A great number of visual simultaneous localization and mapping(VSLAM)systems need to assume static features in the environment.However,moving objects can vastly impair the performance of a VSLAM system which relies on...A great number of visual simultaneous localization and mapping(VSLAM)systems need to assume static features in the environment.However,moving objects can vastly impair the performance of a VSLAM system which relies on the static-world assumption.To cope with this challenging topic,a real-time and robust VSLAM system based on ORB-SLAM2 for dynamic environments was proposed.To reduce the influence of dynamic content,we incorporate the deep-learning-based object detection method in the visual odometry,then the dynamic object probability model is added to raise the efficiency of object detection deep neural network and enhance the real-time performance of our system.Experiment with both on the TUM and KITTI benchmark dataset,as well as in a real-world environment,the results clarify that our method can significantly reduce the tracking error or drift,enhance the robustness,accuracy and stability of the VSLAM system in dynamic scenes.展开更多
While different species in nature have safely solved the problem of navigation in a dynamic environment, this remains a challenging task for researchers around the world. The paper addresses the problem of autonomous ...While different species in nature have safely solved the problem of navigation in a dynamic environment, this remains a challenging task for researchers around the world. The paper addresses the problem of autonomous navigation in an unknown dynamic environment for a single and a group of three wheeled omnidirectional mobile robots(TWOMRs). The robot has to track a dynamic target while avoiding dynamic obstacles and dynamic walls in an unknown and very dense environment. It adopts a behavior-based controller that consists of four behaviors: "target tracking", "obstacle avoidance", "dynamic wall following" and "avoid robots". The paper considers the problem of kinematic saturation. In addition, it introduces a strategy for predicting the velocity of dynamic obstacles based on two successive measurements of the ultrasonic sensors to calculate the velocity of the obstacle expressed in the sensor frame. Furthermore, the paper proposes a strategy to deal with dynamic walls even when they have U-like or V-like shapes. The approach can also deal with the formation control of a group of robots based on the leader-follower structure and the behavior-based control, where the robots have to get together and maintain a given formation while navigating toward the target, avoiding obstacles and walls in a dynamic environment. The effectiveness of the proposed approaches is demonstrated via simulation.展开更多
This study presents a statistical landslide susceptibility assessment(LSA) in a dynamic environment. The study area is located in the eastern part of Lanzhou, NW China. The Lanzhou area has exhibited rapid urbanizatio...This study presents a statistical landslide susceptibility assessment(LSA) in a dynamic environment. The study area is located in the eastern part of Lanzhou, NW China. The Lanzhou area has exhibited rapid urbanization rates over the past decade associated with greening, continuous land use change, and geomorphic reshaping activities. To consider the dynamics of the environment in the LSA, multitemporal data for landslide inventories and the corresponding causal factors were collected. The weights of evidence(Wof E) method was used to perform the LSA. Three time stamps, i.e., 2000, 2012, and 2016, were selected to assess the state of landslide susceptibility over time. The results show a clear evolution of the landslide susceptibility patterns that was mainly governed by anthropogenic activities directed toward generating safer building grounds for civil infrastructure. The low and very low susceptibility areas increased by approximately 10% between 2000 and 2016. At the same time, areas of medium, high and very high susceptibility zones decreased proportionally. Based on the results, an approach to design the statistical LSA under dynamic conditions is proposed, the issues and limitations of this approach are also discussed. The study shows that under dynamic conditions, the requirements for data quantity and quality increase significantly. A dynamic environment requires greater effort to estimate the causal relations between the landslides and controlling factors as well as for model validation.展开更多
A weighted time-based global hierarchical path planning method is proposed to obtain the global optimal path from the starting point to the destination with time optimal control. First, the grid-or graph-based modelin...A weighted time-based global hierarchical path planning method is proposed to obtain the global optimal path from the starting point to the destination with time optimal control. First, the grid-or graph-based modeling is performed and the environment is divided into a set of grids or nodes. Then two time-based features of time interval and time cost are presented. The time intervals for each grid are built, during each interval the condition of the grid remains stable, and a time cost of passing through the grid is defined and assigned to each interval. Furthermore, the weight is introduced for taking both time and distance into consideration, and thus a sequence of multiscale paths with total time cost can be achieved. Experimental results show that the proposed method can handle the complex dynamic environment, obtain the global time optimal path and has the potential to be applied to the autonomous robot navigation and traffic environment.展开更多
Moving humans,agents,and subjects bring many challenges to robot self‐localisation and environment perception.To adapt to dynamic environments,SLAM researchers typically apply several deep learning image segmentation...Moving humans,agents,and subjects bring many challenges to robot self‐localisation and environment perception.To adapt to dynamic environments,SLAM researchers typically apply several deep learning image segmentation models to eliminate these moving obstacles.However,these moving obstacle segmentation methods cost too much computation resource for the onboard processing of mobile robots.In the current industrial environment,mobile robot collaboration scenario,the noise of mobile robots could be easily found by on‐board audio‐sensing processors and the direction of sound sources can be effectively acquired by sound source estimation algorithms,but the distance estimation of sound sources is difficult.However,in the field of visual perception,the 3D structure information of the scene is relatively easy to obtain,but the recognition and segmentation of moving objects is more difficult.To address these problems,a novel vision‐audio fusion method that combines sound source localisation methods with a visual SLAM scheme is proposed,thereby eliminating the effect of dynamic obstacles on multi‐agent systems.Several heterogeneous robots experiments in different dynamic scenes indicate very stable self‐localisation and environment reconstruction performance of our method.展开更多
Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations,which appear in the form of a continuous moving object trajectory.How to accurately predi...Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations,which appear in the form of a continuous moving object trajectory.How to accurately predict the uncertain mobility of objects becomes an important and challenging problem.Existing algorithms for trajectory prediction in moving objects databases mainly focus on identifying frequent trajectory patterns,and do not take account of the effect of essential dynamic environmental factors.In this study,a general schema for predicting uncertain trajectories of moving objects with dynamic environment awareness is presented,and the key techniques in trajectory prediction arc addressed in detail.In order to accurately predict the trajectories,a trajectory prediction algorithm based on continuous time Bayesian networks（CTBNs） is improved and applied,which takes dynamic environmental factors into full consideration.Experiments conducted on synthetic trajectory data verify the effectiveness of the improved algorithm,which also guarantees the time performance as well.展开更多
To tackle the problem of simultaneous localization and mapping(SLAM) in dynamic environments, a novel algorithm using landscape theory of aggregation is presented. By exploiting the coherent explanation how actors for...To tackle the problem of simultaneous localization and mapping(SLAM) in dynamic environments, a novel algorithm using landscape theory of aggregation is presented. By exploiting the coherent explanation how actors form alignments in a game provided by the landscape theory of aggregation, the algorithm is able to explicitly deal with the ever-changing relationship between the static objects and the moving objects without any prior models of the moving objects. The effectiveness of the method has been validated by experiments in two representative dynamic environments: the campus road and the urban road.展开更多
A low frequency dynamic environment prediction of spacecraft using dynamic substructu- ring is presented. The dynamic environment could be used to describe the level of the excitation on the spacecraft itself and auxi...A low frequency dynamic environment prediction of spacecraft using dynamic substructu- ring is presented. The dynamic environment could be used to describe the level of the excitation on the spacecraft itself and auxiliary equipment. In addition, the dynamic environment is a criterion for the structural dynamic design as well as the ground verification test. The proposed prediction method could solve two major problems. The first is the time consumption of analyzing the whole spacecraft model due to the huge amount of degrees of freedom, and the second is multi-source for component structural dynamic models from distributive departments. To demonstrate the feasibility and efficien- cy, the proposed prediction method is applied to resolve a launching satellite case, and the results were compared with those obtained by the traditional prediction technology using the finite element method.展开更多
A project entitled‘Development of a Global High-resolution Marine Dynamic Environmental Forecasting System’has been funded by‘The Program on Marine Environmental Safety Guarantee’of The National Key Research and D...A project entitled‘Development of a Global High-resolution Marine Dynamic Environmental Forecasting System’has been funded by‘The Program on Marine Environmental Safety Guarantee’of The National Key Research and Development Program of China.This project will accomplish its objectives through basic theoretical research,model development and expansion,and system establishment and application,with a focus on four key issues separated into nine tasks.A series of research achievements have already been obtained,including datasets,observations,theories,and model results.展开更多
As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple r...As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple regression to examine the relationship between corporate financial slack and R ＆ D investment under dynamic environment, using the Malmquist index method based on DEA model to analyze the innovation efficiency of Chinese manufacturing industry during the period of2009-2013. The results show that： Financial slack and R ＆ D investment intensity presents inverted ＂U＂ type relationship in？sample？companies, and the relationship is positively regulated by environmental dynamism; Financial slack promotes R ＆ D investment but have lag effect.展开更多
As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple r...As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple regressionto examine the relationship between corporate financial slack and R ＆ D investment under dynamic environment, using the Malmquist index method based on DEA model to analyze the innovation efficiency of Chinese manufacturing industry during the period of 2009-2013. The results show that： Financial slack and R ＆ D investment intensity presents inverted ＂U＂ type relationship in？sample？companies, and the relationship is positively regulated by environmental dynamism; Financial slackpromotes R ＆ D investment but have lag effect.展开更多
In recent years, with the outbreak of epidemic infectious diseases and the increasing political and economic uncertainty, should enterprises make strategic changes in response to environmental changes in a timely mann...In recent years, with the outbreak of epidemic infectious diseases and the increasing political and economic uncertainty, should enterprises make strategic changes in response to environmental changes in a timely manner or maintain strategic consistency under the circumstances of increasing environmental dynamics? From the perspective of contingency, this paper studies the impact of corporate strategic changes on enterprises in the context of environmental dynamics, and conducts an empirical study on manufacturing enterprises listed in A shares from 2008 to 2020. It is found that corporate strategic changes in the context of environmental dynamics are beneficial to corporate performance, but also bring financial volatility.展开更多
This paper presents a visual simultaneous localization and mapping(SLAM)system designed for highly dynamic environments,capable of eliminating dynamic objects using only visual information.The proposed system integrat...This paper presents a visual simultaneous localization and mapping(SLAM)system designed for highly dynamic environments,capable of eliminating dynamic objects using only visual information.The proposed system integrates learning-based and geometry-based methods to address the challenges posed by moving objects.The learning-based approach leverages image segmentation to remove previously trained objects,whereas the geometry-based approach utilises point correlation to eliminate unseen objects.By complementing each other,these methods enhance the robustness of the SLAM system in dynamic sce-narios.Experimental results demonstrate that the proposed method effectively removes dynamic objects.Comparative studies with state-of-the-art algorithms further show that the proposed method achieves superior accuracy and robustness.展开更多
This paper presents a visual simultaneous localization and mapping(SLAM)system designed for highly dynamic environments,capable of eliminating dynamic objects using only visual information.The proposed system integrat...This paper presents a visual simultaneous localization and mapping(SLAM)system designed for highly dynamic environments,capable of eliminating dynamic objects using only visual information.The proposed system integrates learning-based and geometry-based methods to address the challenges posed by moving objects.The learning-based approach leverages image segmentation to remove previously trained objects,whereas the geometry-based approach utilises point correlation to eliminate unseen objects.By complementing each other,these methods enhance the robustness of the SLAM system in dynamic scenarios.Experimental results demonstrate that the proposed method effectively removes dynamic objects.Comparative studies with state-of-the-art algorithms further show that the proposed method achieves superior accuracy and robustness.展开更多
Grouting represents a reliable method for strengthening fractured rock masses and preventing seawater infiltration in subsea tunnel engineering. However, grouting composites are continuously subjected to harsh marine ...Grouting represents a reliable method for strengthening fractured rock masses and preventing seawater infiltration in subsea tunnel engineering. However, grouting composites are continuously subjected to harsh marine environments,experiencing both chemical and physical effects from high-concentration erosive seawater ions, elevated water pressure, and complex flow fields. This multi-factor erosion deterioration diminishes the waterproofing capabilities of grouting composites and threatens the service life of subsea tunnel linings. To investigate the erosion deteriortion mechanism induced by sulfate, erosion weakening experiments were conducted using a seawater flow simulation device. The research examined the compressive strength and permeability coefficient of grouting composites under different erosion durations, water-cement ratios, and grouting pressures. In the later stages of the experiment, the strength of grouting composites in the static water erosion control group(SEG) and dynamic water erosion group(DEG) decreased by 31.2% and 18.8%, respectively, compared to the freshwater control group(FG). Futhermore, the permeability coefficient exhibited significant increases. Subsequent microscopic analyses of the eroded grouting composites were performed. This research elucidated the erosion-weakening mechanism of grouting composites subjected to sulfate-induced degradation in complex marine environments. The study emphasizes the critical role of erosion resistance and durability in design and implementation. From practical perspective, this work establishes a foundation for developing enhanced strategies to improve the long-term performance and integrity of grouting composites in subsea tunnel applications.展开更多
In this article,we study the trajectory planning and tracking control of a bionic underwater robot under multiple dynamic obstacles.We first introduce the design of the bionic leopard cabinet underwater robot develope...In this article,we study the trajectory planning and tracking control of a bionic underwater robot under multiple dynamic obstacles.We first introduce the design of the bionic leopard cabinet underwater robot developed in our lab.Then,we model the trajectory planning problem of the bionic underwater robot by combining its dynamics and physical constraints.Furthermore,we conduct global trajectory planning for bionic underwater robots based on the temporal-spatial Bezier curves.In addition,based on the improved proximal policy optimization,local dynamic obstacle avoidance trajectory replanning is carried out.In addition,we design the fuzzy proportional-integral-derivative controller for tracking control of the planned trajectory.Finally,the effectiveness of the real-time trajectory planning and tracking control method is verified by comparative simulation in dynamic environment and semiphysical simulation of UWSim.Among them,the real-time trajectory planning method has advantages in trajectory length,trajectory smoothness,and planning time.The error of trajectory tracking control method is controlled around 0.2 m.展开更多
Considering the special features of dynamic environment economic dispatch of power systems with high dimensionality,strong coupling,nonlinearity,and non-convexity,a GA-DE multi-objective optimization algorithm based o...Considering the special features of dynamic environment economic dispatch of power systems with high dimensionality,strong coupling,nonlinearity,and non-convexity,a GA-DE multi-objective optimization algorithm based on dual-population pseudo-parallel genetic algorithm-differential evolution is proposed in this paper.The algorithm is based on external elite archive and Pareto dominance,and it adopts the cooperative co-evolution mechanism of differential evolution and genetic algorithm.Average entropy and cubic chaoticmapping initialization strategies are proposed to increase population diversity.In the proposed method,we analyze the distribution of neighboring solutions and apply a new Pareto solution set pruning approach.Unlike traditional models,this work takes the transmission losses as an optimization target and overcomes complex model constraints through a dynamic relaxation constraint approach.To solve the uncertainty caused by integrating wind and photovoltaic energy in power system scheduling,a multi-objective dynamic environment economical dispatch model is set up that takes the system spinning reserve and network highest losses into account.In this paper,the DE algorithm is improved to form the DGAGE algorithm for the objective optimization of the overall power system,The DE algorithm part of DGAGE is combined with the JAYA algorithm to form the system scheduling HDJ algorithm for multiple energy sources connected to the grid.The effectiveness of the proposed method is demonstrated using CEC2022 and CEC2005 test functions,showing robust optimization performance.Validation on a classical 10-unit system confirms the feasibility of the proposed algorithm in addressing power system scheduling issues.This approach provides a novel solution for dynamic power dispatch systems.展开更多
BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons comb...BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.展开更多
Human activities lead to the accumulation of a large amount of nitrogen and phosphorus in sediments in rivers.Simultaneously,nitrogen and phosphorus can be affected by environment and re-enter the upper water body,cau...Human activities lead to the accumulation of a large amount of nitrogen and phosphorus in sediments in rivers.Simultaneously,nitrogen and phosphorus can be affected by environment and re-enter the upper water body,causing secondary pollution of the river water.In this study,laboratory simulation experiments were conducted initially to investigate the release of nitrogen and phosphorus from river sediments in Urumqi City and the surrounding areas in Xinjiang Uygur Autonomous Region of China and determine the factors that influence their release.The results of this study showed significant short-term differences in nitrogen and phosphorus release characteristics from sediments at different sampling points.The proposed secondary kinetics model(i.e.,pseudo-second-order kinetics model)better fitted the release process of sediment nitrogen and phosphorus.The release of nitrogen and phosphorus from sediments is a complex process driven by multiple factors,therefore,we tested the influence of three factors(pH,temperature,and disturbance intensity)on the release of nitrogen and phosphorus from sediments in this study.The most amount of nitrate nitrogen(NO_(3)^(–)-N)was released under neutral conditions,while the most significant release of ammonia nitrogen(NH_(4)^(+)-N)occurred under acidic and alkaline conditions.The release of nitrite nitrogen(NO_(2)^(-)-N)was less affected by pH.The dissolved total phosphorus(DTP)released significantly in the alkaline water environment,while the release of dissolved organic phosphorus(DOP)was more significant in acidic water.The release amount of soluble reactive phosphorus(SRP)increased with an increase in pH.The sediments released nitrogen and phosphorus at higher temperatures,particularly NH_(4)^(+)-N,NO_(3)^(–)-N,and SRP.The highest amount of DOP was released at 15.0℃.An increase in disturbance intensity exacerbated the release of nitrogen and phosphorus from sediments.NH_(4)^(+)-N,DTP,and SRP levels increased linearly with the intensity of disturbance,while NO_(3)^(–)-N and NO_(2)^(–)-N were more stable.This study provides valuable information for protecting and restoring the water environment in arid areas and has significant practical reference value.展开更多
Mobile robots have been used for many industrial scenarios which can realize automated manufacturing process instead of human workers. To improve the quality of the optimal rapidly-exploring random tree(RRT^(*)) for p...Mobile robots have been used for many industrial scenarios which can realize automated manufacturing process instead of human workers. To improve the quality of the optimal rapidly-exploring random tree(RRT^(*)) for planning path in dynamic environment, a high-quality dynamic rapidly-exploring random tree(HQD-RRT^(*)) algorithm is proposed in this paper, which generates a high-quality solution with optimal path length in dynamic environment. This method proceeds in two stages: initial path generation and path re-planning. Firstly, the initial path is generated by an improved smart rapidly-exploring random tree(RRT^(*)-SMART) algorithm, and the state tree information is stored as prior knowledge. During the process of path execution, a strategy of obstacle avoidance is proposed to avoid moving obstacles. The cost and smoothness of path are considered to re-plan the initial path to improve the path quality in this strategy. Compared with related work, a higher-quality path in dynamic environment can be achieved in this paper. HQD-RRT^(*) algorithm can obtain an optimal path with better stability. Simulations on the static and dynamic environment are conducted to clarify the efficiency of HQD-RRT^(*) in avoiding unknown obstacles.展开更多
基金the National Natural Science Foundation of China(No.61671470).
文摘A great number of visual simultaneous localization and mapping(VSLAM)systems need to assume static features in the environment.However,moving objects can vastly impair the performance of a VSLAM system which relies on the static-world assumption.To cope with this challenging topic,a real-time and robust VSLAM system based on ORB-SLAM2 for dynamic environments was proposed.To reduce the influence of dynamic content,we incorporate the deep-learning-based object detection method in the visual odometry,then the dynamic object probability model is added to raise the efficiency of object detection deep neural network and enhance the real-time performance of our system.Experiment with both on the TUM and KITTI benchmark dataset,as well as in a real-world environment,the results clarify that our method can significantly reduce the tracking error or drift,enhance the robustness,accuracy and stability of the VSLAM system in dynamic scenes.
文摘While different species in nature have safely solved the problem of navigation in a dynamic environment, this remains a challenging task for researchers around the world. The paper addresses the problem of autonomous navigation in an unknown dynamic environment for a single and a group of three wheeled omnidirectional mobile robots(TWOMRs). The robot has to track a dynamic target while avoiding dynamic obstacles and dynamic walls in an unknown and very dense environment. It adopts a behavior-based controller that consists of four behaviors: "target tracking", "obstacle avoidance", "dynamic wall following" and "avoid robots". The paper considers the problem of kinematic saturation. In addition, it introduces a strategy for predicting the velocity of dynamic obstacles based on two successive measurements of the ultrasonic sensors to calculate the velocity of the obstacle expressed in the sensor frame. Furthermore, the paper proposes a strategy to deal with dynamic walls even when they have U-like or V-like shapes. The approach can also deal with the formation control of a group of robots based on the leader-follower structure and the behavior-based control, where the robots have to get together and maintain a given formation while navigating toward the target, avoiding obstacles and walls in a dynamic environment. The effectiveness of the proposed approaches is demonstrated via simulation.
基金the framework of a scientific-technical cooperation project between the Federal Institute for Geosciences and Natural Resources(BGR)and the China Geological Survey(CGS)co-funded by the German Ministry of the Economic Affairs and Energy(BMWi)and Ministry of Land and Resources of the People's Republik of China
文摘This study presents a statistical landslide susceptibility assessment(LSA) in a dynamic environment. The study area is located in the eastern part of Lanzhou, NW China. The Lanzhou area has exhibited rapid urbanization rates over the past decade associated with greening, continuous land use change, and geomorphic reshaping activities. To consider the dynamics of the environment in the LSA, multitemporal data for landslide inventories and the corresponding causal factors were collected. The weights of evidence(Wof E) method was used to perform the LSA. Three time stamps, i.e., 2000, 2012, and 2016, were selected to assess the state of landslide susceptibility over time. The results show a clear evolution of the landslide susceptibility patterns that was mainly governed by anthropogenic activities directed toward generating safer building grounds for civil infrastructure. The low and very low susceptibility areas increased by approximately 10% between 2000 and 2016. At the same time, areas of medium, high and very high susceptibility zones decreased proportionally. Based on the results, an approach to design the statistical LSA under dynamic conditions is proposed, the issues and limitations of this approach are also discussed. The study shows that under dynamic conditions, the requirements for data quantity and quality increase significantly. A dynamic environment requires greater effort to estimate the causal relations between the landslides and controlling factors as well as for model validation.
基金Supported by the National Natural Science Foundation of China(No.61100143,No.61370128)the Program for New Century Excellent Talents in University of the Ministry of Education of China(NCET-13-0659)Beijing Higher Education Young Elite Teacher Project(YETP0583)
文摘A weighted time-based global hierarchical path planning method is proposed to obtain the global optimal path from the starting point to the destination with time optimal control. First, the grid-or graph-based modeling is performed and the environment is divided into a set of grids or nodes. Then two time-based features of time interval and time cost are presented. The time intervals for each grid are built, during each interval the condition of the grid remains stable, and a time cost of passing through the grid is defined and assigned to each interval. Furthermore, the weight is introduced for taking both time and distance into consideration, and thus a sequence of multiscale paths with total time cost can be achieved. Experimental results show that the proposed method can handle the complex dynamic environment, obtain the global time optimal path and has the potential to be applied to the autonomous robot navigation and traffic environment.
基金supported by the Shenzhen Science and Technology Program(JSGG20220606142803007)the Shenzhen Institute of Artificial Intelligence and Robotics for Society(AIRS).
文摘Moving humans,agents,and subjects bring many challenges to robot self‐localisation and environment perception.To adapt to dynamic environments,SLAM researchers typically apply several deep learning image segmentation models to eliminate these moving obstacles.However,these moving obstacle segmentation methods cost too much computation resource for the onboard processing of mobile robots.In the current industrial environment,mobile robot collaboration scenario,the noise of mobile robots could be easily found by on‐board audio‐sensing processors and the direction of sound sources can be effectively acquired by sound source estimation algorithms,but the distance estimation of sound sources is difficult.However,in the field of visual perception,the 3D structure information of the scene is relatively easy to obtain,but the recognition and segmentation of moving objects is more difficult.To address these problems,a novel vision‐audio fusion method that combines sound source localisation methods with a visual SLAM scheme is proposed,thereby eliminating the effect of dynamic obstacles on multi‐agent systems.Several heterogeneous robots experiments in different dynamic scenes indicate very stable self‐localisation and environment reconstruction performance of our method.
基金supported by the National Natural Science Foundation of China (Nos.61100045,61165013,61003142,60902023,and 61171096)the China Postdoctoral Science Foundation (Nos.20090461346,201104697)+3 种基金the Youth Foundation for Humanities and Social Sciences of Ministry of Education of China (No.10YJCZH117)the Fundamental Research Funds for the Central Universities (Nos.SWJTU09CX035,SWJTU11ZT08)Zhejiang Provincial Natural Science Foundation of China (Nos.Y1100589,Y1080123)the Natural Science Foundation of Ningbo,China (No.2011A610175)
文摘Emerging technologies of wireless and mobile communication enable people to accumulate a large volume of time-stamped locations,which appear in the form of a continuous moving object trajectory.How to accurately predict the uncertain mobility of objects becomes an important and challenging problem.Existing algorithms for trajectory prediction in moving objects databases mainly focus on identifying frequent trajectory patterns,and do not take account of the effect of essential dynamic environmental factors.In this study,a general schema for predicting uncertain trajectories of moving objects with dynamic environment awareness is presented,and the key techniques in trajectory prediction arc addressed in detail.In order to accurately predict the trajectories,a trajectory prediction algorithm based on continuous time Bayesian networks（CTBNs） is improved and applied,which takes dynamic environmental factors into full consideration.Experiments conducted on synthetic trajectory data verify the effectiveness of the improved algorithm,which also guarantees the time performance as well.
基金Project(XK100070532)supported by Beijing Education Committee Cooperation Building Foundation,China
文摘To tackle the problem of simultaneous localization and mapping(SLAM) in dynamic environments, a novel algorithm using landscape theory of aggregation is presented. By exploiting the coherent explanation how actors form alignments in a game provided by the landscape theory of aggregation, the algorithm is able to explicitly deal with the ever-changing relationship between the static objects and the moving objects without any prior models of the moving objects. The effectiveness of the method has been validated by experiments in two representative dynamic environments: the campus road and the urban road.
基金Supported by the Ministerial Level Foundation(2012021)
文摘A low frequency dynamic environment prediction of spacecraft using dynamic substructu- ring is presented. The dynamic environment could be used to describe the level of the excitation on the spacecraft itself and auxiliary equipment. In addition, the dynamic environment is a criterion for the structural dynamic design as well as the ground verification test. The proposed prediction method could solve two major problems. The first is the time consumption of analyzing the whole spacecraft model due to the huge amount of degrees of freedom, and the second is multi-source for component structural dynamic models from distributive departments. To demonstrate the feasibility and efficien- cy, the proposed prediction method is applied to resolve a launching satellite case, and the results were compared with those obtained by the traditional prediction technology using the finite element method.
基金funded by "The Program on Marine Environmental Safety Guarantee" of "The National Key Research and Development Program of China"[grant number2016YFC1401409]
文摘A project entitled‘Development of a Global High-resolution Marine Dynamic Environmental Forecasting System’has been funded by‘The Program on Marine Environmental Safety Guarantee’of The National Key Research and Development Program of China.This project will accomplish its objectives through basic theoretical research,model development and expansion,and system establishment and application,with a focus on four key issues separated into nine tasks.A series of research achievements have already been obtained,including datasets,observations,theories,and model results.
文摘As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple regression to examine the relationship between corporate financial slack and R ＆ D investment under dynamic environment, using the Malmquist index method based on DEA model to analyze the innovation efficiency of Chinese manufacturing industry during the period of2009-2013. The results show that： Financial slack and R ＆ D investment intensity presents inverted ＂U＂ type relationship in？sample？companies, and the relationship is positively regulated by environmental dynamism; Financial slack promotes R ＆ D investment but have lag effect.
文摘As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple regressionto examine the relationship between corporate financial slack and R ＆ D investment under dynamic environment, using the Malmquist index method based on DEA model to analyze the innovation efficiency of Chinese manufacturing industry during the period of 2009-2013. The results show that： Financial slack and R ＆ D investment intensity presents inverted ＂U＂ type relationship in？sample？companies, and the relationship is positively regulated by environmental dynamism; Financial slackpromotes R ＆ D investment but have lag effect.
文摘In recent years, with the outbreak of epidemic infectious diseases and the increasing political and economic uncertainty, should enterprises make strategic changes in response to environmental changes in a timely manner or maintain strategic consistency under the circumstances of increasing environmental dynamics? From the perspective of contingency, this paper studies the impact of corporate strategic changes on enterprises in the context of environmental dynamics, and conducts an empirical study on manufacturing enterprises listed in A shares from 2008 to 2020. It is found that corporate strategic changes in the context of environmental dynamics are beneficial to corporate performance, but also bring financial volatility.
基金supported by the Autonomous Intelligent Unmanned Systems(No.NSFC 62088101)the National Natural Science Foundation of China(No.62306096)in part by the Zhejiang Provincial Natural Science Foundation of China under Grant(No.LD24F030001).
文摘This paper presents a visual simultaneous localization and mapping(SLAM)system designed for highly dynamic environments,capable of eliminating dynamic objects using only visual information.The proposed system integrates learning-based and geometry-based methods to address the challenges posed by moving objects.The learning-based approach leverages image segmentation to remove previously trained objects,whereas the geometry-based approach utilises point correlation to eliminate unseen objects.By complementing each other,these methods enhance the robustness of the SLAM system in dynamic sce-narios.Experimental results demonstrate that the proposed method effectively removes dynamic objects.Comparative studies with state-of-the-art algorithms further show that the proposed method achieves superior accuracy and robustness.
基金supported by the Autonomous Intelligent Unmanned Systems(No.NSFC 62088101)the National Natural Science Foundation of China(No.62306096)in part by the Zhejiang Provincial Natural Science Foundation of China under Grant(No.LD24F030001).
文摘This paper presents a visual simultaneous localization and mapping(SLAM)system designed for highly dynamic environments,capable of eliminating dynamic objects using only visual information.The proposed system integrates learning-based and geometry-based methods to address the challenges posed by moving objects.The learning-based approach leverages image segmentation to remove previously trained objects,whereas the geometry-based approach utilises point correlation to eliminate unseen objects.By complementing each other,these methods enhance the robustness of the SLAM system in dynamic scenarios.Experimental results demonstrate that the proposed method effectively removes dynamic objects.Comparative studies with state-of-the-art algorithms further show that the proposed method achieves superior accuracy and robustness.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 42477194 and 52279115)Fundamental Research Funds for the Central Universities (Grant No. 202441008)。
文摘Grouting represents a reliable method for strengthening fractured rock masses and preventing seawater infiltration in subsea tunnel engineering. However, grouting composites are continuously subjected to harsh marine environments,experiencing both chemical and physical effects from high-concentration erosive seawater ions, elevated water pressure, and complex flow fields. This multi-factor erosion deterioration diminishes the waterproofing capabilities of grouting composites and threatens the service life of subsea tunnel linings. To investigate the erosion deteriortion mechanism induced by sulfate, erosion weakening experiments were conducted using a seawater flow simulation device. The research examined the compressive strength and permeability coefficient of grouting composites under different erosion durations, water-cement ratios, and grouting pressures. In the later stages of the experiment, the strength of grouting composites in the static water erosion control group(SEG) and dynamic water erosion group(DEG) decreased by 31.2% and 18.8%, respectively, compared to the freshwater control group(FG). Futhermore, the permeability coefficient exhibited significant increases. Subsequent microscopic analyses of the eroded grouting composites were performed. This research elucidated the erosion-weakening mechanism of grouting composites subjected to sulfate-induced degradation in complex marine environments. The study emphasizes the critical role of erosion resistance and durability in design and implementation. From practical perspective, this work establishes a foundation for developing enhanced strategies to improve the long-term performance and integrity of grouting composites in subsea tunnel applications.
基金supported in part by the STI 2030-Major Projects under Grant 2021ZD0114504in part by the National Natural Science Foundation of China under Grants 62276253 and 62203435in part by the Beijing Nova Program under Grants Z211100002121152 and 20230484457.
文摘In this article,we study the trajectory planning and tracking control of a bionic underwater robot under multiple dynamic obstacles.We first introduce the design of the bionic leopard cabinet underwater robot developed in our lab.Then,we model the trajectory planning problem of the bionic underwater robot by combining its dynamics and physical constraints.Furthermore,we conduct global trajectory planning for bionic underwater robots based on the temporal-spatial Bezier curves.In addition,based on the improved proximal policy optimization,local dynamic obstacle avoidance trajectory replanning is carried out.In addition,we design the fuzzy proportional-integral-derivative controller for tracking control of the planned trajectory.Finally,the effectiveness of the real-time trajectory planning and tracking control method is verified by comparative simulation in dynamic environment and semiphysical simulation of UWSim.Among them,the real-time trajectory planning method has advantages in trajectory length,trajectory smoothness,and planning time.The error of trajectory tracking control method is controlled around 0.2 m.
基金funded by the Major Humanities and Social Sciences Research Projects in Zhejiang Higher Education Institutions,grant number 2023QN131National Innovation Training Program Project in China,grant number 202410451009.
文摘Considering the special features of dynamic environment economic dispatch of power systems with high dimensionality,strong coupling,nonlinearity,and non-convexity,a GA-DE multi-objective optimization algorithm based on dual-population pseudo-parallel genetic algorithm-differential evolution is proposed in this paper.The algorithm is based on external elite archive and Pareto dominance,and it adopts the cooperative co-evolution mechanism of differential evolution and genetic algorithm.Average entropy and cubic chaoticmapping initialization strategies are proposed to increase population diversity.In the proposed method,we analyze the distribution of neighboring solutions and apply a new Pareto solution set pruning approach.Unlike traditional models,this work takes the transmission losses as an optimization target and overcomes complex model constraints through a dynamic relaxation constraint approach.To solve the uncertainty caused by integrating wind and photovoltaic energy in power system scheduling,a multi-objective dynamic environment economical dispatch model is set up that takes the system spinning reserve and network highest losses into account.In this paper,the DE algorithm is improved to form the DGAGE algorithm for the objective optimization of the overall power system,The DE algorithm part of DGAGE is combined with the JAYA algorithm to form the system scheduling HDJ algorithm for multiple energy sources connected to the grid.The effectiveness of the proposed method is demonstrated using CEC2022 and CEC2005 test functions,showing robust optimization performance.Validation on a classical 10-unit system confirms the feasibility of the proposed algorithm in addressing power system scheduling issues.This approach provides a novel solution for dynamic power dispatch systems.
基金Supported by Hangzhou Medical and Health Technology Project,No.OO20191141。
文摘BACKGROUND Preschoolers become anxious when they are about to undergo anesthesia and surgery,warranting the development of more appropriate and effective interventions.AIM To explore the effect of static cartoons combined with dynamic virtual environments on preoperative anxiety and anesthesia induction compliance in preschool-aged children undergoing surgery.METHODS One hundred and sixteen preschool-aged children were selected and assigned to the drug(n=37),intervention(n=40),and control(n=39)groups.All the children received routine preoperative checkups and nursing before being transferred to the preoperative preparation room on the day of the operation.The drug group received 0.5 mg/kg midazolam and the intervention group treatment consisting of static cartoons combined with dynamic virtual environments.The control group received no intervention.The modified Yale Preoperative Anxiety Scale was used to evaluate the children’s anxiety level on the day before surgery(T0),before leaving the preoperative preparation room(T1),when entering the operating room(T2),and at anesthesia induction(T3).Compliance during anesthesia induction(T3)was evaluated using the Induction Compliance Checklist(ICC).Changes in mean arterial pressure(MAP),heart rate(HR),and respiratory rate(RR)were also recorded at each time point.RESULTS The anxiety scores of the three groups increased variously at T1 and T2.At T3,both the drug and intervention groups had similar anxiety scores,both of which were lower than those in the control group.At T1 and T2,MAP,HR,and RR of the three groups increased.The drug and control groups had significantly higher MAP and RR than the intervention group at T2.At T3,the MAP,HR,and RR of the drug group decreased and were significantly lower than those in the control group but were comparable to those in the intervention group.Both the drug and intervention groups had similar ICC scores and duration of anesthesia induction(T3),both of which were higher than those of the control group.CONCLUSION Combining static cartoons with dynamic virtual environments as effective as medication,specifically midazolam,in reducing preoperative anxiety and fear in preschool-aged children.This approach also improve their compliance during anesthesia induction and helped maintain their stable vital signs.
基金the Xinjiang Science and Technology Support Project Plan(2022E02026)the Xinjiang Agricultural University Graduate Research and Innovation Programme(XJAUGRI2023049).
文摘Human activities lead to the accumulation of a large amount of nitrogen and phosphorus in sediments in rivers.Simultaneously,nitrogen and phosphorus can be affected by environment and re-enter the upper water body,causing secondary pollution of the river water.In this study,laboratory simulation experiments were conducted initially to investigate the release of nitrogen and phosphorus from river sediments in Urumqi City and the surrounding areas in Xinjiang Uygur Autonomous Region of China and determine the factors that influence their release.The results of this study showed significant short-term differences in nitrogen and phosphorus release characteristics from sediments at different sampling points.The proposed secondary kinetics model(i.e.,pseudo-second-order kinetics model)better fitted the release process of sediment nitrogen and phosphorus.The release of nitrogen and phosphorus from sediments is a complex process driven by multiple factors,therefore,we tested the influence of three factors(pH,temperature,and disturbance intensity)on the release of nitrogen and phosphorus from sediments in this study.The most amount of nitrate nitrogen(NO_(3)^(–)-N)was released under neutral conditions,while the most significant release of ammonia nitrogen(NH_(4)^(+)-N)occurred under acidic and alkaline conditions.The release of nitrite nitrogen(NO_(2)^(-)-N)was less affected by pH.The dissolved total phosphorus(DTP)released significantly in the alkaline water environment,while the release of dissolved organic phosphorus(DOP)was more significant in acidic water.The release amount of soluble reactive phosphorus(SRP)increased with an increase in pH.The sediments released nitrogen and phosphorus at higher temperatures,particularly NH_(4)^(+)-N,NO_(3)^(–)-N,and SRP.The highest amount of DOP was released at 15.0℃.An increase in disturbance intensity exacerbated the release of nitrogen and phosphorus from sediments.NH_(4)^(+)-N,DTP,and SRP levels increased linearly with the intensity of disturbance,while NO_(3)^(–)-N and NO_(2)^(–)-N were more stable.This study provides valuable information for protecting and restoring the water environment in arid areas and has significant practical reference value.
基金supported by the Program for Youth Innovative Research Team in the University of Shandong Province in China(2019KJN010)。
文摘Mobile robots have been used for many industrial scenarios which can realize automated manufacturing process instead of human workers. To improve the quality of the optimal rapidly-exploring random tree(RRT^(*)) for planning path in dynamic environment, a high-quality dynamic rapidly-exploring random tree(HQD-RRT^(*)) algorithm is proposed in this paper, which generates a high-quality solution with optimal path length in dynamic environment. This method proceeds in two stages: initial path generation and path re-planning. Firstly, the initial path is generated by an improved smart rapidly-exploring random tree(RRT^(*)-SMART) algorithm, and the state tree information is stored as prior knowledge. During the process of path execution, a strategy of obstacle avoidance is proposed to avoid moving obstacles. The cost and smoothness of path are considered to re-plan the initial path to improve the path quality in this strategy. Compared with related work, a higher-quality path in dynamic environment can be achieved in this paper. HQD-RRT^(*) algorithm can obtain an optimal path with better stability. Simulations on the static and dynamic environment are conducted to clarify the efficiency of HQD-RRT^(*) in avoiding unknown obstacles.
