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This paper proposes a complex boundary wave superposition method with a unique solution of full wavenumber based on the similarity between the acoustic wave superposition method (WSM) and the external excitation response of dynamic systems and combined with the idea that a damping system has a unique solution in dynamic theory. By placing the virtual equivalent source on the virtual boundary of complex space, the conventional WSM acquires damping properties comparable to those of the dynamical system. This approach successfully addresses the non-uniqueness of the solution at the eigenfrequency and is more efficient than the conventional combined layer potential method. The paper presents a comprehensive description of the proposed method, with a focus on theory, modeling, and parameter selection. The effectiveness of this method is evaluated by applying it to two types of acoustic problems, namely, radiation and scattering. The numerical results indicate that this method effectively addresses the non-unique problems encountered in conventional WSM. Furthermore, the proposed method is as accurate and efficient as the conventional WSM. [ABSTRACT FROM AUTHOR]

Copyright of Journal de Ciencia e Ingeniería is the property of Corporacion Universitaria Autonoma del Cauca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Metasurfaces have great advantages in the field of laser detection because of their ability to generate large amounts of point sources or various diffraction patterns. Here,cascaded metasurfaces (CM) for generating switchable spatial light distributions is utilized, which can be used for optical scanning and identifications. The light distribution is composed of several distinct diffraction patterns, and the scanning of the diffraction space is realized by multiple pixel‐scale alignment strategies between two pieces of CM. Through combining Dammann optimization and the gradient descent method, various diffraction patterns under different matching situations can be guaranteed by phase superposition. Various diffraction conditions with highly identifiable intensity distribution are guaranteed by using the optimization method. Such optical scanning devices based on CM have small footprints, high integration, flexible composition, and stable diffractive combination features. By manipulating CM to generate changeable spatial diffraction phenomenon may provide flexible modulation properties to optical scanning, measurement, and other applications. [ABSTRACT FROM AUTHOR]

For the measurement of the energy spectra generated by photons up to 320 keV (X-rays) that can be considered by the superposition of a set of monoenergetic photons, several types of detectors have been used, mainly Ge detectors. Each spectrum can be considered as the superposition of a beam of monoenergetic photons that contain a photoelectric peak, a Compton distribution, the characteristic radiation, and a multiple scattering region, which is located between the Compton edge and the photoelectric peak. In this article, a theoretical model is developed for finding the multiple scattering region. To this end, double Compton scattering is proposed, wherein the electron in motion after the first collision suffers a second Compton scattering by a photon going in the same direction. Using the theory of special relativity and the Lorentz invariants, the kinetic energy of the electron in motion is calculated. Then, with the obtained value and the new Klein–Nishina formula, the cross-section of the absorbed electrons is calculated as a function of its kinetic energy. The model fits correctly for the multiple scattering region from four sources with a conventional multichannel analyser and its associated electronics. [ABSTRACT FROM AUTHOR]

In this paper, I present a new analysis of the meaning of the phase in quantum mechanics. First, I give a simple but rigorous proof that the global phase is not real in ψ -ontic quantum theories. Next, I argue that a similar strategy cannot be used to prove the reality of the global phase due to the existence of the tails of the wave function. Finally, I argue that the relative phase is not a nonlocal property of two regions together, and adding a relative phase to one local branch of a superposition only changes the local properties at the boundary of the region of the branch. [ABSTRACT FROM AUTHOR]

In this work, we have studied the nuclear and electron dynamics in the glycine cation starting from localized hole states using the quantum Ehrenfest method. The nuclear dynamics is controlled both by the initial gradient and by the instantaneous gradient that results from the oscillatory electron dynamics (charge migration). We have used the Fourier transform (FT) of the spin densities to identify the "normal modes" of the electron dynamics. We observe an isomorphic relationship between the electron dynamics normal modes and the nuclear dynamics, seen in the vibrational normal modes. The FT spectra obtained this way show bands that are characteristic of the energy differences between the adiabatic hole states. These bands contain individual peaks that are in one-to-one correspondence with atom pair (+·) ↔ (·+) resonances, which, in turn, stimulate nuclear motion involving the atom pair. With such understanding, we anticipate "designer" coherent superpositions that can drive nuclear motion in a particular direction. [ABSTRACT FROM AUTHOR]

Photovoltaic power generation prediction constitutes a significant research area within the realm of power system artificial intelligence. Accurate prediction of future photovoltaic output is imperative for the optimal dispatchment and secure operation of the power grid. This study introduces a photovoltaic prediction model, termed ICEEMDAN-Bagging-XGBoost, aimed at enhancing the accuracy of photovoltaic power generation predictions. In this paper, the original photovoltaic power data initially undergo decomposition utilizing the Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (ICEEMDAN) algorithm, with each intrinsic mode function (IMF) derived from this decomposition subsequently reconstructed into high-frequency, medium-frequency, and low-frequency components. Targeting the high-frequency and medium-frequency components of photovoltaic power, a limiting gradient boosting tree (XGBoost) is employed as the foundational learner in the Bagging parallel ensemble learning method, with the incorporation of a sparrow search algorithm (SSA) to refine the hyperparameters of XGBoost, thereby facilitating more nuanced tracking of the changes in the photovoltaic power's high-frequency and medium-frequency components. Regarding the low-frequency components, XGBoost-Linear is utilized to enable rapid and precise prediction. In contrast with the conventional superposition reconstruction approach, this study employs XGBoost for the reconstruction of the prediction output's high-frequency, intermediate-frequency, and low-frequency components. Ultimately, the efficacy of the proposed methodology is substantiated by the empirical operation data from a photovoltaic power station in Hebei Province, China. Relative to integrated and traditional single models, this paper's model exhibits a markedly enhanced prediction accuracy, thereby offering greater applicational value in scenarios involving short-term photovoltaic power prediction. [ABSTRACT FROM AUTHOR]

The 2-D compact variational mode decomposition (2-D-C-VMD) has potential research significance in data mining of hyperspectral images (HSIs). The paper proposes a method of concatenation of features. First, the 2-D-C-VMD technique is used to decompose the HSIs to obtain smooth and clear boundary sub-band images when the 2-D-C-VMD takes the most preferred a priori parameter K ×. Second, the optimal low-frequency component features of the image and the optimal high-frequency component constructed features are concatenated first and last, and the structure of the concatenation is constructed into a new fused data. Finally, in order to avoid the redundancy of the fused data band information from affecting the classification result, combine a recently developed simple and practical superpixelwise principal component analysis (SuperPCA) dimensionality reduction method to effectively reduce the dimensionality of the fused data. By comparing the analysis with relying only on the optimal low-frequency image feature information and with the direct linear superposition fusion that has been employed, it is verified that the concatenation of features approach proposed in this paper can obtain better recognition results. [ABSTRACT FROM AUTHOR]

LAMOST J024048.51+195226.9 (J0240+1952) was recently identified as the second AE Aquarii (AE Aqr)-type cataclysmic variable, possessing the fastest known rotating white dwarf. We performed a Very Long Baseline Interferometry (VLBI) observation of J0240+1952 utilizing the European VLBI Network at 1.7 GHz, to obtain the first view of the radio morphology on mas scale. Our high-resolution VLBI image clearly shows that the radio emission is compact on mas scale (≲2 AU), with no evidence for a radio jet or extended emission. The compact radio source has an average flux density of ∼0.37 mJy, and its brightness temperature is given at ≳2.3 × 107 K, confirming a non-thermal origin. The emission exhibits irregular variations on a time-scale of tens of minutes, similar to the radio flares seen in AE Aqr. The measured VLBI position of J0240+1952 is consistent with that derived from Gaia. Our results favour the model in which the radio emission is attributed to a superposition of synchrotron radiation from expanding magnetized blobs of this system. [ABSTRACT FROM AUTHOR]

Two-dimensional layered transition metal dichalcogenides (TMDCs) offer the ideal platform to optically initialize the qubits utilizing the superposition of valley polarized photons. However, in the commonly available 2H phase TMDCs, thickness sensitive crystal inversion symmetry demands the precise control over the number of layers, which makes the study of valley physics challenging. On the other hand, 3R-polymorphic phase TMDCs are non-centrosymmetric irrespective of the number of layers and therefore retain valley degree of freedom for all the thicknesses. Here, using polarization resolved photoluminescence measurements under linearly polarized excitations, we demonstrate the coherent superposition of the valley photons (known as valley coherence) in synthetic 3R-phase MoS2 with different numbers of layers ranging from 3 layers to 11 layers. With near-resonant excitation (633 nm for AX0), the degree of linear polarization (a measure of the valley coherence) is observed up to 70% at 80 K measurement temperatures and is found to be layer thickness independent. Robust valley coherence is attributed to the high optical quality and the 3R crystal symmetry of the MoS2. Using angle resolved polarization dependent measurements, it is established that the net dipolar emission aligns with the polarization orientations of the incident laser, which signifies the valley coherence to be independent of the crystal orientation. This study paves the way toward using 3R-phase MoS2 as a key material for the development of future quantum technologies utilizing valley polarized photons. [ABSTRACT FROM AUTHOR]

Ultra-wideband (UWB) applications require lowpower and low-noise amplifiers (LNAs) that can operate over a wide frequency range. However, conventional LNAs often suffer from poor linearity and high-power consumption. This research work proposes a novel LNA design that uses the adjusted derivative superposition (DS) technique and feedback to improve the linearity and reduce the power consumption of UWB LNAs. The DS technique enhances the third-order intermodulation (IM3) cancellation by adjusting the bias currents of the transistors, whereas the feedback improves the stability and input matching of the LNA. The LNA is implemented using a degenerated common source topology in a 180 nm standard CMOS technology. The simulation results show that the LNA achieves a power gain of 10-12.2 dB, an input thirdorder intercept point (IIP3) of about 12 dBm, and a noise figure of less than 2.5 dB over the UWB frequency band of 3.1-10.6 GHz. The input reflection coefficient is less than -10 dB, and the power consumption is 11.6 mW with a 1.5 V power supply. The designed LNA offers a novel and innovative solution for UWB applications that significantly improve the performance and efficiency of UWB LNAs whereas reducing the cost and complexity of implementation. [ABSTRACT FROM AUTHOR]

Canonical coherent states of a quantum harmonic oscillator have been generalized by requiring the conditions of normalizability, continuity in the label and resolution of the identity operator with a positive weight function. Superpositions of these states are considered in the present scenario as a generalization of the optical Schrödinger cat states. The Fock space is assumed to be canonical or finite-dimensional. The photon number distribution of these generalized Schrödinger cat states departs from the Poisson statistics in various ways for high photon numbers. For small nonvanishing values of the label, the photon number distribution is sub-Poissonian (nonclassical) or super-Poissonian, according to the interference properties. In fact, the sub- or super-Poissonian statistics is determined by the interplay between the relative phase and a critical value of the phase. The photon number distribution is uniquely sub-Poissonian for large values of the label. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University (English Edition) is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Superlens slabs rely on the coherent superposition of multiply reflected evanescent waves to amplify and restore the fine details of an object at the image plane. If a superlens slab is placed in close proximity to a source object and image detector, similar interactions with these external components can introduce resonances outside of the superlens. In this work, we explore the role of external resonances on single-negative slab superlens performance by considering a complete electromagnetic imaging system containing a physical source object and image detector, each modeled as a planar dielectric half-space. In studying the transmission of spectral components that carry real power through this system, we find that resonances outside the lens can have a dramatic impact on single-negative superlens performance. In particular, we find that the resonances external to a μ -negative lens can be used to extend the imaging range beyond the extreme near field and maintain super-resolution even in the presence of loss. [ABSTRACT FROM AUTHOR]

Here, we present an unexplored issue regarding temporal aggregation. When a model contains frequency‐dependent coefficients, such as a distinct long‐ and short‐term coefficient, temporal aggregation leads to inconsistent least squares estimates. Because the sub‐sampled variable's spectrum is equal to its folded original spectrum, the low‐frequency variable may exhibit a mixture of distinct linear relations for a given frequency. We propose a new method to disentangle the frequencies superposition based on band spectrum regression, thus avoiding the inconsistency problem. As a result, we can test for the presence of frequency‐dependent coefficients. We use stationary and non‐stationary linear semi‐parametric models to demonstrate our findings. Our Monte Carlo simulations show good finite sample size and power properties. Finally, our empirical study rejects the presence of a single coefficient for all frequencies between quarterly GDP and monthly US indicators. [ABSTRACT FROM AUTHOR]

The interaction of a single-mode quantized light field with a low-dissipative nonlinear medium is analyzed in case the field mode is initially prepared in a generalized coherent state (GCS). Similarly to the case of canonical coherent states (CSs) of light, the time evolution is periodic and becomes a superposition of a finite number of GCSs at determined time instants. The effects of the dissipative process on these superpositions are studied by evaluating the loss of one photon and the corresponding rate. Special conditions are determined such that the superpositions of GCSs created in the time evolution of a GCS are stronger or weaker against the dissipative process than the superpositions of optical CSs generated in the evolution of a canonical CS. This selection is performed by comparing the corresponding dissipation rates of loosing one photon. In this way, perturbations of coherent light are found such that the quantum superpositions of GCSs created in the time evolution are stronger against the dissipative process than the superpositions of optical CSs generated with coherent light. [ABSTRACT FROM AUTHOR]

We consider sharp focusing of an axial superposition of two optical vortices with identical topological charges, but different amplitudes and circular polarizations of different signs. The ratio of the amplitudes of the two beams is a parameter. When this parameter changes, the polarization state of the superposition changes from linear polarization to right-hand circular polarization. Based on the Richards–Wolf theory, exact expressions are obtained for the longitudinal components of the spin angular momentum (SAM) density and orbital angular momentum (OAM) density at the focus of the considered superposition. It follows from these expressions that the sum of the total longitudinal components of the SAM and OAM is conserved upon focusing, and also that, due to the spin-orbit conversion, the total longitudinal component of the SAM decreases during focusing, while the total longitudinal component of the OAM increases by the same amount. By changing the ratio of the amplitudes of the constituent beams from 1 to 0, one can change the value of the spin-orbit conversion from zero (for linear polarization) to a maximum (for circular polarization). Also, by changing this parameter, one can control the spin Hall effect at the focus, which takes place at the focus of the considered beam. This study can be applied for controlling the rotation velocity of microparticles trapped in the focus. [ABSTRACT FROM AUTHOR]

Using the Richards–Wolf formalism, we obtain explicit analytical expressions for the optical helicity density at the tight focus of four different light beams: a linearly polarized optical vortex, an optical vortex with right-handed circular polarization, superposition of a cylindrical vector beam and a linearly polarized beam, and a beam with hybrid circular-azimuthal polarization. We show that, in all four cases, the helicity density at the focus is nonzero and has different signs in different focal plane areas. If the helicity density changes sign, then the full helicity of the beam (averaged over the beam cross section at the focus) is zero and is conserved upon propagation. We reveal that the full helicity is zero when the full longitudinal component of the spin angular momentum is zero. If the helicity density does not change sign at the focus, such as in a circularly polarized optical vortex, then it is equal to the intensity in the focus, with the full helicity being equal to the beam power and conserving upon propagation. Although the helicity is related to the polarization state distribution across the beam at the focus, the expressions for the helicity density are found to be different from those for the longitudinal component of the spin angular momentum for the beams of interest. [ABSTRACT FROM AUTHOR]

In the 5th-generation mobile communication system (5G), a multiuser multiplexing scheme, nonorthogonal multiple access (NOMA), has been proposed to accommodate the massive connectivity in wireless communication systems. By nonorthogonality, NOMA allows the use of a new domain that is ineffectively utilized in conventional orthogonal multiple access (OMA) schemes. In power-domain NOMA (PD-N0MA), user signals are allocated different power levels and multiplexed by superposition coding at a transmitter. NOMA employs interference cancellation schemes such as successive interference cancellation (SIC) at receivers to avoid interference between the signals. The use of nonlinear systems such as low-resolution analog-to-digital converters (ADCs) is favorable in terms of energy consumption since the load of SIC processes increases proportionally to the number of users. However, on the other hand, the use of nonlinear systems leads to the degradation of signal detection performance. Stochastic resonance (SR) is a nonlinear phenomenon that improves the response of nonlinear systems to weak power signals. In this paper, we propose the application of SR to the nonlinear system in SIC. Through computer simulations, we show that the proposed method can improve the signal detection performance without losing the advantage of low energy consumption. [ABSTRACT FROM AUTHOR]

We address routing of classical and quantum information over quantum network and show how to exploit chirality (directionality) to achieve nearly optimal and robust transport. In particular, we prove how continuous-time chiral quantum walks over a minimal graph are able to model directional transfer of information over a network. At first, we show how classical information, encoded onto an excitation localized at one vertex of a simple graph, may be sent to any other chosen location with nearly unit fidelity by tuning a single phase. Then, we prove that high-fidelity transport is also possible for coherent superpositions of states, i.e., for routing of quantum information. Furthermore, we show that by tuning the phase parameter, one obtains universal quantum routing, i.e., independent on the input state. In our scheme, chirality is governed by a single phase, and the routing probability is robust against fluctuations of this parameter. Finally, we address characterization of quantum routers and show how to exploit the self-energies of the graph to achieve high precision in estimating the phase parameter. [ABSTRACT FROM AUTHOR]

Ray tracing is a commonly used method for modeling the propagation of electromagnetic waves in Earth's magnetosphere. To apply ray tracing results to global models of wave‐particle interaction such as energetic electron scattering, it is useful to map the discrete rays to a volume filling mesh. However, some methods have inherent losses of energy from the wave source, or do not account for the full range of wave properties within a sample volume. We have developed and tested a 3D magnetospheric ray tracing code "MESHRAY" which resolves these issues. MESHRAY uses the conservation of Poynting flux through ray triplets with finite volume to determine the local field amplitudes. Electromagnetic wave energy density from all ray data points is mapped to a mesh and verified against the wave source power for energy conservation varying time step length, number of rays, and total time steps. We find that the method is self‐consistent and numerically robust. We further investigate whether the neglect of phase information and superposition has a significant impact on the accuracy of mapping wave intensity to a mesh. We find excellent agreement between the analytic solution for waves emitted by a line source in a plane‐stratified medium and an equivalent ray tracing solution. When phase information is excluded, ray tracing reproduces an average amplitude spread over regions of coherent constructive and destructive interference. This may be an important consideration for interpolating ray tracing results of longer wavelength waves such as magnetosonic, electromagnetic ion cyclotron, or ULF waves. Key Points: Ray tracing amplitude calculations using finite‐volume ray triplets and methods using discrete, constant‐power rays are self‐consistentIntegrating electric and magnetic field wave energy density onto a space‐filling mesh is energy conserving for sufficiently small time stepsSpatially averaged amplitudes are consistent with superposed waves for regions larger than the scale of interference pattern structure [ABSTRACT FROM AUTHOR]

Vortex electromagnetic wave carrying orbital angular momentum (OAM) is expected to break through the shortage of spectrum resource because of its multiple independent modes. Nowadays, there are various methods to generate OAM vortex beam. Based on the concepts of digital metasurface and propagation phase, a broadband 3‐bit coding transmission metasurface is designed and illustrated by simulation and measurement. The elements exhibit the different phase by changing the size of metal patch, and the focusing phase is introduced to reduce the divergence of OAM beams. Based on the principle of phase superposition, the wide‐band, high‐purity, and multi‐beam OAM vortex waves can be generated by the transmission‐coding metasurface (TCMS). The experimental results verify that TCMS realizes the multiple OAM beams along different directions simultaneously from 9 to 10.5 GHz, which are consistent with the theoretical results. The high purity more than 90% of OAM mode is demonstrated by both the simulated and measured results. The TCMS provides a potential and effective scheme for OAM multiplexing and multi‐target positioning in wireless systems. [ABSTRACT FROM AUTHOR]

The article is devoted to the mathematical modeling approach of seismo-acoustic monitoring of objects and structures of sizes whose own frequencies and emission signals are from seismic and the bottom part of acoustic ranges. The structural analysis and identification of dynamic parameters of such structures are extremely important in their monitoring to predict essential changes in dynamic characteristics. Moreover, the method of dynamic identification provides an opportunity to investigate the dynamic behavior of the given structure or source of signal origin by researching investigated objects' to study informative characteristics. The article enters methodology for identifying the main structural parameters, such as main intrinsic frequencies, and the decrement in these frequencies. Particular interest represents seismo-acoustic monitoring of objects with sources of emission signals whose parameters are subject to definition and are characteristic of structure or signal origin. Emissions can carry both irregular and regular character. The latter case can be modeled as a flow with the likelihood characteristics and subject definitions. The result of the analysis of the data received in seismo-acustic monitoring of such signals is reduced to an estimation of parameters of an emission signal, which fluctuates from a signal to a signal. A practical method for analyzing natural and man-made objects, whose natural frequencies lie in the seismic and lower part of the acoustic frequency ranges, based on monitoring their dynamics, is proposed. A new approach is proposed for identifying the state of such objects. A non-traditional model of the natural background of the monitored object is proposed in the form of a superposition of Berlage impulses. Such a model makes it possible to estimate such an essential parameter in the description of an object as its quality factor, the dynamics of which can give an idea of its structural changes. To predict the behavior of natural and engineering objects to prevent undesirable consequences of the behavior of the object under study, seismo-acoustic monitoring systems are used. The mathematical model and algorithm proposed by the authors can be integrated into the system of seismo-acoustic monitoring of natural and man-made objects. [ABSTRACT FROM AUTHOR]

For humans, control of upright standing posture is a prerequisite for many physical activities. Experimentally, this control is often challenged by the motion of the support surface presented as tilt or translation, or some combination thereof. In particular, we have investigated subjects balancing in situations where tilt and translation stimuli were presented in isolation and compared it to a situation where such stimuli occurred simultaneously. Is the human posture control system in the case of two or more superimposed external disturbances responding to these as if it were dealing with one disturbance? Or does it identify the disturbances individually and as such and respond to them specifically, as suggested in a current concept of disturbance-specific estimations and compensations? We had healthy human subjects controlling their balancing of upright stance on a motion platform while we presented them with different combinations of pseudorandom support surface tilt and translation stimuli alone or in superposition (with peak-to-peak amplitude of 0.5° and 1° for tilt, and 0.8 cm and 1.5 cm for translation). In one set of trials they kept their eyes closed and in a second set open. Furthermore, a simulation was performed to qualitatively evaluate the impact of sensory non-linearities and joint stiffness modulation. We found that the experimental conditions 'eyes open' vs. 'eyes closed' always created significant differences (p < 0.05) between the frequency response functions. In contrast to this, with different combinations of the tilt and translation stimuli, significant differences between the responses were observed only in 5 cases over the 24 that have been tested. Significance The superposition of translation and tilt can be used to characterize the responses to both stimuli with one trial. When the amplitude of the stimuli is unbalanced (e.g. very small tilt superimposed with a larger translation) the effect of stiffness modulation can be studied. • Upright stance tested with a superposition of support surface tilt and translation. • Steady state response is characterized by frequency response function. • Interaction between two stimuli absent in most of the cases. • Larger stimuli may create interaction. • Simulations suggest that the observed effects can be due to joint stiffness modulation. [ABSTRACT FROM AUTHOR]

Zero voltage switching (ZVS) control is an effective and promising way to further improve the power density, efficiency and electromagnetic interference for the two paralleled silicon carbide inverters with coupled inductors. In this article, focusing on the popular 180o interleaved pulsewidth modulation (PWM), the circulating current ripple prediction model is first derived as a function of operating conditions in the time-domain. With the assistance of this model, the actual trajectory of phase-leg currents can be reconstructed by superposition of sampling fundamental current and predicted circulating current ripple, without adding any high-frequency current sensor or auxiliary circuit. By carefully considering the ZVS requirement of all switches, a variable switching frequency PWM (VSFPWM) for full range ZVS control is proposed in this article. The proposed VSFPWM shows a good performance of ZVS realization in various load situations, as well as a good dynamic response of the inverter during current step change. In addition, due to the real-time variation of switching frequency, the proposed VSFPWM demonstrates the obvious advantage in conductive EMI reduction. Both the simulation and experimental results are presented to verify the effectiveness of the analysis and proposed method. [ABSTRACT FROM AUTHOR]

The sound intensity scaling method can be used to calculate the source sound power from the array beamforming results. The distance between the sound source and the array and the environmental noise during the test process will affect the accuracy of the sound source intensity measurement. A sound power level solution method for sound intensity scaling suitable for complex environments is verified in this paper. The depth of the sound source is determined by dual arrays. The sound wave propagation and superposition characteristics are used to establish an optimized objective function, to optimize the strength of the target sound source and remove the noise components. Finally, the sound power level of the sound sources after noise reductions are calculated by the sound intensity scaling method. In the semi-anechoic room, white noise signal and impact signal are used as interference noise in the experiments. The results show that this method can effectively reduce the noise of the signal in the noisy environment and improve the calculation accuracy of the sound power level of the sound source. The error of the sound power level calculation results under the influence of white noise and impact noise has been greatly reduced after optimization. The calculation error of sound power level decreased from 3.2 dB-12.2 dB to 0.2 dB-5 dB. [ABSTRACT FROM AUTHOR]

One of the quantum theory concepts on which quantum information processing stands is superposition. Here we provide experimental evidence for the existence of classical analogues to the coherent superposition of energy states, which is made possible by the Hertz-type nonlinearity of the granules together with the external driving field. The granules' nonlinear vibrations are projected into the linear modes of vibration, which depend on one another through the phase and form a coherent superposition. We show that the amplitudes of the coherent states form the components of a state vector that spans a two-dimensional Hilbert space, and time enables the system to span its Hilbert space parametrically. Thus, the superposition of states can be exploited in two-state quantum-like computations without decoherence and wave function collapse. Finally, we demonstrate the experimental realization of applying a reversible Hadamard gate to a pure base state that brings the state into a superposition. [ABSTRACT FROM AUTHOR]

Vortex beams with orbital angular momentum (OAM) have infinite mode orthogonality, which can greatly boost communication capacity through mode-division multiplexing. However, current exploration of OAM beam transmission primarily focuses on free-space or specialty fibers limited by the OAM spiral phase wavefront characteristics. Due to the mode field phase sensitivity, these methods are constrained by turbulence interference and fabrication error tolerance, restricting transmission distance of OAM beam at practical application. Herein, we propose an OAM transmission scheme using commercial multimode fiber (MMF) exploiting the eigenmodes superposition theory. Leveraging linear superposition of HE and EH vector modes with ± (π/2) phase shift over MMF, OAM excitation and transmission can be supported with low interference. Simultaneously, due to the decreased demand for fabrication precision in the gradient core structure, the tolerance for machining errors is enhanced. As a proof-of-concept, we have demonstrated a multidimensional OAM multiplexing communication with 640-channel (4 OAM modes, 80 wavelengths and 2 polarization states) over a 5 km MMF, successfully transmitting QPSK-OFDM signals at a total rate of 15 Tbit/s. The system demonstrated OAM mode purity exceeding 65% and bit error rate (BER) below the forward error correction (FEC) threshold (3.8 × 10−3). Multiplexed OAM signals can be effectively transmitted in MMF over short to medium distances with acceptable mode crosstalk, while remaining compatible with wavelength and polarization dimensions, enabling the construction of multi-dimensional multiplexing local area networks. • Exploiting the eigenmodes superposition theory, an OAM transmission scheme using commercial multimode fiber was proposed. • A 640-channel multi-dimensional OAM multiplexing system is constructed over 5-km MMF. • 15 Tbit/s QPSK-OFDM signals are successfully transmitted withBERs below the FEC threshold and pattern purity above 65%. • The BERs are reduced by about 2 orders of magnitude after LDPC encoding for channel equalization. [ABSTRACT FROM AUTHOR]

We theoretically investigate the optical force exerted on an isotropic particle illuminated by a superposition of plane waves. We derive explicit analytical expressions for the exerted force up to quadrupolar polarizabilities. Based on these analytical expressions, we demonstrate that an illumination consisting of two tilted plane waves can provide a full control on the optical force. In particular, optical pulling, pushing, and lateral forces can be obtained by the proper tuning of illumination parameters. Our findings might unlock multiple applications based on a deterministic control of the spatial motion of small particles. [ABSTRACT FROM AUTHOR]

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the context of power quality problems, the voltage imbalance index is relevant, given its harmful impacts on the networks and loads. Thus, reliable and viable methodologies for practical use are necessary to determine agents' contributions. This article presents a noninvasive method for sharing responsibility for imbalances based on the principle of superposing the individual voltage imbalance produced by the parties. A procedure based on the Complex Independent Component Analysis (CICA) technique is proposed to meet the parameters required by the superposition method. Based on the measurements of voltages and currents carried out on the point of common coupling (PCC), the negative sequence impedances are determined using the CICA method under the terms needed by the superposition principle. The methodology's effectiveness is evaluated through performance comparisons carried out over the process, in light of the response from the methods for sharing responsibilities currently published in the literature of this domain. The results obtained through the proposed approach show good adherence to the procedures presented with solid conceptual bases. However, unlike these, this article's methodology offers practical perspectives for application in the field. [ABSTRACT FROM AUTHOR]

Quantum computation based on a gate model is described. This model initially creates a superposition | ψ 0 〉 consisting of N = 2 n states, and these states are labeled by an n qubit index value j. Two working qubits | 0 〉 w k 0 and | 0 〉 w k 1 are added for a measurement. Moreover, one marking qubit | 0 〉 m k is added to discriminate between states in a superposition. Thus, | ψ 1 〉 = 1 / N ∑ j = 0 N − 1 | j 〉 ⊗ | 0 〉 w k 0 ⊗ | 0 〉 w k 1 ⊗ | 0 〉 m k . The Hadamard transformation is applied to | 0 〉 w k 0 and | 0 〉 w k 1 . | ψ 2 〉 = 1 / N 1 / 2 2 ∑ j = 0 N − 1 | j 〉 ⊗ | 0 〉 w k 0 + | 1 〉 w k 0 ⊗ | 0 〉 w k 1 + | 1 〉 w k 1 ⊗ | 0 〉 m k . After a computation, a set of states is divided into two subsets; one is a subset bad (B) and the other is a subset good (G). | ψ 3 〉 = 1 / N 1 / 2 2 ∑ j ∈ B | j 〉 ⊗ | 0 〉 w k 0 + | 1 〉 w k 0 ⊗ | 0 〉 w k 1 + | 1 〉 w k 1 ⊗ | 0 〉 m k + ∑ j ∈ G | j 〉 ⊗ | 0 〉 w k 0 + | 1 〉 w k 0 ⊗ | 0 〉 w k 1 + | 1 〉 w k 1 ⊗ | 1 〉 m k . After a marking, a superposition is measured by POVM. The measurement is described by a collection of four measurement operators. The measurement transforms | ψ 3 〉 into | ψ 4 〉 = 1 / N ∑ j ∈ B | j 〉 ⊗ | 0 〉 w k 0 ⊗ | 0 〉 w k 1 ⊗ p 0 sin θ | 0 〉 m k + ∑ j ∈ G | j 〉 ⊗ | 0 〉 w k 0 ⊗ | 0 〉 w k 1 ⊗ p 1 cos θ | 1 〉 m k / D ; here, D = card B p 0 ∗ p 0 sin 2 θ + card G p 1 ∗ p 1 cos 2 θ , and p 0 ∗ p 0 sin 2 θ + p 1 ∗ p 1 cos 2 θ = 2 which is derived from the completeness equation. The state | 0 〉 m k and the state | 1 〉 m k before the measurement are transformed into p 0 sin θ | 0 〉 m k and p 1 cos θ | 1 〉 m k , respectively. This paper describes these measurement operators. [ABSTRACT FROM AUTHOR]

The superposition of orbital angular momentum (OAM) in a surface plasmon polariton (SPP) field has attracted much attention in recent years for its potential applications in classical physics problems and quantum communications. The flexible adjustment of the amplitudes of two OAM states can provide more freedom for the manipulation of superposed states. Here, we propose a type of plasmonic metasurface consisting of segmented spiral-shaped nanoslits that not only can generate the superposition of two OAM states with arbitrary topological charges (TCs), but also can independently modulate their relative amplitudes in a flexible manner. The TCs of two OAM states can be simultaneously modulated by incident light, the rotation rate of the nanoslits, and the geometric parameters of the segmented spiral. The relative amplitudes of the two OAM states are freely controllable by meticulously tuning the width of the nanoslits. Under a circularly polarized beam illumination, two OAM states of opposite TCs can be superposed with various weightings. Furthermore, hybrid superposition with different TCs is also demonstrated. The presented design scheme offers an opportunity to develop practical plasmonic devices and on-chip applications. [ABSTRACT FROM AUTHOR]

Light absorption by molecular exciton states in disordered networks is studied. The main purpose of this paper is to look at how phases of the intermediate ground–excited state superposition interfere during the absorption process. How does this phase average enable, or suppress, absorption to a delocalized state? To address this question, a theory for phase oscillators is used to predict the purity of the collective excited state of the network. The results of the study suggest that collective absorption by molecular exciton states requires a sufficiently large electronic coupling between molecules in the network compared to the random distribution of transition energies at the sites, even when the molecular network is completely isolated from the environment degrees of freedom. The 'dividing line' between absorption to a mixture of, essentially, localized excited states and coherent excitation of a pure delocalized exciton state is suggested to be predicted by the threshold of phase synchronization. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we focused on the effect of the underwater explosion parameters of multi-point array explosion. The shock wave and bubble parameters of aggregate charge, two charges, and four charges were measured through an underwater explosion test, and their influence on the explosion power field of charge quantity and array distance was analyzed. Results show that the multi-shock wave collision of array explosion can be approximated to a linear superposition, and the interaction of delayed shock wave can be deemed as the increase of the shock wave baseline. Shock wave focusing and delayed superposition increase the shock wave peak pressure. Compared with the aggregate charge, the greater the number of array explosion points is, the higher the impulse and the gain of the bubble peak pressure are. At the same array distance, the smaller the charge quantity is, the higher the bubble impulse will be. At the same charge quantity, the smaller the array distance is, the higher the bubble impulse will be. The bubble period decreases gradually with the increase of the charge quantity, but the test orientation has little effect on the bubble period. [ABSTRACT FROM AUTHOR]

Queueing systems with batch Markovian arrival process (BMAP) have paramount applications in the domain of wireless communication. The BMAP has been used to model the superposition of video sources and to approximate the super-position of data, voice and video traffic. This article analyzes an infinite-buffer generally distributed batch-service queue with BMAP, general bulk service (a, b) rule and batch-size-dependent service time. In this proposed analysis, we mainly focus on deriving the bivariate vector generating function of queue and server content distribution together at departure epoch using supplementary variable technique. The mathematical procedure for the complete extraction of distribution at departure epoch has been discussed and using those extracted probabilities, we achieve the queue and server content distribution at arbitrary epoch. Finally, numerical illustrations have been carried out in order to make a deep insight to the readers which contains deterministic as well as phase-type service time distributions. [ABSTRACT FROM AUTHOR]

Copyright of Geography & Geographic Information Science is the property of Geography & Geo-Information Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, vibration prediction of space large-scale membranes from the energy point of view is investigated. Based on the Green kernel of vibrating membranes, a new analytical representation of energy response of infinite membranes is derived. Averaged energy is used as the main variable so that the response fluctuation can be smoothed. Then membranes of various shapes can be taken into account by introducing the mean free path into the formulation to describe travel distances of energy waves. The energy response of finite membranes is obtained with the superposition of energy waves subsequently. Considering uncertainties usually becomes significant in large-scale structures, the formulation expressed with random variables is obtained for membranes with uncertain properties. The mathematical expectation and variance of energy response are derived subsequently. And the confidence interval of random response is obtained. Finally, numerical simulations are performed to validate the proposed formulations and characteristics of the random energy responses are analyzed by taking a space large-scale membrane structure as a model. The developed formulations make the analysis of membranes with uncertainties more convenient than Finite Element Method (FEM) since they are expressed in analytical forms. Compared with existing formulations of energy flow derived from deterministic travel distances of waves that only apply to regular shapes of structures, the proposed formulations are suitable for membranes of various shapes. This work provides an alternative analytical approach to vibration prediction for space large-scale membranes with uncertainties. And the approach is thought helpful for the vibration analysis of other two-dimensional structures. [ABSTRACT FROM AUTHOR]

Papers I and II in this series [R. M. Richard et al., J. Chem. Phys. 141, 014108 (2014); K. U. Lao et al., ibid. 144, 164105 (2016)] have attempted to shed light on precision and accuracy issues affecting the many-body expansion (MBE), which only manifest in larger systems and thus have received scant attention in the literature. Many-body counterpoise (CP) corrections are shown to accelerate convergence of the MBE, which otherwise suffers from a mismatch between how basis-set superposition error affects subsystem versus supersystem calculations. In water clusters ranging in size up to (H2O)37, four-body terms prove necessary to achieve accurate results for both total interaction energies and relative isomer energies, but the sheer number of tetramers makes the use of cutoff schemes essential. To predict relative energies of (H2O)20 isomers, two approximations based on a lower level of theory are introduced and an ONIOM-type procedure is found to be very well converged with respect to the appropriate MBE benchmark, namely, a CP-corrected supersystem calculation at the same level of theory. Results using an energy-based cutoff scheme suggest that if reasonable approximations to the subsystem energies are available (based on classical multipoles, say), then the number of requisite subsystem calculations can be reduced even more dramatically than when distance-based thresholds are employed. The end result is several accurate four-body methods that do not require charge embedding, and which are stable in large basis sets such as aug-cc-pVTZ that have sometimes proven problematic for fragment-based quantum chemistry methods. Even with aggressive thresholding, however, the four-body approach at the self-consistent field level still requires roughly ten times more processors to outmatch the performance of the corresponding supersystem calculation, in test cases involving 1500-1800 basis functions. [ABSTRACT FROM AUTHOR]

The shear thinning of a lubricant significantly affects lubrication film generation at high shear rates. The critical shear rate, defined at the onset of shear thinning, marks the transition of lubricant behaviors. It is challenging to capture the entire shear-thinning curve by means of molecular dynamics (MD) simulations owing to the low signal-to-noise ratio or long calculation time at comparatively low shear rates (104-106 s-1), which is likely coincident with the shear rates of interest for lubrication applications. This paper proposes an approach that correlates the shear-thinning phenomenon with the change in the molecular conformation characterized by the radius of gyration of the molecule. Such a correlation should be feasible to capture the major mechanism of shear thinning for smallto moderate-sized non-spherical molecules, which is shear-induced molecular alignment. The idea is demonstrated by analyzing the critical shear rate for squalane (C30H62) and 1-decene trimer (C30H62); it is then implemented to study the behaviors of different molecular weight poly-α-olefin (PAO) structures. Time-temperature-pressure superpositioning (TTPS) is demonstrated and it helps further extend the ranges of the temperature and pressure for shear-thinning behavior analyses. The research leads to a relationship between molecular weight and critical shear rate for PAO structures, and the results are compared with those from the Einstein-Debye equation. [ABSTRACT FROM AUTHOR]

Predicting the future trajectories of traffic agents is a pivotal aspect in achieving collision-free driving for autonomous vehicles. Although the overall accuracy of existing prediction methods appears promising, most of them overlook the long-tailed challenge in trajectory prediction. They tend to excuse or overlook the disastrous performance in rare yet safety-critical tail events. This paper puts forward a novel framework called hierarchical wave-semantic contrastive learning (Hi-SCL), which attempts to fight the long-tailed challenge in the trajectory prediction task. Our approach innovatively represents each traffic scene as "waves", and implicitly models traffic multi-stream interactions through wave superposition at both local and global levels. This pioneering incorporation of the wave concept enhances the in-depth comprehension of the traffic scene. On this basis, we introduce the feature hierarchical reshaping method, empowering our network to cope with formidable infrequent cases effectively. This module maintains a collection of feature-enhanced hierarchical prototypes, dynamically steering trajectory samples closer or pushing them farther away in an unsupervised learning setup. Extensive experiments on real-world datasets validate Hi-SCL's robust overall prediction performance and its effectiveness in addressing long-tailed challenges. Compared to several baseline models, Hi-SCL demonstrates remarkable improvements in general predictive accuracy, with long-term prediction error reductions ranging from 14% to 54% for minADE and 27% to 79% for minFDE. The outcomes of long-tailed experiments further underscore the capacity of Hi-SCL, offering accuracy gains ranging from 2% to 17% in tailed samples. The thorough empirical analyses confirm Hi-SCL's exceptional capability of wave-semantic representation learning and its effectiveness in reshaping the feature space via hierarchical contrastive learning mechanisms. The proposed new paradigm paves the way for substantial advancements in trajectory prediction, especially in overcoming long-tailed issues, bringing us closer to realizing safer autonomous driving systems. • A novel hierarchical wave-semantic contrastive learning framework is proposed to combat long-tailed challenges in trajectory prediction. • The wave-semantic interaction mechanism is introduced to aggregate the meticulously designed wave-semantic representations in local and global manners. • The feature hierarchical reshaping module is designed to steer trajectory samples closer or push them farther away with unsupervised learning. • Results on real-world autonomous driving datasets demonstrate the effectiveness of our method in solving long-tailed challenges. [ABSTRACT FROM AUTHOR]

Decision-makers encounter heightened challenges in analyzing risks due to the intricate nature and uncertainty inherent in complex product delivery scenarios. To address these challenges, a reliability index-based group decision-making approach is proposed. Firstly, considering the abundance of information sources complicates verifying their authenticity, a reliability index is introduced. This index combines evaluation information with the reliability index to form two-dimensional linguistic information. Secondly, recognizing the personalized nature of linguistic information poses hurdles in alternative selection, integrating personalized individual semantics into information aggregation is emphasized. To capture the authentic perspectives of decision-makers, two linguistic optimization models are developed. Thirdly, acknowledging the subconscious emotional interactions among decision-makers and the interplay of opinions among them significantly influencing final decisions, the integration of quantum probability theory is proposed to construct an expert weight optimization model. Ultimately, the effectiveness and feasibility of this method are verified within a manufacturing company, providing crucial insights into real-world complex product delivery risk mitigation strategies. The results demonstrate that our proposed model efficiently integrates two kinds of linguistic information from participants based on personalized cognitions and selects the optimal alternative based on dual belief superposition. This article proposes the first GDM method for analyzing risk factors in complex product delivery, emphasizing personalized cognition and dual belief superposition, which are important factors previously rarely accounted for. • A reliability index is proposed to measure information source reliability. • Two-dimensional linguistic information is used to optimize decision-making. • Two optimization models are set to solve personalized cognitive deviation. • Dual belief superposition is studied to mitigate decision result impact. • A real-world issue for complex product delivery is applied to show the feasibility. [ABSTRACT FROM AUTHOR]

Aiming at the serious deformation and failure of mining roadway under the condition of high secondary stress in Xuchang Coal Mine, Shandong Province, the deformation law of surrounding rock under the influence of high secondary stress in the original support belt transport roadway was analyzed by the method of field measurement and numerical simulation, and the control scheme of surrounding rock was put forward. According to the actual site conditions of 3318 working face belt transport drift in Xuchang Coal Mine, this paper proposed a new bolt-net support technology scheme with high strength, high stiffness, and asymmetric characteristics and obtained through numerical simulation analysis: (1) when the 3318 working face begins to mining, the distribution of the maximum principal stress in the surrounding rock of the roadway changes from weak symmetry to strong asymmetry, especially the maximum principal stress in the surrounding rock of the two sides; (2) the superposition effect of leading abutment pressure, lateral abutment pressure, and fault structure has a strong influence on the distribution of the maximum principal stress of roadway surrounding rock. The field industrial test shows that the deformation of the surrounding rock at different parts of the belt transport roadway is significantly reduced after the implementation of the double-height asymmetric bolting support. Among them, the deformation of the roof decreases from 630 mm to 185 mm, the deformation of the left wall decreases from 550~620 mm to 150~170 mm, and the deformation of the right wall decreases from 600 mm to less than 180 mm. The nonuniform deformation degree of the top side is within 1~1.13, indicating that the anchor mesh composite bearing structure is uniformly deformed as a whole, and the overall bearing capacity of the structure is realized. [ABSTRACT FROM AUTHOR]

We study the connection between the phase and the amplitude of the wave function and the conditions under which this relationship exists. For this we use the model of particle in a box. We have shown that the amplitude can be calculated from the phase and vice versa if the log analytical uncertainty relations are satisfied. [ABSTRACT FROM AUTHOR]

Gravity curves space and time. This can lead to proper time differences between freely falling, nonlocal trajectories. A spatial superposition of a massive particle is predicted to be sensitive to this effect. We measure the gravitational phase shift induced in a matter-wave interferometer by a kilogram-scale source mass close to one of the wave packets. Deflections of each interferometer arm due to the source mass are independently measured. The phase shift deviates from the deflection-induced phase contribution, as predicted by quantum mechanics. In addition, the observed scaling of the phase shift is consistent with Heisenberg’s error-disturbance relation. These results show that gravity creates Aharonov-Bohm phase shifts analogous to those produced by electromagnetic interactions. [ABSTRACT FROM AUTHOR]

Synthetic aperture radar (SAR) human-imaging technology has been widely used in the fields of security screening and activity recognition. However, most of the existing methods aim at stationary human targets, resulting in severe restrictions on their potential applications. In this article, an SAR imaging method for walking human is proposed with short aperture terahertz (THz) radar. This method is based on a modified wavenumber domain approximate algorithm ($\text{m}{\omega }$ ka), whose interpolation mapping is modified according to the approximation of region of interest (RoI). Because the nonrigid motion phase error caused by the walking human would lead to severe deformation and blur in imaging results, a compensation processing is essential. To figure it out, the fractional Fourier transform combined with the maximum and minimum generalized likelihood ratio test (FrFT-mmGLRT) is devised in this article. Within a short aperture time, the nonrigid motion of walking human can be approximately assumed as a superposition of the rigid movements of different human body parts. Particularly, by taking advantage of the superposition property of FrFT, the motion phase errors of different human body parts are distinguished and estimated by jointly searching for the peaks of FrFT energy spectrum. Furthermore, the mmGLRT-based composite imaging technique is utilized to obtain a whole body result from the compensated results of different body parts. Finally, numerical simulation and real experiments are conducted to verify the feasibility and capability of the proposed method for walking human SAR imaging. [ABSTRACT FROM AUTHOR]