Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high com...Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high computational complexity and insufficient capture of high-frequency phase aberration components,so we proposed a Principal-Component-Analysis-based method for representing phase aberrations.This paper discusses the factors influencing the accuracy of restoration,mainly including the sample space size and the sampling interval of D/r_(0),on the basis of characterizing phase aberrations by Principal Components(PCs).The experimental results show that a larger D/r_(0)sampling interval can ensure the generalization ability and robustness of the principal components in the case of a limited amount of original data,which can help to achieve high-precision deployment of the model in practical applications quickly.In the environment with relatively strong turbulence in the test set of D/r_(0)=24,the use of 34 terms of PCs can improve the corrected Strehl ratio(SR)from 0.007 to 0.1585,while the Strehl ratio of the light spot after restoration using 34 terms of ZPs is only 0.0215,demonstrating almost no correction effect.The results indicate that PCs can serve as a better alternative in representing and restoring the characteristics of atmospheric turbulence induced phase aberrations.These findings pave the way to use PCs of phase aberrations with fewer terms than traditional ZPs to achieve data dimensionality reduction,and offer a reference to accelerate and stabilize the model and deep learning based adaptive optics correction.展开更多
The capabilities of GIS for constructing a digital elevation model of a mountainous area and visualizing a spatial image of the terrain are given in this paper.Graphic,digital data and topographic maps,which are the m...The capabilities of GIS for constructing a digital elevation model of a mountainous area and visualizing a spatial image of the terrain are given in this paper.Graphic,digital data and topographic maps,which are the main sources for GIS,are described.The methods of vectorization of isolines and the requirements for technical means of processing graphic materials are presented in detail.The advantages and disadvantages of the DEM of a mountainous region are shown here.Segmentation methods using an interpolation polynomial are described in detail.A DEM of the mountainous area where the border between the republics runs was constructed in 2D and 3D formats using the GIS Panorama.Reducing the chord length when segmenting isolines on topographic maps leads to more accurate DEM construction.A vertical profile of a mountainous area with a visibility zone between two points was constructed.It is expected that the improved latitude,longitude and altitude parameters of the topographic map will be used to form a regional geodetic network and geospatial analysis of mountain ranges.It is proposed to use not only satellite data,but also classical geodetic networks and maps.It is recommended to use satellite and aerial photography to clarify the topographic and geodetic support of the studied area.展开更多
This paper investigates the asymptotic behavior of high-order vector rogue wave(RW)solutions for any multi-component nonlinear Schr¨odinger equation(denoted as n-NLSE)with multiple internal large parameters.We re...This paper investigates the asymptotic behavior of high-order vector rogue wave(RW)solutions for any multi-component nonlinear Schr¨odinger equation(denoted as n-NLSE)with multiple internal large parameters.We report some novel RW patterns,including nonmultiple root(NMR)-type patterns with distinct shapes such as semicircular sector,acute sector,pseudo-hexagram,and pseudo-rhombus shapes,as well as multiple root(MR)-type patterns characterized by right double-arrow and right arrow shapes.We demonstrate that these RW patterns are intrinsically related to the root structures of a novel class of polynomials,termed generalized mixed Adler-Moser(GMAM)polynomials,which feature multiple arbitrary free parameters.The RW patterns can be interpreted as straightforward expansions and slight shifts of the root structures for the GMAM polynomials to some extent.In the(x,t)-plane,they asymptotically converge to a first-order RW at the location corresponding to each simple root of the polynomials and to a lower-order RW at the location associated with each multiple root.Notably,the position of the lower-order RW within these patterns can be flexibly adjusted to any desired location in the(x,t)-plane by tuning the free parameters of the corresponding GMAM polynomials.展开更多
Background:Schistosomiasis is a parasitic disease.It is caused by a prevalent infection in tropical areas and is transmitted through contaminated water with larvae parasites.Schistosomiasis is the second most parasiti...Background:Schistosomiasis is a parasitic disease.It is caused by a prevalent infection in tropical areas and is transmitted through contaminated water with larvae parasites.Schistosomiasis is the second most parasitic disease globally,so investigating its prevention and treatment is crucial.Methods:This paper aims to suggest a time-fractional model of schistosomiasis disease(T-FMSD)in the sense of the Caputo operator.The T-FMSD considers the dynamics involving susceptible ones not infected with schistosomiasis(S_(h)(t)),those infected with the infection(Ih(t)),those recovering from the disease(R(t)),susceptible snails with and without schistosomiasis infection,respectively shown by I_(v)(t)and S_(v)(t).We use a new basis function,generalized Bernoulli polynomials,for the approximate solution of T-FMSD.The operational matrices are incorporated into the method of Lagrange multipliers so that the fractional problem can be transformed into an algebraic system of equations.Results:The existence and uniqueness of the solution,and the convergence analysis of the model are established.The numerical computations are graphically presented to depict the variations of the compartments with time for varied fractional order derivatives.Conclusions:The proposed method not only provides an accurate solution but also can accurately predict schistosomiasis transmission.The results of this study will assist medical scientists in taking necessary measures during screening and treatment processes.展开更多
This work’s aim is to participate in local materials (raw or fiber improved), which can be used in sustainable and accessible buildings to every Senegalese. To do this, studied materials are respectively collected fr...This work’s aim is to participate in local materials (raw or fiber improved), which can be used in sustainable and accessible buildings to every Senegalese. To do this, studied materials are respectively collected from a laterite clay pit in Ndouloumadjie Dembe (Matam, Northern Senegal) and another from a termite mound in Tattaguine (Fatick, Central Senegal). These samples are first subjected to Geotechnical identification tests. Mud bricks are then made with raw or sifted millet involucre improved to 1%, 2%, and 3% at 5 mm sieve samples. These briquettes are subjected to compression tests and thermal evaluations. Lagrange and Newton methods of numeric modelling are used to test the whole mixture points between 1% and 3% millet involucre for a better correlation between mechanical and thermal parameters. The results show that in Matam, as well as in Tattaguine, these muds, raw or improved, are of good thermomechanical quality when they are used in bricks making. And the thermomechanical coupling quality reaches a maximum situated at 2.125% for Ndouloumadjie and 2.05% for Tattaguine. These briquettes’ building quality depends on the mud content used in iron, aluminum, silica and clay. Thus, same natural materials can be used in the establishment of habitats according to their geotechnical, chemical, mechanical and thermal characteristics.展开更多
Seismic wavefields propagate through three-dimensional(3D)space,and their precise characterization is crucial for understanding subsurface structures.Traditional 2D algorithms,due to their limitations,are insufficient...Seismic wavefields propagate through three-dimensional(3D)space,and their precise characterization is crucial for understanding subsurface structures.Traditional 2D algorithms,due to their limitations,are insufficient to fully represent three-dimensional wavefields.The classic 3D Radon transform algorithm assumes that the wavefield's propagation characteristics are consistent in all directions,which often does not hold true in complex underground media.To address this issue,we present an improved 3D three-parameter Radon algorithm that considers the wavefield variation with azimuth and provides a more accurate wavefield description.However,introducing new parameters to describe the azimuthal varia-tion also poses computational challenges.The new Radon transform operator involves five variables and cannot be simply decomposed into small matrices for efficient computation;instead,it requires large matrix multiplication and inversion operations,significantly increasing the computational load.To overcome this challenge,we have integrated the curvature and frequency parameters,simplifying all frequency operators to the same,thereby significantly improving computation efficiency.Furthermore,existing transform algorithms neglect the lateral variation of seismic amplitudes,leading to discrepancies between the estimated multiples and those in the data.To enhance the amplitude preservation of the algorithm,we employ orthogonal polynomial fitting to capture the amplitude spatial variation in 3D seismic data.Combining these improvements,we propose a fast,amplitude-preserving,3D three-parameter Radon transform algorithm.This algorithm not only enhances computational efficiency while maintaining the original wavefield characteristics,but also improves the representation of seismic data by increasing amplitude fidelity.We validated the algorithm in multiple attenuation using both synthetic and real seismic data.The results demonstrate that the new algorithm significantly improves both accuracy and computational efficiency,providing an effective tool for analyzing seismic wavefields in complex subsurface structures.展开更多
Throughout this work,we explore the uniqueness properties of meromorphic functions concerning their interactions with complex differential-difference polynomial.Under the condition of finite order,we establish three d...Throughout this work,we explore the uniqueness properties of meromorphic functions concerning their interactions with complex differential-difference polynomial.Under the condition of finite order,we establish three distinct uniqueness results for a meromorphic function f associated with the differential-difference polynomial L_(η)^(n)f=Σ_(k=0)^(n)a_(k)f (z+k_(η))+a_(-1)f′.These results lead to a refined characterization of f (z)≡L_(η)^(n)f (z).Several illustrative examples are provided to demonstrate the sharpness and precision of the results obtained in this study.展开更多
Autonomous trucks have the potential to enhance both safety and convenience in intelligent transportation.However,their maximum speed and ability to navigate a variety of driving conditions,particularly uneven roads,a...Autonomous trucks have the potential to enhance both safety and convenience in intelligent transportation.However,their maximum speed and ability to navigate a variety of driving conditions,particularly uneven roads,are limited by a high center of gravity,which increases the risk of rollover.Road bulges,sinkholes,and unexpected debris all present additional challenges for autonomous trucks’operational design,which current perception and decisionmaking algorithms often overlook.To mitigate rollover risks and improve adaptability to damaged roads,this paper presents a novel Road Obstacle-Involved Trajectory Planner(ROITP).The planner categorizes road obstacles using a learning-based algorithm.A discrete optimization algorithm selects a multi-objective optimal trajectory while taking into account constraints and objective functions derived from truck dynamics.Validation across various scenarios on a hardware-in-loop platform demonstrates that the proposed planner is effective and feasible for real-time implementation.展开更多
The ice accretion on the wing surface of aircraft significantly impacts flight safety.Providing a precise safety assessment by examining flight characteristics and meteorological conditions is challenging.Based on dif...The ice accretion on the wing surface of aircraft significantly impacts flight safety.Providing a precise safety assessment by examining flight characteristics and meteorological conditions is challenging.Based on different swept angles,the experimental data from the icing wind tunnel establish the geometric link between the position of the wingspan and the shape of ice accretion at the leading edge.The correlation analysis and Sobol sensitivity are used to study the uncertainty of single variable.Simultaneously,the polynomial chaos method is employed to study the uncertainty of multiple variables.The results indicate significant correlation between the angle of attack and lift and drag coefficients.The influence of height and velocity on sensitivity is negligible,with the aerodynamic characteristics mostly dependent on the geometric attributes of the ice structure.The uncertainty propagation framework established can accurately assess the impact of swept angle on the aerodynamic parameters of the icing wing,and the predicted findings fall within a 95%confidence interval.展开更多
Gear flank modification is essential to reduce the noise generated in the gear meshing process,improve the gear transmission performance,and reduce the meshing impact.Aiming at the problem of solving the additional mo...Gear flank modification is essential to reduce the noise generated in the gear meshing process,improve the gear transmission performance,and reduce the meshing impact.Aiming at the problem of solving the additional motions of each axis in the higher-order topology modification technique and how to accurately add the different movements expressed in the form of higher-order polynomials to the corresponding motion axes of the machine tool,a flexible higher-order gear topology modification technique based on an electronic gearbox is proposed.Firstly,a two-parameter topology gear surface equation and a grinding model of wheel grinding gears are established,and the axial feed and tangential feed are expressed in a fifth-order polynomial formula.Secondly,the polynomial coefficients are solved according to the characteristics of the point contact when grinding gears.Finally,an improved electronic gearbox model is constructed by combining the polynomial interpolation function to achieve gear topology modification.The validity and feasibility of the modification method based on the electronic gearbox are verified by experimental examples,which is of great significance for the machining of modification gears based on the continuous generative grinding method of the worm grinding wheel.展开更多
This study experimentally investigates the operational performance of a scroll compressor using R513A to expand its application range as a substitute for R134a.A vapor compression heat pump test platform was establish...This study experimentally investigates the operational performance of a scroll compressor using R513A to expand its application range as a substitute for R134a.A vapor compression heat pump test platform was established to analyze the variation trends of heating capacity,refrigerant mass flow rate,compressor power consumption,and current by controlling the compressor inlet and outlet pressures(i.e.,evaporating and condensing temperatures).The results indicate that both heating capacity and refrigerant mass flow rate decrease with increasing pressure ratio.Compressor power consumption and current initially increase and then decrease with rising evaporating temperature,whereas they exhibit an approximately linear positive correlation with condensing temperature.Based on the experimental data,a polynomial model with pressure ratio as the independent variable was developed.This model predicts heating capacity,mass flow rate,power consumption,and current with high accuracy,showing an average deviation of less than 2%.However,the model’s applicability is significantly influenced by evaporating and condensing temperatures.Therefore,an enhanced 10-coefficient polynomial model,incorporating both evaporating and condensing temperatures as independent variables,was established.This improved model eliminates operational limitations and demonstrates superior prediction performance,with an average deviation of±1.44%for compressor performance parameters,confirming its practical value for engineering applications.展开更多
We consider the space and time decays of certain problems within the second gradient thermal law.Notably,for this thermal theory,the exponential time decay is precluded.First,the time estimates of polynomial type are ...We consider the space and time decays of certain problems within the second gradient thermal law.Notably,for this thermal theory,the exponential time decay is precluded.First,the time estimates of polynomial type are obtained for both the thermal equation and the one-dimensional thermoelastic system,where the impossibility of localization with respect to time is also established.Then,the space estimates are deduced for the multidimensional thermoelastic problem,which allow to show the exponential decay of the energy.展开更多
In this article,we study the meromorphic solutions of the following non-linear differential equation■where n and k are integers with n≥k≥3,P_(d)(z,f)is a differential polynomial in f of degree d≤n−1,p′js andα′j...In this article,we study the meromorphic solutions of the following non-linear differential equation■where n and k are integers with n≥k≥3,P_(d)(z,f)is a differential polynomial in f of degree d≤n−1,p′js andα′js are non-zero constants.We obtain the expressions of meromorphic solutions of the above equations under some restrictions onα′js.Some examples are given to illustrate the possibilities of our results.展开更多
Economic losses and catastrophic casualties may occur once super high-rise structures are struck by low-probability but high-consequence scenarios of concurrent earthquakes and winds. Therefore, accurately predicting ...Economic losses and catastrophic casualties may occur once super high-rise structures are struck by low-probability but high-consequence scenarios of concurrent earthquakes and winds. Therefore, accurately predicting multi-hazard dynamic responses to super high-rise structures has significant engineering and scientific value. This study performed a parametric global sensitivity analysis (GSA) for multi-hazard dynamic response prediction of super high-rise structures using the multiple-degree-of-freedom shear (MFS) model. Polynomial chaos Kriging (PCK) was introduced to build a surrogate model that allowed GSA to be combined with Sobol’ indices. Monte Carlo simulation (MCS) is also conducted for the comparison to verify the accuracy and efficiency of the PCK method. Parametric sensitivity analysis is performed for a wide range of aleatory uncertainty (intensities of coupled multi-hazard), epistemic uncertainty (bending stiffness, k_(m);shear stiffness, kq;density, ρ;and damping ratio, ξ), probability distribution types, and coefficients of variation. The results indicate that epistemic uncertainty parameters, k_(m), ρ, and ξ dramatically affect the multi-hazard dynamic responses of super high-rise structures;in addition, Sobol’ indices between the normal and lognormal distributions are insignificant, while the variation levels have remarkably influenced the sensitivity indices.展开更多
Photomechanics is a crucial branch of solid mechanics.The localization of point targets constitutes a fundamental problem in optical experimental mechanics,with extensive applications in various missions of unmanned a...Photomechanics is a crucial branch of solid mechanics.The localization of point targets constitutes a fundamental problem in optical experimental mechanics,with extensive applications in various missions of unmanned aerial vehicles.Localizing moving targets is crucial for analyzing their motion characteristics and dynamic properties.Reconstructing the trajectories of points from asynchronous cameras is a significant challenge.It encompasses two coupled sub-problems:Trajectory reconstruction and camera synchronization.Present methods typically address only one of these sub-problems individually.This paper proposes a 3D trajectory reconstruction method for point targets based on asynchronous cameras,simultaneously solving both sub-problems.Firstly,we extend the trajectory intersection method to asynchronous cameras to resolve the limitation of traditional triangulation that requires camera synchronization.Secondly,we develop models for camera temporal information and target motion,based on imaging mechanisms and target dynamics characteristics.The parameters are optimized simultaneously to achieve trajectory reconstruction without accurate time parameters.Thirdly,we optimize the camera rotations alongside the camera time information and target motion parameters,using tighter and more continuous constraints on moving points.The reconstruction accuracy is significantly improved,especially when the camera rotations are inaccurate.Finally,the simulated and real-world experimental results demonstrate the feasibility and accuracy of the proposed method.The real-world results indicate that the proposed algorithm achieved a localization error of 112.95 m at an observation distance range of 15-20 km.展开更多
Fins are extensively utilized in heat exchangers and various industrial applications as they are lightweight and can benefit in various systems,including electronic cooling devices and automotive components,owing to t...Fins are extensively utilized in heat exchangers and various industrial applications as they are lightweight and can benefit in various systems,including electronic cooling devices and automotive components,owing to their adaptable design.Furthermore,spine fins are introduced to improve performance in applications such as automotive radiators.They can be shaped in different ways and constructed from a collection of materials.Inspired by this,the present model examines the effects of internal heat generation and radiation-convection on the thermal distribution in a wetted convex-shaped spine fin.Using dimensionless terms,the proposed fin model involving a governing nonlinear ordinary differential equation(ODE)is transformed into a dimensionless form.The study uses the operational matrix with the Charlier polynomial collocation method(OMCCM)to ensure precise and computationally efficient numerical solutions for the dimensionless equation.In order to aid in the analysis of thermal performance,the importance of major parameters on the temperature profile is graphically illustrated.The main outcome of the study reveals that as the radiation-conductive,wet,and convective-conductive parameters increase,the heat transfer rate progressively improves.Conversely,the ambient temperature and internal heat generation parameters show an inverse relationship.展开更多
In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in ...In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in this paper,we prove that rooted products of some trees preserve real-rootedness of independence polynomials.In particular,we can obtain that their independence polynomials are unimodal and log-concave.展开更多
This paper investigates set-valued state estimation of nonlinear systems with unknown-but-bounded(UBB)noises based on constrained polynomial zonotopes which is utilized to characterize non-convex sets.First,properties...This paper investigates set-valued state estimation of nonlinear systems with unknown-but-bounded(UBB)noises based on constrained polynomial zonotopes which is utilized to characterize non-convex sets.First,properties of constrained polynomial zonotopes are provided and the order reduction method is given to reduce the computational complexity.Then,the corresponding improved prediction-update algorithm is proposed so that it can be adapted to non-convex sets.Based on generalized intersection,the utilization of set-based estimation for attack detection is analyzed.Finally,an example is given to show the efficiency of our results.展开更多
In this paper, two new efficient fully nonconforming polynomial finite element methods on arbitrary convex quadrilaterals are constructed to solve the Brinkman problem. Both elements have 12 local degrees of freedom a...In this paper, two new efficient fully nonconforming polynomial finite element methods on arbitrary convex quadrilaterals are constructed to solve the Brinkman problem. Both elements have 12 local degrees of freedom and are uniformly first-order convergent. For the first element, we carefully design a shape function space of only degree four, which is convenient for practical computation. Meanwhile, the velocity solution obtained by our second element has O(h^(2)) convergence order in the case of Darcy limit. These new elements can be regarded as modifications of a known element to effectively improve the computational efficiency, only the shape function space is properly changed. We verify our theoretical findings by numerical examples.展开更多
This paper proposes a concurrent neural network model to mitigate non-linear distortion in power amplifiers using a basis function generation approach.The model is designed using polynomial expansion and comprises a f...This paper proposes a concurrent neural network model to mitigate non-linear distortion in power amplifiers using a basis function generation approach.The model is designed using polynomial expansion and comprises a feedforward neural network(FNN)and a convolutional neural network(CNN).The proposed model takes the basic elements that form the bases as input,defined by the generalized memory polynomial(GMP)and dynamic deviation reduction(DDR)models.The FNN generates the basis function and its output represents the basis values,while the CNN generates weights for the corresponding bases.Through the concurrent training of FNN and CNN,the hidden layer coefficients are updated,and the complex multiplication of their outputs yields the trained in-phase/quadrature(I/Q)signals.The proposed model was trained and tested using 300 MHz and 400 MHz broadband data in an orthogonal frequency division multiplexing(OFDM)communication system.The results show that the model achieves an adjacent channel power ratio(ACPR)of less than-48 d B within a 100 MHz integral bandwidth for both the training and test datasets.展开更多
文摘Restoration of phase aberrations is crucial for addressing atmospheric turbulence in light propagation.Traditional restoration algorithms based on Zernike polynomials(ZPs)often encounter challenges related to high computational complexity and insufficient capture of high-frequency phase aberration components,so we proposed a Principal-Component-Analysis-based method for representing phase aberrations.This paper discusses the factors influencing the accuracy of restoration,mainly including the sample space size and the sampling interval of D/r_(0),on the basis of characterizing phase aberrations by Principal Components(PCs).The experimental results show that a larger D/r_(0)sampling interval can ensure the generalization ability and robustness of the principal components in the case of a limited amount of original data,which can help to achieve high-precision deployment of the model in practical applications quickly.In the environment with relatively strong turbulence in the test set of D/r_(0)=24,the use of 34 terms of PCs can improve the corrected Strehl ratio(SR)from 0.007 to 0.1585,while the Strehl ratio of the light spot after restoration using 34 terms of ZPs is only 0.0215,demonstrating almost no correction effect.The results indicate that PCs can serve as a better alternative in representing and restoring the characteristics of atmospheric turbulence induced phase aberrations.These findings pave the way to use PCs of phase aberrations with fewer terms than traditional ZPs to achieve data dimensionality reduction,and offer a reference to accelerate and stabilize the model and deep learning based adaptive optics correction.
文摘The capabilities of GIS for constructing a digital elevation model of a mountainous area and visualizing a spatial image of the terrain are given in this paper.Graphic,digital data and topographic maps,which are the main sources for GIS,are described.The methods of vectorization of isolines and the requirements for technical means of processing graphic materials are presented in detail.The advantages and disadvantages of the DEM of a mountainous region are shown here.Segmentation methods using an interpolation polynomial are described in detail.A DEM of the mountainous area where the border between the republics runs was constructed in 2D and 3D formats using the GIS Panorama.Reducing the chord length when segmenting isolines on topographic maps leads to more accurate DEM construction.A vertical profile of a mountainous area with a visibility zone between two points was constructed.It is expected that the improved latitude,longitude and altitude parameters of the topographic map will be used to form a regional geodetic network and geospatial analysis of mountain ranges.It is proposed to use not only satellite data,but also classical geodetic networks and maps.It is recommended to use satellite and aerial photography to clarify the topographic and geodetic support of the studied area.
基金supported by the NSFC(12471236)the Guangzhou Municipal Science and Technology Project(Guangzhou Science and Technology Plan,No.2024A04J6245)Guangdong Natural Science Foundation(2025A1515011868)。
文摘This paper investigates the asymptotic behavior of high-order vector rogue wave(RW)solutions for any multi-component nonlinear Schr¨odinger equation(denoted as n-NLSE)with multiple internal large parameters.We report some novel RW patterns,including nonmultiple root(NMR)-type patterns with distinct shapes such as semicircular sector,acute sector,pseudo-hexagram,and pseudo-rhombus shapes,as well as multiple root(MR)-type patterns characterized by right double-arrow and right arrow shapes.We demonstrate that these RW patterns are intrinsically related to the root structures of a novel class of polynomials,termed generalized mixed Adler-Moser(GMAM)polynomials,which feature multiple arbitrary free parameters.The RW patterns can be interpreted as straightforward expansions and slight shifts of the root structures for the GMAM polynomials to some extent.In the(x,t)-plane,they asymptotically converge to a first-order RW at the location corresponding to each simple root of the polynomials and to a lower-order RW at the location associated with each multiple root.Notably,the position of the lower-order RW within these patterns can be flexibly adjusted to any desired location in the(x,t)-plane by tuning the free parameters of the corresponding GMAM polynomials.
文摘Background:Schistosomiasis is a parasitic disease.It is caused by a prevalent infection in tropical areas and is transmitted through contaminated water with larvae parasites.Schistosomiasis is the second most parasitic disease globally,so investigating its prevention and treatment is crucial.Methods:This paper aims to suggest a time-fractional model of schistosomiasis disease(T-FMSD)in the sense of the Caputo operator.The T-FMSD considers the dynamics involving susceptible ones not infected with schistosomiasis(S_(h)(t)),those infected with the infection(Ih(t)),those recovering from the disease(R(t)),susceptible snails with and without schistosomiasis infection,respectively shown by I_(v)(t)and S_(v)(t).We use a new basis function,generalized Bernoulli polynomials,for the approximate solution of T-FMSD.The operational matrices are incorporated into the method of Lagrange multipliers so that the fractional problem can be transformed into an algebraic system of equations.Results:The existence and uniqueness of the solution,and the convergence analysis of the model are established.The numerical computations are graphically presented to depict the variations of the compartments with time for varied fractional order derivatives.Conclusions:The proposed method not only provides an accurate solution but also can accurately predict schistosomiasis transmission.The results of this study will assist medical scientists in taking necessary measures during screening and treatment processes.
文摘This work’s aim is to participate in local materials (raw or fiber improved), which can be used in sustainable and accessible buildings to every Senegalese. To do this, studied materials are respectively collected from a laterite clay pit in Ndouloumadjie Dembe (Matam, Northern Senegal) and another from a termite mound in Tattaguine (Fatick, Central Senegal). These samples are first subjected to Geotechnical identification tests. Mud bricks are then made with raw or sifted millet involucre improved to 1%, 2%, and 3% at 5 mm sieve samples. These briquettes are subjected to compression tests and thermal evaluations. Lagrange and Newton methods of numeric modelling are used to test the whole mixture points between 1% and 3% millet involucre for a better correlation between mechanical and thermal parameters. The results show that in Matam, as well as in Tattaguine, these muds, raw or improved, are of good thermomechanical quality when they are used in bricks making. And the thermomechanical coupling quality reaches a maximum situated at 2.125% for Ndouloumadjie and 2.05% for Tattaguine. These briquettes’ building quality depends on the mud content used in iron, aluminum, silica and clay. Thus, same natural materials can be used in the establishment of habitats according to their geotechnical, chemical, mechanical and thermal characteristics.
基金supported in part by National Natural Science Foundation of China(NSFC)under grant 42274139in part by the R&D Department of China National Petroleum Corporation(Investigations on fundamental experiments and advanced theoretical methods in geophysical prospecting applications,2022DQ0604-03).
文摘Seismic wavefields propagate through three-dimensional(3D)space,and their precise characterization is crucial for understanding subsurface structures.Traditional 2D algorithms,due to their limitations,are insufficient to fully represent three-dimensional wavefields.The classic 3D Radon transform algorithm assumes that the wavefield's propagation characteristics are consistent in all directions,which often does not hold true in complex underground media.To address this issue,we present an improved 3D three-parameter Radon algorithm that considers the wavefield variation with azimuth and provides a more accurate wavefield description.However,introducing new parameters to describe the azimuthal varia-tion also poses computational challenges.The new Radon transform operator involves five variables and cannot be simply decomposed into small matrices for efficient computation;instead,it requires large matrix multiplication and inversion operations,significantly increasing the computational load.To overcome this challenge,we have integrated the curvature and frequency parameters,simplifying all frequency operators to the same,thereby significantly improving computation efficiency.Furthermore,existing transform algorithms neglect the lateral variation of seismic amplitudes,leading to discrepancies between the estimated multiples and those in the data.To enhance the amplitude preservation of the algorithm,we employ orthogonal polynomial fitting to capture the amplitude spatial variation in 3D seismic data.Combining these improvements,we propose a fast,amplitude-preserving,3D three-parameter Radon transform algorithm.This algorithm not only enhances computational efficiency while maintaining the original wavefield characteristics,but also improves the representation of seismic data by increasing amplitude fidelity.We validated the algorithm in multiple attenuation using both synthetic and real seismic data.The results demonstrate that the new algorithm significantly improves both accuracy and computational efficiency,providing an effective tool for analyzing seismic wavefields in complex subsurface structures.
基金Supported by the National Natural Science Foundation of China (Grant No.12161074)the Talent Introduction Research Foundation of Suqian University (Grant No.106-CK00042/028)+1 种基金Suqian Sci&Tech Program (Grant No.M202206)Sponsored by Qing Lan Project of Jiangsu Province and Suqian Talent Xiongying Plan of Suqian。
文摘Throughout this work,we explore the uniqueness properties of meromorphic functions concerning their interactions with complex differential-difference polynomial.Under the condition of finite order,we establish three distinct uniqueness results for a meromorphic function f associated with the differential-difference polynomial L_(η)^(n)f=Σ_(k=0)^(n)a_(k)f (z+k_(η))+a_(-1)f′.These results lead to a refined characterization of f (z)≡L_(η)^(n)f (z).Several illustrative examples are provided to demonstrate the sharpness and precision of the results obtained in this study.
基金Supported by National Natural Science Foundation of China (Grant Nos. 52072215, 52221005, 52272386)Beijing Municipal Natrual Science Foundation (Grant No. L243025)+2 种基金National Key R&D Program of China (Grant No. 2022YFB2503003)State Key Laboratory of Intelligent Green Vehicle and Mobilityfundamental Research Funds for the Central Universities
文摘Autonomous trucks have the potential to enhance both safety and convenience in intelligent transportation.However,their maximum speed and ability to navigate a variety of driving conditions,particularly uneven roads,are limited by a high center of gravity,which increases the risk of rollover.Road bulges,sinkholes,and unexpected debris all present additional challenges for autonomous trucks’operational design,which current perception and decisionmaking algorithms often overlook.To mitigate rollover risks and improve adaptability to damaged roads,this paper presents a novel Road Obstacle-Involved Trajectory Planner(ROITP).The planner categorizes road obstacles using a learning-based algorithm.A discrete optimization algorithm selects a multi-objective optimal trajectory while taking into account constraints and objective functions derived from truck dynamics.Validation across various scenarios on a hardware-in-loop platform demonstrates that the proposed planner is effective and feasible for real-time implementation.
基金supported by the National Natural Science Foundation of China(No.92371201)the State Key Laboratory for Strength and Vibration of Mechanical Structures Program,China.Thanks to China Aerodynamics Research and Development Center for providing the experimental data.
文摘The ice accretion on the wing surface of aircraft significantly impacts flight safety.Providing a precise safety assessment by examining flight characteristics and meteorological conditions is challenging.Based on different swept angles,the experimental data from the icing wind tunnel establish the geometric link between the position of the wingspan and the shape of ice accretion at the leading edge.The correlation analysis and Sobol sensitivity are used to study the uncertainty of single variable.Simultaneously,the polynomial chaos method is employed to study the uncertainty of multiple variables.The results indicate significant correlation between the angle of attack and lift and drag coefficients.The influence of height and velocity on sensitivity is negligible,with the aerodynamic characteristics mostly dependent on the geometric attributes of the ice structure.The uncertainty propagation framework established can accurately assess the impact of swept angle on the aerodynamic parameters of the icing wing,and the predicted findings fall within a 95%confidence interval.
基金Projects(52275483,52075142,U22B2084)supported by the National Natural Science Foundation of ChinaProject(JZ2023HGPA0292)supported by the Fundamental Research Funds for the Central Universities of China。
文摘Gear flank modification is essential to reduce the noise generated in the gear meshing process,improve the gear transmission performance,and reduce the meshing impact.Aiming at the problem of solving the additional motions of each axis in the higher-order topology modification technique and how to accurately add the different movements expressed in the form of higher-order polynomials to the corresponding motion axes of the machine tool,a flexible higher-order gear topology modification technique based on an electronic gearbox is proposed.Firstly,a two-parameter topology gear surface equation and a grinding model of wheel grinding gears are established,and the axial feed and tangential feed are expressed in a fifth-order polynomial formula.Secondly,the polynomial coefficients are solved according to the characteristics of the point contact when grinding gears.Finally,an improved electronic gearbox model is constructed by combining the polynomial interpolation function to achieve gear topology modification.The validity and feasibility of the modification method based on the electronic gearbox are verified by experimental examples,which is of great significance for the machining of modification gears based on the continuous generative grinding method of the worm grinding wheel.
基金supported by Henan province key science and technology research projects with No.23A560018.
文摘This study experimentally investigates the operational performance of a scroll compressor using R513A to expand its application range as a substitute for R134a.A vapor compression heat pump test platform was established to analyze the variation trends of heating capacity,refrigerant mass flow rate,compressor power consumption,and current by controlling the compressor inlet and outlet pressures(i.e.,evaporating and condensing temperatures).The results indicate that both heating capacity and refrigerant mass flow rate decrease with increasing pressure ratio.Compressor power consumption and current initially increase and then decrease with rising evaporating temperature,whereas they exhibit an approximately linear positive correlation with condensing temperature.Based on the experimental data,a polynomial model with pressure ratio as the independent variable was developed.This model predicts heating capacity,mass flow rate,power consumption,and current with high accuracy,showing an average deviation of less than 2%.However,the model’s applicability is significantly influenced by evaporating and condensing temperatures.Therefore,an enhanced 10-coefficient polynomial model,incorporating both evaporating and condensing temperatures as independent variables,was established.This improved model eliminates operational limitations and demonstrates superior prediction performance,with an average deviation of±1.44%for compressor performance parameters,confirming its practical value for engineering applications.
基金part of the project“Qualitative and numerical analyses of some thermomechanics problems(ACUANUTER)”(Ref.PID2024-156827NB-I00)。
文摘We consider the space and time decays of certain problems within the second gradient thermal law.Notably,for this thermal theory,the exponential time decay is precluded.First,the time estimates of polynomial type are obtained for both the thermal equation and the one-dimensional thermoelastic system,where the impossibility of localization with respect to time is also established.Then,the space estimates are deduced for the multidimensional thermoelastic problem,which allow to show the exponential decay of the energy.
基金supported by the National Natural Science Foundation of China(No.12001117)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110654).
文摘In this article,we study the meromorphic solutions of the following non-linear differential equation■where n and k are integers with n≥k≥3,P_(d)(z,f)is a differential polynomial in f of degree d≤n−1,p′js andα′js are non-zero constants.We obtain the expressions of meromorphic solutions of the above equations under some restrictions onα′js.Some examples are given to illustrate the possibilities of our results.
基金Dalian Municipal Natural Science Foundation under Grant No.2019RD01。
文摘Economic losses and catastrophic casualties may occur once super high-rise structures are struck by low-probability but high-consequence scenarios of concurrent earthquakes and winds. Therefore, accurately predicting multi-hazard dynamic responses to super high-rise structures has significant engineering and scientific value. This study performed a parametric global sensitivity analysis (GSA) for multi-hazard dynamic response prediction of super high-rise structures using the multiple-degree-of-freedom shear (MFS) model. Polynomial chaos Kriging (PCK) was introduced to build a surrogate model that allowed GSA to be combined with Sobol’ indices. Monte Carlo simulation (MCS) is also conducted for the comparison to verify the accuracy and efficiency of the PCK method. Parametric sensitivity analysis is performed for a wide range of aleatory uncertainty (intensities of coupled multi-hazard), epistemic uncertainty (bending stiffness, k_(m);shear stiffness, kq;density, ρ;and damping ratio, ξ), probability distribution types, and coefficients of variation. The results indicate that epistemic uncertainty parameters, k_(m), ρ, and ξ dramatically affect the multi-hazard dynamic responses of super high-rise structures;in addition, Sobol’ indices between the normal and lognormal distributions are insignificant, while the variation levels have remarkably influenced the sensitivity indices.
基金supported by the Hunan Provin〓〓cial Natural Science Foundation for Excellent Young Scholars(Grant No.2023JJ20045)the National Natural Science Foundation of China(Grant No.12372189)。
文摘Photomechanics is a crucial branch of solid mechanics.The localization of point targets constitutes a fundamental problem in optical experimental mechanics,with extensive applications in various missions of unmanned aerial vehicles.Localizing moving targets is crucial for analyzing their motion characteristics and dynamic properties.Reconstructing the trajectories of points from asynchronous cameras is a significant challenge.It encompasses two coupled sub-problems:Trajectory reconstruction and camera synchronization.Present methods typically address only one of these sub-problems individually.This paper proposes a 3D trajectory reconstruction method for point targets based on asynchronous cameras,simultaneously solving both sub-problems.Firstly,we extend the trajectory intersection method to asynchronous cameras to resolve the limitation of traditional triangulation that requires camera synchronization.Secondly,we develop models for camera temporal information and target motion,based on imaging mechanisms and target dynamics characteristics.The parameters are optimized simultaneously to achieve trajectory reconstruction without accurate time parameters.Thirdly,we optimize the camera rotations alongside the camera time information and target motion parameters,using tighter and more continuous constraints on moving points.The reconstruction accuracy is significantly improved,especially when the camera rotations are inaccurate.Finally,the simulated and real-world experimental results demonstrate the feasibility and accuracy of the proposed method.The real-world results indicate that the proposed algorithm achieved a localization error of 112.95 m at an observation distance range of 15-20 km.
基金the Deanship of Research and Graduate Studies at King Khalid University for funding this work through Large Research Project under grant number RGP2/308/46。
文摘Fins are extensively utilized in heat exchangers and various industrial applications as they are lightweight and can benefit in various systems,including electronic cooling devices and automotive components,owing to their adaptable design.Furthermore,spine fins are introduced to improve performance in applications such as automotive radiators.They can be shaped in different ways and constructed from a collection of materials.Inspired by this,the present model examines the effects of internal heat generation and radiation-convection on the thermal distribution in a wetted convex-shaped spine fin.Using dimensionless terms,the proposed fin model involving a governing nonlinear ordinary differential equation(ODE)is transformed into a dimensionless form.The study uses the operational matrix with the Charlier polynomial collocation method(OMCCM)to ensure precise and computationally efficient numerical solutions for the dimensionless equation.In order to aid in the analysis of thermal performance,the importance of major parameters on the temperature profile is graphically illustrated.The main outcome of the study reveals that as the radiation-conductive,wet,and convective-conductive parameters increase,the heat transfer rate progressively improves.Conversely,the ambient temperature and internal heat generation parameters show an inverse relationship.
基金supported by the National Natural Science Foundation of China(No.12271527)。
文摘In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in this paper,we prove that rooted products of some trees preserve real-rootedness of independence polynomials.In particular,we can obtain that their independence polynomials are unimodal and log-concave.
基金supported by the National Natural Science Foundation of China(61703286,62394342,61890924,61991404)。
文摘This paper investigates set-valued state estimation of nonlinear systems with unknown-but-bounded(UBB)noises based on constrained polynomial zonotopes which is utilized to characterize non-convex sets.First,properties of constrained polynomial zonotopes are provided and the order reduction method is given to reduce the computational complexity.Then,the corresponding improved prediction-update algorithm is proposed so that it can be adapted to non-convex sets.Based on generalized intersection,the utilization of set-based estimation for attack detection is analyzed.Finally,an example is given to show the efficiency of our results.
基金Supported by the National Natural Science Foundation of China(Grant No.12201254)。
文摘In this paper, two new efficient fully nonconforming polynomial finite element methods on arbitrary convex quadrilaterals are constructed to solve the Brinkman problem. Both elements have 12 local degrees of freedom and are uniformly first-order convergent. For the first element, we carefully design a shape function space of only degree four, which is convenient for practical computation. Meanwhile, the velocity solution obtained by our second element has O(h^(2)) convergence order in the case of Darcy limit. These new elements can be regarded as modifications of a known element to effectively improve the computational efficiency, only the shape function space is properly changed. We verify our theoretical findings by numerical examples.
基金supported by ZTE Industry-University-Institute Cooperation Funds under Grant No.HC-CN-20220722010。
文摘This paper proposes a concurrent neural network model to mitigate non-linear distortion in power amplifiers using a basis function generation approach.The model is designed using polynomial expansion and comprises a feedforward neural network(FNN)and a convolutional neural network(CNN).The proposed model takes the basic elements that form the bases as input,defined by the generalized memory polynomial(GMP)and dynamic deviation reduction(DDR)models.The FNN generates the basis function and its output represents the basis values,while the CNN generates weights for the corresponding bases.Through the concurrent training of FNN and CNN,the hidden layer coefficients are updated,and the complex multiplication of their outputs yields the trained in-phase/quadrature(I/Q)signals.The proposed model was trained and tested using 300 MHz and 400 MHz broadband data in an orthogonal frequency division multiplexing(OFDM)communication system.The results show that the model achieves an adjacent channel power ratio(ACPR)of less than-48 d B within a 100 MHz integral bandwidth for both the training and test datasets.
