In this study,an adaptive neuro-observer-based optimal control(ANOPC)policy is introduced for unknown nonaffine nonlinear systems with control input constraints.Hamilton–Jacobi–Bellman(HJB)framework is employed to m...In this study,an adaptive neuro-observer-based optimal control(ANOPC)policy is introduced for unknown nonaffine nonlinear systems with control input constraints.Hamilton–Jacobi–Bellman(HJB)framework is employed to minimize a non-quadratic cost function corresponding to the constrained control input.ANOPC consists of both analytical and algebraic parts.In the analytical part,first,an observer-based neural network(NN)approximates uncertain system dynamics,and then another NN structure solves the HJB equation.In the algebraic part,the optimal control input that does not exceed the saturation bounds is generated.The weights of two NNs associated with observer and controller are simultaneously updated in an online manner.The ultimately uniformly boundedness(UUB)of all signals of the whole closed-loop system is ensured through Lyapunov’s direct method.Finally,two numerical examples are provided to confirm the effectiveness of the proposed control strategy.展开更多
求解最优潮流问题(optimal power flow, OPF)的凸松弛技术可将非凸的OPF问题转化为凸优化问题,并在精确松弛的前提下获得原问题的全局最优解。近10年来,该项技术已成为国内外电力系统优化领域的一个研究热点。首先,回顾电力系统优化领...求解最优潮流问题(optimal power flow, OPF)的凸松弛技术可将非凸的OPF问题转化为凸优化问题,并在精确松弛的前提下获得原问题的全局最优解。近10年来,该项技术已成为国内外电力系统优化领域的一个研究热点。首先,回顾电力系统优化领域凸松弛技术的发展过程,介绍半正定规划松弛、二阶锥规划松弛、二次凸包络松弛的基本概念与数学形式。接着,对于凸松弛技术的精确性,总结并梳理保证精确松弛的充分条件和构造更紧凸松弛的方法。最后,从技术手段与应用场景两个方面对OPF凸松弛技术未来的研究方向做出展望。展开更多
In this paper, the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from either an attacker or their already infected neighbors, is analyz...In this paper, the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from either an attacker or their already infected neighbors, is analyzed. Considering the Susceptible-Infected-Susceptible （SIS） node infection paradigm we propose a probabilistic model, on the basis of the theory of closed queuing networks, that aims at describing the aggregated behavior of the system when attacked by malicious nodes. Because of its nature, the model is also able to deal more effectively with the stochastic behavior of attackers and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative large scale ad hoc networking environments. Using the Norton equivalent of the closed queuing network, we obtain analytical results for its steady state behavior, which in turn is used for identifying the critical parameters affecting the operation of the network. Finally, through modeling and simulation, some additional numerical results are obtained with respect to the behavior of the system when multiple attackers are present, and regarding the time-dependent evolution and impact of an attack.展开更多
Air transport management research,concerned with all facets of aviation operations,policies,and strategies,is an essential element of making our aviation system more sustainable and preparing it for the challenges inh...Air transport management research,concerned with all facets of aviation operations,policies,and strategies,is an essential element of making our aviation system more sustainable and preparing it for the challenges inherent to the present and future.Based on a data-driven categorization of almost 2,000 papers published on the subject,we discuss the status quo in air transport management research.Through our data-driven categorization we have identified 15 broad topics.For each topic,we provide a description of the state of the art and propose 2-3 chal-lenges,respectively.Overall,our study provides a set of 35 challenges to the research community.Accordingly,we hope and believe that our study makes a valuable contribution,mainly by guiding the air transport manage-ment research community towards a delineated work plan on the research landscape of air transport as well as the present challenges,ultimately helping to improve the global air transport system.展开更多
文摘In this study,an adaptive neuro-observer-based optimal control(ANOPC)policy is introduced for unknown nonaffine nonlinear systems with control input constraints.Hamilton–Jacobi–Bellman(HJB)framework is employed to minimize a non-quadratic cost function corresponding to the constrained control input.ANOPC consists of both analytical and algebraic parts.In the analytical part,first,an observer-based neural network(NN)approximates uncertain system dynamics,and then another NN structure solves the HJB equation.In the algebraic part,the optimal control input that does not exceed the saturation bounds is generated.The weights of two NNs associated with observer and controller are simultaneously updated in an online manner.The ultimately uniformly boundedness(UUB)of all signals of the whole closed-loop system is ensured through Lyapunov’s direct method.Finally,two numerical examples are provided to confirm the effectiveness of the proposed control strategy.
文摘求解最优潮流问题(optimal power flow, OPF)的凸松弛技术可将非凸的OPF问题转化为凸优化问题,并在精确松弛的前提下获得原问题的全局最优解。近10年来,该项技术已成为国内外电力系统优化领域的一个研究热点。首先,回顾电力系统优化领域凸松弛技术的发展过程,介绍半正定规划松弛、二阶锥规划松弛、二次凸包络松弛的基本概念与数学形式。接着,对于凸松弛技术的精确性,总结并梳理保证精确松弛的充分条件和构造更紧凸松弛的方法。最后,从技术手段与应用场景两个方面对OPF凸松弛技术未来的研究方向做出展望。
基金Greek General Secretariat for Research and Technology of the Ministry of Development(PENED project under Grant No.03ED840).
文摘In this paper, the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from either an attacker or their already infected neighbors, is analyzed. Considering the Susceptible-Infected-Susceptible （SIS） node infection paradigm we propose a probabilistic model, on the basis of the theory of closed queuing networks, that aims at describing the aggregated behavior of the system when attacked by malicious nodes. Because of its nature, the model is also able to deal more effectively with the stochastic behavior of attackers and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative large scale ad hoc networking environments. Using the Norton equivalent of the closed queuing network, we obtain analytical results for its steady state behavior, which in turn is used for identifying the critical parameters affecting the operation of the network. Finally, through modeling and simulation, some additional numerical results are obtained with respect to the behavior of the system when multiple attackers are present, and regarding the time-dependent evolution and impact of an attack.
基金National Natural Science Founda-tion of China(Grant No.U2233214,No.62250710166)European Research Council(ERC)un-der the European Union’s Horizon 2020 research and innovation pro-gramme(grant agreement No 851255)+1 种基金María de Maeztu project CEX2021-001164-MMCIN/AEI/10.13039/501100011033.
文摘Air transport management research,concerned with all facets of aviation operations,policies,and strategies,is an essential element of making our aviation system more sustainable and preparing it for the challenges inherent to the present and future.Based on a data-driven categorization of almost 2,000 papers published on the subject,we discuss the status quo in air transport management research.Through our data-driven categorization we have identified 15 broad topics.For each topic,we provide a description of the state of the art and propose 2-3 chal-lenges,respectively.Overall,our study provides a set of 35 challenges to the research community.Accordingly,we hope and believe that our study makes a valuable contribution,mainly by guiding the air transport manage-ment research community towards a delineated work plan on the research landscape of air transport as well as the present challenges,ultimately helping to improve the global air transport system.
