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The Model Identification for Small Unmanned Aerial Rotorcraft Based on Adaptive Ant Colony Algorithm

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Journal of Bionic Engineering 2012年第4期9卷 508-514页

作者： Xusheng lei Kexin Guo School of Instrument Science and Opto-electronic Engineering Beihang University Beijing 100191 P. R. China Science and Technology on Inertial Laboratory Beijing 100191 P. R. China

This paper proposes a model identification method to get high performance dynamic model of a small unmanned aerial rotorcraft. With the analysis of flight characteristics, a linear dynamic model is constructed by the small perturbation theory. Using the micro guidance navigation and control module, the system can record the control signals of servos, the state infor- mation of attitude and velocity information in sequence. After the data preprocessing, an adaptive ant colony algorithm is proposed to get optimal parameters of the dynamic model. With the adaptive adjustment of the pheromone in the selection process, the proposed model identification method can escape from local minima traps and get the optimal solution quickly. Performance analysis and experiments are conducted to validate the effectiveness of the identified dynamic model. Compared with real flight data, the identified model generated by the proposed method has a better performance than the model generated by the adaptive genetic algorithm. Based on the identified dynamic model, the small unmanned aerial rotorcraft can generate suitable control parameters to realize stable hovering, turning, and straight flight.

关键词： small unmanned aerial rotorcraft model identification adaptive ant colony

Hydrodynamic Performance of A Dual-Floater Integrated System Com-bining Hybrid WECs and Floating Breakwaters

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China Ocean Engineering 2022年第6期36卷 969-979页

作者： FU lei CHENG Yong School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

The high investment and low return of wave energy converters(WECs)seriously hamper their large-scale commercial *** integration of WECs and floating breakwaters is conducive to enhance the competitiveness of wave energy *** objective of this paper is to investigate the hydrodynamic performance of a WEC-breakwater integrated system combining an upstream oscillating water column(OWC)and a downstream oscillating buoy(OB)via numerical simulations and physical experiments.A nonlinear numerical wave flume using Star-CCM+software is employed to obtain calculated results,where a tiny transverse gap is set between the flume wall and the block surface to simulate a similar two-dimensional(2D)*** corresponding physical experiments are also carried out in a practical wave flume to verified the numerical *** comparison of the isolated and hybrid system shows that the hybrid design leads to the decreased conversion efficiency of each WEC,but improves the transmission performance of the hybrid *** wave resonance between two devices causes the abrupt reduction of OWC efficiency and a positive correlation exists with the OB *** total efficiency of the hybrid system is raised by an optimal opening ratio,a shallow OWC draft and a short spacing *** for the OWC draft,other design parameters have weak effect on the wave attenuation of the hybrid *** paper can help understand hydrodynamics of the hybrid WECs integrated with breakwaters and improve their performances.

关键词： wave energy converters floating breakwater oscillating buoy oscillating water column numerical wave flume physical experiment

Cyclic Remote Implementation of Partially Unknown Quantum Operations

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Chinese Journal of Electronics 2021年第2期30卷 378-383页

作者： PENG Jiayin lei Hongxuan School of Mathematics and Information Science Neijiang Normal University School of Computer Science and Technology Taizhou University

We present a novel scheme of Cyclic remote implementation of partially unknown quantum operations(CRIPUQO) via a six-qubit entangled state as the quantum channel. Alice can remotely apply a partially unknown quantum operation Ud(d = 0, 1) to Bob’s qubit b, and Bob can remotely apply Udto Charlie’s site; meanwhile, Charlie can also remotely apply Udto Alice’s qubit c. It is pointed out that the CRIPUQO in the opposite direction can be perfectly achieved by changing the quantum channel. The scheme above is also generalized to systems having N observers, so that the CRIPUQO can be realized in quantum information networks with N observers in different directions by changing quantum channels.

关键词： quantum entanglement quantum channel CRIPUQO Alice's qubit quantum information networks quantum computing Bob's qubit Cyclic remote implementation Charlie's site partially unknown quantum operation six-qubit entangled state

Modeling the Wettability of Microstructured Hydrophobic Surface Using Multiple-relaxation-time Lattice Boltzmann Method

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Journal of Bionic Engineering 2022年第5期19卷 1460-1471页

作者： lei Tian Liuchao Qiu College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China

Wetting properties are significant for a hydrophobic surface and normally characterized by the equilibrium contact *** this manuscript,a mesoscopic method based on multiphase multiple-relaxation-time Lattice Boltzmann method has been presented and applied to simulate the contact angle at three-phase interfaces of a solid surface with micro-pillar *** influence of different parameters including pillar height,pillar width,inter-pillar spacing,intrinsic contact angle and the volume of the liquid drop on the equilibrium contact angle has been comprehensively *** effect of geometry parameters of the micro-pillar structure on the wetting transition from Cassie–Baxter state to Wenzel state has also been *** results indicate that when the inter-pillar spacing is less than a certain value or the pillar height is greater than a certain value,the contact form between the droplet and the surface satisfies the Cassie–Baxter *** the contact form satisfies the Cassie–Baxter state,the contact angle gradually increases with the increase of the inter-pillar spacing;the contact angle does not change significantly with the pillar height;the contact angle gradually decreases and approaches the intrinsic contact angle with the pillar width ***,the contact angle increases with the increase of the intrinsic contact angle,and the contact angle is not sensitive to the change of droplet volume when the droplet volume is between 0.5 and10μl.

关键词： Bioinspired hydrophobic surface Wettability Cassie-Baxter state Wenzel state Lattice Boltzmann method Mesoscale simulation

Deep learning augmented microscopy: a faster, wider view, higher resolution autofluorescenceharmonic microscopy

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Light(Science & Applications) 2022年第5期11卷 746-747页

作者： lei Tian Department of Electrical and Computer Engineering Boston UniversityBostonMA 02215USA Department of Biomedical Engineering Boston UniversityBostonMA 02215USA

Deep learning enables bypassing the tradeoffs between imaging speed,field of view,and spatial resolution in autofluorescence-harmonic microscopy.

关键词： harmonic Deep faster

Convergence of Self-Tuning Regulators Under Conditional Heteroscedastic Noises with Unknown High-Frequency Gain

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Journal of Systems Science & Complexity 2021年第1期34卷 236-250页

作者： ZHANG Yaqi GUO lei Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

In the classical theory of self-tuning regulators, it always requires that the conditional variances of the systems noises are bounded. However, such a requirement may not be satisfied when modeling many practical systems, and one significant example is the well-known ARCH(autoregressive conditional heteroscedasticity) model in econometrics. The aim of this paper is to consider self-tuning regulators of linear stochastic systems with both unknown parameters and conditional heteroscedastic noises, where the adaptive controller will be designed based on both the weighted least-squares algorithm and the certainty equivalence principle. The authors will show that under some natural conditions on the system structure and the noises with unbounded conditional variances, the closed-loop adaptive control system will be globally stable and the tracking error will be asymptotically ***, this paper provides a significant extension of the classical theory on self-tuning regulators with expanded applicability.

关键词： ARCH model conditional heteroscedasticity convergence self-tuning regulator weighted least-squares algorithm

Engineering yolk-shell CuCo_(2)S_(4)@Cu_(2)O Z-scheme nanoreactors for accelerating generation of value-added chemicals and of degradation multi-organic contaminants

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Journal of Materials Science & Technology 2023年第25期156卷 54-63页

作者： Xue Feng lei Zhang College of Chemistry Liaoning University66 Chongshan Middle RoadShenyang 110036China

The synthesis of solar-driven chemical value-added products and the degradation of pollutants is a promising approach for sustainable development. However, achieving these works via photocatalysts with efficient charge-separation, photo-absorption is challenging. A yolk-shell CuCo_(2)S_(4)@Cu_(2)O Z-scheme nanoreactor (YS-CuCo_(2)S_(4)@Cu_(2) O-NR) with octahedron Cu_(2)O as the core and tubular CuCo2 S4 as the shell, has been synthesized by regulating composition and morphology. YS-CuCo_(2)S_(4)@Cu_(2)O-NR shows superior photocatalytic activities for producing H_(2) O_(2) collaborates by selective oxidation of benzyl alcohol (BA) to high value-added benzaldehyde (BAD)/utilized Fenton-like reaction to degrade multi-pollutants through space-confinement effect, reaching 80% conversion and 99% selectivity of BA, a yield of 12 mM g^(−1) for H_(2)O_(2) and above 90% degradation efficiency for multi-pollutants. A photocatalysis nanoconfinement reactor system is proposed and demonstrated by using yolk-shell to enhance the performance of the chemical reaction. Mechanism studies show that the yolk-shell provides confined space to accelerate redox reaction kinetics;while the inner void promotes light harvesting and keeps yolk Cu_(2) O from deactivation;combined with the Z-scheme charge transfer, engineering Cu^(+) /Cu^(2+) active composition, they are favorable for enhancing the H_(2) O_(2) generation and Fenton-like activity. These findings provide new opportunities for application of yolk-shell Z-scheme metal-oxide-based photocatalysts.

关键词： Octahedron yolk-shell structure catalyzer Z-scheme charge transfer H2O_(2)generation Selective oxidation of BA Fenton-like reaction

Two-Stage Online Debiased Lasso Estimation and Inference for High-Dimensional Quantile Regression with Streaming Data

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Journal of Systems Science & Complexity 2024年第3期37卷 1251-1270页

作者： PENG Yanjin WANG lei School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

In this paper,the authors propose a two-stage online debiased lasso estimation and statistical inference method for high-dimensional quantile regression(QR)models in the presence of streaming *** the first stage,the authors modify the QR score function based on kernel smoothing and obtain the online lasso smoothed QR estimator through iterative *** estimation process only involves the current data batch and specific historical summary statistics,which perfectly accommodates to the special structure of streaming *** the second stage,an online debiasing procedure is carried out to eliminate biases caused by the lasso penalty as well as the accumulative approximation error so that the asymptotic normality of the resulting estimator can be *** authors conduct extensive numerical experiments to evaluate the performance of the proposed *** experiments demonstrate the effectiveness of the proposed method and support the theoretical *** application to the Beijing PM2.5 Dataset is also presented.

关键词： Adaptive tuning asymptotic normality debiased lasso online updating quantile regres-sion

Role of interfacial water in adhesion,friction,and wear--A critical review

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Friction 2021年第1期9卷 1-28页

作者： lei CHEN Linmao QIAN Tribology Research Institute State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu 610031China

Surficial water adsorption and interfacial water condensation as natural phenomena that can alter the contact status of the solid interface and tribological performances are crucial in all length scales,i.e.,from earthquakes to skating at the macroscale level and even to micro/nano-electromechanical systems(M/NEMS)at the microscale/nanoscale *** water exhibits diverse structure and properties from bulk water because of its further interaction with solid *** this paper,the evolutions of the molecular configuration of the adsorbed water layer depending on solid surface chemistry(wettability)and structure,environmental conditions(i.e.,relative humidity and temperature),and experimental parameters(i.e.,sliding speed and normal load)and their impacts on tribological performances,such as adhesion,friction,and wear,are systematically *** on these factors,interfacial water can increase or reduce adhesion and friction as well as facilitate or suppress the tribochemical wear depending on the water condensation kinetics at the interface as well as the thickness and structure of the involved interfacial water.

关键词： water adsorption water condensation adhesion friction tribochemical wear