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A new dynamic subgrid-scale model using artificial neural network for compressible flow
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作者 Han Qi Xinliang Li +1 位作者 Ning Luo Changping Yu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2022年第4期267-274,共8页
The subgrid-scale(SGS)kinetic energy has been used to predict the SGS stress in compressible flow and it was resolved through the SGS kinetic energy transport equation in past studies.In this paper,a new SGS eddy-visc... The subgrid-scale(SGS)kinetic energy has been used to predict the SGS stress in compressible flow and it was resolved through the SGS kinetic energy transport equation in past studies.In this paper,a new SGS eddy-viscosity model is proposed using artificial neural network to obtain the SGS kinetic energy precisely,instead of using the SGS kinetic energy equation.Using the infinite series expansion and reserving the first term of the expanded term,we obtain an approximated SGS kinetic energy,which has a high correlation with the real SGS kinetic energy.Then,the coefficient of the modelled SGS kinetic energy is resolved by the artificial neural network and the modelled SGS kinetic energy is more accurate through this method compared to the SGS kinetic energy obtained from the SGS kinetic energy equation.The coefficients of the SGS stress and SGS heat flux terms are determined by the dynamic procedure.The new model is tested in the compressible turbulent channel flow.From the a posterior tests,we know that the new model can precisely predict the mean velocity,the Reynolds stress,the mean temperature and turbulence intensities,etc. 展开更多
关键词 subgrid-scale kinetic energy Eddy-viscosity model Compressible flow
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Dynamic modeling and analysis of an in-space cable-driven manipulator for on-orbit servicing
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作者 Yiya WANG Bo ZHANG Minghe SHAN 《Chinese Journal of Aeronautics》 2026年第2期609-625,共17页
In-space cable-driven manipulators exhibit several advantages,such as a large range of motion,high dexterity,and lightweight structure.However,kinematic and dynamic analysis play an essential role in designing a cable... In-space cable-driven manipulators exhibit several advantages,such as a large range of motion,high dexterity,and lightweight structure.However,kinematic and dynamic analysis play an essential role in designing a cable-driven manipulator.In this paper,the kinematic analysis of a type of cable-driven manipulator is performed,and a motion planning scheme is conducted to actuate this manipulator.Moreover,a flexible multi-body dynamic model of a cable-driven manipulator considering the frictional contact between the cables and pulleys is established.To describe properties such as flexibility,vibration,and variable length of the cable,this paper utilizes reducedorder beam elements of the Absolute Nodal Coordinates Formulation(ANCF)in Arbitrary Lagrangian Eulerian(ALE)framework.Additionally,a virtual element is introduced to model the contact segment in the cable-pulley system.A tension decay factor is employed to account for the friction in the contact segment.To validate the proposed method,a semi-analytical model based on D'Alembert's principle is established.Cross-verification is performed to validate the accuracy of both models.The model is further applied to simulate the rotation of the cable-driven manipulator with different structural parameters and frictional factors.The results from the analyses provide valuable guidance for the design and motion control of the in-space cable-driven manipulator.Finally,a prototype of a single module is manufactured and tested.Ground experiments are carried out to verify the kinematic and dynamic models. 展开更多
关键词 Cable-driven manipulator dynamic models Cable-pulley system Arbitrary Lagrangian Eulerian(ALE)formulation Frictional contact modeling
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THE DYNAMICAL BEHAVIOR OF AN ALMOST PERIODIC SVEIR WARNING MODEL IN A PATCHY ENVIRONMENT
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作者 Binguo WANG Xiaomei MA Yashi WANG 《Acta Mathematica Scientia》 2026年第1期427-458,共32页
The outbreak of infectious diseases is the result of a combination of various factors,including season,the movement of individuals,non-pharmaceutical interventions(NPIs)and the effectiveness and availability of vaccin... The outbreak of infectious diseases is the result of a combination of various factors,including season,the movement of individuals,non-pharmaceutical interventions(NPIs)and the effectiveness and availability of vaccines.Taking these key elements into consideration,an almost periodic SVEIR warning model in the patch environment is here proposed.First,in terms of reproduction numbers,our results imply that if the effective reproduction numbers are R_(e)<1,then the disease dies out;if R_(e)>1,then the disease spreads and leads to local outbreaks.Second,the relationships between R_(e)and C_(s1),C_(a1)(see Section 2)are given by numerical simulations.The numerical results show that even if all people are vaccinated,NPIs are still needed because of the potentially low efficacy of vaccines.Furthermore,the numerical results suggest that NPIs and the strengthening of the effective rate of vaccination are essential in order to achieve herd immunity.Theories involving this model effectively explain the transmission mechanism of most infectious diseases,and provide a valuable theoretical basis for analyzing new infectious diseases in the future.Moreover,this model is helpful for the prevention and control of infectious diseases and the formulation of public health safety policies. 展开更多
关键词 SVEIR model almost periodicity reproduction ratio skew-product semiflow threshold dynamics
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Face-Pedestrian Joint Feature Modeling with Cross-Category Dynamic Matching for Occlusion-Robust Multi-Object Tracking
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作者 Qin Hu Hongshan Kong 《Computers, Materials & Continua》 2026年第1期870-900,共31页
To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework ba... To address the issues of frequent identity switches(IDs)and degraded identification accuracy in multi object tracking(MOT)under complex occlusion scenarios,this study proposes an occlusion-robust tracking framework based on face-pedestrian joint feature modeling.By constructing a joint tracking model centered on“intra-class independent tracking+cross-category dynamic binding”,designing a multi-modal matching metric with spatio-temporal and appearance constraints,and innovatively introducing a cross-category feature mutual verification mechanism and a dual matching strategy,this work effectively resolves performance degradation in traditional single-category tracking methods caused by short-term occlusion,cross-camera tracking,and crowded environments.Experiments on the Chokepoint_Face_Pedestrian_Track test set demonstrate that in complex scenes,the proposed method improves Face-Pedestrian Matching F1 area under the curve(F1 AUC)by approximately 4 to 43 percentage points compared to several traditional methods.The joint tracking model achieves overall performance metrics of IDF1:85.1825%and MOTA:86.5956%,representing improvements of 0.91 and 0.06 percentage points,respectively,over the baseline model.Ablation studies confirm the effectiveness of key modules such as the Intersection over Area(IoA)/Intersection over Union(IoU)joint metric and dynamic threshold adjustment,validating the significant role of the cross-category identity matching mechanism in enhancing tracking stability.Our_model shows a 16.7%frame per second(FPS)drop vs.fairness of detection and re-identification in multiple object tracking(FairMOT),with its cross-category binding module adding aboute 10%overhead,yet maintains near-real-time performance for essential face-pedestrian tracking at small resolutions. 展开更多
关键词 Cross-category dynamic binding joint feature modeling face-pedestrian association multi object tracking occlusion robustness
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Modeling decadal snow and ice dynamics and their hydrological impacts in the Balkhash Lake Basin,Central Asia
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作者 GAN Guojing WU Jinglu +2 位作者 YANG Ruibiao GAO Yanchun SHEN Beibei 《Journal of Arid Land》 2026年第4期547-567,共21页
The Balkhash Lake Basin(BLB),a vital Central Asian watershed,faces hydrological uncertainty under climate warming.This study integrated multi-source remote sensing data(Sentinel-1 snow depth,Randolph Glacier Inventory... The Balkhash Lake Basin(BLB),a vital Central Asian watershed,faces hydrological uncertainty under climate warming.This study integrated multi-source remote sensing data(Sentinel-1 snow depth,Randolph Glacier Inventory(RGI)v.7.0 glacier inventory,and Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)mass balance)with a degree-day model to reconstruct decadal snow and ice dynamics across 13 sub-basins and analyzed their hydrological impacts from 1950 to 2014.The results showed that:(1)while flows from the downstream river of the BLB decreased from 1950 to 1982 due to land surface changes,runoff increased significantly after 1982 in the Ili River(18.0%)and moderately increased in most rivers in the east(1.3%–8.3%),driven by increased precipitation and glacier melt.Runoff in the Ayaguz catchment(no glaciers with the highest climate warming)declined(10.5%);(2)climate warming reduced precipitation falling as snow caused snow melt water to decline(0.03–0.22 mm/a)across the BLB,leading to downward shifts in runoff and runoff coefficient,especially in the rivers in the east.However,snow melt during April–June positively correlated with runoff coefficient,contributing to an upward shift in the Ili River Basin;and(3)meltwater from glacierized areas(<5.0%of basin area)contributed to 14.3%of total ablation water.Net glacier melt provided substantial excess flows(11.6 m3/s in the Ili River and<1.0 m3/s in the rivers in the east),generally counterbalancing the negative effect of rising potential evaporation at decadal scales and positively correlating with the runoff coefficient.Therefore,water stress in the BLB may be more severe in the future due to the accelerating glacier melt after the abrupt increase in air temperature in 2000,the continuing decline in snow melt,and the significant inter-annual variations in precipitation. 展开更多
关键词 runoff trend snow and ice dynamics degree-day model remote sensing Balkhash Lake Basin
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A Deterministic and Stochastic Fractional-Order Model for Computer Virus Propagation with Caputo-Fabrizio Derivative:Analysis,Numerics,and Dynamics
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作者 Najat Almutairi Mohammed Messaoudi +1 位作者 Faisal Muteb K.Almalki Sayed Saber 《Computer Modeling in Engineering & Sciences》 2026年第3期806-843,共38页
This paper introduces a novel fractional-order model based on the Caputo-Fabrizio(CF)derivative for analyzing computer virus propagation in networked environments.The model partitions the computer population into four... This paper introduces a novel fractional-order model based on the Caputo-Fabrizio(CF)derivative for analyzing computer virus propagation in networked environments.The model partitions the computer population into four compartments:susceptible,latently infected,breaking-out,and antivirus-capable systems.By employing the CF derivative—which uses a nonsingular exponential kernel—the framework effectively captures memory-dependent and nonlocal characteristics intrinsic to cyber systems,aspects inadequately represented by traditional integer-order models.Under Lipschitz continuity and boundedness assumptions,the existence and uniqueness of solutions are rigorously established via fixed-point theory.We develop a tailored two-step Adams-Bashforth numerical scheme for the CF framework and prove its second-order accuracy.Extensive numerical simulations across various fractional orders reveal that memory effects significantly influence virus transmission and control dynamics;smaller fractional orders produce more pronounced memory effects,delaying both infection spread and antivirus activation.Further theoretical analysis,including Hyers-Ulam stability and sensitivity assessments,reinforces the model’s robustness and identifies key parameters governing virus dynamics.The study also extends the framework to incorporate stochastic effects through a stochastic CF formulation.These results underscore fractional-order modeling as a powerful analytical tool for developing robust and effective cybersecurity strategies. 展开更多
关键词 Caputo-Fabrizio derivative fractional-order computer virus model stochastic fractional dynamics Adams-Bashforth scheme Hyers-Ulam stability sensitivity analysis cyber-epidemiology memory effects nonsingular kernel
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Dynamic characterization of pathological and functional deterioration in a mouse model of optic neuritis related to neuromyelitis optica spectrum disorder
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作者 Xiayin Yang Shi-Qi Yao +1 位作者 Henry Ho-Lung Chan Shaoying Tan 《Neural Regeneration Research》 2026年第8期3870-3880,共11页
Neuromyelitis optica spectrum disorder-related optic neuritis involves various cellular responses to inflammation and degeneration.In most patients,the primary mechanism underlying neuromyelitis optica spectrum disord... Neuromyelitis optica spectrum disorder-related optic neuritis involves various cellular responses to inflammation and degeneration.In most patients,the primary mechanism underlying neuromyelitis optica spectrum disorder-related optic neuritis is the interaction of aquaporin-4 antibodies with the aquaporin-4 protein present on astrocytes within posterior optic nerve.This binding subsequently initiates a cascade of events leading to secondary demyelination of the optic nerve,ultimately culminating in optic nerve degeneration.Earlier studies on this disorder primarily used systemic-induced animal models,which often require prior activation of a systemic immune response.This can result in primary demyelination of the optic nerve,complicating the interpretation of experimental results.Such methodologies hinder the ability to isolate immune responses triggered by specific antibodies.Additionally,the lack of a detailed profile of disease progression over time limits our capacity to identify potential intervention windows.Therefore,constructing a targeted optic neuritis animal model induced by specific antibodies and elucidate the disease progression arecrucial for exploring the mechanisms underlying neuromyelitis optica spectrum disorder-related optic neuritis.In this study,specific antibodies against aquaporin-4 were precisely injected into the retrobulbar optic nerve of mice to induce a targeted inflammatory response in the posterior optic nerve,resulting in a more representative mouse model of neuromyelitis optica spectrum disorder-related optic neuritis than current models.The progression of the disease was then dynamically observed from both histological and functional perspectives over the course of 1 month following the induction of inflammation.By the first week,astrocytes were damaged,as evidenced by the loss of aquaporin-4 and glial fibrillary acidic protein,the activation of microglia,and the upregulation of microglia-related cytokines,including tumor necrosis factor,interleukin-6,interleukin-1β,C-X-C motif ligand 10,and brain-derived neurotrophic factor.Starting from the second week,there were signs of optic nerve demyelination and significant damage to axonal fibers and retinal ganglion cell bodies.Visual-evoked potentials and dark adaptation threshold responses in electroretinogram both indicated dysfunction in the visual pathway and retina,while optical coherence tomography revealed thinning of the retinal nerve fiber layer in live mice.In summary,in this study we conducted a dynamic exploration of the occurrence and progression of neuromyelitis optica spectrum disorder-related optic neuritis triggered by specific antibodies.Our results show pathological changes at various stages and correlate histological and molecular alterations with in vivo structural and functional deterioration.The findings from this study lay an important foundation for further research on neuromyelitis optica spectrum disorder-related optic neuritis. 展开更多
关键词 animal model aquaporin-4 immunoglobulin G dynamic profile ELECTRORETINOGRAM functional deterioration in vivo retinal structural scan neuromyelitis optica spectrum disorder-related optic neuritis optic neuritis pathology visual-evoked potential
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An improved dynamic subgrid-scale model and its application to large eddy simulation of rotating channel flows 被引量:2
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作者 LIU Nansheng LU Xiyun ZHUANG Lixian 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2004年第4期463-476,共14页
A new dynamic subgrid-scale (SGS) model, which is proved to satisfy the principle of asymptotic material frame indifference (AMFI) for rotating turbulence, is proposed based on physical and mathematical analysis. Comp... A new dynamic subgrid-scale (SGS) model, which is proved to satisfy the principle of asymptotic material frame indifference (AMFI) for rotating turbulence, is proposed based on physical and mathematical analysis. Comparison with direct numerical simulation (DNS) results verifies that the new SGS model is effective for large eddy simulation (LES) on rotating turbulent flow. The SGS model is then applied to the LES of the spanwise rotating turbulent channel flow to investigate the rotation effect on turbulence characteristics, budget terms in the transport equations of resolved Reynolds stresses, and flow structures near the wall regions of the rotating channel. 展开更多
关键词 large EDDY simulation (LES) dynamic subgrid-scale (SGS) model ROTATING turbulent channel flow asymptotic material frame INDIFFERENCE (AMFI).
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A SECOND-ORDER DYNAMIC SUBGRID-SCALE STRESS MODEL
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作者 龚洪瑞 陈十一 +1 位作者 何国威 曹念铮 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第2期165-172,共8页
A second-order dynamic model based on the general relation between the subgrid-scale stress and the velocity gradient tensors was proposed. A priori test of the second-order model was made using moderate resolution di... A second-order dynamic model based on the general relation between the subgrid-scale stress and the velocity gradient tensors was proposed. A priori test of the second-order model was made using moderate resolution direct numerical simulation date at high Reynolds number ( Taylor microscale Reynolds number R-lambda = 102 similar to 216) for homogeneous, isotropic forced flow, decaying flow, and homogeneous rotating flow. Numerical testing shows that the second-order dynamic model significantly improves the correlation coefficient when compared to the first-order dynamic models. 展开更多
关键词 turbulent now dynamic model subgrid-scale stress model Smagorinsky model
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An improved dynamic subgrid-scale model and its application to large eddy simulation of stratified channel flows
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作者 仲峰泉 庄礼贤 +1 位作者 刘难生 陆夕云 《Science China Mathematics》 SCIE 2002年第7期888-899,共12页
In the present paper, a new dynamic subgrid-scale (SGS) model of turbulent stress and heat flux for stratified shear flow is proposed. Based on our calculated results of stratified channel flow, the dynamic subgrid-sc... In the present paper, a new dynamic subgrid-scale (SGS) model of turbulent stress and heat flux for stratified shear flow is proposed. Based on our calculated results of stratified channel flow, the dynamic subgrid-scale model developed in this paper is shown to be effective for large eddy simulation (LES) of stratified turbulent shear flows. The new SGS model is then applied to the LES of the stratified turbulent channel flow to investigate the coupled shear and buoyancy effects on the behavior of turbulent statistics, turbulent heat transfer and flow structures at different Richardson numbers. 展开更多
关键词 large EDDY simulation (LES) dynamic subgrid-scale (SGS) model STRATIFIED shear turbulence turbulent channel flow.
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A dynamic subgrid-scale model for the large eddy simulation of stratified flow
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作者 刘宁宇 陆夕云 庄礼贤 《Science China Mathematics》 SCIE 2000年第4期391-399,共9页
A new dynamic subgrid-scale (SGS) model, including subgrid turbulent stress and heat flux models for stratified shear flow is proposed by using Yoshizawa’ s eddy viscosity model as a base model. Based on our calculat... A new dynamic subgrid-scale (SGS) model, including subgrid turbulent stress and heat flux models for stratified shear flow is proposed by using Yoshizawa’ s eddy viscosity model as a base model. Based on our calculated results, the dynamic subgrid-scale model developed here is effective for the large eddy simulation (LES) of stratified turbulent channel flows. The new SGS model is then applied to the large eddy simulation of stratified turbulent channel flow under gravity to investigate the coupled shear and buoyancy effects on the near-wall turbulent statistics and the turbulent heat transfer at different Richardson numbers. The critical Richardson number predicted by the present calculation is in good agreement with the value of theoretical analysis. 展开更多
关键词 large EDDY simulation (LES) subgrid-scale model (SGS) STRATIFIED TURBULENCE heat transfer.
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Dynamic response of RC columns under off-central explosions:Experimental,theoretical studies and neural network prediction
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作者 Hao Wang Xiangyu Li +2 位作者 Yong Peng Zhandong Tian Fangyun Lu 《Defence Technology(防务技术)》 2026年第2期314-336,共23页
Reinforced concrete(RC)columns are often subjected to off-central explosion due to the uncertainty of blast locations.However,few studies have focused on the dynamic response of RC columns under offcentral explosions.... Reinforced concrete(RC)columns are often subjected to off-central explosion due to the uncertainty of blast locations.However,few studies have focused on the dynamic response of RC columns under offcentral explosions.A field blast experiment was conducted under close-in explosion with varying detonation offset distances(0 m,0.5 m,and 1 m),the overpressure load and dynamic responses of the full-scale RC columns were measured.Compared with the centrally detonated condition,a relative offset distance of 1.67 decreases the maximum and residual deflections of the RC column by 16.8%and 21.4%,respectively,while increasing the maximum and residual support rotations by 24.7%and 17.8%.Based on the experimental results,a theoretical model was proposed that considers the detonation location and charge mass,boundary conditions,axial compression ratio and material properties.The theoretical model exhibited good agreement with the experimental results,with prediction errors below 10%for both maximum and residual deflection.The effects of parameters were analyzed,and it indicated that an increase in offset distance results in decreased maximum and residual deflections but an increased support angle,thereby exacerbating damage.Higher axial load ratio,span-depth ratio,and longitudinal reinforcement ratio reduce both deflections and support angle.Additionally,a rapid method to predict the maximum and residual deflection of RC columns under off-central blast loading was also proposed based on the Generalized Regression Neural Network(GRNN).Eleven features which related to the RC column properties and the blast characteristics were used in the training process of GRNN,and accurate predictions were achieved with prediction errors within 20%.This study fills the gap in predicting the dynamic response of RC columns under off-central explosion,providing valuable references for blast-resistant design. 展开更多
关键词 dynamic responses RC columns Off-central explosions Theoretical model GRNN
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Development and application of rock rheological constitutive model considering dynamic stress field and seepage field 被引量:3
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作者 Yian Chen Guangming Zhao +2 位作者 Wensong Xu Shoujian Peng Jiang Xu 《International Journal of Mining Science and Technology》 2025年第3期467-482,共16页
The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is great... The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is greater than that under creep conditions,indicating that the dynamic stress field significantly influences the rheological behaviours of sandstone.Following the rheological tests,the number of small pores in the sandstone decreased,while the number of medium-sized pores increased,forming new seepage channels.The high initial rheological stress accelerated fracture compression and the closure of seepage channels,resulting in reduction in the permeability of sandstone.Based on the principles of generalized rheology and the experimental findings,a novel rock rheological constitutive model incorporating both the dynamic stress field and seepage properties has been developed.Numerical simulations of surrounding rock deformation in geotechnical engineering were carried out using a secondary development version of this model,which confirmed the applicability of the generalized rheological numerical simulation method.These results provide theoretical support for the long-term stability evaluation of engineering rock masses and for predicting the deformation of surrounding rock. 展开更多
关键词 Generalized rheological test Seepage-stress coupling Seepage properties dynamic stress field Rheological constitutive model
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Study on Construction of a New Business Education Ecology Driven by Government-industry-academia-research Synergy and Dual-cycle Dynamic Iteration
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作者 QIU Renyi 《International Journal of Plant Engineering and Management》 2026年第1期1-19,共19页
In the era of digital economy,business education lags behind the rapid iteration of industrial technology,which has become the core contradiction hindering industrial development.In order to solve the key problem of t... In the era of digital economy,business education lags behind the rapid iteration of industrial technology,which has become the core contradiction hindering industrial development.In order to solve the key problem of the disconnection between education supply and industrial demand,this paper proposes the“government,industry,academia,research and dynamic iteration”education ecological framework based on the ecological niche theory and the collaborative innovation theory,and adopts the combination of model construction and case study verification research method.The framework designs a four-dimensional collaborative nurturing mechanism that includes the linkage of multiple subjects and a double-cycle dynamic adjustment model based on feedback optimization,and constructs three major systems of technical support,resource integration and quality assurance.The research effectively breaks through the traditional linear cultivation paradigm,and the validation shows that the framework can significantly improve the matching degree and dynamic adaptability of talent cultivation and industrial demand.This paper not only provides a systematic theoretical model for the construction of a new business education system adapted to the needs of the digital economy,but also contributes an operable practical path,which is of great theoretical value and practical reference significance for promoting the digital transformation of business education. 展开更多
关键词 government-industry-academia-research collaboration dynamic iterative mechanism double-loop model new business education ecology
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Quality related fault detection based on dynamic-inner convolutional autoencoder and partial least squares and its application to ironmaking process
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作者 Ping Wu Yuxuan Ni +4 位作者 Huaimin Wang Xuguang Hu Zhenquan Wu Jian Jiang Yaowu Hu 《Chinese Journal of Chemical Engineering》 2026年第1期267-276,共10页
Partial least squares (PLS) model maximizes the covariance between process variables and quality variables,making it widely used in quality-related fault detection.However,traditional PLS methods focus primarily on li... Partial least squares (PLS) model maximizes the covariance between process variables and quality variables,making it widely used in quality-related fault detection.However,traditional PLS methods focus primarily on linear processes,leading to poor performance in dynamic nonlinear processes.In this paper,a novel quality-related fault detection method,named DiCAE-PLS,is developed by combining dynamic-inner convolutional autoencoder with PLS.In the proposed DiCAE-PLS method,latent features are first extracted through dynamic-inner convolutional autoencoder (DiCAE) to capture process dynamics and nonlinearity from process variables.Then,a PLS model is established to build the relationship between the extracted latent features and the final product quality.To detect quality-related faults,Hotelling's T^(2) statistic is employed.The developed quality-related fault detection is applied to the widely used industrial benchmark of the Tennessee. 展开更多
关键词 Partial least squares dynamic-inner convolutional autoencoder Quality-related fault detection Neural networks Safety dynamic modeling
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Stress analysis of crack characteristic of anthracite under dynamic loading
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作者 Yun Bai Feng Gao +3 位作者 Ning Luo Zhizhen Zhang Yue Niu Shanjie Su 《Deep Underground Science and Engineering》 2026年第1期56-65,共10页
The coal dynamic characteristic stress identification under dynamic load is important for guiding underground mineral mining and predicting underground dynamic disasters.In this article,the dynamic compression test of... The coal dynamic characteristic stress identification under dynamic load is important for guiding underground mineral mining and predicting underground dynamic disasters.In this article,the dynamic compression test of anthracite under five strain rates is carried out,the evolution law of three kinds of crack characteristic stress is analyzed,and a prediction model of the crack characteristic stress threshold considering the strain rate effect is established.Then,the rationality of crack characteristic stress under dynamic loading is discussed from the damage evolution standpoint,and the crack extension response mechanism during dynamic compression of anthracite is discussed.The result shows that the crack characteristic stress threshold is significantly influenced by the strain rate.The three characteristic stress thresholds are positively correlated with the strain rate,but the ratios to the crest stress gradually decrease.The increase in the strain rate strongly contributes to the crack extension behavior of anthracite.In the crack unstable extension phase,because of the increase of the strain rate,anthracite shows more energy dissipation under the same deformation in association with the stress concentration effect and the dynamic strength enhancement effect.The crack propagation rate is increased,the crack propagation path of the section is more complex,and more severe damage occurs before the dynamic failure of anthracite,which leads to even more severe damage. 展开更多
关键词 crack characteristic stress threshold damage evolution prediction model strain rate effect underground dynamic disasters
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Virtual histology imaging of lymph nodes via dynamic full-field optical coherence tomography and deep learning to differentiate metastasis
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作者 Shuwei Zhang Houpu Yang +8 位作者 Yiyin Zhang Xiaoxian Li Jin Zhao Yuanyuan Zhang Ping Xue Hua Kang Hongchuan Jiang Wenhui Ren Shu Wang 《Cancer Biology & Medicine》 2026年第3期418-429,共12页
Objective:The current pathological diagnosis of lymph node metastasis is time-consuming,labor-intensive,and dependent on sectioning of paraffin blocks.Herein,in a prospective cohort of patients with breast cancer,we v... Objective:The current pathological diagnosis of lymph node metastasis is time-consuming,labor-intensive,and dependent on sectioning of paraffin blocks.Herein,in a prospective cohort of patients with breast cancer,we validated dynamic full-field optical coherence tomography(D-FFOCT),a virtual pathology tool integrating deep learning for nodal metastasis detection,and offering rapid and label-free histologic approximations of fresh tissues.Methods:In a prospective dual-center cohort of 155 patients with breast cancer,747 freshly bisected lymph node slides were obtained via D-FFOCT.Surgeons interpreted each slide with histopathology as the gold standard.A deep learning model was trained on 28,911 patches(corresponding to 590 slides)and tested on 7,736 patches(corresponding to 157 slides).The results were mapped to the slide level for potential intraoperative evaluation.Results:D-FFOCT strongly correlated with hematoxylin and eosin(H&E)-stained histological images.Surgeons achieved 97.10%specificity in nodal diagnosis with D-FFOCT.The performance of the artificial intelligence(AI)model was not inferior to that of human experts and had a sensitivity/specificity of 87.88%/91.94%and an area under the receiver operating characteristic curve of 0.899 at the slide level.The human–AI collaborative system reduced labor requirements by 75%and increased the specificity by 6.5%,to 98.39%.Conclusions:D-FFOCT has excellent potential as a tool for assessing lymph node metastatic status without tissue preparation or consumption.The integration of D-FFOCT with deep learning decreases labor demands and maintains high accuracy,thereby enabling streamlined nodal prediction independent of routine pathology procedures. 展开更多
关键词 Breast cancer dynamic full field optical coherence tomography lymph nodes AI model metastatic status
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Smart cities,smart systems:A comprehensive review of system dynamics model applications in urban studies in the big data era 被引量:2
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作者 Gift Fabolude Charles Knoble +1 位作者 Anvy Vu Danlin Yu 《Geography and Sustainability》 2025年第1期25-36,共12页
This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models ... This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models offer insights, they fall short in presenting a holistic view of complex urban challenges. System dynamics (SD) models that are often utilized to provide holistic, systematic understanding of a research subject, like the urban system, emerge as valuable tools, but data scarcity and theoretical inadequacy pose challenges. The research reviews relevant papers on recent SD model applications in urban sustainability since 2018, categorizing them based on nine key indicators. Among the reviewed papers, data limitations and model assumptions were identified as ma jor challenges in applying SD models to urban sustainability. This led to exploring the transformative potential of big data analytics, a rare approach in this field as identified by this study, to enhance SD models’ empirical foundation. Integrating big data could provide data-driven calibration, potentially improving predictive accuracy and reducing reliance on simplified assumptions. The paper concludes by advocating for new approaches that reduce assumptions and promote real-time applicable models, contributing to a comprehensive understanding of urban sustainability through the synergy of big data and SD models. 展开更多
关键词 Urban sustainability Smart cities System dynamics models Big data analytics Urban system complexity Data-driven urbanism
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Evaluations of large language models in computational fluid dynamics:Leveraging,learning and creating knowledge 被引量:1
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作者 Long Wang Lei Zhang Guowei He 《Theoretical & Applied Mechanics Letters》 2025年第3期207-218,共12页
This paper investigates the capabilities of large language models(LLMs)to leverage,learn and create knowledge in solving computational fluid dynamics(CFD)problems through three categories of baseline problems.These ca... This paper investigates the capabilities of large language models(LLMs)to leverage,learn and create knowledge in solving computational fluid dynamics(CFD)problems through three categories of baseline problems.These categories include(1)conventional CFD problems that can be solved using existing numerical methods in LLMs,such as lid-driven cavity flow and the Sod shock tube problem;(2)problems that require new numerical methods beyond those available in LLMs,such as the recently developed Chien-physics-informed neural networks for singularly perturbed convection-diffusion equations;and(3)problems that cannot be solved using existing numerical methods in LLMs,such as the ill-conditioned Hilbert linear algebraic systems.The evaluations indicate that reasoning LLMs overall outperform non-reasoning models in four test cases.Reasoning LLMs show excellent performance for CFD problems according to the tailored prompts,but their current capability in autonomous knowledge exploration and creation needs to be enhanced. 展开更多
关键词 Large language models Computational fluid dynamics Machine learning
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Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions 被引量:1
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作者 Chentong GAO Huiyu SUN +1 位作者 Jianping GU W.M.HUANG 《Applied Mathematics and Mechanics(English Edition)》 2025年第1期123-138,共16页
Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade compone... Currently,there are a limited number of dynamic models available for braided composite plates with large overall motions,despite the incorporation of three-dimensional(3D)braided composites into rotating blade components.In this paper,a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established.Based on Kirchhoff's plate assumptions,the displacement variables of the plate are expressed.By incorporating the braiding directions into the constitutive equation of the braided composites,the dynamic model of the plate considering braiding directions is obtained.The effects of the speeds,braiding directions,and braided angles on the responses of the plate with fixed-axis rotation and translational motion,respectively,are investigated.This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions.It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications. 展开更多
关键词 three-dimensional(3D)braided composite braiding direction composite thin plate large overall motion dynamic model
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