Due to the poor transition effect of traditional ship track control, the shipping pressure is too large. The research on extrapolation algorithm of ship track smoothing based on spline theory is proposed. Based on the...
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Due to the poor transition effect of traditional ship track control, the shipping pressure is too large. The research on extrapolation algorithm of ship track smoothing based on spline theory is proposed. Based on the principle of spline fitting, a three degree of freedom motion model of ship's horizontal plane is established to analyze the force on the ship in the process of motion, so the motion equation is obtained. The extrapolation algorithm is used to analyze the intersection of wave gates. Considering the actual situation and the influence parameters, the research on extrapolation algorithm of ship track smoothing based on spline theory is completed. The control experiment is designed to compare the track control effect of the proposed algorithm with that of the traditional algorithm. The results show that the combination of the spline theory and the extrapolation method results in a higher fit between the control curve and the actual route, which is obviously superior to the traditional results, and the control effect of the ship track is optimized.
By virtue of its versatile recording geometries, ptychography is a promising full-field lensless phase imaging approach in the prosperous research area of terahertz imaging. In this paper, we propose an extrapolation ...
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By virtue of its versatile recording geometries, ptychography is a promising full-field lensless phase imaging approach in the prosperous research area of terahertz imaging. In this paper, we propose an extrapolation extended ptychographical iterative engine, named as the EE-PIE reconstruction algorithm, to increase the lateral resolution of terahertz ptychography. A divergent spherical beam is applied to illuminate the object, while diffraction patterns are recorded in the Fresnel region. The signal-to-noise ratio of the diffraction patterns is enhanced under divergent probe illumination, while the size of the diffraction patterns is numerically enlarged by the proposed algorithm. Both the reconstruction quality and the resolution are enhanced without adding to the complexity of the setup or increasing the data acquisition time. The proposed method is experimentally demonstrated using a cluster of phylloclades, a patterned polypropylene plate and a Siemens star target. Compared with the planar illumination, the resolution of the divergent spherical illumination is improved by 2.14 times. On this basis, the extrapolation algorithm further improves the experimental resolution by 1.26 times.
In this paper, we use mid-rectangular quadrature rules to solve multidimensional weakly singular integrals of product type (MWSIP) and construct corresponding multi-step and multi-parameter asymptotic expansions of er...
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In this paper, we use mid-rectangular quadrature rules to solve multidimensional weakly singular integrals of product type (MWSIP) and construct corresponding multi-step and multi-parameter asymptotic expansions of errors. The convergence order can turn from O (h(i)(alpha i+1)) to O(h(0)(4)), -1 <= alpha(i) <= 0, h(0) = max(1 <= i <= s) {h(i)} by using extrapolation and splitting extrapolation algorithm. Moreover, we address a posterior error estimate and formulate self-adaptive algorithm. Numerical results illustrate that the method is of high accuracy and efficiency for solving MWSIP.
To reduce the effect of the unreliability of UDP communication on the test of the network servo system, this study aims to propose an improved method by adding data preprocessing layer between the application layer an...
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ISBN:
(纸本)9781509041022
To reduce the effect of the unreliability of UDP communication on the test of the network servo system, this study aims to propose an improved method by adding data preprocessing layer between the application layer and the transport layer on the basis of the UDP communication. According to the different functions of the sender and the recipient in the communication, different improvements are used for the data preprocessing layer. In the case that one or two data packets may be lost, the extrapolation algorithm embedded in data pretreatment layer will be used to extrapolate the lost data packets. The simulation results show that the improved UDP communication can not only improve the reliability of data transmission, but also timely extrapolate the lost data packets when they are lost, which meets the requirement of high real-time capacity for the servo test system.
To reduce the effect of the unreliability of UDP communication on the test of the network servo system, this study aims to propose an improved method by adding data preprocessing layer between the application layer an...
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ISBN:
(纸本)9781509041039
To reduce the effect of the unreliability of UDP communication on the test of the network servo system, this study aims to propose an improved method by adding data preprocessing layer between the application layer and the transport layer on the basis of the UDP communication. According to the different functions of the sender and the recipient in the communication, different improvements are used for the data preprocessing layer. In the case that one or two data packets may be lost, the extrapolation algorithm embedded in data pretreatment layer will be used to extrapolate the lost data packets. The simulation results show that the improved UDP communication can not only improve the reliability of data transmission, but also timely extrapolate the lost data packets when they are lost, which meets the requirement of high real-time capacity for the servo test system.
In order to obtain the numerical solutions of the modified Helmholtz equation with Robin boundary conditions in two dimensions, we have developed a numerical algorithm to solve the problem, which is based on a Nystrom...
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In order to obtain the numerical solutions of the modified Helmholtz equation with Robin boundary conditions in two dimensions, we have developed a numerical algorithm to solve the problem, which is based on a Nystrom discretization. First, the problem is transformed to a weakly-singular integral equation. Then we construct a quadrature method that achieve a convergence rate of O (h3), which has the characteristics of simple calculation and high precision. Further, the convergence of the numerical solutions is proved based on the collectively compact operators theory and the single parameter asymptotic expansion of errors with odd power O(h3) is got. From the expansion, we construct an extrapolation algorithm (EA) to further improve the accuracy of the numerical solutions. Finally, some numerical examples are presented to demonstrate the efficiency of the method. (c) 2023 IMACS. Published by Elsevier B.V. All rights reserved.
In order to obtain the numerical solutions of the axisymmetric Laplace equation with linear boundary problem in three dimensions, we have developed a quadrature method to solve the problem. Firstly, the problem can be...
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In order to obtain the numerical solutions of the axisymmetric Laplace equation with linear boundary problem in three dimensions, we have developed a quadrature method to solve the problem. Firstly, the problem can be transformed to a integral equation with weakly singular operator by using the Green's formula. Secondly, A quadrature method is constructed by combing the mid-rectangle formula with a singular integral formula to solve the integral equation, which has the accuracy of O(h(3)) and low computational complexity. Thirdly, the convergence of the numerical solutions is proved based on the theory of compact operators and the single parameter asymptotic expansion of errors with odd power O(h(3)) is got. From the expansion, we construct an extrapolation algorithm (EA) to further improve the accuracy of the numerical solutions. After one extrapolation, the accuracy of the numerical solutions can reach the accuracy of O(h(5)). Finally, two numerical examples are presented to demonstrate the efficiency of the method.
A constant value of the Relative Biological Effectiveness ( RBE ), equal to 1.1, to weight the physical dose of proton therapy treatment planning collides with the experimental evidence of an increase of effectiveness...
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A constant value of the Relative Biological Effectiveness ( RBE ), equal to 1.1, to weight the physical dose of proton therapy treatment planning collides with the experimental evidence of an increase of effectiveness along the depth dose profile, especially at the end of the particle range. In this context, it is desirable to develop new optimized treatment planning systems that account for a variable RBE when weighting the physical dose. In particular, due to the increasing interest on microdosimetry as a possible methodology for measuring physical quantities correlated with the biological effectiveness of the therapeutic beam, the development of new TissueEquivalent Proportional Counters (TEPCs) specifically designed for the clinical environment are in progress. In this framework, the silicon technology allows to produce solid state detectors of real micrometric dimensions. This is a valid alternative to the TEPC from a practical point of view, being simple, easy-of-use and more versatile. The feasibility of a solid state microdosimeter based on a monolithic double stage silicon telescope has been previously proposed and deeply investigated by comparing its response to the one obtained by reference TEPCs in various radiation fields. The device is constituted by a matrix of cylindrical elements, 2 mu m in thickness and 9 mu m in diameter, coupled to a single E stage, 500 mu m in thickness. Each segmented Delta E stage acts as a solid state microdosimeter, while the E stage gives information on the energy of the impinging proton up to about 8 MeV. This work is dedicated to the description of the microdosimetric characterization of the 148 MeV energymodulated proton beam at the radiobiological research line of the Trento Proton Therapy Centre by means of a pixelated silicon microdosimeter. All measurements were carried out at different positions across the spreadout Bragg peak (SOBP) and the corresponding microdosimetric distributions were derived by applying a nove
For the two-dimensional elasticity problems, we give a uniqueness and existence analysis via the single-layer potential approach leading to a system of integral equation that contains a weakly singular operator. For i...
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For the two-dimensional elasticity problems, we give a uniqueness and existence analysis via the single-layer potential approach leading to a system of integral equation that contains a weakly singular operator. For its numerical solutions we describe a O(h(3)) order quadrature method based on the specific integral formula including convergence and stability analysis. Moreover, the asymptotic expansion of errors with odd power O(h(3)) is got and the accuracy of numerical approximations can be improved to the order of O (h(5)) by the Richardson extrapolation algorithm (EA) once. The efficiency of the method is illustrated by two numerical examples. (c) 2020 IMACS. Published by Elsevier B.V. All rights reserved.
In this paper, we propose a numerical quadrature method for solving two-dimensional linear and nonlinear Volterra integral equations. Firstly, we generalize one-dimensional quadrature formula to two-dimensional case a...
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In this paper, we propose a numerical quadrature method for solving two-dimensional linear and nonlinear Volterra integral equations. Firstly, we generalize one-dimensional quadrature formula to two-dimensional case and its corresponding error asymptotic expansion. Based on the quadrature formula and the error expansion, we next construct an iterative scheme and extrapolation algorithm. The numerical solution of any point can be calculated by iterative scheme, and the error accuracy and convergence order of the numerical solution are further improved by extrapolation algorithm. Using the extrapolation algorithm, we can improve the convergence order from O(h(0)(2)) to O(h(0)(3)) or even O(h(0)(4)). Since, the numerical solution of each point is obtained by assignment operation and iteration, the computational complexity can be greatly reduced. Finally, four numerical examples are given to illustrate the effectiveness of the method. (C) 2019 Elsevier Inc. All rights reserved.
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