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Distributed swarm control for multi-robot systems inspired by shepherding behaviors

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Science China(Technological Sciences) 2024年第7期67卷 2191-2202页

作者： SUN GuiBin GU HaiBo lÜJinHu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Zhongguancun laboratory Beijing 100094China

Swarming behaviors play an eminent role in both biological and engineering research, and show great potential applications in many emerging fields. Traditional swarming models still lack integrity, uniformity, and stability in swarm forming processes,resulting in fragmentation and void phenomena. Inspired by the shepherding behaviors observed in nature, we propose an integrated negotiation-control scheme for distributed swarm control of massive robots. The core idea of this scheme is that the robots at the boundary of the group herd the internal robots to form an equilibrium swarm. For this purpose, we introduce a concept of virtual group center towards which boundary robots herd internal robots. Then, a distributed negotiation mechanism is designed to allow each robot to negotiate the virtual group center only through local interactions with its neighbors. After that, we propose a shepherding-inspired swarm control law to drive a group of robots to form an integrated, uniform, and stable configuration from any initial states. Both numerical and flight simulations are presented to verify the effectiveness of our proposed swarm control scheme.

关键词： swarm control multi-robot system negotiation-control scheme shepherding behavior

Promoting Older Adults' Engagement in Disaster Recovery Through Supportive Relationships, Partnerships, and Collaboration: Perspectives of Social Work Practitioners and Human Service Professionals

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International Journal of Disaster Risk Science 2024年第2期15卷 265-276页

作者： Julie l.Drolet Mahed Choudhury Faculty of Social Work University of CalgaryEdmontonAB T5J 4P6Canada

Shifting demographics—that is, the growing number of older adults in Canada and internationally—and intersecting climatic risks create a complex landscape of aging in place in disaster contexts. Some older adults are vulnerable due to their underlying health conditions and limited physical mobility. Yet they also exhibit resilience in a distinct manner, owing to their wealth of knowledge, wisdom, and ability to navigate adversities. This article elucidates potential avenues for promoting the involvement of older adults in disaster recovery efforts. Our intention is to recognize and foster older adult resilience and mitigate vulnerability by drawing upon insights from the study titled “In the Aftermath of the 2016 Alberta Wildfires: The Role of Social Work Practitioners and Human Service Professionals in long-Term Disaster Recovery.” Employing a qualitative research approach, that study recruited 51 participants for semistructured interviews and focus groups. A thematic analysis of the collected data unveiled the pivotal roles played by social workers and human service practitioners in facilitating recovery from the 2016 wildfires in the research. Notably, three overarching themes emerged concerning the promotion of older adults' involvement in disaster recovery: fostering supportive relationships, building partnerships and enhancing collaboration, and addressing ongoing challenges. These findings offer valuable insights into how social work practitioners and human service professionals can effectively facilitate the engagement of older adults in disaster recovery initiatives. This article emphasizes the significance of actively promoting the participation of older adults in disaster mitigation efforts, thereby fostering greater resilience within communities.

关键词： Alberta wildfires Canada Disaster recovery Older adults Partnerships and collaboration Social work

Recent Advances in Catalytic Carbonylation Reactions in Alternative Reaction Media

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Chinese Journal of Chemistry 2024年第4期42卷 406-429页

作者： Csaba Árvai lászló T.Mika Department of Chemical and Environmental Process Engineering Faculty of Chemical Technology and BiotechnologyBudapest University of Technology and EconomicsMűegyetem rkp.3H-1111 BudapestHungary

Since the discovery of the hydroformylation(oxo-synthesis or Roelen reaction)and the Reppe-reaction,the transition metal-catalyzed carbonylation reactions,providing versatile,facile,and even atom-economic methods for the selective incorporation of C=O functionality to various skeletons,have gained tremendous importance in synthetic organic chemistry from laboratories to industrial *** carbonylation of carbon-carbon multiple bonds,aromatic halides,triflates,etc.,in the presence of various nucleophiles has led the way to produce aldehydes,carboxylic acids,esters,amides,etc.,in the fine chemical ***,these protocols usually proceed in conventional,fossil-based,and usually toxic reaction ***,several attempts have been directed to developing efficient carbonylation methods in alternative,less harmful,non-fossil-based and even in renewable reaction *** this review,we overview the recent applications of alternative solvents such as water,biomass-based alcohols,γ-valerolactone(GVl),2-methyltetrahydrofuran(2-MeTHF),ionic liquids(Ils),deep eutectic solvents(DES),alkyl levulinates,limonene,α-pinene,and dimethyl carbonate as well as fluorous media to improve efficiency,safety and environmentally benign nature of carbonylation protocols.

关键词： Carbonylation Catalysis Solvents Green chemistry Carbon monoxide Transition metals Homogeneous catalysis Palladium

Stability and performance analysis of the compressed Kalman filter algorithm for sparse stochastic systems

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Science China(Technological Sciences) 2024年第2期67卷 380-394页

作者： lI RongJiang GAN Die XIE SiYu lüJinHu Key laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Zhongguancun laboratory Beijing 100049China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

This paper considers the problem of estimating unknown sparse time-varying signals for stochastic dynamic *** deal with the challenges of extensive sparsity,we resort to the compressed sensing method and propose a compressed Kalman filter(KF)*** algorithm first compresses the original high-dimensional sparse regression vector via the sensing matrix and then obtains a KF estimate in the compressed low-dimensional ***,the original high-dimensional sparse signals can be well recovered by a reconstruction *** ensure stability and establish upper bounds on the estimation errors,we introduce a compressed excitation condition without imposing independence or stationarity on the system signal,and therefore suitable for feedback *** further present the performance of the compressed KF ***,we show that the mean square compressed tracking error matrix can be approximately calculated by a linear deterministic difference matrix equation,which can be readily evaluated,analyzed,and ***,a numerical example demonstrates that our algorithm outperforms the standard uncompressed KF algorithm and other compressed algorithms for estimating high-dimensional sparse signals.

关键词： sparse signal compressed sensing Kalman filter algorithm compressed excitation condition stochastic stability tracking performance

Neural-network-based fully distributed formation control for nonlinear multi-agent systems with event-triggered communication

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Science China(Technological Sciences) 2024年第1期67卷 209-220页

作者： ZHU Guoliang lIU KeXin GU HaiBo lÜJinHu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Zhongguancun laboratory Beijing 100094China

This paper investigates the consensus-based formation control problem for multi-agent systems with unknown nonlinear *** achieve the desired formation,we propose two formation controllers to achieve the desired formation,one based on system states and the other on system *** proposed controllers utilize adaptive gains to avoid global information and neural networks to estimate and compensate for *** proposed event-triggered schemes avoid continuous communication among agents and exclude the Zeno *** analysis reveals that formation errors are bounded,and numerical simulations are used to validate the effectiveness of the proposed approaches.

关键词： formation control neural network adaptive control event-triggered communication multi-agent systems

Four late-type Galaxies with Double Radio lobes and Properties of Such Galaxies

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Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： Z.S.Yuan X.Y.Gao Z.l.Wen J.l.Han National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio lobes from late-type galaxies is not fully *** samples are desired for a thorough investigation and *** utilizing the optical data from the newly released Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO VlA Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four late-type Galaxies with double Radio lobes(la GRls):J0217-3645,J0947+6220,J1412+3723 and J1736+*** previously known la GRls,we confirm the correlation between radio power P_(1.4GHz)and stellar mass M_(*)of host ***(25/35)la GRls belong to the blue cloud galaxies,while the newly identified cases in this work are located within the region of the red *** find a clear correlation between the differential radio power,i.e.,the offset from the P_(1.4GHz)-M_(*)relation,and the galaxy color,indicating that bluer galaxies at a fixed M_(*)tend to host more powerful radio ***,the majority(31/36)of la GRls are either located in a galaxy group or displaying a disturbed *** suggest that all of the galaxy mass,color and surrounding environment could play important roles in triggering radio lobes in late-type galaxies.

关键词： galaxies:active galaxies:jets galaxies:spiral radio continuum:galaxies

Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： l.Iniya B.Sivakumar G.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a Bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

Research of surface-enhanced Raman scattering on Ag@PMBA@C@Au hybrid nanoparticles

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Optoelectronics letters 2024年第2期20卷 65-69页

作者： TAN Enzhong lÜ Suye liberal Study College Beijing Institute of Petrochemical TechnologyBeijing 102617China

Monodispersed, biocompatible, and readily-functionalized hybrid reporter-embedded core-shell nanopartilces(NPs) have been prepared in a simple route. This composite offers a potential platform for immunochemical detection using surface-enhanced Raman scattering(SERS) due to their high sensitivity, good stability and biocompatiblity. This also provides a new platform for insight into SERS enhancement mechanism.

关键词： mechanism. readily SERS

Dual Additives for Stabilizing li Deposition and SEI Formation in Anode-Free li-Metal Batteries

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Energy & Environmental Materials 2024年第03期7卷 88-96页

作者： Baolin Wu Chunguang Chen Dmitri l.Danilov Zhiqiang Chen Ming Jiang Rüdiger-A.Eichel Peter H.l.Notten Forschungszentrum Jülich (IEK-9) RWTH Aachen University lNM Institute of MechanicsChinese Academy of Sciences School of Engineering Sciences University of Chinese Academy of Sciences Eindhoven University of Technology School of Electronics and Information Institute of Carbon Neutrality and New EnergyHangzhou Dianzi University University of Technology Sydney

Anode-free li-metal batteries are of significant interest to energy storage industries due to their intrinsically high ***,the accumulative li dendrites and dead li continuously consume active li during *** results in a short lifetime and low Coulombic efficiency of anode-free li-metal *** effective electrolyte additives can improve the li deposition homogeneity and solid electrolyte interphase (SEI) stability for anode-free li-metal ***,we reveal that introducing dual additives,composed of liAsF6 and fluoroethylene carbonate,into a low-cost commercial carbonate electrolyte will boost the cycle life and average Coulombic efficiency of NMC‖Cu anode-free li-metal *** NMC‖Cu anode-free li-metal batteries with the dual additives exhibit a capacity retention of about 75%after50 cycles,much higher than those with bare electrolytes (35%).The average Coulombic efficiency of the NMC‖Cu anode-free li-metal batteries with additives can maintain 98.3%over 100 *** contrast,the average Coulombic efficiency without additives rapidly decline to 97%after only *** situ Raman measurements reveal that the prepared dual additives facilitate denser and smoother li morphology during li *** dual additives significantly suppress the li dendrite growth,enabling stable SEI formation on anode and cathode *** results provide a broad view of developing low-cost and high-effective functional electrolytes for high-energy and long-life anode-free li-metal batteries.

关键词： anode-free lithium metal battery dual additives in situ Raman li growth SEI formation