Inverse Methods - Science topic

The response of the Antarctic ice sheet to climate change and its contribution to sea level under different emission scenarios are subject to large uncertainties. A key uncertainty is the slipperiness at the ice sheet base and how it is parameterized in glaciological projections. Alternative formulations of the sliding law exist, but very limited a...

This study presents a general formulation of topology optimization for nonlinear materials, in which the evolutions of internal variables describe material responses. To ensure generality, the formulation of the primal problem covers arbitrary nonlinear behavior realized by internal variables. The governing equations of the primal problem are deriv...

We compare three model-free numerical methods for inverting structural data to obtain interaction potentials, namely iterative Boltzmann inversion (IBI), test-particle insertion (TPI), and a machine-learning (ML) approach called ActiveNet. Three archetypal models of two-dimensional colloidal systems are used as test cases: Weeks--Chandler--Anderson...

We propose a novel approach that combines regional ocean data prediction with typhoon trajectory inversion methods to improve the forecasting of typhoon trajectories. This model expands outward from the current path to create a grid within a fixed range of latitudes and longitudes, populated with future ocean environment information to effectively...

An efficient and stable Abel inversion method is developed using Zernike polynomials to reconstruct the local emissivity profile from line integrated data. We reconstructed emissivity for parabolic, Gaussian, and non-monotonic profiles. By leveraging Cormack’s method, we skip evaluating the integrals numerically, reducing error in reconstruction. T...

We present a comprehensive reappraisal of the in-medium properties of the rho meson using the inverse QCD sum rules (QCDSR) formalism, offering a novel, model-independent approach to studying hadronic modifications in nuclear matter. Unlike conventional QCDSR, which rely on a predefined pole+continuum structure, the inverse method reconstructs the...

Three-dimensional (3-D) magnetic inversion is an essential technique for revealing the distribution of subsurface magnetization structures. Conventional methods are often time-consuming and suffer from ambiguity due to limited observations and non-uniqueness. To address these limitations, we propose a novel inversion method under the machine learni...

This paper presents a comprehensive integration of Stochastic Inversion Theory with reinforcement learning techniques inspired by the dopaminergic system of the biological brain, as studied in modern neurosciences. The first part of the paper recalls the basic concepts of stochastic inversion, outlining its application to geophysical data inversion...

In this study, we address the question of whether we can properly determine differential emission measures (DEMs) using Solar Orbiter/Extreme Ultraviolet Imager (EUI)/Full Sun Imager (FSI) and AI-generated extreme UV (EUV) data. The FSI observes only two full-disk EUV channels (174 and 304 Å), which is insufficient for accurately determining DEMs a...

To acquire Johnson–Cook (J-C) constitutive parameters that accurately depict the mechanical behavior of powder liner under conditions of high pressure, elevated temperature, and large deformation, as well as Holmquist–Johnson–Cook (HJC) constitutive parameters that precisely describe the dynamic damage of hard rock and make them suitable for numeri...

Polyethersulphone (PES) composite membrane was prepared by green synthesized cobalt oxide (Co3O4) powders using the phase inversion method. Both Co3O4 powders and prepared composite membranes were characterized by using Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) and X-Ray Diffraction (XRD) techniques. Three diffe...

HFC-134a is the most prevalent hydrofluorocarbon used as a replacement for ozone-depleting CFCs and HCFCs. Due to its high global warming potential, it is regulated under various European and global frameworks, underscoring the importance of tracking its emissions. Emissions derived by the commonly used, bottom-up, methodology are affected by a cer...

The Community Inversion Framework (CIF) brings together methods for estimating greenhouse gas fluxes from atmospheric observations. While the analytical and variational optimization methods implemented in CIF are operational and have proved to be accurate and efficient, the initial ensemble method was found to be incomplete and could hardly be comp...

Due to the scarcity of in situ measurements in the thermosphere, the retrieval of thermospheric mass density primarily relies on model simulations or the inversion of satellite accelerometers and orbital data. Density derived from satellite inversion is more accurate, often reflecting the actual density at the satellite altitude. However, due to th...

Geometric Asian options are a type of option where the payoff depends on the geometric mean of the underlying asset over a certain period of time. This paper is concerned with the pricing of such options for the class of Volterra-Heston models, covering the rough Heston model. We are able to derive semi-closed formulas for the prices of geometric A...

Debris flows are fast‐flowing, high‐energy mixtures of sediment and water that are difficult to monitor. Seismic monitoring instruments can be placed safely outside the channel, but it is an indirect method that needs the application of theory‐based inversion to obtain quantitative information on flow properties and rheology. Such inversion methods...

Gold ores are important strategic key mineral resource in China. The Sanshan Island area produces gold ores, in which the magmatic activity becomes the heat source for the activation of gold-bearing fluids, and the widely developed fracture structure provides the channel and spatial structure for gold transport and enrichment. Therefore, it is an i...

This paper presents a robust and efficient velocity inversion method based on multi-round iterative deep learning in the sparse transform domain. Current deep learning approaches for velocity model building face challenges in prediction accuracy and generalization due to dependence on large-scale, diverse training datasets. To address this, the pro...

Frequency transfer is a key challenge in machine learning as it allows researchers to go beyond in-range analyses of spectrum properties towards out-of-the-range predictions. Traditionally, to predict properties at a specific frequency, targeted spectrum is included in training data for a deep neural network (DNN). However, due to limitations of me...

White Gaussian noise (WGN) is widely used in communication system testing, physical modeling, Monte Carlo simulations, and electronic countermeasures. WGN generation relies heavily on random numbers. In this work, we present an implementation of WGN generation utilizing a quantum entropy source chip for the first time. A photonic integrated chip ba...

Rock alteration leads to the degradation of the physical and mechanical properties of original rock. The spatial variance in the degree of rock alteration significantly influences regional ground stress distribution characteristics. The key problem in the process of ground stress inversion of 3-d geological model of underground powerhouse is that t...

The high-magnetic anomaly belt in the northern slope of the South China Sea has long been associated with a Mesozoic volcanic arc. However, its crustal architecture remains unclear, limiting the understanding of its geological implications. We assembled high-resolution reduced-to-the-pole aeromagnetic anomaly data around the northern South China Se...

In response to the issue that existing soil moisture monitoring methods are significantly affected by surface roughness and the complex environment around water bodies, leading to a need for improvement in the accuracy of soil moisture inversion, a soil moisture detection algorithm based on a DCU-Net (Deformable Conv Unit-Net) water body extraction...

Objective Quantitative susceptibility mapping (QSM) is a technique that has been demonstrated to be highly repeatable in the brain. As QSM is applied to other parts of the body, it is necessary to investigate metrics for quantifying repeatability, to enable optimization of repeatable QSM reconstruction pipelines beyond the brain. Materials and met...

PVDF, PVDF/PVP and PVDF/PVP/CNC membranes were prepared using the phase inversion method using polyvinylidene fluoride (PVDF), polyvinylpyrrolidone (PVP) and cellulose nanocrystal (CNC). The morphologies of the membranes and CNC were determined by scanning electron microscopy (SEM), and the mechanical properties of the membranes were determined by...

I will demonstrate the effectiveness of Physics-Informed Neural Networks (PINNs) in solving partial differential equations (PDEs) when training data are scarce or noisy. The training data can be located either at the boundaries or within the domain. Additionally, PINNs can be used as an inverse method to determine unknown coefficients in the equati...

Buried hill reservoirs are characterized by complex formation conditions and highly heterogeneous rock structures, which result in the poor performance of traditional crossplot methods in stratigraphic lithology classification. Logging curves, as comprehensive reflections of various petrophysical properties, are influenced by complex geological fac...

Least-squares reverse time migration (LSRTM) is an advanced seismic imaging technique that reconstructs subsurface models by minimizing the residuals between simulated and observed data. Mathematically, the LSRTM inversion of the sub-surface reflectivity is a large-scale, highly ill-posed sparse inverse problem, where conventional inversion methods...

Text-to-image diffusion models offer powerful image editing capabilities. To edit real images, many methods rely on the inversion of the image into Gaussian noise. A common approach to invert an image is to gradually add noise to the image, where the noise is determined by reversing the sampling equation. This process has an inherent tradeoff betwe...

This study introduces a novel joint inversion scheme using the variable Particle Swarm Optimization-Grey Wolf Optimization (vPSOGWO) algorithm, specifically designed to improve the integration of Receiver Function (RF) and Magnetotelluric (MT) data. The proposed algorithm incorporates variable inertia and population sizes, enhancing both exploratio...

Air switchgear is an important power equipment in the transmission, transformation, and distribution process of the power system. Insulation defects can lead to partial discharge, which is one of the primary causes of air switchgear failure. Current monitoring methods primarily rely on detecting ultra-high frequency or ultrasonic signals generated...

We compare three model-free numerical methods for inverting structural data to obtain interaction potentials, namely, iterative Boltzmann inversion (IBI), test-particle insertion (TPI), and a machine-learning (ML) approach called ActiveNet. Three archetypal models of two-dimensional colloidal systems are used as test cases: Weeks–Chandler–Anderson...

The utilization of synthetic aperture radar (SAR) for depth inversion is crucial for accurate underwater mapping. However, current SAR-based techniques face challenges in segmentation accuracy, which directly affects inversion precision and spatial resolution. Traditional segmentation methods lack efficiency and often result in low-resolution outco...

Context. The relationship between an active galactic nucleus (AGN) and its host galaxy is still far from being understood. Properties of the host galaxies of Seyfert nuclei, such as luminosity concentration, morphological type, metallicity, and age of the stellar population, are expected to be related with nuclear activity – either at the epoch of...

Characterizing fractures through inversion is essential for predicting the long-term thermal performance of enhanced geothermal systems (EGSs). Previous studies often assumed a constant fracture aperture to simplify fracture inversion. However, both experimental and numerical results indicate significant variations in fracture aperture due to compl...

In Mongolia, the traditional pastoral system has changed by the overuse and degradation of water resources. However, there is a research gap between the socio-economic transition and ecosystem degradation on the existing knowledge. In the present study, a process-based eco-hydrology model, National Integrated Catchment-based Eco-hydrology (NICE), w...

Longitudinal models with dynamics governed by differential equations may require numerical integration alongside parameter estimation. We have identified a situation where the numerical integration introduces error in such a way that it becomes a novel source of non-uniqueness in estimation. We obtain two very different sets of parameters, one of w...

The identification of the traction acting on a portion of the surface of an anisotropic solid is very important in structural health monitoring and optimal design of structures. The traction can be determined using inverse methods in which displacement or strain measurements are taken at several points on the body. This paper presents an inverse me...

In this study, we assess the state of the stress field in eastern Türkiye and discuss whether the stress field in the region has changed over time. To assess the governing stress field, we applied stress tensor inversion techniques using focal mechanisms from earthquake catalogs. The focal mechanisms were grouped into subregions based on spatial an...

Overlying hard and thick igneous rocks pose numerous potential safety hazards during the exploitation of coal resources. Identifying the spatial distribution of igneous rocks and analyzing their impact on coal mining are a primary research concern. In this study, a coal mine was investigated in depth. Initially, based on the seismic information, th...

Radio occultation observation has garnered significant attention owing to its low‐cost, all‐weather, and global coverage feature. However, traditional occultation inversion methods lead to error accumulation due to assumptions that are not entirely suitable in the real ionospheric environment, resulting in poor performance in the low ionosphere (D,...

Due to its long-term and high-frequency observation capabilities, remote sensing is widely recognized as an indispensable and preferred technology for large-scale and cross-regional water quality monitoring. This paper comprehensively reviews the recent progress of remote sensing for water environment monitoring, predominantly focusing on remote se...

High-resolution water depth data are of great significance in island research and coastal ecosystem monitoring. However, the acquisition of high-resolution imagery has been a challenge due to the difficulties and high costs associated with obtaining such data. To address this issue, this study proposes a water depth inversion method based on Gaofen...

This paper presents a space-based limb-imaging spectrometer (LIS) for detecting atmospheric O2 airglow; it scans the atmosphere with a vertical range of 10–100 km and has a vertical resolution of 2 km. The LIS’s detection performance needs to be examined before launch. A forward radiative transfer model (RTM) of airglow is studied to determine the...

The relationship between an active galactic nucleus (AGN) and its host galaxy is still far from being understood. Properties of the host galaxies of Seyfert nuclei, such as luminosity concentration, morphological type, metallicity, and age of the stellar population are expected to be related with nuclear activity -- either at the epoch of galaxy fo...

Traditional mechanical methods for implant and bone cement removal during total hip arthroplasty (THA) revision surgeries typically lead to surrounding tissue damage and increased risk of femoral fractures. Transcutaneous induction heating is a promising new removal approach as it causes softening of the thermoplastic bone cement, and thus prevents...

Topological zero modes in topological insulators or superconductors are exponentially localized at the phase transition between a topologically trivial and nontrivial phase. These modes are solutions of a Jackiw-Rebbi equation modified with an additional term which is quadratic in the momentum. Moreover, localized fermionic modes can also be induce...

Context. The discovery rate of near-Earth asteroids (NEAs) has steadily increased over the past three decades, yet the physical characterization of these objects has not kept pace. Aims. In an effort to help address this gap, we combined targeted photometric observations, archival data, and sparse photometric data from the Asteroid Terrestrial-impa...

The geological structure in the Red River fault zone (RRF) and adjacent areas is complex. Due to the lack of high-precision gravity data in the study area, it is difficult to obtain the distribution of materials within the Earth’s crust. In this study, a gravity data-fused method is proposed. The Moho depth model data are utilized to construct the...

Amine solutions are widely used to remove sour components (primarily H2S and CO2) from natural gas and light hydrocarbon gases. Removal of solids from amine solutions is essential for the efficient operation of gas purification plants. In this work, flat-surface composite membranes were synthesized using a phase inversion method based on polyvinyli...

The freshwater content of the Arctic Ocean has increased dramatically in the last two decades, particularly in the Beaufort Gyre. However, quantifying the sources of this change is an observational challenge and has historically been limited by methodological differences across studies. Here we derive observation‐based freshwater budgets from volum...

This study investigated the properties of a novel polymeric membrane based on cellulose acetate, polyethylene glycol/poly(styrene)-b-poly(4-vinylpyridine), and embedded with TiO2 nanoparticles (CA/PEG/PS154-b-P4VP381/TiO2 membrane) obtained by wet-phase inversion method. The TiO2 nanoparticles fabricated by a hydrothermal method were characterized...

In trying to protect honey bee species and maintain genetic diversity, employing effective approaches for drone sperm conservation is crucial. Based on literature, drone sperm cryopreservation extenders and methods have not been fully optimized. Our research aim was to enhance drone bee sperm preservation by incorporating royal jelly (RJ) in the ex...

Processing facial images with varying poses is a significant challenge. Most existing face frontalization methods rely on heavy architectures that struggle with small datasets and produce low‐quality images. Additionally, although video frames provide richer information, these methods typically use single images due to the lack of suitable multi‐im...

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A conventional linear pre-stack inversion method under the conventional stationary convolution model is limited by the assumptions of weak formation contrast change and small angle incidence and fails to take into account the amplitude attenuation of seismic wave propagation. Meanwhile, the resolution and precision of oil and gas evaluation and fra...

This study addresses the issue of atmospheric delay correction for the rational polynomial coefficient (RPC) model associated with spaceborne synthetic aperture radar (SAR) imagery under conditions lacking ephemeris data, proposing a novel approach to enhance the geometric positioning accuracy of RPC models. A satellite position inversion method ba...

Tree roots are vital for tree ecosystems; accurate root detection helps analyze the health of trees and supports the effective management of resources such as fertilizers, water and pesticides. In this paper, a deep learning-based ground-penetrating radar (GPR) inversion method is proposed to simultaneously image the spatial distribution of permitt...

We investigate the influence of fault roughness on physical damage prior to large laboratory rock failure and the evolution of the local stress field surrounding the fault zone as macroscopic shear slip approaches. To achieve this, we analyze acoustic emission (AE) data from displacement‐driven rock friction experiments conducted on porous sandston...

Source rock characterization (SRC) is one of the important approaches in the exploration of geology. The SRC in a sedimentary basin is economically crucial in conventional and unconventional hydrocarbon resources. This investigation uses the integration of seismic data inversion methods and geochemical data to evaluate an accurate total organic car...

The ground-motion duration, the time window in which the ground motion time history is considered to be strong, may be classified into three main groups, i.e., uniform, bracketed, and significant duration. In the current study, the three definitions were employed to argue why "significant duration" is the preferred model to calculate shear wave dur...

The construction of accurate anisotropic velocity models is essential for effective microseismic monitoring in hydraulic fracturing. Ignoring anisotropy can result in significant distortions in microseismic event locations and their interpretation. Although methods exist to simultaneously invert anisotropic parameters and event locations using micr...

To systematically study the effect of oblique compressible turbulence on inverse synthetic aperture lidar (ISAL) imaging, the atmospheric random phase screen with modified compressible turbulence spectrum is numerically simulated by using FFT spectral inversion method. Using Kirchhoff approximation and convolutional inverse projection algorithm, IS...

We use the full waveform inversion method to study the crustal‐mantle seismic structure beneath Central Asia. By combining earthquake waveforms and ambient noise cross‐correlations, we construct a 3D model of Vp and Vs down to a depth of 220 km. This model reveals a complex Indian‐Asian plate configuration and interaction, resulting from the plate...

This paper proposes a probabilistic convolutional neural network-low density parity check (PCNN-LDPC) demodulation scheme for orbital angular momentum shift keying free-space optical (OAM-SK-FSO) communication systems, with a focus on its bit error rate (BER) performance. Initially, the original information sequences were encoded by a low-density p...

We present combinatorial cum group theoretical generating function methods for vertex and face colorings of a dodecahedron for all irreducible representations of the icosahedral group. We demonstrate the usefulness of the Mȍbius inversion method. We consider several types of distortions arising from the highly symmetric dodecahedron, in particular,...

Beach surface moisture (BSM) is crucial to studying coastal aeolian sand transport processes. However, traditional measurement techniques fail to accurately monitor moisture distribution with high spatiotemporal resolution. Remote sensing technologies have garnered widespread attention for providing rapid and non-contact moisture measurements, but...

We investigate the feasibility of using rocket launches, specifically rocketquakes, as a seismic source to image subsurface velocity and geology of planetary bodies. Toward this goal, we record the seismic vibrations excited by a Falcon 9 rocket launch from Vandenberg Space Force Base (SFB) near Lompoc, California. Nine passive three-component (3C)...

Gas diffusion trend tracking and concentration perception are critical challenges in chemical safety. Existing methods suffer from different limitations such as restricted sensing range, sluggish response, high costs, and weak localization. In sight of this, we endeavor on a scarcely explored task known as real-time reconstruction of gas clouds bas...

Glycerohydrogels based on silicon glycerolate, chitosan (CS) and polyvinyl alcohol (PVA) are widely studied for use in biomedical applications. In line with the general trend of replacing synthetic polymers with natural ones in such compositions, it would be of interest to replace PVA with the polysaccharide glucomannan (GM), as well as to introduc...

The evergrowing computational complexity of High Performance Computing applications is often met with an horizontal scalling of computing systems. Colaterally, each added node risks being a single point of failure to parallel programs, increasing the demand for fault tolerant techniques to be applied, specially at software level. Under such conditi...

A nonparametric generalized inversion technique for the S-wave amplitude spectrum on both the horizontal and vertical components was adopted to calculate the source parameters, site effects, and path attenuations. In this scheme, 1647 three-component records corresponding to 78 earthquakes with Ms values of 2.9–6.0 recorded by 58 strong-motion stat...

This study proposes a structurally regularized 3D magnetotelluric (MT) inversion method that enhances model consistency with independently derived guiding models by adjusting the weights of the roughness operator. Numerical tests and application to MT data from Northeast Japan show that this approach improves resistivity model accuracy and broadens...

Currently, determining the mechanical parameters by inverse analysis in deep-buried tunnels is still challenging and essential. Problems such as the limitation of unknown parameter dimensions (tremendous computational cost) and insufficient inversion accuracy may occur when using the conventional inverse method to solve the mechanical parameters of...

We present a new technique to constrain the gravitational potential of a galaxy from the observed stellar mass surface density alone under a number of assumptions. It uses the classical Eddington inversion method to compute the phase-space distribution function (DF) needed for stars to reside in a given gravitational potential. In essence, each pot...

The embedded atom method potential for the Ni–Al–Co–Ti–Cr quinary alloy is established using the lattice inversion method, confirming that this potential accurately captures the static physical properties of the multielement alloy. The mechanical behavior of the DZ411 alloy at high temperatures is simulated through molecular dynamics, focusing on i...

Thomson scattering spectra measure the response of plasma particles to incident radiation. In warm dense matter, which is opaque to visible light, x-ray Thomson scattering (XRTS) enables a detailed probe of the electron distribution and has been used as a diagnostic for electron temperature, density, and plasma ionization. In this work, we examine...

How high topography can be sustained over long timescales in post‐orogenic mountain belts is a longstanding research question in tectonic geomorphology and geodynamics. Here we utilize the well‐documented orogenic paleo‐topography and spatial‐temporal exhumation patterns of the Pyrenee Mountains in a numerical modeling study investigating controls...

Because a finite set of measurements is limited in the amount of spectral content it can represent, the reconstruction process from discrete samples is inherently band-limited. In the case of 1D sampling using ideal measurements, the maximum bandwidth of regular and irregular sampling is well known using Nyquist and Gröchenig sampling theorems and...