This paper studies a geometric attitude tracking control problem of quadrotor unmanned aerial vehicles (UAVs) with adaptive extended state observers (AESOs). Through coordinate transformation, the error dynamic of AES...
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Ceramic matrix composites(CMCs)structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerosp...
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Ceramic matrix composites(CMCs)structural components encounter the dual challenges of severe mechanical conditions and complex electromagnetic environments due to the increasing demand for stealth technology in aerospace *** address various functional requirements,this study integrates a biomimetic strategy inspired by gradient bamboo vascular bundles with a novel dual-material 3D print-ing *** distinct bamboo-inspired structural configurations Cf/SiC composites are designed and manufactured,and the effects of these different structural configurations on the CVI process are *** method is utilized to characterize the relationship between interface bonding strength and mechanical *** results reveal that the maximum flexural strength and fracture toughness reach 108.6±5.2 MPa and 16.45±1.52 MPa m1/2,respectively,attributed to the enhanced crack propagation resistance and path caused by the weak fiber-matrix ***,the bio-inspired configuration enhances the dielectric loss and conductivity loss,exhibiting a minimum reflection loss of-24.3 dB with the effective absorption band of 3.89 *** work introduces an innovative biomimetic strategy and 3D printing method for continuous fiber-reinforced ceramic composites,expanding the ap-plication of 3D printing technology in the field of CMCs.
Within the thriving e-commerce landscape,some unscrupulous merchants hire spammer groups to post misleading reviews or ratings,aiming to manipulate public perception and disrupt fair market *** phenomenon has prompted...
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Within the thriving e-commerce landscape,some unscrupulous merchants hire spammer groups to post misleading reviews or ratings,aiming to manipulate public perception and disrupt fair market *** phenomenon has prompted a heightened research focus on spammer groups *** the e-commerce domain,current spammer group detection algorithms can be classified into three categories,i.e.,Frequent Item Mining-based,graph-based,and burst-based ***,existing graph-based algorithms have limitations in that they did not adequately consider the redundant relationships within co-review graphs and neglected to detect overlapping members within spammer *** address these issues,we introduce an overlapping spammer group detection algorithm based on deep reinforcement learning named ***,the algorithm filters out highly suspicious products and gets the set of reviewers who have reviewed these ***,taking these reviewers as nodes and their co-reviewing relationships as edges,we construct a homogeneous co-reviewing ***,to efficiently identify and handle the redundant relationships that are accidentally formed between ordinary users and spammer group members,we propose the Auto-Sim algorithm,which is a specifically tailored algorithm for dynamic optimization of the co-reviewing graph,allowing for adjustments to the reviewers’relationship network within the ***,candidate spammer groups are discovered by using the Ego-Splitting overlapping clustering algorithm,allowing overlapping members to exist in these ***,these groups are refined and ranked to derive the final list of spammer *** results based on real-life datasets show that our proposed DRL-OSG algorithm performs better than the baseline algorithms in Precision.
Outlier detection is one of the hot topics in the field of machine learning and data mining. At present, there are many kinds of outlier detection algorithms. The accuracies of traditional outlier detection algorithms...
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Hybrid systems consisting of superconducting circuits and magnon systems are a promising platform for quantum ***,realizing high-fidelity magnon state preparation and manipulation remains an outstanding challenge due ...
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Hybrid systems consisting of superconducting circuits and magnon systems are a promising platform for quantum ***,realizing high-fidelity magnon state preparation and manipulation remains an outstanding challenge due to the complexity of interactions and noise sources in hybrid ***,we propose a coherence-preserving magnon state manipulation *** engineering a superconducting-magnon coupling pulse and combining it with dynamical decoupling pulses,we design a composite pulse *** demonstrate the manipulation and preparation of non-classical states of magnons with a fidelity of up to 98%under realistic *** designs significantly improve the fidelity of manipulation and robustness to noise in hybrid systems compared to existing *** results pave the way for practical applications of quantum magnonics platforms.
作者:
Hou, RuijieYu, YangLi, XiuxianTongji University
Department of Control Science and Engineering College of Electronics and Information Engineering Shanghai201800 China Tongji University
Shanghai Research Institute for Intelligent Autonomous Systems National Key Laboratory of Autonomous Intelligent Unmanned Systems Frontiers Science Center for Intelligent Autonomous Systems Ministry of Education Shanghai Institute of Intelligent Science and Technology Shanghai201210 China
This article focuses on online composite optimization over multiagent networks. In the distributed setting, each agent has its own local loss function, which consists of a convex, strongly convex or strongly convex an...
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Moiré fringe analysis holds significant importance in the assessment of flow fields, while deep learning is advancing rapidly and is frequently employed to handle complex computational challenges. In this paper, ...
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This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-bas...
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This study focuses on the electrical properties and microstructure of polypropylene(PP)-based blends used for cable insulation in nuclear power plants(NPPs).The PP-based blend,comprising isotactic PP and propylene-based elastomer(PBE)at concentrations ranging from 0 to 50 wt%,underwent a melt blending process and subsequent cobalt-60 gamma-ray irradiation with doses ranging from 0 to 250 *** conductivity,trap distribution,and alternating(AC)breakdown strength were chosen to assess the insulation *** results indicate that the addition of PBE significantly improves the electrical properties of PP under *** PP,the electrical conductivity increased with irradiation,whereas the trap depth and breakdown strength decreased ***,for the blend,these changes initially exhibit opposite *** the irradiation was increased to 250 kGy,the AC breakdown strength of the blend improved by more than 21%compared to that of *** physical and chemical structures of the samples were investigated to explore the improvement *** results offer insights into the design of new cable-insulation materials suitable for NPPs.
We present a decoupled,linearly implicit numerical scheme with energy stability and mass conservation for solving the coupled Cahn-Hilliard *** time-discretization is done by leap-frog method with the scalar auxiliary...
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We present a decoupled,linearly implicit numerical scheme with energy stability and mass conservation for solving the coupled Cahn-Hilliard *** time-discretization is done by leap-frog method with the scalar auxiliary variable(SAV)*** only needs to solve three linear equations at each time step,where each unknown variable can be solved *** is shown that the semi-discrete scheme has second-order accuracy in the temporal *** convergence results are proved by a rigorous analysis of the boundedness of the numerical solution and the error estimates at different *** examples are presented to further confirm the validity of the methods.
An optical emission spectroscopy(OES)method with a non-invasive measurement capability,without inducing disturbance to the discharge,represents an effective method for material ***,when the OES method is employed to m...
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An optical emission spectroscopy(OES)method with a non-invasive measurement capability,without inducing disturbance to the discharge,represents an effective method for material ***,when the OES method is employed to monitor the trace erosion product within the ceramic channel of a Hall thruster,it becomes challenging to distinguish between signal and *** this study,we propose a model filtering method based on the signal characteristics of the Hall thruster plume *** method integrates the slit imaging and spectral resolution features of the *** this method,we extract the spectral signals of the erosion product and working gas from the Hall thruster under different operating *** results indicate that our new method performs comparably to the traditional method without model filtering when extracting atom signals from strong xenon working ***,for trace amounts of the erosion product,our approach significantly enhances the signal-to-noise ratio(SNR),enabling the identification of extremely weak spectral signals even under low mass flow rate and low-voltage *** obtain boron atom concentration of 3.91×10^(-3) kg/m^(3) at a mass flow rate of 4×10^(-7) kg/s and voltage of 200 V while monitoring a wider range of thruster operating *** new method proposed in this study is suitable for monitoring other low-concentration elements,making it valuable for materials processing,environmental monitoring and space propulsion applications.
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