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空间电子技术 1993年第4期 6-14页

作者： lewis,gc 何贤洋

Guaranteed Cost Attitude Tracking Control for Uncertain Quadrotor Unmanned Aerial Vehicle Under Safety Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1447-1457页

作者： Qian Ma Peng Jin Frank L.lewis School of Automation Nanjing University of Science and TechnologyNanjing 210094China UTA Research Institute University of Texas at ArlingtonFort WorthTexas 76118 USA IEEE

In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is ***,an augmented system is constructed by the tracking error system and reference *** transformation aims to convert the tracking control prob-lem into a stabilization control ***,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty *** on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is ***,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal *** proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety *** performance of the algorithm is evaluated by the numerical simulation.

关键词： Attitude tracking control quadrotor unmanned aerial vehicle(QUAV) reinforcement learning safety constraints uncertain disturbances.

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Error-based adaptive optimal tracking control of nonlinear discrete-time systems

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Science China(Information Sciences) 2024年第1期67卷 154-167页

作者： Chun LI Jinliang DING Frank L.lewis Tianyou CHAI State Key Laboratory of Synthetical Automation for Process Industries Northeastern University UTA Research Institute The University of Texas at Arlington

In this paper,for the output tracking problem of nonlinear discrete-time systems,a performance index is newly defined using the adaptive dynamic programming(ADP) technique to completely eliminate tracking errors in *** contrast to traditional definitions of performance indices in other ADP-based methods,the proposed performance index is not only designed from the perspective of output tracking errors but also introduced errors of system states and control inputs at adjacent stages,which is suitable for practical situations in many industrial applications,such as the alumina production,the flotation process,and the mineral grinding *** proved that the obtained controller can make the system output fully track the given reference trajectory by applying the iterative criteria of the ADP *** addition,the proposed algorithm was implemented using a data-driven technique and neural networks to avoid analyzing and deducing the complicated dynamics of actual industrial ***,using historical data for a forced-circulation evaporation system in the alumina production process,the effect of the proposed approach was verified through a numerical simulation and compared with that of the proportional-integral controller.

关键词： adaptive dynamic programming iterative criteria performance index tracking errors tracking problem

Control Policy Learning Design for Vehicle Urban Positioning via BeiDou Navigation

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Journal of Systems Science & Complexity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengli lewis Frank L School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China. Center for Intelligent Batch Manufacturing Based on IoT Technology Key Laboratory of Intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint Laboratory for Smart Discrete Manufacturing Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou *** navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou ***,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback *** proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle *** is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation multipath effect prescribed convergence rate reinforcement learning urban localization.

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Recent Progress in Reinforcement Learning and Adaptive Dynamic Programming for Advanced Control Applications

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 18-36页

作者： Ding Wang Ning Gao Derong Liu Jinna Li Frank L.lewis IEEE the Faculty of Information Technology Beijing Key Laboratory of Computational Intelligence and Intelligent SystemBeijing Laboratory of Smart Environmental Protectionand Beijing Institute of Artificial IntelligenceBeijing University of TechnologyBeijing 100124China the School of System Design and Intelligent Manufacturing Southern University of Science and TechnologyShenzhen 518055China the Department of Electrical and Computer Engineering University of Illinois at ChicagoChicago IL 60607 USA the School of Information and Control Engineering Liaoning Petrochemical UniversityFushun 113001China the UTA Research Institute the University of Texas at ArlingtonArlington TX 76118 USA

Reinforcement learning(RL) has roots in dynamic programming and it is called adaptive/approximate dynamic programming(ADP) within the control community. This paper reviews recent developments in ADP along with RL and its applications to various advanced control fields. First, the background of the development of ADP is described, emphasizing the significance of regulation and tracking control problems. Some effective offline and online algorithms for ADP/adaptive critic control are displayed, where the main results towards discrete-time systems and continuous-time systems are surveyed, ***, the research progress on adaptive critic control based on the event-triggered framework and under uncertain environment is discussed, respectively, where event-based design, robust stabilization, and game design are reviewed. Moreover, the extensions of ADP for addressing control problems under complex environment attract enormous attention. The ADP architecture is revisited under the perspective of data-driven and RL frameworks,showing how they promote ADP formulation ***, several typical control applications with respect to RL and ADP are summarized, particularly in the fields of wastewater treatment processes and power systems, followed by some general prospects for future research. Overall, the comprehensive survey on ADP and RL for advanced control applications has d emonstrated its remarkable potential within the artificial intelligence era. In addition, it also plays a vital role in promoting environmental protection and industrial intelligence.

关键词： Adaptive dynamic programming(ADP) advanced control complex environment data-driven control event-triggered design intelligent control neural networks nonlinear systems optimal control reinforcement learning(RL)

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Bimetallic reduced graphene oxide/zeolitic imidazolate framework hybrid aerogels for efficient heavy metals removal

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 49-66页

作者： Nurul A.Mazlan Allana lewis Fraz Saeed Butt Rajakumari Krishnamoorthi Siyu Chen Yi Huang School of Engineering Institute for Materials&ProcessesThe University of EdinburghEdinburgh EH93FBUK

Graphene oxide is a promising adsorption ***,it has been difficult to recycle and separate graphene oxide in the *** alleviate this problem,graphene oxide was thermally reduced to produce porous hydrogel which was then functionalized with *** functional groups act as not only adsorption sites but also nucleation sites for in situ crystallization of cobalt-doped zeolitic-imidazolate-framework-8 *** effects of cobalt-doping contents on the physicochemical and adsorption properties of the resulting aerogel were also evaluated by varying the cobalt *** instance,the reduced graphene oxide-polydopamine/50cobalt-zeolitic-imidazolate-framework-8 aerogel exhibited a high surface area of 900 m^(2)·g^(-1)and maintained the structure in water after ten *** as-synthesized aerogels showed an ultrahigh adsorption capacity of 1217±24.35 mg·g^(-1)with a removal efficiency of>99%of lead,as well as excellent adsorption performance toward other heavy metals,such as copper and cadmium with adsorption capacity of 1163±34.91 and 1059±31.77 mg·g^(-1),*** importantly,the lead adsorption stabilized at 1023±20.5 mg·g^(-1)with a removal efficiency of>80%after seven cycles,indicating their potential in heavy metal removal from industrial wastewater.

关键词： rGO Co-doped ZIF-8 heavy metals adsorption aerogel

Out-of-Equilibrium Assembly Based on Host-Guest Interactions

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CCS Chemistry 2024年第1期6卷 27-40页

作者： Guotai Li Reece W.lewis Rienk Eelkema School of Rehabilitation Sciences and Engineering University of Health and Rehabilitation SciencesQingdao 266071 Department of Chemical Engineering Delft University of Technology2629 HZ Delft

The field of supramolecular chemistry is rapidly progressing,transitioning from the creation of thermodynamically stable systems found in local or global minima on the free energy landscape to the development of out-of-equilibrium systems that rely on chemical reactions to establish and maintain their *** the past decade,numerous artificial out-of-equilibrium systems have been devised in various domains of supramolecular chemistry,many of which have been extensively ***,one area that has received limited attention thus far is the use of out-of-equilibrium processes to regulate host-guest *** minireview aims to address this gap by exploring the construction of out-ofequilibrium systems based on host-guest complexation,which likely employs similar strategies to those employed in analogous noncovalent *** review begins with a summary of these shared ***,it discusses representative publications that exemplify these strategies and classifies thembased onwhich component is being modulated-host,guest,or competitive *** this examination,our objective is to shed light on the design of out-of-equilibrium systems relying on host-guest interactions and provide valuable insights into the preparation strategies for various transient materials.

关键词： out-of-equilibrium host-guest chemistry self-assembly supramolecular materials chemical fuel

Novel photoactive material and fabrication techniques for solar cells application:nanocellulose-based graphene oxide CdS composite

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Clean Energy 2024年第2期8卷 189-216页

作者： Hassan Oriyomi Shoyiga Stephen Okiemute Akpasi Joseph Akpan Ubani Oluwaseun Amune Sammy lewis Kiambi Chemistry Department North-West UniversityMafikengSouth Africa Material Science Innovation and Modelling(MaSIM)Research Focus Area Faculty of Natural and Agricultural SciencesNorth-West University(Mafikeng Campus)MmabathoSouth Africa Green Engineering Research Group Chemical Engineering DepartmentDurban University of TechnologyDurbanSouth Africa Industrial Engineering Department Durban University of TechnologyDurbanSouth Africa Chemical Engineering Department Edo State UniversityUzairueNigeria Chemical Engineering Department Vaal University of TechnologyVanderbijlparkSouth Africa

In recent times,solar energy has become one of the largest available sources of renewable energy at our ***,the design of highly efficient solar cells is increasingly becoming crucial as there has been a surge for economically viable alternative energy sources with the lowest *** advances have been made through different routes to make photovoltaic(PV)/solar technologies economically viable,eco-friendly and consequently *** a result,cellulose nanomaterials have become one of the emerging technologies in this regard because of the advantages of high-value bio-based nanostructured materials,such as their abundance and ***-based photoactive nanocomposite materials can be made by integrating conducting photoactive and electroconductive materials with hydrophilic biocompatible *** nanoparticles,such as graphene/reduced graphene oxide cadmium sulphide quantum dots,amongst others,can be introduced into the nanocellulose matrix and can be applied either as charge transporters or photoactive materials in different types of solar ***,in this review,we highlight the optoelectronic properties of different photoactive materials,particularly nanocellulose-based graphene nanocomposites;their efficiencies and drawbacks were *** effect of doping each PV material on the PV performance is also *** is anticipated that the novel material would result in a reduction in the cost of solar cells,jointly enhancing their efficacy in generating environmentally friendly *** the fabrication techniques and equipment play a crucial role in the development of solar cells,the fabrication techniques of bulk-heterojunction(BHJ)cells containing a nanocellulose-based graphene composite and case studies of already fabricated BHJ PV cells with nanocellulose-based graphene composite are discussed.

关键词： nanocellulose-based composite bulk heterojunction graphene composite photoactive materials fabrication techniques solar energy power conversion efficiency

Improving the hydrostability of zeolitic imidazolate framework coatings using a facile silk fibroin protein modification method

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Nano Research 2024年第7期17卷 6247-6257页

作者： Xiuming Wei Ting Chen Siyu Chen Qian Jia Nurul Ain Mazlan Allana lewis Norbert Radacsi Yi Huang School of Engineering Institute for Materials&ProcessesThe University of EdinburghRobert Stevenson RoadEdinburghEH93FBUK EASTCHEM School of Chemistry The University of St AndrewsPurdie BuildingNorth HaughSt AndrewsKY169STUK

Zeolitic imidazolate frameworks(ZIFs)are an important subclass of metal-organic frameworks(MOFs)with zeolite-type topology,which can be fabricated under ambient synthesis ***,the applications of ZIFs are commonly limited due to the weak hydrostability of their metal–ligand coordination bonds,particularly under humid and aqueous *** this work,as an example,the hydrolysis behaviours of ZIF-L with a special focus on ZIF-L coatings were tested at aqueous conditions with a wide range of pHs to systematically study and fundamentally understand their structural stability and degradation *** ZIF-L powder and ZIF-L coatings were severely damaged after only 24 h in aqueous ***,the ZIF-L coatings showed two distinct hydrolyzation pathways regardless of pH conditions,exhibiting either a ring-shaped etching or unfolding *** the ZIF-L powders were hydrolyzed almost identically across all pH *** this new understanding,a facile silk fibroin(SF)protein modification method was developed to enhance the hydrostability of ZIF-L coatings in aqueous *** effect of protein concentration on surface coating was systemically ***-L coating retained its surface morphology after soaking in water and demonstrated switchable super wetting properties and superior separation performance for oil/water *** a result,the quick SF protein modification significantly enhanced the stability of ZIF-L coatings under various pHs,while retaining their switchable wetting property and excellent separation performance.

关键词： zeolitic imidazole framework-L(ZIF-L) ZIF-L coatings silk fibroin protein hydrostability enhancement oil/water separation

The GBR Hypothesis Revisited

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Journal of High Energy Physics, Gravitation and Cosmology 2024年第2期10卷 800-809页

作者： lewis Nash Marrietta GA USA

The radical hypothesis concerning the physics of gravitational black-body radiation is placed on a more solid statistical mechanics foundation in this study. As the concepts and formalism in the former presentation are only partially developed and furthermore, suffer from an unfortunate misstep regarding Hawking radiation and the hypothetical gravitational black-body temperature of a parcel or distribution of energy;this paper aims to fill in some of the theoretical gaps in the derivation of the Planck radiation formula for gravity (or non-Euclidean space-time), and there by provide a more complete and transparent quantum theory of thermal gravitational radiation.

关键词： Gravitational Black Body Gravitons Thermal Gravitational Radiation Spiral Galaxy Rotation Curves