To the editor:Adverse home environments(AHE),characterised by family conflict,parental separation or dysfunctional parenting,are linked to negative mental health outcomes in children and adults.12 AHE disproportionate...To the editor:Adverse home environments(AHE),characterised by family conflict,parental separation or dysfunctional parenting,are linked to negative mental health outcomes in children and adults.12 AHE disproportionately affect children with neurodevelopmental disorders such as attention-deficit/hyperactivity disorder(ADHD),which is characterised by inattention,hyperactivity/impulsivity and functional impairments.3 Apart from core symptoms,including inattention and hyperactivity,disruptive behaviour disorders(DBD),such as oppositional defiant disorder(ODD)and conduct disorder(CD),may be associated with AHE.Conduct problems are risk factors for ODD.And CD has become a main concern for childhood mental health.展开更多
Aiming to address the Unmanned Aerial Vehicle(UAV) formation collision avoidance problem in Three-Dimensional(3-D) low-altitude environments where dense various obstacles exist, a fluid-based path planning framework n...Aiming to address the Unmanned Aerial Vehicle(UAV) formation collision avoidance problem in Three-Dimensional(3-D) low-altitude environments where dense various obstacles exist, a fluid-based path planning framework named the Formation Interfered Fluid Dynamical System(FIFDS) with Moderate Evasive Maneuver Strategy(MEMS) is proposed in this study.First, the UAV formation collision avoidance problem including quantifiable performance indexes is formulated. Second, inspired by the phenomenon of fluids continuously flowing while bypassing objects, the FIFDS for multiple UAVs is presented, which contains a Parallel Streamline Tracking(PST) method for formation keeping and the traditional IFDS for collision avoidance. Third, to rationally balance flight safety and collision avoidance cost, MEMS is proposed to generate moderate evasive maneuvers that match up with collision risks. Comprehensively containing the time and distance safety information, the 3-D dynamic collision regions are modeled for collision prediction. Then, the moderate evasive maneuver principle is refined, which provides criterions of the maneuver amplitude and direction. On this basis, an analytical parameter mapping mechanism is designed to online optimize IFDS parameters. Finally, the performance of the proposed method is validated by comparative simulation results and real flight experiments using fixed-wing UAVs.展开更多
Background Over the last few years,the rapid advancement of technology has led to the development of many approaches to digitalization.In this respect,metaverse provides 3D persistent virtual environments that can be ...Background Over the last few years,the rapid advancement of technology has led to the development of many approaches to digitalization.In this respect,metaverse provides 3D persistent virtual environments that can be used to access digital content,meet virtually,and perform several professional and leisure tasks.Among the numerous technologies supporting the metaverse,immersive Virtual Reality(VR)plays a primary role and offers highly interactive social experiences.Despite growing interest in this area,there are no clear design guidelines for creating environments tailored to the metaverse.Methods This study seeks to advance research in this area by moving from state-of-the-art studies on the design of immersive virtual environments in the context of metaverse and proposing how to integrate cutting-edge technologies within this context.Specifically,the best practices were identified by i)analyzing literature studies focused on human behavior in immersive virtual environments,ii)extracting common features of existing social VR platforms,and iii)conducting interviews with experts in a specific application domain.Specifically,this study considered the creation of a new virtual environment for MetaLibrary,a VR-based social platform aimed at integrating public libraries into metaverse.Several implementation challenges and additional requirements have been identified for the development of virtual environments(VEs).These elements were considered in the selection of specific cutting-edge technologies and their integration into the development process.A user study was also conducted to investigate some design aspects(namely lighting conditions and richness of the scene layout)for which deriving clear indications from the above analysis was not possible because different alternative configurations could be chosen.Results The work reported in this paper seeks to bridge the gap between existing VR platforms and related literature in the field,on the one hand,and requirements regarding immersive virtual environments for the metaverse,on the other hand,by reporting a set of best practices which were used to build a social virtual environment that meets users'expectations and needs.Conclusions Results suggest that carefully designed virtual environments can positively affect user experience and interaction within metaverse.The insights gained from this study offer valuable cues for developing immersive virtual environments for the metaverse to deliver more effective and engaging experiences.展开更多
In the fields of optoelectronics and semiconductors, reliable fixation and handling of brittle materials (glass, wafer, etc.) in high-temperature, vacuum, and vibration environments face particular technical challenge...In the fields of optoelectronics and semiconductors, reliable fixation and handling of brittle materials (glass, wafer, etc.) in high-temperature, vacuum, and vibration environments face particular technical challenges. These challenges include the inability of suction cups in a vacuum, the residue of chemical adhesives, and the easy damage of mechanical clamping. In this paper, fluorine-based bionic adhesive pads (FBAPs) obtained using molding technology to imitate gecko micropillar arrays are presented. FBAPs inhibit the substantial decay of adhesive properties at high temperatures and provide stable and reliable performance in vacuum and vibration environments. The results demonstrated that the decayed force values of the normal and tangential strength of the FBAP were only 9.01% and 5.82% of the planar samples when warmed up to 300℃ from 25℃, respectively. In a vacuum, all FBAPs exhibit less than 20% adhesion attenuation, and in a vibrational environment, they can withstand accelerations of at least 4.27 g. The design of the microstructure arrays enables the realization of efficient and non-destructive separation through mechanical rotation or blowing. It provides a bionic material basis for the fixation of brittle materials on smooth surfaces under complex environments and for transportation automation.展开更多
The authors regret that the scientific names of some species mentioned in the paper were incorrectly presented.The incorrect sci-entific names,their locations in the paper,correct spellings and refer-ences,are listed ...The authors regret that the scientific names of some species mentioned in the paper were incorrectly presented.The incorrect sci-entific names,their locations in the paper,correct spellings and refer-ences,are listed below.展开更多
With the increasing demand for water in hydroponic systems and agricultural irrigation,viral diseases have seriously affected the yield and quality of crops.By removing plant viruses in water environments,virus transm...With the increasing demand for water in hydroponic systems and agricultural irrigation,viral diseases have seriously affected the yield and quality of crops.By removing plant viruses in water environments,virus transmission can be prevented and agricultural production and ecosystems can be protected.But so far,there have been few reports on the removal of plant viruses in water environments.Herein,in this study,easily recyclable biomass-based carbon nanotubes catalysts were synthesized with varying metal activities to activate peroxymonosulfate(PMS).Among them,the magnetic 0.125Fe@NCNTs-1/PMS system showed the best overall removal performance against pepper mild mottle virus,with a 5.9 log_(10)removal within 1 min.Notably,the key reactive species in the 0.125Fe@NCNTs-1/PMS system is^(1)O_(2),which can maintain good removal effect in real water matrices(river water and tap water).Through RNA fragment analyses and label free analysis,it was found that this system could effectively cleave virus particles,destroy viral proteins and expose their genome.The capsid protein of pepper mild mottle virus was effectively decomposed where serine may be the main attacking sites by^(1)O_(2).Long viral RNA fragments(3349 and 1642 nt)were cut into smaller fragments(∼160 nt)and caused their degradation.In summary,this study contributes to controlling the spread of plant viruses in real water environment,which will potentially help protect agricultural production and food safety,and improve the health and sustainability of ecosystems.展开更多
When a fire breaks out in a high-rise building,the occlusion of smoke and obstacles results in dearth of crucial information concerning people in distress,thereby creating a challenge in their detection.Given the rest...When a fire breaks out in a high-rise building,the occlusion of smoke and obstacles results in dearth of crucial information concerning people in distress,thereby creating a challenge in their detection.Given the restricted sensing range of a single unmanned aerial vehicle(UAV)cam-era,enhancing the target recognition rate becomes challenging without target information.To tackle this issue,this paper proposes a multi-agent autonomous collaborative detection method for multi-targets in complex fire environments.The objective is to achieve the fusion of multi-angle visual information,effectively increasing the target’s information dimension,and ultimately address-ing the problem of low target recognition rate caused by the lack of target information.The method steps are as follows:first,the you only look once version5(YOLOv5)is used to detect the target in the image;second,the detected targets are tracked to monitor their movements and trajectories;third,the person re-identification(ReID)model is employed to extract the appearance features of targets;finally,by fusing the visual information from multi-angle cameras,the method achieves multi-agent autonomous collaborative detection.The experimental results show that the method effectively combines the visual information from multi-angle cameras,resulting in improved detec-tion efficiency for people in distress.展开更多
1 Introduction Constrained Reinforcement Learning(CRL),modeled as a Constrained Markov Decision Process(CMDP)[1,2],is commonly used to address applications with security restrictions.Previous works[3]primarily focused...1 Introduction Constrained Reinforcement Learning(CRL),modeled as a Constrained Markov Decision Process(CMDP)[1,2],is commonly used to address applications with security restrictions.Previous works[3]primarily focused on the single-constraint issue,overlooking the more common multi-constraint setting which involves extensive computations and combinatorial optimization of multiple Lagrange multipliers.展开更多
To meet the requirements of electromagnetic(EM)theory and applied physics,this study presents an overview of the state-of-the-art research on obtaining the EM properties of media and points out potential solutions tha...To meet the requirements of electromagnetic(EM)theory and applied physics,this study presents an overview of the state-of-the-art research on obtaining the EM properties of media and points out potential solutions that can break through the bottlenecks of current methods.Firstly,based on the survey of three mainstream approaches for acquiring EM properties of media,we identify the difficulties when implementing them in realistic environments.With a focus on addressing these problems and challenges,we propose a novel paradigm for obtaining the EM properties of multi-type media in realistic environments.Particularly,within this paradigm,we describe the implementation approach of the key technology,namely“multipath extraction using heterogeneous wave propagation data in multi-spectrum cases”.Finally,the latest measurement and simulation results show that the EM properties of multi-type media in realistic environments can be precisely and efficiently acquired by the methodology proposed in this study.展开更多
With the rapid development of drone technology,drones are increasingly used in urban environments,but they also bring many security risks,such as illegal reconnaissance,smuggling,and terrorist attacks.Therefore,it is ...With the rapid development of drone technology,drones are increasingly used in urban environments,but they also bring many security risks,such as illegal reconnaissance,smuggling,and terrorist attacks.Therefore,it is of great significance to study the anti-UAV technology in the urban environment.This paper analyzes the advantages and disadvantages of existing technologies and their applicability in the urban environment from the aspects of UAV detection,identification,and countermeasures,and discusses the future development trend of anti-UAV technology,aiming to provide a reference for urban safety protection.展开更多
Human interaction with natural environments is gaining increasing attention in environmental sciences as research consistently shows that access to green spaces,clean air,and biodiversity plays a crucial role in enhan...Human interaction with natural environments is gaining increasing attention in environmental sciences as research consistently shows that access to green spaces,clean air,and biodiversity plays a crucial role in enhancing physical health,reducing stress,and improving overall well-being.This study conducts a bibliometric and visualization-based analysis of forest therapy research,emphasizing its physiological and psychological benefits.Using the Web of Science database,we identified and analyzed 414 studies from 1998 to 2023.Through CiteSpace and VOSviewer,we mapped these documents to examine research trends,publication networks,leading scholars and institutions,key journals,and thematic evolution.Findings indicate that forest therapy research is predominantly concentrated in East Asia,North America,Australia,and Europe,with strong collaborative networks among authors and institutions.The concentration of publications,research evolution,and keyword trends reflect the development of forest therapy research.The analysis further identifies sixteen research clusters and discusses two research themes:physiological and psychological effects.By analyzing how the natural environment contributes to human well-being,we provide a comprehensive and visually structured understanding of forest therapy as an intersection of environmental science,public health and well-being,and ecosystem conservation.Our findings offer a new perspective for future interdisciplinary research,emphasizing the need for well-designed clinical trials to substantiate forest therapy’s diverse health effects and its role in promoting sustainable interactions between human societies and natural environments.展开更多
Background:Cold temperatures cause blood vessels to constrict,shallow breathing,and slight thickening of the blood.Working in extremely cold environments can have negative effects on health,yet there are currently no ...Background:Cold temperatures cause blood vessels to constrict,shallow breathing,and slight thickening of the blood.Working in extremely cold environments can have negative effects on health,yet there are currently no effective biomarkers to monitor these health conditions.Proteins are important intermediate phenotypes that can provide a theoretical basis for understanding disease pathophysiology.Proteins in the circulatory system reflect the physiological status of individuals,and plasma proteins have significant potential as biomarkers for various health conditions.Methods:In this study,we employed the Mendelian randomization(MR)method to analyze the effects of freezing temperatures on over 2900 plasma proteins.Subsequently,the selected plasma proteins were subjected to causal analysis in relation to 55 diseases,including respiratory disorders,cardiovascular diseases,various cancers,and oral diseases.The aim was to identify proteins that could serve as biomarkers for health status.Results:Our results indicate that cold environments may affect the concentrations of 78 plasma proteins.Further MR analysis revealed that nine of these plasma proteins are associated with the risk of respiratory disorders,cardiovascular diseases,various cancers,and oral diseases.Conclusion:These proteins show promise as biomarkers for monitoring the hazards and risks faced by individuals working in cold environments.These findings provide valuable insights into the biological mechanisms underlying occupational hazards.展开更多
Semi-supervised learning(SSL)aims to improve performance by exploiting unlabeled data when labels are scarce.Conventional SSL studies typically assume close environments where important factors(e.g.,label,feature,dist...Semi-supervised learning(SSL)aims to improve performance by exploiting unlabeled data when labels are scarce.Conventional SSL studies typically assume close environments where important factors(e.g.,label,feature,distribution)between labeled and unlabeled data are consistent.However,more practical tasks involve open environments where important factors between labeled and unlabeled data are inconsistent.It has been reported that exploiting inconsistent unlabeled data causes severe performance degradation,even worse than the simple supervised learning baseline.Manually verifying the quality of unlabeled data is not desirable,therefore,it is important to study robust SSL with inconsistent unlabeled data in open environments.This paper briefly introduces some advances in this line of research,focusing on techniques concerning label,feature,and data distribution inconsistency in SSL,and presents the evaluation benchmarks.Open research problems are also discussed for reference purposes.展开更多
Urban combat environments pose complex and variable challenges for UAV path planning due to multidimensional factors,such as static and dynamic obstructions as well as risks of exposure to enemy detection,which threat...Urban combat environments pose complex and variable challenges for UAV path planning due to multidimensional factors,such as static and dynamic obstructions as well as risks of exposure to enemy detection,which threaten flight safety and mission success.Traditional path planning methods typically depend solely on the distribution of static obstacles to generate collision-free paths,without accounting for constraints imposed by enemy detection and strike capabilities.Such a simplified approach can yield safety-compromising routes in highly complex urban airspace.To address these limitations,this study proposes a multi-parameter path planning method based on reachable airspace visibility graphs,which integrates UAV performance constraints,environmental limitations,and exposure risks.An innovative heuristic algorithm is developed to balance operational safety and efficiency by both exposure risks and path length.In the case study set in a typical mixed-use urban area,analysis of airspace visibility graphs reveals significant variations in exposure risk at different regions and altitudes due to building encroachments.Path optimization results indicate that the method can effectively generate covert and efficient flight paths by dynamically adjusting the exposure index,which represents the likelihood of enemy detection,and the path length,which corresponds to mission execution time.展开更多
Essentially clearing the structure-activity relationship between iron carbide catalysts involving multiple active centers to understand the reaction mechanism of CO hydrogenation conversion process is still a great ch...Essentially clearing the structure-activity relationship between iron carbide catalysts involving multiple active centers to understand the reaction mechanism of CO hydrogenation conversion process is still a great challenge.Here,two main micro-environment factors,namely electronic properties and geometrical effects were found to have an integrated effect on the mechanism of CO hydrogenation conversion,involving active sites on multiple crystal phases.The Bader charge of the surface Fe atoms on the active sites had a guiding effect on the CO activation pathway,while the spatial configuration of the active sites greatly affected the energy barriers of CO activation.Although the defective surfaces were more conducive to CO activation,the defective sites were not the only sites to dissociate CO,as CO always tended to dissociate in a wider area.This synergistic effect of the micro-environment also occurred during the CO conversion process.Surface C atoms on relatively flat configurations were more likely to form methane,while the electronic properties of the active sites could effectively describe the C-C coupling process,as well as distinguish the coupling mechanisms.展开更多
This research investigates the application of digital images in military contexts by utilizing analytical equations to augment human visual capabilities.A comparable filter is used to improve the visual quality of the...This research investigates the application of digital images in military contexts by utilizing analytical equations to augment human visual capabilities.A comparable filter is used to improve the visual quality of the photographs by reducing truncations in the existing images.Furthermore,the collected images undergo processing using histogram gradients and a flexible threshold value that may be adjusted in specific situations.Thus,it is possible to reduce the occurrence of overlapping circumstances in collective picture characteristics by substituting grey-scale photos with colorized factors.The proposed method offers additional robust feature representations by imposing a limiting factor to reduce overall scattering values.This is achieved by visualizing a graphical function.Moreover,to derive valuable insights from a series of photos,both the separation and in-version processes are conducted.This involves analyzing comparison results across four different scenarios.The results of the comparative analysis show that the proposed method effectively reduces the difficulties associated with time and space to 1 s and 3%,respectively.In contrast,the existing strategy exhibits higher complexities of 3 s and 9.1%,respectively.展开更多
With the increasing emphasis on personal information protection,encryption through security protocols has emerged as a critical requirement in data transmission and reception processes.Nevertheless,IoT ecosystems comp...With the increasing emphasis on personal information protection,encryption through security protocols has emerged as a critical requirement in data transmission and reception processes.Nevertheless,IoT ecosystems comprise heterogeneous networks where outdated systems coexist with the latest devices,spanning a range of devices from non-encrypted ones to fully encrypted ones.Given the limited visibility into payloads in this context,this study investigates AI-based attack detection methods that leverage encrypted traffic metadata,eliminating the need for decryption and minimizing system performance degradation—especially in light of these heterogeneous devices.Using the UNSW-NB15 and CICIoT-2023 dataset,encrypted and unencrypted traffic were categorized according to security protocol,and AI-based intrusion detection experiments were conducted for each traffic type based on metadata.To mitigate the problem of class imbalance,eight different data sampling techniques were applied.The effectiveness of these sampling techniques was then comparatively analyzed using two ensemble models and three Deep Learning(DL)models from various perspectives.The experimental results confirmed that metadata-based attack detection is feasible using only encrypted traffic.In the UNSW-NB15 dataset,the f1-score of encrypted traffic was approximately 0.98,which is 4.3%higher than that of unencrypted traffic(approximately 0.94).In addition,analysis of the encrypted traffic in the CICIoT-2023 dataset using the same method showed a significantly lower f1-score of roughly 0.43,indicating that the quality of the dataset and the preprocessing approach have a substantial impact on detection performance.Furthermore,when data sampling techniques were applied to encrypted traffic,the recall in the UNSWNB15(Encrypted)dataset improved by up to 23.0%,and in the CICIoT-2023(Encrypted)dataset by 20.26%,showing a similar level of improvement.Notably,in CICIoT-2023,f1-score and Receiver Operation Characteristic-Area Under the Curve(ROC-AUC)increased by 59.0%and 55.94%,respectively.These results suggest that data sampling can have a positive effect even in encrypted environments.However,the extent of the improvement may vary depending on data quality,model architecture,and sampling strategy.展开更多
With the rapid development of the marine economy,marine microbiologically influenced corrosion(MIC)has garnered increasing attention.However,most studies have not analyzed the MIC process over continuous and extended ...With the rapid development of the marine economy,marine microbiologically influenced corrosion(MIC)has garnered increasing attention.However,most studies have not analyzed the MIC process over continuous and extended periods,failing to provide a comprehensive understanding of MIC mechanisms at different stages.In this study,the corrosion behavior of EH36 steel caused by Halomonas titanicae in an aerobic enriched seawater over a 30-d incubation period was investigated driven by big data.The results revealed that the corrosion by H.titanicae against EH36 steel evolved dynamically over time.During the initial stages,the aerobic respiration of H.titanicae consumed significant amounts of oxygen,which suppressed the cathodic oxygen reduction process,thereby inhibiting corrosion compared to the abiotic conditions.As time progressed,the accumulation of corrosion products slowed the abiotic corrosion,while the biotic corrosion accelerated due to a shift from aerobic to anaerobic respiration by H.titanicae,utilizing Fe0 and nitrate as electron donors and acceptors,respectively.The big data results are consistent with the weight loss and electrochemical data,demonstrating the reliability of using big data monitoring techniques to characterize microbial corrosion processes.展开更多
Meteorological detection environments hold a fundamental and pioneering position in the development of meteorological undertakings,serving as the scientific support for accurately conducting weather forecast,professio...Meteorological detection environments hold a fundamental and pioneering position in the development of meteorological undertakings,serving as the scientific support for accurately conducting weather forecast,professional meteorological services,and disaster prevention and mitigation decision.The safety and stability of meteorological detection environments are of vital importance,and any behavior that damages or affects the detection environments is not allowed.In this paper,the factors influencing meteorological detection environments in the new era were explored,and measures to protect meteorological detection environments were proposed,such as strictly implementing the protection system of meteorological detection environments,lawfully investigating and punishing destructive behaviors,intensifying the publicity of the protection law,and enhancing public awareness.展开更多
This study addresses the issue of spray icing on the air intake grilles of ship power systems in cold maritime environments.Through numerical simulation methods,the influence of environmental parameters on icing chara...This study addresses the issue of spray icing on the air intake grilles of ship power systems in cold maritime environments.Through numerical simulation methods,the influence of environmental parameters on icing characteristics is revealed,and an energy-efficient zoned electric heating anti-icing strategy is proposed.A threedimensional grille model is constructed to systematically analyze the effects of environmental temperature(from−20℃to−4℃),droplet diameter(from 50μm to 500μm),and liquid water content(from 0.5 g/m³to 8 g/m³)on icing rates and blockage of the flow channel.The results indicate that low temperature and high liquid water content significantly exacerbate icing.Under the condition of an environmental temperature of−20℃,droplet diameter of 500μm,and liquid water content of 8 g/m³,the flow channel blockage ratio reaches 30.95%within 10 min.Additionally,as droplet diameter increases,the droplet impingement and icing regions become more concentrated toward the leading edge of blades.To mitigate grille icing in cold environments,an electric heating film configuration is employed for thermal protection.Optimization of the heating strategy reveals that the zoned heating approach,compared to the initial uniform heating scheme,effectively homogenizes surface temperature distribution while reducing total power consumption by 37.47%.This study validates the engineering applicability of the zoned electric heating anti/de-icing strategy,providing theoretical and technical support for the design of anti-icing systems in ship power systems operating in cold maritime regions.展开更多
基金supported by National Natural Science Foundation Youth Project (81901386)the Fundamental Research Funds for the Central Universities (YG2025ZD07)+5 种基金the National Science and Technology Innovation 2030 Major Project of China (2021ZD0203900)National Natural Science Foundation of China (NSFC) grant (82422029)the Science and Technology Commission of Shanghai Municipality (24Y22800200, 22QA1407900)NSFC grant (82271530)Innovation teams of high-level universities in Shanghaithe Scientific Research and Innovation Team of Liaoning Normal University (24TD004).
文摘To the editor:Adverse home environments(AHE),characterised by family conflict,parental separation or dysfunctional parenting,are linked to negative mental health outcomes in children and adults.12 AHE disproportionately affect children with neurodevelopmental disorders such as attention-deficit/hyperactivity disorder(ADHD),which is characterised by inattention,hyperactivity/impulsivity and functional impairments.3 Apart from core symptoms,including inattention and hyperactivity,disruptive behaviour disorders(DBD),such as oppositional defiant disorder(ODD)and conduct disorder(CD),may be associated with AHE.Conduct problems are risk factors for ODD.And CD has become a main concern for childhood mental health.
基金supported in part by the National Natural Science Foundations of China(Nos.61175084,61673042 and 62203046)the China Postdoctoral Science Foundation(No.2022M713006).
文摘Aiming to address the Unmanned Aerial Vehicle(UAV) formation collision avoidance problem in Three-Dimensional(3-D) low-altitude environments where dense various obstacles exist, a fluid-based path planning framework named the Formation Interfered Fluid Dynamical System(FIFDS) with Moderate Evasive Maneuver Strategy(MEMS) is proposed in this study.First, the UAV formation collision avoidance problem including quantifiable performance indexes is formulated. Second, inspired by the phenomenon of fluids continuously flowing while bypassing objects, the FIFDS for multiple UAVs is presented, which contains a Parallel Streamline Tracking(PST) method for formation keeping and the traditional IFDS for collision avoidance. Third, to rationally balance flight safety and collision avoidance cost, MEMS is proposed to generate moderate evasive maneuvers that match up with collision risks. Comprehensively containing the time and distance safety information, the 3-D dynamic collision regions are modeled for collision prediction. Then, the moderate evasive maneuver principle is refined, which provides criterions of the maneuver amplitude and direction. On this basis, an analytical parameter mapping mechanism is designed to online optimize IFDS parameters. Finally, the performance of the proposed method is validated by comparative simulation results and real flight experiments using fixed-wing UAVs.
基金Supported by Fondazione TIM in the context of the “Facciamola Facile” initiativeby Programma Operativo Nazionale (PON)“Ricerca e Innovazione” 2014-2020-DM 1062/2021 funds
文摘Background Over the last few years,the rapid advancement of technology has led to the development of many approaches to digitalization.In this respect,metaverse provides 3D persistent virtual environments that can be used to access digital content,meet virtually,and perform several professional and leisure tasks.Among the numerous technologies supporting the metaverse,immersive Virtual Reality(VR)plays a primary role and offers highly interactive social experiences.Despite growing interest in this area,there are no clear design guidelines for creating environments tailored to the metaverse.Methods This study seeks to advance research in this area by moving from state-of-the-art studies on the design of immersive virtual environments in the context of metaverse and proposing how to integrate cutting-edge technologies within this context.Specifically,the best practices were identified by i)analyzing literature studies focused on human behavior in immersive virtual environments,ii)extracting common features of existing social VR platforms,and iii)conducting interviews with experts in a specific application domain.Specifically,this study considered the creation of a new virtual environment for MetaLibrary,a VR-based social platform aimed at integrating public libraries into metaverse.Several implementation challenges and additional requirements have been identified for the development of virtual environments(VEs).These elements were considered in the selection of specific cutting-edge technologies and their integration into the development process.A user study was also conducted to investigate some design aspects(namely lighting conditions and richness of the scene layout)for which deriving clear indications from the above analysis was not possible because different alternative configurations could be chosen.Results The work reported in this paper seeks to bridge the gap between existing VR platforms and related literature in the field,on the one hand,and requirements regarding immersive virtual environments for the metaverse,on the other hand,by reporting a set of best practices which were used to build a social virtual environment that meets users'expectations and needs.Conclusions Results suggest that carefully designed virtual environments can positively affect user experience and interaction within metaverse.The insights gained from this study offer valuable cues for developing immersive virtual environments for the metaverse to deliver more effective and engaging experiences.
基金supported by the National Natural Science Foundation of China(No.52075249)the Tianyuan Laboratory Fund(No.24-JSKY-ZZKT-14).
文摘In the fields of optoelectronics and semiconductors, reliable fixation and handling of brittle materials (glass, wafer, etc.) in high-temperature, vacuum, and vibration environments face particular technical challenges. These challenges include the inability of suction cups in a vacuum, the residue of chemical adhesives, and the easy damage of mechanical clamping. In this paper, fluorine-based bionic adhesive pads (FBAPs) obtained using molding technology to imitate gecko micropillar arrays are presented. FBAPs inhibit the substantial decay of adhesive properties at high temperatures and provide stable and reliable performance in vacuum and vibration environments. The results demonstrated that the decayed force values of the normal and tangential strength of the FBAP were only 9.01% and 5.82% of the planar samples when warmed up to 300℃ from 25℃, respectively. In a vacuum, all FBAPs exhibit less than 20% adhesion attenuation, and in a vibrational environment, they can withstand accelerations of at least 4.27 g. The design of the microstructure arrays enables the realization of efficient and non-destructive separation through mechanical rotation or blowing. It provides a bionic material basis for the fixation of brittle materials on smooth surfaces under complex environments and for transportation automation.
文摘The authors regret that the scientific names of some species mentioned in the paper were incorrectly presented.The incorrect sci-entific names,their locations in the paper,correct spellings and refer-ences,are listed below.
基金supported by the National Natural Science Foundation of China(No.52170060)the Major Science and Technology Project from the Ministry of Water Resources(No.SKS-2022069)the Science and Technology Program of Inner Mongolia Autonomous Region(No.2021GG0089).
文摘With the increasing demand for water in hydroponic systems and agricultural irrigation,viral diseases have seriously affected the yield and quality of crops.By removing plant viruses in water environments,virus transmission can be prevented and agricultural production and ecosystems can be protected.But so far,there have been few reports on the removal of plant viruses in water environments.Herein,in this study,easily recyclable biomass-based carbon nanotubes catalysts were synthesized with varying metal activities to activate peroxymonosulfate(PMS).Among them,the magnetic 0.125Fe@NCNTs-1/PMS system showed the best overall removal performance against pepper mild mottle virus,with a 5.9 log_(10)removal within 1 min.Notably,the key reactive species in the 0.125Fe@NCNTs-1/PMS system is^(1)O_(2),which can maintain good removal effect in real water matrices(river water and tap water).Through RNA fragment analyses and label free analysis,it was found that this system could effectively cleave virus particles,destroy viral proteins and expose their genome.The capsid protein of pepper mild mottle virus was effectively decomposed where serine may be the main attacking sites by^(1)O_(2).Long viral RNA fragments(3349 and 1642 nt)were cut into smaller fragments(∼160 nt)and caused their degradation.In summary,this study contributes to controlling the spread of plant viruses in real water environment,which will potentially help protect agricultural production and food safety,and improve the health and sustainability of ecosystems.
文摘When a fire breaks out in a high-rise building,the occlusion of smoke and obstacles results in dearth of crucial information concerning people in distress,thereby creating a challenge in their detection.Given the restricted sensing range of a single unmanned aerial vehicle(UAV)cam-era,enhancing the target recognition rate becomes challenging without target information.To tackle this issue,this paper proposes a multi-agent autonomous collaborative detection method for multi-targets in complex fire environments.The objective is to achieve the fusion of multi-angle visual information,effectively increasing the target’s information dimension,and ultimately address-ing the problem of low target recognition rate caused by the lack of target information.The method steps are as follows:first,the you only look once version5(YOLOv5)is used to detect the target in the image;second,the detected targets are tracked to monitor their movements and trajectories;third,the person re-identification(ReID)model is employed to extract the appearance features of targets;finally,by fusing the visual information from multi-angle cameras,the method achieves multi-agent autonomous collaborative detection.The experimental results show that the method effectively combines the visual information from multi-angle cameras,resulting in improved detec-tion efficiency for people in distress.
基金supported by the Fundamental Research Funds for the Central Universities(No.2023JBZX011)the Aeronautical Science Foundation of China(No.202300010M5001).
文摘1 Introduction Constrained Reinforcement Learning(CRL),modeled as a Constrained Markov Decision Process(CMDP)[1,2],is commonly used to address applications with security restrictions.Previous works[3]primarily focused on the single-constraint issue,overlooking the more common multi-constraint setting which involves extensive computations and combinatorial optimization of multiple Lagrange multipliers.
基金supported by the Beijing Natural Science Foundation(No.L212029)the National Natural Science Foundation of China(No.62271043).
文摘To meet the requirements of electromagnetic(EM)theory and applied physics,this study presents an overview of the state-of-the-art research on obtaining the EM properties of media and points out potential solutions that can break through the bottlenecks of current methods.Firstly,based on the survey of three mainstream approaches for acquiring EM properties of media,we identify the difficulties when implementing them in realistic environments.With a focus on addressing these problems and challenges,we propose a novel paradigm for obtaining the EM properties of multi-type media in realistic environments.Particularly,within this paradigm,we describe the implementation approach of the key technology,namely“multipath extraction using heterogeneous wave propagation data in multi-spectrum cases”.Finally,the latest measurement and simulation results show that the EM properties of multi-type media in realistic environments can be precisely and efficiently acquired by the methodology proposed in this study.
文摘With the rapid development of drone technology,drones are increasingly used in urban environments,but they also bring many security risks,such as illegal reconnaissance,smuggling,and terrorist attacks.Therefore,it is of great significance to study the anti-UAV technology in the urban environment.This paper analyzes the advantages and disadvantages of existing technologies and their applicability in the urban environment from the aspects of UAV detection,identification,and countermeasures,and discusses the future development trend of anti-UAV technology,aiming to provide a reference for urban safety protection.
文摘Human interaction with natural environments is gaining increasing attention in environmental sciences as research consistently shows that access to green spaces,clean air,and biodiversity plays a crucial role in enhancing physical health,reducing stress,and improving overall well-being.This study conducts a bibliometric and visualization-based analysis of forest therapy research,emphasizing its physiological and psychological benefits.Using the Web of Science database,we identified and analyzed 414 studies from 1998 to 2023.Through CiteSpace and VOSviewer,we mapped these documents to examine research trends,publication networks,leading scholars and institutions,key journals,and thematic evolution.Findings indicate that forest therapy research is predominantly concentrated in East Asia,North America,Australia,and Europe,with strong collaborative networks among authors and institutions.The concentration of publications,research evolution,and keyword trends reflect the development of forest therapy research.The analysis further identifies sixteen research clusters and discusses two research themes:physiological and psychological effects.By analyzing how the natural environment contributes to human well-being,we provide a comprehensive and visually structured understanding of forest therapy as an intersection of environmental science,public health and well-being,and ecosystem conservation.Our findings offer a new perspective for future interdisciplinary research,emphasizing the need for well-designed clinical trials to substantiate forest therapy’s diverse health effects and its role in promoting sustainable interactions between human societies and natural environments.
基金funded by the Health Commission of Heilongjiang Province(Project Number:20230808010517).
文摘Background:Cold temperatures cause blood vessels to constrict,shallow breathing,and slight thickening of the blood.Working in extremely cold environments can have negative effects on health,yet there are currently no effective biomarkers to monitor these health conditions.Proteins are important intermediate phenotypes that can provide a theoretical basis for understanding disease pathophysiology.Proteins in the circulatory system reflect the physiological status of individuals,and plasma proteins have significant potential as biomarkers for various health conditions.Methods:In this study,we employed the Mendelian randomization(MR)method to analyze the effects of freezing temperatures on over 2900 plasma proteins.Subsequently,the selected plasma proteins were subjected to causal analysis in relation to 55 diseases,including respiratory disorders,cardiovascular diseases,various cancers,and oral diseases.The aim was to identify proteins that could serve as biomarkers for health status.Results:Our results indicate that cold environments may affect the concentrations of 78 plasma proteins.Further MR analysis revealed that nine of these plasma proteins are associated with the risk of respiratory disorders,cardiovascular diseases,various cancers,and oral diseases.Conclusion:These proteins show promise as biomarkers for monitoring the hazards and risks faced by individuals working in cold environments.These findings provide valuable insights into the biological mechanisms underlying occupational hazards.
基金supported by the Key Program of Jiangsu Science Foundation(BK20243012)the National Natural Science Foundation of China(NSFC)(Grant Nos.62306133,62176118).
文摘Semi-supervised learning(SSL)aims to improve performance by exploiting unlabeled data when labels are scarce.Conventional SSL studies typically assume close environments where important factors(e.g.,label,feature,distribution)between labeled and unlabeled data are consistent.However,more practical tasks involve open environments where important factors between labeled and unlabeled data are inconsistent.It has been reported that exploiting inconsistent unlabeled data causes severe performance degradation,even worse than the simple supervised learning baseline.Manually verifying the quality of unlabeled data is not desirable,therefore,it is important to study robust SSL with inconsistent unlabeled data in open environments.This paper briefly introduces some advances in this line of research,focusing on techniques concerning label,feature,and data distribution inconsistency in SSL,and presents the evaluation benchmarks.Open research problems are also discussed for reference purposes.
基金supported by the Ministry of Industry and Information Technology(No.23100002022102001)。
文摘Urban combat environments pose complex and variable challenges for UAV path planning due to multidimensional factors,such as static and dynamic obstructions as well as risks of exposure to enemy detection,which threaten flight safety and mission success.Traditional path planning methods typically depend solely on the distribution of static obstacles to generate collision-free paths,without accounting for constraints imposed by enemy detection and strike capabilities.Such a simplified approach can yield safety-compromising routes in highly complex urban airspace.To address these limitations,this study proposes a multi-parameter path planning method based on reachable airspace visibility graphs,which integrates UAV performance constraints,environmental limitations,and exposure risks.An innovative heuristic algorithm is developed to balance operational safety and efficiency by both exposure risks and path length.In the case study set in a typical mixed-use urban area,analysis of airspace visibility graphs reveals significant variations in exposure risk at different regions and altitudes due to building encroachments.Path optimization results indicate that the method can effectively generate covert and efficient flight paths by dynamically adjusting the exposure index,which represents the likelihood of enemy detection,and the path length,which corresponds to mission execution time.
基金supported by the Research Fund for National Key Research and Development Program of China(2022YFA1503804,2021YFA1501403)the Natural Science Foundation of China(22208094,21922803,92034301,22008066 and 21776077)+2 种基金the China Postdoctoral Science Foundation(BX20190116)the Innovation Program of Shanghai Municipal Education Commission(17ZR1407300)the Program of Shanghai Academic/Technology Research Leader(21XD1421000).
文摘Essentially clearing the structure-activity relationship between iron carbide catalysts involving multiple active centers to understand the reaction mechanism of CO hydrogenation conversion process is still a great challenge.Here,two main micro-environment factors,namely electronic properties and geometrical effects were found to have an integrated effect on the mechanism of CO hydrogenation conversion,involving active sites on multiple crystal phases.The Bader charge of the surface Fe atoms on the active sites had a guiding effect on the CO activation pathway,while the spatial configuration of the active sites greatly affected the energy barriers of CO activation.Although the defective surfaces were more conducive to CO activation,the defective sites were not the only sites to dissociate CO,as CO always tended to dissociate in a wider area.This synergistic effect of the micro-environment also occurred during the CO conversion process.Surface C atoms on relatively flat configurations were more likely to form methane,while the electronic properties of the active sites could effectively describe the C-C coupling process,as well as distinguish the coupling mechanisms.
基金financially supported by Ongoing Research Funding Program(ORF-2025-846),King Saud University,Riyadh,Saudi Arabia.
文摘This research investigates the application of digital images in military contexts by utilizing analytical equations to augment human visual capabilities.A comparable filter is used to improve the visual quality of the photographs by reducing truncations in the existing images.Furthermore,the collected images undergo processing using histogram gradients and a flexible threshold value that may be adjusted in specific situations.Thus,it is possible to reduce the occurrence of overlapping circumstances in collective picture characteristics by substituting grey-scale photos with colorized factors.The proposed method offers additional robust feature representations by imposing a limiting factor to reduce overall scattering values.This is achieved by visualizing a graphical function.Moreover,to derive valuable insights from a series of photos,both the separation and in-version processes are conducted.This involves analyzing comparison results across four different scenarios.The results of the comparative analysis show that the proposed method effectively reduces the difficulties associated with time and space to 1 s and 3%,respectively.In contrast,the existing strategy exhibits higher complexities of 3 s and 9.1%,respectively.
基金supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.RS-2023-00235509Development of security monitoring technology based network behavior against encrypted cyber threats in ICT convergence environment).
文摘With the increasing emphasis on personal information protection,encryption through security protocols has emerged as a critical requirement in data transmission and reception processes.Nevertheless,IoT ecosystems comprise heterogeneous networks where outdated systems coexist with the latest devices,spanning a range of devices from non-encrypted ones to fully encrypted ones.Given the limited visibility into payloads in this context,this study investigates AI-based attack detection methods that leverage encrypted traffic metadata,eliminating the need for decryption and minimizing system performance degradation—especially in light of these heterogeneous devices.Using the UNSW-NB15 and CICIoT-2023 dataset,encrypted and unencrypted traffic were categorized according to security protocol,and AI-based intrusion detection experiments were conducted for each traffic type based on metadata.To mitigate the problem of class imbalance,eight different data sampling techniques were applied.The effectiveness of these sampling techniques was then comparatively analyzed using two ensemble models and three Deep Learning(DL)models from various perspectives.The experimental results confirmed that metadata-based attack detection is feasible using only encrypted traffic.In the UNSW-NB15 dataset,the f1-score of encrypted traffic was approximately 0.98,which is 4.3%higher than that of unencrypted traffic(approximately 0.94).In addition,analysis of the encrypted traffic in the CICIoT-2023 dataset using the same method showed a significantly lower f1-score of roughly 0.43,indicating that the quality of the dataset and the preprocessing approach have a substantial impact on detection performance.Furthermore,when data sampling techniques were applied to encrypted traffic,the recall in the UNSWNB15(Encrypted)dataset improved by up to 23.0%,and in the CICIoT-2023(Encrypted)dataset by 20.26%,showing a similar level of improvement.Notably,in CICIoT-2023,f1-score and Receiver Operation Characteristic-Area Under the Curve(ROC-AUC)increased by 59.0%and 55.94%,respectively.These results suggest that data sampling can have a positive effect even in encrypted environments.However,the extent of the improvement may vary depending on data quality,model architecture,and sampling strategy.
基金financially supported by the National Natural Science Foundation of China(Nos.U2106206,52471079,42276212,and 42176043)the Natural Science Foundation of Shandong Province(ZR2024ME047)+1 种基金the National Materials Corrosion and Protection Data Center(No.2023DATAFU20-01)The authors wish to acknowledge Sen Wang,Haiyan Yu,Xiaomin Zhao from State Key Laboratory of Microbial Technology,Shandong University for the assistance in the SEM analysis。
文摘With the rapid development of the marine economy,marine microbiologically influenced corrosion(MIC)has garnered increasing attention.However,most studies have not analyzed the MIC process over continuous and extended periods,failing to provide a comprehensive understanding of MIC mechanisms at different stages.In this study,the corrosion behavior of EH36 steel caused by Halomonas titanicae in an aerobic enriched seawater over a 30-d incubation period was investigated driven by big data.The results revealed that the corrosion by H.titanicae against EH36 steel evolved dynamically over time.During the initial stages,the aerobic respiration of H.titanicae consumed significant amounts of oxygen,which suppressed the cathodic oxygen reduction process,thereby inhibiting corrosion compared to the abiotic conditions.As time progressed,the accumulation of corrosion products slowed the abiotic corrosion,while the biotic corrosion accelerated due to a shift from aerobic to anaerobic respiration by H.titanicae,utilizing Fe0 and nitrate as electron donors and acceptors,respectively.The big data results are consistent with the weight loss and electrochemical data,demonstrating the reliability of using big data monitoring techniques to characterize microbial corrosion processes.
文摘Meteorological detection environments hold a fundamental and pioneering position in the development of meteorological undertakings,serving as the scientific support for accurately conducting weather forecast,professional meteorological services,and disaster prevention and mitigation decision.The safety and stability of meteorological detection environments are of vital importance,and any behavior that damages or affects the detection environments is not allowed.In this paper,the factors influencing meteorological detection environments in the new era were explored,and measures to protect meteorological detection environments were proposed,such as strictly implementing the protection system of meteorological detection environments,lawfully investigating and punishing destructive behaviors,intensifying the publicity of the protection law,and enhancing public awareness.
基金supported in part by the Ship Preliminary Research Project (No.3020401020102)。
文摘This study addresses the issue of spray icing on the air intake grilles of ship power systems in cold maritime environments.Through numerical simulation methods,the influence of environmental parameters on icing characteristics is revealed,and an energy-efficient zoned electric heating anti-icing strategy is proposed.A threedimensional grille model is constructed to systematically analyze the effects of environmental temperature(from−20℃to−4℃),droplet diameter(from 50μm to 500μm),and liquid water content(from 0.5 g/m³to 8 g/m³)on icing rates and blockage of the flow channel.The results indicate that low temperature and high liquid water content significantly exacerbate icing.Under the condition of an environmental temperature of−20℃,droplet diameter of 500μm,and liquid water content of 8 g/m³,the flow channel blockage ratio reaches 30.95%within 10 min.Additionally,as droplet diameter increases,the droplet impingement and icing regions become more concentrated toward the leading edge of blades.To mitigate grille icing in cold environments,an electric heating film configuration is employed for thermal protection.Optimization of the heating strategy reveals that the zoned heating approach,compared to the initial uniform heating scheme,effectively homogenizes surface temperature distribution while reducing total power consumption by 37.47%.This study validates the engineering applicability of the zoned electric heating anti/de-icing strategy,providing theoretical and technical support for the design of anti-icing systems in ship power systems operating in cold maritime regions.
