Dynamic soaring,inspired by the wind-riding flight of birds such as albatrosses,is a biomimetic technique which leverages wind fields to enhance the endurance of unmanned aerial vehicles(UAVs).Achieving a precise soar...Dynamic soaring,inspired by the wind-riding flight of birds such as albatrosses,is a biomimetic technique which leverages wind fields to enhance the endurance of unmanned aerial vehicles(UAVs).Achieving a precise soaring trajectory is crucial for maximizing energy efficiency during flight.Existing nonlinear programming methods are heavily dependent on the choice of initial values which is hard to determine.Therefore,this paper introduces a deep reinforcement learning method based on a differentially flat model for dynamic soaring trajectory planning and optimization.Initially,the gliding trajectory is parameterized using Fourier basis functions,achieving a flexible trajectory representation with a minimal number of hyperparameters.Subsequently,the trajectory optimization problem is formulated as a dynamic interactive process of Markov decision-making.The hyperparameters of the trajectory are optimized using the Proximal Policy Optimization(PPO2)algorithm from deep reinforcement learning(DRL),reducing the strong reliance on initial value settings in the optimization process.Finally,a comparison between the proposed method and the nonlinear programming method reveals that the trajectory generated by the proposed approach is smoother while meeting the same performance requirements.Specifically,the proposed method achieves a 34%reduction in maximum thrust,a 39.4%decrease in maximum thrust difference,and a 33%reduction in maximum airspeed difference.展开更多
面向网络舆情演变过程中政府应急响应需求,本文基于SOAR（State,Operator and Result）模型,将网民作为智能体Agent,将网络舆情中网民群体行为转变过程看作相应舆情问题空间中状态随时间的连续转换过程,设计突发事件中网民群体负面情感S...面向网络舆情演变过程中政府应急响应需求,本文基于SOAR（State,Operator and Result）模型,将网民作为智能体Agent,将网络舆情中网民群体行为转变过程看作相应舆情问题空间中状态随时间的连续转换过程,设计突发事件中网民群体负面情感SOAR Agent模型,包括网民Agent的工作记忆、长期记忆、决策过程、学习机制,构建网民群体行为转换规则库和相应算法。在此基础上,设计仿真实验,结合典型网络舆情事件案例,对政府不同应急措施下微博用户群体行为演变过程进行建模。实证结果表明,基于网民群体负面情感的建模,可以分析和预测在不同网络舆情阶段、不同政府应急响应措施下网民群体的行为决策规律。展开更多
【目的/意义】面向高校网络舆情应急管理需求,以网民群体负面情感的测量作为基点,预测网络舆情演变的路径和态势,进而支持突发事件应急响应策略的制定【方法/过程】基于SOAR(State,Operator and Result)模型和情境危机传播理论,设计高...【目的/意义】面向高校网络舆情应急管理需求,以网民群体负面情感的测量作为基点,预测网络舆情演变的路径和态势,进而支持突发事件应急响应策略的制定【方法/过程】基于SOAR(State,Operator and Result)模型和情境危机传播理论,设计高校网络舆情网民群体决策模型,包括工作记忆、长期记忆、决策过程等模块。结合典型高校网络舆情案例进行建模仿真,通过真实案例数据和实验数据的对比验证模型的有效性。【结果/结论】实证结果表明,基于网民群体决策行为规则的建模,可以分析和预测在不同网络舆情阶段、不同应急响应措施下网民群体的行为决策规律,从而为高校网络舆情应急管理提出有效的方法和模型。展开更多
发生脑卒中是中老年人群的常见和多发的疾病,且具有发病比较高、致残比例高和出现死亡比例高等特点,SOAR(stroke subtype, oxfordshire community stroke project classification, age and prestroke modified rankin, mSOAR)评价得分...发生脑卒中是中老年人群的常见和多发的疾病,且具有发病比较高、致残比例高和出现死亡比例高等特点,SOAR(stroke subtype, oxfordshire community stroke project classification, age and prestroke modified rankin, mSOAR)评价得分对于国内发生急性发作的缺血性卒中(acute ischemic stroke,AIS)病人出现的不良预后风险得有着较好的预测价值。在工作中,通过总结分析AIS病人资料有关情况,登记病人年龄、牛津郡社区卒中项目(oxfordshire community stroke project,OCSP)分类别、卒中之前的改进型Rankin统计量表(modified rankin scale,mRS)评分,美国国家卫生研究院关于卒中量表(national Institutes of health stroke scale,NIHSS)评价得分等相关统计计算信息,在入院时以mSOAR统计量表开展评价得分。所有病人在出院时通过mRS工具进行评价得分,在出院时发生的死亡或重残表示为不良预后。mSOAR评价得分预判病人在出院时发生的不良预后等潜在风险的病人工作特点(receiver operating characteristic curve,ROC)的在坐标图中曲线下的所占面积范围(area under curve,AUC)的数值,mSOAR的评价表在预判AIS病人出院时出现不良预后的风险预测水平相对较高。展开更多
钙库操纵的钙内流(Store-operated Ca2+entry)是钙离子进入细胞的一种经典方式,对于多种细胞生理活动具有重要的意义.它是由位于内质网膜上的钙离子感受器STIM1分子与细胞膜上的通道蛋白ORAI1相互作用而被激活的.其中,STIM1位于细胞质内...钙库操纵的钙内流(Store-operated Ca2+entry)是钙离子进入细胞的一种经典方式,对于多种细胞生理活动具有重要的意义.它是由位于内质网膜上的钙离子感受器STIM1分子与细胞膜上的通道蛋白ORAI1相互作用而被激活的.其中,STIM1位于细胞质内的C端含有一段SOAR(STIM-ORAI association region)结构域,可以和ORAI1直接作用从而激活ORAI1组成的CRAC通道.考虑到STIM1在钙库操纵的钙内流过程中的重要调节作用,通过药物分子来调节STIM1的活性从而影响细胞、甚至机体的生理活动势必成为关注的方向.本实验将人类STIM1分子的SOAR结构域在大肠杆菌中异源表达,经过多种层析方法获得了纯度较高的SOAR蛋白,并通过与一种小分子——间苯二酚的共结晶,获得了复合物的晶体.X光衍射数据收集到0.21nm,并用HKL2000软件进行处理.这些数据为SOAR与间苯二酚复合物结构的解析奠定了基础.展开更多
安全编排、自动化与响应(Security Orchestration,Automation and SOAR)网络安全应急响应案例库建成后,当新的安全事件产生时,对相似案例进行检索,得到的案例的响应方案往往还需要经过案例修正才能运用至实际环境中。研究了SOAR网络安...安全编排、自动化与响应(Security Orchestration,Automation and SOAR)网络安全应急响应案例库建成后,当新的安全事件产生时,对相似案例进行检索,得到的案例的响应方案往往还需要经过案例修正才能运用至实际环境中。研究了SOAR网络安全应急响应案例的修正方法,提出一种基于双线规则学习的案例修正技术;并对案例修正规则学习过程中的相似案例相似性度量方法进行了研究,提出了一种基于可达矩阵的流程图相似度计算方法;然后对案例修正过程进行了描绘;最后,对提出的案例修正技术进行了实验和分析。结果表明,提出的双线规则学习模式能够用于实际安全事件的应急响应。展开更多
Harvesting wind energy is promising for extending long-endurance flights,which can be greatly facilitated by a flight technique called dynamic soaring.The presented study is concerned with generating model-based traje...Harvesting wind energy is promising for extending long-endurance flights,which can be greatly facilitated by a flight technique called dynamic soaring.The presented study is concerned with generating model-based trajectories with smooth control histories for dynamic soaring maneuvers exploiting wind gradients.The desired smoothness is achieved by introducing a trigonometric series parameterization for the controls,which are formulated with respect to the normalized time.Specifically,the periodicity of the trigonometric functions is leveraged to facilitate the connection of cycles and streamline the problem formulation.Without relying on a specified wind profile,a freefinal-time quadratic programming-based control strategy is developed for the online correction of the flight trajectory,which requires only the instant wind information.Offline and online numerical studies show the trade-off to achieve the smoothness and demonstrate the effectiveness of the proposed method in a varying wind field.展开更多
基金support received by the National Natural Science Foundation of China(Grant Nos.52372398&62003272).
文摘Dynamic soaring,inspired by the wind-riding flight of birds such as albatrosses,is a biomimetic technique which leverages wind fields to enhance the endurance of unmanned aerial vehicles(UAVs).Achieving a precise soaring trajectory is crucial for maximizing energy efficiency during flight.Existing nonlinear programming methods are heavily dependent on the choice of initial values which is hard to determine.Therefore,this paper introduces a deep reinforcement learning method based on a differentially flat model for dynamic soaring trajectory planning and optimization.Initially,the gliding trajectory is parameterized using Fourier basis functions,achieving a flexible trajectory representation with a minimal number of hyperparameters.Subsequently,the trajectory optimization problem is formulated as a dynamic interactive process of Markov decision-making.The hyperparameters of the trajectory are optimized using the Proximal Policy Optimization(PPO2)algorithm from deep reinforcement learning(DRL),reducing the strong reliance on initial value settings in the optimization process.Finally,a comparison between the proposed method and the nonlinear programming method reveals that the trajectory generated by the proposed approach is smoother while meeting the same performance requirements.Specifically,the proposed method achieves a 34%reduction in maximum thrust,a 39.4%decrease in maximum thrust difference,and a 33%reduction in maximum airspeed difference.
文摘面向网络舆情演变过程中政府应急响应需求,本文基于SOAR（State,Operator and Result）模型,将网民作为智能体Agent,将网络舆情中网民群体行为转变过程看作相应舆情问题空间中状态随时间的连续转换过程,设计突发事件中网民群体负面情感SOAR Agent模型,包括网民Agent的工作记忆、长期记忆、决策过程、学习机制,构建网民群体行为转换规则库和相应算法。在此基础上,设计仿真实验,结合典型网络舆情事件案例,对政府不同应急措施下微博用户群体行为演变过程进行建模。实证结果表明,基于网民群体负面情感的建模,可以分析和预测在不同网络舆情阶段、不同政府应急响应措施下网民群体的行为决策规律。
文摘【目的/意义】面向高校网络舆情应急管理需求,以网民群体负面情感的测量作为基点,预测网络舆情演变的路径和态势,进而支持突发事件应急响应策略的制定【方法/过程】基于SOAR(State,Operator and Result)模型和情境危机传播理论,设计高校网络舆情网民群体决策模型,包括工作记忆、长期记忆、决策过程等模块。结合典型高校网络舆情案例进行建模仿真,通过真实案例数据和实验数据的对比验证模型的有效性。【结果/结论】实证结果表明,基于网民群体决策行为规则的建模,可以分析和预测在不同网络舆情阶段、不同应急响应措施下网民群体的行为决策规律,从而为高校网络舆情应急管理提出有效的方法和模型。
文摘发生脑卒中是中老年人群的常见和多发的疾病,且具有发病比较高、致残比例高和出现死亡比例高等特点,SOAR(stroke subtype, oxfordshire community stroke project classification, age and prestroke modified rankin, mSOAR)评价得分对于国内发生急性发作的缺血性卒中(acute ischemic stroke,AIS)病人出现的不良预后风险得有着较好的预测价值。在工作中,通过总结分析AIS病人资料有关情况,登记病人年龄、牛津郡社区卒中项目(oxfordshire community stroke project,OCSP)分类别、卒中之前的改进型Rankin统计量表(modified rankin scale,mRS)评分,美国国家卫生研究院关于卒中量表(national Institutes of health stroke scale,NIHSS)评价得分等相关统计计算信息,在入院时以mSOAR统计量表开展评价得分。所有病人在出院时通过mRS工具进行评价得分,在出院时发生的死亡或重残表示为不良预后。mSOAR评价得分预判病人在出院时发生的不良预后等潜在风险的病人工作特点(receiver operating characteristic curve,ROC)的在坐标图中曲线下的所占面积范围(area under curve,AUC)的数值,mSOAR的评价表在预判AIS病人出院时出现不良预后的风险预测水平相对较高。
文摘钙库操纵的钙内流(Store-operated Ca2+entry)是钙离子进入细胞的一种经典方式,对于多种细胞生理活动具有重要的意义.它是由位于内质网膜上的钙离子感受器STIM1分子与细胞膜上的通道蛋白ORAI1相互作用而被激活的.其中,STIM1位于细胞质内的C端含有一段SOAR(STIM-ORAI association region)结构域,可以和ORAI1直接作用从而激活ORAI1组成的CRAC通道.考虑到STIM1在钙库操纵的钙内流过程中的重要调节作用,通过药物分子来调节STIM1的活性从而影响细胞、甚至机体的生理活动势必成为关注的方向.本实验将人类STIM1分子的SOAR结构域在大肠杆菌中异源表达,经过多种层析方法获得了纯度较高的SOAR蛋白,并通过与一种小分子——间苯二酚的共结晶,获得了复合物的晶体.X光衍射数据收集到0.21nm,并用HKL2000软件进行处理.这些数据为SOAR与间苯二酚复合物结构的解析奠定了基础.
文摘安全编排、自动化与响应(Security Orchestration,Automation and SOAR)网络安全应急响应案例库建成后,当新的安全事件产生时,对相似案例进行检索,得到的案例的响应方案往往还需要经过案例修正才能运用至实际环境中。研究了SOAR网络安全应急响应案例的修正方法,提出一种基于双线规则学习的案例修正技术;并对案例修正规则学习过程中的相似案例相似性度量方法进行了研究,提出了一种基于可达矩阵的流程图相似度计算方法;然后对案例修正过程进行了描绘;最后,对提出的案例修正技术进行了实验和分析。结果表明,提出的双线规则学习模式能够用于实际安全事件的应急响应。
基金supported in part by the TUM University Foundation Fellowshipin part by the German Federal Ministry for Economic Affairs and Energy(BMWi)within the Federal Aeronautical Research Program LuFo VI-1through Project“RAUDY”(No.20E1910B)。
文摘Harvesting wind energy is promising for extending long-endurance flights,which can be greatly facilitated by a flight technique called dynamic soaring.The presented study is concerned with generating model-based trajectories with smooth control histories for dynamic soaring maneuvers exploiting wind gradients.The desired smoothness is achieved by introducing a trigonometric series parameterization for the controls,which are formulated with respect to the normalized time.Specifically,the periodicity of the trigonometric functions is leveraged to facilitate the connection of cycles and streamline the problem formulation.Without relying on a specified wind profile,a freefinal-time quadratic programming-based control strategy is developed for the online correction of the flight trajectory,which requires only the instant wind information.Offline and online numerical studies show the trade-off to achieve the smoothness and demonstrate the effectiveness of the proposed method in a varying wind field.
