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Observer-Based Adaptive Fuzzy Tracking Control Using Integral Barrier Lyapunov Functionals for A Nonlinear System With Full State Constraints

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IEEE/CAA Journal of Automatica Sinica 2021年第3期8卷 617-627页

作者： Wei zhao Yanjun Liu Lei Liu School of Electrical Engineering Liaoning University of TechnologyJinzhou 121001China College of Science Liaoning University of TechnologyJinzhou 121001China

A new fuzzy adaptive control method is proposed for a class of strict feedback nonlinear systems with immeasurable states and full *** fuzzy logic system is used to design the approximator,which deals with uncertain and continuous functions in the process of backstepping *** use of an integral barrier Lyapunov function not only ensures that all states are within the bounds of the constraint,but also mixes the states and errors to directly constrain the state,reducing the conservativeness of the constraint satisfaction *** that the states in most nonlinear systems are immeasurable,a fuzzy adaptive states observer is constructed to estimate the unknown *** with adaptive backstepping technique,an adaptive fuzzy output feedback control method is *** proposed control method ensures that all signals in the closed-loop system are bounded,and that the tracking error converges to a bounded tight set without violating the full state *** simulation results prove the effectiveness of the proposed control scheme.

关键词： Adaptive control backstepping design integral barrier Lyapunov function(iBLF) states observer

AR assistance for efficient dynamic target search

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Computational Visual Media 2023年第1期9卷 177-194页

作者： Zixiang zhao Jian Wu Lili Wang State key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijingChina

When searching for a dynamic target in an unknown real world scene,search efficiency is greatly reduced if users lack information about the spatial structure of the *** target search studies,especially in robotics,focus on determining either the shortest path when the target’s position is known,or a strategy to find the target as quickly as possible when the target’s position is ***,the target’s position is often known intermittently in the real world,e.g.,in the case of using surveillance *** goal is to help user find a dynamic target efficiently in the real world when the target’s position is intermittently *** order to achieve this purpose,we have designed an AR guidance assistance system to provide optimal current directional guidance to users,based on searching a prediction *** assume that a certain number of depth cameras are fixed in a real scene to obtain dynamic target’s *** system automatically analyzes all possible meetings between the user and the target,and generates optimal directional guidance to help the user catch up with the target.A user study was used to evaluate our method,and its results showed that compared to free search and a top-view method,our method significantly improves target search efficiency.

关键词： augmented reality(AR) search guidance

Data-driven intelligent modeling framework for the steam cracking process

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Chinese Journal of Chemical Engineering 2023年第9期61卷 237-247页

作者： Qiming zhao kexin Bi Tong Qiu Department of Chemical Engineering Tsinghua UniversityBeijing 100084China Beijing key Laboratory of Industrial Big Data Systems and Applications Tsinghua UniversityBeijing 100084China School of Chemical Engineering Sichuan UniversitySichuan 610065China Department of Bioprocess Engineering Institute of BiotechnologyTechnische Universität BerlinBerlin 10623Germany

Steam cracking is the dominant technology for producing light olefins,which are believed to be the foundation of the chemical *** models of the cracking process can boost production efficiency and profit *** advancements in machine learning research have recently enabled data-driven solutions to usher in a new era of process ***,its practical application to steam cracking is still hindered by the trade-off between prediction accuracy and computational *** research presents a framework for data-driven intelligent modeling of the steam cracking *** data preparation and feature engineering techniques provide computational-ready datasets for the framework,and feedstock similarities are exploited using k-means *** propose LArge-Residuals-Deletion Multivariate Adaptive Regression Spline(LARD-MARS),a modeling approach that explicitly generates output formulas and eliminates potentially outlying *** framework is validated further by the presentation of clustering results,the explanation of variable importance,and the testing and comparison of model performance.

关键词： Mathematical modeling Data-driven modeling Process systems Steam cracking Clustering Multivariate adaptive regression spline

An economic analysis of twenty light olefin production pathways

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Journal of Energy Chemistry 2021年第5期30卷 193-202页

作者： Zhitong zhao Jingyang Jiang Feng Wang State key Laboratory of Fine Chemicals College of ChemistryFaculty of Chemical Environmental and Biological Science and TechnologyDalian University of TechnologyDalian 116024LiaoningChina State key Laboratory of Catalysis Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

A comprehensive economic analysis of twenty light olefin production pathways has been performed,covering current and promising processes from fossil(petroleum,coal and natural gas)and renewable resources(biomass and CO_(2)).Taking steam cracking of naphtha as the benchmark,this study gives an economic perspective and points out the bottleneck in different olefin production *** assessment indicates that nearly all renewable pathways are economically unattractive currently and the raw material cost accounts for dominant contribution in most pathways,especially in the oil-,natural gas-and CO_(2)-derived *** the ways of methanol-to-olefins and methanol-to-propylene,fossil pathways are cost-competitive according to the date of current Chinese market ***,the price of feedstock hydrogen needs to be lowered by 55%to fill the cost gap between CO_(2)-derived pathways and the *** the ways of oxidative coupling of methane and Fischer-Tropsch synthesis to olefins,fossil pathways enable cost-competitive processes by feedstock price fall,but further process improvement is required to approach benchmark in renewable ***,a decrease in ethanol price by45%can make ethanol dehydration pathway *** addition,costs can reduce by 4%-23%in different pathways as the production scales expand from 100 to 1000 kt/a,resulting in a change from high cost to economic profit for some of the *** results quantify the need for improvements on feedstock price,scale size and process improvement to achieve competitive production costs.

关键词： Ethylene Propylene Olefin Techno-economic Conceptual design

基于色散光学模型的^(40)Ca核子散射数据计算

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物理学报 2023年第22期72卷 111-116页

作者：赵岫鸟杜文青渤海大学物理科学与技术学院锦州121013

对钙同位素核数据的研究具有重要的理论价值和应用前景,其中^(40)Ca作为天然钙最主要的同位素,是一种重要的材料核素.本文采用色散光学模型对球形核^(40)Ca的核子弹性散射数据进行计算.通过考虑色散光学模型势中实部势的非定域性以及虚... 详细信息

对钙同位素核数据的研究具有重要的理论价值和应用前景,其中^(40)Ca作为天然钙最主要的同位素,是一种重要的材料核素.本文采用色散光学模型对球形核^(40)Ca的核子弹性散射数据进行计算.通过考虑色散光学模型势中实部势的非定域性以及虚部势的壳间隙结构,实现了对^(40)Ca相关核子散射数据的良好描述,其中包括中子总截面、核子弹性散射角分布以及分析本领.此外,本文计算了色散光学模型势的实部体积分,其随能量的变化图像在费米能附近出现了明显的色散峰结构.

关键词：核子散射色散光学模型弹性散射

STATE: A Clustering Algorithm Focusing on Edges Instead of Centers

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Chinese Journal of Electronics 2021年第5期30卷 902-908页

作者： zhao Boxiang WANG Shuliang LIU Chuanlu School of Computer Science and Technology Beijing Institute of Technology Institute of E-Government Beijing Institute of Technology

With the expansion of data scale and the increase in data complexity, it is particularly important to accurately identify clusters and efficiently save clustering results. To address this, we propose a novel clustering algorithm, Shape clustering based on data field(STATE),which can quickly identify clusters of arbitrary shapes and greatly reduce the storage space of clustering results in any datasets without reducing the accuracy. STATE mainly focuses on finding the edges of clusters and directions of edges instead of clustering centers through the data *** results of STATE are presented as the edges of clusters without data objects inside clusters and without *** experiments show that STATE can recognize complex data distribution in noisy environments without discrimination and greatly save the storage space of clustering results. When it is applied in a real-world scene,facial feature extraction, STATE can recognize eyes, nose,mouth, eyebrows and facial contours automatically without calibrating key features or training. Using the extracted facial features, we achieve facial recognition with high accuracy.

关键词： clustering algorithm focusing storage space data complexity data field complex data distribution data objects data scale pattern clustering Shape clustering edges instead face recognition feature extraction novel clustering algorithm

Feasibility Study of the GST‑SVD in Extracting the Fault Feature of Rolling Bearing under Variable Conditions

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 326-339页

作者： Xiangnan Liu Xuezhi zhao Kuanfang He School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510641China School of Mechatronic Engineering and Automation Foshan UniversityFoshan 528225China

Feature information extraction is one of the key steps in prognostics and health management of rotating *** the present study,an investigation about the feasibility of a methodology based on generalized S transform(GST)and singular value decomposition(SVD)methods for feature extraction in rolling bearing,due to local damage under variable conditions,is *** technique adopts the GST method,following the time-frequency analysis,to transform a raw fault signal of the rolling bearing into a two-dimensional complex *** then,the SVD method is performed to decompose the matrix to obtain the feature *** this procedure it is possible to obtain the fault feature information of rolling bearing under different speeds and different *** order to streamline the feature parameters of the feature vectors to train more uncomplicated models,the principal component analysis(PCA)subsequently *** particle swarm optimization-support vector machine(PSO-SVM)model is used to identify and classify the different fault states of rolling ***,in order to highlight the superiority of the proposed method some comparisons are conducted with the conventional *** obtained results show that the proposed method can effectively extract fault features of the rolling bearing under variable conditions.

关键词： Feature extraction Generalized Stockwell transform Singular value decomposition Principal component analysis

Three-stage alloying of[Ag_(44)(p-MBA)_(30)]^(4−)cluster with[Au_(2)(p-NTP)_(2)Cl]^(−)

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Nano Research 2022年第8期15卷 7742-7751页

作者： Baoyu Huang Xiaomei zhao Yong Pei Department of Chemistry Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of EducationKey Laboratory for Green Organic Synthesis and Application of Hunan ProvinceXiangtan UniversityXiangtan 411105China

Precise control of alloying sites has long been a challenge,yet little has been achieved in the atomic-level manipulation of metallic *** study reported a three-stage metal and motif exchange mechanism of alloying reaction of an atomically precise ligand-protected[Ag_(44)(p-MBA)_(30)]^(4−)(p-MBA=para-mercaptobenzoic acid)cluster with[Au_(2)(p-NTP)_(2)Cl]^(−)(p-MBA=para-mercaptobenzoic acid).During the first stage(Stage I),an exchange of ligand-shell metal atoms took *** the second stage(Stage II),the motif exchanged on the[AuAg_(43)(p-MBA)_(30)]^(4−)*** the third stage(Stage III),the Au(I)atom in the ligand-shell was swapped with a Ag(0)atom of the icosahedral *** density functional theory(DFT)calculation results demonstrated that the metal exchange proceeded via different mechanisms at the different reaction *** reaction Stages I and II,the metal exchange proceeded via formation of a dianionic[Ag_(44)(p-MBA)_(30)]^(4−)-[Au_(2)(p-NTP)_(2)Cl]^(−)intermediate and then broke and recombined with the *** Stage III,the diffusion of the Au(I)to icosahedral Ag12-core(Stage III)was proceeded via a motif catalyzed heterometal atom diffusion *** hope that this work will provide a new perspective for the precise control of alloy position in alloyed nanomaterials.

关键词： metal cluster alloying mechanism density functional theory(DFT)calculations metal exchange

Towards Rehabilitation at Home After Total Knee Replacement

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Tsinghua Science and Technology 2021年第6期26卷 791-799页

作者： wenbing zhao Shunkun Yang Xiong Luo Department of Electrical Engineering and Computer Science Cleveland State UniversityClevelandOH 44115USA School of Reliability and Systems Engineering Beihang UniversityBeijing 100191China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China

In this paper,we present the design and implementation of an avatar-based interactive system that facilitates rehabilitation for people who have received total knee replacement *** system empowers patients to carry out exercises prescribed by a clinician at the home settings more *** system helps improve accountability for both patients and *** primary sensing modality is the Microsoft Kinect sensor,which is a depth camera that comes with a Software Development Kit(SDK).The SDK provides access to 3-dimensional skeleton joint positions to software developers,which significantly reduces the challenges in developing accurate motion tracking systems,especially for use at ***,the Kinect sensor is not wellequipped to track foot orientation and its subtle *** overcome this issue,we augment the system with a commercial off-the-shelf Inertial Measurement Unit(IMU).The two sensing modalities are integrated where the Kinect serves as the primary sensing modality and the IMU is used for exercises where Kinect fails to produce accurate *** this pilot study,we experiment with four rehabilitation exercises,namely,quad set,side-lying hip abduction,straight raise leg,and ankle *** Kinect is used to assess the first three exercises,and the IMU is used to assess the ankle pump exercise.

关键词： rehabilitation physical therapy total knee replacement avatar virtual reality repetition count range of motion