golden Eagle Optimization) BD-GEO. The important features are then post-processed using the scatter plot matrix method. Obtained post-processing features are finally given into the WGF-LN for classifying human activities. From these experiments, the results can be obtained and showed the efficacy of the proposed model. [ABSTRACT FROM AUTHOR]

The primitive Wigner-Seitz cell and corresponding first Brillouin zone (FBZ) are typically used in calculations of lattice vibrational and transport properties as they contain the smallest number of degrees of freedom and thus have the cheapest computational cost. However, in complex materials, the FBZ can take on irregular shapes where lattice symmetries are not apparent. Thus, conventional cells (with more atoms and regular shapes) are often used to describe materials, though dynamical and transport calculations are more expensive. Here we discuss an efficient anharmonic lattice dynamic method that maps conventional cell dynamics to primitive cell dynamics based on translational symmetries. Such symmetries have not been utilized in typical lattice dynamical calculations. This leads to phase interference conditions that act like conserved quantum numbers and a conservation rule for phonon scattering that is hidden in conventional dynamics which significantly reduces the computational cost. We demonstrate this method for phonon transport in a variety of materials with inputs from first-principles calculations and attribute its efficiency to reduced scattering phase space and fewer summations in scattering matrix element calculations. [ABSTRACT FROM AUTHOR]

A vector method for recording phase-dynamic radio images is proposed by forming and numerically analyzing the S-parametric scattering matrix of multidisciplinary signatures of material media and objects. The key advantages of aperture capture of signal radio images by the method of a frequency-synthesized power spectral density function of a scattered wave radio profile are determined. On the basis of a vector analyzer of microwave circuits and broadband antennas of the Vivaldi type, an experimental laboratory installation for signal registration of time-scale radio images in the spectral region of 0.03–6.0 GHz has been built. The dependences of the influence of the angular characteristics of the object on the spectral-temporal structure of the formation of phase-dynamic radio images have been experimentally established. As the time-scale postprocessing of radio images, a method of cepstral transformation of S-parametric characteristics with convolution of basic signatures in the radiogenic part of the irradiated object is proposed. A series of cepstral convolutions of phase-dynamic radio images was obtained, establishing a functional relationship between the change of the signature of an object in time with its radio genome. [ABSTRACT FROM AUTHOR]

Abstract—An experimental method was developed to determine losses in microstrip and coplanar transmission lines for devices operating in the frequency range of 77–81 GHz. The parameters of the scattering matrices are obtained using a vector network analyzer and frequency upconverters. The calculation of losses in waveguide-coplanar and coplanar-microstrip adapters is made. [ABSTRACT FROM AUTHOR]

Curved channels with constant cross sections are constructed which support a trapped surface wave. Since corresponding eigenvalues are embedded in the continuous spectrum of the water wave problem and therefore possess the natural instability, the construction procedure requires "fine-tuning" of several parameters in the (small) curvature of the channel as well as geometrical restrictions on the cross section. In particular, the mirror symmetry of the cross section with respect to the vertical axis disrupts the procedure, but examples of suitable non-symmetric cross sections are provided. [ABSTRACT FROM AUTHOR]

With the aid of the reciprocal transformation and the associated equation, we study the inverse scattering transform with a matrix Riemann–Hilbert problem for the modified Camassa–Holm (mCH) equation with nonzero boundary conditions (NZBC) at infinity. In terms of a suitable uniformization variable, the direct and inverse scattering problems are presented for the associated modified Camassa–Holm (amCH) equation. By means of the reciprocal transformation and the reconstruction formula for the potential of the amCH equation, we present the -soliton solution for the mCH equation with NZBC. As applications, various solutions including both bright and dark types, smooth soliton solutions, singular soliton solutions, and multi-valued singular soliton solutions of the mCH equation and their interactions are exhibited. [ABSTRACT FROM AUTHOR]

Within the class of Dereziński–Enss pair-potentials which includes Coulomb potentials and for which asymptotic completeness is known (Dereziński in Ann Math 38:427–476, 1993), we show that all entries of the N-body quantum scattering matrix have a well-defined meaning at any given non-threshold energy. As a function of the energy parameter the scattering matrix is weakly continuous. This result generalizes a similar one obtained previously by Yafaev for systems of particles interacting by short-range potentials (Yafaev in Integr Equ Oper Theory 21:93–126, 1995). As for Yafaev's paper we do not make any assumption on the decay of channel bound states. The main part of the proof consists in establishing a number of Kato-smoothness bounds needed for justifying a new formula for the scattering matrix. Similarly we construct and show strong continuity of channel wave matrices for all non-threshold energies. Away from a set of measure zero we show that the scattering and channel wave matrices constitute a well-defined 'scattering theory', in particular at such energies the scattering matrix is unitary, strongly continuous and characterized by asymptotics of generalized eigenfunctions of minimal growth. [ABSTRACT FROM AUTHOR]

In this research paper, we consider the process of neutral Higgs production from e+e– annihilation in Inert Higgs Doublet Model (IHDM) in the absence and presence of an external field. The latter is assumed to be a plane and monochromatic wave with linear polarization. In the theoretical framework, we present the analytic calculation of the lowest order differential cross section by using the scattering matrix approach and Dirac–Volkov formalism for charged incident particles. The total cross section is computed by performing a numerical integration of the differential cross section over the solid angle. The results obtained are analyzed and discussed for different centre of mass energies and laser parameters. We found that inserting a laser wave with linear polarization is a suitable mechanism to enhance the total cross section of the process. Indeed, the probability of the process to occur increases with the presence of a linearly polarized laser field, especially with low frequency and high strength. [ABSTRACT FROM AUTHOR]

Early intervention for depression could provide a means to reducing the disease burden, but there is a lack of objective diagnostic methods. This study investigated automatic depression classification on a speech dataset of 85 healthy controls (51 females and 34 males) and 85 depressed patients (53 females and 32 males). Considering that there are obvious differences in the performance of different types of speech features, we propose a radius-incorporated localized multiple kernel learning (trLMKL) algorithm for detecting depression in speech to make the best use of speech features. To improve the classification accuracy, we combine the information of both the margin and the radius of the MEB to learn the gating model parameters in our algorithm. Furthermore, we do not directly incorporate the radius of the MEB, but incorporate the trace of the total scattering matrix of training data. This method can avoid the time cost of calculating the radius at each iteration and decrease the computational complexity. Comprehensive experiments were carried out on our depressed speech dataset and 10 UCI datasets. Our algorithm achieved better classification performance overall than SimpleMKL and LMKL, and it was efficient at detecting depression, indicating its potential for use as a diagnostic method for depression. [ABSTRACT FROM AUTHOR]

For a provenance study and characterization of different types of sedimentological processes that affect weathering, information on chemical weathering of sediments is critical. Major elements of sedimentary geochemistry can be estimated by using the various weathering indices (WIs) models. The present study is a fair attempt in the development of a web dashboard–SedWeather to analyze chemical weathering of sediments using major elemental geochemistry. It offers a flexibility to constrain sediments and rock composites and to demonstrate weathering profiles & source rock chemical makeup in various compositional space diagrams including Al2O3–CaO-Na2O–K2O, Al2O3–CaO-Na2O-K2O–Fe2O3-MgO, M–F–W; illustrates different various weathering indices (WIs) including CIW, CPA, CIA, PIA, CIX, ICV, WIP and W in boxplots, scatter matrix, correlation matrix against major oxides and ratios. It is possible to alter the Python code in accordance with the data and user requirement by altering the arguments and adding more relevant charts and plots to fit the data. SedWeather's performance in evaluating chemical weathering is demonstrated by evaluating sediments of Surma and Barail sandstones, Mizoram Foreland Basin, NE India, sediments of Manasbal lake, Kashmir, India, and channel sediments, overbank sediments, suspended sediments of the Ganga basin, having their own provenance history. [ABSTRACT FROM AUTHOR]

Using the extended scattering matrix method, the authors explore the interference of edge states in the nanoribbon resonant structure with the relativistic quasiparticles in the quantum limit. By varying the chemical potential in the gated region, the structure of the junction, and the number of the scattering impurities/defects, the scattering coefficients of the edge states can be tuned efficiently. In particular, the Fabry–Pérot like interference in the present structure has been found and the phase accumulated highly depends on both the modes propagating vertically to the interface and the modes propagating along the interface. The feature is fundamentally different from the case of the conventional material where the longitudinal resonant states of the narrow constriction give rise to a clear conductance dips. These results are crucial and useful for engineering nanoelectronic devices based on the relativistic quasiparticles systems. [ABSTRACT FROM AUTHOR]

We study the interactions of systems of two and three nondegenerate mesons composed of pions and kaons at maximal isospin using lattice QCD, specifically π+K+, π+π+K+ and K+K+π+. Utilizing the stochastic LapH method, we determine the spectrum of these systems on two CLS Nf = 2 + 1 ensembles with pion masses of 200 MeV and 340 MeV, and include many levels in different momentum frames. We constrain the K matrices describing two- and three-particle interactions by fitting the spectrum to the results predicted by the finite-volume formalism, including up to p waves. This requires also results for the π+π+ and K+K+ spectrum, which have been obtained previously on the same configurations. We explore different fitting strategies, comparing fits to energy shifts with fits to energies boosted to the rest frame, and also comparing simultaneous global fits to all relevant two- and three-particle channels to those where we first fit two-particle channels and then add in the three-particle information. We provide the first determination of the three-particle K matrix in π+π+K+ and K+K+π+ systems, finding statistically significant nonzero results in most cases. We include s and p waves in the K matrix for π+K+ scattering, finding evidence for an attractive p-wave scattering length. We compare our results to Chiral Perturbation Theory, including an investigation of the impact of discretization errors, for which we provide the leading order predictions obtained using Wilson Chiral Perturbation Theory. [ABSTRACT FROM AUTHOR]

The main objective of this work is to isolate Effective Field Theory scattering amplitudes in the space of non-perturbative two-to-two amplitudes, using the S-matrix Bootstrap. We do so by introducing the notion of Effective Field Theory cutoff in the S-matrix Bootstrap approach. We introduce a number of novel numerical techniques and improvements both for the primal and the linearized dual approach. We perform a detailed comparison of the full unitarity bounds with those obtained using positivity and linearized unitarity. Moreover, we discuss the notion of Spin-Zero and UV dominance along the boundary of the allowed amplitude space by introducing suitable observables. Finally, we show that this construction also leads to novel bounds on operators of dimension less than or equal to six. [ABSTRACT FROM AUTHOR]

The purpose of this study is to model the characteristics (scattering matrix element |S11| and 2D and 3D radiation patterns (RPs)) of phased-array antennas (PAAs) composed of graphene-based nanoribbon elements with different numbers of emitters (N = 16, 64, and 256) and analyze their controllability under variable chemical potential (application of an external electric field) in the terahertz and far-IR frequency ranges using the CST Studio Suite 2021 software package. The characteristics (scattering matrix and 2D and 3D RPs) of a graphene antenna and a PAA composed of graphene nanoribbon elements with a different number of emitters (N = 16, 64, and 256) and the controllability of the PAA depending on the chemical potential (µc = 0.3, 0.7, and 1 eV) in the frequency range f = 6–40 THz are simulated using the CST Studio Suite 2021 software. As follows from the electrodynamic simulation results, a change in the graphene chemical potential leads to changes in the PAA characteristics (half-power main lobe width , its amplitude, side-lobe level, direction of the RP main lobe, and operating frequencies). Phased-array antennas composed of rectangular graphene nanoribbon elements can be electrically controlled with frequency scanning by changing chemical potential µc (by applying an external electric field) in the terahertz, far-IR, and mid-IR frequency ranges. [ABSTRACT FROM AUTHOR]

Anisotropy is ubiquitous in the Earth's crust, which causes the elastic characteristics of seismic waves to change with direction. The study of seismic wave anisotropy is of great significance to seismic exploration, prediction and geodynamics. As one of the sources of seismic anisotropy, in situ stress belongs to secondary anisotropy as common as the intrinsic and fracture-induced anisotropy, but it is often ignored among the sources of seismic anisotropy. Therefore, we focus on the study of seismic anisotropy under the influence of in situ stress using the nonlinear acoustoelasticity theory. Based on a horizontal transversely isotropic (HTI) model and the linear slip theory, the characteristics of azimuthal seismic reflection response in anisotropic media under horizontal in situ stress are discussed in this paper. Firstly, by using the quasi-linear relationship between stress and Tsvankin's anisotropic parameters and the transformation relationship between anisotropic and fracture parameters in HTI medium, the elastic stiffness matrix of an HTI medium with the effect of horizontal in situ stress is established. Secondly, the reflection coefficient of PP-wave seismic data for a planar weak-contrast interface separating two weak-anisotropy and small-stress HTI half-spaces is derived using both the seismic scattering theory and the stiffness matrix under horizontal in situ stress, building the quantitative relationship between azimuthal seismic reflection characteristics and the model parameters, such as the background elastic parameters, the fracture parameters and the horizontal-stress-induced anisotropic parameters. Finally, the variation rules of azimuthal seismic reflection response characteristics of four elastic interfaces under different in situ stress conditions are analyzed. The results demonstrate that the seismic inversion for fracture parameters and horizontal-stress-induced anisotropic parameters is more favorable under the condition of large incident angle. In addition, the effect of horizontal in situ stress on the reflection coefficient depends on the second- and third-order elastic properties of the rock itself. Also, the established seismic PP-wave reflection coefficient equation has provided an alternative approach to calculate the magnitude of horizontal in situ stress. Article Highlights: A novel linearized PP-wave reflection coefficient is presented for HTI media with the effect of horizontal in situ stress The response law of azimuthal seismic reflection characteristics induced by horizontal in situ stress is demonstrated A simple inversion method is provided to calculate the magnitude of horizontal in situ stress [ABSTRACT FROM AUTHOR]

The asymptotic behavior of the solution of the scattering problem for three three- dimensional Coulomb quantum particles in a neighborhood of the three-particle forward scattering direction is considered. [ABSTRACT FROM AUTHOR]

Understanding substrate effects on spin dynamics and relaxation is of key importance for spin-based information technologies. However, the key factors that determine such effects, in particular for materials with strong spin-orbit coupling (SOC), have not been well understood. Here we performed first-principles real-time density-matrix dynamics simulations with SOC and the electron-phonon and electron-impurity scattering for spin lifetimes (τs) of supported/free-standing germanene, a prototypical strong SOC 2D Dirac material. We show that the effects of different substrates on τs can surprisingly differ by two orders of magnitude. We find that substrate effects on τs are closely related to substrate-induced modifications of the SOC-field anisotropy, which changes the spin-flip scattering matrix elements. We propose a new electronic quantity, named spin-flip angle θ↑↓, to characterize spin relaxation through intervalley spin-flip scattering. We find that τ s − 1 is approximately proportional to the averaged value of sin 2 θ ↑ ↓ / 2 , which serves as a guiding parameter of controlling spin relaxation. [ABSTRACT FROM AUTHOR]

In some real applications, it requires to recognize known class(es) as well as unknown class. Traditional classification can only recognize the known class(es) which occur(s) in the training set. Recently, Kernel Null Foley-Sammon Transformation (KNFST) is proposed to overcome the weakness that traditional classification cannot identify unknown class. In KNFST, the samples from the same class are mapped to a point via null projected directions. For a test sample, the predicted label is the class with the minimum distance to it in the projected space. If the test sample is far away from all projected points, it comes from an unknown class. However, KNFST only considers the global information which is depicted by between- and within- class scatter matrices. When the internal structure is complex, KNFST may fail. In order to handle this issue, this paper proposes a Kernel Null Regularized Foley-Sammon Transformation (KNRFST) by introducing a regularized term into KNFST. The regularized term is depicted by a neighborhood which consists of reverse nearest neighbors. The neighborhood can depict the local information in the class. The experimental results, performed on several datasets, show that KNRFST is superior to some previous methods, including KNFST, Local KNFST, WOC-SVM, Deep SVDD and OCC-GAN. [ABSTRACT FROM AUTHOR]

This paper presents a new facial feature extraction method on entropy based fractional fuzzy generalized two-dimensional linear discriminant analysis (EnFFG-2DLDA) where the concept of class uncertainty is incorporated within the generalized two-dimensional linear discriminant analysis. The EnFFG-2DLDA achieves the optimal projection matrix (in both directions) by maximizing the entropy and fuzzy membership value, based on inter-class similarity, while minimizing intra-class discrepancy by integrating weight function. This method ameliorates the shortcomings of 2DLDA method, which fails in case of many real-world situations as it focuses on the global relationship of data, and relies on Gaussian distributed data. Our EnFFG-2DLDA method does not depend on the assumptions that the data distributions and it exploits the intrinsic local structure of the data. Moreover, the FkNN has been incorporated into G-2DLDA algorithm to highlight distinguishable features by redefining the intra- (within) and inter- (between) class scatter matrices along horizontal (row) and vertical (column) directions. The global and per-class mean training vectors are regenerated by combining the fuzzy membership values. The weighting function is associated into inter class scatter matrix, in both direction, to solve contour based problem. Finally, Entropy membership values are specifically used for measuring uncertainty in the special variation in a facial image. Therefore, more significant feature information have been distilled out by combining FkNN, weight function and entropy with the G-2DLDA method, which solves the multi-classification problem. The feasibility of fractional fuzzy G-2DLDA with entropy membership value has been validated over frontal, occluded, and rotationally- angled images with four public standard face databases using RBF neural network. The investigational results demonstrate the substantial accuracy of 99.06% (k = 6) for ORL, 97.81% (k = 10) for UMIST and 66.04 (k = 4) for FERET dataset in terms of average recognition accuracy. [ABSTRACT FROM AUTHOR]

Multi band, high spatial resolution and information redundancy are the most significant characteristics of hyperspectral image. These remarkable characteristics are mainly caused by the high-dimensional image data. In view of these characteristics, feature extraction of hyperspectral image has naturally become one of the research hotspots in this field. However, it is impossible to fully describe the intrinsic geometric structure of hyperspectral image only by using spectral information. To improve the subsequent forecasting accuracy, spatial information should be mined to further describe the geometric structure of hyperspectral image. Therefore, an effective feature extraction method (SSF_HM) was proposed via using harmonic mean and spectral-spatial filter. This investigation divides the SSF_HM into three steps. First, the pi principal components were extracted by using principal components analysis (PCA) skill and subsequent the pi spatial filtering features were obtained via using area median filter (AMF) method. Then, the original spectral features and extracted spatial filtering features combine to form the fusion feature matrix, and then the scatter matrix S b H M (based on harmonic mean (HM) spectral-spatial filter inter-class) and scatter matrix S w H M (based on harmonic mean (HM) spectral-spatial filter intra-class) can be established in the fusion feature space, respectively. Finally, combining the Fisher discriminant analysis model and regularization technique, a new feature extraction method SSF_HM is developed. The proposed SSF_HM method combines spectral information and spatial information. At the same time, the range of feature extraction is expanded from spectral space to spectral-spatial fusion space. The experimental results on three real-world hyperspectral image data sets show the better performance of SSF_HM in comparison with other feature extraction methods in small sample size situation by using maximum likelihood classifier (MLC). [ABSTRACT FROM AUTHOR]

To solve the problem that the existing semi-supervised FISHER discriminant analysis algorithm (FDA) cannot effectively use both labeled and unlabeled data for learning, we propose a semi-supervised Kernel local FDA Algorithm based on density peak clustering pseudo-labels (SDPCKLFDA). First, the proposed algorithm adopts the density peak clustering algorithm to generate the pseudo cluster labels for labeled and unlabeled data, and then the generated pseudo-labels are explored to construct two regularization strategies. The two regularization strategies are used to regularize the corresponding within-class scatter matrix and between-class scatter matrix of the local Fisher discriminant analysis, and finally the optimal projection vector is obtained by solving the objective function of the local Fisher discriminant analysis. The two constructed regularization strategies can not only effectively enhance the discriminant performance of the extracted feature but also make the proposed algorithm suitable for multimodal and noisy data. In addition, to accommodate nonlinear and non-Gaussian datasets, we also develop a kernel version of the proposed algorithm with the help of kernel trick. In the experiment, the proposed algorithm is compared with the FDA and its improved algorithms on some benchmark artificial datasets and UCI datasets. The experimental results show that the discriminant performance of the proposed algorithm has been significantly improved compared with the other algorithms. [ABSTRACT FROM AUTHOR]

We present wave-based signal differentiation with unprecedented fidelity and flexibility by purposefully perturbing overmoded random scattering systems such that zeros of their scattering matrices lie exactly at the desired locations on the real frequency axis. Our technique overcomes limitations of hitherto existing approaches based on few-mode systems, both regarding their extreme vulnerability to fabrication inaccuracies or environmental perturbations and their inability to maintain high fidelity under in-situ adaptability. We demonstrate our technique experimentally by placing a programmable metasurface with hundreds of degrees of freedom inside a 3D disordered metallic box. Regarding the integrability of wave processors, such repurposing of existing enclosures is an enticing alternative to fabricating miniaturized devices. Our over-the-air differentiator can process in parallel multiple signals on distinct carriers and maintains high fidelity when reprogrammed to different carriers. We also perform programmable higher-order differentiation. Conceivable applications include segmentation or compression of communication or radar signals and machine vision. Here, the authors report purposefully perturbed wave chaos that enables analog signal processing with unprecedented fidelity and flexibility. [ABSTRACT FROM AUTHOR]

We evaluate theoretically the interaction of the open bottom and strange systems B ¯ K ¯ , B ¯ ∗ K ¯ , B ¯ K ¯ ∗ and B ¯ ∗ K ¯ ∗ to look for possible bound states which could correspond to exotic non-quark–antiquark mesons since they would contain at least one b and one s quarks. The s-wave scattering matrix is evaluated implementing unitarity by means of the Bethe–Salpeter equation, with the potential kernels obtained from contact and vector meson exchange mechanisms. The vertices needed are supplied from Lagrangians derived from suitable extensions of the hidden gauge symmetry approach to the bottom sector. We find poles below the respective thresholds for isospin 0 interaction and evaluate the widths of the different obtained states by including the main sources of imaginary part, which are the B ∗ → B γ decay in the B ¯ ∗ K ¯ channels, the K ∗ → K π in the channels involving a K ∗ , plus the box diagrams with B ¯ K ¯ and B ¯ ∗ K ¯ intermediate states for the B ¯ ∗ K ¯ ∗ channels. [ABSTRACT FROM AUTHOR]

The internal meanflow with nonuniform distributions of velocity and temperature is a major challenge for acoustic analysis of a muffler in the frequency domain. On the other hand, the three-dimensional time-domain numerical method is well suited for solving the influence of meanflow on the muffler, but it is time-consuming, especially for calculating the transfer matrix that requires two sets of boundary conditions. We proposed a more efficient time-domain method to calculate the scattering matrix (SM) of an actual engine muffler using a numerical model with only one set of boundary conditions. The reciprocity, as a basic property of waves, was for the first time demonstrated in such a complex muffler with hot nonuniform flow exhausted from the engine and used to reduce the procedures for calculating the SM. The reciprocal relationship was not only expressed in the modules of the transmission coefficients in the SM but also corrected in the phases using the time delay between the incident and transmitted waves observed with the time-domain method. At last, the SM was adopted to obtain the performance of the muffler, which was validated with the measurement. The proposed method shall make the time-domain method more efficient for calculating the characterizing matrix of a muffler without or with meanflow. [ABSTRACT FROM AUTHOR]

The paper considers an infinite two-dimensional ultra-wideband two-section antenna array in which the first section is made in the form of an isolated block connected to the second section via a special transition. Based on an approximate solution of a boundary value problem, an analytical model of the transition, making it possible to calculate its scattering matrix, is constructed. The scattering and transfer matrices of the first and second sections of the array in the quasi-periodic excitation mode are found in the approximation of the theory of microwave transmission lines. The total transfer matrix of the entire array is determined by multiplying the transfer matrices of its components. The numerically constructed analytical model of the array makes it possible to calculate its scattering matrix in the scan mode and has a high computational efficiency. The results of calculations by the proposed approximate model are compared with the results given by rigorous full-wave methods. [ABSTRACT FROM AUTHOR]

For a unitary unramified genuine principal series representation of a covering group of a simply-connected group, we studied in a previous paper a conjectural formula relating its R-group to the dimension of the Whittaker space of the irreducible constituents. In this paper, the formula is refined and also verified for several important cases. [ABSTRACT FROM AUTHOR]

In this paper, we propose a Regge-pole model with a Gaussian potential to study hadron scattering at high energies. In the diffraction approximation, considering the consequences of the analyticity and unitarity of the scattering amplitude, expressions are obtained for the matrix of the scattering amplitude, the cross section, and the slope of the diffraction cone for reactions a + A → B + b. The resulting expressions are applied to p-p scattering. The results obtained show that the model describes well the slope coefficient of the diffraction cone at energies below 102 GeV. To obtain agreement with the experiment at high energies, the parameters should be adjusted. [ABSTRACT FROM AUTHOR]

The influence of the geometry of a TEM horn being a part of the infinite cophased array of irregular horns with the metallized interhorn space on the matching band of the array is investigated. The frequency dependences of the reflection coefficient are analyzed within the framework of the smooth transition in the Floquet channel for different laws of the change of the wave impedance. This analysis is performed with the use of the following two methods of the waveguide theory: the cross-section method and the scattering matrix method. In addition, the numerical modeling with the use of the finite element method is applied. [ABSTRACT FROM AUTHOR]

Mining knowledge from imbalanced data is challenging due to the uneven distribution of classes and increasing dimensionality of data accumulated from real-life applications. Selecting informative features from imbalanced data is especially important for building an effective learning method. The global redundancy and the effect of imbalanced distribution need to be considered simultaneously. In this study, a feature selection method that considers the imbalanced distribution of classes in data is investigated by embedding the weighted constraint on the majority class into the global redundancy minimization GRM framework. Global redundancy minimization is acquired through an objective function that contains a feature redundancy matrix and feature scores. A new form of regularization to a within-class scatter matrix is first presented, which emphasizes the minority class and replaces the redundancy measurement approach. Then, after employing this new form of a within-class scatter matrix in GRM and taking the between-class distance as the GRM input score, a GRM-based discriminant feature selection algorithm (GRM-DFS) is proposed. Comparison studies on a within-class scatter matrix with different forms of regularization indicate that the proposed form of a within-class scatter matrix is effective when dealing with imbalanced data. Experiments on public imbalanced datasets are performed. The experimental results indicate that GRM-DFS is effective. [ABSTRACT FROM AUTHOR]

A method is developed for the analysis of an infinite cophased ultrawideband array consisting of TEM horns. The method is based on the theory of long lines. The methods of scattering matrices and conformal mapping are used for the determination of the characteristic impedance in each section of the infinite cophased array. The algorithm realizing the conformal mapping method is presented. The calculation results obtained with the use of the suggested technique and electromagnetic modeling in the ANSYS HFSS software environment are compared. [ABSTRACT FROM AUTHOR]