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The role of forest culture in green construction and management of forest parks:merging knowledge-attitude-practice and theory of planned behavior 被引量:1
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作者 Yao Xu Zhiguang Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第3期841-852,共12页
As a cultural concept refl ecting the relationship between humans and forests,forest culture plays an active role in sustainable forest management.Forest parks provide a wide range of ecosystem services essential for ... As a cultural concept refl ecting the relationship between humans and forests,forest culture plays an active role in sustainable forest management.Forest parks provide a wide range of ecosystem services essential for the sustainable development of society,and the relationships between forest culture,green construction and management of forest parks have practical signifi cance.This study aimed to understand the interaction and process of forest culture infl uencing green construction and management in forest parks with the models Knowledge-Attitude-Practice(KAP)and Theory of Planned Behavior(TPB)by proposing a theoretical model.Four hypotheses were tested using data collected from 193 forest park employees in Heilongjiang Province,China.Our results show that forest culture had a signifi cant infl uence on green construction and forest management.In addition,subjective norm and perceived behavioral control directly impacted behavior in green construction and management of the forest park,whereas attitude did not have an impact.Subjective norm had a direct eff ect on attitude.Results between constructs show that forest culture had an indirect eff ect on planning and construction,and on ecological and economic management.Consequently,it supported three of four hypotheses within the proposed model in determining the infl uence of forest culture on green construction and management. 展开更多
关键词 Forest parks Forest culture Green construction and management Knowledge-attitudepractice Theory of planned behavior
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8 large coal-fired generating units planned to be commissioned in Shandong Power Grid in 1997
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《Electricity》 1997年第2期51-52,共2页
关键词 GRID large coal-fired generating units planned to be commissioned in Shandong Power Grid in 1997
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Creating the Role of Rural Teachers as New Rural Sages under the Background of Rural Revitalization Based on Organizational Change and Planned Happenstance Theories
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作者 LIN Jiangfeng YANG Shuai SHAN Yingyu 《Journal of Landscape Research》 2023年第6期65-68,72,共5页
In the context of rural revitalization,people are re-examining the issue of creating the role of teachers as“new rural sages”.However,most of previous studies ignored the school organizational change in the process ... In the context of rural revitalization,people are re-examining the issue of creating the role of teachers as“new rural sages”.However,most of previous studies ignored the school organizational change in the process of reform.The planned happenstance suggests that teachers should maintain a positive mindset about the eventualities in their careers.Based on the organizational change theory,this paper gave some advice to help teachers in playing a role of new rural sages:①rooting in local culture and enhancing teachers’sense of belonging,②providing compensation for teachers in a targeted way,and③providing a comprehensive and objective evaluation mechanism for ensuring teachers’participation in social governance. 展开更多
关键词 Rural teacher School organizational reform planned happenstance theory New rural sage
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Exploration moving beyond medical facility walls:opportunities,challenges and attitudes of midwives towards planned homebirth:a qualitative
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作者 Thuraya Ibrahim Ahmad Fallatah Grace Mcfarlane Lindsay 《Nursing Communications》 2023年第18期1-8,共8页
Background:The establishment of Saudi Vision 2030 has led to a shift from obstetric care to midwifery-led care in maternity care,giving rise to planned home birth(PHB).This study may enable midwives to carry out PHB a... Background:The establishment of Saudi Vision 2030 has led to a shift from obstetric care to midwifery-led care in maternity care,giving rise to planned home birth(PHB).This study may enable midwives to carry out PHB and achieve the goals of the Saudi health vision.The general aim is to explore Saudi midwives’attitudes towards the PHB,opportunities and challenges associated with PHB implementation in Saudi Arabia.Methods:We employed a qualitative study design and conducted interviews using open-ended questions with 19 Saudi midwives recruited from thirteen health regions.Thematic analysis was manually performed to analyze the qualitative data.Results:Thematic analysis revealed seven major themes:midwives as care providers in PHB,health institutions,academic institutions,national policy for PHB,Women’s health status,socio-economic and physical environment suitability,and maternal and neonatal health outcomes.However,Saudi midwives would exhibit a favorable attitude towards PHB if decision-makers from the Ministry of Health and the Ministry of Education addressed the challenges and promoted opportunities for providers,organizations,and the population.Conclusion:The findings of the thematic analysis shed light on several positive aspects,including job opportunities and high financial incomes for midwives.However,they also revealed challenges such as a shortage of midwifery staff,a scarcity of midwifery academic programs,and an ineffective administrative support system for midwives.Integrating both sets of findings enhances the understanding of the challenges and opportunities of planned home birth in Saudi Arabia from various perspectives,capturing the breadth and depth of the obtained data. 展开更多
关键词 planned home birth thematic analysis maternal services midwife Saudi Arabia
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Moving beyond medical facility walls:opportunities,challenges and attitudes of midwives towards planned homebirth
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作者 Thuraya Ibrahim Ahmad Fallatah Grace M.Lindsay Roa F.Altaweli 《History & Philosophy of Medicine》 2023年第3期1-7,共7页
Background/Aims:The Saudi Vision 2030 program has introduced midwifery-led maternity care in Saudi Arabia,which includes facilitating planned home births.This study aimed to investigate Saudi midwives’attitudes to pl... Background/Aims:The Saudi Vision 2030 program has introduced midwifery-led maternity care in Saudi Arabia,which includes facilitating planned home births.This study aimed to investigate Saudi midwives’attitudes to planned home birth and the opportunities and challenges associated with its implementation.Methods:The study used a descriptive cross-sectional quantitative study design,including all hospitals of the Saudi Ministry of Health and primary healthcare centers in Saudi Arabia.Data were collected concurrently from 301 midwives through the provider attitude toward planned home birth questionnaire.Descriptive analysis and inferential statistical analyses were used for quantitative data.Results:The midwives had a neutral attitude to planned home birth.There were significant differences in attitude according to age,education and health region.Seven major themes emerged:midwives as care providers,health institutions,academic institutions,national policy,women’s health,the socioeconomic and physical environment and maternal and neonatal health outcomes.Conclusion:Saudi midwives are likely to have a favorable attitude to planned home births if the Ministry of Health and Ministry of Education decision-makers eliminate the associated challenges and promote opportunities for providers,organizations and the population. 展开更多
关键词 maternity services MIDWIFE planned homebirth Saudi Arabia
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Disentangling the effects of management and climate change on habitat suitability for saproxylic species in boreal forests
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作者 Ellinoora Ekman María Triviño +3 位作者 Clemens Blattert Adriano Mazziotta Maria Potterf Kyle Eyvindson 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期121-133,共13页
Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests.Intensive forest management and high-end climate emission sc... Forest degradation induced by intensive forest management and temperature increase by climate change are resulting in biodiversity decline in boreal forests.Intensive forest management and high-end climate emission scenarios can further reduce the amount and diversity of deadwood,the limiting factor for habitats for saproxylic species in European boreal forests.The magnitude of their combined effects and how changes in forest management can affect deadwood diversity under a range of climate change scenarios are poorly understood.We used forest growth simulations to evaluate how forest management and climate change will individually and jointly affect habitats of red-listed saproxylic species in Finland.We simulated seven forest management regimes and three climate scenarios(reference,RCP4.5 and RCP8.5)over 100 years.Management regimes included set aside,continuous cover forestry,business-as-usual(BAU)and four modifications of BAU.Habitat suitability was assessed using a speciesspecific habitat suitability index,including 21 fungal and invertebrate species groups.“Winner”and“loser”species were identified based on the modelled impacts of forest management and climate change on their habitat suitability.We found that forest management had a major impact on habitat suitability of saproxylic species compared to climate change.Habitat suitability index varied by over 250%among management regimes,while overall change in habitat suitability index caused by climate change was on average only 2%.More species groups were identified as winners than losers from impacts of climate change(52%–95%were winners,depending on the climate change scenario and management regime).The largest increase in habitat suitability index was achieved under set aside(254%)and the climate scenario RCP8.5(>2%),while continuous cover forestry was the most suitable regime to increase habitat suitability of saproxylic species(up to+11%)across all climate change scenarios.Our results show that close-to-nature management regimes(e.g.,continuous cover forestry and set aside)can increase the habitat suitability of many saproxylic boreal species more than the basic business-as-usual regime.This suggests that biodiversity loss of many saproxylic species in boreal forests can be mitigated through improved forest management practices,even as climate change progresses. 展开更多
关键词 BIODIVERSITY Simulations FINLAND Forest planning Habitat suitability DEADWOOD
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Optimal search path planning of UUV in battlefeld ambush scene
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作者 Wei Feng Yan Ma +3 位作者 Heng Li Haixiao Liu Xiangyao Meng Mo Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期541-552,共12页
Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean current.Firstly,by establishing these mathematical ... Aiming at the practical application of Unmanned Underwater Vehicle(UUV)in underwater combat,this paper proposes a battlefield ambush scene with UUV considering ocean current.Firstly,by establishing these mathematical models of ocean current environment,target movement,and sonar detection,the probability calculation methods of single UUV searching target and multiple UUV cooperatively searching target are given respectively.Then,based on the Hybrid Quantum-behaved Particle Swarm Optimization(HQPSO)algorithm,the path with the highest target search probability is found.Finally,through simulation calculations,the influence of different UUV parameters and target parameters on the target search probability is analyzed,and the minimum number of UUVs that need to be deployed to complete the ambush task is demonstrated,and the optimal search path scheme is obtained.The method proposed in this paper provides a theoretical basis for the practical application of UUV in the future combat. 展开更多
关键词 Battlefield ambush Optimal search path planning UUV path Planning Probability of cooperative search
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Safe Motion Planning and Control Framework for Automated Vehicles with Zonotopic TRMPC
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作者 Hao Zheng Yinong Li +1 位作者 Ling Zheng Ehsan Hashemi 《Engineering》 SCIE EI CAS CSCD 2024年第2期146-159,共14页
Model mismatches can cause multi-dimensional uncertainties for the receding horizon control strategies of automated vehicles(AVs).The uncertainties may lead to potentially hazardous behaviors when the AV tracks ideal ... Model mismatches can cause multi-dimensional uncertainties for the receding horizon control strategies of automated vehicles(AVs).The uncertainties may lead to potentially hazardous behaviors when the AV tracks ideal trajectories that are individually optimized by the AV's planning layer.To address this issue,this study proposes a safe motion planning and control(SMPAC)framework for AVs.For the control layer,a dynamic model including multi-dimensional uncertainties is established.A zonotopic tube-based robust model predictive control scheme is proposed to constrain the uncertain system in a bounded minimum robust positive invariant set.A flexible tube with varying cross-sections is constructed to reduce the controller conservatism.For the planning layer,a concept of safety sets,representing the geometric boundaries of the ego vehicle and obstacles under uncertainties,is proposed.The safety sets provide the basis for the subsequent evaluation and ranking of the generated trajectories.An efficient collision avoidance algorithm decides the desired trajectory through the intersection detection of the safety sets between the ego vehicle and obstacles.A numerical simulation and hardware-in-the-loop experiment validate the effectiveness and real-time performance of the SMPAC.The result of two driving scenarios indicates that the SMPAC can guarantee the safety of automated driving under multi-dimensional uncertainties. 展开更多
关键词 Automated vehicles Automated driving Motion planning Motion control Tube MPC ZONOTOPE
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A Planning Method for Operational Test of UAV Swarm Based on Mission Reliability
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作者 Jingyu Wang Ping Jiang Jianjun Qi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1889-1918,共30页
The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the... The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the high cost and long duration of operational tests,it is essential to plan the test in advance.To solve the problem of planning UAV swarm operational test,this study considers the multi-stage feature of a UAV swarm mission,composed of launch,flight and combat stages,and proposes a method to find test plans that can maximize mission reliability.Therefore,a multi-stage mission reliability model for a UAV swarm is proposed to ensure successful implementation of the mission.A multi-objective integer optimization method that considers both mission reliability and cost is then formulated to obtain the optimal test plans.This study first constructs a mission reliability model for the UAV swarm in the combat stage.Then,the launch stage and flight stage are integrated to develop a complete PMS(Phased Mission Systems)reliability model.Finally,the Binary Decision Diagrams(BDD)and Multi Objective Quantum Particle Swarm Optimization(MOQPSO)methods are proposed to solve the model.The optimal plans considering both reliability and cost are obtained.The proposed model supports the planning of UAV swarm operational tests and represents a meaningful exploration of UAV swarm test planning. 展开更多
关键词 UAV swarm PMS MOQPSO BDD mission reliability operational test planning
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Ground threat prediction-based path planning of unmanned autonomous helicopter using hybrid enhanced artificial bee colony algorithm
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作者 Zengliang Han Mou Chen +1 位作者 Haojie Zhu Qingxian Wu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期1-22,共22页
Unmanned autonomous helicopter(UAH)path planning problem is an important component of the UAH mission planning system.Aiming to reduce the influence of non-complete ground threat information on UAH path planning,a gro... Unmanned autonomous helicopter(UAH)path planning problem is an important component of the UAH mission planning system.Aiming to reduce the influence of non-complete ground threat information on UAH path planning,a ground threat prediction-based path planning method is proposed based on artificial bee colony(ABC)algorithm by collaborative thinking strategy.Firstly,a dynamic threat distribution probability model is developed based on the characteristics of typical ground threats.The dynamic no-fly zone of the UAH is simulated and established by calculating the distribution probability of ground threats in real time.Then,a dynamic path planning method for UAH is designed in complex environment based on the real-time prediction of ground threats.By adding the collision warning mechanism to the path planning model,the flight path could be dynamically adjusted according to changing no-fly zones.Furthermore,a hybrid enhanced ABC algorithm is proposed based on collaborative thinking strategy.The proposed algorithm applies the leader-member thinking mechanism to guide the direction of population evolution,and reduces the negative impact of local optimal solutions caused by collaborative learning update strategy,which makes the optimization performance of ABC algorithm more controllable and efficient.Finally,simulation results verify the feasibility and effectiveness of the proposed ground threat prediction path planning method. 展开更多
关键词 UAH Path planning Ground threat prediction Hybrid enhanced Collaborative thinking
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Evolutionary Decision-Making and Planning for Autonomous Driving Based on Safe and Rational Exploration and Exploitation
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作者 Kang Yuan Yanjun Huang +4 位作者 Shuo Yang Zewei Zhou Yulei Wang Dongpu Cao Hong Chen 《Engineering》 SCIE EI CAS CSCD 2024年第2期108-120,共13页
Decision-making and motion planning are extremely important in autonomous driving to ensure safe driving in a real-world environment.This study proposes an online evolutionary decision-making and motion planning frame... Decision-making and motion planning are extremely important in autonomous driving to ensure safe driving in a real-world environment.This study proposes an online evolutionary decision-making and motion planning framework for autonomous driving based on a hybrid data-and model-driven method.First,a data-driven decision-making module based on deep reinforcement learning(DRL)is developed to pursue a rational driving performance as much as possible.Then,model predictive control(MPC)is employed to execute both longitudinal and lateral motion planning tasks.Multiple constraints are defined according to the vehicle’s physical limit to meet the driving task requirements.Finally,two principles of safety and rationality for the self-evolution of autonomous driving are proposed.A motion envelope is established and embedded into a rational exploration and exploitation scheme,which filters out unreasonable experiences by masking unsafe actions so as to collect high-quality training data for the DRL agent.Experiments with a high-fidelity vehicle model and MATLAB/Simulink co-simulation environment are conducted,and the results show that the proposed online-evolution framework is able to generate safer,more rational,and more efficient driving action in a real-world environment. 展开更多
关键词 Autonomous driving DECISION-MAKING Motion planning Deep reinforcement learning Model predictive control
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Stochastic programming based coordinated expansion planning of generation,transmission,demand side resources,and energy storage considering the DC transmission system
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作者 Liang Lu Mingkui Wei +4 位作者 Yuxuan Tao Qing Wang Yuxiao Yang Chuan He Haonan Zhang 《Global Energy Interconnection》 EI CSCD 2024年第1期25-37,共13页
With the increasing penetration of wind and solar energies,the accompanying uncertainty that propagates in the system places higher requirements on the expansion planning of power systems.A source-grid-load-storage co... With the increasing penetration of wind and solar energies,the accompanying uncertainty that propagates in the system places higher requirements on the expansion planning of power systems.A source-grid-load-storage coordinated expansion planning model based on stochastic programming was proposed to suppress the impact of wind and solar energy fluctuations.Multiple types of system components,including demand response service entities,converter stations,DC transmission systems,cascade hydropower stations,and other traditional components,have been extensively modeled.Moreover,energy storage systems are considered to improve the accommodation level of renewable energy and alleviate the influence of intermittence.Demand-response service entities from the load side are used to reduce and move the demand during peak load periods.The uncertainties in wind,solar energy,and loads were simulated using stochastic programming.Finally,the effectiveness of the proposed model is verified through numerical simulations. 展开更多
关键词 Hydro-wind-solar complementary Expansion planning Demand response Energy storage system Source-network-demand-storage coordination
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A Reverse Path Planning Approach for Enhanced Performance of Multi-Degree-of-Freedom Industrial Manipulators
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作者 Zhiwei Lin Hui Wang +3 位作者 Tianding Chen Yingtao Jiang Jianmei Jiang Yingpin Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1357-1379,共23页
In the domain of autonomous industrial manipulators,precise positioning and appropriate posture selection in path planning are pivotal for tasks involving obstacle avoidance,such as handling,heat sealing,and stacking.... In the domain of autonomous industrial manipulators,precise positioning and appropriate posture selection in path planning are pivotal for tasks involving obstacle avoidance,such as handling,heat sealing,and stacking.While Multi-Degree-of-Freedom(MDOF)manipulators offer kinematic redundancy,aiding in the derivation of optimal inverse kinematic solutions to meet position and posture requisites,their path planning entails intricate multiobjective optimization,encompassing path,posture,and joint motion optimization.Achieving satisfactory results in practical scenarios remains challenging.In response,this study introduces a novel Reverse Path Planning(RPP)methodology tailored for industrial manipulators.The approach commences by conceptualizing the manipulator’s end-effector as an agent within a reinforcement learning(RL)framework,wherein the state space,action set,and reward function are precisely defined to expedite the search for an initial collision-free path.To enhance convergence speed,the Q-learning algorithm in RL is augmented with Dyna-Q.Additionally,we formulate the cylindrical bounding box of the manipulator based on its Denavit-Hartenberg(DH)parameters and propose a swift collision detection technique.Furthermore,the motion performance of the end-effector is refined through a bidirectional search,and joint weighting coefficients are introduced to mitigate motion in high-power joints.The efficacy of the proposed RPP methodology is rigorously examined through extensive simulations conducted on a six-degree-of-freedom(6-DOF)manipulator encountering two distinct obstacle configurations and target positions.Experimental results substantiate that the RPP method adeptly orchestrates the computation of the shortest collision-free path while adhering to specific posture constraints at the target point.Moreover,itminimizes both posture angle deviations and joint motion,showcasing its prowess in enhancing the operational performance of MDOF industrial manipulators. 展开更多
关键词 Reverse path planning Dyna-Q bidirectional search posture angle joint motion
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General Optimal Trajectory Planning:Enabling Autonomous Vehicles with the Principle of Least Action
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作者 Heye Huang Yicong Liu +4 位作者 Jinxin Liu Qisong Yang Jianqiang Wang David Abbink Arkady Zgonnikov 《Engineering》 SCIE EI CAS CSCD 2024年第2期63-76,共14页
This study presents a general optimal trajectory planning(GOTP)framework for autonomous vehicles(AVs)that can effectively avoid obstacles and guide AVs to complete driving tasks safely and efficiently.Firstly,we emplo... This study presents a general optimal trajectory planning(GOTP)framework for autonomous vehicles(AVs)that can effectively avoid obstacles and guide AVs to complete driving tasks safely and efficiently.Firstly,we employ the fifth-order Bezier curve to generate and smooth the reference path along the road centerline.Cartesian coordinates are then transformed to achieve the curvature continuity of the generated curve.Considering the road constraints and vehicle dynamics,limited polynomial candidate trajectories are generated and smoothed in a curvilinear coordinate system.Furthermore,in selecting the optimal trajectory,we develop a unified and auto-tune objective function based on the principle of least action by employing AVs to simulate drivers’behavior and summarizing their manipulation characteristics of“seeking benefits and avoiding losses.”Finally,by integrating the idea of receding-horizon optimization,the proposed framework is achieved by considering dynamic multi-performance objectives and selecting trajectories that satisfy feasibility,optimality,and adaptability.Extensive simulations and experiments are performed,and the results demonstrate the framework’s feasibility and effectiveness,which avoids both dynamic and static obstacles and applies to various scenarios with multi-source interactive traffic participants.Moreover,we prove that the proposed method can guarantee real-time planning and safety requirements compared to drivers’manipulation. 展开更多
关键词 Autonomous vehicle Trajectory planning Multi-performance objectives Principle of least action
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Research on Anthropomorphic Obstacle Avoidance Trajectory Planning for Adaptive Driving Scenarios Based on Inverse Reinforcement Learning Theory
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作者 Jian Wu Yang Yan +1 位作者 Yulong Liu Yahui Liu 《Engineering》 SCIE EI CAS CSCD 2024年第2期133-145,共13页
The forward design of trajectory planning strategies requires preset trajectory optimization functions,resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajecto... The forward design of trajectory planning strategies requires preset trajectory optimization functions,resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajectories that conform to real driver behavior habits.In addition,owing to the strong time-varying dynamic characteristics of obstacle avoidance scenarios,it is necessary to design numerous trajectory optimization functions and adjust the corresponding parameters.Therefore,an anthropomorphic obstacle-avoidance trajectory planning strategy for adaptive driving scenarios is proposed.First,numerous expert-demonstrated trajectories are extracted from the HighD natural driving dataset.Subsequently,a trajectory expectation feature-matching algorithm is proposed that uses maximum entropy inverse reinforcement learning theory to learn the extracted expert-demonstrated trajectories and achieve automatic acquisition of the optimization function of the expert-demonstrated trajectory.Furthermore,a mapping model is constructed by combining the key driving scenario information that affects vehicle obstacle avoidance with the weight of the optimization function,and an anthropomorphic obstacle avoidance trajectory planning strategy for adaptive driving scenarios is proposed.Finally,the proposed strategy is verified based on real driving scenarios.The results show that the strategy can adjust the weight distribution of the trajectory optimization function in real time according to the“emergency degree”of obstacle avoidance and the state of the vehicle.Moreover,this strategy can generate anthropomorphic trajectories that are similar to expert-demonstrated trajectories,effectively improving the adaptability and acceptability of trajectories in driving scenarios. 展开更多
关键词 Obstacle avoidance trajectory planning Inverse reinforcement theory Anthropomorphic Adaptive driving scenarios
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Multi-UAVs Collaborative Path Planning in the Cramped Environment
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作者 Siyuan Feng Linzhi Zeng +2 位作者 Jining Liu Yi Yang Wenjie Song 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第2期529-538,共10页
Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. Howe... Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. However, safe and effective path planning of multiple unmanned aerial vehicles(UAVs)in the cramped environment is always challenging: conflicts with each other are frequent because of high-density flight paths, collision probability increases because of space constraints, and the search space increases significantly, including time scale, 3D scale and model scale. Thus, this paper proposes a hierarchical collaborative planning framework with a conflict avoidance module at the high level and a path generation module at the low level. The enhanced conflict-base search(ECBS) in our framework is improved to handle the conflicts in the global path planning and avoid the occurrence of local deadlock. And both the collision and kinematic models of UAVs are considered to improve path smoothness and flight safety. Moreover, we specifically designed and published the cramped environment test set containing various unique obstacles to evaluating our framework performance thoroughly. Experiments are carried out relying on Rviz, with multiple flight missions: random, opposite, and staggered, which showed that the proposed method can generate smooth cooperative paths without conflict for at least 60 UAVs in a few minutes.The benchmark and source code are released in https://github.com/inin-xingtian/multi-UAVs-path-planner. 展开更多
关键词 Collision avoidance conflict resolution multi-unmanned aerial vehicles(UAVs)system path planning
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Cooperative UAV search strategy based on DMPC-AACO algorithm in restricted communication scenarios
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作者 Shiyuan Chai Zhen Yang +3 位作者 Jichuan Huang Xiaoyang Li Yiyang Zhao Deyun Zhou 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期295-311,共17页
Improvement of integrated battlefield situational awareness in complex environments involving dynamic factors such as restricted communications and electromagnetic interference(EMI)has become a contentious research pr... Improvement of integrated battlefield situational awareness in complex environments involving dynamic factors such as restricted communications and electromagnetic interference(EMI)has become a contentious research problem.In certain mission environments,due to the impact of many interference sources on real-time communication or mission requirements such as the need to implement communication regulations,the mission stages are represented as a dynamic combination of several communication-available and communication-unavailable stages.Furthermore,the data interaction between unmanned aerial vehicles(UAVs)can only be performed in specific communication-available stages.Traditional cooperative search algorithms cannot handle such situations well.To solve this problem,this study constructed a distributed model predictive control(DMPC)architecture for a collaborative control of UAVs and used the Voronoi diagram generation method to re-plan the search areas of all UAVs in real time to avoid repetition of search areas and UAV collisions while improving the search efficiency and safety factor.An attention mechanism ant-colony optimization(AACO)algorithm is proposed for UAV search-control decision planning.The search strategy is adaptively updated by introducing an attention mechanism for regular instruction information,a priori information,and emergent information of the mission to satisfy different search expectations to the maximum extent.Simulation results show that the proposed algorithm achieves better search performance than traditional algorithms in restricted communication constraint scenarios. 展开更多
关键词 Unmanned aerial vehicles(UAV) Cooperative search Restricted communication Mission planning DMPC-AACO
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Adaptive Space Expansion for Fast Motion Planning
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作者 Shenglei Shi Jiankui Chen 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1499-1514,共16页
The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning space.In this paper,we pro-pose an adaptive space expansion(ASE)approac... The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning space.In this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible path.The ASE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary space.Specifically,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is expanded.Thus,the ASE method successively does space exploring and space expan-sion until the final path has been found.Besides,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in it.At last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE strategy.Simulations demon-strate that the computation speed is much faster than that of the state-of-the-art algorithms.The source codes are available at https://github.com/shshlei/ompl. 展开更多
关键词 Adaptive space expansion(ASE) hyper-ellipsoid ring informed sampling motion planning.
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An integrated spatial planning of the mountainous landscapes for ski sports in a case area at the eastern Türkiye
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作者 SATIR Onur TOSUN Busra +2 位作者 COSKUN OZYOL Funda OZDEMIR Omer Faruk BERBEROGLU Suha 《Journal of Mountain Science》 SCIE CSCD 2024年第3期754-767,共14页
Mountainous regions have disadvantages in economic development because of harsh physical and climatic conditions.However,winter tourism activities are one of the key components for supporting economic development in t... Mountainous regions have disadvantages in economic development because of harsh physical and climatic conditions.However,winter tourism activities are one of the key components for supporting economic development in the highlands.Establishing a ski resort area supports direct and indirect employment in a region,and it stops immigration from mountainous regions to other places.This research aimed to assess the potential ski areas using a multi criteria evaluation technique in the Van region which is located in the eastern part of Türkiye.In this context,snow cover duration,sun effect,slope,slope length,elevation,population density,distance from main roads and lake visibility were used as input factors in the decision making process.Each factor was standardized using a fuzzy technique based on existing well-known ski centers in Türkiye.The weight of inputs was defined by applying a survey to the professional skiers.The most important factors were detected as transportation opportunities and snow covers whereas,the least important factors were elevation and population density.Additionally,lake visibility was very important to make a difference from other existing facilities in the region.Therefore,it was included as constraints and lake visible areas were extracted at the final stage of the research.Potential ski areas were mapped in three levels as professional,intermediate and beginner skiers.One of the suitable areas was selected as a sample projection and for the 3D simulation of the ski investment area.Potential costs and benefits were discussed.It was found that a ski tourism area investment can be amortized in 3 years in the region. 展开更多
关键词 Winter sports and tourism Decision making 3D simulation and modelling Landscape planning GIS
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Research on Evacuation Path Planning Based on Improved Sparrow Search Algorithm
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作者 Xiaoge Wei Yuming Zhang +2 位作者 Huaitao Song Hengjie Qin Guanjun Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1295-1316,共22页
Reducing casualties and property losses through effective evacuation route planning has been a key focus for researchers in recent years.As part of this effort,an enhanced sparrow search algorithm(MSSA)was proposed.Fi... Reducing casualties and property losses through effective evacuation route planning has been a key focus for researchers in recent years.As part of this effort,an enhanced sparrow search algorithm(MSSA)was proposed.Firstly,the Golden Sine algorithm and a nonlinear weight factor optimization strategy were added in the discoverer position update stage of the SSA algorithm.Secondly,the Cauchy-Gaussian perturbation was applied to the optimal position of the SSA algorithm to improve its ability to jump out of local optima.Finally,the local search mechanism based on the mountain climbing method was incorporated into the local search stage of the SSA algorithm,improving its local search ability.To evaluate the effectiveness of the proposed algorithm,the Whale Algorithm,Gray Wolf Algorithm,Improved Gray Wolf Algorithm,Sparrow Search Algorithm,and MSSA Algorithm were employed to solve various test functions.The accuracy and convergence speed of each algorithm were then compared and analyzed.The results indicate that the MSSA algorithm has superior solving ability and stability compared to other algorithms.To further validate the enhanced algorithm’s capabilities for path planning,evacuation experiments were conducted using different maps featuring various obstacle types.Additionally,a multi-exit evacuation scenario was constructed according to the actual building environment of a teaching building.Both the sparrow search algorithm and MSSA algorithm were employed in the simulation experiment for multiexit evacuation path planning.The findings demonstrate that the MSSA algorithm outperforms the comparison algorithm,showcasing its greater advantages and higher application potential. 展开更多
关键词 Sparrow search algorithm optimization and improvement function test set evacuation path planning
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