期刊文献+
共找到639篇文章
< 1 2 32 >
每页显示 20 50 100
DriftXMiner: A Resilient Process Intelligence Approach for Safe and Transparent Detection of Incremental Concept Drift in Process Mining
1
作者 Puneetha B.H Manoj Kumar M.V +1 位作者 Prashanth B.S. Piyush Kumar Pareek 《Computers, Materials & Continua》 2026年第1期1086-1118,共33页
Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental con... Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental concept drift,gradually alter the behavior or structure of processes,making their detection and localization a challenging task.Traditional process mining techniques frequently assume process stationarity and are limited in their ability to detect such drift,particularly from a control-flow perspective.The objective of this research is to develop an interpretable and robust framework capable of detecting and localizing incremental concept drift in event logs,with a specific emphasis on the structural evolution of control-flow semantics in processes.We propose DriftXMiner,a control-flow-aware hybrid framework that combines statistical,machine learning,and process model analysis techniques.The approach comprises three key components:(1)Cumulative Drift Scanner that tracks directional statistical deviations to detect early drift signals;(2)a Temporal Clustering and Drift-Aware Forest Ensemble(DAFE)to capture distributional and classification-level changes in process behavior;and(3)Petri net-based process model reconstruction,which enables the precise localization of structural drift using transition deviation metrics and replay fitness scores.Experimental validation on the BPI Challenge 2017 event log demonstrates that DriftXMiner effectively identifies and localizes gradual and incremental process drift over time.The framework achieves a detection accuracy of 92.5%,a localization precision of 90.3%,and an F1-score of 0.91,outperforming competitive baselines such as CUSUM+Histograms and ADWIN+Alpha Miner.Visual analyses further confirm that identified drift points align with transitions in control-flow models and behavioral cluster structures.DriftXMiner offers a novel and interpretable solution for incremental concept drift detection and localization in dynamic,process-aware systems.By integrating statistical signal accumulation,temporal behavior profiling,and structural process mining,the framework enables finegrained drift explanation and supports adaptive process intelligence in evolving environments.Its modular architecture supports extension to streaming data and real-time monitoring contexts. 展开更多
关键词 Process mining concept drift gradual drift incremental drift clustering ensemble techniques process model event log
在线阅读 下载PDF
Local Rate of Convergence in the Functional Limit Theorem for Increments of a Fractional Brownian Motion 被引量:1
2
作者 LIU Yonghong DING Ding ZHOU Xia 《数学进展》 北大核心 2025年第1期197-211,共15页
In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):104... In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):1045-1049]and Monrad and Rootzén[Probab.Theory Related Fields,1995,101(2):173-192]. 展开更多
关键词 fractional Brownian motion INCREMENT local functional law of the iterated logarithm large deviation small deviation
原文传递
An asymmetrically variable wingtip anhedral angles morphing aircraft based on incremental sliding mode control:Improving lateral maneuver capability 被引量:2
3
作者 Xiaodong LIU Yong XU Jianqiao LUO 《Chinese Journal of Aeronautics》 2025年第1期455-470,共16页
This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic mo... This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver capability.Firstly,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual inputs.Secondly,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown disturbances.The whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function method.Furthermore,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and rudder.Actuator dynamic models are incorporated to ensure physical realizability of designed allocation law.Finally,comparative experimental results validate the effectiveness of the designed control system and control allocation law.The NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),respectively.The design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering. 展开更多
关键词 Morphing aircraft Lateral maneuver capability Incremental sliding mode control Multi-Lyapunov function method Control theory Control allocation law
原文传递
Geometric size and forming force prediction in incremental flanging:A new analytical model 被引量:1
4
作者 Chong TIAN Dawei ZHANG +1 位作者 Guangcan YANG Shengdun ZHAO 《Chinese Journal of Aeronautics》 2025年第2期519-540,共22页
A new analytical model for geometric size and forming force prediction in incremental flanging(IF)is presented in this work.The complex deformation characteristics of IF are considered in the modeling process,which ca... A new analytical model for geometric size and forming force prediction in incremental flanging(IF)is presented in this work.The complex deformation characteristics of IF are considered in the modeling process,which can accurately describe the strain and stress states in IF.Based on strain analysis,the model can predict the material thickness distribution and neck height after IF.By considering contact area,strain characteristics,material thickness changes,and friction,the model can predict specific moments and corresponding values of maximum axial forming force and maximum horizontal forming force during IF.In addition,an IF experiment involving different tool diameters,flanging diameters,and opening hole diameters is conducted.On the basis of the experimental strain paths,the strain characteristics of different deformation zones are studied,and the stable strain ratio is quantitatively described through two dimensionless parameters:relative tool diameter and relative hole diameter.Then,the changing of material thickness and forming force in IF,and the variation of minimum material thickness,neck height,maximum axial forming force,and maximum horizontal forming force with flanging parameters are studied,and the reliability of the analytical model is verified in this process.Finally,the influence of the horizontal forming force on the tool design and the fluctuation of the forming force are explained. 展开更多
关键词 Incremental flanging Analytical model Strain characteristic Geometric size Forming force
原文传递
Investigation of spatiotemporal distribution and formation mechanisms of ozone pollution in eastern Chinese cities applying convolutional neural network 被引量:1
5
作者 Qiaoli Wang Dongping Sheng +7 位作者 Chengzhi Wu Xiaojie Ou Shengdong Yao Jingkai Zhao Feili Li Wei Li Jianmeng Chen 《Journal of Environmental Sciences》 2025年第2期126-138,共13页
Severe ground-level ozone(O_(3))pollution over major Chinese cities has become one of the most challenging problems,which have deleterious effects on human health and the sustainability of society.This study explored ... Severe ground-level ozone(O_(3))pollution over major Chinese cities has become one of the most challenging problems,which have deleterious effects on human health and the sustainability of society.This study explored the spatiotemporal distribution characteristics of ground-level O_(3) and its precursors based on conventional pollutant and meteorological monitoring data in Zhejiang Province from 2016 to 2021.Then,a high-performance convolutional neural network(CNN)model was established by expanding the moment and the concentration variations to general factors.Finally,the response mechanism of O_(3) to the variation with crucial influencing factors is explored by controlling variables and interpolating target variables.The results indicated that the annual average MDA8-90th concentrations in Zhejiang Province are higher in the northern and lower in the southern.When the wind direction(WD)ranges from east to southwest and the wind speed(WS)ranges between 2 and 3 m/sec,higher O_(3) concentration prone to occur.At different temperatures(T),the O_(3) concentration showed a trend of first increasing and subsequently decreasing with increasing NO_(2) concentration,peaks at the NO_(2) concentration around 0.02mg/m^(3).The sensitivity of NO_(2) to O_(3) formation is not easily affected by temperature,barometric pressure and dew point temperature.Additionally,there is a minimum IRNO_(2) at each temperature when the NO_(2) concentration is 0.03 mg/m^(3),and this minimum IRNO_(2) decreases with increasing temperature.The study explores the response mechanism of O_(3) with the change of driving variables,which can provide a scientific foundation and methodological support for the targeted management of O_(3) pollution. 展开更多
关键词 OZONE Spatiotemporal distribution Convolutional neural network Ozone formation rules Incremental reactivity
原文传递
Influence of geometric configurations on friction characteristics during incremental forming process of AA5052 sheet metal 被引量:1
6
作者 Guang-can YANG Da-wei ZHANG +1 位作者 Chong TIAN Sheng-dun ZHAO 《Transactions of Nonferrous Metals Society of China》 2025年第3期715-733,共19页
The influence of geometric configuration on the friction characteristics during incremental sheet forming of AA5052 was analyzed by integrating surface morphology and its characteristic parameters,along with plastic s... The influence of geometric configuration on the friction characteristics during incremental sheet forming of AA5052 was analyzed by integrating surface morphology and its characteristic parameters,along with plastic strain,contact pressure,and area.The interface promotes lubrication and support when wall angles were≤40°,a 0.5 mm-thin sheet was used,and a 10 mm-large tool radius was employed.This mainly results in micro-plowing and plastic extrusion flow,leading to lower friction coefficient.However,when wall angles exceed 40°,significant plastic strain roughening occurs,leading to inadequate lubrication on the newly formed surface.Increased sheet thickness and decreased tool radius elevate contact pressure.These actions trigger micro-cutting and adhesion,potentially leading to localized scuffing and dimple tears,and higher friction coefficient.The friction mechanisms remain unaffected by the part’s plane curve features.As the forming process progresses,abrasive wear intensifies,and surface morphology evolves unfavorably for lubrication and friction reduction. 展开更多
关键词 AA5052 sheet metal incremental forming process geometric configurations surface morphology characteristics friction mechanism
在线阅读 下载PDF
Advancements in incremental nonlinear dynamic inversion and its components:A survey on INDI-PartⅡ 被引量:1
7
作者 Agnes STEINERT Stefan RAAB +2 位作者 Simon HAFNER Florian HOLZAPFEL Haichao HONG 《Chinese Journal of Aeronautics》 2025年第11期286-314,共29页
Incremental Nonlinear Dynamic Inversion(INDI)is a control approach that has gained popularity in flight control over the past decade.Besides the INDI law,several common additional components complement an INDI-based c... Incremental Nonlinear Dynamic Inversion(INDI)is a control approach that has gained popularity in flight control over the past decade.Besides the INDI law,several common additional components complement an INDI-based controller.This paper,the second part of a two-part series of surveys on INDI,aims to summarize the modern trends in INDI and its related components.Besides a comprehensive components specification,it addresses their most common challenges,compares different variants,and discusses proposed advances.Further important aspects of INDI are gain design,stability,and robustness.This paper also provides an overview of research conducted concerning these aspects.This paper is written in a tutorial style to familiarize researchers with the essential specifics and pitfalls of INDI and its components.At the same time,it can also serve as a reference for readers already familiar with INDI. 展开更多
关键词 Flight control Feedback linearization Dynamic inversion Incremental Nonlinear Dynamic Inversion(INDI) Reference model Control allocation Stability and robustness
原文传递
Effects of Forest Litter on Soil Carbon Dynamics in Funiu Mountain Region
8
作者 ZHANG Zizheng SU Yanan +1 位作者 WANG Zhiheng TIAN Yaowu 《Journal of Landscape Research》 2025年第2期7-10,16,共5页
Soil organic carbon(SOC)from different sources and with distinct chemical properties exhibit variations in their accumulation mechanisms.Exploring the effects of different litter treatments on SOC storage is of great ... Soil organic carbon(SOC)from different sources and with distinct chemical properties exhibit variations in their accumulation mechanisms.Exploring the effects of different litter treatments on SOC storage is of great significance for understanding the formation and accumulation mechanisms of the SOC pool.The feedback mechanisms of new and old SOC in response to tree species and litter treatments were quantitatively analyzed by the C3 plant/C4 soil replacement method.The litter treatments included no litter,aboveground litter,belowground forest litter,and aboveground+belowground litter,totaling four treatments.The results showed that in the first year,cork oak(Quercusvariabilis)exhibited the highest net SOC content increment and net new SOC increment,but the values declined rapidly from the second year onward.The net increment in SOC content was positive at all sample sites,while the priming effect was not significant at any site.Litter treatments had a significant impact on both SOC content and net SOC increment.Compared with aboveground litter,belowground litter was more effective in increasing SOC Content and net SOC increment. 展开更多
关键词 LITTER SOC INCREMENT Funiu Mountain Quercusvariabilis
在线阅读 下载PDF
A Study of the Association Between Structural Trends Stocks Influenced by Investor Preferences and Broad Market Index Movements
9
作者 Hao Fu 《Proceedings of Business and Economic Studies》 2025年第3期136-143,共8页
By using the Chinese stock market data from 2018 to 2024,the weak association between structural trends stocks and market index under investors’preference effect in trading cause the market is lack of liquidity and m... By using the Chinese stock market data from 2018 to 2024,the weak association between structural trends stocks and market index under investors’preference effect in trading cause the market is lack of liquidity and more likely to be dominated by structural trends,as in this market,the willingness to engage in passive trading exceeds that for active trading and investors’preference easy to reverse toward market volatility.The lack of incremental capital in the market often leads to sector-specific rallies rather than broad-based increases,which is one of the key reasons why the Chinese stock market has struggled to achieve overall growth over the long-term period. 展开更多
关键词 Preference Structural trends LIQUIDITY Passive trading Incremental capital
在线阅读 下载PDF
Acceleration of sheet metal spinning simulation by multi-mesh method
10
作者 Zhuolei ZHAI Mei ZHAN +2 位作者 Zhipeng SHI Yunda DONG Xiaoguang FAN 《Chinese Journal of Aeronautics》 2025年第7期651-668,共18页
Sheet metal spinning is an incremental forming process for producing axisymmetric thinwalled parts through continuous local deformation under the action of rollers.While studying the spinning process by finite element... Sheet metal spinning is an incremental forming process for producing axisymmetric thinwalled parts through continuous local deformation under the action of rollers.While studying the spinning process by finite element(FE)method,a critical bottleneck is the enormous simulation time.For beating off this challenge,a novel multi-mesh method is developed.The method can dynamically track the movement of rollers and adaptively refine the mesh.Thus,a locally refined quadrilateral computation mesh can be generated in the locally-deforming zone and reduce the unnecessary fine elements outside the locally-deforming zone.In the multi-mesh system,the fine elements and coarse elements are extracted from a storage mesh and a background mesh,respectively.Meanwhile,the hanging nodes in the locally refined mesh are removed by designing 4-refinement templates.Between computation mesh and storage mesh,a bi-cubic parametric surface fitting algorithm and accurate remapping methods are conducted to transmit geometric information and physical fields.The proposed method has been verified by two spinning processes.The results suggest that the method can save time by up to about 67%with satisfactory accuracy,especially for distributions of thickness and strain compared with the fully refined mesh. 展开更多
关键词 SPINNING Incremental forming Multi-mesh method Data remapping Adaptive remeshing ABAQUS
原文传递
Recruitment dynamics in conifer-dominated uneven-aged forests in the carpathians
11
作者 Jaroslav Vencurik Michal Bosela +7 位作者 Ladislav Sumichrast Anna Petrová Peter Jaloviar Denisa Sedmáková Zuzana Parobeková Ján Pittner Ivan Repác Stanislav Kucbel 《Forest Ecosystems》 2025年第5期963-973,共11页
In permanently uneven-aged forests, continuous ingrowth of recruitment into higher stand layers is a critical process for the formation and maintenance of differentiated stand structures. This study analyses the abund... In permanently uneven-aged forests, continuous ingrowth of recruitment into higher stand layers is a critical process for the formation and maintenance of differentiated stand structures. This study analyses the abundance and diversity of recruitment(diameter at breast high(DBH) 0.1–4 cm) across 241 research plots in 11 structurally differentiated Norway spruce(silver fir)-dominated forest stands distributed at altitudes between 500 and 1,440 m a.s.l. The influence of light conditions and lateral competition characteristics on the height increment and crown architecture of recruitment was investigated in detail for 352 Norway spruce and 361 silver fir trees. Light-related variables were confirmed to directly affect the recruitment distribution only to a limited extent. Under relatively low light conditions in montane stands, silver fir reached higher height increments than Norway spruce. The better adaptation of silver fir to shaded conditions was reflected also in its higher apical dominance ratio compared to Norway spruce. The height increment and apical dominance ratio of Norway spruce and silver fir recruitment were positively correlated with indirect radiation, DBH, and relative crown length(RCL), but not with lateral competition. These results confirm that the regulation of light conditions in permanently unevenaged stands is crucial for the growth dynamics of recruitment, as well as for the future proportions of Norway spruce and silver fir in mixed, structurally diverse stands. 展开更多
关键词 Norway spruce Silver fir Height increment Indirect light Crown architecture
在线阅读 下载PDF
Economic outcomes of AI-based diabetic retinopathy screening:a systematic review and meta-analysis
12
作者 Yue Wu Yueye Wang +5 位作者 Jian Zhang Yanxian Chen Keyao Zhou Chi Liu Xiaotong Han Mingguang He 《Eye Science》 2025年第2期121-135,共15页
Objective:Diabetic retinopathy(DR)is a top leading cause of blindness worldwide,requiring early detection for timely intervention.Artificial intelligence(AI)has emerged as a promising tool to improve DR screening effi... Objective:Diabetic retinopathy(DR)is a top leading cause of blindness worldwide,requiring early detection for timely intervention.Artificial intelligence(AI)has emerged as a promising tool to improve DR screening efficiency,accessibility,and cost-effectiveness.This study conducted a systematic review of literature and meta-analysis on the economic outcomes of AI-based DR screening.Methods:A systematic review of studies published before September 2024 was conducted throughout PubMed,Scopus,Embase,the Cochrane Library,the National Health Service Economic Evaluation Database,and the Cost-Effectiveness Analysis Registry.Eligible studies were included if they were(1)conducted among type 1 diabetes mellitus or type 2 diabetes mellitus adult diabetic population;(2)studies compared AI-based DR screening strategy to non-AI screening;and(3)performed a cost-effectiveness analysis.Meta-analysis was applied to pool incremental net benefit(INB)across studies stratified by country income and study perspective using a random-effects model.Statistical heterogeneity among studies was assessed using the I2 statistic,Cochrane Q statistics,and meta regression.Results:Nine studies were included in the analysis.From a healthcare system/payer perspective,AI-based DR screening was significantly cost-effective compared to non-AI-based screening,with a pooled INB of 615.77(95%confidence interval[CI]:558.27-673.27).Subgroup analysis showed robust cost-effectiveness of AI-based DR screening in high-income countries(INB=613.62,95%CI:556.06-671.18)and upper-/lower-middle income countries(INB=1,739.97,95%CI:423.13-3,056.82)with low heterogeneity.From a societal perspective,AI-based DR screening was generally cost-effective(INB=5,102.33,95%CI:-815.47-11,020.13),though the result lacked statistical significance and showed high heterogeneity.Conclusions:AI-based DR screening is generally cost-effective from a healthcare system perspective,particularly in high-income countries.Heterogeneity in cost-effectiveness across different perspectives highlights the importance of context-specific evaluations,to accurately evaluate the potential of AI-based DR screening in reducing global healthcare disparities. 展开更多
关键词 economic evaluation incremental net benefit META-ANALYSIS artificial intelligence diabetic retinopathy
暂未订购
Application of Dual-Polarization Radar Data Assimilation Via a Deep UNet Network Model
13
作者 XIA Xin YIN Peng-shuai +8 位作者 WAN Qi-lin GAO Yan WANG Hong FENG Jia-li MA Yu-long JIN Yu-chao SUN Jian SUN Shu-yue ZENG Qing-feng 《Journal of Tropical Meteorology》 2025年第6期591-602,共12页
The assimilation of dual-polarization(dual-pol)radar data plays a crucial role in enhancing the simulation of hydrometeors and improving the short-term precipitation forecasts of numerical weather prediction(NWP)model... The assimilation of dual-polarization(dual-pol)radar data plays a crucial role in enhancing the simulation of hydrometeors and improving the short-term precipitation forecasts of numerical weather prediction(NWP)models.However,existing dual-pol radar data assimilation(DA)methods exhibit limitations in terms of computational efficiency and data utilization.In this study,a new dual-pol radar DA approach is developed that utilizes a UNet-based model to retrieve mixing ratio information for four hydrometeor species from dual-pol radar data.The validation results for the UNet-based model indicate that the distributions of the retrieved hydrometeor mixing ratios provided by the model align well with the labeled data,yielding a reasonable range of root mean square errors(RMSEs).On this basis,the hydrometeor analysis increments retrieved by the UNet-based model are incorporated into the model integration process through the incremental analysis update(IAU)scheme,establishing a complete dual-pol radar DA framework for the CMA-MESO model.To evaluate the efficacy of this DA scheme,comparative simulation experiments were conducted for Typhoon Lekima(2019).Verification results indicate that using the hydrometeor DA scheme generally improves the threat scores(TSs)for 3-hour accumulated precipitation during medium-and heavy-rainfall events.Additionally,the 24-hour accumulated rainfall TSs for the medium-,heavy-,and extreme-precipitation categories in the DA experiment are all superior to those in the control experiment.The DA method also yields superior predictions of the spatial distribution of extremerainfall events.These results demonstrate that the proposed dual-pol radar DA approach effectively enhances the precipitation forecasting capabilities of numerical weather models. 展开更多
关键词 dual-polarization radar data assimilation UNet network incremental analysis update tropical cyclone
在线阅读 下载PDF
Seasonal Prediction of Pre-Summer Clustered Heavy Precipitation Days in South China
14
作者 ZHI Yao HAN Ting-ting +3 位作者 JIANG Shun-li WANG Hui-jun HAO Xin LI Shang-feng 《Journal of Tropical Meteorology》 2025年第1期107-119,共13页
Clustered heavy precipitation(CHP)events can severely impact human society,infrastructure,and natural ecosystems.Consequently,short-term climate prediction of CHP events is vital for the prevention and mitigation of a... Clustered heavy precipitation(CHP)events can severely impact human society,infrastructure,and natural ecosystems.Consequently,short-term climate prediction of CHP events is vital for the prevention and mitigation of associated hazards.Employing year-to-year increment(DY)and multiple linear regression approaches,this study developed a seasonal prediction model for pre-summer(i.e.,May and June)CHP frequency in South China(SC)during 1981–2022.Three robust predictor factors were identified:March sea surface temperature in Southwestern Atlantic,early-winter snow depth in East Europe,and winter soil moisture in Central Asia.Three predictors exert substantial impacts on presummer precipitation in SC via modulation of an anomalous anticyclone(cyclone)over the(subtropical)western North Pacific.In leave-one-out cross-validation test during 1981–2022,the prediction model exhibited reasonable performance in predicting the interannual and interdecadal variations and trends of CHP days.The temporal correlation coefficient(TCC)was 0.66 between the observations and predictions.In the independent hindcast for 2013–2022,the TCC was as high as 0.85.Moreover,coherent covariations were observed between the frequency and the amounts of CHP,with a TCC of 0.99 for 1981–2022.Those three predictors show good performance in forecasting CHP amounts over SC,with a TCC of 0.68 between the predictions and observations in the cross-validation test during 1981–2022 and of 0.86 in the independent hindcasts during 2013–2022.Notably,the predictors also showed good predictive skill for years with high CHP occurrence(e.g.,1998 and 2019).The predicted high-incidence areas of heavy precipitation days were highly consistent with observations,with a pattern correlation coefficient of 0.44(0.55)for 1998(2019).This study provides valuable insights to improve seasonal prediction of pre-summer CHP frequency in SC. 展开更多
关键词 seasonal prediction clustered heavy precipitation South China interannual increment
在线阅读 下载PDF
New insights into combined thermal and vibration softening of magnesium alloy in rotational vibration assisted incremental sheet forming
15
作者 Hui Zhu Xiaohan Zeng +1 位作者 Hui Long João Quinta da Fonseca 《Journal of Magnesium and Alloys》 2025年第12期6021-6046,共26页
With the generation of both localised thermal and vibration in incremental sheet forming(ISF)by novel tool designs,rotational vibration assisted ISF(RV-ISF)can achieve significant force reduction and material softenin... With the generation of both localised thermal and vibration in incremental sheet forming(ISF)by novel tool designs,rotational vibration assisted ISF(RV-ISF)can achieve significant force reduction and material softening.However,the combined thermal and vibration softening in RV-ISF is unclear.By evaluating the similarities and differences of friction stir ISF(FS-ISF)and RV-ISF,this study develops a novel approach to decouple and quantify the thermal and vibration softening effects in RV-ISF of AZ31B-H24,providing new insights into underlying thermal and vibration softening mechanism.Experimental results reveal that in RV-ISF of AZ31B-H24 the thermal softening due to frictional heating dominates with 45∼65%of softening,while the vibration effect only contributes up to 15%of softening,from the conventional ISF,depending on the tool designs and tool rotational speed.The double-offset tool(T2)produces greater vibration softening than the three-groove tool(T3)owing to the higher vibration amplitude of the T2 tool.An increase in tool rotational speed primarily enhances thermal softening with only marginal changes to the vibration effect.Microstructural analysis suggests that with average grain size of 0.94μm at the top layer,RV-ISF with T3 and 3000 rpm is more effective for microstructure refinement than that by FS-ISF,especially on the tool-sheet contact surface,which confirms the occurrence of surface shearing.This refinement is a result of the reduced recrystallisation degree,71.8%at the top bottom layer.Compared with FS-ISF,RV-ISF can lead to not only higher geometrically necessary dislocation density,but also higher fraction of low-angle grain boundaries,indicating that softening mechanism due to localised vibration effect is resulted from the enhanced rearrangement and annihilation of dislocations.These findings contribute to new understanding of the thermal and vibration softening effects in RV-ISF of AZ31B-H24 and offer a theoretical foundation for the tool design and process optimisation. 展开更多
关键词 Incremental sheet forming Magnesium alloy Vibration softening Thermal softening Microstructure evolution
在线阅读 下载PDF
A Novel Approach to Enhanced Cancelable Multi-Biometrics Personal Identification Based on Incremental Deep Learning
16
作者 Ali Batouche Souham Meshoul +1 位作者 Hadil Shaiba Mohamed Batouche 《Computers, Materials & Continua》 2025年第5期1727-1752,共26页
The field of biometric identification has seen significant advancements over the years,with research focusing on enhancing the accuracy and security of these systems.One of the key developments is the integration of d... The field of biometric identification has seen significant advancements over the years,with research focusing on enhancing the accuracy and security of these systems.One of the key developments is the integration of deep learning techniques in biometric systems.However,despite these advancements,certain challenges persist.One of the most significant challenges is scalability over growing complexity.Traditional methods either require maintaining and securing a growing database,introducing serious security challenges,or relying on retraining the entiremodelwhen new data is introduced-a process that can be computationally expensive and complex.This challenge underscores the need for more efficient methods to scale securely.To this end,we introduce a novel approach that addresses these challenges by integrating multimodal biometrics,cancelable biometrics,and incremental learning techniques.This work is among the first attempts to seamlessly incorporate deep cancelable biometrics with dynamic architectural updates,applied incrementally to the deep learning model as new users are enrolled,achieving high performance with minimal catastrophic forgetting.By leveraging a One-Dimensional Convolutional Neural Network(1D-CNN)architecture combined with a hybrid incremental learning approach,our system achieves high recognition accuracy,averaging 98.98% over incrementing datasets,while ensuring user privacy through cancelable templates generated via a pre-trained CNN model and random projection.The approach demonstrates remarkable adaptability,utilizing the least intrusive biometric traits like facial features and fingerprints,ensuring not only robust performance but also long-term serviceability. 展开更多
关键词 Incremental learning personal identification cancelablemulti-biometrics pattern recognition security deep learning cyber-attacks transfer learning random projection catastrophic forgetting
在线阅读 下载PDF
Minimum Number of Load Increments in Second-Order Elastic Analyses of Steel Frames
17
作者 Nadine Faramawi Barry T.Rosson 《Journal of Civil Engineering and Architecture》 2025年第11期523-527,共5页
A relationship was discovered between the amplification factor and the number of load increments that are needed to limit the relative error to one percent in second-order elastic analyses with a predictor-corrector s... A relationship was discovered between the amplification factor and the number of load increments that are needed to limit the relative error to one percent in second-order elastic analyses with a predictor-corrector solution scheme.Previous research by the authors proposed a design equation to determine the required minimum number of load increments based on an evaluation of the elastic critical buckling load ratio.Further research has shown that an approximate amplification factor equation that is based on the B2 multiplier equation produces similar results when the amplification factor is less than approximately four.Eleven moment frames are used to verify the use of the new approximate amplification factor in the proposed design equation. 展开更多
关键词 Nonlinear geometric analysis amplification factor load increment structural frame
在线阅读 下载PDF
Global workspace theory-based cognitive architecture for robots
18
作者 HUANG Wenjie CANGELOSI Angelo CHELLA Antonio 《宁波大学学报(理工版)》 2025年第2期49-58,共10页
This paper adopts the Global Workspace Theory as a neuro-scientifically plausible theory for developing conscious cognitive architecture.The Global Workspace Theory’s compatibility with the working mechanisms underne... This paper adopts the Global Workspace Theory as a neuro-scientifically plausible theory for developing conscious cognitive architecture.The Global Workspace Theory’s compatibility with the working mechanisms underneath human brains is enhanced by the implementation of different cognitive features based on this framework.Amongst the topics in the literature for intelligent systems,we start with attention,memory and learning mechanisms,and corresponding experiments are summarized here.We also discuss how other topics of cognitive robotics could be developed based on these three basic components,and their correlations.This provides a foundation for future long-term development of cognitive architectures of cognitive robots.The research in this paper follows the incremental research pathway for the architecture implementation,which is consistent with the Biologically Inspired Cognitive Architecture roadmap. 展开更多
关键词 Global Workspace Theory cognitive architecture INCREMENTAL biologically inspired cognitive architecture
在线阅读 下载PDF
A new test method for friction in incremental sheet forming
19
作者 Guang-can YANG Da-wei ZHANG +1 位作者 Chong TIAN Sheng-dun ZHAO 《Transactions of Nonferrous Metals Society of China》 2025年第12期3985-4006,共22页
An analytical model for contact area and contact stress considering the loading history in incremental sheet forming(ISF)was established.Then,by integrating with the directional characteristics of friction force and h... An analytical model for contact area and contact stress considering the loading history in incremental sheet forming(ISF)was established.Then,by integrating with the directional characteristics of friction force and horizontal force in the process,a friction test method reflecting the forming characteristics of ISF was proposed.Friction coefficients during the forming processes of parts with different wall angles were measured under various plane curves,process paths,and lubrication conditions.Furthermore,the accuracy of the analytical model,as well as the measured friction coefficients and their variation trends,was verified through comparative analysis with experimental results,simulation data,and outcomes from other existing models.The results indicate that the influence of the plane curve characteristics and process paths of parts on the friction condition is not significant.Under the lubrication conditions of L-HM46 oil,MoS_(2)grease,graphite powder,and dry friction,the friction coefficient shows a gradually increasing trend.Notably,when the wall angle is≤40°,the friction coefficient remains relatively constant;however,when the wall angle exceeds 40°,the friction coefficient increases progressively. 展开更多
关键词 incremental sheet forming friction test method contact area friction coefficient forming force
在线阅读 下载PDF
上一页 1 2 32 下一页 到第
使用帮助 返回顶部