Accurate forward modeling is of great significance for improving the accuracy and speed inversion. For large sizes fine structures, numerical computational efficiency are not high, due to stability conditions dense grid number. In this paper, symplectic partitioned Runge‐Kutta (SPRK) method, surface conformal technique, graphics processor unit (GPU) acceleration technique combined establish a precise efficient model electromagnetic wave propagation in complex geoelectric with goal realizing...

The finite-difference time-domain (FDTD) method adopts the most popular numerical model simulating ground penetrating radar (GPR) wave propagation in an underground structure. However, a staircase approximation is usually adopted to simulate curved boundary of irregular object FDTD and symplectic partitioned Runge-Kutta (SPRK) methods. approximate processing rectangular mesh parameters will result calculation errors virtual surface waves for targets In this paper, we examine transverse mode...

Numerical simulation of three-layer layered electromagnetic waves is key problem for nondestructive testing ground penetrating radar (GPR) pavement. In this paper, the difference iterative scheme three-dimensional first-order symplectic partitioned Rung-Kutta derived, which applied to pavement detection by using Higdon ABC boundary condition. Incident are considered as line sources. The accuracy and efficiency proposed algorithm verified traditional 3D-FDTD algorithm. results indicate that...

Ground-penetrating radar (GPR) is widely used in the detection and positioning of underground facilities. Through inversion analysis echo signals GPR, information such as pipe material, burial depth location pipelines can be obtained. Unfortunately, are cylindrical, ladder approximation method traditional forward models produces certain errors. In this study, an accurate efficient numerical model GPR established using symplectic Euler algorithm, graphics processing unit (GPU) acceleration...

Ground penetrating radar (GPR), as a kind of fast, effective, and nondestructive tool, has been widely applied to testing road quality. The finite-difference time-domain method (FDTD) is the common numerical studying GPR wave propagation law in layered structure. However, accuracy computational efficiency are not high because Courant-Friedrichs-Lewy (CFL) stability condition. In order improve FDTD simulation model, parallel conformal algorithm based on graphics processor unit (GPU)...

Due to the influence of temperature changes or gradients in construction process mass concrete, cracks will occur concrete. In order achieve a reasonable prediction change concrete during and accurately obtain trend, this paper attempts construct CART model based on big data processing technology characteristics This introduces detail how use methods such as outlier identification, missing value filling random error elimination improve quality, well method for constructing model, combines...

In this paper, the three-dimensional microstructure and anisotropy of CX stainless steel formed by selective laser melting were studied means optical microscope, X-ray diffractom-eter, scanning electron microscope back-scattered diffractometer technique. The results show that temperature gradient high cooling rate have an important influence on SLM steel. is mainly composed a large amount martensite structure small austenite phase struct-ure, obviously different. section, texture <110>...

In this study, we investigate the convergence rates for homogenization of elliptic equations with lower-order terms under spectral gap assumption, in both bounded domains and entire space. Our analysis demonstrates that significantly affect rate, particularly full space, where rate changes from \(O(\epsilon)\) (observed without terms) to \(O(\epsilon^{d/({d+2})})\) due their influence. contrast, domains, remains \(O(\epsilon^{1/2})\), as boundary conditions exert a stronger influence than...

The study of homogenization results has long been a central focus in the field mathematical analysis, particularly for equations without lower-order terms. However, importance studying parabolic with terms cannot be understated. In this study, we aim to extend analysis general equation random coefficients: \begin{equation*} \partial_{t}p^\epsilon-\nabla\cdot\left(\mathbf{a}\left( \dfrac{x}{\epsilon},\dfrac{t}{\epsilon^2}\right)\nabla p^\epsilon\right)-\mathbf{b}\left( p^\epsilon...

Possessing advantages such as high computing efficiency and ease of programming, the Symplectic Euler algorithm can be applied to construct a ground-penetrating radar (GPR) wave propagation numerical model for complex geoelectric structures. However, is still difference algorithm, complicated boundary, ladder grids are needed perform an approximation process, which results in certain amount error. Further, that too dense will seriously decrease efficiency. This paper proposes conformal based...

Measurement of vibration signals were conducted in accelerating and constant velocity travelling conditions. By using time domain, frequency domain 3D spectral array methods, the acceleration passenger’s seat, power assembly suspension, NVH characteristics pure electric bus analyzed. On one hand, we find that level seat increase linearly with speeds. other because poor isolation rate mount chassis on passengers’ seats are very great affecting comfort. These experimental results will give...

Lilium primulinum var. burmanicum (W. W. Smith) Stearn 1948 is an ornamental and medicinal plant that has extremely limited distribution in Yunnan, China. Here, we obtained the complete plastome of L. via next-generation sequencing, conducted phylogenomic analyses with existing species from Lilium. The total length was 152,206 bp a typical quadripartite structure. whole contained pair inverted repeats (IRa/IRb; 26,399 bp) which divided large single-copy (LSC; 81,854 small (SSC; 17,563 bp)....

For hypoid gear which processed by HFT (hypoid formate tilt) method, geometry parameters and machining of were calculated using Gleason card. According to the actual process meshing principle, tooth surface equation was derived coordinate transformation. Then discrete coordinates points obtained MATLAB tools projection transformation data saved in ibl format. At last 3-demensional model established importing format Pro/e.