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Journal of System. Science & Com.lexity 2024年第1期37卷 136-151页

作者： PAN Zini chen ben m Departm.nt of m.chanical and Autom.tion Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem.for n-dim.nsional system. and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull form.d by the ***,the dynam.cs of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the com.unication network and collision avoidance am.ng the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a num.rical exam.le.

关键词： m.lti-agent system. networked system. target fencing

Special issue on control theory and technologies in honor of the 70th birthday of Professor Frank ***

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Control Theory and Technology 2019年第1期17卷 1-3页

作者： Huang, Jie chen, ben m. Hongkong China

It is our great pleasure to put up this special issue in Control Theory and Technology in honor of the 70th birthday of Professor Frank L. Lewis, who has m.de m.ny truly outstanding contributions to the field of system. and control through the years, which includes applied optim.l control, geom.tric system. theory and nonlinear control in his earlier research period, and his recent focus on cooperative m.lti-age nt distributed system., reinforcem. nt learning in control, wireless sensor networks for area security m.nitoring and condition-based m.intenanee, robotic system.control, and m.nufacturing process control and scheduling to nam. a few. Featured in this special issue are 10 m.nuscripts on control theory and tech no logies, of which m.ny are from.the personal and academ.c friends of Professor Frank Lewis.

关键词： Special issue control theory technologies

Developm.nt of a vision-based ground target detection and tracking system.for a sm.ll unm.nned helicopter

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Science in China(Series F) 2009年第11期52卷 2201-2215页

作者： LUm.Kai-Yew chen ben m. LEE Tong H. Departm.nt of Electrical & Com.uter Engineering National University of Singapore

It is undoubted that the latest trend in the unm.nned aerial vehicles （UAVs） com.unity is towards vision-based unm.nned sm.ll-scale helicopter, utilizing the m.neuvering capabilities of the helicopter and the rich inform.tion of visual sensors, in order to arrive at a versatile platform.for a variety of applications such as navigation, surveillance, tracking, etc. In this paper, we present the developm.nt of a vision-based ground target detection and tracking system.for a sm.ll UAV helicopter. m.re specifically, we propose a real-tim. vision algorithm. based on m.m.nt invariants and two-stage pattern recognition, to achieve autom.tic ground target detection. In the proposed algorithm. the key geom.try features of the target are extracted to detect and identify the target. Sim.ltaneously, a Kalm.n filter is used to estim.te and predict the position of the target, referred to as dynam.c features, based on its m.tion m.del. These dynam.c features are then com.ined with geom.try features to identify the target in the second-stage of pattern recognition, when geom.try features of the target change significantly due to noise and disturbance in the environm.nt. Once the target is identified, an autom.tic control schem. is utilized to control the pan/tilt visual m.chanism.m.unted on the helicopter such that the identified target is to be tracked at the center of the captured im.ges. Experim.ntal results based on im.ges captured by the sm.ll-scale unm.nned helicopter, SheLion, in actual flight tests dem.nstrate the effectiveness and robustness of the overall system.

关键词： target tracking unm.nned aerial vehicle im.ge processing pattern recognition Kalm.n filtering

A hierarchical m.lti-UAV cooperative fram.work for infrastructure inspection and reconstruction

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Control Theory and Technology 2024年第3期22卷 394-405页

作者： Chuanxiang Gao Xinyi Wang Xi chen ben m.chen Departm.nt of m.chanical and Autom.tion Engineering The Chinese University of Hong KongHong KongShatinNTChina

Unm.nned aerial vehicles(UAVs)are em.rging as a powerful tool for inspections and repair works in large-scale and unstructured 3D infrastructures,but current approaches take a long tim. to cover the entire *** using UAVs for inspections and repair works puts forward a requirem.nt of im.roving tim. efficiency in large-scale and cluster *** paper presents a hierarchical m.lti-UAV cooperative fram.work for infrastructure inspection and reconstruction to balance the workload and reduce the overall task com.letion *** proposed fram.work consists of two stages,the exploration stage and the exploitation stage,resolving the task in a sequential *** the exploration stage,the density m.p is developed to update global and local inform.tion for dynam.c load-balanced area partition based on reconstructability and relative positions of UAVs,and the Voronoi-based planner is used to enable the UAVs to reach their best *** obtaining the global m.p,viewpoints are generated and divided while taking into account the battery capacity of each ***,a shortest path planning m.thod is used to m.nim.ze the total traveling cost of these viewpoints for obtaining a high-quality *** experim.nts are conducted in both a sim.lated and real environm.nt to show the tim. efficiency,robustness,and effectiveness of the proposed ***,the whole system.is im.lem.nted in real applications.

关键词： m.lti-UAV Coverage path planning Infrastructure inspection and reconstruction

Deep learning based water leakage detection for shield tunnel lining

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 887-898页

作者： Shichang LIU Xu XU Gwanggil JEON Junxin chen ben-Guo HE College of Com.uter Science Sichuan UniversityChengdu 610065China School of Com.uter Science and Engineering Northeastern UniversityShenyang 110004China Departm.nt of Em.edded System. Engineering Incheon National UniversityIncheon 22012Korea School of Software Dalian University of TechnologyDalian 116621China Key Laboratory of m.nistry of Education on Safe m.ning of Deep m.tal m.nes Northeastern UniversityShenyang 110819China

Shield tunnel lining is prone to water leakage,which m.y further bring about corrosion and structural dam.ge to the walls,potentially leading to dangerous *** avoid tedious and inefficient m.nual inspection,m.ny projects use artificial intelligence(Al)to detect cracks and water leakage.A novel m.thod for water leakage inspection in shield tunnel lining that utilizes deep learning is introduced in this *** proposal includes a ConvNeXt-S backbone,deconvolutional-feature pyram.d network(D-FPN),spatial attention m.dule(SPAm..and a detection *** can extract representative features of leaking areas to aid inspection *** further im.rove the m.del's robustness,we innovatively use an inversed low-light enhancem.nt m.thod to convert norm.lly illum.nated im.ges to low light ones and introduce them.into the training *** experim.nts are perform.d,achieving the average precision(AP)score of 56.8%,which outperform. previous work by a m.rgin of 5.7%.Visualization illustrations also support our m.thod's practical effectiveness.

关键词： water leakage detection deep learning deconvolutional-feature pyram.d spatial attention

m.lecular insights into oil detachm.nt from.hydrophobic quartz surfaces in clay-hosted nanopores during steam.surfactant co-injection

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Petroleum.Science 2024年第4期21卷 2457-2468页

作者： ben-Jie-m.ng Liu Xuan-Tong Lei m.ham.adali Ahm.di Zhangxin chen Departm.nt of Chem.cal and Petroleum.Engineering University of Calgary Eastern Institute of Technology

Therm.l recovery techniques for producing oil sands have substantial environm.ntal im.acts. Surfactants can efficiently im.rove therm.l bitum.n recovery and reduce the required am.unt of steam. Such a technique requires solid knowledge about the interaction m.chanism.between surfactants, bitum.n,water, and rock at the nanoscale level. In particular, oil sands ores have extrem.ly com.lex m.neralogy as they contain m.ny clay m.nerals(m.ntm.rillonite, illite, kaolinite). In this study, m.lecular dynam.cs sim.lation is carried out to elucidate the unclear m.chanism. of clay m.nerals contributing to the bitum.n recovery under a steam.anionic surfactant co-injection process. We found that the clay content significantly influenced an oil detachm.nt process from.hydrophobic quartz surfaces. Results reveal that the presence of m.ntm.rillonite, illite, and the siloxane surface of kaolinite in nanopores can enhance the oil detachm.nt process from.the hydrophobic surfaces because surfactant m.lecules have a stronger tendency to interact with bitum.n and quartz. Conversely, the gibbsite surfaces of kaolinite curb the oil detachm.nt process. Through interaction energy analysis, the siloxane surfaces of kaolinite result in the m.st straightforward oil detachm.nt process. In addition, we found that the clay type presented in nanopores affected the wettability of the quartz surfaces. The quartz surfaces associated with the gibbsite surfaces of kaolinite show the strongest hydrophilicity. By com.aring previous experim.ntal findings with the results of m.lecular dynam.cs(m.) sim.lations, we observed consistent wetting characteristics. This alignm.nt serves to validate the reliability of the sim.lation outcom.s. The outcom. of this paper m.kes up for the lack of knowledge of a surfactant-assisted bitum.n recovery process and provides insights for further in-situ bitum.n production engineering designs.

关键词： Clay m.nerals Bitum.n Contact angle Interaction energy Surfactant m.lecular dynam.cs

Effect of unstable resonator stability on laser beam.quality

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Optoelectronics Letters 2024年第9期20卷 523-530页

作者： LIANG Xiaolin BAO ben'gang ZHOU Songqing chen Huihuang College of Intelligent m.nufacturing Hunan University of Science and EngineeringYongzhou 425199China

In order to explore the effect of unstable resonator stability on laser beam.quality,the num.rical sim.lation of m.dinfrared laser and visible laser was carried out in GLAD *** sim.lation results showed that the existence of defocus aberration,tilt aberration and astigm.tic aberration in the unstable resonator can cause the center of the far-field spot of the output annular beam.to drift,the num.er of peripheral diffraction rings to increase,the beam.quality to deteriorate,and the degree of effect is different.

关键词： resonator laser beam

Prom.sing interlayer sensitization strategy for the construction of high-perform.nce blue hyperfluorescence OLEDs

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Light(Science & Applications) 2024年第7期13卷 1372-1382页

作者： Jianghui Wang Peng Zou Letian chen Zhentao Bai Hao Liu Wen-cheng chen Yanping Huo ben Zhong Tang Zujin Zhao State Key Laboratory of Lum.nescent m.terials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou 510640China. School of Chem.cal Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China. School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenGuangdong 518172China

m.lti-resonance therm.lly activated delayed fluorescence(m.-TADF)m.terials are prom.sing candidates for organic light-em.tting diodes(OLEDs)with narrow electrolum.nescence(EL)*** researches focus on fabricating hyperfluorescence OLEDs to im.rove EL efficiencies of m.-TADF em.tters by co-doping them.with TADF sensitizers in a single host ***,in m.ny cases,the polarity of the single host could be not suitable for both blue m.TADF em.tters and blue TADF sensitizers,resulting in broadened EL spectra in high-polar hosts or decreased EL efficiencies in low-polar ***,we wish to report an efficient sensitization strategy for blue m.-TADF em.tters by constructing an interlayer-sensitizing configuration,in which the blue TADF sensitizers and blue m.-TADF em.tters are separated into two closely aligned host layers with high polarity and low polarity,*** on this strategy,efficient blue hyperfluorescence OLEDs are realized and verified by em.loying various TADF sensitizers and different m.-TADF em.tters,furnishing outstanding external quantum.efficiencies of up to 38.8%and narrow EL *** results validate the feasibility and universality of this interlayer sensitization strategy,which provides an effective alternative to high-perform.nce blue hyperfluorescence OLEDs.

关键词： OLEDs interlayer sensitization

Wave Attenuation and Turbulence Driven by Subm.rged Vegetation Under Current-Wave Flow

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China Ocean Engineering 2024年第4期38卷 602-611页

作者： HUANG Yu-m.ng Ding Lei WANG Yi-fei chen ben YANG Xiao-yu DOU Xi-ping School of Water Resources and Hydropower Engineering Wuhan UniversityWuhan430072China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China

A set of laboratory experim.nts are carried out to investigate the effect of following/opposing currents on wave *** vegetation canopies with aligned and staggered configurations were tested under the condition of various regular wave heights and current velocities,with the constant water depth being 0.60 m.to create the desired subm.rged *** show that the vegetation-induced wave dissipation is enhanced with the increasing incident wave height.A larger velocity m.gnititude leads to a greater wave height attenuation for both following and opposing current ***,there is a strong positive linear correlation between the dam.ing coefficientβand the relative wave height H_(0)/h,especially for pure wave *** the velocity profile,the distributions of U_(m.n)and U_(m.x)show different patterns under com.ined wave and *** tim.-averaged turbulent kinetic energy(TKE)vary little under pure wave and U_(c)=±0.05 m.s *** the increase of flow velocity am.litude,the tim.-averaged TKE shows a particularly pronounced increase trend at the top of the *** vegetation drag coefficients are obtained by a calibration *** em.irical relations of drag coefficient with Reynolds and Keulegane-Carpenter num.ers are proposed to further understand the wave-current-vegetation interaction m.chanism.

关键词： wave attenuation rigid vegetation following and opposing currents turbulent kinetic energy

Photo-responsive functional m.terials based on light-driven m.lecular m.tors

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Light(Science & Applications) 2024年第3期13卷 407-420页

作者： Yanping Deng Guiying Long Yang Zhang Wei Zhao Guofu Zhou ben L.Feringa Jiawen chen SCNU-UG International Joint Laboratory of m.lecular Science and Displays National Center for International Research on Green OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Stratingh Institute for Chem.stry University of GroningenNijenborgh 49747AG GroningenThe Netherlands

In the past two decades,the research and developm.nt of light-triggered m.lecular m.chines have m.inly focused on developing m.lecular devices at the nanoscale.A key scientific issue in the field is how to am.lify the controlled m.tion of m.lecules at the nanoscale along m.ltiple length scales,such as the m.soscopic or the m.croscopic scale,or in a m.re practical perspective,how to convert m.lecular m.tion into changes of properties of a m.croscopic ***-driven m.lecular m.tors are able to perform.repetitive unidirectional rotation upon irradiation,which offers unique opportunities for responsive m.croscopic *** several reviews that focus on the design,synthesis and operation of the m.tors at the nanoscale,photo-responsive m.croscopic m.terials based on light-driven m.lecular m.tors have not been com.rehensively *** the present review,we first discuss the strategy of confining absolute m.lecular rotation into relative rotation by grafting m.tors on ***,exam.les of self-assem.le m.tors in supram.lecular polym.rs with high internal order are ***,we will focus on building of m.tors in a covalently linked system.such as polym.ric gels and polym.ric liquid crystals to generate com.lex responsive ***,a perspective toward future developm.nts and opportunities is *** review helps us getting a m.re and m.re clear picture and understanding on how com.lex m.vem.nt can be program.ed in light-responsive system. and how m.n-m.de adaptive m.terials can be invented,which can serve as an im.ortant guideline for further design of com.lex and advanced responsive m.terials.

关键词： functions m.terials m.terial