期刊文献+
共找到911,511篇文章
< 1 2 250 >
每页显示 20 50 100
Evolution of Smart Parks and Development of Park Information Modeling(PIM):Concept and Design Application 被引量:2
1
作者 YANG Kaixian ZHEN Feng ZHANG Shanqi 《Chinese Geographical Science》 2025年第5期982-998,共17页
With the development of smart cities and smart technologies,parks,as functional units of the city,are facing smart transformation.The development of smart parks can help address challenges of technology integration wi... With the development of smart cities and smart technologies,parks,as functional units of the city,are facing smart transformation.The development of smart parks can help address challenges of technology integration within urban spaces and serve as testbeds for exploring smart city planning and governance models.Information models facilitate the effective integration of technology into space.Building Information Modeling(BIM)and City Information Modeling(CIM)have been widely used in urban construction.However,the existing information models have limitations in the application of the park,so it is necessary to develop an information model suitable for the park.This paper first traces the evolution of park smart transformation,reviews the global landscape of smart park development,and identifies key trends and persistent challenges.Addressing the particularities of parks,the concept of Park Information Modeling(PIM)is proposed.PIM leverages smart technologies such as artificial intelligence,digital twins,and collaborative sensing to help form a‘space-technology-system’smart structure,enabling systematic management of diverse park spaces,addressing the deficiency in park-level information models,and aiming to achieve scale articulation between BIM and CIM.Finally,through a detailed top-level design application case study of the Nanjing Smart Education Park in China,this paper illustrates the translation process of the PIM concept into practice,showcasing its potential to provide smart management tools for park managers and enhance services for park stakeholders,although further empirical validation is required. 展开更多
关键词 smart park smart city Park Information modeling(PIM) smart technology Building Information modeling(BIM) City Information modeling(CIM)
在线阅读 下载PDF
Multiscalar Geomorphometric Generalization for Soil-Landscape Modeling by Random Forest: A Case Study in the Eastern Amazon
2
作者 Cauan Ferreira Araújo Raimundo Cosme de Oliveira Junior Troy Patrick Beldini 《Journal of Geographic Information System》 2021年第4期434-451,共18页
Multiscalar topography influence on soil distribution has a complex pattern that is related to overlay of pedological processes which occurred at different times, and these driving forces are correlated with many geom... Multiscalar topography influence on soil distribution has a complex pattern that is related to overlay of pedological processes which occurred at different times, and these driving forces are correlated with many geomorphologic scales. In this sense, the present study tested the hypothesis whether multiscale geomorphometric generalized covariables can improve pedometric modeling. To achieve this goal, this case study applied the Random Forest algorithm to a multiscale geomorphometric database to predict soil surface attributes. The study area is in phanerozoic sedimentary basins, in the Alter do Ch<span style="white-space:nowrap;">&#227;</span>o geological formation, Eastern Amazon, Brazil. The multiscale geomorphometric generalization was applied at general and specific geomorphometric covariables, producing groups for each scale combination. The modeling was run using Random Forest for A-horizon thickness, pH, silt and sand content. For model evaluation, visual analysis of digital maps, metrics of forest structures and effect of variables on prediction were used. For evaluation of soil textural classifications, the confusion matrix with a Kappa index, and the user’s and producer’s accuracies were employed. The geomorphometry generalization tends to smooth curvatures and produces identifiable geomorphic representations at sub-watershed and watershed levels. The forest structures and effect of variables on prediction are in agreement with pedological knowledge. The multiscale geomorphometric generalized covariables improved accuracy metrics of soil surface texture classification, with the Kappa Index going from 43% to 62%. Therefore, it can be argued that topography influences soil distribution at combined coarser spatial scales and is able to predict soil particle size contents in the studied watershed. Future development of the multiscale geomorphometric generalization framework could include generalization methods concerning preservation of features, landform classification adaptable at multiple scales. 展开更多
关键词 Digital Soil Mapping Upscaling Machine Learning Random Forest Algorithm Multiscale Geomorphometric generalization
在线阅读 下载PDF
A Multi-Level Semantic Constraint Approach for Highway Tunnel Scene Twin Modeling 被引量:1
3
作者 LI Yufei XIE Yakun +3 位作者 CHEN Mingzhen ZHAO Yaoji TU Jiaxing HU Ya 《Journal of Geodesy and Geoinformation Science》 2025年第2期37-56,共20页
As a key node of modern transportation network,the informationization management of road tunnels is crucial to ensure the operation safety and traffic efficiency.However,the existing tunnel vehicle modeling methods ge... As a key node of modern transportation network,the informationization management of road tunnels is crucial to ensure the operation safety and traffic efficiency.However,the existing tunnel vehicle modeling methods generally have problems such as insufficient 3D scene description capability and low dynamic update efficiency,which are difficult to meet the demand of real-time accurate management.For this reason,this paper proposes a vehicle twin modeling method for road tunnels.This approach starts from the actual management needs,and supports multi-level dynamic modeling from vehicle type,size to color by constructing a vehicle model library that can be flexibly invoked;at the same time,semantic constraint rules with geometric layout,behavioral attributes,and spatial relationships are designed to ensure that the virtual model matches with the real model with a high degree of similarity;ultimately,the prototype system is constructed and the case region is selected for the case study,and the dynamic vehicle status in the tunnel is realized by integrating real-time monitoring data with semantic constraints for precise virtual-real mapping.Finally,the prototype system is constructed and case experiments are conducted in selected case areas,which are combined with real-time monitoring data to realize dynamic updating and three-dimensional visualization of vehicle states in tunnels.The experiments show that the proposed method can run smoothly with an average rendering efficiency of 17.70 ms while guaranteeing the modeling accuracy(composite similarity of 0.867),which significantly improves the real-time and intuitive tunnel management.The research results provide reliable technical support for intelligent operation and emergency response of road tunnels,and offer new ideas for digital twin modeling of complex scenes. 展开更多
关键词 highway tunnel twin modeling multi-level semantic constraints tunnel vehicles multidimensional modeling
在线阅读 下载PDF
Stress-Induced Endogenous Cannabinoid Signaling Contributes to Fear Generalization
4
作者 Yanan Yue Xia Zhang Yuan Dong 《Neuroscience Bulletin》 2025年第6期1123-1126,共4页
The phenomenon of fear memory generalization can be defined as the expansion of an individual's originally specific fear responses to a similar yet genuinely harmless stimulus or situation subsequent to the occurr... The phenomenon of fear memory generalization can be defined as the expansion of an individual's originally specific fear responses to a similar yet genuinely harmless stimulus or situation subsequent to the occurrence of a traumatic event[1].Fear generalization within the normal range represents an adaptive evolutionary mechanism to facilitate prompt reactions to potential threats and to enhance the likelihood of survival. 展开更多
关键词 STRESS adaptive mechanism originally specific fear responses fear memory generalization endogenous cannabinoid signaling fear generalization adaptive evolutionary mechanism enhance likelihood survival
原文传递
Electrical and aging modeling of PEM water electrolyzers for sustainable hydrogen production:Insights into behavior,degradation,and reliability
5
作者 Haniyeh Marefat Francois Auger +1 位作者 Jean-Christophe Olivier Mohammed Rharda 《Global Energy Interconnection》 2025年第4期537-553,共17页
Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Stat... Proton Exchange Membrane Water Electrolyzers(PEMWE)are efficient and sustainable hydrogen production devices.This article analyzes their static and dynamic electrical models integrated with degradation mechanisms.Static models reveal steady-state behavior,while dynamic models capture transient responses to input variations.The developed modeling approach combines the activation and diffusion phenomena,resulting in a novel PEMWE model that closely reflects real-world conditions and enables fast simulations.The electrical model is integrated with the aging model through two key ratios,surface degradation ratio and membrane degradation ratio,which characterize degradation mechanisms affecting electrode and membrane performance.The linear model using second-order Taylor approximation enables the development of a diagnosis approach that can contribute to estimating the remaining useful life of PEMWEs.By associating aging models with electrical models through the proposed ratios,a deeper understanding is achieved regarding how degra-dation phenomena evolve and influence electrolyzer efficiency and durability.The integrated framework enables predictive maintenance strategies,making it valuable for industrial hydrogen production applications. 展开更多
关键词 PEM water electrolyzer Polarization curve Electrical modeling Linear polarization curve Aging modeling DEGRADATION RELIABILITY Hydrogen production Maximum production point
在线阅读 下载PDF
Optimizing CNN Architectures for Face Liveness Detection:Performance,Efficiency,and Generalization across Datasets 被引量:1
6
作者 Smita Khairnar Shilpa Gite +2 位作者 Biswajeet Pradhan Sudeep D.Thepade Abdullah Alamri 《Computer Modeling in Engineering & Sciences》 2025年第6期3677-3707,共31页
Face liveness detection is essential for securing biometric authentication systems against spoofing attacks,including printed photos,replay videos,and 3D masks.This study systematically evaluates pre-trained CNN model... Face liveness detection is essential for securing biometric authentication systems against spoofing attacks,including printed photos,replay videos,and 3D masks.This study systematically evaluates pre-trained CNN models—DenseNet201,VGG16,InceptionV3,ResNet50,VGG19,MobileNetV2,Xception,and InceptionResNetV2—leveraging transfer learning and fine-tuning to enhance liveness detection performance.The models were trained and tested on NUAA and Replay-Attack datasets,with cross-dataset generalization validated on SiW-MV2 to assess real-world adaptability.Performance was evaluated using accuracy,precision,recall,FAR,FRR,HTER,and specialized spoof detection metrics(APCER,NPCER,ACER).Fine-tuning significantly improved detection accuracy,with DenseNet201 achieving the highest performance(98.5%on NUAA,97.71%on Replay-Attack),while MobileNetV2 proved the most efficient model for real-time applications(latency:15 ms,memory usage:45 MB,energy consumption:30 mJ).A statistical significance analysis(paired t-tests,confidence intervals)validated these improvements.Cross-dataset experiments identified DenseNet201 and MobileNetV2 as the most generalizable architectures,with DenseNet201 achieving 86.4%accuracy on Replay-Attack when trained on NUAA,demonstrating robust feature extraction and adaptability.In contrast,ResNet50 showed lower generalization capabilities,struggling with dataset variability and complex spoofing attacks.These findings suggest that MobileNetV2 is well-suited for low-power applications,while DenseNet201 is ideal for high-security environments requiring superior accuracy.This research provides a framework for improving real-time face liveness detection,enhancing biometric security,and guiding future advancements in AI-driven anti-spoofing techniques. 展开更多
关键词 Face liveness detection cross-dataset generalization real-time face authentication transfer learning DenseNet201 VGG16 InceptionV3 deep learning
在线阅读 下载PDF
Influence of different data selection criteria on internal geomagnetic field modeling 被引量:4
7
作者 HongBo Yao JuYuan Xu +3 位作者 Yi Jiang Qing Yan Liang Yin PengFei Liu 《Earth and Planetary Physics》 2025年第3期541-549,共9页
Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these i... Earth’s internal core and crustal magnetic fields,as measured by geomagnetic satellites like MSS-1(Macao Science Satellite-1)and Swarm,are vital for understanding core dynamics and tectonic evolution.To model these internal magnetic fields accurately,data selection based on specific criteria is often employed to minimize the influence of rapidly changing current systems in the ionosphere and magnetosphere.However,the quantitative impact of various data selection criteria on internal geomagnetic field modeling is not well understood.This study aims to address this issue and provide a reference for constructing and applying geomagnetic field models.First,we collect the latest MSS-1 and Swarm satellite magnetic data and summarize widely used data selection criteria in geomagnetic field modeling.Second,we briefly describe the method to co-estimate the core,crustal,and large-scale magnetospheric fields using satellite magnetic data.Finally,we conduct a series of field modeling experiments with different data selection criteria to quantitatively estimate their influence.Our numerical experiments confirm that without selecting data from dark regions and geomagnetically quiet times,the resulting internal field differences at the Earth’s surface can range from tens to hundreds of nanotesla(nT).Additionally,we find that the uncertainties introduced into field models by different data selection criteria are significantly larger than the measurement accuracy of modern geomagnetic satellites.These uncertainties should be considered when utilizing constructed magnetic field models for scientific research and applications. 展开更多
关键词 Macao Science Satellite-1 SWARM geomagnetic field modeling data selection core field crustal field
在线阅读 下载PDF
3D crustal density modeling of Egypt using GOCE satellite gravity data and seismic integration 被引量:1
8
作者 Moataz Sayed Mohamed Sobh +2 位作者 Salah Saleh Amal Othman Ahmed Elmahmoudi 《Earthquake Science》 2025年第2期110-125,共16页
A 3D crustal model was constructed using a combination of cutting-edge techniques,which were integrated to provide a density model for Egypt and address the sporadic distribution of seismic data.These techniques inclu... A 3D crustal model was constructed using a combination of cutting-edge techniques,which were integrated to provide a density model for Egypt and address the sporadic distribution of seismic data.These techniques include obtaining gravity data from the Gravity Field and Steady-State Ocean Circulation Explorer(GOCE),creating seismic profiles,analyzing the receiver functions of seismic data,obtaining information from boreholes,and providing geological interpretations.GOCE satellite gravity data were processed to construct a preliminary model based on nonlinear inversions of the data.A regional crustal thickness model was developed using receiver functions,seismic refraction profiles,and geological insights.The inverted model was validated using borehole data and compared with seismic estimates.The model exhibited strong consistency and revealed a correlation between crustal thickness,geology,and tectonics of Egypt.It showed that the shallowest depths of the Moho are located in the north along the Mediterranean Sea and in the eastern part along the Red Sea,reflecting an oceanic plate with a thin,high-density crust.The deepest Moho depths are located in the southwestern part of Egypt,Red Sea coastal mountains,and Sinai Peninsula.The obtained 3D model of crustal thickness provided finely detailed Moho depth estimates that aligned closely with geology and tectonic characteristics of Egypt,contributing valuable insights into the subsurface structure and tectonic processes of region. 展开更多
关键词 GOCE satellite gravity Moho depth crustal modeling gravity inversion
在线阅读 下载PDF
Phase field modeling of the aspect ratio dependent functional properties of NiTi shape memory alloys with different grain sizes 被引量:1
9
作者 Bo Xu Beihai Huang +1 位作者 Chong Wang Qingyuan Wang 《Acta Mechanica Sinica》 2025年第1期22-41,共20页
It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size... It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size(grain size,GS)or the external size(geometric size).The coupled effect of GS and geometric size on the functional properties has not been clearly understood yet.In this work,the super-elasticity,one-way,and stress-assisted two-way shape memory effects of the polycrystalline NiTi SMAs with different aspect ratios(length/width for the gauge section)and different GSs are investigated based on the phase field method.The coupled effect of the aspect ratio and GS on the functional properties is adequately revealed.The simulated results indicate that when the aspect ratio is lower than about 4:1,the stress biaxiality and stress heterogeneity in the gauge section of the sample become more and more obvious with decreasing the aspect ratio,which can significantly influence the microstructure evolution in the process involving external stress.Therefore,the corresponding functional property is strongly dependent on the aspect ratio.With decreasing the GS and the aspect ratio(to be lower than 4:1),both the aspect ratio and GS can affect the MT or martensite reorientation in each grain and the interaction among grains.Thus,due to the strong internal constraint(i.e.,the constraint of grain boundary)and the external constraint(i.e.,the constraint of geometric boundary),the capabilities of the functional properties of NiTi SMAs are gradually weakened and highly dependent on these two factors. 展开更多
关键词 Phase field modeling NITI Aspect ratio Grain size Functional property
原文传递
A Nonspherical Cloud Scattering Database Using Aggregates of Roughened Bullet Rosettes Model for the Advanced Radiative Transfer Modeling System(ARMS) 被引量:1
10
作者 Ziyue HUANG Hanyu LU +4 位作者 Ziqiang MA Yining SHI Yang HAN Hao HU Jun YANG 《Advances in Atmospheric Sciences》 2025年第7期1483-1498,共16页
Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up ... Accurate satellite data assimilation under all-sky conditions requires enhanced parameterization of scattering properties for frozen hydrometeors in clouds.This study aims to develop a nonspherical scattering look-up table that contains the optical properties of five hydrometeor types—rain,cloud water,cloud ice,graupel,and snow—for the Advanced Radiative Transfer Modeling System(ARMS)at frequencies below 220 GHz.The discrete dipole approximation(DDA)method is employed to compute the single-scattering properties of solid cloud particles,modeling these particles as aggregated roughened bullet rosettes.The bulk optical properties of the cloud layer are derived by integrating the singlescattering properties with a modified Gamma size distribution,specifically for distributions with 18 effective radii.The bulk phase function is then projected onto a series of generalized spherical functions,applying the delta-M method for truncation.The results indicate that simulations using the newly developed nonspherical scattering look-up table exhibit significant consistency with observations under deep convection conditions.In contrast,assuming spherical solid cloud particles leads to excessive scattering at mid-frequency channels and insufficient scattering at high-frequency channels.This improvement in radiative transfer simulation accuracy for cloudy conditions will better support the assimilation of allsky microwave observations into numerical weather prediction models.·Frozen cloud particles were modeled as aggregates of bullet rosettes and the optical properties at microwave range were computed by DDA.·A complete process and technical details for constructing a look-up table of ARMS are provided.·The ARMS simulations generally show agreement with observations of MWTS and MWHS under typhoon conditions using the new look-up table. 展开更多
关键词 nonspherical particles scattering look-up table discrete dipole approximation Advanced Radiative Transfer modeling System
在线阅读 下载PDF
Unsteady aerodynamic modeling and analysis of aircraft model in multi-DOF coupling maneuvers at high angles of attack with attention mechanism 被引量:1
11
作者 Wenzhao DONG Xiaoguang WANG +1 位作者 Dongbo HAN Qi LIN 《Chinese Journal of Aeronautics》 2025年第6期349-361,共13页
Unsteady aerodynamic characteristics at high angles of attack are of great importance to the design and development of advanced fighter aircraft, which are characterized by post-stall maneuverability with multiple Deg... Unsteady aerodynamic characteristics at high angles of attack are of great importance to the design and development of advanced fighter aircraft, which are characterized by post-stall maneuverability with multiple Degrees-of-Freedom(multi-DOF) and complex flow field structure.In this paper, a special kind of cable-driven parallel mechanism is firstly utilized as a new suspension method to conduct unsteady dynamic wind tunnel tests at high angles of attack, thereby providing experimental aerodynamic data. These tests include a wide range of multi-DOF coupled oscillatory motions with various amplitudes and frequencies. Then, for aerodynamic modeling and analysis, a novel data-driven Feature-Level Attention Recurrent neural network(FLAR) is proposed. This model incorporates a specially designed feature-level attention module that focuses on the state variables affecting the aerodynamic coefficients, thereby enhancing the physical interpretability of the aerodynamic model. Subsequently, spin maneuver simulations, using a mathematical model as the baseline, are conducted to validate the effectiveness of the FLAR. Finally, the results on wind tunnel data reveal that the FLAR accurately predicts aerodynamic coefficients, and observations through the visualization of attention scores identify the key state variables that affect the aerodynamic coefficients. It is concluded that the proposed FLAR enhances the interpretability of the aerodynamic model while achieving good prediction accuracy and generalization capability for multi-DOF coupling motion at high angles of attack. 展开更多
关键词 Unsteady aerodynamics Aerodynamic modeling High angle of attack Wind tunnel test Attention mechanism
原文传递
Modeling of a Parabolic Cylindrical Solar Concentrator
12
作者 Bati Ernest Boya Bi Kpeusseu Angeline Kouambla Epse Yeo +1 位作者 Ekoun Paul Magloire Koffi Prosper Gbaha 《Open Journal of Applied Sciences》 2025年第1期53-69,共17页
This work aims at the mathematical modeling of a parabolic trough concentrator, the numerical resolution of the resulting equation, as well as the simulation of the heat transfer fluid heating process. To do this, a t... This work aims at the mathematical modeling of a parabolic trough concentrator, the numerical resolution of the resulting equation, as well as the simulation of the heat transfer fluid heating process. To do this, a thermal balance was established for the heat transfer fluid, the absorber and the glass. This allowed us to establish an equation system whose resolution was done by the finite difference method. Then, a computer program was developed to simulate the temperatures of the heat transfer fluid, the absorber tube and the glass as a function of time and space. The numerical resolution made it possible to obtain the temperatures of the heat transfer fluid, the absorber and the glass. The simulation of the fluid heating process was done in one-hour time steps, from six in the morning to six in the afternoon. The results obtained show that the temperature difference between the inlet and the outlet of the sensor is very significant. These results obtained, regarding the variation of the temperatures of the heat transfer fluid, the absorber and the glass, as well as the powers and efficiency of the parabolic trough concentrator and various factors, allow for the improvement of the performances of our prototype. 展开更多
关键词 modeling SIMULATION Parabolic Trough Concentrator Heat Transfer Fluid TEMPERATURE
在线阅读 下载PDF
Physical Modeling of Reconfigurable Intelligent Surface for Channel Modeling
13
作者 MiaoWei Dou Jianwu +1 位作者 Cui Yijun Yang Zhenyu 《China Communications》 2025年第2期128-142,共15页
In this paper,a physical model of RIS of bistatic polarized radar cross section is derived starting from the Stratton-Chu equations under the assumptions of physical optics,PEC,far field and rectangular RIS element.In... In this paper,a physical model of RIS of bistatic polarized radar cross section is derived starting from the Stratton-Chu equations under the assumptions of physical optics,PEC,far field and rectangular RIS element.In the context of important physical characteristics of the backscattering polarization of RIS,the modeling of the RIS wireless channel requires a tradeoff between complexity and accuracy,as well as usability and simplicity.For channel modeling of RIS systems,RIS is modelled as multi-equivalent virtual base stations(BSs)induced by multi polarized electromagnetic waves from different incident directions.The comparison between test and simulation results demonstrates that the proposed algorithm effectively captures the key characteristics of the general RIS element polarization physical model and provides accurate results. 展开更多
关键词 channel modeling map-based hybrid channel model polarized model Reconfigurable intelligent surface(RIS)
在线阅读 下载PDF
A review of multiscale numerical modeling of rock mechanics and rock engineering
14
作者 Xindong Wei Zhe Li Gaofeng Zhao 《Deep Underground Science and Engineering》 2025年第3期382-405,共24页
Rock is geometrically and mechanically multiscale in nature,and the traditional phenomenological laws at the macroscale cannot render a quantitative relationship between microscopic damage of rocks and overall rock st... Rock is geometrically and mechanically multiscale in nature,and the traditional phenomenological laws at the macroscale cannot render a quantitative relationship between microscopic damage of rocks and overall rock structural degradation.This may lead to problems in the evaluation of rock structure stability and safe life.Multiscale numerical modeling is regarded as an effective way to gain insight into factors affecting rock properties from a cross-scale view.This study compiles the history of theoretical developments and numerical techniques related to rock multiscale issues according to different modeling architectures,that is,the homogenization theory,the hierarchical approach,and the concurrent approach.For these approaches,their benefits,drawbacks,and application scope are underlined.Despite the considerable attempts that have been made,some key issues still result in multiple challenges.Therefore,this study points out the perspectives of rock multiscale issues so as to provide a research direction for the future.The review results show that,in addition to numerical techniques,for example,high-performance computing,more attention should be paid to the development of an advanced constitutive model with consideration of fine geometrical descriptions of rock to facilitate solutions to multiscale problems in rock mechanics and rock engineering. 展开更多
关键词 constitutive model multiscale modeling numerical method ROCK
原文传递
Modeling of Precipitation over Africa:Progress,Challenges,and Prospects
15
作者 A.A.AKINSANOLA C.N.WENHAJI +21 位作者 R.BARIMALALA P.-A.MONERIE R.D.DIXON A.T.TAMOFFO M.O.ADENIYI V.ONGOMA I.DIALLO M.GUDOSHAVA C.M.WAINWRIGHT R.JAMES K.C.SILVERIO A.FAYE S.S.NANGOMBE M.W.POKAM D.A.VONDOU N.C.G.HART I.PINTO M.KILAVI S.HAGOS E.N.RAJAGOPAL R.K.KOLLI S.JOSEPH 《Advances in Atmospheric Sciences》 2026年第1期59-86,共28页
In recent years,there has been an increasing need for climate information across diverse sectors of society.This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and cha... In recent years,there has been an increasing need for climate information across diverse sectors of society.This demand has arisen from the necessity to adapt to and mitigate the impacts of climate variability and change.Likewise,this period has seen a significant increase in our understanding of the physical processes and mechanisms that drive precipitation and its variability across different regions of Africa.By leveraging a large volume of climate model outputs,numerous studies have investigated the model representation of African precipitation as well as underlying physical processes.These studies have assessed whether the physical processes are well depicted and whether the models are fit for informing mitigation and adaptation strategies.This paper provides a review of the progress in precipitation simulation overAfrica in state-of-the-science climate models and discusses the major issues and challenges that remain. 展开更多
关键词 RAINFALL MONSOON climate modeling CORDEX CMIP6 convection-permitting models
在线阅读 下载PDF
DDIRNet:robust radar emitter recognition via single domain generalization
16
作者 WU Honglin LI Xueqiong +2 位作者 HUANG Junjie JIN Ruochun TANG Yuhua 《Journal of Systems Engineering and Electronics》 2025年第2期397-404,共8页
Automatically recognizing radar emitters from com-plex electromagnetic environments is important but non-trivial.Moreover,the changing electromagnetic environment results in inconsistent signal distribution in the rea... Automatically recognizing radar emitters from com-plex electromagnetic environments is important but non-trivial.Moreover,the changing electromagnetic environment results in inconsistent signal distribution in the real world,which makes the existing approaches perform poorly for recognition tasks in different scenes.In this paper,we propose a domain generaliza-tion framework is proposed to improve the adaptability of radar emitter signal recognition in changing environments.Specifically,we propose an end-to-end denoising based domain-invariant radar emitter recognition network(DDIRNet)consisting of a denoising model and a domain invariant representation learning model(IRLM),which mutually benefit from each other.For the signal denoising model,a loss function is proposed to match the feature of the radar signals and guarantee the effectiveness of the model.For the domain invariant representation learning model,contrastive learning is introduced to learn the cross-domain feature by aligning the source and unseen domain distri-bution.Moreover,we design a data augmentation method that improves the diversity of signal data for training.Extensive experiments on classification have shown that DDIRNet achieves up to 6.4%improvement compared with the state-of-the-art radar emitter recognition methods.The proposed method pro-vides a promising direction to solve the radar emitter signal recognition problem. 展开更多
关键词 radar emitter recognition domain generalization DENOISING contrastive learning data augmentation.
在线阅读 下载PDF
Modeling the Conversion of Forest Land to Other Types of Occupation Due to Urban Growth in Five Forest Towns in the Congo Basin
17
作者 Stoffenne Malonga Binsangou Suspense Averti Ifo Benoit Mertens 《Open Journal of Ecology》 2025年第1期43-64,共22页
The conversion of forest land to other types of land cover is one of the major issues in the global fight against climate change. Understanding the direct and indirect factors of these conversions from local studies i... The conversion of forest land to other types of land cover is one of the major issues in the global fight against climate change. Understanding the direct and indirect factors of these conversions from local studies in the tropics is essential to project the future impact of human activities on the preservation of tropical forests in general and the forests of the Republic of Congo in particular. This study, conducted in five localities with different socioeconomic contexts in the Republic of Congo, aims to analyze the variability of drivers of deforestation and forest degradation linked to urbanization in the Congo Basin. Using a series of land cover maps from the years 1986, 2003 and 2019 for the cities of Ouesso, Pokola, Ngombe, Impfondo and Dongou, as well as field data and socio-economic information collected from local and central administrations, a unique model has been developed to understand the explanatory patterns of forest loss. Deforestation around urban centers is mainly due to urban agriculture due to population growth, as well as the spatial expansion of cities, which have a major impact on the stability and integrity of forests. Shifting agriculture is the main direct cause of deforestation and forest degradation, representing 48% of the total sample, followed by the collection of wood fuel (22%), the collection of construction wood (19%), illegal logging (6%) and urban expansion (5%). Forecasts indicate that forest loss around major cities will increase by 487, 20 ha to 5266, 73 ha by 2050 compared to the base year of 2019. This study highlights the need for a new system of land management and poverty alleviation of local populations to ensure the stability of the Congo Basin tropical forests around large and small African cities. 展开更多
关键词 DEFORESTATION Degradation modeling Congo Basin Land Use Change LANDSAT Strong Points
在线阅读 下载PDF
Semi-supervised cardiac magnetic resonance image segmentation based on domain generalization
18
作者 SHAO Hong HOU Jinyang CUI Wencheng 《High Technology Letters》 2025年第1期41-52,共12页
In the realm of medical image segmentation,particularly in cardiac magnetic resonance imaging(MRI),achieving robust performance with limited annotated data is a significant challenge.Performance often degrades when fa... In the realm of medical image segmentation,particularly in cardiac magnetic resonance imaging(MRI),achieving robust performance with limited annotated data is a significant challenge.Performance often degrades when faced with testing scenarios from unknown domains.To address this problem,this paper proposes a novel semi-supervised approach for cardiac magnetic resonance image segmentation,aiming to enhance predictive capabilities and domain generalization(DG).This paper establishes an MT-like model utilizing pseudo-labeling and consistency regularization from semi-supervised learning,and integrates uncertainty estimation to improve the accuracy of pseudo-labels.Additionally,to tackle the challenge of domain generalization,a data manipulation strategy is introduced,extracting spatial and content-related information from images across different domains,enriching the dataset with a multi-domain perspective.This papers method is meticulously evaluated on the publicly available cardiac magnetic resonance imaging dataset M&Ms,validating its effectiveness.Comparative analyses against various methods highlight the out-standing performance of this papers approach,demonstrating its capability to segment cardiac magnetic resonance images in previously unseen domains even with limited annotated data. 展开更多
关键词 SEMI-SUPERVISED domain generalization(DG) cardiac magnetic resonance image segmentation
在线阅读 下载PDF
Modeling the Cardiovascular System for the Simulation of Special Cases of Pulmonary Hypertension
19
作者 Jefferson Sidoine Tadjonang Tegne René Thierry Djoumessi François Beceau Pelap 《Open Journal of Applied Sciences》 2025年第1期202-219,共18页
This study examines hemodynamic behavior in particular cases of pulmonary hypertension without treatment. Pulmonary hypertension represents an anomalous hemodynamic state and is characterized by an excessively high bl... This study examines hemodynamic behavior in particular cases of pulmonary hypertension without treatment. Pulmonary hypertension represents an anomalous hemodynamic state and is characterized by an excessively high blood pressure in the pulmonary artery. To simulate the hemodynamic abnormalities in pulmonary hypertension under different causes and pathologies, we construct a localized parameter circuit model governed by nonlinear ordinary derivative equations of the human circulatory system. Thus, two special cases are considered, namely pulmonary the artery stenosis and the left ventricular diastolic dysfunction. For each case of pulmonary hypertension development, we determine the relationships between blood pressure and chamber and vessel pressure-volume. When the pulmonary hypertension is due to pulmonary artery stenosis, it appears that the right ventricular pressure increases up to 90 mm Hg, likewise the rise in pulmonary artery resistance induces direct increment in pulmonary artery pressure. However, when the pulmonary hypertension is due to left ventricular diastolic dysfunction, we note that the left atrial pressure and the pulmonary vein pressure augment, leading to the growth of the pulmonary artery blood pressure. The established results within this paper are useful for understanding the hemodynamic mechanism of particular pulmonary hypertension. 展开更多
关键词 Pulmonary Hypertension Hemodynamic modeling Pulmonary Artery Stenosis Left Ventricular Diastolic Dysfunction
暂未订购
Intelligent modeling method for OV models in DoDAF2.0 based on knowledge graph
20
作者 ZHANG Yue JIANG Jiang +3 位作者 YANG Kewei WANG Xingliang XU Chi LI Minghao 《Journal of Systems Engineering and Electronics》 2025年第1期139-154,共16页
Architecture framework has become an effective method recently to describe the system of systems(SoS)architecture,such as the United States(US)Department of Defense Architecture Framework Version 2.0(DoDAF2.0).As a vi... Architecture framework has become an effective method recently to describe the system of systems(SoS)architecture,such as the United States(US)Department of Defense Architecture Framework Version 2.0(DoDAF2.0).As a viewpoint in DoDAF2.0,the operational viewpoint(OV)describes operational activities,nodes,and resource flows.The OV models are important for SoS architecture development.However,as the SoS complexity increases,constructing OV models with traditional methods exposes shortcomings,such as inefficient data collection and low modeling standards.Therefore,we propose an intelligent modeling method for five OV models,including operational resource flow OV-2,organizational relationships OV-4,operational activity hierarchy OV-5a,operational activities model OV-5b,and operational activity sequences OV-6c.The main idea of the method is to extract OV architecture data from text and generate interoperable OV models.First,we construct the OV meta model based on the DoDAF2.0 meta model(DM2).Second,OV architecture named entities is recognized from text based on the bidirectional long short-term memory and conditional random field(BiLSTM-CRF)model.And OV architecture relationships are collected with relationship extraction rules.Finally,we define the generation rules for OV models and develop an OV modeling tool.We use unmanned surface vehicles(USV)swarm target defense SoS architecture as a case to verify the feasibility and effectiveness of the intelligent modeling method. 展开更多
关键词 system of systems(SoS)architecture operational viewpoint(OV)model meta model bidirectional long short-term memory and conditional random field(BiLSTM-CRF) model generation systems modeling language
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部