To fit the complicated geographic conditions of the Three Gorges Reservoir area, a two-level multi-objective monitoring system was developed to monitor the atmosphere of the area. Statistical analysis of environmental...To fit the complicated geographic conditions of the Three Gorges Reservoir area, a two-level multi-objective monitoring system was developed to monitor the atmosphere of the area. Statistical analysis of environmental monitoring data and the macro control principle were employed to configure the upper layer. The lower layer was designed by the application of the thumb rule to a local terrain and specific point sources of pollution therein. The optimized two-level system comprises an upper layer of 16 monitoring stations distributed at places of diverse geographical, ecological, economical and social characteristics, and a lower layer of ]6 sub-machines at each monitoring station of the upper layer. This optimal outcome fits the complicated conditions of the Three Gorges Reservoir area, substantially cuts down the installation cost and the operation cost, and provides accurate monitoring data of atmosphere over the entire area with a high resolution.展开更多
The security performance of cloud services is a key factor influencing users’selection of Cloud Service Providers(CSPs).Continuous monitoring of the security status of cloud services is critical.However,existing rese...The security performance of cloud services is a key factor influencing users’selection of Cloud Service Providers(CSPs).Continuous monitoring of the security status of cloud services is critical.However,existing research lacks a practical framework for such ongoing monitoring.To address this gap,this paper proposes the first NonCollaborative Container-Based Cloud Service Operation State Continuous Monitoring Framework(NCCMF),based on relevant standards.NCCMF operates without the CSP’s collaboration by:1)establishing a scalable supervisory index system through the identification of security responsibilities for each role,and 2)designing a Continuous Metrics Supervision Protocol(CMA)to automate the negotiation of supervisory metrics.The framework also outlines the supervision process for cloud services across different deployment models.Experimental results demonstrate that NCCMF effectively monitors the operational state of two real-world IoT(Internet of Things)cloud services,with an average supervision error of less than 15%.展开更多
This study analyzes live facial videos for recognizing nonverbal learning-related facial movements and head poses to discover the learning status of students. First, color and depth facial videos captured by a Kinect ...This study analyzes live facial videos for recognizing nonverbal learning-related facial movements and head poses to discover the learning status of students. First, color and depth facial videos captured by a Kinect are analyzed for face tracking using a three-dimensional （3D） active appearance model （AAM）. Second, the facial feature vector sequences are used to train hidden Markov models （HMMs） to recognize seven learning-related facial movements （smile, blink, frown, shake, nod, yawn, and talk）. The final stage involves the analysis of the facial movement vector sequence to evaluate three status scores （understanding, interaction, and consciousness）, each represents the learning status of a student and is helpful to both teachers and students for improving teaching and learning. Five teaching activities demonstrate that the proposed learning status analysis system promotes the interpersonal communication between teachers and students.展开更多
Assessment of the current status of Lake Baikal proved to be based on changes in natural (“preindustrial”) chemical content in basic abiotic and biological compartments of the Lake geosystem. This approach was used ...Assessment of the current status of Lake Baikal proved to be based on changes in natural (“preindustrial”) chemical content in basic abiotic and biological compartments of the Lake geosystem. This approach was used to evaluate background “base-line levels” of 6 major and about 50 minor and trace ele-ments in the Lake Baikal water body using a number of most reliable data re-ported within 1992-2012. In terms of environment geochemistry Baikal is one of the purest water reservoirs on the Earth. A simple mass balance model was proposed for assessing possible anthropogenic impact on Baikal water geo-chemistry. Estimations of change trends showed that only for Na+, SO42-, Cl- and Mo growth rate of their average concentrations in the Lake occurred to be 1%, 3%, 7% and 2% in every 10 years. Space-time monitoring schedules for all water body compartments of the Lake are proposed as well as similar moni-toring programs for tributaries, precipitations, bottom sediments, aquatic biota.展开更多
Under the background of rapid social development, industrial production scale expansion, economic growth rate increases, but in the process of industrial waste water, waste and also cause serious harm to the ecologica...Under the background of rapid social development, industrial production scale expansion, economic growth rate increases, but in the process of industrial waste water, waste and also cause serious harm to the ecological environment, make water pollution, not only affect the ecological stability and balance, but also affect peoples quality of life and biological living environment. Surface water monitoring based on environmental testing can test the quality of surface water, and the pollution source and pollution degree can be analyzed according to the comparative standard value of the test results, so that the problem can be accurately and effectively formulated. But now surface water monitoring level is insufficient, there are many problems in the actual stage, need relevant departments and personnel to realize the importance of surface water monitoring, detailed analysis of surface water monitoring status, understand the monitoring technology progress, and according to the surface water monitoring work content, the actual situation, combined with the ecological environment protection requirements to formulate corresponding improvement measures, to clarify the direction of surface water monitoring work, improve the level of surface water monitoring work. This paper analyzes the current situation of surface water monitoring in environmental testing, and puts forward some suggestions for reference.展开更多
With the rapid development of economy, great changes have taken place in our lives, and the quality and level of our lives are constantly improving. However, the problem of environmental pollution is also getting wors...With the rapid development of economy, great changes have taken place in our lives, and the quality and level of our lives are constantly improving. However, the problem of environmental pollution is also getting worse. Environmental issues are related to our survival and development, so it is particularly important to do a good job in protecting the ecological environment. Therefore, it is particularly important to carry out surface water testing, and there are still many problems to be solved in surface water testing. This paper discusses the related problems and countermeasures of surface water detection in environmental monitoring to provide reference for surface water monitoring.展开更多
Abundant system operation state information is included in the electrical signal of the hydraulic system motor.How to accurately extract and classify the operation information of electrical signal is the key to realiz...Abundant system operation state information is included in the electrical signal of the hydraulic system motor.How to accurately extract and classify the operation information of electrical signal is the key to realize the condition monitoring of hydraulic system.The early fault characteristics of hydraulic gear pump hidden in the motor current signal are weak and difficult to extract by traditional time-frequency analysis.Based on the correlation coefficient and artificial bee colony algorithm(ABC),the parameter optimization of variational mode decomposition(VMD)is realized in this paper.At the same time,the principle of maximum signal correlation coefficient and kurtosis value is adopted to determine the effective intrinsic mode function(IMF).Moreover,the permutation entropy(PE)and root mean square(RMS)of the effective IMF components are input into the deep belief network(DBN-DNN)as high-dimensional feature vectors.The operation state of gear pump is monitored.The results show that the weak characteristics of current signal of gear pump fault are accurately and stably extracted by this method.The running state of gear pump is monitored and the accuracy of gear fault diagnosis is improved.展开更多
In recent years, with the development of China's highway cause, the bridge construction has also entered a new historical period, and the level of bridge engineering technology has been significantly improved, and...In recent years, with the development of China's highway cause, the bridge construction has also entered a new historical period, and the level of bridge engineering technology has been significantly improved, and promoted the development of the bridge cause. But the development of bridge maintenance and management is relatively slow. In order to change this situation, give full play to the role of bridge and extend the service life, computer digital information technology and sensing technology are used to monitor the health status of large bridge structure, accurately evaluate the performance of large bridge, and provide data and technical basis. Combined with the health and safety monitoring system of Jingyue Yangtze River Highway Bridge, this paper analyzes and evaluates the safety and reliability of the stress and deformation of the structure, providing effective technical support for bridge maintenance and management decision.展开更多
Power grid is an indispensable infrastructure in modern society,in order to ensure the normal operation of the grid,online non-contact monitoring of high-voltage lines is essential.In this work,a‘capacitor-laser diod...Power grid is an indispensable infrastructure in modern society,in order to ensure the normal operation of the grid,online non-contact monitoring of high-voltage lines is essential.In this work,a‘capacitor-laser diode(LD)-capacitor’structure,namely,laser diode in capacitors(LDIC),that can be used for non-contact monitoring of high-voltage(HV)line status by directly transferring the status information of the HV line to modulated laser pulses is proposed.The proposed LDIC can accurately extract the real-time voltage changes on the HV line with an accuracy level of 0.959%.Because the LDIC is sensitive to high-frequency electromagnetic field,the LDIC is successfully utilised to detect the external electromagnetic interference(EMI)to obtain the intensity and frequency of the external EMI.Additionally,the amplitude and frequency of the HV line vibration can be accurately monitored by using the LDIC.For the third-order curve fitting of vibration amplitude,the average error is only 0.00867,and the average error of linear fitting of vibration frequency is as low as 0.00655.This work provides a novel approach for the online monitoring of the HV line status and a new supplement for the development of power grid technology.展开更多
Rapidly-advancing microneedle-based bioelectronics integrated with electrical stimulation(ES)therapy exhibit significant potential for improving chronic wound management.Herein,bio-inspired by the serrated structure o...Rapidly-advancing microneedle-based bioelectronics integrated with electrical stimulation(ES)therapy exhibit significant potential for improving chronic wound management.Herein,bio-inspired by the serrated structure of bee-stingers,we developed a temperature-sensitive,two-stage microneedle-based electro active platform(GP-PPy/PLA-MN)featuring rivet-like micros tructures that integrates intelligent,precise drug-releasing,ES-transmission,and real-time wound-assessment monitoring for comprehensive chronic wound-management and diagnostic therapy.The bionic-design mechanically anchors the microneedle beneath the skin's dermis,while GP-PPy/PLA-MN demonstrates versatile therapeutic characteristics,including outstanding biocompatibility,antimicrobial properties,and antimigratory origins.The GP-PPy/PLA-MN enables the sustained release of insulin at body temperature for up to24 hours through the poly-N-isopropyl acrylamide grafted amidated-gelatin-based thermo-sensitive hydrogel at the needle-tip,thereby providing long-term stable blood glucose control.GP-PPy/PLA-MN indicates its potential as a novel bioelectronics-based patch to record the temperature and humidity during the wound-healing process,realizing significant wound diagnosis and real-time wound assessment,and fundamentally facilitating the therapeutic efficacy by supplying solid data to protect the clinical practice.Extensive in vitro and in vivo studies have demonstrated that GP-PPy/PLA-MN can provide effective ES and sustained drug release,thereby promoting chronic wound healing and increasing the wound healing rate by 20%compared to the control group after 14 days of treatment.This innovative approach combines bioelectronics with intelligent drug delivery and microneedling technology to effectively address the critical challenges of chronic wound management,offering promising prospects for precision diagnostics and therapeutic interventions.展开更多
Rockburst is a common dynamic geological hazard,frequently occurring in underground engineering(e.g.,TBM tunnelling and deep mining).In order to achieve rockburst monitoring and warning,the microseismic moni-toring te...Rockburst is a common dynamic geological hazard,frequently occurring in underground engineering(e.g.,TBM tunnelling and deep mining).In order to achieve rockburst monitoring and warning,the microseismic moni-toring technique has been widely used in the field.However,the microseismic source location has always been a challenge,playing a vital role in the precise prevention and control of rockburst.To this end,this study proposes a novel microseismic source location model that considers the anisotropy of P-wave velocity.On the one hand,it assigns a unique P-wave velocity to each propagation path,abandoning the assumption of a homogeneous ve-locity field.On the other hand,it treats the P-wave velocity as a co-inversion parameter along with the source location,avoiding the predetermination of P-wave velocity.To solve this model,three various metaheuristic multi-objective optimization algorithms are integrated with it,including the whale optimization algorithm,the butterfly optimization algorithm,and the sparrow search algorithm.To demonstrate the advantages of the model in terms of localization accuracy,localization efficiency,and solution stability,four blasting cases are collected from a water diversion tunnel project in Xinjiang,China.Finally,the effect of the number of involved sensors on the microseismic source location is discussed.展开更多
Chinese sucker( Myxocyprinus asiatius) is a national secondary protection animal in China,as well as unique economic fish in China having extremely important scientific research value and edible value. With the aggrav...Chinese sucker( Myxocyprinus asiatius) is a national secondary protection animal in China,as well as unique economic fish in China having extremely important scientific research value and edible value. With the aggravation of water pollution and the massive construction of water conservancy and hydropower projects,the natural spawning ground of Chinese sucker has been seriously damaged. The current number of wild resources has decreased sharply,and the decreasing trend is continuing. This paper summarized the current resource status and monitoring and assessment methods of Chinese suckers,and put forward the research prospect,so as to provide theoretical reference and technical support for resource protection and development and utilization of Chinese sucker in China.展开更多
This study focused on the mechanical behavior of a deep-buried tunnel constructed in horizontally layered limestone,and investigated the effect of a new combined rockboltecable support system on the tunnel response.Th...This study focused on the mechanical behavior of a deep-buried tunnel constructed in horizontally layered limestone,and investigated the effect of a new combined rockboltecable support system on the tunnel response.The Yujingshan Tunnel,excavated through a giant karst cave,was used as a case study.Firstly,a multi-objective optimization model for the rockboltecable support was proposed by using fuzzy mathematics and multi-objective comprehensive decision-making principles.Subsequently,the parameters of the surrounding rock were calibrated by comparing the simulation results obtained by the discrete element method(DEM)with the field monitoring data to obtain an optimized support scheme based on the optimization model.Finally,the optimization scheme was applied to the karst cave section,which was divided into the B-and C-shaped sections.The distribution range of the rockboltecable support in the C-shaped section was larger than that in the B-shaped section.The field monitoring results,including tunnel crown settlement,horizontal convergence,and axial force of the rockboltecable system,were analyzed to assess the effectiveness of the optimization scheme.The maximum crown settlement and horizontal convergence were measured to be 25.9 mm and 35 mm,accounting for 0.1%and 0.2%of the tunnel height and span,respectively.Although the C-shaped section had poorer rock properties than the B-shaped section,the crown settlement and horizontal convergence in the C-shaped section ranged from 46%to 97%of those observed in the B-shaped section.The cable axial force in the Bshaped section was approximately 60%of that in the C-shaped section.The axial force in the crown rockbolt was much smaller than that in the sidewall rockbolt.Field monitoring results demonstrated that the optimized scheme effectively controlled the deformation of the layered surrounding rock,ensuring that it remained within a safe range.These results provide valuable references for the design of support systems in deep-buried tunnels situated in layered rock masses.展开更多
Purpose–This study aimed to facilitate a rapid evaluation of track service status and vehicle ride comfort based on car body acceleration.Consequently,a low-cost,data-driven approach was proposed for analyzing speed-...Purpose–This study aimed to facilitate a rapid evaluation of track service status and vehicle ride comfort based on car body acceleration.Consequently,a low-cost,data-driven approach was proposed for analyzing speed-related acceleration limits in metro systems.Design/methodology/approach–A portable sensing terminal was developed to realize easy and efficient detection of car body acceleration.Further,field measurements were performed on a 51.95-km metro line.Data from 272 metro sections were tested as a case study,and a quantile regression method was proposed to fit the control limits of the car body acceleration at different speeds using the measured data.Findings–First,the frequency statistics of the measured data in the speed-acceleration dimension indicated that the car body acceleration was primarily concentrated within the constant speed stage,particularly at speeds of 15.4,18.3,and 20.9 m/s.Second,resampling was performed according to the probability density distribution of car body acceleration for different speed domains to achieve data balance.Finally,combined with the traditional linear relationship between speed and acceleration,the statistical relationships between the speed and car body acceleration under different quantiles were determined.We concluded the lateral/vertical quantiles of 0.8989/0.9895,0.9942/0.997,and 0.9998/0.993 as being excellent,good,and qualified control limits,respectively,for the lateral and vertical acceleration of the car body.In addition,regression lines for the speedrelated acceleration limits at other quantiles(0.5,0.75,2s,and 3s)were obtained.Originality/value–The proposed method is expected to serve as a reference for further studies on speedrelated acceleration limits in rail transit systems.展开更多
This study proposes the use of a novel integrated framework for 2D en route airspace sub-sectorization.The integrated framework combines the multi-commodity flow optimization approach,complex network cluster-ing appro...This study proposes the use of a novel integrated framework for 2D en route airspace sub-sectorization.The integrated framework combines the multi-commodity flow optimization approach,complex network cluster-ing approach,and Minimum Bounding Geometry(MBG)-coupled Rule-based Approach for boundary design.A decomposition-based discrete particle swarm optimization(DPSO)is used to solve the clustering problem.The output of the flow optimization is used as a guiding standard for the DPSO.Experimentations were performed using the Indian airspace sector to validate the framework and DPSO was run for different maximum number of generations(maxgen).The findings reveal that the multi-commodity flow approach captures system-wide flow operations.Clustering results corresponding to maxgen=100 and maxgen=150 perform best in terms of equitable and balanced distribution of cluster size and traffic load.The MBG-coupled Rule-based Approach leads to com-pact and convex sub-sector boundary design.Major implications of this research include dynamic adaptability of the integrated framework,increased sensitivity of sector design to network evolution,and a computationally tractable framework.The higher controllability of the proposed framework also offers an increased acceptance among practitioners.展开更多
Isothermal forging stands as an effective technology for the production of large-scale titanium alloy multi-rib components.However,challenges have persisted,including die underfilling and strain concentration due to t...Isothermal forging stands as an effective technology for the production of large-scale titanium alloy multi-rib components.However,challenges have persisted,including die underfilling and strain concentration due to the complex material flow and heterogeneous deformation within the forging die cavity.While approaches centered on optimized billet designs have mitigated these challenges,uncertainties in process parameters continue to introduce unacceptable variations in forming accuracy and stability.To tackle this issue,this study introduced a multi-objective robust optimization approach for billet design,accounting for the multi-rib eigenstructure and potential uncertainties.The approach includes finite element(FE)modeling for analyzing the die-filling and strain inhomogeneity within the multi-rib eigenstructure.Furthermore,it integrated image acquisition perception and feed back technologies(IAPF)for real-time monitoring of material flow and filling sequences within die rib-grooves,validating the accuracy of the FE modeling.By incorporating dimensional parameters of the billet and uncertainty factors,including friction,draft angle,forming temperature,speed,and deviations in billet and die,quantitative analyses on the rib-groove filling and strain inhomogeneity with fluctuation were conducted.Subsequently,a dual-response surface model was developed for statistical analysis of the cavity filling and strain homogeneity.Finally,the robust optimization was processed using a non-dominated sorting genetic algorithm II(NSGA-II)and validated using the IAPF technologies.The proposed approach enables robust design enhancements for rib-groove filling and strain homogeneity in titanium alloy multi-rib components.展开更多
基金This work was based on a previous article presented in 1st Three Gorges Research Forum on Environment and Economy, TGRF2007, at Chongqing University, July 18-19, 2007.
文摘To fit the complicated geographic conditions of the Three Gorges Reservoir area, a two-level multi-objective monitoring system was developed to monitor the atmosphere of the area. Statistical analysis of environmental monitoring data and the macro control principle were employed to configure the upper layer. The lower layer was designed by the application of the thumb rule to a local terrain and specific point sources of pollution therein. The optimized two-level system comprises an upper layer of 16 monitoring stations distributed at places of diverse geographical, ecological, economical and social characteristics, and a lower layer of ]6 sub-machines at each monitoring station of the upper layer. This optimal outcome fits the complicated conditions of the Three Gorges Reservoir area, substantially cuts down the installation cost and the operation cost, and provides accurate monitoring data of atmosphere over the entire area with a high resolution.
基金supported in part by the Intelligent Policing and National Security Risk Management Laboratory 2023 Opening Project(No.ZHKFYB2304)the Fundamental Research Funds for the Central Universities(Nos.SCU2023D008,2023SCU12129)+2 种基金the Natural Science Foundation of Sichuan Province(No.2024NSFSC1449)the Science and Engineering Connotation Development Project of Sichuan University(No.2020SCUNG129)the Key Laboratory of Data Protection and Intelligent Management(Sichuan University),Ministry of Education.
文摘The security performance of cloud services is a key factor influencing users’selection of Cloud Service Providers(CSPs).Continuous monitoring of the security status of cloud services is critical.However,existing research lacks a practical framework for such ongoing monitoring.To address this gap,this paper proposes the first NonCollaborative Container-Based Cloud Service Operation State Continuous Monitoring Framework(NCCMF),based on relevant standards.NCCMF operates without the CSP’s collaboration by:1)establishing a scalable supervisory index system through the identification of security responsibilities for each role,and 2)designing a Continuous Metrics Supervision Protocol(CMA)to automate the negotiation of supervisory metrics.The framework also outlines the supervision process for cloud services across different deployment models.Experimental results demonstrate that NCCMF effectively monitors the operational state of two real-world IoT(Internet of Things)cloud services,with an average supervision error of less than 15%.
文摘This study analyzes live facial videos for recognizing nonverbal learning-related facial movements and head poses to discover the learning status of students. First, color and depth facial videos captured by a Kinect are analyzed for face tracking using a three-dimensional （3D） active appearance model （AAM）. Second, the facial feature vector sequences are used to train hidden Markov models （HMMs） to recognize seven learning-related facial movements （smile, blink, frown, shake, nod, yawn, and talk）. The final stage involves the analysis of the facial movement vector sequence to evaluate three status scores （understanding, interaction, and consciousness）, each represents the learning status of a student and is helpful to both teachers and students for improving teaching and learning. Five teaching activities demonstrate that the proposed learning status analysis system promotes the interpersonal communication between teachers and students.
文摘Assessment of the current status of Lake Baikal proved to be based on changes in natural (“preindustrial”) chemical content in basic abiotic and biological compartments of the Lake geosystem. This approach was used to evaluate background “base-line levels” of 6 major and about 50 minor and trace ele-ments in the Lake Baikal water body using a number of most reliable data re-ported within 1992-2012. In terms of environment geochemistry Baikal is one of the purest water reservoirs on the Earth. A simple mass balance model was proposed for assessing possible anthropogenic impact on Baikal water geo-chemistry. Estimations of change trends showed that only for Na+, SO42-, Cl- and Mo growth rate of their average concentrations in the Lake occurred to be 1%, 3%, 7% and 2% in every 10 years. Space-time monitoring schedules for all water body compartments of the Lake are proposed as well as similar moni-toring programs for tributaries, precipitations, bottom sediments, aquatic biota.
文摘Under the background of rapid social development, industrial production scale expansion, economic growth rate increases, but in the process of industrial waste water, waste and also cause serious harm to the ecological environment, make water pollution, not only affect the ecological stability and balance, but also affect peoples quality of life and biological living environment. Surface water monitoring based on environmental testing can test the quality of surface water, and the pollution source and pollution degree can be analyzed according to the comparative standard value of the test results, so that the problem can be accurately and effectively formulated. But now surface water monitoring level is insufficient, there are many problems in the actual stage, need relevant departments and personnel to realize the importance of surface water monitoring, detailed analysis of surface water monitoring status, understand the monitoring technology progress, and according to the surface water monitoring work content, the actual situation, combined with the ecological environment protection requirements to formulate corresponding improvement measures, to clarify the direction of surface water monitoring work, improve the level of surface water monitoring work. This paper analyzes the current situation of surface water monitoring in environmental testing, and puts forward some suggestions for reference.
文摘With the rapid development of economy, great changes have taken place in our lives, and the quality and level of our lives are constantly improving. However, the problem of environmental pollution is also getting worse. Environmental issues are related to our survival and development, so it is particularly important to do a good job in protecting the ecological environment. Therefore, it is particularly important to carry out surface water testing, and there are still many problems to be solved in surface water testing. This paper discusses the related problems and countermeasures of surface water detection in environmental monitoring to provide reference for surface water monitoring.
基金National Natural Science Foundation of China(No.51675399)。
文摘Abundant system operation state information is included in the electrical signal of the hydraulic system motor.How to accurately extract and classify the operation information of electrical signal is the key to realize the condition monitoring of hydraulic system.The early fault characteristics of hydraulic gear pump hidden in the motor current signal are weak and difficult to extract by traditional time-frequency analysis.Based on the correlation coefficient and artificial bee colony algorithm(ABC),the parameter optimization of variational mode decomposition(VMD)is realized in this paper.At the same time,the principle of maximum signal correlation coefficient and kurtosis value is adopted to determine the effective intrinsic mode function(IMF).Moreover,the permutation entropy(PE)and root mean square(RMS)of the effective IMF components are input into the deep belief network(DBN-DNN)as high-dimensional feature vectors.The operation state of gear pump is monitored.The results show that the weak characteristics of current signal of gear pump fault are accurately and stably extracted by this method.The running state of gear pump is monitored and the accuracy of gear fault diagnosis is improved.
文摘In recent years, with the development of China's highway cause, the bridge construction has also entered a new historical period, and the level of bridge engineering technology has been significantly improved, and promoted the development of the bridge cause. But the development of bridge maintenance and management is relatively slow. In order to change this situation, give full play to the role of bridge and extend the service life, computer digital information technology and sensing technology are used to monitor the health status of large bridge structure, accurately evaluate the performance of large bridge, and provide data and technical basis. Combined with the health and safety monitoring system of Jingyue Yangtze River Highway Bridge, this paper analyzes and evaluates the safety and reliability of the stress and deformation of the structure, providing effective technical support for bridge maintenance and management decision.
基金supported by National Key R&D Program of China under Grant No.2021YFB3600400Mindu Innovation Laboratory Project under Grant No.2020ZZ113.
文摘Power grid is an indispensable infrastructure in modern society,in order to ensure the normal operation of the grid,online non-contact monitoring of high-voltage lines is essential.In this work,a‘capacitor-laser diode(LD)-capacitor’structure,namely,laser diode in capacitors(LDIC),that can be used for non-contact monitoring of high-voltage(HV)line status by directly transferring the status information of the HV line to modulated laser pulses is proposed.The proposed LDIC can accurately extract the real-time voltage changes on the HV line with an accuracy level of 0.959%.Because the LDIC is sensitive to high-frequency electromagnetic field,the LDIC is successfully utilised to detect the external electromagnetic interference(EMI)to obtain the intensity and frequency of the external EMI.Additionally,the amplitude and frequency of the HV line vibration can be accurately monitored by using the LDIC.For the third-order curve fitting of vibration amplitude,the average error is only 0.00867,and the average error of linear fitting of vibration frequency is as low as 0.00655.This work provides a novel approach for the online monitoring of the HV line status and a new supplement for the development of power grid technology.
基金financially supported by the National Natural Science Foun-dation of China(22278257)the Key R&D Program of Shaanxi Province(2024SF-YBXM-586)the Project of Innovation Capability Support Program in Shaanxi Province(2024ZC-KJXX-005)。
文摘Rapidly-advancing microneedle-based bioelectronics integrated with electrical stimulation(ES)therapy exhibit significant potential for improving chronic wound management.Herein,bio-inspired by the serrated structure of bee-stingers,we developed a temperature-sensitive,two-stage microneedle-based electro active platform(GP-PPy/PLA-MN)featuring rivet-like micros tructures that integrates intelligent,precise drug-releasing,ES-transmission,and real-time wound-assessment monitoring for comprehensive chronic wound-management and diagnostic therapy.The bionic-design mechanically anchors the microneedle beneath the skin's dermis,while GP-PPy/PLA-MN demonstrates versatile therapeutic characteristics,including outstanding biocompatibility,antimicrobial properties,and antimigratory origins.The GP-PPy/PLA-MN enables the sustained release of insulin at body temperature for up to24 hours through the poly-N-isopropyl acrylamide grafted amidated-gelatin-based thermo-sensitive hydrogel at the needle-tip,thereby providing long-term stable blood glucose control.GP-PPy/PLA-MN indicates its potential as a novel bioelectronics-based patch to record the temperature and humidity during the wound-healing process,realizing significant wound diagnosis and real-time wound assessment,and fundamentally facilitating the therapeutic efficacy by supplying solid data to protect the clinical practice.Extensive in vitro and in vivo studies have demonstrated that GP-PPy/PLA-MN can provide effective ES and sustained drug release,thereby promoting chronic wound healing and increasing the wound healing rate by 20%compared to the control group after 14 days of treatment.This innovative approach combines bioelectronics with intelligent drug delivery and microneedling technology to effectively address the critical challenges of chronic wound management,offering promising prospects for precision diagnostics and therapeutic interventions.
基金supported by the National Natural Science Founda-tion of China under Grant Nos.42472351,42177140,52404127,and 42207235the Natural Science Foundation of Hubei Province under Grant No.2024AFD359+1 种基金the Young Elite Scientist Sponsorship Program by CAST under Grant No.YESS20230742the China Postdoctoral Science Foundation Program under Grant No.2024T170684.
文摘Rockburst is a common dynamic geological hazard,frequently occurring in underground engineering(e.g.,TBM tunnelling and deep mining).In order to achieve rockburst monitoring and warning,the microseismic moni-toring technique has been widely used in the field.However,the microseismic source location has always been a challenge,playing a vital role in the precise prevention and control of rockburst.To this end,this study proposes a novel microseismic source location model that considers the anisotropy of P-wave velocity.On the one hand,it assigns a unique P-wave velocity to each propagation path,abandoning the assumption of a homogeneous ve-locity field.On the other hand,it treats the P-wave velocity as a co-inversion parameter along with the source location,avoiding the predetermination of P-wave velocity.To solve this model,three various metaheuristic multi-objective optimization algorithms are integrated with it,including the whale optimization algorithm,the butterfly optimization algorithm,and the sparrow search algorithm.To demonstrate the advantages of the model in terms of localization accuracy,localization efficiency,and solution stability,four blasting cases are collected from a water diversion tunnel project in Xinjiang,China.Finally,the effect of the number of involved sensors on the microseismic source location is discussed.
基金Supported by College Students'Practice Innovation Training Program of Jiangsu Province(201312806015Y)Research Project of Jiangsu Agri-animal Husbandry Vocational College(NSFYB1408)Qing Lan Project for Talent Training in Colleges and Universities in Jiangsu Province(00000216014)
文摘Chinese sucker( Myxocyprinus asiatius) is a national secondary protection animal in China,as well as unique economic fish in China having extremely important scientific research value and edible value. With the aggravation of water pollution and the massive construction of water conservancy and hydropower projects,the natural spawning ground of Chinese sucker has been seriously damaged. The current number of wild resources has decreased sharply,and the decreasing trend is continuing. This paper summarized the current resource status and monitoring and assessment methods of Chinese suckers,and put forward the research prospect,so as to provide theoretical reference and technical support for resource protection and development and utilization of Chinese sucker in China.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No.2023JBZY024)Beijing Natural Science Foundation (Grant No.9244040)opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology (Grant No.SKLGP2023K015).
文摘This study focused on the mechanical behavior of a deep-buried tunnel constructed in horizontally layered limestone,and investigated the effect of a new combined rockboltecable support system on the tunnel response.The Yujingshan Tunnel,excavated through a giant karst cave,was used as a case study.Firstly,a multi-objective optimization model for the rockboltecable support was proposed by using fuzzy mathematics and multi-objective comprehensive decision-making principles.Subsequently,the parameters of the surrounding rock were calibrated by comparing the simulation results obtained by the discrete element method(DEM)with the field monitoring data to obtain an optimized support scheme based on the optimization model.Finally,the optimization scheme was applied to the karst cave section,which was divided into the B-and C-shaped sections.The distribution range of the rockboltecable support in the C-shaped section was larger than that in the B-shaped section.The field monitoring results,including tunnel crown settlement,horizontal convergence,and axial force of the rockboltecable system,were analyzed to assess the effectiveness of the optimization scheme.The maximum crown settlement and horizontal convergence were measured to be 25.9 mm and 35 mm,accounting for 0.1%and 0.2%of the tunnel height and span,respectively.Although the C-shaped section had poorer rock properties than the B-shaped section,the crown settlement and horizontal convergence in the C-shaped section ranged from 46%to 97%of those observed in the B-shaped section.The cable axial force in the Bshaped section was approximately 60%of that in the C-shaped section.The axial force in the crown rockbolt was much smaller than that in the sidewall rockbolt.Field monitoring results demonstrated that the optimized scheme effectively controlled the deformation of the layered surrounding rock,ensuring that it remained within a safe range.These results provide valuable references for the design of support systems in deep-buried tunnels situated in layered rock masses.
基金the National Natural Science Foundation of China(NSFC)under No.52308473the National KeyR&DProgram under No.2022YFB2603301the China Postdoctoral Science Foundation funded project(Certificate Number:2023M743895).
文摘Purpose–This study aimed to facilitate a rapid evaluation of track service status and vehicle ride comfort based on car body acceleration.Consequently,a low-cost,data-driven approach was proposed for analyzing speed-related acceleration limits in metro systems.Design/methodology/approach–A portable sensing terminal was developed to realize easy and efficient detection of car body acceleration.Further,field measurements were performed on a 51.95-km metro line.Data from 272 metro sections were tested as a case study,and a quantile regression method was proposed to fit the control limits of the car body acceleration at different speeds using the measured data.Findings–First,the frequency statistics of the measured data in the speed-acceleration dimension indicated that the car body acceleration was primarily concentrated within the constant speed stage,particularly at speeds of 15.4,18.3,and 20.9 m/s.Second,resampling was performed according to the probability density distribution of car body acceleration for different speed domains to achieve data balance.Finally,combined with the traditional linear relationship between speed and acceleration,the statistical relationships between the speed and car body acceleration under different quantiles were determined.We concluded the lateral/vertical quantiles of 0.8989/0.9895,0.9942/0.997,and 0.9998/0.993 as being excellent,good,and qualified control limits,respectively,for the lateral and vertical acceleration of the car body.In addition,regression lines for the speedrelated acceleration limits at other quantiles(0.5,0.75,2s,and 3s)were obtained.Originality/value–The proposed method is expected to serve as a reference for further studies on speedrelated acceleration limits in rail transit systems.
基金PMRF PM/MHRD-20-16823.03 for the financial support。
文摘This study proposes the use of a novel integrated framework for 2D en route airspace sub-sectorization.The integrated framework combines the multi-commodity flow optimization approach,complex network cluster-ing approach,and Minimum Bounding Geometry(MBG)-coupled Rule-based Approach for boundary design.A decomposition-based discrete particle swarm optimization(DPSO)is used to solve the clustering problem.The output of the flow optimization is used as a guiding standard for the DPSO.Experimentations were performed using the Indian airspace sector to validate the framework and DPSO was run for different maximum number of generations(maxgen).The findings reveal that the multi-commodity flow approach captures system-wide flow operations.Clustering results corresponding to maxgen=100 and maxgen=150 perform best in terms of equitable and balanced distribution of cluster size and traffic load.The MBG-coupled Rule-based Approach leads to com-pact and convex sub-sector boundary design.Major implications of this research include dynamic adaptability of the integrated framework,increased sensitivity of sector design to network evolution,and a computationally tractable framework.The higher controllability of the proposed framework also offers an increased acceptance among practitioners.
基金Supported by National Natural Science Foundation of China(Grant No.52005241)Jiangxi Provincial Natural Science Foundation(Grant Nos.20232BAB204050,20224BAB204045)China Scholarship Council(Grant No.202208360107).
文摘Isothermal forging stands as an effective technology for the production of large-scale titanium alloy multi-rib components.However,challenges have persisted,including die underfilling and strain concentration due to the complex material flow and heterogeneous deformation within the forging die cavity.While approaches centered on optimized billet designs have mitigated these challenges,uncertainties in process parameters continue to introduce unacceptable variations in forming accuracy and stability.To tackle this issue,this study introduced a multi-objective robust optimization approach for billet design,accounting for the multi-rib eigenstructure and potential uncertainties.The approach includes finite element(FE)modeling for analyzing the die-filling and strain inhomogeneity within the multi-rib eigenstructure.Furthermore,it integrated image acquisition perception and feed back technologies(IAPF)for real-time monitoring of material flow and filling sequences within die rib-grooves,validating the accuracy of the FE modeling.By incorporating dimensional parameters of the billet and uncertainty factors,including friction,draft angle,forming temperature,speed,and deviations in billet and die,quantitative analyses on the rib-groove filling and strain inhomogeneity with fluctuation were conducted.Subsequently,a dual-response surface model was developed for statistical analysis of the cavity filling and strain homogeneity.Finally,the robust optimization was processed using a non-dominated sorting genetic algorithm II(NSGA-II)and validated using the IAPF technologies.The proposed approach enables robust design enhancements for rib-groove filling and strain homogeneity in titanium alloy multi-rib components.
