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Analyzing the Urban Hierarchical Structure Based on Multiple Indicators of Economy and Industry: An Econometric Study in China

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Computer Modeling in Engineering & Sciences 2022年第6期131卷 1831-1855页

作者： Jing Cheng Yang Xie Jie Zhang School of Architecture Tsinghua UniversityBeijing100084China Beijing Tsinghua Tongheng Urban Planning&Design Institute Beijing100085China

For a city,analyzing its advantages,disadvantages and the level of economic development in a country is important,especially for the cities in China developing at flying speed.The corresponding literatures for the cities in China have not considered the indicators of economy and industry in detail.In this paper,based on multiple indicators of economy and industry,the urban hierarchical structure of 285 cities above the prefecture level in China is investigated.The indicators from the economy,industry,infrastructure,medical care,population,education,culture,and employment levels are selected to establish a new indicator system for analyzing urban hierarchical structure.The factor analysis method is used to investigate the relationship between the variables of selected indicators and obtain the score of each common factor and comprehensive scores and rankings for 285 cities above the prefecture level in China.According to the comprehensive scores,285 cities above the prefecture level are clustered into 15 levels by using K-means clustering algorithm.Then,the hierarchical structure system of the cities above the prefecture level in China is obtained and corresponding policy implications are proposed.The results and implications can not only be applied to the urban planning and development in China but also offer a reference on other developing countries.The methodologies used in this paper can also be applied to study the urban hierarchical structure in other countries.

关键词： Urban planning hierarchical structure prefecture-level city factor analysis method K-means clustering algorithm China

Conceptual design and flight test of two wingtipdocked multi-body aircraft

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Chinese Journal of Aeronautics 2022年第12期35卷 144-155页

作者： yang MENG Chao AN Changchuan xie Chao yang School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China

To overcome the drawbacks such as large wing deformations,poor performance encountering gusts,limits in taking off and landing,inconvenience of transportation of High-Altitude Long-Endurance(HALE)Unmanned Aerial Vehicles(UAVs),a new conceptual aircraft called wingtip-docked Multi-Body Aircraft(MBA)has attracted lots of attentions.Aiming to investigate the feasibility of this concept,two UAV models were designed,manufactured and connected by a wingtip-docking mechanism,which only allows the relative roll motion between the two aircraft.The trim solution of the two connected aircraft is firstly obtained by solving the developed nonlinear flight dynamic equations,followed by the stability analysis based on the linearized model.The results show that the connected aircraft is inherently unstable and cannot fly without a reasonable flight control system.A set of Proportional-Integral-Derivative(PID)control laws was then developed and implemented in the two experimental aircraft.The success of the flight tests show that the flight control can effectively eliminate the unstable motion and the wingtip-docked MBA is controllable and feasible。

关键词： Flight test Multi-body aircraft New conceptual aircraft PID control Wingtip-docking mechanism

Observer design and interval estimation of time-delay discrete-time linear systems with external disturbance and measurement noise

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Control Theory and Technology 2024年第1期22卷 69-80页

作者： Junqi yang Jianhao xie Feiyang Liu School of Electrical Engineering and Automation Henan Key Laboratory of Intelligent Detection and Control of Coal Mine EquipmentHenan Polytechnic UniversityJiaozuo454003HenanChina

For a class of time-delay discrete-time linear systems with external disturbance and measurement noise, the interval estimation problems of state and measurement noise are investigated in this paper. First, the system state together with the time-delay term and measurement noise is augmented as a new state, and a singular system is then constructed. Subsequently, a kind of decoupling technique is employed to eliminate the effect of external disturbance, and an observer is designed to simultaneously estimate the system state and measurement noise. Based on the estimated state and measurement noise, the interval estimations of system state and measurement noise are obtained by reachability analysis technique. Finally, the effectiveness of the proposed method is verified by a four-tank liquid level system.

关键词： Interval estimation Time-delay system Observer design Reachability analysis

Novel structural designs of 3D-printed osteogenic graft for rapid angiogenesis

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生物设计与制造（英文） 2023年第1期6卷 51-73页

作者： Weiying Lu yang Shi Zhijian xie Stomatology Hospital School of StomatologyZhejiang University School of MedicineZhejiang UniversityHangzhou 310006China Key Laboratory of Oral Biomedical Research of Zhejiang Province Zhejiang UniversityHangzhou 310006China Cancer Center Zhejiang UniversityHangzhou 310006China Zhejiang Provincial Clinical Research Center for Oral Diseases Zhejiang UniversityHangzhou 310006China

Large bone defect regeneration has always been recognized as a challenging clinical problem due to the difficulty of revascularization.Conventional treatments exhibit certain inherent disadvantages(e.g.,secondary injury,immunization,and potential infections).However,three-dimensional(3D)printing technology as an emerging field can serve as an effective approach to achieve satisfactory revascularization while making up for the above limitations.A wide variety of methods can be used to facilitate blood supply during the design of a 3D-printed scaffold.Importantly,the scaffold structure lays a foundation for the entire printing object;any method to promote angiogenesis can be effective only if it is based on well-designed scaffolds.In this review,different designs related to angiogenesis are summarized by collecting the literature from recent years.The 3D-printed scaffolds are classified into four major categories and discussed in detail,from elementary porous scaffolds to the most advanced bone-like scaffolds.Finally,structural design suggestions to achieve rapid angiogenesis are proposed by analyzing the above architectures.This review can provide a reference for organizations or individual academics to achieve improved bone defect repair and regeneration using 3D printing.

关键词： 3D printing Angiogenesis Bone regeneration Tissue engineering Biomimetic scaffolds

Stable anode-free zinc-ion batteries enabled by alloy network-modulated zinc deposition interface

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Journal of Energy Chemistry 2023年第1期76卷 32-40,I0002页

作者： Shiyin xie yang Li Liubing Dong Collegeof Chemistry and Materials Science Jinan UniversityGuangzhou 511443GuangdongChina

Newly-proposed anode-free zinc-ion batteries(ZIBs)are promising to remarkably enhance the energy density of ZIBs,but are restricted by the unfavorable zinc deposition interface that causes poor cycling stability.Herein,we report a Cu-Zn alloy network-modulated zinc deposition interface to achieve stable anode-free ZIBs.The alloy network can not only stabilize the zinc deposition interface by suppressing 2D diffusion and corrosion reactions but also enhance zinc plating/stripping kinetics by accelerating zinc desolvation and nucleation processes.Consequently,the alloy network-modulated zinc deposition interface realizes high coulombic efficiency of 99.2%and high stability.As proof,Zn//Zn symmetric cells with the alloy network-modulated zinc deposition interface present long operation lifetimes of 1900 h at 1 m A/cm^(2)and 1200 h at 5 m A/cm^(2),significantly superior to Zn//Zn symmetric cells with unmodified zinc deposition interface(whose operation lifetime is shorter than 50 h),and meanwhile,Zn3V3O8cathodebased ZIBs with the alloy network-modified zinc anodes show notably enhanced rate capability and cycling performance than ZIBs with bare zinc anodes.As expected,the alloy network-modulated zinc deposition interface enables anode-free ZIBs with Zn3V3O8cathodes to deliver superior cycling stability,better than most currently-reported anode-free ZIBs.This work provides new thinking in constructing high-performance anode-free ZIBs and promotes the development of ZIBs.

关键词： Zinc-ion battery Zinc anode Zinc deposition interface Anode-free zinc-ion battery Cu-Zn alloy network

High Order Mixed Finite Elements with Mass Lumping for Elasticity on Triangular Grids

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Numerical Mathematics(Theory,Methods and Applications) 2022年第1期15卷 227-250页

作者： Yan yang Xiaoping xie School of Sciences Southwest Petroleum UniversityChengdu 610500China School of Mathematics Sichuan UniversityChengdu 610064China

A family of conforming mixed finite elements with mass lumping on triangular grids are presented for linear elasticity.The stress field is approximated by symmetric H(div)−Pk(k≥3)polynomial tensors enriched with higher order bubbles so as to allow mass lumping,and the displacement field is approximated by C−1−Pk−1 polynomial vectors enriched with higher order terms.For both the proposed mixed elements and their mass lumping schemes,optimal error estimates are derived for the stress and displacement in H(div)norm and L 2 norm,respectively.Numerical results confirm the theoretical analysis.

关键词： Linear elasticity mixed finite element mass lumping error estimate

Real-time Subsynchronous Control Interaction Monitoring Using Improved Intrinsic Time-scale Decomposition

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Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 816-826页

作者： yang Wang Hanlu yang Xiaorong xie Xiaomei yang Guanrun Chen College of Electrical Engineering Sichuan UniversityChengduChina Department of Electrical Engineering Tsinghua UniversityBeijingChina

In recent years,subsynchronous control interaction(SSCI)has frequently taken place in renewable-connected power systems.To counter this issue,utilities have been seeking tools for fast and accurate identification of SSCI events.The main challenges of SSCI monitoring are the time-varying nature and uncertain modes of SSCI events.Accordingly,this paper presents a simple but effective method that takes advantage of intrinsic time-scale decomposition(ITD).The main purpose is to improve the accuracy and robustness of ITD by incorporating the least-squares method.Results show that the proposed method strikes a good balance between dynamic performance and estimation accuracy.More importantly,the method does not require any prior information,and its performance is therefore not affected by the frequency constitution of the SSCI.Comprehensive comparative studies are conducted to demonstrate the usefulness of the method through synthetic signals,electromagnetic temporary program(EMTP)simulations,and field-recorded SSCI data.Finally,real-time simulation tests are conducted to show the feasibility of the method for real-time monitoring.

关键词： Subsynchronous control interaction(SSCI) intrinsic time-scale decomposition(ITD) wind power system realtime monitoring

A Bayesian hierarchical model for analyzing methylated RNA immunoprecipitation sequencing data

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Frontiers of Electrical and Electronic Engineering in China 2018年第3期6卷 275-286页

作者： Minzhe Zhangl Qiwei Lil Yang Xie Quantitative Biomedical Research Center Department of Clinical Sciences U.T. Southwestern Medical Center Dallas USA Department of Bioinformatics U.T. Southwestern Medical Center Dallas USA Simmons Comprehensive Cancer Center U.T. Southwestern Medical Center Dallas USA

Background： The recently emerged technology of methylated RNA immunoprecipitation sequencing （MeRIP-seq） sheds light on the study of RNA epigenetics. This new bioinformatics question calls for effective and robust peaking calling algorithms to detect mRNA methylation sites from MeRIP-seq data. Methods： We propose a Bayesian hierarchical model to detect methylation sites from MeRIP-seq data. Our modeling approach includes several important characteristics. First, it models the zero-inflated and over-dispersed counts by deploying a zero-inflated negative binomial model. Second, it incorporates a hidden Markov model （HMM） to account for the spatial dependency of neighboring read enrichment. Third, our Bayesian inference allows the proposed model to borrow strength in parameter estimation, which greatly improves the model stability when dealing with MeRIP-seq data with a small number of replicates. We use Markov chain Monte Carlo （MCMC） algorithms to simultaneously infer the model parameters in a de novo fashion. The R Shiny demo is available at https：//qiwei. shinyapps.io/BaySeqPeak and the R/C ＋＋ code is available at https：//***/liqiwei2000/BaySeqPeak. Results： In simulation studies, the proposed method outperformed the competing methods exomePeak and MeTPeak, especially when an excess of zeros were present in the data. In real MeRIP-seq data analysis, the proposed method identified methylation sites that were more consistent with biological knowledge, and had better spatial resolution compared to the other methods. Conclusions： In this study, we develop a Bayesian hierarchical model to identify methylation peaks in MeRIP-seq data. The proposed method has a competitive edge over existing methods in terms of accuracy, robustness and spatial resolution.

关键词： MeRIP-seq data RNA epigenomics Bayesian inference hidden Markov model zero-inflated negativebinomial

Guideline on Chinese Medicine Rehabilitation for Idiopathic Pulmonary Fibrosis

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World Journal of Traditional Chinese Medicine 2023年第4期9卷 475-484页

作者： Jian-Sheng Li Ming-Hang Wang Yang Xie 不详

Foreword Note:Some of the elements of this document may be the subject of patent rights.WFCMS shall not be held responsible for identifying any or all such patent rights.Main drafting organizations:Henan University of... 详细信息

关键词： Henan patent Medicine