As an important mechanism in multi-agent interaction,communication can make agents form complex team relationships rather than constitute a simple set of multiple independent agents.However,the existing communication ...As an important mechanism in multi-agent interaction,communication can make agents form complex team relationships rather than constitute a simple set of multiple independent agents.However,the existing communication schemes can bring much timing redundancy and irrelevant messages,which seriously affects their practical application.To solve this problem,this paper proposes a targeted multiagent communication algorithm based on state control(SCTC).The SCTC uses a gating mechanism based on state control to reduce the timing redundancy of communication between agents and determines the interaction relationship between agents and the importance weight of a communication message through a series connection of hard-and self-attention mechanisms,realizing targeted communication message processing.In addition,by minimizing the difference between the fusion message generated from a real communication message of each agent and a fusion message generated from the buffered message,the correctness of the final action choice of the agent is ensured.Our evaluation using a challenging set of Star Craft II benchmarks indicates that the SCTC can significantly improve the learning performance and reduce the communication overhead between agents,thus ensuring better cooperation between agents.展开更多
Farmers’subjectivity spirit is the fundamental political and ethical spirit of targeted poverty alleviation.A standardized analysis based on the whole process of targeted poverty alleviation easily reveals that the s...Farmers’subjectivity spirit is the fundamental political and ethical spirit of targeted poverty alleviation.A standardized analysis based on the whole process of targeted poverty alleviation easily reveals that the subjectivity spirit of farmers can be summarized into the spirit of extensive equality of participation,the spirit of complete standardization of procedures,and the spirit of seeking benefits for people as a result.However,the current work on targeted poverty alleviation has confronted with various hidden worries about the farmers’subjectivity dilemma,which leads to the alienation of poverty alleviation work.The key way only to solve the problem is to cultivate the farmers’subjectivity culture and integrate it into the whole process of targeted poverty alleviation.展开更多
Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some ...Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some pathologic conditions.However,the law of展开更多
Bone tumour is one of most common primary cancer which exhibits cancerous osteoblastic differentiation and malignant osteoid in patients.At present,chemotherapy(pre-and post-operative)is used as a standard treatment p...Bone tumour is one of most common primary cancer which exhibits cancerous osteoblastic differentiation and malignant osteoid in patients.At present,chemotherapy(pre-and post-operative)is used as a standard treatment protocol for bone tumour.However,drugs used in the treatment of bone tumour induce high toxicity to normal tissues including anaemia,neutropenia,thrombocytopenia,and heart damage which further reduce the survival rate of patients.Therefore,there is an urgent need to develop a new therapeutic approach for the treatment such that it induce maximum cell killing effect in tumor cells while sparing the healthy bone cells.In this article,some new perspectives were provided on the development of bone-targeted nano-drug carriers for bone cancer treatment.We hope such discussions wouldencourage more detailed and careful studies to support product development of bone-targeted drug carriers for bone cancer treatment.展开更多
Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugate...Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugated nanoparticles and load mitoxantrone nanoparticles(FA-CSNP/MTX). Drug dissolution testing, CCK-8 method, and confocal microscopy were used to detect their controlled-release capability in different situations and the specific uptake by HONE1 cells. The experimental results show that the nanoparticles have uniform size distribution of 48-58 nm. The highest encapsulation rate of the particles on mitoxantrone hydrochloride(MTX) is(77.5±1.9)%, and the drug loading efficiency is(18.4±0.4)%. The sustained release effect, cell growth inhibition activity and targeting effect of the FA-CS/MTX nanoparticles are good in artificial gastric fluid and intestinal fluid. It is demonstrated that the FA-CSNP system is a potentially useful system for the targeted delivery of anticancer drug MTX.展开更多
Thrombospondin 4(THBS4;TSP4),a crucial component of the extracellular matrix(ECM),serves as an important regulator of tissue homeostasis and various pathophysiological processes.As a member of the evolutionarily conse...Thrombospondin 4(THBS4;TSP4),a crucial component of the extracellular matrix(ECM),serves as an important regulator of tissue homeostasis and various pathophysiological processes.As a member of the evolutionarily conserved thrombospondin family,THBS4 is a multidomain adhesive glycoprotein characterized by six distinct structural domains that mediate its diverse biological functions.Through dynamic interactions with various ECM components,THBS4 plays pivotal roles in cell adhesion,proliferation,inflammation regulation,and tissue remodeling,establishing it as a key modulator of microenvironmental organization.The transcription and translation of THBS4 gene,as well as the activity of the THBS4 protein,are tightly regulated by multiple signaling pathways and extracellular cues.Positive regulators of THBS4 include transforming growth factorβ(TGF-β),interferonγ(IFNγ),granulocyte-macrophage colony-stimulating factor(GM-CSF),bone morphogenetic proteins(BMP12/13),and other regulatory factors(such as B4GALNT1,ITGA2/ITGB1,PDGFRβ,etc.),which upregulate THBS4 at the mRNA and/or protein level.Conversely,oxidized low-density lipoprotein(OXLDL)acts as a potent negative regulator of THBS4.This intricate regulatory network ensures precise spatial and temporal control of THBS4 expression in response to diverse physiological and pathological stimuli.Functionally,THBS4 acts as a critical signaling hub,influencing multiple downstream pathways essential for cellular behavior and tissue homeostasis.The best-characterized pathways include:(1)the PI3K/AKT/mTOR axis,which THBS4 modulates through both direct and indirect interactions with integrins and growth factor receptors;(2)Wnt/β-catenin signaling,where THBS4 functions as either an activator or inhibitor depending on the cellular context;(3)the suppression of DBET/TRIM69,contributing to its diverse regulatory roles.These signaling connections position THBS4 as a master regulator of cellular responses to microenvironmental changes.Substantial evidence links aberrant THBS4 expression to a range of pathological conditions,including neoplastic diseases,cardiovascular disorders,fibrotic conditions,neurodegenerative diseases,musculoskeletal disorders,and atopic dermatitis.In cancer biology,THBS4 exhibits context-dependent roles,functioning either as a tumor suppressor or promoter depending on the tumor type and microenvironment.In the cardiovascular system,THBS4 contributes to both adaptive remodeling and maladaptive fibrotic responses.Its involvement in fibrotic diseases arises from its ability to regulate ECM deposition and turnover.The diagnostic and therapeutic potential of THBS4 is particularly promising in oncology and cardiovascular medicine.As a biomarker,THBS4 expression patterns correlate significantly with disease progression and patient outcomes.Therapeutically,targeting THBS4-mediated pathways offers novel opportunities for precision medicine approaches,including anti-fibrotic therapies,modulation of the tumor microenvironment,and enhancement of tissue repair.This comprehensive review systematically explores three key aspects of THBS4 research:(1)the fundamental biological functions of THBS4 in ECM organization;(2)its mechanistic involvement in various disease pathologies;(3)its emerging potential as both a diagnostic biomarker and therapeutic target.By integrating recent insights from molecular studies,animal models,and clinical investigations,this review provides a framework for understanding the multifaceted roles of THBS4 in health and disease.The synthesis of current knowledge highlights critical research gaps and future directions for exploring THBS4-targeted interventions across multiple disease contexts.Given its unique position at the intersection of ECM biology and cellular signaling,THBS4 represents a promising frontier for the development of novel diagnostic tools and therapeutic strategies in precision medicine.展开更多
The YOLOv8 model faces challenges with dense target distribution and small size,resulting in lower accuracy in dense small target detection.To address these issues,an improved small target detection algorithm based on...The YOLOv8 model faces challenges with dense target distribution and small size,resulting in lower accuracy in dense small target detection.To address these issues,an improved small target detection algorithm based on the YOLOv8 model was proposed in this paper.Firstly,the Global Attention Module(GAM)was introduced to enhance data prediction capability and model expression ability.Secondly,the Space-to-Depth(SPD)module was incorporated into the backbone network for fine-grained feature information learning to mitigate feature information loss due to down-sampling.Finally,a 160 pixels×160 pixels feature layer was added to expand small target feature information and effectively reduce instances of missed targets.Experimental validation on the public VisDrone2019 UAV small target detaset demonstrated that the proposed model achieves significant performance improvement in small target detection tasks compared to existing models,exhibiting higher accuracy.展开更多
Oral squamous cell carcinoma(OSCC)is the most common head and neck malignancy worldwide,accounting for more than 90%of all oral cancers,and is characterized by high invasiveness and poor long-term prognosis.Its etiolo...Oral squamous cell carcinoma(OSCC)is the most common head and neck malignancy worldwide,accounting for more than 90%of all oral cancers,and is characterized by high invasiveness and poor long-term prognosis.Its etiology is multifactorial,involving tobacco use,alcohol consumption,and human papillomavirus(HPV)infection.Oral leukoplakia and erythroplakia are the main precancerous lesions lesions,with oral leukoplakia being the most common.Both OSCC and premalignant lesions are closely associated with aberrant activation of multiple signaling pathways.Post-translational modifications(such as ubiquitination and deubiquitination)play key roles in regulating these pathways by controlling protein stability and activity.Growing evidence indicates that dysregulated ubiquitination/deubiquitination can mediate OSCC initiation and progression via aberrant activation of signaling pathways.The ubiquitination/deubiquitination process mainly involves E3 ligases(E3s)that catalyze substrate ubiquitination,deubiquitinating enzymes(DUBs)that remove ubiquitin chains,and the 26S proteasome complex that degrades ubiquitinated substrates.Abnormal expression or mutation of E3s and DUBs can lead to altered stability of critical tumorrelated proteins,thereby driving OSCC initiation and progression.Therefore,understanding the aberrantly activated signaling pathways in OSCC and the ubiquitination/deubiquitination mechanisms within these pathways will help elucidate the molecular mechanisms and improve OSCC treatment by targeting relevant components.Here,we summarize four aberrantly activated signaling pathways in OSCC―the PI3K/AKT/mTOR pathway,Wnt/β-catenin pathway,Hippo pathway,and canonical NF-κB pathway―and systematically review the regulatory mechanisms of ubiquitination/deubiquitination within these pathways,along with potential drug targets.PI3K/AKT/mTOR pathway is aberrantly activated in approximately 70%of OSCC cases.It is modulated by E3s(e.g.,FBXW7 and NEDD4)and DUBs(e.g.,USP7 and USP10):FBXW7 and USP10 inhibit signaling,while NEDD4 and USP7 potentiate it.Aberrant activation of the Wnt/β-catenin pathway leads toβ-catenin nuclear translocation and induction of cell proliferation.This pathway is modulated by E3s(e.g.,c-Cbl and RNF43)and DUBs(e.g.,USP9X and USP20):c-Cbl and RNF43 inhibit signaling,while USP9X and USP20 potentiate it.Hippo pathway inactivation permits YAP/TAZ to enter the nucleus and promotes cancer cell metastasis.This pathway is modulated by E3s(e.g.,CRL4^(DCAF1) and SIAH2)and DUBs(e.g.,USP1 and USP21):CRL4^(DCAF1) and SIAH2 inhibit signaling,while USP1 and USP21 potentiate it.Persistent activation of the canonical NF-κB pathway is associated with an inflammatory microenvironment and chemotherapy resistance.This pathway is modulated by E3s(e.g.,TRAF6 and LUBAC)and DUBs(e.g.,A20 and CYLD):A20 and CYLD inhibit signaling,while TRAF6 and LUBAC potentiate it.Targeting these E3s and DUBs provides directions for OSCC drug research.Small-molecule inhibitors such as YCH2823(a USP7 inhibitor),GSK2643943A(a USP20 inhibitor),and HOIPIN-8(a LUBAC inhibitor)have shown promising antitumor activity in preclinical models;PROTAC molecules,by binding to surface sites of target proteins and recruiting E3s,achieve targeted ubiquitination and degradation of proteins insensitive to small-molecule inhibitors,for example,PU7-1-mediated USP7 degradation,offering new strategies to overcome traditional drug limitations.Currently,NX-1607(a Cbl-b inhibitor)has entered phase I clinical trials,with preliminary results confirming its safety and antitumor activity.Future research on aberrant E3s and DUBs in OSCC and the development of highly specific inhibitors will be of great significance for OSCC precision therapy.展开更多
In recent years,with the development of synthetic aperture radar(SAR)technology and the widespread application of deep learning,lightweight detection of SAR images has emerged as a research direction.The ultimate goal...In recent years,with the development of synthetic aperture radar(SAR)technology and the widespread application of deep learning,lightweight detection of SAR images has emerged as a research direction.The ultimate goal is to reduce computational and storage requirements while ensuring detection accuracy and reliability,making it an ideal choice for achieving rapid response and efficient processing.In this regard,a lightweight SAR ship target detection algorithm based on YOLOv8 was proposed in this study.Firstly,the C2f-Sc module was designed by fusing the C2f in the backbone network with the ScConv to reduce spatial redundancy and channel redundancy between features in convolutional neural networks.At the same time,the Ghost module was introduced into the neck network to effectively reduce model parameters and computational complexity.A relatively lightweight EMA attention mechanism was added to the neck network to promote the effective fusion of features at different levels.Experimental results showed that the Parameters and GFLOPs of the improved model are reduced by 8.5%and 7.0%when mAP@0.5 and mAP@0.5:0.95 are increased by 0.7%and 1.8%,respectively.It makes the model lightweight and improves the detection accuracy,which has certain application value.展开更多
Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small targe...Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small target detection method based on the tensor nuclear norm and direction residual weighting was proposed.Based on converting the infrared image into an infrared patch tensor model,from the perspective of the low-rank nature of the background tensor,and taking advantage of the difference in contrast between the background and the target in different directions,we designed a double-neighborhood local contrast based on direction residual weighting method(DNLCDRW)combined with the partial sum of tensor nuclear norm(PSTNN)to achieve effective background suppression and recovery of infrared small targets.Experiments show that the algorithm is effective in suppressing the background and improving the detection ability of the target.展开更多
Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ab...Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ability,the arginine-glycine-aspartic(RGD)peptide and the epidermal growth factor receptor interference(EGFRi)peptide were fused with MAP30,which was named ELRL-MAP30.The efficiency of targeted therapy for triple-negative breast cancer(TNBC)MDA-MB-231 cells,which lack the expression of estrogen receptor(ER),Progesterone receptor(PgR)and human epidermal growth factor receptor-2(HER2),is limited.In this study,we focus on exploring the effect and mechanism of ELRL-MAP30 on TNBC MDA-MB-231 cells.First,we discovered that ELRL-MAP30 significantly inhibited the migration and invasion of MDA-MB-231 cells and induced MDA-MB-231 cell apoptosis.Moreover,ELRL-MAP30 treatment resulted in a significant increase in Bax expression and a decrease in Bcl-2 expression.Furthermore,ELRL-MAP30 triggered apoptosis via the Fak/EGFR/Erk and Ilk/Akt signaling pathways.In addition,recombinant ELRL-MAP30 can inhibit chicken embryonic angiogenesis,and also inhibit the tube formation ability of human umbilical vein endothelial cells(HUVECs),indicating its potential therapeutic effects on tumor angiogenesis.Collectively,these results indicate that ELRL-MAP30 has significant tumor-targeting properties in MDA-MB-231 cancer cells and reveals potential therapeutic effects on angiogenesis.These findings indicate the potential role of ELRL-MAP30 in the targeted treatment of the TNBC cell line MDA-MB-231.展开更多
A measurement system for the scattering characteristics of warhead fragments based on high-speed imaging systems offers advantages such as simple deployment,flexible maneuverability,and high spatiotemporal resolution,...A measurement system for the scattering characteristics of warhead fragments based on high-speed imaging systems offers advantages such as simple deployment,flexible maneuverability,and high spatiotemporal resolution,enabling the acquisition of full-process data of the fragment scattering process.However,mismatches between camera frame rates and target velocities can lead to long motion blur tails of high-speed fragment targets,resulting in low signal-to-noise ratios and rendering conventional detection algorithms ineffective in dynamic strong interference testing environments.In this study,we propose a detection framework centered on dynamic strong interference disturbance signal separation and suppression.We introduce a mixture Gaussian model constrained under a joint spatialtemporal-transform domain Dirichlet process,combined with total variation regularization to achieve disturbance signal suppression.Experimental results demonstrate that the proposed disturbance suppression method can be integrated with certain conventional motion target detection tasks,enabling adaptation to real-world data to a certain extent.Moreover,we provide a specific implementation of this process,which achieves a detection rate close to 100%with an approximate 0%false alarm rate in multiple sets of real target field test data.This research effectively advances the development of the field of damage parameter testing.展开更多
An experimental and finite element simulation investigation are conducted to study the deformation patterns of steel targets during the penetration process of tungsten alloy long rods,as well as the influence of stren...An experimental and finite element simulation investigation are conducted to study the deformation patterns of steel targets during the penetration process of tungsten alloy long rods,as well as the influence of strength of the target on the deformation patterns.The experimental results revealed slight mass loss in the first layer of the steel target during the transient entrance phase,with an extremely negligible loss in target mass during the quasi-steady penetration phase.The results of macro-analysis,micro-analysis and simulation show that the eroded target material migrated towards the periphery of the crater,causing an increase in the target's thickness,remained within the target,instead of flowing out of the crater.Therefore,the process of long rods penetrating the metal target is considered as a process of backward extrusion.By combining the backward extrusion theory with energy conservation,a penetration depth model for long rods penetrating a metal target,taking into account both the diameter of the crater and the friction coefficient between the rod and the target,has been established.Although the model is not yet perfect,it innovatively applies the principles of solid mechanics to the study of long rod penetration.Additionally,it takes into account the friction coefficient between the rod and the target during the penetration process.Therefore,this model provides a new research direction for future studies on long rod penetration.展开更多
Multiple quadrotors target encirclement is widely used in the intelligent field,as it can effectively monitor and control target behavior.However,it faces the danger of collision,as well as difficulties in localizatio...Multiple quadrotors target encirclement is widely used in the intelligent field,as it can effectively monitor and control target behavior.However,it faces the danger of collision,as well as difficulties in localization and tracking.Therefore,we propose a complete target encirclement method.Firstly,based on Hooke's law,a collision avoidance controller is designed to maintain a safe flying distance among quadrotors.Then,based on the consensus theory,a formation tracking controller is designed to meet the requirements of formation transformation and encirclement tasks,and a stability proof based on Lyapunov was provided.Besides,the target detection is designed based on YOLOv5s,and the target location model is constructed based on the principle of pinhole projection and triangle similarity.Finally,we conducted experiments on the built platform,with 3 reconnaissance quadrotors detecting and localization 3 target vehicles and 7 hunter quadrotors tracking them.The results show that the minimum average error for localization targets with reconnaissance quadrotors can reach 0.1354 m,while the minimum average error for tracking with hunter quadrotors is only 0.2960 m.No quadrotors collision occurred in the whole formation transformation and tracking experiment.In addition,compared with the advanced methods,the proposed method has better performance.展开更多
Accurate target angle estimation is one of the chal-lenges for wideband radars due to the fact that target occupies multiple range bins,resulting in lower energy or signal to noise ratio in a single range bin.This pap...Accurate target angle estimation is one of the chal-lenges for wideband radars due to the fact that target occupies multiple range bins,resulting in lower energy or signal to noise ratio in a single range bin.This paper proposes a processing technique for enhanced accuracy of target angle estimates for wideband monopulse radars.Firstly,to accumulate the energy of the received echo signals from different scatterers on a target,the phase difference between different scatterers on a target is estimated using the minimum entropy phase estimation method combining with the correlation between adjacent pulses.Then,the monopulse ratio is obtained by using the signals from the accumulated sum and difference channels.The target angle is estimated by weighting the accumulated echo energy for accu-racy enhancement.Experimental results based on both numeri-cal simulation and measured data are presented to validate the effectiveness of the proposed technique.展开更多
A situation maintenance-based cooperative guidance strategy is proposed to intercept a high-speed and high-maneuverability target via inferior missiles.Reachability and relative motion analyses are conducted to develo...A situation maintenance-based cooperative guidance strategy is proposed to intercept a high-speed and high-maneuverability target via inferior missiles.Reachability and relative motion analyses are conducted to develop and pursue virtual targets,respectively.A two-stage guidance strategy under nonlinear kinematics is developed on the basis of virtual targets.The first stage optimizes the coverage and collision situation by pursuing virtual targets under specific angular constraints.The second stage subsequently intercepts the superior target based on the handover condition optimized by the first stage.Numerical simulation results are provided to compare the effectiveness and superiority of the proposed strategy with those of the reachability-based cooperative strategy(RCS),coverage-based cooperative guidance(CBCG)and augmented proportional navigation(APN)under various maneuvering modes.展开更多
With the application of hypervelocity weapons in warfare,comprehensively evaluating their destructive effects is of particular interest for protective engineering.Existing studies mostly focused on the depth of penetr...With the application of hypervelocity weapons in warfare,comprehensively evaluating their destructive effects is of particular interest for protective engineering.Existing studies mostly focused on the depth of penetration by hypervelocity projectile,while investigation on stress waves associated with hypervelocity penetration was very limited.To clarify the generation and propagation of stress waves in concrete targets induced by hypervelocity projectile penetration,in the present study,six spherical projectile penetration tests on concrete targets were firstly conducted with projectile velocity ranged from 1875 m/s to 3940 m/s,in which the stress waves were carefully measured by the PVDF transducers.Then corresponding numerical models were developed and validated,and based on the validated numerical model the mechanisms of generation and propagation of stress waves were clarified.It was found that the stress waves observed during hypervelocity penetration are generated by the continuous interactions of projectile and target during penetration,and have unique characteristics such as the directionality and the"two peaks"phenomenon when compared with the stress waves generated by charge explosion.Finally,the effects of projectile velocity,projectile material,and target strength on the stress waves below the penetration depth we re numerically investigated,and two important indexes for evaluating the stress waves by hypervelocity penetration were proposed.展开更多
The acquisition,tracking,and pointing(ATP)system is widely used in target tracking,counter-UAV operations,and other related fields.As UAV technology develops,there is a growing demand to enhance the tracking capabilit...The acquisition,tracking,and pointing(ATP)system is widely used in target tracking,counter-UAV operations,and other related fields.As UAV technology develops,there is a growing demand to enhance the tracking capabilities of ATP systems.However,in practical applications,ATP systems face various design constraints and functional limitations,making it infeasible to indefinitely improve hardware performance to meet tracking requirements.As a result,tracking algorithms are required to execute increasingly complex tasks.This study introduces a multi-rate feedforward predictive controller to address issues such as low image feedback frequency and significant delays in ATP systems,which lead to tracking jitter,poor tracking performance,low precision,and target loss.At the same time,the pro-posed approach aims to improve the tracking capabilities of ATP systems for high-speed and highly maneuverable targets under conditions of low sampling feedback rates and high feedback delays.The method suggested is also characterized by its low order,fast response,and robustness to model parameter variations.In this study,an actual ATP system is built for target tracking test,and the proposed algorithm is fully validated in terms of simulation and actual system application verification.Results from both simulations and experiments demonstrate that the method effectively compensates for delays and low sampling rates.For targets with relative angular velocities ranging from 0 to 90°/s and angular accelerations between 0 and 470°/s^(2),the system improved tracking accuracy by 70.0%-89.9%at a sampling frequency of 50 Hz and a delay of 30 m s.Moreover,the compensation algorithm demonstrated consistent performance across actuators with varying characteristics,further confirming its robustness to model insensitivity.In summary,the proposed algorithm considerably enhances the tracking accuracy and capability of ATP systems for high-speed and highly maneuverable targets,reducing the probability of target loss from high speed.This approach offers a practical solution for future multi-target tracking across diverse operational scenarios.展开更多
This paper proposes a distributed event-triggered control(ETC)framework to address cooperative target fencing challenges in UAV swarm.The proposed architecture eliminates the reliance on preset formation parameters wh...This paper proposes a distributed event-triggered control(ETC)framework to address cooperative target fencing challenges in UAV swarm.The proposed architecture eliminates the reliance on preset formation parameters while achieving multi-objective cooperative control for target fencing,network connectivity preservation,collision avoidance,and communication efficiency optimization.Firstly,a differential state observer is constructed to obtain the target's unmeasurable states.Secondly,leveraging swarm selforganization principles,a geometric-constraint-free distributed fencing controller is designed by integrating potential field methods with consensus theory.The controller dynamically adjusts inter-UAV distances via single potential function,enabling coordinated optimization of persistent network connectivity and collision-free motion during target fencing.Thirdly,a dual-threshold ETC mechanism based on velocity consensus deviation and fencing error is proposed,which can be triggered based on task features to dynamically adjust the communication frequency,significantly reduce the communication burden and exclude Zeno behavior.Theoretical analysis demonstrates the stability of closed-loop systems.Multi-scenario simulations show that the proposed method can achieve robust fencing under target maneuverability,partial UAV failures,and communication disturbances.展开更多
Unmanned aerial vehicles(UAVs)have become crucial tools in moving target tracking due to their agility and ability to operate in complex,dynamic environments.UAVs must meet several requirements to achieve stable track...Unmanned aerial vehicles(UAVs)have become crucial tools in moving target tracking due to their agility and ability to operate in complex,dynamic environments.UAVs must meet several requirements to achieve stable tracking,including maintaining continuous target visibility amidst occlusions,ensuring flight safety,and achieving smooth trajectory planning.This paper reviews the latest advancements in UAV-based target tracking,highlighting information prediction,tracking strategies,and swarm cooperation.To address challenges including target visibility and occlusion,real-time prediction and tracking in dynamic environments,flight safety and coordination,resource management and energy efficiency,the paper identifies future research directions aimed at improving the performance,reliability,and scalability of UAV tracking system.展开更多
文摘As an important mechanism in multi-agent interaction,communication can make agents form complex team relationships rather than constitute a simple set of multiple independent agents.However,the existing communication schemes can bring much timing redundancy and irrelevant messages,which seriously affects their practical application.To solve this problem,this paper proposes a targeted multiagent communication algorithm based on state control(SCTC).The SCTC uses a gating mechanism based on state control to reduce the timing redundancy of communication between agents and determines the interaction relationship between agents and the importance weight of a communication message through a series connection of hard-and self-attention mechanisms,realizing targeted communication message processing.In addition,by minimizing the difference between the fusion message generated from a real communication message of each agent and a fusion message generated from the buffered message,the correctness of the final action choice of the agent is ensured.Our evaluation using a challenging set of Star Craft II benchmarks indicates that the SCTC can significantly improve the learning performance and reduce the communication overhead between agents,thus ensuring better cooperation between agents.
基金The Project of the Ministry of Education on Humanities and Social Science Study about the Political Ethics of the Establishment of A Community with a Shared Future for Mankind(19YJC710032)
文摘Farmers’subjectivity spirit is the fundamental political and ethical spirit of targeted poverty alleviation.A standardized analysis based on the whole process of targeted poverty alleviation easily reveals that the subjectivity spirit of farmers can be summarized into the spirit of extensive equality of participation,the spirit of complete standardization of procedures,and the spirit of seeking benefits for people as a result.However,the current work on targeted poverty alleviation has confronted with various hidden worries about the farmers’subjectivity dilemma,which leads to the alienation of poverty alleviation work.The key way only to solve the problem is to cultivate the farmers’subjectivity culture and integrate it into the whole process of targeted poverty alleviation.
基金supported by National Natural Science Foundation of China,No.30700151
文摘Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some pathologic conditions.However,the law of
基金The project supported by National Natural Science Foundation of China(81300964)the China Postdoctoral Science Foundation(2013M531611,2014T70648)
文摘Bone tumour is one of most common primary cancer which exhibits cancerous osteoblastic differentiation and malignant osteoid in patients.At present,chemotherapy(pre-and post-operative)is used as a standard treatment protocol for bone tumour.However,drugs used in the treatment of bone tumour induce high toxicity to normal tissues including anaemia,neutropenia,thrombocytopenia,and heart damage which further reduce the survival rate of patients.Therefore,there is an urgent need to develop a new therapeutic approach for the treatment such that it induce maximum cell killing effect in tumor cells while sparing the healthy bone cells.In this article,some new perspectives were provided on the development of bone-targeted nano-drug carriers for bone cancer treatment.We hope such discussions wouldencourage more detailed and careful studies to support product development of bone-targeted drug carriers for bone cancer treatment.
基金Projects(31201074,81371013) supported by the National Natural Science Foundation of ChinaProject(2011105102016) supported by the Key Program of Medical Health of Dongguan City,Guangdong Province,ChinaProject(2011108102026) supported by Dongguan Universities Program,China
文摘Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugated nanoparticles and load mitoxantrone nanoparticles(FA-CSNP/MTX). Drug dissolution testing, CCK-8 method, and confocal microscopy were used to detect their controlled-release capability in different situations and the specific uptake by HONE1 cells. The experimental results show that the nanoparticles have uniform size distribution of 48-58 nm. The highest encapsulation rate of the particles on mitoxantrone hydrochloride(MTX) is(77.5±1.9)%, and the drug loading efficiency is(18.4±0.4)%. The sustained release effect, cell growth inhibition activity and targeting effect of the FA-CS/MTX nanoparticles are good in artificial gastric fluid and intestinal fluid. It is demonstrated that the FA-CSNP system is a potentially useful system for the targeted delivery of anticancer drug MTX.
文摘Thrombospondin 4(THBS4;TSP4),a crucial component of the extracellular matrix(ECM),serves as an important regulator of tissue homeostasis and various pathophysiological processes.As a member of the evolutionarily conserved thrombospondin family,THBS4 is a multidomain adhesive glycoprotein characterized by six distinct structural domains that mediate its diverse biological functions.Through dynamic interactions with various ECM components,THBS4 plays pivotal roles in cell adhesion,proliferation,inflammation regulation,and tissue remodeling,establishing it as a key modulator of microenvironmental organization.The transcription and translation of THBS4 gene,as well as the activity of the THBS4 protein,are tightly regulated by multiple signaling pathways and extracellular cues.Positive regulators of THBS4 include transforming growth factorβ(TGF-β),interferonγ(IFNγ),granulocyte-macrophage colony-stimulating factor(GM-CSF),bone morphogenetic proteins(BMP12/13),and other regulatory factors(such as B4GALNT1,ITGA2/ITGB1,PDGFRβ,etc.),which upregulate THBS4 at the mRNA and/or protein level.Conversely,oxidized low-density lipoprotein(OXLDL)acts as a potent negative regulator of THBS4.This intricate regulatory network ensures precise spatial and temporal control of THBS4 expression in response to diverse physiological and pathological stimuli.Functionally,THBS4 acts as a critical signaling hub,influencing multiple downstream pathways essential for cellular behavior and tissue homeostasis.The best-characterized pathways include:(1)the PI3K/AKT/mTOR axis,which THBS4 modulates through both direct and indirect interactions with integrins and growth factor receptors;(2)Wnt/β-catenin signaling,where THBS4 functions as either an activator or inhibitor depending on the cellular context;(3)the suppression of DBET/TRIM69,contributing to its diverse regulatory roles.These signaling connections position THBS4 as a master regulator of cellular responses to microenvironmental changes.Substantial evidence links aberrant THBS4 expression to a range of pathological conditions,including neoplastic diseases,cardiovascular disorders,fibrotic conditions,neurodegenerative diseases,musculoskeletal disorders,and atopic dermatitis.In cancer biology,THBS4 exhibits context-dependent roles,functioning either as a tumor suppressor or promoter depending on the tumor type and microenvironment.In the cardiovascular system,THBS4 contributes to both adaptive remodeling and maladaptive fibrotic responses.Its involvement in fibrotic diseases arises from its ability to regulate ECM deposition and turnover.The diagnostic and therapeutic potential of THBS4 is particularly promising in oncology and cardiovascular medicine.As a biomarker,THBS4 expression patterns correlate significantly with disease progression and patient outcomes.Therapeutically,targeting THBS4-mediated pathways offers novel opportunities for precision medicine approaches,including anti-fibrotic therapies,modulation of the tumor microenvironment,and enhancement of tissue repair.This comprehensive review systematically explores three key aspects of THBS4 research:(1)the fundamental biological functions of THBS4 in ECM organization;(2)its mechanistic involvement in various disease pathologies;(3)its emerging potential as both a diagnostic biomarker and therapeutic target.By integrating recent insights from molecular studies,animal models,and clinical investigations,this review provides a framework for understanding the multifaceted roles of THBS4 in health and disease.The synthesis of current knowledge highlights critical research gaps and future directions for exploring THBS4-targeted interventions across multiple disease contexts.Given its unique position at the intersection of ECM biology and cellular signaling,THBS4 represents a promising frontier for the development of novel diagnostic tools and therapeutic strategies in precision medicine.
文摘The YOLOv8 model faces challenges with dense target distribution and small size,resulting in lower accuracy in dense small target detection.To address these issues,an improved small target detection algorithm based on the YOLOv8 model was proposed in this paper.Firstly,the Global Attention Module(GAM)was introduced to enhance data prediction capability and model expression ability.Secondly,the Space-to-Depth(SPD)module was incorporated into the backbone network for fine-grained feature information learning to mitigate feature information loss due to down-sampling.Finally,a 160 pixels×160 pixels feature layer was added to expand small target feature information and effectively reduce instances of missed targets.Experimental validation on the public VisDrone2019 UAV small target detaset demonstrated that the proposed model achieves significant performance improvement in small target detection tasks compared to existing models,exhibiting higher accuracy.
文摘Oral squamous cell carcinoma(OSCC)is the most common head and neck malignancy worldwide,accounting for more than 90%of all oral cancers,and is characterized by high invasiveness and poor long-term prognosis.Its etiology is multifactorial,involving tobacco use,alcohol consumption,and human papillomavirus(HPV)infection.Oral leukoplakia and erythroplakia are the main precancerous lesions lesions,with oral leukoplakia being the most common.Both OSCC and premalignant lesions are closely associated with aberrant activation of multiple signaling pathways.Post-translational modifications(such as ubiquitination and deubiquitination)play key roles in regulating these pathways by controlling protein stability and activity.Growing evidence indicates that dysregulated ubiquitination/deubiquitination can mediate OSCC initiation and progression via aberrant activation of signaling pathways.The ubiquitination/deubiquitination process mainly involves E3 ligases(E3s)that catalyze substrate ubiquitination,deubiquitinating enzymes(DUBs)that remove ubiquitin chains,and the 26S proteasome complex that degrades ubiquitinated substrates.Abnormal expression or mutation of E3s and DUBs can lead to altered stability of critical tumorrelated proteins,thereby driving OSCC initiation and progression.Therefore,understanding the aberrantly activated signaling pathways in OSCC and the ubiquitination/deubiquitination mechanisms within these pathways will help elucidate the molecular mechanisms and improve OSCC treatment by targeting relevant components.Here,we summarize four aberrantly activated signaling pathways in OSCC―the PI3K/AKT/mTOR pathway,Wnt/β-catenin pathway,Hippo pathway,and canonical NF-κB pathway―and systematically review the regulatory mechanisms of ubiquitination/deubiquitination within these pathways,along with potential drug targets.PI3K/AKT/mTOR pathway is aberrantly activated in approximately 70%of OSCC cases.It is modulated by E3s(e.g.,FBXW7 and NEDD4)and DUBs(e.g.,USP7 and USP10):FBXW7 and USP10 inhibit signaling,while NEDD4 and USP7 potentiate it.Aberrant activation of the Wnt/β-catenin pathway leads toβ-catenin nuclear translocation and induction of cell proliferation.This pathway is modulated by E3s(e.g.,c-Cbl and RNF43)and DUBs(e.g.,USP9X and USP20):c-Cbl and RNF43 inhibit signaling,while USP9X and USP20 potentiate it.Hippo pathway inactivation permits YAP/TAZ to enter the nucleus and promotes cancer cell metastasis.This pathway is modulated by E3s(e.g.,CRL4^(DCAF1) and SIAH2)and DUBs(e.g.,USP1 and USP21):CRL4^(DCAF1) and SIAH2 inhibit signaling,while USP1 and USP21 potentiate it.Persistent activation of the canonical NF-κB pathway is associated with an inflammatory microenvironment and chemotherapy resistance.This pathway is modulated by E3s(e.g.,TRAF6 and LUBAC)and DUBs(e.g.,A20 and CYLD):A20 and CYLD inhibit signaling,while TRAF6 and LUBAC potentiate it.Targeting these E3s and DUBs provides directions for OSCC drug research.Small-molecule inhibitors such as YCH2823(a USP7 inhibitor),GSK2643943A(a USP20 inhibitor),and HOIPIN-8(a LUBAC inhibitor)have shown promising antitumor activity in preclinical models;PROTAC molecules,by binding to surface sites of target proteins and recruiting E3s,achieve targeted ubiquitination and degradation of proteins insensitive to small-molecule inhibitors,for example,PU7-1-mediated USP7 degradation,offering new strategies to overcome traditional drug limitations.Currently,NX-1607(a Cbl-b inhibitor)has entered phase I clinical trials,with preliminary results confirming its safety and antitumor activity.Future research on aberrant E3s and DUBs in OSCC and the development of highly specific inhibitors will be of great significance for OSCC precision therapy.
文摘In recent years,with the development of synthetic aperture radar(SAR)technology and the widespread application of deep learning,lightweight detection of SAR images has emerged as a research direction.The ultimate goal is to reduce computational and storage requirements while ensuring detection accuracy and reliability,making it an ideal choice for achieving rapid response and efficient processing.In this regard,a lightweight SAR ship target detection algorithm based on YOLOv8 was proposed in this study.Firstly,the C2f-Sc module was designed by fusing the C2f in the backbone network with the ScConv to reduce spatial redundancy and channel redundancy between features in convolutional neural networks.At the same time,the Ghost module was introduced into the neck network to effectively reduce model parameters and computational complexity.A relatively lightweight EMA attention mechanism was added to the neck network to promote the effective fusion of features at different levels.Experimental results showed that the Parameters and GFLOPs of the improved model are reduced by 8.5%and 7.0%when mAP@0.5 and mAP@0.5:0.95 are increased by 0.7%and 1.8%,respectively.It makes the model lightweight and improves the detection accuracy,which has certain application value.
基金Supported by the Key Laboratory Fund for Equipment Pre-Research(6142207210202)。
文摘Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small target detection method based on the tensor nuclear norm and direction residual weighting was proposed.Based on converting the infrared image into an infrared patch tensor model,from the perspective of the low-rank nature of the background tensor,and taking advantage of the difference in contrast between the background and the target in different directions,we designed a double-neighborhood local contrast based on direction residual weighting method(DNLCDRW)combined with the partial sum of tensor nuclear norm(PSTNN)to achieve effective background suppression and recovery of infrared small targets.Experiments show that the algorithm is effective in suppressing the background and improving the detection ability of the target.
文摘Momordica antiviral protein 30 kD(MAP30)is a type I ribosome-inactivating protein(RIP)with antibacterial,anti-HIV and antitumor activities but lacks the ability to target tumor cells.To increase its tumor-targeting ability,the arginine-glycine-aspartic(RGD)peptide and the epidermal growth factor receptor interference(EGFRi)peptide were fused with MAP30,which was named ELRL-MAP30.The efficiency of targeted therapy for triple-negative breast cancer(TNBC)MDA-MB-231 cells,which lack the expression of estrogen receptor(ER),Progesterone receptor(PgR)and human epidermal growth factor receptor-2(HER2),is limited.In this study,we focus on exploring the effect and mechanism of ELRL-MAP30 on TNBC MDA-MB-231 cells.First,we discovered that ELRL-MAP30 significantly inhibited the migration and invasion of MDA-MB-231 cells and induced MDA-MB-231 cell apoptosis.Moreover,ELRL-MAP30 treatment resulted in a significant increase in Bax expression and a decrease in Bcl-2 expression.Furthermore,ELRL-MAP30 triggered apoptosis via the Fak/EGFR/Erk and Ilk/Akt signaling pathways.In addition,recombinant ELRL-MAP30 can inhibit chicken embryonic angiogenesis,and also inhibit the tube formation ability of human umbilical vein endothelial cells(HUVECs),indicating its potential therapeutic effects on tumor angiogenesis.Collectively,these results indicate that ELRL-MAP30 has significant tumor-targeting properties in MDA-MB-231 cancer cells and reveals potential therapeutic effects on angiogenesis.These findings indicate the potential role of ELRL-MAP30 in the targeted treatment of the TNBC cell line MDA-MB-231.
文摘A measurement system for the scattering characteristics of warhead fragments based on high-speed imaging systems offers advantages such as simple deployment,flexible maneuverability,and high spatiotemporal resolution,enabling the acquisition of full-process data of the fragment scattering process.However,mismatches between camera frame rates and target velocities can lead to long motion blur tails of high-speed fragment targets,resulting in low signal-to-noise ratios and rendering conventional detection algorithms ineffective in dynamic strong interference testing environments.In this study,we propose a detection framework centered on dynamic strong interference disturbance signal separation and suppression.We introduce a mixture Gaussian model constrained under a joint spatialtemporal-transform domain Dirichlet process,combined with total variation regularization to achieve disturbance signal suppression.Experimental results demonstrate that the proposed disturbance suppression method can be integrated with certain conventional motion target detection tasks,enabling adaptation to real-world data to a certain extent.Moreover,we provide a specific implementation of this process,which achieves a detection rate close to 100%with an approximate 0%false alarm rate in multiple sets of real target field test data.This research effectively advances the development of the field of damage parameter testing.
基金supported by the National Natural Science Foundation of China(Grant Nos.12102201,U2341244).
文摘An experimental and finite element simulation investigation are conducted to study the deformation patterns of steel targets during the penetration process of tungsten alloy long rods,as well as the influence of strength of the target on the deformation patterns.The experimental results revealed slight mass loss in the first layer of the steel target during the transient entrance phase,with an extremely negligible loss in target mass during the quasi-steady penetration phase.The results of macro-analysis,micro-analysis and simulation show that the eroded target material migrated towards the periphery of the crater,causing an increase in the target's thickness,remained within the target,instead of flowing out of the crater.Therefore,the process of long rods penetrating the metal target is considered as a process of backward extrusion.By combining the backward extrusion theory with energy conservation,a penetration depth model for long rods penetrating a metal target,taking into account both the diameter of the crater and the friction coefficient between the rod and the target,has been established.Although the model is not yet perfect,it innovatively applies the principles of solid mechanics to the study of long rod penetration.Additionally,it takes into account the friction coefficient between the rod and the target during the penetration process.Therefore,this model provides a new research direction for future studies on long rod penetration.
基金the National Natural Science Foundation of China(Grant Nos.62303348 and 62173242)the Aeronautical Science Foundation of China(Grant No.2024M071048002)the National Science Fund for Distinguished Young Scholars(Grant No.62225308)to provide fund for conducting experiments.
文摘Multiple quadrotors target encirclement is widely used in the intelligent field,as it can effectively monitor and control target behavior.However,it faces the danger of collision,as well as difficulties in localization and tracking.Therefore,we propose a complete target encirclement method.Firstly,based on Hooke's law,a collision avoidance controller is designed to maintain a safe flying distance among quadrotors.Then,based on the consensus theory,a formation tracking controller is designed to meet the requirements of formation transformation and encirclement tasks,and a stability proof based on Lyapunov was provided.Besides,the target detection is designed based on YOLOv5s,and the target location model is constructed based on the principle of pinhole projection and triangle similarity.Finally,we conducted experiments on the built platform,with 3 reconnaissance quadrotors detecting and localization 3 target vehicles and 7 hunter quadrotors tracking them.The results show that the minimum average error for localization targets with reconnaissance quadrotors can reach 0.1354 m,while the minimum average error for tracking with hunter quadrotors is only 0.2960 m.No quadrotors collision occurred in the whole formation transformation and tracking experiment.In addition,compared with the advanced methods,the proposed method has better performance.
文摘Accurate target angle estimation is one of the chal-lenges for wideband radars due to the fact that target occupies multiple range bins,resulting in lower energy or signal to noise ratio in a single range bin.This paper proposes a processing technique for enhanced accuracy of target angle estimates for wideband monopulse radars.Firstly,to accumulate the energy of the received echo signals from different scatterers on a target,the phase difference between different scatterers on a target is estimated using the minimum entropy phase estimation method combining with the correlation between adjacent pulses.Then,the monopulse ratio is obtained by using the signals from the accumulated sum and difference channels.The target angle is estimated by weighting the accumulated echo energy for accu-racy enhancement.Experimental results based on both numeri-cal simulation and measured data are presented to validate the effectiveness of the proposed technique.
基金supported by the National Natural Science Foundation of China(Grant No.62203362)the Natural Science Basic Research Program of Shaanxi(Grant No.2023-JC-QN-0569)。
文摘A situation maintenance-based cooperative guidance strategy is proposed to intercept a high-speed and high-maneuverability target via inferior missiles.Reachability and relative motion analyses are conducted to develop and pursue virtual targets,respectively.A two-stage guidance strategy under nonlinear kinematics is developed on the basis of virtual targets.The first stage optimizes the coverage and collision situation by pursuing virtual targets under specific angular constraints.The second stage subsequently intercepts the superior target based on the handover condition optimized by the first stage.Numerical simulation results are provided to compare the effectiveness and superiority of the proposed strategy with those of the reachability-based cooperative strategy(RCS),coverage-based cooperative guidance(CBCG)and augmented proportional navigation(APN)under various maneuvering modes.
基金supported by the National Natural Science Foundation of China(Grant Nos.52178515 and 12472399)。
文摘With the application of hypervelocity weapons in warfare,comprehensively evaluating their destructive effects is of particular interest for protective engineering.Existing studies mostly focused on the depth of penetration by hypervelocity projectile,while investigation on stress waves associated with hypervelocity penetration was very limited.To clarify the generation and propagation of stress waves in concrete targets induced by hypervelocity projectile penetration,in the present study,six spherical projectile penetration tests on concrete targets were firstly conducted with projectile velocity ranged from 1875 m/s to 3940 m/s,in which the stress waves were carefully measured by the PVDF transducers.Then corresponding numerical models were developed and validated,and based on the validated numerical model the mechanisms of generation and propagation of stress waves were clarified.It was found that the stress waves observed during hypervelocity penetration are generated by the continuous interactions of projectile and target during penetration,and have unique characteristics such as the directionality and the"two peaks"phenomenon when compared with the stress waves generated by charge explosion.Finally,the effects of projectile velocity,projectile material,and target strength on the stress waves below the penetration depth we re numerically investigated,and two important indexes for evaluating the stress waves by hypervelocity penetration were proposed.
基金supported by the National Natural Science Foun-dation of China(Grant No.52275099).
文摘The acquisition,tracking,and pointing(ATP)system is widely used in target tracking,counter-UAV operations,and other related fields.As UAV technology develops,there is a growing demand to enhance the tracking capabilities of ATP systems.However,in practical applications,ATP systems face various design constraints and functional limitations,making it infeasible to indefinitely improve hardware performance to meet tracking requirements.As a result,tracking algorithms are required to execute increasingly complex tasks.This study introduces a multi-rate feedforward predictive controller to address issues such as low image feedback frequency and significant delays in ATP systems,which lead to tracking jitter,poor tracking performance,low precision,and target loss.At the same time,the pro-posed approach aims to improve the tracking capabilities of ATP systems for high-speed and highly maneuverable targets under conditions of low sampling feedback rates and high feedback delays.The method suggested is also characterized by its low order,fast response,and robustness to model parameter variations.In this study,an actual ATP system is built for target tracking test,and the proposed algorithm is fully validated in terms of simulation and actual system application verification.Results from both simulations and experiments demonstrate that the method effectively compensates for delays and low sampling rates.For targets with relative angular velocities ranging from 0 to 90°/s and angular accelerations between 0 and 470°/s^(2),the system improved tracking accuracy by 70.0%-89.9%at a sampling frequency of 50 Hz and a delay of 30 m s.Moreover,the compensation algorithm demonstrated consistent performance across actuators with varying characteristics,further confirming its robustness to model insensitivity.In summary,the proposed algorithm considerably enhances the tracking accuracy and capability of ATP systems for high-speed and highly maneuverable targets,reducing the probability of target loss from high speed.This approach offers a practical solution for future multi-target tracking across diverse operational scenarios.
文摘This paper proposes a distributed event-triggered control(ETC)framework to address cooperative target fencing challenges in UAV swarm.The proposed architecture eliminates the reliance on preset formation parameters while achieving multi-objective cooperative control for target fencing,network connectivity preservation,collision avoidance,and communication efficiency optimization.Firstly,a differential state observer is constructed to obtain the target's unmeasurable states.Secondly,leveraging swarm selforganization principles,a geometric-constraint-free distributed fencing controller is designed by integrating potential field methods with consensus theory.The controller dynamically adjusts inter-UAV distances via single potential function,enabling coordinated optimization of persistent network connectivity and collision-free motion during target fencing.Thirdly,a dual-threshold ETC mechanism based on velocity consensus deviation and fencing error is proposed,which can be triggered based on task features to dynamically adjust the communication frequency,significantly reduce the communication burden and exclude Zeno behavior.Theoretical analysis demonstrates the stability of closed-loop systems.Multi-scenario simulations show that the proposed method can achieve robust fencing under target maneuverability,partial UAV failures,and communication disturbances.
基金financial support provided by the Natural Science Foundation of Hunan Province of China(Grant No.2021JJ10045)the Open Research Subject of State Key Laboratory of Intelligent Game(Grant No.ZBKF-24-01)+1 种基金the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20240989)the China Postdoctoral Science Foundation(Grant No.2024M754304)。
文摘Unmanned aerial vehicles(UAVs)have become crucial tools in moving target tracking due to their agility and ability to operate in complex,dynamic environments.UAVs must meet several requirements to achieve stable tracking,including maintaining continuous target visibility amidst occlusions,ensuring flight safety,and achieving smooth trajectory planning.This paper reviews the latest advancements in UAV-based target tracking,highlighting information prediction,tracking strategies,and swarm cooperation.To address challenges including target visibility and occlusion,real-time prediction and tracking in dynamic environments,flight safety and coordination,resource management and energy efficiency,the paper identifies future research directions aimed at improving the performance,reliability,and scalability of UAV tracking system.
