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Control Policy learning Design for Vehicle Urban Positioning via BeiDou Navigation

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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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

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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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Experimental and numerical investigation to elucidate the fluid flow through packed beds with structured particle packings

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Particuology 2024年第6期89卷 218-237页

作者： Shirin Patil Christian Gorges Joel lòpez Bonilla Moritz Stelter frank Beyrau Berend van Wachem laboratory of Technical Thermodynamics Otto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany Chair of Mechanical Process Engineering Otto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany

The present paper presents an experimental and numerical investigation of the dispersion of the gaseous jet flow and co-flow for the simple unit cell(SUC)and body-centred cubic(BCC)configuration of particles in packed *** experimental setup is built in such a way that suitable and simplified boundary conditions are imposed for the corresponding numerical framework,so the simulations can be done under very similar conditions as the ***,a porous plate is used for the co-flow to achieve the uniform velocity and the fully developed flow is ensured for the jet *** SUC and BCC particle beds consist of 3D-printed spheres,and the non-isotropy near the walls is mostly eliminated by placing half-spheres at the channel *** flow velocities are analysed directly at the exit of the particle bed for both beds over 36 pores for the SUC configuration and 60 pores for the BCC configuration,for particle Reynolds numbers of 200,300,and *** particle image velocimetry is experimentally arranged in such a way that the velocities over the entire region at the exit of the packed bed are obtained *** numerical method consists of a state-of-the-art immersed boundary method with adaptive mesh *** paper presents the pore jet structure and velocity field exiting from each pore for the SUC and BCC packed particle *** numerical and experimental studies show a good agreement for the SUC configuration for all flow *** the BCC configuration,some differences can be observed in the pore jet flow structure between the simulations and the experiments,but the general flow velocity distribution shows a good overall *** axial velocity is generally higher for the pores located near the centre of the packed bed than for the pores near the *** addition,the axial velocities are observed to increase near the peripheral pores of the packed *** behaviour is predominant for the BCC configuration as compared to t

关键词： Uniform particle packing Packed bed reactor Stereo particle image velocimetry Immersed boundary method

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胰岛素对昆虫病原线虫生长发育、生殖力及致病力的影响

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中国生物防治学报 2024年第4期 856-865页

作者：钱秀娟孙丹臧建成 Edwin E.lewis 甘肃农业大学植物保护学院/甘肃省农作物病虫害生物防治工程实验室西藏农牧学院植物科学学院美国爱达荷大学农业与生命科学学院昆虫学植物病理学及线虫学系

昆虫病原线虫是一种极具潜力的生防因子，因其高效的杀虫特性而受到国际生防界的广泛关注，胰岛素作为一种蛋白质多肽，已被证实对昆虫、线虫等的生长发育、寿命均有重要调控作用。为了明确胰岛素对昆虫病原线虫的影响，本试验通过对经... 详细信息

昆虫病原线虫是一种极具潜力的生防因子，因其高效的杀虫特性而受到国际生防界的广泛关注，胰岛素作为一种蛋白质多肽，已被证实对昆虫、线虫等的生长发育、寿命均有重要调控作用。为了明确胰岛素对昆虫病原线虫的影响，本试验通过对经卡森斯氏线虫Steinernemakraussei0657l和短尾异小杆线虫Heterorhabditisbrevicaudis0641TY侵染的大蜡螟Galleriamellonella注射不同浓度胰岛素，观测昆虫病原线虫的生活史及其对大蜡螟的致病力，以明确胰岛素对昆虫病原线虫生长发育、生殖力、致病力的影响。结果表明：胰岛素干预时间和干预浓度均可对卡森斯氏线虫0657l在寄主昆虫体内的生长发育产生影响，侵染当天（t）干预和高浓度（1:500）干预，会明显缩短其发育历期；侵染当天无论是高浓度还是低浓度的胰岛素干预，均会明显缩短短尾异小杆线虫0641TY的发育历期，且相比较卡森斯氏线虫0657l，胰岛素促进短尾异小杆线虫0641TY发育历期的效果更明显。在卡森斯氏线虫0657l侵染大蜡螟10 d后，注射低浓度的胰岛素，可显著提高其生殖力；在短尾异小杆线虫0641TY侵染大蜡螟1d后，注射低浓度的胰岛素，可显著提高其生殖力。胰岛素对卡森斯氏线虫0657l致病力有影响，在24 h内高浓度胰岛素可显著缩短寄主昆虫的死亡时间，但是侵染36 h后，各处理间差异不显著；而对短尾异小杆线虫0641TY致病力无影响。综上所述，胰岛素对卡森斯氏线虫0657l和短尾异小杆线虫0641TY的发育和生殖力均有影响，且对卡森斯氏线虫致病力有影响。

关键词：胰岛素昆虫病原线虫生长发育生殖力致病力

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Graphene-calcium carbonate coating to improve the degradation resistance and mechanical integrity of a biodegradable implant

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Journal of Magnesium and Alloys 2024年第1期12卷 394-404页

作者： lokesh Choudhary Parama Chakraborty Banerjee R.K.Singh Raman Derrek E.lobo Christopher D.Easton Mainak Majumder frank Witte Jörg F.löffler Department of Mechanical and Aerospace Engineering Monash UniversityClayton CampusMelbourneVIC 3800Australia Department of Chemical and Biological Engineering Monash UniversityClayton CampusMelbourneVIC 3800Australia Nanoscale Science and Engineering laboratory(NSEl) Bldg 37Monash UniversityClayton CampusMelbourneVIC 3800Australia CSIRO Materials Science and Engineering Bayview AvenueClaytonVIC 3168Australia Julius Wolff Institute and Berlin Brandenburg Center for Regenerative Therapies Charité–Universitätsmedizin BerlinAugustenburger Platz 113353 BerlinGermany laboratory of Metal Physics and Technology Department of MaterialsETH Zurich8093 ZurichSwitzerland

Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body *** necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical *** this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(RGO)-calcium carbonate(CaCO_(3))composite *** analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field.

关键词： Graphene coating Biodegradable implant Hydroxyapatite Corrosion Magnesium alloy

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Retrospective study of the incidence, risk factors, treatment outcomes of bacterial infections at uncommon sites in cirrhotic patients

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World Journal of Hepatology 2024年第3期16卷 418-427页

作者： Sophie Schneitler Christina Schneider Markus Casper frank lammert Marcin Krawczyk Sören l Becker Matthias Christian Reichert Institute of Medical Microbiology and Hygiene Saarland UniversityHomburg 66421Germany Department of Medicine II Saarland University Medical CenterHomburg 66421Germany Health Sciences Hannover Medical SchoolHannover 30625Germany laboratory of Metabolic liver Diseases Department of GeneralTransplant and Liver SurgeryCentre for Preclinical ResearchMedical University of WarsawWarsaw 02-097Poland

BACKGROUND Bacterial infections(BI)negatively affect the natural course of *** most frequent BI are urinary tract infections(UTI),pneumonia,and spontaneousbacterial peritonitis(SBP).AIM To assess the relevance of bacterial infections beyond the commonly recognized types in patients with cirrhosis and to investigate their relationship with other clinical *** We retrospectively analyzed patients with cirrhosis and BI treated between 2015 and 2018 at our tertiary care *** were classified as typical and atypical,and clinical as well as laboratory parameters were compared between the two *** In a cohort of 488 patients with cirrhosis,we identified 225 typical BI(95 UTI,73 SBP,72 pulmonary infections)and 74 atypical BIs,predominantly cholangitis and soft tissue infections(21 each),followed by intra-abdominal BIs(n=9),cholecystitis(n=6),head/throat BIs(n=6),osteoarticular BIs(n=5),and endocarditis(n=3).We did not observe differences concerning age,sex,or etiology of cirrhosis in patients with typical vs atypical *** BIs were more common in patients with more advanced cirrhosis,as evidenced by Model of End Stage liver Disease(15.1±7.4 vs 12.9±5.1;P=0.005)and Child-Pugh scores(8.6±2.5 vs 8.0±2;P=0.05).CONClUSION Atypical BIs in cirrhosis patients exhibit a distinct spectrum and are associated with more advanced stages of the ***,the work-up of cirrhosis patients with suspected BI requires detailed work-up to elucidate whether typical BI can be identified.

关键词： Bacterial infection Empirical antibiotic therapy End-stage liver disease Escherichia coli Multi-resistant pathogens

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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

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Improving the radiological diagnosis of hepatic artery thrombosis after liver transplantation: Current approaches and future challenges

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World Journal of Transplantation 2024年第1期14卷 1-8页

作者： Cristian lindner Raúl Riquelme Rodrigo San Martín frank Quezada Jorge Valenzuela Juan P Maureira Martín Einersen Department of Radiology Faculty of MedicineUniversity of ConcepciónConcepción 4030000Chile Department of Radiology Hospital Clínico Regional Guillermo Grant BenaventeConcepción 4030000Chile Department of Statistics Catholic University of MauleTalca 3460000Chile Neurovascular Unit Department of RadiologyHospital Clínico Regional Guillermo Grant BenaventeConcepción 4030000Chile

Hepatic artery thrombosis(HAT)is a devastating vascular complication following liver transplantation,requiring prompt diagnosis and rapid revascularization treatment to prevent graft *** present,imaging modalities such as ultrasound,computed tomography,and magnetic resonance play crucial roles in diagnosing *** imaging techniques have improved sensitivity and specificity for HAT diagnosis,they have limitations that hinder the timely diagnosis of this *** this sense,the emergence of artificial intelligence(AI)presents a transformative opportunity to address these diagnostic *** development of machine learning algorithms and deep neural networks has demonstrated the potential to enhance the precision diagnosis of liver transplant complications,enabling quicker and more accurate detection of *** article examines the current landscape of imaging diagnostic techniques for HAT and explores the emerging role of AI in addressing future challenges in the diagnosis of HAT after liver transplant.

关键词： liver transplantation Postoperative complications Hepatic artery Thrombosis Radiology Artificial intelligence

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