Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance protei...Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.展开更多
The nervous system processes a vast amount of information,performing computations that underlie perception,cognition,and behavior.During development,neuronal guidance genes,which encode extracellular cues,their recept...The nervous system processes a vast amount of information,performing computations that underlie perception,cognition,and behavior.During development,neuronal guidance genes,which encode extracellular cues,their receptors,and downstream signal transducers,organize neural wiring to generate the complex architecture of the nervous system.It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system.This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system.Supporting this view,these pathways continue to regulate synaptic connectivity,plasticity,and remodeling,and overall brain homeostasis throughout adulthood.Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders.Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified,emerging evidence points to several common themes,including dysfunction in neurons,microglia,astrocytes,and endothelial cells,along with dysregulation of neuron-microglia-astrocyte,neuroimmune,and neurovascular interactions.In this review,we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions.For instance,recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation.We discuss the challenges ahead,along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases.Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions.Specifically,we examine the crosstalk between neuronal guidance signaling and TREM2,a master regulator of microglial function,in the context of pathogenic protein aggregates.It is well-established that age is a major risk factor for neurodegeneration.Future research should address how aging and neuronal guidance signaling interact to influence an individual’s susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.展开更多
Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warf...Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warfare.This study presents a systematic review and analysis of current research on cooperative guidance.First,a bibliometric analysis is conducted on 513 articles using the Scopus database and CiteSpace software to assess keyword clustering,keyword cooccurrence,and keyword burst,and to later visualize the results.Second,fundamental theories of cooperative guidance,including relative motion modeling methods,algebraic graph theory,and multi-agent consensus theory,are summarized.Subsequently,an overview of current cooperative laws and corresponding analysis methods is provided,with categorization based on the cooperative structure and convergence performance.Finally,we summarize current research developments based on five perspectives and propose a developmental framework based on five layers(cyber,physical,decision,information,and system),discussing potential future advancements in cooperative terminal guidance.This framework emphasizes five key areas of research:networked,heterogeneous,integrated,intelligent,and group cooperations,with the goal of offering trends and insights for futurework.展开更多
Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduit...Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.展开更多
A segmented predictor-corrector method is proposed for hypersonic glide vehicles to address the issue of the slow computational speed of obtaining guidance commands using the traditional predictor-corrector guidance m...A segmented predictor-corrector method is proposed for hypersonic glide vehicles to address the issue of the slow computational speed of obtaining guidance commands using the traditional predictor-corrector guidance method.Firstly,an altitude-energy profile is designed,and the bank angle is derived analytically as the initial iteration value for the predictor-corrector method.The predictor-corrector guidance method has been improved by deriving an analytical form for predicting the range-to-go error,which greatly accelerates the iterative speed.Then,a segmented guidance algorithm is proposed.The above analytically predictor-corrector guidance method is adopted when the energy exceeds an energy threshold.When the energy is less than the threshold,the equidistant test method is used to calculate the bank angle command,which ensures guidance accuracy as well as computational efficiency.Additionally,an adaptive guidance cycle strategy is applied to reduce the computational time of the reentry guidance trajectory.Finally,the accuracy and robustness of the proposed method are verified through a series of simulations and Monte-Carlo experiments.Compared with the traditional integral method,the proposed method requires 75%less computation time on average and achieves a lower landing error.展开更多
In air combat,one effective way to counter an incoming missile attacking an aircraft is to launch a defense missile compared with traditional passive defense strategies such as decoy and electronic countermeasures.To ...In air combat,one effective way to counter an incoming missile attacking an aircraft is to launch a defense missile compared with traditional passive defense strategies such as decoy and electronic countermeasures.To address this issue,this paper proposes a three-body cooperative active defense guidance law with overload constraints from the perspective of a small speed ratio.First,a cooperative guidance-oriented model for active defense is established and linearized to provide a foundation for the design of the guidance law.Then,the essential quantity known as Zero-Effort-Miss(ZEM)is analyzed during the engagement process.In order to minimize the influence of inaccurate estimates of remaining flight time in the ZEM,the concept of Zero-Effort-Velocity(ZEV)is introduced.Subsequently,utilizing the sliding mode control method,the guidance law is designed by selecting the ZEM and ZEV as sliding mode surfaces,combined with the fast power reaching law,and its finite-time stability is analyzed using the Lyapunov method.Furthermore,to quantitatively evaluate the performance of the proposed active defense guidance law,the interception rendezvous angle index is introduced.The proposed active defense guidance law considers integrating information from the incoming missile,aircraft,and defense missile with fewer simplifications and assumptions,and ensures that the aircraft is effectively protected with less overload required for the defense missile.Finally,simulation experiments demonstrate the effectiveness and adaptability of the proposed active defense guidance law.展开更多
Earth-to-Moon missions with low thrust-to-weight ratios present unique challenges for exoatmospheric guidance,and the existing algorithms are ineffective for the unprecedentedly long burn arcs and high orbital eccentr...Earth-to-Moon missions with low thrust-to-weight ratios present unique challenges for exoatmospheric guidance,and the existing algorithms are ineffective for the unprecedentedly long burn arcs and high orbital eccentricities.To address these challenges,a Long Burn Arc Powered Explicit Guidance(LBA-PEG)algorithm is developed and compared with the existing algorithms.In the proposed LBA-PEG algorithm,a fully numerical thrust prediction method is developed to accurately predict the highly nonlinear thrust effects over long burn arcs.Moreover,a real-time Newton correction method is proposed to correct the orbit injection point,remedying the position-velocity coupling induced by high orbital eccentricities.The comparison between the proposed algorithm and the existing algorithm shows that the proposed algorithm surpasses the existing ones by significantly enhancing fuel efficiency and improving tolerance to thrust decrease.The proposed LBA-PEG algorithm can adapt to a 65%thrust decrease,which is 12%–22%larger than that of the existing algorithms,and it can still reliably converge and complete the guidance mission even when the length of the burn arc exceeds 90°.The proposed LBA-PEG highlights the algorithm's adaptability for long burn arc missions,especially in critical scenarios such as manned Earth-to-Moon missions.展开更多
In this paper,a novel guidance law is proposed which can achieve the desired impact speed and angle simultaneously for unpowered gliding vehicles.A guidance law with only impact angle constraint is used to produce the...In this paper,a novel guidance law is proposed which can achieve the desired impact speed and angle simultaneously for unpowered gliding vehicles.A guidance law with only impact angle constraint is used to produce the guidance profile,and its convergence in the varying speed scenario is proved.A relationship between flight states,guidance input and impact speed is established.By applying the fixed-time convergence control theory of error dynamics,an impact speed corrector is built with the above guidance profile,which can implement impact speed correction without affecting the impact angle constraint.Numerical simulations with various impact speed and angle constraints are conducted to demonstrate the performance of the proposed guidance law,and the robustness is also verified by Monte Carlo tests.展开更多
Current treatments for epilepsy can only manage the symptoms of the condition but cannot alter the initial onset or halt the progression of the disease. Consequently, it is crucial to identify drugs that can target no...Current treatments for epilepsy can only manage the symptoms of the condition but cannot alter the initial onset or halt the progression of the disease. Consequently, it is crucial to identify drugs that can target novel cellular and molecular mechanisms and mechanisms of action. Increasing evidence suggests that axon guidance molecules play a role in the structural and functional modifications of neural networks and that the dysregulation of these molecules is associated with epilepsy susceptibility. In this review, we discuss the essential role of axon guidance molecules in neuronal activity in patients with epilepsy as well as the impact of these molecules on synaptic plasticity and brain tissue remodeling. Furthermore, we examine the relationship between axon guidance molecules and neuroinflammation, as well as the structural changes in specific brain regions that contribute to the development of epilepsy. Ample evidence indicates that axon guidance molecules, including semaphorins and ephrins, play a fundamental role in guiding axon growth and the establishment of synaptic connections. Deviations in their expression or function can disrupt neuronal connections, ultimately leading to epileptic seizures. The remodeling of neural networks is a significant characteristic of epilepsy, with axon guidance molecules playing a role in the dynamic reorganization of neural circuits. This, in turn, affects synapse formation and elimination. Dysregulation of these molecules can upset the delicate balance between excitation and inhibition within a neural network, thereby increasing the risk of overexcitation and the development of epilepsy. Inflammatory signals can regulate the expression and function of axon guidance molecules, thus influencing axonal growth, axon orientation, and synaptic plasticity. The dysregulation of neuroinflammation can intensify neuronal dysfunction and contribute to the occurrence of epilepsy. This review delves into the mechanisms associated with the pathogenicity of axon guidance molecules in epilepsy, offering a valuable reference for the exploration of therapeutic targets and presenting a fresh perspective on treatment strategies for this condition.展开更多
Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the ...Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.展开更多
Flexible lander,composed of multiple nodes connected by flexible material,can reducethe bouncing and overturning during the asteroid landing.To satisfy the complex constraints inthe node cooperation of the flexible la...Flexible lander,composed of multiple nodes connected by flexible material,can reducethe bouncing and overturning during the asteroid landing.To satisfy the complex constraints inthe node cooperation of the flexible landing,an intelligent cooperative guidance method is pro-posed.The method consists of a double-layer cooperative guidance structure,a guidance parameterdetermination approach,and an action priority strategy.The double-layer contains a basic guid-ance used to satisfy the terminal state constraints,and a compensatory guidance used to satisfythe lander's attitude constraint.For the compensatory guidance,the parameters are determinedby multi-agent system,which are trained according to the performance index of flexible landing tra-jectories.The action priority strategy is used to reduce the detrimental effect of parameter inconsis-tency on the node cooperation.The simulation of flexible landing shows that the cooperativeguidance method is effective in improving the landing accuracy while satisfying the constraints.Meanwhile,the method is robust to the disturbance in the navigation and control.展开更多
Once a train stops in a tunnel section and requires emergency evacuation,the large distance between stations and long walking distances in the underground spaces of suburban railway systems pose potential risks to the...Once a train stops in a tunnel section and requires emergency evacuation,the large distance between stations and long walking distances in the underground spaces of suburban railway systems pose potential risks to the evacuation process on tunnel platforms,especially in complex environments.This study utilized Virtual Reality(VR)technology to construct a virtual experimental platform for tunnel evacuation in suburban railway systems,simulating different combinations of smoke and obstacle conditions.By requiring participants to wear VR glasses and walk on an omnidirectional treadmill for moving,as well as complete psychological questionnaires,the study reveals the influences of No Guiding(NG)signs,Wall-Guided(WG)signs,and Central axis Guidance(CG)signs on the movement abilities and psychological behaviors of participants contrastively.The results show that either smoke conditions or obstacle positions affect the mental stress of participants,and the guidance sign has a positive effect on reducing the mental stress.There is an inverse relationship between mental stress and movement abilities.WG and CG signs respectively lead participants to walk closer to walls and along the central axis,which is conducive to reducing the variation in participants’behavior characteristics when circumventing obstacles on the wall side or track side under smoke conditions,respectively.Additionally,CG signs reduce the speed fluctuations of participants before circumventing obstacles,improving the stability of the distance from the wall and speed under smoke conditions,compared to NG and WG signs.These findings contribute to understanding the evacuation psychological-behavioral-movement characteristics of pedestrians on evacuation platforms in suburban railway tunnels and provide a basis for improving the safety design of evacuation guidance signs.展开更多
Objective:To investigate the application effects of intelligent guidance systems in optimizing health check-up process management.Methods:A total of 400 examinees who underwent physical examinations at the hospital’s...Objective:To investigate the application effects of intelligent guidance systems in optimizing health check-up process management.Methods:A total of 400 examinees who underwent physical examinations at the hospital’s Health Management Center from January to December 2024 were randomly divided into a control group(200 cases)and an observation group(200 cases).The control group used traditional manual guidance methods,while the observation group employed the intelligent guidance system.The study compared two groups in terms of completion time,waiting time for each procedure,check-up efficiency scores,examinee satisfaction,and report issuance time.Results:The overall examination time in the observation group(85.3±12.7 minutes)was significantly shorter than that in the control group(142.6±18.5 minutes)(P<0.01);average waiting time per procedure decreased by 62.4%;check-up efficiency scores(8.9±0.8 points)were significantly higher than those in the control group(5.2±1.1 points)(P<0.01);satisfaction reached 96.5%,significantly higher than the control group’s 78.0%(P<0.01);and report issuance time was advanced by 1.5 days.Conclusion:Intelligent guidance systems can significantly optimize check-up processes,improve work efficiency,and examinee satisfaction,demonstrating significant clinical application value.展开更多
This paper presents a fixed-time cooperative gui-dance method with impact angle constraints for multiple flight vehicles (MFV) to address the challenges of intercepting large maneuvering targets with difficulty and lo...This paper presents a fixed-time cooperative gui-dance method with impact angle constraints for multiple flight vehicles (MFV) to address the challenges of intercepting large maneuvering targets with difficulty and low precision. A coopera-tive guidance model is proposed, transforming the cooperative interception problem into a consensus problem based on the remaining flight time of the flight vehicles. First, the impact angle constraint is converted into the line of sight (LOS) angle con-straint, and a new fixed-time convergent non-singular terminal sliding surface is introduced, which resolves the singularity issue of the traditional sliding surfaces. With this approach, LOS angle rate and normal overloads can converge in fixed time, ensuring that the upper bound of the system convergence time is not affected by the initial value of the system. Furthermore, the maneuvering movement of the target is considered as a system disturbance, and an extended state observer is employed to estimate and compensate for it in the guidance law. Lastly, by applying consensus theory and distributed communication topology, the remaining flight time of each flight vehicle is syn-chronized to ensure that they intercept the target simulta-neously with different impact angles. Simulation experiments are conducted to validate the effectiveness of the proposed cooper-ative interception and guidance method.展开更多
With the continuous increase in the number of university graduates and the intensification of structural contradictions in the job market,employment guidance in local universities faces significant challenges.Based on...With the continuous increase in the number of university graduates and the intensification of structural contradictions in the job market,employment guidance in local universities faces significant challenges.Based on the theory of digital transformation in education and the application framework of artificial intelligence(AI),this paper explores pathways for AI to enhance the quality of employment guidance in local universities,using employment data of university graduates in Sichuan Province and relevant policy orientations.Through case analysis,survey data,and theoretical research,the study finds that AI can optimize employment guidance processes and improve job-person matching efficiency through intelligent matching,personalized recommendations,and data-driven decision-making mechanisms,thereby facilitating the alignment between talent cultivation in universities and industry demands.The study proposes the construction of an“AI+Employment”ecosystem,the refinement of intelligent evaluation models,and the deepening of university-enterprise collaboration,providing theoretical foundations and practical references for the reform of local university employment guidance systems.展开更多
The tumor microenvironment(TME)-activatable probes have proven effective in enhancing the signalto-background ratio(SBR)for precise fluorescence imaging in tumor diagnosis.However,many fluorophores have suboptimal emi...The tumor microenvironment(TME)-activatable probes have proven effective in enhancing the signalto-background ratio(SBR)for precise fluorescence imaging in tumor diagnosis.However,many fluorophores have suboptimal emission spectra and a short Stokes shift,which may lead to overlap with bioautofluorescence,excitation,and emission spectra,limiting their use in intraoperative guidance.Herein,aγ-glutathione(GSH)responsive near-infrared(NIR)BODIPY probe,named“Pro-Dye”was synthesized with a large Stokes shift of 91 nm.The Pro-Dye can be rapidly and specifically activated by high concentrations of GSH both in solution and inside cancer cells,while remaining inactive in normal cells(Human umbilical vein endothelial cells,HUVECs).The Pro-Dye was further encapsulated by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(polyethylene glycol)-5000(DSPE-PEG5000)to form Pro-Dye nanoparticles(NPs),making it water-dispersible for in vivo application.In vivo fluorescence imaging demonstrated that Pro-Dye NPs can accumulate at the tumor and exhibit an improved SBR compared to the“alwayson”probe(Dye NPs).Moreover,the tumor can be precisely resected under the real-time guidance of fluorescence imaging of Pro-Dye NPs,showing a well-defined tumor margin.展开更多
A cooperative guidance law is proposed in a two-ontwo engagement scenario with large-heading-errors by choosing zero-effort miss distance as a sliding surface,which consists of an attacker,a protector,a defender,and a...A cooperative guidance law is proposed in a two-ontwo engagement scenario with large-heading-errors by choosing zero-effort miss distance as a sliding surface,which consists of an attacker,a protector,a defender,and a target,based on fixed-time sliding mode control theory.Based on the nonlinear method of fixed-time sliding mode control,the performance of the cooperative guidance law remains satisfactory even with large-heading-errors scenarios where the linearization-based approaches might be invalid.By virtue of this law,the attacker pursues the target with the assistance of the protector,which can intercept the defender in the engagement scenario.Furthermore,if the attacker is intercepted by the defender,the guidance law of the protector could guarantee that the protector attacks the target.A robust adaptive term is included in the guidance law to deal with the case of the unknown disturbance upper bound of the defender-target team.Finally,the feasibility of the guidance law is verified by nonlinear numerical simulations,and the superiority of it is illustrated by comparing with the linearization guidance law.展开更多
This paper proposes a distributed nonsingular cooperative guidance law for multiple flight vehicles with Field-of-View(FOV)constraints.First,a novel time-to-go estimation is developed based on a FOV-constrained Propor...This paper proposes a distributed nonsingular cooperative guidance law for multiple flight vehicles with Field-of-View(FOV)constraints.First,a novel time-to-go estimation is developed based on a FOV-constrained Proportional Navigation Guidance(FPNG)law.Then,the FPNG law is augmented with a cooperative guidance term to achieve consensus of time-to-go with predefined-time convergence prior to the impact time.A continuous auxiliary function is introduced in the bias term to avoid the singularity of guidance command.Moreover,the proposed guidance law is extended to the three-dimensional guidance scenarios and the moving target with the help of a predicted interception point.Finally,several numerical simulations are conducted,and the results verify the effectiveness,robustness,and advantages of the proposed cooperative guidance law.展开更多
This paper presents a vision-based navigation framework for micro air vehicles(MAVs)operating in confined warehouse environments.To address the trade-off between low localization accuracy in mapless methods and high c...This paper presents a vision-based navigation framework for micro air vehicles(MAVs)operating in confined warehouse environments.To address the trade-off between low localization accuracy in mapless methods and high computational demands in map-based approaches,the proposed system leverages topology-aware path guidance using monocular vision.Navigation is driven by a digital instruction format(DIF)that encodes both the path index and target junction,enabling autonomous navigation without environmental modifications.The framework comprises a cascaded perception-encoding-control pipeline.For structured paths,foreground pixel density trend analysis with sliding window smoothing for robust junction recognition,while lateral proportionalintegral-derivative(PID)control ensures accurate path tracking.For geometric trajectories,the control logic incorporates L-junction triggers,fixed-angle turns,and spatial yaw correction to accommodate sharp corners and curved segments.ROS-Gazebo simulations validate the method’s effectiveness,achieving up to 94.40%junction recognition accuracy(92.01%on average),trajectory tracking errors below 0.1 m,and terminal localization deviations under 0.2 m.These results validate the method’s accuracy,stability,and suitability for computationally constrained MAV platforms in warehouse automation.展开更多
In this article,a three-dimensional cooperative guidance problem for highly maneuvering targets is investigated under the assumption of perfect information.Inspired by the coverage strategy,the cooperative guidance pr...In this article,a three-dimensional cooperative guidance problem for highly maneuvering targets is investigated under the assumption of perfect information.Inspired by the coverage strategy,the cooperative guidance problem is decomposed into one-on-one guidance problems against predictive interception points.To expand the coverage area of each missile,these one-on-one guidance problems are formulated as flight path angle tracking problems,and the optimal error dynamics is extended to derive the guidance law analytically.In addition,through the introduction of the coverage probability model,the dynamic coverage strategy is proposed.The predictive interception points are updated online by maximizing the coverage probability,which aims to achieve successful interception despite variations in target acceleration.Furthermore,a switching strategy of the guidance command is designed for collision avoidance.Simulation results demonstrate that the missile group can cooperatively intercept a highly maneuvering target under the proposed guidance law.展开更多
基金supported by Shenzhen University General Hospital Scientific Research Project,No.SUGH2019QD002Shenzhen Science and Technology Development Foundation,No.20220810173216001(both to ZS).
文摘Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.
基金supported by JSPS(KAKENHI:21K06205,23K06937,24K23419)AMED(to JYK,SaY,TM,SiY,YT,and NH)JYW had long been supported by the NIH.
文摘The nervous system processes a vast amount of information,performing computations that underlie perception,cognition,and behavior.During development,neuronal guidance genes,which encode extracellular cues,their receptors,and downstream signal transducers,organize neural wiring to generate the complex architecture of the nervous system.It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system.This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system.Supporting this view,these pathways continue to regulate synaptic connectivity,plasticity,and remodeling,and overall brain homeostasis throughout adulthood.Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders.Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified,emerging evidence points to several common themes,including dysfunction in neurons,microglia,astrocytes,and endothelial cells,along with dysregulation of neuron-microglia-astrocyte,neuroimmune,and neurovascular interactions.In this review,we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions.For instance,recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation.We discuss the challenges ahead,along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases.Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions.Specifically,we examine the crosstalk between neuronal guidance signaling and TREM2,a master regulator of microglial function,in the context of pathogenic protein aggregates.It is well-established that age is a major risk factor for neurodegeneration.Future research should address how aging and neuronal guidance signaling interact to influence an individual’s susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.
基金supported by the National Natural Science Foundation of China(No.62173274)the National Key R&D Program of China(No.2019YFA0405300)+4 种基金the Natural Science Foundation of Hunan Province of China(Nos.2021JJ10045 and 2025JJ60072)the Open Research Subject of State Key Laboratory of Intelligent Game(No.ZBKF-24-01)the Postdoctoral Fellowship Program of CPSF(No.GZB20240989)the China Postdoctoral Science Foundation(No.2024M754304)the Aeronautical Science Foundation of China(No.2023Z005030001).
文摘Cooperative guidance is a method for achieving combat objectives through information sharing and cooperative effects,and has emerged as a significant research area in the fields of missile guidance and systematic warfare.This study presents a systematic review and analysis of current research on cooperative guidance.First,a bibliometric analysis is conducted on 513 articles using the Scopus database and CiteSpace software to assess keyword clustering,keyword cooccurrence,and keyword burst,and to later visualize the results.Second,fundamental theories of cooperative guidance,including relative motion modeling methods,algebraic graph theory,and multi-agent consensus theory,are summarized.Subsequently,an overview of current cooperative laws and corresponding analysis methods is provided,with categorization based on the cooperative structure and convergence performance.Finally,we summarize current research developments based on five perspectives and propose a developmental framework based on five layers(cyber,physical,decision,information,and system),discussing potential future advancements in cooperative terminal guidance.This framework emphasizes five key areas of research:networked,heterogeneous,integrated,intelligent,and group cooperations,with the goal of offering trends and insights for futurework.
基金supported by the National Natural Science Foundation of China,No.82202718the Natural Science Foundation of Beijing,No.L212050the China Postdoctoral Science Foundation,Nos.2019M664007,2021T140793(all to ZL)。
文摘Autografting is the gold standard for surgical repair of nerve defects>5 mm in length;however,autografting is associated with potential complications at the nerve donor site.As an alternative,nerve guidance conduits may be used.The ideal conduit should be flexible,resistant to kinks and lumen collapse,and provide physical cues to guide nerve regeneration.We designed a novel flexible conduit using electrospinning technology to create fibers on the innermost surface of the nerve guidance conduit and employed melt spinning to align them.Subsequently,we prepared disordered electrospun fibers outside the aligned fibers and helical melt-spun fibers on the outer wall of the electrospun fiber lumen.The presence of aligned fibers on the inner surface can promote the extension of nerve cells along the fibers.The helical melt-spun fibers on the outer surface can enhance resistance to kinking and compression and provide stability.Our novel conduit promoted nerve regeneration and functional recovery in a rat sciatic nerve defect model,suggesting that it has potential for clinical use in human nerve injuries.
基金National Natural Science Foundation of China(Nos.61773387 and 62022061).
文摘A segmented predictor-corrector method is proposed for hypersonic glide vehicles to address the issue of the slow computational speed of obtaining guidance commands using the traditional predictor-corrector guidance method.Firstly,an altitude-energy profile is designed,and the bank angle is derived analytically as the initial iteration value for the predictor-corrector method.The predictor-corrector guidance method has been improved by deriving an analytical form for predicting the range-to-go error,which greatly accelerates the iterative speed.Then,a segmented guidance algorithm is proposed.The above analytically predictor-corrector guidance method is adopted when the energy exceeds an energy threshold.When the energy is less than the threshold,the equidistant test method is used to calculate the bank angle command,which ensures guidance accuracy as well as computational efficiency.Additionally,an adaptive guidance cycle strategy is applied to reduce the computational time of the reentry guidance trajectory.Finally,the accuracy and robustness of the proposed method are verified through a series of simulations and Monte-Carlo experiments.Compared with the traditional integral method,the proposed method requires 75%less computation time on average and achieves a lower landing error.
基金support provided by the National Natural Science Foundation of China(No.62173274)the National Key R&D Program of China(No.2019YFA0405300)+3 种基金the Natural Science Foundation of Hunan Province of China(No.2021JJ10045)Shanghai Aerospace Science and Technology Innovation Fund,China(No.SAST2020-004)Postdoctoral Fellowship Program of CPSF(No.GZB20240989)the Open Research Subject of State Key Laboratory of Intelligent Game,China(No.ZBKF-24-01).
文摘In air combat,one effective way to counter an incoming missile attacking an aircraft is to launch a defense missile compared with traditional passive defense strategies such as decoy and electronic countermeasures.To address this issue,this paper proposes a three-body cooperative active defense guidance law with overload constraints from the perspective of a small speed ratio.First,a cooperative guidance-oriented model for active defense is established and linearized to provide a foundation for the design of the guidance law.Then,the essential quantity known as Zero-Effort-Miss(ZEM)is analyzed during the engagement process.In order to minimize the influence of inaccurate estimates of remaining flight time in the ZEM,the concept of Zero-Effort-Velocity(ZEV)is introduced.Subsequently,utilizing the sliding mode control method,the guidance law is designed by selecting the ZEM and ZEV as sliding mode surfaces,combined with the fast power reaching law,and its finite-time stability is analyzed using the Lyapunov method.Furthermore,to quantitatively evaluate the performance of the proposed active defense guidance law,the interception rendezvous angle index is introduced.The proposed active defense guidance law considers integrating information from the incoming missile,aircraft,and defense missile with fewer simplifications and assumptions,and ensures that the aircraft is effectively protected with less overload required for the defense missile.Finally,simulation experiments demonstrate the effectiveness and adaptability of the proposed active defense guidance law.
文摘Earth-to-Moon missions with low thrust-to-weight ratios present unique challenges for exoatmospheric guidance,and the existing algorithms are ineffective for the unprecedentedly long burn arcs and high orbital eccentricities.To address these challenges,a Long Burn Arc Powered Explicit Guidance(LBA-PEG)algorithm is developed and compared with the existing algorithms.In the proposed LBA-PEG algorithm,a fully numerical thrust prediction method is developed to accurately predict the highly nonlinear thrust effects over long burn arcs.Moreover,a real-time Newton correction method is proposed to correct the orbit injection point,remedying the position-velocity coupling induced by high orbital eccentricities.The comparison between the proposed algorithm and the existing algorithm shows that the proposed algorithm surpasses the existing ones by significantly enhancing fuel efficiency and improving tolerance to thrust decrease.The proposed LBA-PEG algorithm can adapt to a 65%thrust decrease,which is 12%–22%larger than that of the existing algorithms,and it can still reliably converge and complete the guidance mission even when the length of the burn arc exceeds 90°.The proposed LBA-PEG highlights the algorithm's adaptability for long burn arc missions,especially in critical scenarios such as manned Earth-to-Moon missions.
基金supported by the National Natural Science Foundation of China(No.52175214)。
文摘In this paper,a novel guidance law is proposed which can achieve the desired impact speed and angle simultaneously for unpowered gliding vehicles.A guidance law with only impact angle constraint is used to produce the guidance profile,and its convergence in the varying speed scenario is proved.A relationship between flight states,guidance input and impact speed is established.By applying the fixed-time convergence control theory of error dynamics,an impact speed corrector is built with the above guidance profile,which can implement impact speed correction without affecting the impact angle constraint.Numerical simulations with various impact speed and angle constraints are conducted to demonstrate the performance of the proposed guidance law,and the robustness is also verified by Monte Carlo tests.
基金supported by the National Natural Science Foundation of China,Nos. 81760247, 82171450the Scientific Research Foundation for Doctors of the Affiliated Hospital of Zunyi Medical University,No.(2016)14 (all to HH)。
文摘Current treatments for epilepsy can only manage the symptoms of the condition but cannot alter the initial onset or halt the progression of the disease. Consequently, it is crucial to identify drugs that can target novel cellular and molecular mechanisms and mechanisms of action. Increasing evidence suggests that axon guidance molecules play a role in the structural and functional modifications of neural networks and that the dysregulation of these molecules is associated with epilepsy susceptibility. In this review, we discuss the essential role of axon guidance molecules in neuronal activity in patients with epilepsy as well as the impact of these molecules on synaptic plasticity and brain tissue remodeling. Furthermore, we examine the relationship between axon guidance molecules and neuroinflammation, as well as the structural changes in specific brain regions that contribute to the development of epilepsy. Ample evidence indicates that axon guidance molecules, including semaphorins and ephrins, play a fundamental role in guiding axon growth and the establishment of synaptic connections. Deviations in their expression or function can disrupt neuronal connections, ultimately leading to epileptic seizures. The remodeling of neural networks is a significant characteristic of epilepsy, with axon guidance molecules playing a role in the dynamic reorganization of neural circuits. This, in turn, affects synapse formation and elimination. Dysregulation of these molecules can upset the delicate balance between excitation and inhibition within a neural network, thereby increasing the risk of overexcitation and the development of epilepsy. Inflammatory signals can regulate the expression and function of axon guidance molecules, thus influencing axonal growth, axon orientation, and synaptic plasticity. The dysregulation of neuroinflammation can intensify neuronal dysfunction and contribute to the occurrence of epilepsy. This review delves into the mechanisms associated with the pathogenicity of axon guidance molecules in epilepsy, offering a valuable reference for the exploration of therapeutic targets and presenting a fresh perspective on treatment strategies for this condition.
基金supported by the Lorenz B?hler Fonds,#2/19 (obtained by the Neuroregeneration Group,Ludwig Boltzmann Institute for Traumatology)the City of Vienna project ImmunTissue,MA23#30-11 (obtained by the Department Life Science Engineering,University of Applied Sciences Technikum Wien)。
文摘Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.
基金supported by the National Key Research and Development Program of China(No.2019YFA0706500)。
文摘Flexible lander,composed of multiple nodes connected by flexible material,can reducethe bouncing and overturning during the asteroid landing.To satisfy the complex constraints inthe node cooperation of the flexible landing,an intelligent cooperative guidance method is pro-posed.The method consists of a double-layer cooperative guidance structure,a guidance parameterdetermination approach,and an action priority strategy.The double-layer contains a basic guid-ance used to satisfy the terminal state constraints,and a compensatory guidance used to satisfythe lander's attitude constraint.For the compensatory guidance,the parameters are determinedby multi-agent system,which are trained according to the performance index of flexible landing tra-jectories.The action priority strategy is used to reduce the detrimental effect of parameter inconsis-tency on the node cooperation.The simulation of flexible landing shows that the cooperativeguidance method is effective in improving the landing accuracy while satisfying the constraints.Meanwhile,the method is robust to the disturbance in the navigation and control.
基金supported by the National Natural Science Foundation of China(Grant Number 52472322)the Shanghai Sailing Program(Grant Number 21YF1415800)+1 种基金the Open Project of Key Laboratory of Advanced Public Transportation Science(Grant Number 2023-APTS-05)the Shanghai SASAC Enterprise Innovation and Capability Enhancement Project(Grant Number 2022016,2023020).
文摘Once a train stops in a tunnel section and requires emergency evacuation,the large distance between stations and long walking distances in the underground spaces of suburban railway systems pose potential risks to the evacuation process on tunnel platforms,especially in complex environments.This study utilized Virtual Reality(VR)technology to construct a virtual experimental platform for tunnel evacuation in suburban railway systems,simulating different combinations of smoke and obstacle conditions.By requiring participants to wear VR glasses and walk on an omnidirectional treadmill for moving,as well as complete psychological questionnaires,the study reveals the influences of No Guiding(NG)signs,Wall-Guided(WG)signs,and Central axis Guidance(CG)signs on the movement abilities and psychological behaviors of participants contrastively.The results show that either smoke conditions or obstacle positions affect the mental stress of participants,and the guidance sign has a positive effect on reducing the mental stress.There is an inverse relationship between mental stress and movement abilities.WG and CG signs respectively lead participants to walk closer to walls and along the central axis,which is conducive to reducing the variation in participants’behavior characteristics when circumventing obstacles on the wall side or track side under smoke conditions,respectively.Additionally,CG signs reduce the speed fluctuations of participants before circumventing obstacles,improving the stability of the distance from the wall and speed under smoke conditions,compared to NG and WG signs.These findings contribute to understanding the evacuation psychological-behavioral-movement characteristics of pedestrians on evacuation platforms in suburban railway tunnels and provide a basis for improving the safety design of evacuation guidance signs.
文摘Objective:To investigate the application effects of intelligent guidance systems in optimizing health check-up process management.Methods:A total of 400 examinees who underwent physical examinations at the hospital’s Health Management Center from January to December 2024 were randomly divided into a control group(200 cases)and an observation group(200 cases).The control group used traditional manual guidance methods,while the observation group employed the intelligent guidance system.The study compared two groups in terms of completion time,waiting time for each procedure,check-up efficiency scores,examinee satisfaction,and report issuance time.Results:The overall examination time in the observation group(85.3±12.7 minutes)was significantly shorter than that in the control group(142.6±18.5 minutes)(P<0.01);average waiting time per procedure decreased by 62.4%;check-up efficiency scores(8.9±0.8 points)were significantly higher than those in the control group(5.2±1.1 points)(P<0.01);satisfaction reached 96.5%,significantly higher than the control group’s 78.0%(P<0.01);and report issuance time was advanced by 1.5 days.Conclusion:Intelligent guidance systems can significantly optimize check-up processes,improve work efficiency,and examinee satisfaction,demonstrating significant clinical application value.
基金supported by the National Natural Science Foundation of China(61903099)the Natural Science Foundation of Heilongjiang Province(LH2020F025)+2 种基金the Project of Science and Technology Research Program of Chongqing Education Commission of China(KJZD-K20200470)the Postdoctoral Science Foundation of China(2021M690812)the Postdoctoral Science Fund of Heilongjiang Province(LBH-Z21048).
文摘This paper presents a fixed-time cooperative gui-dance method with impact angle constraints for multiple flight vehicles (MFV) to address the challenges of intercepting large maneuvering targets with difficulty and low precision. A coopera-tive guidance model is proposed, transforming the cooperative interception problem into a consensus problem based on the remaining flight time of the flight vehicles. First, the impact angle constraint is converted into the line of sight (LOS) angle con-straint, and a new fixed-time convergent non-singular terminal sliding surface is introduced, which resolves the singularity issue of the traditional sliding surfaces. With this approach, LOS angle rate and normal overloads can converge in fixed time, ensuring that the upper bound of the system convergence time is not affected by the initial value of the system. Furthermore, the maneuvering movement of the target is considered as a system disturbance, and an extended state observer is employed to estimate and compensate for it in the guidance law. Lastly, by applying consensus theory and distributed communication topology, the remaining flight time of each flight vehicle is syn-chronized to ensure that they intercept the target simulta-neously with different impact angles. Simulation experiments are conducted to validate the effectiveness of the proposed cooper-ative interception and guidance method.
文摘With the continuous increase in the number of university graduates and the intensification of structural contradictions in the job market,employment guidance in local universities faces significant challenges.Based on the theory of digital transformation in education and the application framework of artificial intelligence(AI),this paper explores pathways for AI to enhance the quality of employment guidance in local universities,using employment data of university graduates in Sichuan Province and relevant policy orientations.Through case analysis,survey data,and theoretical research,the study finds that AI can optimize employment guidance processes and improve job-person matching efficiency through intelligent matching,personalized recommendations,and data-driven decision-making mechanisms,thereby facilitating the alignment between talent cultivation in universities and industry demands.The study proposes the construction of an“AI+Employment”ecosystem,the refinement of intelligent evaluation models,and the deepening of university-enterprise collaboration,providing theoretical foundations and practical references for the reform of local university employment guidance systems.
基金supported by the Natural Science Foundation of Shaanxi Province(Nos.2023-YBSF-270,2024SF-ZDCYL-02-08)Fundamental Research Funds for the Central Universities(No.xzy022024033)+2 种基金Horizontal Project of the First Affiliated Hospital of Xi’an Jiaotong University(No.202304174)supported by the Opening Project of Structural Optimization and Application of Functional Molecules Key Laboratory of Sichuan Province(No.2023GNFZ-03)The Key Laboratory for Screening and Diagnosis of Maternal and Child Genetic Disease of Health Commission of Jiangxi Province.
文摘The tumor microenvironment(TME)-activatable probes have proven effective in enhancing the signalto-background ratio(SBR)for precise fluorescence imaging in tumor diagnosis.However,many fluorophores have suboptimal emission spectra and a short Stokes shift,which may lead to overlap with bioautofluorescence,excitation,and emission spectra,limiting their use in intraoperative guidance.Herein,aγ-glutathione(GSH)responsive near-infrared(NIR)BODIPY probe,named“Pro-Dye”was synthesized with a large Stokes shift of 91 nm.The Pro-Dye can be rapidly and specifically activated by high concentrations of GSH both in solution and inside cancer cells,while remaining inactive in normal cells(Human umbilical vein endothelial cells,HUVECs).The Pro-Dye was further encapsulated by 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-(polyethylene glycol)-5000(DSPE-PEG5000)to form Pro-Dye nanoparticles(NPs),making it water-dispersible for in vivo application.In vivo fluorescence imaging demonstrated that Pro-Dye NPs can accumulate at the tumor and exhibit an improved SBR compared to the“alwayson”probe(Dye NPs).Moreover,the tumor can be precisely resected under the real-time guidance of fluorescence imaging of Pro-Dye NPs,showing a well-defined tumor margin.
基金supported by the National Natural Science Foundation of China(62273119).
文摘A cooperative guidance law is proposed in a two-ontwo engagement scenario with large-heading-errors by choosing zero-effort miss distance as a sliding surface,which consists of an attacker,a protector,a defender,and a target,based on fixed-time sliding mode control theory.Based on the nonlinear method of fixed-time sliding mode control,the performance of the cooperative guidance law remains satisfactory even with large-heading-errors scenarios where the linearization-based approaches might be invalid.By virtue of this law,the attacker pursues the target with the assistance of the protector,which can intercept the defender in the engagement scenario.Furthermore,if the attacker is intercepted by the defender,the guidance law of the protector could guarantee that the protector attacks the target.A robust adaptive term is included in the guidance law to deal with the case of the unknown disturbance upper bound of the defender-target team.Finally,the feasibility of the guidance law is verified by nonlinear numerical simulations,and the superiority of it is illustrated by comparing with the linearization guidance law.
基金supported by the National Natural Science Foundation of China(No.91216304)。
文摘This paper proposes a distributed nonsingular cooperative guidance law for multiple flight vehicles with Field-of-View(FOV)constraints.First,a novel time-to-go estimation is developed based on a FOV-constrained Proportional Navigation Guidance(FPNG)law.Then,the FPNG law is augmented with a cooperative guidance term to achieve consensus of time-to-go with predefined-time convergence prior to the impact time.A continuous auxiliary function is introduced in the bias term to avoid the singularity of guidance command.Moreover,the proposed guidance law is extended to the three-dimensional guidance scenarios and the moving target with the help of a predicted interception point.Finally,several numerical simulations are conducted,and the results verify the effectiveness,robustness,and advantages of the proposed cooperative guidance law.
基金supported by the Fundamental Research Grant Scheme(FRGS)(No.FRGS/1/2024/TK04/USM/02/3)funded by the Malaysian Ministry of Higher Education(MOHE).
文摘This paper presents a vision-based navigation framework for micro air vehicles(MAVs)operating in confined warehouse environments.To address the trade-off between low localization accuracy in mapless methods and high computational demands in map-based approaches,the proposed system leverages topology-aware path guidance using monocular vision.Navigation is driven by a digital instruction format(DIF)that encodes both the path index and target junction,enabling autonomous navigation without environmental modifications.The framework comprises a cascaded perception-encoding-control pipeline.For structured paths,foreground pixel density trend analysis with sliding window smoothing for robust junction recognition,while lateral proportionalintegral-derivative(PID)control ensures accurate path tracking.For geometric trajectories,the control logic incorporates L-junction triggers,fixed-angle turns,and spatial yaw correction to accommodate sharp corners and curved segments.ROS-Gazebo simulations validate the method’s effectiveness,achieving up to 94.40%junction recognition accuracy(92.01%on average),trajectory tracking errors below 0.1 m,and terminal localization deviations under 0.2 m.These results validate the method’s accuracy,stability,and suitability for computationally constrained MAV platforms in warehouse automation.
基金supported by the National Natural Science Foundation of China(Nos.61773142,62303136)China Postdoctoral Science Foundation(No.2023M740912)Postdoctoral Fellowship Program of CPSF,China(No.GZC20233447).
文摘In this article,a three-dimensional cooperative guidance problem for highly maneuvering targets is investigated under the assumption of perfect information.Inspired by the coverage strategy,the cooperative guidance problem is decomposed into one-on-one guidance problems against predictive interception points.To expand the coverage area of each missile,these one-on-one guidance problems are formulated as flight path angle tracking problems,and the optimal error dynamics is extended to derive the guidance law analytically.In addition,through the introduction of the coverage probability model,the dynamic coverage strategy is proposed.The predictive interception points are updated online by maximizing the coverage probability,which aims to achieve successful interception despite variations in target acceleration.Furthermore,a switching strategy of the guidance command is designed for collision avoidance.Simulation results demonstrate that the missile group can cooperatively intercept a highly maneuvering target under the proposed guidance law.
