The free-surface vortex is a rotational flow phenomenon characterized by two-phase coupling,formed by the rupture of surface fluid in the final stage of discharge.It is a significant concept with broad applications in...The free-surface vortex is a rotational flow phenomenon characterized by two-phase coupling,formed by the rupture of surface fluid in the final stage of discharge.It is a significant concept with broad applications in engineering fields like metallurgy and hydraulics.The basic concepts and characteristics of free-surface vortices were introduced,and their hazards in various fields were discussed.The development of theoretical and numerical models over recent decades was reviewed,and the factors affecting vortex formation and existing suppression methods were outlined.Finally,the key challenges and focus areas on the study of free-surface vortex were summarized.With the ongoing advancements in computational fluid dynamics and experimental technology,research on free-surface vortices will become more in depth and precise.Additionally,interdisciplinary cooperation and technological innovation are expected to achieve precise control and optimal design of free-surface vortices,offering more efficient and sustainable solutions for metallurgy and related engineering fields.展开更多
Multiple suppression is an important element of marine seismic data processing.Intelligent suppression of multiples us-ing artificial intelligence reduces labor costs,minimizes dependence on unknown prior information,...Multiple suppression is an important element of marine seismic data processing.Intelligent suppression of multiples us-ing artificial intelligence reduces labor costs,minimizes dependence on unknown prior information,and improves data processing ef-ficiency.In this study,we propose an intelligent method for suppressing marine seismic multiples using deep learning approaches.The proposed method enables the intelligent suppression of free-surface-related multiples from seismic records.Initially,we construct a multi-category marine seismic multiple dataset through finite difference forward modeling under different boundary conditions.We use various models and data augmentation methods,including sample rotation,noise addition,and random channel omission.Then,we apply depthwise separable convolution to develop our deep learning Mobilenet-Unet model.The Mobilenet-Unet framework sig-nificantly reduces the number of operations required for multiple elimination without sacrificing model performance,ultimately reali-zing the optimal multiple suppression model.The trained Mobilenet-Unet is applied to the test set for verification.Moreover,to deter-mine its generalization ability,it is implemented to seismic records containing multiples generated by two marine geophysical models that were not included in the training process.The performance of Mobilenet-Unet is also compared with that of different network structures.The results indicate that,despite its small size,our proposed Mobilenet-Unet deep learning model can rapidly and effective-ly separate multiples in marine seismic data,possessing reasonable generalization ability.展开更多
The deep convolutional neural network U-net has been introduced into adaptive subtraction, which is a critical step in effectively suppressing seismic multiples. The U-net approach has higher precision than the tradit...The deep convolutional neural network U-net has been introduced into adaptive subtraction, which is a critical step in effectively suppressing seismic multiples. The U-net approach has higher precision than the traditional linear regression approach. However, the existing 2D U-net approach with 2D data windows can not deal with elaborate discrepancies between the actual and simulated multiples along the gather direction. It may lead to erroneous preservation of primaries or generate obvious vestigial multiples, especially in complex media. To further enhance the multiple suppression accuracy, we present an adaptive subtraction approach utilizing 3D U-net architecture, which can adaptively separate primaries and multiples utilizing 3D windows. The utilization of 3D windows allows for enhanced depiction of spatial continuity and anisotropy of seismic events along the gather direction in comparison to 2D windows. The 3D U-net approach with 3D windows can more effectively preserve the continuity of primaries and manage the complex disparities between the actual and simulated multiples. The proposed 3D U-net approach exhibits 1 dB improvement in the signal-to-noise ratio compared to the 2D U-net approach, as observed in the synthesis data section, and exhibits more outstanding performance in the preservation of primaries and removal of residual multiples in both synthesis and reality data sections. Moreover, to expedite network training in our proposed 3D U-net approach we employ the transfer learning (TL) strategy by utilizing the network parameters of 3D U-net estimated in the preceding data segment as the initial network parameters of 3D U-net for the subsequent data segment. In the reality data section, the 3D U-net approach incorporating TL reduces the computational expense by 70% compared to the one without TL.展开更多
This paper studies cooperative robust parallel operation of multiple actuators over an undirected communication graph.The plant is modeled as an uncertain linear system,and the actuators are linear and identical.Based...This paper studies cooperative robust parallel operation of multiple actuators over an undirected communication graph.The plant is modeled as an uncertain linear system,and the actuators are linear and identical.Based on the internal model principle,a distributed dynamic output feedback control law is proposed to achieve both robust output regulation of the closed-loop system and plant input sharing among the actuators.A practical example of five motors cooperatively driving an uncertain shaft under an external load torque is presented to show the effectiveness of the proposed control law.展开更多
To conduct marine surveys,multiple unmanned surface vessels(Multi-USV)with different capabilities perform collaborative mapping in multiple designated areas.This paper proposes a task allocation algorithm based on int...To conduct marine surveys,multiple unmanned surface vessels(Multi-USV)with different capabilities perform collaborative mapping in multiple designated areas.This paper proposes a task allocation algorithm based on integer linear programming(ILP)with flow balance constraints,ensuring the fair and efficient distribution of sub-areas among USVs and maintaining strong connectivity of assigned regions.In the established gridmap,a search-based path planning algorithm is performed on the sub-areas according to the allocation scheme.It uses the greedy algorithm and the A*algorithm to achieve complete coverage of the barrier-free area and obtain an efficient trajectory of each USV.The greedy algorithm enables fast local traversal of unvisited grids,while the A*algorithm ensures navigation to escape from deadlock areas and maintains global path continuity.The comparison of task allocation results proves that the task allocation algorithm based on ILP improves the mapping efficiency and task distribution fairness.The proposed allocation method and result analysis provide a certain reference for the practical application ofMulti-USV to perform survey tasks collaboratively.展开更多
Active inflammation in“inactive”progressive multiple sclerosis:Traditionally,the distinction between relapsing-remitting multiple sclerosis and progressive multiple sclerosis(PMS)has been framed as an inflammatory v...Active inflammation in“inactive”progressive multiple sclerosis:Traditionally,the distinction between relapsing-remitting multiple sclerosis and progressive multiple sclerosis(PMS)has been framed as an inflammatory versus degenerative dichotomy.This was based on a broad misconception regarding essentially all neurodegenerative conditions,depicting the degenerative process as passive and immune-independent occurring as a late byproduct of active inflammation in the central nervous system(CNS),which is(solely)systemically driven.展开更多
Multiple sclerosis(MS)is a chronic disorder of the central nervous system characterized by multifocal lesions where inflammation,demyelination,and neurodegeneration occur(Jakimovski et al.,2024).MS diagnosis primarily...Multiple sclerosis(MS)is a chronic disorder of the central nervous system characterized by multifocal lesions where inflammation,demyelination,and neurodegeneration occur(Jakimovski et al.,2024).MS diagnosis primarily relies on the demonstration of dissemination in time and space of the lesions based on clinical,magnetic resonance imaging(MRI),and cerebrospinal fluid assessments(Jakimovski et al.,2024).展开更多
Loss of immune tolerance to central nervous system(CNS)antigens lies at the heart of multiple sclerosis(MS),the most common chronic autoimmune disease of the CNS.MS affects nearly2 million people wo rldwide and is cha...Loss of immune tolerance to central nervous system(CNS)antigens lies at the heart of multiple sclerosis(MS),the most common chronic autoimmune disease of the CNS.MS affects nearly2 million people wo rldwide and is chara cterized by focal areas of demyelination,inflammation,axonal injury,and neurodegeneration(Bronge et al.,2022;Magliozzi et al.,2023).展开更多
Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framew...Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framework that jointly designs distributed observers and local controllers to ensure robust formation control in the presence of external disturbances and sensor malfunctions.Treating the spacecraft formation as a single interconnected system,each spacecraft constructs a distributed observer that estimates the overall system state by incorporating both its own measurements and the predicted control information shared among the spacecraft.Based on the observer estimates,a local control law is synthesized to maintain the desired formation.Rigorous theoretical analysis and numerical simulations demonstrate that the proposed integrated approach effectively guarantees formation stability and resilience against sensor failures and disturbances.展开更多
Shallot and scallion are among the essential horticultural crops in the Mekong Delta of Vietnam,and their yields and quality are affected by the beet armyworm,Spodoptera exigua.To control this pest,farmers have used a...Shallot and scallion are among the essential horticultural crops in the Mekong Delta of Vietnam,and their yields and quality are affected by the beet armyworm,Spodoptera exigua.To control this pest,farmers have used a large number of insecticides,which has led to resistance due to continuous use and environmental harm,thereby increasing interest in biological methods,including the Spodoptera exigua multiple nucleopolyhedrovirus(SeMNPV).The study aims to assess the efficacy of the liquid and powder formulation of SeMNPV against Spodoptera exigua under the actual agricultural conditions of Soc Trang(Shallot)and Vinh Long provinces(Scallion).The experimental arrangement used four treatments:SeMNPV liquid,SeMNPV powder,Radiant 60SC(a chemical insecticide),and the control.Some of the factors evaluated were larval density,level of leaf damage,yield,and natural enemies attack.The SeMNPV powder had the least damage,only 0.97 per cent(damage of plant),and a yield of 28.59 t/ha,and was almost equally good as the Radiant 60SC,which produced a damage of 2.53 per cent(damage of plant)and a yield of 29.41 t/ha.SeMNPV treatments significantly reduced larval numbers(down to fewer than 10 larvae/m2 by day 40)and enhanced natural enemies,parasitoids,and microsporidia.The untreated one had the highest damage(8.03%),while the yield was lowest at 19.61 t/ha.Therefore,SeMNPV in powder form has the potential to control S.exigua infestations and to encourage biological control,making it a favourable,environmentally friendly addition to synthetic insecticides in the cultivation of shallot and scallion.展开更多
With a perspective of interest in the modeling of dynamic processes, here we investigate various types of basic growth equations, which in their formulation quantify the change of the variables, the state, or the inde...With a perspective of interest in the modeling of dynamic processes, here we investigate various types of basic growth equations, which in their formulation quantify the change of the variables, the state, or the independent one, using balance equations in which the counts(aggregation-reduction) are of the multiplicative type. We enter the context of the “differential” equations typical of non-Newtonian calculations, such as geometric calculus, bi-geometric calculus, or the lesser-known logarithmic calculus, when we take the step to the limit. In these new possibilities of dynamic laws, we highlight the interpretive aspects. A particular case is to review the equivalents of the logistic equation of the standard calculation in the new accounting calculations, where we make graphical and semantic comparisons. Finally, the construction of a geometric type equation is exemplified, with applications inherent to the financial mathematics.展开更多
Head-up displays(HUDs)are emerging as key components of intelligent vehicles,requiring wide-depth,large-area,and high-efficiency dynamic imaging,which remains difficult to realize with traditional refractive optics.Co...Head-up displays(HUDs)are emerging as key components of intelligent vehicles,requiring wide-depth,large-area,and high-efficiency dynamic imaging,which remains difficult to realize with traditional refractive optics.Computer-generated holography(CGH)with diffraction optics offers a promising solution to these technical demands.However,CGH optimization based on the fast Fourier transform(FFT)faces limitations such as zero-padding redundancy,coupled sampling intervals,and incompatible near-and farfield propagation models.Here,we report a holography-based multiplane HUD using a matrix multiplication(MM)-assisted diffraction algorithm that restructures the Fresnel integral into two sequential matrix operations,thus eliminating zero-padding and enabling fully decoupled sampling between object and image planes.Compared with FFT-based angular spectrum methods,the MM approach significantly improves computational speed and memory efficiency for hologram design,which is validated by demonstrating dual-plane holography with a size ratio exceeding 100:1 and unified reconstruction across Fresnel and Fraunhofer regimes within a single computation.A prototype HUD system is demonstrated successfully to exhibit multiple-plane holographic virtual images that can be mixed with real-world objects at three independent planes.The technique might be one of the potential candidates for next-generation intelligent vehicle displays.展开更多
This paper is dedicated to fixed-time passivity and synchronization for multi-weighted spatiotemporal directed networks.First,to achieve fixed-time passivity,a type of decentralized power-law controller is developed,i...This paper is dedicated to fixed-time passivity and synchronization for multi-weighted spatiotemporal directed networks.First,to achieve fixed-time passivity,a type of decentralized power-law controller is developed,in which only one parameter needs to be adjusted in the power-law terms;this greatly decreases the inconvenience of parameter adjustment.Second,several fixed-time passivity criteria with LMI forms are derived by using a Gauss divergence theorem to deal with the spatial diffusion of nodes and by applying the Hölder’s inequality to dispose rigorously the power-law term greater than one in the designed control scheme;this improves the previous theoretical analysis.Additionally,the fixed-time synchronization of spatiotemporal directed networks with multi-weights is addressed as a direct result of fixed-time strict passivity.Finally,a numerical example is presented in order to show the validity of the theoretical analysis.展开更多
Driven by the trend of device miniaturization and high-density integration,the interaction between adjacent electrodes has become a critical factor affecting the interfacial reliability of thermoelectric(TE)structures...Driven by the trend of device miniaturization and high-density integration,the interaction between adjacent electrodes has become a critical factor affecting the interfacial reliability of thermoelectric(TE)structures.This study investigates the influence of adjoining electrode interactions on the interfacial response of a multi-electrode/TE substrate structure,including interfacial stresses and stress intensity factors at the electrode ends.To solve the corresponding boundary-value problem,the Fourier transforms are adopted to derive a governing integro-differential equation for the interfacial shear stress in multi-electrode systems,incorporating the TE effects as generalized forces on the right-hand side.The results show that both the interfacial tension and transverse stress in the electrodes are significantly affected by the presence of adjacent electrodes.The interaction between neighboring electrodes diminishes as their spacing increases or when an adhesive interlayer is introduced.Furthermore,the softer and thinner electrodes,the softer and thicker adhesive interlayer,and the smaller TE loads are found to be beneficial for improving the interfacial performance.These findings may contribute to the accurate measurement in surface sensors and layout design of multi-point health monitoring systems for TE structures.展开更多
BACKGROUND The accurate prediction of lymph node metastasis(LNM)is crucial for managing locally advanced(T3/T4)colorectal cancer(CRC).However,both traditional histopathology and standard slide-level deep learning ofte...BACKGROUND The accurate prediction of lymph node metastasis(LNM)is crucial for managing locally advanced(T3/T4)colorectal cancer(CRC).However,both traditional histopathology and standard slide-level deep learning often fail to capture the sparse and diagnostically critical features of metastatic potential.AIM To develop and validate a case-level multiple-instance learning(MIL)framework mimicking a pathologist's comprehensive review and improve T3/T4 CRC LNM prediction.METHODS The whole-slide images of 130 patients with T3/T4 CRC were retrospectively collected.A case-level MIL framework utilising the CONCH v1.5 and UNI2-h deep learning models was trained on features from all haematoxylin and eosinstained primary tumour slides for each patient.These pathological features were subsequently integrated with clinical data,and model performance was evaluated using the area under the curve(AUC).RESULTS The case-level framework demonstrated superior LNM prediction over slide-level training,with the CONCH v1.5 model achieving a mean AUC(±SD)of 0.899±0.033 vs 0.814±0.083,respectively.Integrating pathology features with clinical data further enhanced performance,yielding a top model with a mean AUC of 0.904±0.047,in sharp contrast to a clinical-only model(mean AUC 0.584±0.084).Crucially,a pathologist’s review confirmed that the model-identified high-attention regions correspond to known high-risk histopathological features.CONCLUSION A case-level MIL framework provides a superior approach for predicting LNM in advanced CRC.This method shows promise for risk stratification and therapy decisions,requiring further validation.展开更多
AIM:To investigate the changes of retinal vascular parameters and retinal layer thickness in patients with multiple sclerosis(MS).METHODS:This single-centered case-control study was performed on a MS group of 42 patie...AIM:To investigate the changes of retinal vascular parameters and retinal layer thickness in patients with multiple sclerosis(MS).METHODS:This single-centered case-control study was performed on a MS group of 42 patients diagnosed with MS and a control group of 43 healthy hospital staff matched in terms of age and sex at Iran University,department of neurology and ophthalmology from March 2020 to March 2021.The ophthalmic parameters of each patient were recorded,and optical coherence tomography was used to evaluate the retinal thickness in the layers.RESULTS:This study enrolled a total of 85 participants,with a mean age of 40.44±11.52 years,including 61 females(72%).The control group consisted of 43 individuals with a mean age of 39.49±11.07 years,while the MS group comprised 42 participants with a mean age of 41.40±12.01 years.The mean disease duration in the MS group was 8.45±6.04 a.The thickness of the ganglion cell layer in the right eye was significantly lower in the MS group compared to the control group(P=0.034).In addition,except for the left nasal sector(P=0.106),the mean peripapillary neurofibrillation in all examined sectors were significantly lower in the MS group than in the control group(P<0.05).The average vessel density in both the deep and superficial capillary plexuses across all regions of both eyes was lower in the MS group than in the control group,with all comparisons for the superficial capillary plexus showing statistical significance(P<0.05 for all except the left nasal sector).CONCLUSION:The thickness of the retina of patients with MS is significantly reduced.Therefore,optical coherence tomography results can be used as a reliable tool to evaluate disease progression and prognosis in MS patients.展开更多
Myelination in the central nervous system(CNS)is a highly intricate process,exclusive to vertebrates,that relies on the coordinated interaction between oligodendrocytes(OLs)and neurons.In addition to their role in for...Myelination in the central nervous system(CNS)is a highly intricate process,exclusive to vertebrates,that relies on the coordinated interaction between oligodendrocytes(OLs)and neurons.In addition to their role in forming myelin,accumulating evidence indicates that OLs provide crucial trophic support to axons,contributing to normal CNS function.Notably,OL injury and loss are observed in a variety of human conditions,including stroke,traumatic injuries of the brain and spinal cord,as well as neurodegenerative disorders such as multiple sclerosis(MS).展开更多
Under the influence of human activities,landscape fragmentation in the Wei River Basin(WRB)has become increasingly severe.Upstream development has intensified soil erosion,and industrial and agricultural pollution in ...Under the influence of human activities,landscape fragmentation in the Wei River Basin(WRB)has become increasingly severe.Upstream development has intensified soil erosion,and industrial and agricultural pollution in the middle reaches has degraded water quality.Rapid urbanization has further caused habitat fragmentation and biodiversity loss.Collectively,these challenges threaten human well-being and hinder sustainable development,making the construction and optimization of an ecological security pattern(ESP)urgently necessary.However,existing studies often fail to systematically integrate future landscape ecological risk(LER)assessment with ESP optimization.This study evaluated regional LER using the“ecological patches-ecological resistance surface(ERS)-ecological corridor”framework,combined with land-use predictions under three development scenarios,and optimized the ESP by adjusting the ERS and extracting ecological corridors.The results indicate that the LER in the WRB follows an“inverted N”distribution,with low-risk areas concentrated in forested mountain regions and high-risk areas mainly in cultivated land subject to intensive human activity.Across future scenarios,ESPs showed fewer ecological breakpoints and improved landscape connectivity than the 2020 baseline.Scenario-based differences emerged in the spatial configuration of ERS adjustments,with the ecological protection scenario yielding the lowest LER and most favorable ESP.This study demonstrates the deep integration of multi-scenario simulation with LER assessment,providing a new framework for ESP optimization.The findings have guiding significance for ecological protection and coordinated development in the WRB and offer a novel paradigm for sustainable development in ecologically fragile basins worldwide.展开更多
To solve the problem of in-flight actuator faults and parameter uncertainties for multiple Unmanned Aerial Vehicles(UAVs),and reduce the communication and computational resource consumption of multiple UAVs,a Fraction...To solve the problem of in-flight actuator faults and parameter uncertainties for multiple Unmanned Aerial Vehicles(UAVs),and reduce the communication and computational resource consumption of multiple UAVs,a Fraction-Order(FO)sliding-mode Fault-Tolerant Cooperative Control(FTCC)strategy is proposed for multiple UAVs based on Event-Triggered Communication Mechanism(ET-COM-M)and Event-Triggered Control Mechanism(ET-CON-M).First,by considering the limited communication bandwidth of multiple UAVs in formation,an ET-COM-M is designed to significantly reduce communication times.Then,a distributed observer is skillfully constructed to estimate the reference signals for follower UAVs.Moreover,the adaptive strategy is incorporated into the Radial Basis Function Neural Network(RBFNN)to learn the lumped unknown terms for handling bias actuator faults and parameter uncertainties.Besides,the Nussbaum method is used to deal with the loss-of-effectiveness faults.To further achieve the refined control performance against faults,FO calculus is artfully integrated into the sliding-mode control protocol with ET-CON-M.Finally,Zeno behavior is excluded by rigorous theoretical analysis and Lyapunov stability is proved to show the effectiveness of the designed FTCC strategy.Simulation results show that the designed FTCC strategy with Event-Triggered Mechanism(ETM)can guarantee the safety of multiple UAVs and simultaneously reduce the communication and control frequencies,making the developed control scheme applicable in engineering.展开更多
This paper presents a hierarchical formation control strategy to address the challenges of multiple Unmanned Aerial Vehicles(UAVs)formation control within a cooperative consensus framework.The proposed strategy incorp...This paper presents a hierarchical formation control strategy to address the challenges of multiple Unmanned Aerial Vehicles(UAVs)formation control within a cooperative consensus framework.The proposed strategy incorporates a reference command generation layer,which derives UAV attitude commands based on formation requirements,and a tracking control layer to ensure accurate execution.Collaborative variables,including trajectory position and flight speed,are defined using a three-dimensional track particle and autopilot model,enabling the development of a consensus-based formation control law.Desired attitude angles are computed through altitudehold and coordinated-turn strategies.A sliding surface is designed based on reference models derived from flight quality metrics,while an adaptive controller compensates for aerodynamic model uncertainties.To enhance learning capabilities,a prediction error mechanism based on a series-parallel estimation model is introduced,enabling collaborative learning and the sharing of network weight estimation parameters within the multi-agent system.This facilitates the design of a distributed composite learning law.Lyapunov stability analysis confirms the local exponential stability of the tracking error.The simulations of a twelve-UAV formation,along with comparative analysis of two algorithms,demonstrate the system’s capability for formation maintenance and high-precision tracking control.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52474339)Anhui Province Outstanding Research and Innovation Team in Higher Education Institutions(Grant No.2022AH010024).
文摘The free-surface vortex is a rotational flow phenomenon characterized by two-phase coupling,formed by the rupture of surface fluid in the final stage of discharge.It is a significant concept with broad applications in engineering fields like metallurgy and hydraulics.The basic concepts and characteristics of free-surface vortices were introduced,and their hazards in various fields were discussed.The development of theoretical and numerical models over recent decades was reviewed,and the factors affecting vortex formation and existing suppression methods were outlined.Finally,the key challenges and focus areas on the study of free-surface vortex were summarized.With the ongoing advancements in computational fluid dynamics and experimental technology,research on free-surface vortices will become more in depth and precise.Additionally,interdisciplinary cooperation and technological innovation are expected to achieve precise control and optimal design of free-surface vortices,offering more efficient and sustainable solutions for metallurgy and related engineering fields.
基金supported by the Key Laboratory of Ma-rine Mineral Resources,Ministry of Natural Resources,Guangzhou(No.KLMMR-2022-G09)the Guangzhou Ba-sic Research Program-Basic and Basic Applied Research Project(No.2023A04J0917)the PI Project of South-ern Marine Science and Engineering Guangdong Labora-tory(Guangzhou)(No.GML2020GD0802).
文摘Multiple suppression is an important element of marine seismic data processing.Intelligent suppression of multiples us-ing artificial intelligence reduces labor costs,minimizes dependence on unknown prior information,and improves data processing ef-ficiency.In this study,we propose an intelligent method for suppressing marine seismic multiples using deep learning approaches.The proposed method enables the intelligent suppression of free-surface-related multiples from seismic records.Initially,we construct a multi-category marine seismic multiple dataset through finite difference forward modeling under different boundary conditions.We use various models and data augmentation methods,including sample rotation,noise addition,and random channel omission.Then,we apply depthwise separable convolution to develop our deep learning Mobilenet-Unet model.The Mobilenet-Unet framework sig-nificantly reduces the number of operations required for multiple elimination without sacrificing model performance,ultimately reali-zing the optimal multiple suppression model.The trained Mobilenet-Unet is applied to the test set for verification.Moreover,to deter-mine its generalization ability,it is implemented to seismic records containing multiples generated by two marine geophysical models that were not included in the training process.The performance of Mobilenet-Unet is also compared with that of different network structures.The results indicate that,despite its small size,our proposed Mobilenet-Unet deep learning model can rapidly and effective-ly separate multiples in marine seismic data,possessing reasonable generalization ability.
基金supported by National Natural Science Foundation of China(42364008,41804110)in part by Guizhou Provincial Basic Research Program(Natural Science)(ZK[2022]060)+1 种基金in part by China Postdoctoral Science Foundation(2022M723127)in part by Youth Innovation Team Project of Shandong Provincial Education Department(2022KJ141).
文摘The deep convolutional neural network U-net has been introduced into adaptive subtraction, which is a critical step in effectively suppressing seismic multiples. The U-net approach has higher precision than the traditional linear regression approach. However, the existing 2D U-net approach with 2D data windows can not deal with elaborate discrepancies between the actual and simulated multiples along the gather direction. It may lead to erroneous preservation of primaries or generate obvious vestigial multiples, especially in complex media. To further enhance the multiple suppression accuracy, we present an adaptive subtraction approach utilizing 3D U-net architecture, which can adaptively separate primaries and multiples utilizing 3D windows. The utilization of 3D windows allows for enhanced depiction of spatial continuity and anisotropy of seismic events along the gather direction in comparison to 2D windows. The 3D U-net approach with 3D windows can more effectively preserve the continuity of primaries and manage the complex disparities between the actual and simulated multiples. The proposed 3D U-net approach exhibits 1 dB improvement in the signal-to-noise ratio compared to the 2D U-net approach, as observed in the synthesis data section, and exhibits more outstanding performance in the preservation of primaries and removal of residual multiples in both synthesis and reality data sections. Moreover, to expedite network training in our proposed 3D U-net approach we employ the transfer learning (TL) strategy by utilizing the network parameters of 3D U-net estimated in the preceding data segment as the initial network parameters of 3D U-net for the subsequent data segment. In the reality data section, the 3D U-net approach incorporating TL reduces the computational expense by 70% compared to the one without TL.
基金Supported by the Shenzhen Key Laboratory of Control Theory and Intelligent Systems (ZDSYS20220330161800001)the National Natural Science Foundation of China (62303207)the Guangdong Basic and Applied Basic Research Foundation (2024A1515010725)。
文摘This paper studies cooperative robust parallel operation of multiple actuators over an undirected communication graph.The plant is modeled as an uncertain linear system,and the actuators are linear and identical.Based on the internal model principle,a distributed dynamic output feedback control law is proposed to achieve both robust output regulation of the closed-loop system and plant input sharing among the actuators.A practical example of five motors cooperatively driving an uncertain shaft under an external load torque is presented to show the effectiveness of the proposed control law.
基金supported in part by the International Science and Technology Project of Guangzhou Development District under Grant 2023GH08the Science and Technology Development Fund,MSAR,under Grants 0029/2022/AGJ and 0029/2023/RIA1the Program of Guangdong under Grant 2023A0505020003.
文摘To conduct marine surveys,multiple unmanned surface vessels(Multi-USV)with different capabilities perform collaborative mapping in multiple designated areas.This paper proposes a task allocation algorithm based on integer linear programming(ILP)with flow balance constraints,ensuring the fair and efficient distribution of sub-areas among USVs and maintaining strong connectivity of assigned regions.In the established gridmap,a search-based path planning algorithm is performed on the sub-areas according to the allocation scheme.It uses the greedy algorithm and the A*algorithm to achieve complete coverage of the barrier-free area and obtain an efficient trajectory of each USV.The greedy algorithm enables fast local traversal of unvisited grids,while the A*algorithm ensures navigation to escape from deadlock areas and maintains global path continuity.The comparison of task allocation results proves that the task allocation algorithm based on ILP improves the mapping efficiency and task distribution fairness.The proposed allocation method and result analysis provide a certain reference for the practical application ofMulti-USV to perform survey tasks collaboratively.
文摘Active inflammation in“inactive”progressive multiple sclerosis:Traditionally,the distinction between relapsing-remitting multiple sclerosis and progressive multiple sclerosis(PMS)has been framed as an inflammatory versus degenerative dichotomy.This was based on a broad misconception regarding essentially all neurodegenerative conditions,depicting the degenerative process as passive and immune-independent occurring as a late byproduct of active inflammation in the central nervous system(CNS),which is(solely)systemically driven.
基金supported by Italian Ministry for Health(RF-2011-02349698,RF-2018-12367731)(to CF).
文摘Multiple sclerosis(MS)is a chronic disorder of the central nervous system characterized by multifocal lesions where inflammation,demyelination,and neurodegeneration occur(Jakimovski et al.,2024).MS diagnosis primarily relies on the demonstration of dissemination in time and space of the lesions based on clinical,magnetic resonance imaging(MRI),and cerebrospinal fluid assessments(Jakimovski et al.,2024).
文摘Loss of immune tolerance to central nervous system(CNS)antigens lies at the heart of multiple sclerosis(MS),the most common chronic autoimmune disease of the CNS.MS affects nearly2 million people wo rldwide and is chara cterized by focal areas of demyelination,inflammation,axonal injury,and neurodegeneration(Bronge et al.,2022;Magliozzi et al.,2023).
基金supported by the National Natural Science Foundation of China(62088101,62522307,62273045,U2341213)Beijing Nova Program(20230484481)。
文摘Formation control of multiple spacecraft has attracted extensive research attention.However,achieving reliable performance under sensor failures remains a significant challenge.This paper develops an integrated framework that jointly designs distributed observers and local controllers to ensure robust formation control in the presence of external disturbances and sensor malfunctions.Treating the spacecraft formation as a single interconnected system,each spacecraft constructs a distributed observer that estimates the overall system state by incorporating both its own measurements and the predicted control information shared among the spacecraft.Based on the observer estimates,a local control law is synthesized to maintain the desired formation.Rigorous theoretical analysis and numerical simulations demonstrate that the proposed integrated approach effectively guarantees formation stability and resilience against sensor failures and disturbances.
文摘Shallot and scallion are among the essential horticultural crops in the Mekong Delta of Vietnam,and their yields and quality are affected by the beet armyworm,Spodoptera exigua.To control this pest,farmers have used a large number of insecticides,which has led to resistance due to continuous use and environmental harm,thereby increasing interest in biological methods,including the Spodoptera exigua multiple nucleopolyhedrovirus(SeMNPV).The study aims to assess the efficacy of the liquid and powder formulation of SeMNPV against Spodoptera exigua under the actual agricultural conditions of Soc Trang(Shallot)and Vinh Long provinces(Scallion).The experimental arrangement used four treatments:SeMNPV liquid,SeMNPV powder,Radiant 60SC(a chemical insecticide),and the control.Some of the factors evaluated were larval density,level of leaf damage,yield,and natural enemies attack.The SeMNPV powder had the least damage,only 0.97 per cent(damage of plant),and a yield of 28.59 t/ha,and was almost equally good as the Radiant 60SC,which produced a damage of 2.53 per cent(damage of plant)and a yield of 29.41 t/ha.SeMNPV treatments significantly reduced larval numbers(down to fewer than 10 larvae/m2 by day 40)and enhanced natural enemies,parasitoids,and microsporidia.The untreated one had the highest damage(8.03%),while the yield was lowest at 19.61 t/ha.Therefore,SeMNPV in powder form has the potential to control S.exigua infestations and to encourage biological control,making it a favourable,environmentally friendly addition to synthetic insecticides in the cultivation of shallot and scallion.
文摘With a perspective of interest in the modeling of dynamic processes, here we investigate various types of basic growth equations, which in their formulation quantify the change of the variables, the state, or the independent one, using balance equations in which the counts(aggregation-reduction) are of the multiplicative type. We enter the context of the “differential” equations typical of non-Newtonian calculations, such as geometric calculus, bi-geometric calculus, or the lesser-known logarithmic calculus, when we take the step to the limit. In these new possibilities of dynamic laws, we highlight the interpretive aspects. A particular case is to review the equivalents of the logistic equation of the standard calculation in the new accounting calculations, where we make graphical and semantic comparisons. Finally, the construction of a geometric type equation is exemplified, with applications inherent to the financial mathematics.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB3607300)the National Natural Science Foundation of China(Grant Nos.62322512,62225506,and 12134013)+7 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.WK2030000108 and WK2030000090)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-049)supported by the National Natural Science Foundation of China(Grant Nos.12174260 and 12574326)the Shanghai Rising-Star Program(Grant No.21QA1406400)the Shanghai Science and Technology Development Fund(Grant Nos.21ZR1443500 and 21ZR1443600)the support from the China Postdoctoral Science Foundation(Grant No.2023M743364)support from the Center for Micro and Nanoscale Research and Fabrication,University of Science and Technology of Chinasupported by the UPOLabs,which provided the experimental and technical support。
文摘Head-up displays(HUDs)are emerging as key components of intelligent vehicles,requiring wide-depth,large-area,and high-efficiency dynamic imaging,which remains difficult to realize with traditional refractive optics.Computer-generated holography(CGH)with diffraction optics offers a promising solution to these technical demands.However,CGH optimization based on the fast Fourier transform(FFT)faces limitations such as zero-padding redundancy,coupled sampling intervals,and incompatible near-and farfield propagation models.Here,we report a holography-based multiplane HUD using a matrix multiplication(MM)-assisted diffraction algorithm that restructures the Fresnel integral into two sequential matrix operations,thus eliminating zero-padding and enabling fully decoupled sampling between object and image planes.Compared with FFT-based angular spectrum methods,the MM approach significantly improves computational speed and memory efficiency for hologram design,which is validated by demonstrating dual-plane holography with a size ratio exceeding 100:1 and unified reconstruction across Fresnel and Fraunhofer regimes within a single computation.A prototype HUD system is demonstrated successfully to exhibit multiple-plane holographic virtual images that can be mixed with real-world objects at three independent planes.The technique might be one of the potential candidates for next-generation intelligent vehicle displays.
基金supported by the National Natural Science Foundation of China(62373317)the Tianshan Talent Training Program(2022TSYCCX0013)+3 种基金the Key Project of Natural Science Foundation of Xinjiang(2021D01D10)the Basic Research Foundation for Universities of Xinjiang(XJEDU2023P023)the Xinjiang Key Laboratory of Applied Mathematics(XJDX1401)the Intelligent Control and Optimization Research Platform in Xinjiang University.
文摘This paper is dedicated to fixed-time passivity and synchronization for multi-weighted spatiotemporal directed networks.First,to achieve fixed-time passivity,a type of decentralized power-law controller is developed,in which only one parameter needs to be adjusted in the power-law terms;this greatly decreases the inconvenience of parameter adjustment.Second,several fixed-time passivity criteria with LMI forms are derived by using a Gauss divergence theorem to deal with the spatial diffusion of nodes and by applying the Hölder’s inequality to dispose rigorously the power-law term greater than one in the designed control scheme;this improves the previous theoretical analysis.Additionally,the fixed-time synchronization of spatiotemporal directed networks with multi-weights is addressed as a direct result of fixed-time strict passivity.Finally,a numerical example is presented in order to show the validity of the theoretical analysis.
基金Project supported by the National Natural Science Foundation of China(Nos.12502117,12272269,11972257)the Natural Science Foundation of Ningxia of China(No.2024AAC03018)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Shanghai Gaofeng Project for University Academic Program Development。
文摘Driven by the trend of device miniaturization and high-density integration,the interaction between adjacent electrodes has become a critical factor affecting the interfacial reliability of thermoelectric(TE)structures.This study investigates the influence of adjoining electrode interactions on the interfacial response of a multi-electrode/TE substrate structure,including interfacial stresses and stress intensity factors at the electrode ends.To solve the corresponding boundary-value problem,the Fourier transforms are adopted to derive a governing integro-differential equation for the interfacial shear stress in multi-electrode systems,incorporating the TE effects as generalized forces on the right-hand side.The results show that both the interfacial tension and transverse stress in the electrodes are significantly affected by the presence of adjacent electrodes.The interaction between neighboring electrodes diminishes as their spacing increases or when an adhesive interlayer is introduced.Furthermore,the softer and thinner electrodes,the softer and thicker adhesive interlayer,and the smaller TE loads are found to be beneficial for improving the interfacial performance.These findings may contribute to the accurate measurement in surface sensors and layout design of multi-point health monitoring systems for TE structures.
基金Supported by Chongqing Medical Scientific Research Project(Joint Project of Chongqing Health Commission and Science and Technology Bureau),No.2023MSXM060.
文摘BACKGROUND The accurate prediction of lymph node metastasis(LNM)is crucial for managing locally advanced(T3/T4)colorectal cancer(CRC).However,both traditional histopathology and standard slide-level deep learning often fail to capture the sparse and diagnostically critical features of metastatic potential.AIM To develop and validate a case-level multiple-instance learning(MIL)framework mimicking a pathologist's comprehensive review and improve T3/T4 CRC LNM prediction.METHODS The whole-slide images of 130 patients with T3/T4 CRC were retrospectively collected.A case-level MIL framework utilising the CONCH v1.5 and UNI2-h deep learning models was trained on features from all haematoxylin and eosinstained primary tumour slides for each patient.These pathological features were subsequently integrated with clinical data,and model performance was evaluated using the area under the curve(AUC).RESULTS The case-level framework demonstrated superior LNM prediction over slide-level training,with the CONCH v1.5 model achieving a mean AUC(±SD)of 0.899±0.033 vs 0.814±0.083,respectively.Integrating pathology features with clinical data further enhanced performance,yielding a top model with a mean AUC of 0.904±0.047,in sharp contrast to a clinical-only model(mean AUC 0.584±0.084).Crucially,a pathologist’s review confirmed that the model-identified high-attention regions correspond to known high-risk histopathological features.CONCLUSION A case-level MIL framework provides a superior approach for predicting LNM in advanced CRC.This method shows promise for risk stratification and therapy decisions,requiring further validation.
文摘AIM:To investigate the changes of retinal vascular parameters and retinal layer thickness in patients with multiple sclerosis(MS).METHODS:This single-centered case-control study was performed on a MS group of 42 patients diagnosed with MS and a control group of 43 healthy hospital staff matched in terms of age and sex at Iran University,department of neurology and ophthalmology from March 2020 to March 2021.The ophthalmic parameters of each patient were recorded,and optical coherence tomography was used to evaluate the retinal thickness in the layers.RESULTS:This study enrolled a total of 85 participants,with a mean age of 40.44±11.52 years,including 61 females(72%).The control group consisted of 43 individuals with a mean age of 39.49±11.07 years,while the MS group comprised 42 participants with a mean age of 41.40±12.01 years.The mean disease duration in the MS group was 8.45±6.04 a.The thickness of the ganglion cell layer in the right eye was significantly lower in the MS group compared to the control group(P=0.034).In addition,except for the left nasal sector(P=0.106),the mean peripapillary neurofibrillation in all examined sectors were significantly lower in the MS group than in the control group(P<0.05).The average vessel density in both the deep and superficial capillary plexuses across all regions of both eyes was lower in the MS group than in the control group,with all comparisons for the superficial capillary plexus showing statistical significance(P<0.05 for all except the left nasal sector).CONCLUSION:The thickness of the retina of patients with MS is significantly reduced.Therefore,optical coherence tomography results can be used as a reliable tool to evaluate disease progression and prognosis in MS patients.
文摘Myelination in the central nervous system(CNS)is a highly intricate process,exclusive to vertebrates,that relies on the coordinated interaction between oligodendrocytes(OLs)and neurons.In addition to their role in forming myelin,accumulating evidence indicates that OLs provide crucial trophic support to axons,contributing to normal CNS function.Notably,OL injury and loss are observed in a variety of human conditions,including stroke,traumatic injuries of the brain and spinal cord,as well as neurodegenerative disorders such as multiple sclerosis(MS).
基金supported by the National Natural Science Foundation of China[Grant No.42361040].
文摘Under the influence of human activities,landscape fragmentation in the Wei River Basin(WRB)has become increasingly severe.Upstream development has intensified soil erosion,and industrial and agricultural pollution in the middle reaches has degraded water quality.Rapid urbanization has further caused habitat fragmentation and biodiversity loss.Collectively,these challenges threaten human well-being and hinder sustainable development,making the construction and optimization of an ecological security pattern(ESP)urgently necessary.However,existing studies often fail to systematically integrate future landscape ecological risk(LER)assessment with ESP optimization.This study evaluated regional LER using the“ecological patches-ecological resistance surface(ERS)-ecological corridor”framework,combined with land-use predictions under three development scenarios,and optimized the ESP by adjusting the ERS and extracting ecological corridors.The results indicate that the LER in the WRB follows an“inverted N”distribution,with low-risk areas concentrated in forested mountain regions and high-risk areas mainly in cultivated land subject to intensive human activity.Across future scenarios,ESPs showed fewer ecological breakpoints and improved landscape connectivity than the 2020 baseline.Scenario-based differences emerged in the spatial configuration of ERS adjustments,with the ecological protection scenario yielding the lowest LER and most favorable ESP.This study demonstrates the deep integration of multi-scenario simulation with LER assessment,providing a new framework for ESP optimization.The findings have guiding significance for ecological protection and coordinated development in the WRB and offer a novel paradigm for sustainable development in ecologically fragile basins worldwide.
基金supported in part by National Natural Science Foundation of China(Nos.62373188,62003162)the Natural Science Foundation of Jiangsu Province of China(Nos.BK20240182,BK20222012)+2 种基金the Industry-University Research Innovation Foundation for the Chinese Ministry of Education(No.2021ZYA02005)the Aeronautical Science Foundation of China(Nos.20220007052003,20200007018001)the Fundamental Research Funds for the Central Universities,China(Nos.NE2024004,NI2024001)。
文摘To solve the problem of in-flight actuator faults and parameter uncertainties for multiple Unmanned Aerial Vehicles(UAVs),and reduce the communication and computational resource consumption of multiple UAVs,a Fraction-Order(FO)sliding-mode Fault-Tolerant Cooperative Control(FTCC)strategy is proposed for multiple UAVs based on Event-Triggered Communication Mechanism(ET-COM-M)and Event-Triggered Control Mechanism(ET-CON-M).First,by considering the limited communication bandwidth of multiple UAVs in formation,an ET-COM-M is designed to significantly reduce communication times.Then,a distributed observer is skillfully constructed to estimate the reference signals for follower UAVs.Moreover,the adaptive strategy is incorporated into the Radial Basis Function Neural Network(RBFNN)to learn the lumped unknown terms for handling bias actuator faults and parameter uncertainties.Besides,the Nussbaum method is used to deal with the loss-of-effectiveness faults.To further achieve the refined control performance against faults,FO calculus is artfully integrated into the sliding-mode control protocol with ET-CON-M.Finally,Zeno behavior is excluded by rigorous theoretical analysis and Lyapunov stability is proved to show the effectiveness of the designed FTCC strategy.Simulation results show that the designed FTCC strategy with Event-Triggered Mechanism(ETM)can guarantee the safety of multiple UAVs and simultaneously reduce the communication and control frequencies,making the developed control scheme applicable in engineering.
基金co-supported in part by the National Natural Science Foundation of China(No.62403131)in part by Jiangsu Funding Program for Excellent Postdoctoral Talent,China(No.2024ZB267)in part by the Shenzhen Science and Technology Program,China(No.JCYJ20230807145500002)。
文摘This paper presents a hierarchical formation control strategy to address the challenges of multiple Unmanned Aerial Vehicles(UAVs)formation control within a cooperative consensus framework.The proposed strategy incorporates a reference command generation layer,which derives UAV attitude commands based on formation requirements,and a tracking control layer to ensure accurate execution.Collaborative variables,including trajectory position and flight speed,are defined using a three-dimensional track particle and autopilot model,enabling the development of a consensus-based formation control law.Desired attitude angles are computed through altitudehold and coordinated-turn strategies.A sliding surface is designed based on reference models derived from flight quality metrics,while an adaptive controller compensates for aerodynamic model uncertainties.To enhance learning capabilities,a prediction error mechanism based on a series-parallel estimation model is introduced,enabling collaborative learning and the sharing of network weight estimation parameters within the multi-agent system.This facilitates the design of a distributed composite learning law.Lyapunov stability analysis confirms the local exponential stability of the tracking error.The simulations of a twelve-UAV formation,along with comparative analysis of two algorithms,demonstrate the system’s capability for formation maintenance and high-precision tracking control.
