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Low-Complexity Hardware Architecture for Batch Normalization of CNN Training Accelerator
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作者 Go-Eun Woo Sang-Bo Park +2 位作者 Gi-Tae Park Muhammad Junaid Hyung-Won Kim 《Computers, Materials & Continua》 2025年第8期3241-3257,共17页
On-device Artificial Intelligence(AI)accelerators capable of not only inference but also training neural network models are in increasing demand in the industrial AI field,where frequent retraining is crucial due to f... On-device Artificial Intelligence(AI)accelerators capable of not only inference but also training neural network models are in increasing demand in the industrial AI field,where frequent retraining is crucial due to frequent production changes.Batch normalization(BN)is fundamental to training convolutional neural networks(CNNs),but its implementation in compact accelerator chips remains challenging due to computational complexity,particularly in calculating statistical parameters and gradients across mini-batches.Existing accelerator architectures either compromise the training accuracy of CNNs through approximations or require substantial computational resources,limiting their practical deployment.We present a hardware-optimized BN accelerator that maintains training accuracy while significantly reducing computational overhead through three novel techniques:(1)resourcesharing for efficient resource utilization across forward and backward passes,(2)interleaved buffering for reduced dynamic random-access memory(DRAM)access latencies,and(3)zero-skipping for minimal gradient computation.Implemented on a VCU118 Field Programmable Gate Array(FPGA)on 100 MHz and validated using You Only Look Once version 2-tiny(YOLOv2-tiny)on the PASCALVisualObjectClasses(VOC)dataset,our normalization accelerator achieves a 72%reduction in processing time and 83%lower power consumption compared to a 2.4 GHz Intel Central Processing Unit(CPU)software normalization implementation,while maintaining accuracy(0.51%mean Average Precision(mAP)drop at floating-point 32 bits(FP32),1.35%at brain floating-point 16 bits(bfloat16)).When integrated into a neural processing unit(NPU),the design demonstrates 63%and 97%performance improvements over AMD CPU and Reduced Instruction Set Computing-V(RISC-V)implementations,respectively.These results confirm that our proposed BN hardware design enables efficient,high-accuracy,and power-saving on-device training for modern CNNs.Our results demonstrate that efficient hardware implementation of standard batch normalization is achievable without sacrificing accuracy,enabling practical on-device CNN training with significantly reduced computational and power requirements. 展开更多
关键词 Convolutional neural network normalIZATION batch normalization deep learning TRAINING HARDWARE
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Analytic approximation of periodic orbits with renormalization group
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作者 Haoyi Huang Tianyi Wang +1 位作者 Pengfei Guo Yueheng Lan 《Communications in Theoretical Physics》 2025年第8期11-24,共14页
Renormalization group analysis has been proposed to eliminate secular terms in perturbation solutions of differential equations and thus expand the domain of their validity.Here we extend the method to treat periodic ... Renormalization group analysis has been proposed to eliminate secular terms in perturbation solutions of differential equations and thus expand the domain of their validity.Here we extend the method to treat periodic orbits or limit cycles.Interesting normal forms could be derived through a generalization of the concept'resonance',which offers nontrivial analytic approximations.Compared with traditional techniques such as multi-scale methods,the current scheme proceeds in a very straightforward and simple way,delivering not only the period and the amplitude but also the transient path to limit cycles.The method is demonstrated with several examples including the Duffing oscillator,van der Pol equation and Lorenz equation.The obtained solutions match well with numerical results and with those derived by traditional analytic methods. 展开更多
关键词 nonlinear dynamics cycles renormalization group analytic solution normal forms
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Effects of feature selection and normalization on network intrusion detection 被引量:1
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作者 Mubarak Albarka Umar Zhanfang Chen +1 位作者 Khaled Shuaib Yan Liu 《Data Science and Management》 2025年第1期23-39,共17页
The rapid rise of cyberattacks and the gradual failure of traditional defense systems and approaches led to using artificial intelligence(AI)techniques(such as machine learning(ML)and deep learning(DL))to build more e... The rapid rise of cyberattacks and the gradual failure of traditional defense systems and approaches led to using artificial intelligence(AI)techniques(such as machine learning(ML)and deep learning(DL))to build more efficient and reliable intrusion detection systems(IDSs).However,the advent of larger IDS datasets has negatively impacted the performance and computational complexity of AI-based IDSs.Many researchers used data preprocessing techniques such as feature selection and normalization to overcome such issues.While most of these researchers reported the success of these preprocessing techniques on a shallow level,very few studies have been performed on their effects on a wider scale.Furthermore,the performance of an IDS model is subject to not only the utilized preprocessing techniques but also the dataset and the ML/DL algorithm used,which most of the existing studies give little emphasis on.Thus,this study provides an in-depth analysis of feature selection and normalization effects on IDS models built using three IDS datasets:NSL-KDD,UNSW-NB15,and CSE–CIC–IDS2018,and various AI algorithms.A wrapper-based approach,which tends to give superior performance,and min-max normalization methods were used for feature selection and normalization,respectively.Numerous IDS models were implemented using the full and feature-selected copies of the datasets with and without normalization.The models were evaluated using popular evaluation metrics in IDS modeling,intra-and inter-model comparisons were performed between models and with state-of-the-art works.Random forest(RF)models performed better on NSL-KDD and UNSW-NB15 datasets with accuracies of 99.86%and 96.01%,respectively,whereas artificial neural network(ANN)achieved the best accuracy of 95.43%on the CSE–CIC–IDS2018 dataset.The RF models also achieved an excellent performance compared to recent works.The results show that normalization and feature selection positively affect IDS modeling.Furthermore,while feature selection benefits simpler algorithms(such as RF),normalization is more useful for complex algorithms like ANNs and deep neural networks(DNNs),and algorithms such as Naive Bayes are unsuitable for IDS modeling.The study also found that the UNSW-NB15 and CSE–CIC–IDS2018 datasets are more complex and more suitable for building and evaluating modern-day IDS than the NSL-KDD dataset.Our findings suggest that prioritizing robust algorithms like RF,alongside complex models such as ANN and DNN,can significantly enhance IDS performance.These insights provide valuable guidance for managers to develop more effective security measures by focusing on high detection rates and low false alert rates. 展开更多
关键词 CYBERSECURITY Intrusion detection system Machine learning Deep learning Feature selection normalIZATION
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Fluid therapy in acute pancreatitis comparing balanced solutions and normal saline:A systematic review,meta-analysis and trial sequential analysis 被引量:1
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作者 Lin Gao Hsiang-Wei Wang +4 位作者 Zi-Rui Liu Yi-Zhen Xu Lu Ke Wei-Qin Li John A Windsor 《Hepatobiliary & Pancreatic Diseases International》 2025年第4期371-380,共10页
Background:Isotonic crystalloids are recommended as the first choice for fluid therapy in acute pan-creatitis(AP),with normal saline(NS)and lactate Ringer’s(LR)used most often.Evidence based recom-mendations on the t... Background:Isotonic crystalloids are recommended as the first choice for fluid therapy in acute pan-creatitis(AP),with normal saline(NS)and lactate Ringer’s(LR)used most often.Evidence based recom-mendations on the type of fluid are conflicting and generally come from small single-center randomized controlled trials(RCTs).We therefore conducted a systematic review and meta-analysis to compare the effect of balanced solutions(BS)versus NS on patient-centered clinical outcomes in AP.Methods:From four databases searched up to October 2024,we included only RCTs of adult patients with AP that compared the use of BS(including LR,acetate Ringer’s,etc.)with NS.The primary out-come was the disease advances from AP to moderately severe and severe AP(MSAP/SAP).Trial sequential analyses(TSA)were conducted to control for type-I and type-II errors and Grading of Recommendations Assessment,Development,and Evaluation(GRADE)was used to assess the quality of evidence.Results:Six RCTs were identified and included,involving 260 patients treated with BS and 298 patients with NS.Patients who received the BS had less MSAP/SAP[odds ratio(OR)=0.50,95%confidence in-terval(CI):0.29 to 0.85,P=0.01,I^(2)=0%;5 studies,299 patients],reduced the need of ICU admission(OR=0.60,95%CI:0.39 to 0.93,P=0.02,I^(2)=0%;5 studies,507 patients)and shorter length of hospital stay[mean difference(MD)=-0.88,95%CI:-1.48 to-0.28,P=0.004,I^(2)=0%;6 studies,558 patients;confirmed by TSA with high certainty]compared with those who received NS.The evidence for most of the clinical outcomes was rated as moderate to low due to the risk of bias,imprecision and inconsistency.Conclusions:BS,compared with NS,was associated with improved clinical outcomes in patients with AP.However,given the moderate to low quality of evidence for most of the outcomes assessed,further trials are warranted. 展开更多
关键词 Acute pancreatitis Fluid therapy normal saline Balanced solution Systematic review
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Shear behaviors of intermittent joints subjected to shearing cycles under constant normal stiffness conditions:Effects of loading parameters 被引量:1
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作者 Bin Wang Yujing Jiang +1 位作者 Qiangyong Zhang Hongbin Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第5期2695-2712,共18页
A conceptual model of intermittent joints is introduced to the cyclic shear test in the laboratory to explore the effects of loading parameters on its shear behavior under cyclic shear loading.The results show that th... A conceptual model of intermittent joints is introduced to the cyclic shear test in the laboratory to explore the effects of loading parameters on its shear behavior under cyclic shear loading.The results show that the loading parameters(initial normal stress,normal stiffness,and shear velocity)determine propagation paths of the wing and secondary cracks in rock bridges during the initial shear cycle,creating different morphologies of macroscopic step-path rupture surfaces and asperities on them.The differences in stress state and rupture surface induce different cyclic shear responses.It shows that high initial normal stress accelerates asperity degradation,raises shear resistance,and promotes compression of intermittent joints.In addition,high normal stiffness provides higher normal stress and shear resistance during the initial cycles and inhibits the dilation and compression of intermittent joints.High shear velocity results in a higher shear resistance,greater dilation,and greater compression.Finally,shear strength is most sensitive to initial normal stress,followed by shear velocity and normal stiffness.Moreover,average dilation angle is most sensitive to initial normal stress,followed by normal stiffness and shear velocity.During the shear cycles,frictional coefficient is affected by asperity degradation,backfilling of rock debris,and frictional area,exhibiting a non-monotonic behavior. 展开更多
关键词 Intermittent joint Cyclic shear Loading parameter Constant normal stiffness(CNS)
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Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
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作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation Potential function Variational method normalized solution
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Normalized Positive Ground State Solutions for Nonhomogeneous Kirchhoff Equations
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作者 ZHANG Xiaocang XU Liping 《应用数学》 北大核心 2025年第3期711-720,共10页
This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of norm... This article studies a class of nonlinear Kirchhoff equations with exponential critical growth,trapping potential,and perturbation.Under appropriate assumptions about f and h,the article obtained the existence of normalized positive solutions for this equation via the Trudinger-Moser inequality and variational methods.Moreover,these solutions are also ground state solutions.Additionally,the article also characterized the asymptotic behavior of solutions.The results of this article expand the research of relevant literature. 展开更多
关键词 normalized positive ground state solution Nonhomogeneous Kirchhoff equation Variational method Exponential critical growth Trapping potential
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Supercavitating Projectile Tail-Slaps Based on a Normal Distribution
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作者 Kangjian Wang Youran Xia +1 位作者 Qizhuang Kang Youli Wu 《哈尔滨工程大学学报(英文版)》 2025年第2期398-414,共17页
The present study focuses on simulating supercavitating projectile tail-slaps with an analytical method.A model of 3σ-normal distribution tail-slaps for a supercavitating projectile is established.Meanwhile,theσ-κe... The present study focuses on simulating supercavitating projectile tail-slaps with an analytical method.A model of 3σ-normal distribution tail-slaps for a supercavitating projectile is established.Meanwhile,theσ-κequation is derived,which is included in this model.Next,the supercavitating projectile tail-slaps are simulated by combining the proposed model and the Logvinovich supercavity section expansion equation.The results show that the number of tail-slaps depends on where the initial several tail-slaps are under the same initial condition.If the distances between the initial several tail-slap positions are large,the number of tail-slaps will considerably decrease,and vice versa.Furthermore,a series of simulations is employed to analyze the influence of the initial angular velocity and the centroid.Analysis of variance is used to evaluate simulation results.The evaluation results suggest that the projectile’s initial angular velocity and centroid have a major impact on the tail-slap number.The larger the value of initial angular velocity,the higher the probability of an increase in tail-slap number.Additionally,the closer the centroid is to the projectile head,the less likely a tail-slap number increase.This study offers important insights into supercavitating projectile tail-slap research. 展开更多
关键词 Tail-slaps normal distribution Supercavity STABILITY Supercavitating projectile
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Relating normal stiffness to permeability of a deformed self-affine rough fracture using its geometric properties
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作者 Qinglin Deng Jianming Shangguan +3 位作者 Yinlin Ji Mauro Cacace Guido Blöcher Jean Schmittbuhl 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第5期2829-2842,共14页
In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability o... In subsurface projects where the host rock is of low permeability,fractures play an important role in fluid circulation.Both the geometrical and mechanical properties of the fracture are relevant to the permeability of the fracture.To evaluate this relationship,we numerically generated self-affine fractures reproducing the scaling relationship of the power spectral density(PSD)of the measured fracture surfaces.The fractures were then subjected to a uniform and stepwise increase in normal stress.A fast Fourier transform(FFT)-based elastic contact model was used to simulate the fracture closure.The evolution of fracture contact area,fracture closure,and fracture normal stiffness were determined throughout the whole process.In addition,the fracture permeability at each step was calculated by the local cubic law(LCL).The influences of roughness exponent and correlation length on the fracture hydraulic and mechanical behaviors were investigated.Based on the power law of normal stiffness versus normal stress,the corrected cubic law and the linear relationship between fracture closure and mechanical aperture were obtained from numerical modeling of a set of fractures.Then,we derived a fracture normal stiffness-permeability equation which incorporates fracture geometric parameters such as the root-mean-square(RMS),roughness exponent,and correlation length,which can describe the fracture flow under an effective medium regime and a percolation regime.Finally,we interpreted the flow transition behavior from the effective medium regime to the percolation regime during fracture closure with the established stiffness-permeability function. 展开更多
关键词 Fracture closure Elastic deformation Fluid flow PERMEABILITY normal stiffness Scaling relationship
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Analysis of Teaching Reform in Zoology Experiment Courses at Normal Universities Using Micro-video Instructional Models
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作者 Meiying FENG Yinghua WANG +5 位作者 Yu MEN Linqi HUANG Yanfeng LIANG Liangjing PENG Huimin ZHU Shuying FU 《Agricultural Biotechnology》 2025年第5期42-46,共5页
With the deep advancement of modern educational informatization,the micro-video teaching model has gradually become an effective approach for promoting the innovation and reform of experimental teaching,owing to its a... With the deep advancement of modern educational informatization,the micro-video teaching model has gradually become an effective approach for promoting the innovation and reform of experimental teaching,owing to its advantages such as intuitive visualization,repeatability,and flexible learning.This paper addressed the limitations of the traditional zoology experiment teaching model,which include insufficiently clear teacher demonstrations,limited class time,and the difficulty of accommodating individual student differences.Accordingly,we systematically analyzed the main characteristics,implementation models,and effectiveness of the micro-video teaching model in the Zoology Experiment course.We also discussed the primary challenges encountered during its teaching practice and proposed corresponding recommendations for improvement.This analysis aimed to provide a theoretical reference for the teaching reform of Zoology Experiment in normal universities. 展开更多
关键词 Micro-video teaching Zoology Experiment normal education Teaching reform
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Offshore Wind Turbines Anomalies Detection Based on a New Normalized Power Index
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作者 Bassel Weiss Segundo Esteban Matilde Santos 《Computer Modeling in Engineering & Sciences》 2025年第9期3387-3418,共32页
Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particular... Anomaly detection in wind turbines involves emphasizing its ability to improve operational efficiency,reduce maintenance costs,extend their lifespan,and enhance reliability in the wind energy sector.This is particularly necessary in offshore wind,currently one of the most critical assets for achieving sustainable energy generation goals,due to the harsh marine environment and the difficulty of maintenance tasks.To address this problem,this work proposes a data-driven methodology for detecting power generation anomalies in offshore wind turbines,using normalized and linearized operational data.The proposed framework transforms heterogeneous wind speed and power measurements into a unified scale,enabling the development of a new wind power index(WPi)that quantifies deviations from expected performance.Additionally,spatial and temporal coherence analyses of turbines within a wind farm ensure the validity of these normalized measurements across different wind turbine models and operating conditions.Furthermore,a Support Vector Machine(SVM)refines the classification process,effectively distinguishing measurement errors from actual power generation failures.Validation of this strategy using real-world data from the Alpha Ventus wind farm demonstrates that the proposed approach not only improves predictive maintenance but also optimizes energy production,highlighting its potential for broad application in offshore wind installations. 展开更多
关键词 Fault identification anomaly detection normalIZATION offshore wind turbines wind energy
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Effect of high-magnetic-field normalizing on microstructure and texture of grain-oriented silicon steel
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作者 Si-zhou Liu Zhao-yang Cheng +3 位作者 Yun-xiang Chen Juan Jia Shi-qi Zhang Jing Liu 《Journal of Iron and Steel Research International》 2025年第8期2525-2538,共14页
A grain-oriented silicon steel was normalized with a novel high magnetic field using one-stage cooling process.The effect of high-magnetic-field normalizing on the microstructures and textures was studied with a hot-r... A grain-oriented silicon steel was normalized with a novel high magnetic field using one-stage cooling process.The effect of high-magnetic-field normalizing on the microstructures and textures was studied with a hot-rolled sheet as initial material.It was found that recrystallization and the grain growth were enhanced owing to the external magnetic field driving force.The angle between Goss orientation and magnetic field direction was small,resulting in a high nucleation rate of Goss grains,and hence,the intensity of Goss texture was increased and the deviation angle of Goss grains was reduced after high-magnetic-field normalizing.Furthermore,the migration of dislocation was promoted with an external magnetic field driving force and the density of dislocation decreased,reducing the proportion of low-angle grain boundaries around the Goss grains.The enhancement of recrystallization process and grain growth increased the proportion of high-energy grain boundaries and high-angle grain boundaries,providing a favorable condition for the growth of Goss grains. 展开更多
关键词 High magnetic field Grain-oriented silicon steel normalIZING RECRYSTALLIZATION Goss texture
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Effect of adjacent excavation on the mechanical response of proximal soil and tunnels in normally consolidated clay:centrifuge model testing and numerical simulation
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作者 Ren-Peng CHEN Yong XU +1 位作者 Han-Lin WANG Fan-Yan MENG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 2025年第10期931-949,共19页
Urban spaces are becoming increasingly congested,and excavations are frequently performed close to existing underground structures such as tunnels.Understanding the mechanical response of proximal soil and tunnels to ... Urban spaces are becoming increasingly congested,and excavations are frequently performed close to existing underground structures such as tunnels.Understanding the mechanical response of proximal soil and tunnels to these excavations is important for efficient and safe underground construction.However,previous investigations of this issue have predominantly made assumptions of plane-strain conditions and normal gravity states,and focused on the performance of tunnels affected by excavation and unloading in sandy strata.In this study,a 3D centrifuge model test is conducted to investigate the influence of excavation on an adjacent existing tunnel in normally consolidated clay.The testing results indicate that the excavation has a significant impact on the horizontal deformation of the retaining wall and tunnel.Moreover,the settlements of the ground surface and the tunnel are mainly affected by the long-term period after excavation.The excavation is found to induce ground movement towards the pit,resulting in prolonged fluctuations in pore water pressure and lateral earth pressure.The testing results are compared with numerical simulations,achieving consistency.A numerical parametric study on the tunnel location shows that when the tunnel is closer to the retaining wall,the decreases in lateral earth pressure and pore water pressure during excavation are more pronounced. 展开更多
关键词 Centrifuge model Adjacent excavation TUNNEL Retaining wall normally consolidated clay
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Cultivation of the Educator Spirit among Mathematics Normal Students:Value,Dilemma,and Path
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作者 Jin Liu Meng Yan Yufan Niu 《Journal of Contemporary Educational Research》 2025年第3期187-197,共11页
The cultivation of the educator spirit among normal university students provides dual guidance in theory and practice for higher education institutions to train future teachers with noble educational sentiments and pr... The cultivation of the educator spirit among normal university students provides dual guidance in theory and practice for higher education institutions to train future teachers with noble educational sentiments and professional qualities.This study elaborates on the essential connotation of the educator spirit from six perspectives:guiding philosophy,spiritual cultivation,internal requirements,essential requirements,the soul of teacher ethics,and sources of motivation.On this basis,it explains the three major dilemmas in cultivating the educator spirit among normal university students:the cognitive dilemma regarding the understanding of the value of the educator spirit and educational identity,the integration dilemma caused by the disconnection between educational curriculum design and the penetration of the educator spirit,and the alienation dilemma arising from improper connection between educational practice and the educator spirit.Therefore,it is proposed to incorporate the educator spirit into the evaluation system for normal university students,by deepening the understanding of values,optimizing curriculum design,strengthening practice orientation,and comprehensively motivating and evaluating normal university students’recognition and practice of the educator spirit,in order to promote the inheritance and innovation of the educator spirit. 展开更多
关键词 Educator spirit Training of normal students Value connotation DILEMMAS Pathways
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Research on the Construction of an Evaluation System for Innovation and Entrepreneurship Capabilities of Normal University Students Based on Factor Analysis Method
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作者 Fang Liu Chi Li Lihua Jia 《Journal of Contemporary Educational Research》 2025年第8期320-327,共8页
Under the National Innovation-Driven Development Strategy,establishing a scientifically sound evaluation system for normal university students’innovation and entrepreneurship capabilities serves as a crucial foundati... Under the National Innovation-Driven Development Strategy,establishing a scientifically sound evaluation system for normal university students’innovation and entrepreneurship capabilities serves as a crucial foundation for optimizing innovation education models and enhancing teacher candidates’comprehensive competencies.Based on existing indicator frameworks,we designed a questionnaire and applied exploratory factor analysis(EFA)to screen indicators,reduce dimensionality,and analyze weighting.This process identified key metrics for evaluating pedagogical students’innovation capacities,ultimately constructing a targeted assessment system for normal university students.The study provides theoretical support for cultivating teacher trainees’innovative capabilities while contributing to the national innovation strategy implementation. 展开更多
关键词 Factor analysis Innovation and entrepreneurship capability Indicator system Evaluation system UNIVERSITIES normal university students
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Rate-frequency dependent shear behavior of rough rock joint experiencing normal load oscillations
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作者 DANG Wen-gang LI Xing-ling +1 位作者 TAO Kang FU Jin-yang 《Journal of Central South University》 2025年第5期1873-1886,共14页
Dynamic disturbances certainly reduce shear strength of rock joints,yet the mechanism needs deeper explanation.We investigate the shear behavior of a rough basalt joint by conducting laboratory shear experiments.Const... Dynamic disturbances certainly reduce shear strength of rock joints,yet the mechanism needs deeper explanation.We investigate the shear behavior of a rough basalt joint by conducting laboratory shear experiments.Constant and superimposed oscillating normal loads are applied at the upper block.Meanwhile,the bottom block moves at a constant shear rate.We investigate the shear behavior by:1)altering the normal load oscillation frequency with a same shear rate,2)altering the shear rate with a same normal load oscillation frequency,and 3)altering the normal load oscillation frequency and shear rate simultaneously with a constant ratio.The results show that the oscillating normal load reduces the coefficient of friction(COF).The reduce degree of COF increases with higher shear rate,decreases when increasing normal load oscillation frequency,and keeps constant if the special ratio,v/f(shear rate divided by normal oscillation frequency),is constant.Moreover,we identify a time lag between peak normal load and peak shear load.And the lagging proportion increases with higher shear rate,and decreases with larger static COF.Our results imply that a lower creep rate with a higher normal load oscillation frequency easily destabilizes the creeping fault zones. 展开更多
关键词 normal load oscillation shear rate oscillation frequency friction reduction time lag
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Revisiting the normal stiffness–permeability relations for shale fractures under true triaxial stress
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作者 Fudong Li Derek Elsworth +6 位作者 Xia-Ting Feng Tianyu Chen Jun Zhao Yingchun Li Jianyu Zhang Qiong Wu Guanglei Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期5001-5017,共17页
Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crus... Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crust.Previous data on stiffness–permeability relations are measured under uniaxial stress states as well as under normal stress.However,many projects involve faulted formations with complex three-dimensional(3D)stress states or significant changes to the original stress state.We rectified this by following the permeability evolution using a true-triaxial stress-permeability apparatus as well as independently applying a spectrum of triaxial stresses from low to high.The relationship between permeability and fracture normal stiffness was quantified using constraints based on the principle of virtual work.The impacts of fracture-lateral and fracture-normal stresses on permeability and normal stiffness evolution were measured.It was found that permeability decreases with increasing fracture-lateral and fracture-normal stresses as a result of Poisson confinement,independent of the orientation of the fracture relative to the stresses.The lateral stresses dominated the evolution of normal stiffness at lower normal stresses(σ_(3)=10 MPa)and played a supplementary role at higher normal stresses(σ_(3)>10 MPa).Moreover,correlations between the evolution of permeability and normal stiffness were extended beyond the low-stiffness,high-permeability region to the high-stiffness,low-permeability region under high fracture-lateral stresses(10–80 MPa)with fracture-normal stress(10–50 MPa)conditions.Again,high lateral stresses further confined the fracture and therefore reduced permeability and increased normal stiffness,which exceeded the previous reported stiffness under no lateral stress conditions.This process enabled us to identify a fundamental change in the flow regime from multi-channel to isolated channelized flow.These results provide important characterizations of fracture permeability in the deep crust,including recovery from deep shale-gas reservoirs. 展开更多
关键词 Fracture permeability Deformation Fracture normal stiffness True-triaxial stress Principle of virtual work
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Switchable Normalization Based Faster RCNN for MRI Brain Tumor Segmentation
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作者 Rachana Poongodan Dayanand Lal Narayan +2 位作者 Deepika Gadakatte Lokeshwarappa Hirald Dwaraka Praveena Dae-Ki Kang 《Computers, Materials & Continua》 2025年第9期5751-5772,共22页
In recent decades,brain tumors have emerged as a serious neurological disorder that often leads to death.Hence,Brain Tumor Segmentation(BTS)is significant to enable the visualization,classification,and delineation of ... In recent decades,brain tumors have emerged as a serious neurological disorder that often leads to death.Hence,Brain Tumor Segmentation(BTS)is significant to enable the visualization,classification,and delineation of tumor regions in Magnetic Resonance Imaging(MRI).However,BTS remains a challenging task because of noise,non-uniform object texture,diverse image content and clustered objects.To address these challenges,a novel model is implemented in this research.The key objective of this research is to improve segmentation accuracy and generalization in BTS by incorporating Switchable Normalization into Faster R-CNN,which effectively captures the fine-grained tumor features to enhance segmentation precision.MRI images are initially acquired from three online datasets:Dataset 1—Brain Tumor Segmentation(BraTS)2018,Dataset 2—BraTS 2019,and Dataset 3—BraTS 2020.Subsequently,the Switchable Normalization-based Faster Regions with Convolutional Neural Networks(SNFRC)model is proposed for improved BTS in MRI images.In the proposed model,Switchable Normalization is integrated into the conventional architecture,enhancing generalization capability and reducing overfitting to unseen image data,which is essential due to the typically limited size of available datasets.The network depth is increased to obtain discriminative semantic features that improve segmentation performance.Specifically,Switchable Normalization captures the diverse feature representations from the brain images.The Faster R-CNN model develops end-to-end training and effective regional proposal generation,with an enhanced training stability using Switchable Normalization,to perform an effective segmentation in MRI images.From the experimental results,the proposed model attains segmentation accuracies of 99.41%,98.12%,and 96.71%on Datasets 1,2,and 3,respectively,outperforming conventional deep learning models used for BTS. 展开更多
关键词 Brain tumor segmentation computer-aided system deep learning models magnetic resonance imaging medical images switchable normalization
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Cyclic shear responses of rough-walled rock joints subjected to dynamic normal loads
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作者 Qiang Zhu Qian Yin +1 位作者 Zhigang Tao Manchao He 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第5期3289-3297,共9页
In rock engineering,the cyclic shear characteristics of rough joints under dynamic disturbances are still insufficiently studied.This study conducted cyclic shear experiments on rough joints under dynamic normal loads... In rock engineering,the cyclic shear characteristics of rough joints under dynamic disturbances are still insufficiently studied.This study conducted cyclic shear experiments on rough joints under dynamic normal loads to assess the impact of shear frequency(f_(h))and shear displacement amplitude(u_(d))on the frictional properties of the joint.The results reveal that within a single shearing cycle,the normal displacement negatively correlates with the dynamic normal force.As the shear cycle number increases,the joint surface undergoes progressive wear,resulting in an exponential decrease in the peak normal displacement.In the cyclic shearing procedure,the forward peak values of shear force and friction coefficient display larger fluctuations at either lower or higher shear frequencies.However,under moderate shear frequency conditions,the changes in the shear strength of the joint surface are smaller,and the degree of degradation post-shearing is relatively limited.As the shear displacement amplitude increases,the range of normal deformation within the joint widens.Furthermore,after shearing,the corresponding joint roughness coefficient trend shows a gradual decrease with an increasing shear displacement amplitude,while varying with the shearing frequency in a pattern that initially rises and then falls,with a turning point at 0.05 Hz.The findings of this research contribute to a profound comprehension of the cyclic frictional properties of rock joints under dynamic disturbances. 展开更多
关键词 Dynamic normal load Dynamic shear load Rough joints Friction mechanisms
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A Crossover Trial of Hospital-Wide Lactated Ringer's Solution versus Normal Saline
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作者 Lauralyn McIntyre 《四川生理科学杂志》 2025年第6期1276-1276,共1页
Background:Whether lactated Ringer's solution is clinically superior to normal saline for routine intravenous administration of fluids is uncertain.Methods:In an open-label,two-period,two-sequence,cross-sectional,... Background:Whether lactated Ringer's solution is clinically superior to normal saline for routine intravenous administration of fluids is uncertain.Methods:In an open-label,two-period,two-sequence,cross-sectional,cluster-randomized,crossover trial,we assigned hospitals in Ontario,Canada,to use either lactated Ringer's solution or normal saline hospital-wide for a period of 12 weeks. 展开更多
关键词 normal saline crossover trial clinical superiority lactated ringers solution hospital wide intravenous administration fluids intravenous administration
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