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Polyhedral Feasible Set Computation of MPC-Based Optimal Control Problems

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IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 765-770页

作者： Lantao xie Lei xie Hongye Su Jingdai Wang State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang UniversityHangzhou 310027China College of Chemical and Biological Engineering Zhejiang UniversityHangzhou 310027China IEEE

Feasible sets play an important role in model predictive control(MPC) optimal control problems(OCPs). This paper proposes a multi-parametric programming-based algorithm to compute the feasible set for OCP derived from MPC-based algorithms involving both spectrahedron(represented by linear matrix inequalities) and polyhedral(represented by a set of inequalities) constraints. According to the geometrical meaning of the inner product of vectors, the maximum length of the projection vector from the feasible set to a unit spherical coordinates vector is computed and the optimal solution has been proved to be one of the vertices of the feasible set. After computing the vertices,the convex hull of these vertices is determined which equals the feasible set. The simulation results show that the proposed method is especially efficient for low dimensional feasible set computation and avoids the non-unicity problem of optimizers as well as the memory consumption problem that encountered by projection algorithms.

关键词： Feasible set computation linear matrix inequalities(LMIs) model predictive control(MPC) polyhedron

Existence Results of Damped Second Order Impulsive Functional Differential Equations with Infinite Delay

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Acta Mathematicae Applicatae Sinica 2019年第3期35卷 564-579页

作者： Sheng-li xie Yi-ming xie School of Mathematics&Physics Urban Construction CollegeAnhui Jianzhu University School of Civil Engineering Anhui Jianzhu UniversityHefei 230601China

Using the Monch fixed point theorem and progressive estimation method,we study the existence,uniqueness and regularity of mild solutions for damped second order impulsive functional differential equations with infinite delay in Banach *** compactness assumption on associated family of operators and the impulsive term,some restrictive conditions on a priori estimation,noncompactness measure estimation and the impulsive term have not been used,our results are different from some known ***,a noncompact semigroup example explains the obtained results.

关键词： damped second order impulsive functional differential equations mild solution strong solution classical solution measure of noncompactness

THREE-DIMENSIONAL NUMERICAL MODELLING OF THE WAVE-IN-DUCED RIP CURRENTS UNDER IRREGULAR BATHYMETRY

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Journal of Hydrodynamics 2012年第6期24卷 864-872页

作者： xie Ming-xiao School of Civil Engineering Tianjin University Tianjin Research Institute for Water Transport Engineering Ministry of Transport

A process-based 3-D hydrodynamic model is established to simulate the rip current structures under irregular bathymetry. The depth-varying wave-induced residual momentum, the surface rollers, the turbulent mixing and the wave-current interactions are considered. Experimental datasets are used to validate the model, and it is shown that the model can effectively describe the 3-D structures of the rip currents in both normal and oblique wave incident cases. The flow patterns of the rip currents see various characteristics for different incident wave directions. In the normal incident case, pairs of counter-rotating primary circulation cells are formed, and an offshore rip flow occurs in the embayment troughs. The peak seaward velocities occur at the top of the bed boundary layer, and the undertow is incorporated in addition to the rip currents. In the oblique incident case, the longshore currents are dominant, which result in a meandering flow along the depth contour, and the undertow is weaker compared to that in the normal incident condition.

关键词： rip currents irregular bathymetry 3-D numerical modelling

Analysis of natural frequency for imaging interface in liquid lens

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Chinese Physics B 2021年第10期30卷 418-421页

作者： Na xie College of Electronic and Optical Engineering and College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210023China

Transmission beam can be modulated at the liquid-liquid interface inside an electrowetting liquid *** fluctuation characteristics of the interface has a decisive effect on the beam modulation.A closed cylinder in capillary constant scale is analyzed and the natural frequencies of a flat interface are obtained using capillary wave *** in modes 0 and 1 are in good agreement with previous experiments in the *** influences of the radius,the height ratio and the height-to-diameter ratio of a liquid lens on the interface eigenfrequencies are analyzed.

关键词： natural frequency liquid-liquid interface capillary wave liquid lens

Carbon nanotube-based CMOS transistors and integrated circuits

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Science China(Information Sciences) 2021年第10期64卷 136-151页

作者： Yunong xie Zhiyong ZHANG Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics and Center for Carbon-based Electronics Department of Electronics Peking University Academy for Advanced Interdisciplinary Studies Peking University

Over the last sixty years, the scaling of silicon-based complementary metal-oxide-semiconductor(CMOS) field-effect transistors(FETs) have promoted the rapid development of microelectronic ***, the development of Si CMOS technology is currently subject to serious challenges from various aspects such as physics limit, cost, and power consumption, and is becoming increasingly difficult. Material innovation is exerting an ever-greater role in the integrated circuit design. By looking for thinner semiconductor materials with higher mobility as the active layer to construct smaller and higher-performance transistors, it is possible to further stimulate transistors and integrated circuits on performance, density,power dissipation, and functions. In 1991, Iijima discovered carbon nanotubes(CNTs). Due to its excellent electrical properties and intrinsic nano-scale size, CNT has been considered by academia and industry to have great potential to replace silicon materials in the future for the extremely scaled technology nodes or novel electronic applications. This paper reviews the latest advancements in CNT-based electronics ***, the challenges and pathways for nanotube transistors to transition into commercial applications are discussed.

关键词： carbon nanotube transistor integrated circuit scaling nanoelectronics

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肺结核发病的时空分布特征和气象因素分析

山东理工大学学报（自然科学版） 2025年第1期39卷 41-45页

作者：谢小义汉江师范学院数学与计算机科学学院湖北十堰442000

通过对2015—2019年全国肺结核发病率数据(不含香港地区、澳门地区和台湾地区)可视化,探究全国肺结核发病的时空分布特征;通过空间自相关分析和拉格朗日乘数(LM)检验,选取面板数据空间杜宾模型探究有关气象因素对肺结核发病的影响。研... 详细信息

通过对2015—2019年全国肺结核发病率数据(不含香港地区、澳门地区和台湾地区)可视化,探究全国肺结核发病的时空分布特征;通过空间自相关分析和拉格朗日乘数(LM)检验,选取面板数据空间杜宾模型探究有关气象因素对肺结核发病的影响。研究结果表明,每年的1月和3月是全国肺结核的高发期,且全国肺结核发病率存在空间聚集性,高发区域是新疆、西藏和青海等西北部地区;气温和湿度与当地肺结核发病是负相关关系,与周边地区的肺结核发病是正相关关系。

关键词：肺结核时间流行趋势空间分布特征空间杜宾模型

Constrained Unscented Kalman Filtering for Bearings-Only Maneuvering Target Tracking

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Chinese Journal of Electronics 2020年第3期29卷 501-507页

作者： ZHANG Hongwei xie Weixin Sun Yat-sen University ATR Key Laboratory Shenzhen University

To track the bearings-only maneuvering target tracking accurately online, the soft measurement constraints are implemented into the Unscented Kalman filtering(UKF). To deal with the soft measurement constraints, the Lasso regularization is added as the obstacle function. In doing this, the sampled sigma points can be restricted into the feasible region. To enhance the sampling efficiency, the global optimal solution is acquired by a heuristic optimizer. To smooth the outliers,the posterior distribution is approximated by a Gaussian mixture consists of the original and the modified priors with the fuzzy weighted factor. Simulated results indicate the accuracy and the computational efficiency of the proposed method.

关键词： Bearings-only maneuvering target tracking Soft measurement constraints Optimal

The Weight Distribution of a Class of p-Ary Cyclic Codes with Few Weights

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Chinese Journal of Electronics 2020年第4期29卷 717-723页

作者： LIU Li xie Xianhong School of Mathematics Hefei University of Technology Key Laboratory of Electromagnetic Space Information CAS University of Science and Technology of China

In this paper, we investigate a class of p-ary cyclic codes whose duals have two zeros for some special cases and calculate their weight distributions *** results show that the codes have at most five nonzero ***, the... 详细信息

关键词： Cyclic codes Weight distributions Fourier expansion Gauss sums Griesmer bound

Gradient Wetting Transition from the Wenzel to Robust Cassie-Baxter States along Nanopillared Cicada Wing and Underlying Mechanism

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Journal of Bionic Engineering 2020年第5期17卷 1009-1018页

作者： Heng xie Hanxiong Huang Lab for Micro Molding and Polymer Rheology Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing and Key Laboratory of Polymer Processing Engineering(Ministry of Education)South China University of TechnologyGuangzhou 510640China

Gradient wettability is important for some living ***,the dynamic responses of water droplets impacting on the surfaces of four regions along the wing vein of cicada Cryptotympana atratafabricius are *** is revealed that a gradient wetting behavior from hydrophilicity(the Wenzel state)to hydrophobicity and further to superhydrophobicity(the Cassie-Baxter state)appears from the foot to apex of the *** droplets impacting on the hydrophilic region of the wing cannot rebound,whereas those impacting on the hydrophobic region can retract and completely *** hydrophobic region exhibits robust water-repelling performance during the dynamic droplet ***,a droplet sitting on the hydrophobic region can recover its spherical shape after squeezed to a water film as thin as 0.45 mm,and lossless droplet transportation can be achieved at the *** on the geometric parameters of the nanopillars at the hydrophilic and hydrophobic regions on the cicada wing,two wetting models are developed for elucidating the mechanism for the gradient wetting *** work directs the design and fabrication of surfaces with gradient wetting behavior by mimicking the nanopillars on cicada wing surface.

关键词： cicada wing nanopillared surface biomimetic gradient wetting transition dynamic wetting behavior