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Frontiers of Structural and Civil Engineering 2024年第8期18卷 1195-1208页

作者： Dev Kunwar Singh CHAUHAN Pandu R.VUNDAVILLI Indian institute of Technology Bhubaneswar Bhubaneswar 752050India

The present work aims to develop an object tracking controller for the Stewart platform using a computer vision-assisted machine learning-based *** research is divided into two *** first module focuses on the design of a motion controller for the Physik Instrumente(PI)-based Stewart *** contrast,the second module deals with the development of a machine-learning-based spatial object tracking algorithm by collecting information from the Zed 2 stereo vision ***,simple feed-forward neural networks(NN)are used to predict the orientation of the top table of the *** training,the x,y,and z coordinates of the three-dimensional(3D)object,extracted from images,are used as the input to the *** contrast,the orientation information of the platform(that is,rotation about the x,y,and z-axes)is considered as the output from the *** orientation information obtained from the network is fed to the inverse kinematics-based motion controller(module 1)to move the platform while tracking the *** training,the optimised NN is used to track the continuously moving 3D *** experimental results show that the developed NN-based controller has successfully tracked the moving spatial object with reasonably good accuracy.

关键词： Stewart platform feed-forward neural networks motion controller inverse kinematics stereo vision

Ablative behavior and mechanism of SiC_(f) /SiBCZr composites prepared by PIP process

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Journal of Advanced Ceramics 2024年第1期13卷 124-134页

作者： Mingwei Chen Yuliang Zhao Haipeng Qiu Shijian Liu Weijie Xie Yi Chen Qiyue Zhang AVIC Manufacturing Technology institute Beijing 100130China

SiC_(f)/SiBCZr composites were prepared by polymer precursor impregnation and pyrolysis process with near stoichiometric ratio SiC fiber preform as reinforcement phase and SiBCZr multiphase ceramic precursor as impregnating *** results highlighted that the SiC_(f)/SiBCZr composites exhibited excellent ablative properties after ablative tests at 1200℃/3600 s and 1400℃/3600 s,and the strength retention rates of the composites reached 90%and 85%,*** was mainly due to the liquid sealing effect of the ablative products represented by B2O_(3) and SiO_(2)∙B_(2)O_(3),which inhibited the ablative reaction by reducing the diffusion rate of the oxidation medium,and the solid pinning effect of the substances represented by SiO_(2),ZrO_(2),and ZrSiO_(4),which could play high viscosity and high strength characteristics to improve anti-erosion *** above-mentioned SiC_(f)/SiBCZr composites with corrosion resistance,oxidation resistance,and ablative resistance provided a solid material foundation and technical support for the development of reusable spacecraft hot-end components.

关键词： near stoichiometric ratio SiC fiber SiC_(f)/SiBCZr composite liquid sealing effect solid pinning effect

Controlling Tendons to Modulate Stiffness of a Planar-to-Spatial Tendon-Driven Continuum Manipulator Under External Uncertain Forces

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Journal of Bionic Engineering 2024年第2期21卷 821-841页

作者： Vipin Pachouri Pushparaj Mani Pathak Indian institute of Technology Roorkee Roorkee247667India

Continuum manipulators(CM)are soft and flexible manipulators with large numbers of degrees of freedom and can perform complex tasks in an unstructured ***,their deformability and compliance can deviate distal tip under uncertain external *** address this challenge,a novel tension-based control scheme has been proposed to modulate the stiffness of a tendon-driven CM,reducing the tip position errors caused by uncertain external *** minimize the tip position error,a virtual spring is positioned between the deviated and the desired tip *** proposed algorithm corrects the manipulator deviated tip position,improving tension distribution and stiffness profile,resulting in higher stiffness and better *** corresponding task space stiffness and condition numbers are also computed under different cases,indicating the effectiveness of the tension control scheme in modulating the manipulator's *** validation conducted on an in-house developed prototype confirms the practical feasibility of the proposed approach.

关键词： Continuum arm Hyper-redundant robots Variable stiffness manipulator Tension-based control Mechatronic systems

Priority effects of forbs arriving early:the role of root interaction and asymmetric competition

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Ecological Processes 2024年第1期13卷 53-65页

作者： Xiaohong Yan Xiliang Li Ke Jin institute of Grassland Research Chinese Academy of Agricultural Sciences

Background The priority effect of plant arrival is a key driver of community assembly and ecosystem succession during the restoration of degraded plant communities. However, the significance of the arrival order of different plant functional groups and their interactions with community assemblies remains unclear. Using a phytotron experiment with three fully crossed factors, we investigated the underlying mechanisms of priority effects and their relationships with the biomass and biodiversity effects in mixed plant communities by manipulating the order of arrival of species, isolation of roots, and removal of specific *** The results showed that the strength and direction of priority effects were influenced by arrival order, root interactions, asymmetric competition among species, and their interactions. The identities of early and late-sown species also determined the magnitude of priority effects. The priority effects were stronger in grass-first(24.76%) and legume-first communities(24.48%) than in forb-first communities. The pot biomass of the different priority treatments was highest in grass-first(5.85 g), followed by legume-first(3.94 g) and forb-first(2.48 g). The order of arrival in the mixture significantly affected the net biodiversity effects(P < 0.001), which were driven by dominance effects. The community had lower overall biomass when forbs were sown first, whereas the species grown later had fewer costs with an increased overall net benefit for the resulting *** Our results emphasize that root interactions and asymmetric competition are vital determinants of order-specific priority effects in community assemblies. In addition, the importance of the priority effect of forbs sown first is related to community assembly, which may be a key determinant in successfully establishing a highly diverse community in the early stages of restoration. Species with weak competition should be considered in the early stage of community ass

关键词： Community assembly Order of arrival Overyielding Plant functional group Root isolation

Resource management at the network edge for federated learning

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Digital Communications and Networks 2024年第3期10卷 765-782页

作者： Silvana Trindade Luiz F.Bittencourt Nelson L.S.da Fonseca institute of Computing State University of CampinasCampinasBrazil

Federated learning has been explored as a promising solution for training machine learning models at the network edge,without sharing private user *** limited resources at the edge,new solutions must be developed to leverage the software and hardware resources as the existing solutions did not focus on resource management for network edge,specially for federated *** this paper,we describe the recent work on resource manage-ment at the edge and explore the challenges and future directions to allow the execution of federated learning at the *** such as the discovery of resources,deployment,load balancing,migration,and energy effi-ciency are discussed in the paper.

关键词： Resource management Edge computing Federated learning Machine learning

On equivalence of state-based potential games

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Science China(Information Sciences) 2024年第6期67卷 313-327页

作者： Han WU Jinhuan WANG institute of Mathematics School of ScienceHebei University of Technology

In this paper, we explore state-based potential games using the semi-tensor product of ***, applying the potential equation, we derive both a necessary and sufficient condition as well as a sufficient condition to verify whether a state-based game qualifies as a potential game. Next, we present two static equivalence conditions of state-based potential games. We then delve into dynamic equivalence. We propose a criterion that allows us to identify state-based games that are dynamically equivalent to state-based potential games and share similar dynamic properties. Ultimately, we introduce the concept of state-based networked evolutionary games. We provide a necessary and sufficient condition to ensure that a state-based networked evolutionary game can be classified as a state-based potential game.

关键词： semi-tensor product of matrices state-based potential game verification equivalence state-based networked evolutionary game

A review on edge analytics:Issues,challenges,opportunities,promises,future directions,and applications

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Digital Communications and Networks 2024年第3期10卷 783-804页

作者： Sabuzima Nayak Ripon Patgiri Lilapati Waikhom Arif Ahmed National institute of Technology Silchar India Ericsson Sweden

Edge technology aims to bring cloud resources(specifically,the computation,storage,and network)to the closed proximity of the edge devices,i.e.,smart devices where the data are produced and *** computing and application in edge devices lead to emerging of two new concepts in edge technology:edge computing and edge *** analytics uses some techniques or algorithms to analyse the data generated by the edge *** the emerging of edge analytics,the edge devices have become a complete ***,edge analytics is unable to provide full support to the analytic *** edge devices cannot execute advanced and sophisticated analytic algorithms following various constraints such as limited power supply,small memory size,limited resources,*** article aims to provide a detailed discussion on edge *** key contributions of the paper are as follows-a clear explanation to distinguish between the three concepts of edge technology:edge devices,edge computing,and edge analytics,along with their *** addition,the article discusses the implementation of edge analytics to solve many problems and applications in various areas such as retail,agriculture,industry,and ***,the research papers of the state-of-the-art edge analytics are rigorously reviewed in this article to explore the existing issues,emerging challenges,research opportunities and their directions,and applications.

关键词： Edge analytics Edge computing Edge devices Big data Sensor Artificial intelligence Machine learning Smart technology Healthcare

Topological non-reciprocal robust waveguide transport

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 39-45页

作者： Ruizhi Dong Yihuan Zhu Dongxing Mao Xu Wang Yong Li institute of Acoustics Tongji UniversityShanghai 200092China

Devices that surpass the restriction of reciprocity of classical physical waves have brought intriguing possibilities for wave ***-reciprocal acoustic devices that rely on the viscosity of the medium or nonlinear effect have low efficiency and distortion problems respectively,and poor immunity to *** appearance of acoustic topological insulators achieves nonreciprocal transport with high ***,the local nature of topological states means that their appearance depends on a system with a larger *** is,most of the area of a topological device is occupied by useless lattices that do not directly contribute to non-reciprocal *** extra cost of topology protection severely limits the application scenarios of topology states,decreases the cost-effectiveness of topology devices,and is not conducive to device miniaturization and *** this work,we construct an acoustic three-layer heterojunction by introducing two types of domain walls into a conventional quantum Hall effect acoustic topological insulator,and successfully construct a non-reciprocal scattering network that forms topological modes spanning the interlayer *** extended states are still protected by bulk-band topology,making their non-reciprocity robust against *** structure flawlessly realizes the path broadening in a two-dimensional topological system and can accomplish functions such as non-reciprocal acoustic splitting and multichannel *** work opens up opportunities for developing topological-insulator-based non-reciprocal devices in acoustics.

关键词： reciprocal topological topology

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Achieving simultaneously high conversion and high selectivity for light olefins directly producing from syngas

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Science China Chemistry 2024年第3期67卷 753-754页

作者： Yuhan Sun Shanxi Research institute Huairou Research LaboratoryTaiyuan 030032China institute of Carbon Neutrality ShanghaiTech UniversityShanghai 201210China

The activity and selectivity are two primary indexes of a successful catalyst for chemical reactions. However,achieving a high activity and a high selectivity simultaneously is a long-standing challenge in catalysis, the socalled activity-selectivity trade-off. In the article recently published in Science, a research team led by Prof.

关键词： selectivity simultaneous catalysis

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Predicting transformer temperature field based on physics-informed neural networks

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High Voltage 2024年第4期9卷 839-852页

作者： Pengfei Tang Zhonghao Zhang Jie Tong Tianhang Long Can Huang Zihao Qi China Electric Power Research institute BeijingChina

The safe operation of oil-immersed transformers is critical to the safety and stability of the power *** the operating time increases,the failure rate of oil-immersed transformers shows an increasing trend,posing serious challenges to safe *** is necessary to investigate the internal state of the oil-immersed transformer to improve the digital degree and achieve digitalisation and intelligent operation and maintenance.A physics-informed neural network(PINN)for oil-immersed transformers was introduced to reconstruct the temperature distribution inside the *** to the approach,the loss function of the network would be optimised by incorporating physical constraint loss terms including heat transfer equations,initial conditions and boundary *** results show that the method proposed can be used to reconstruct and predict the temperature field of transformers in a few seconds with satisfactory *** conclusion,the PINN proposed outperforms deep neural networks in terms of accuracy,reliability and interpretability,especially in data-poor cases.

关键词： immersed conclusion constraint