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Uncoupled PID Control of Coupled Multi-Agent Nonlinear Uncertain Systems

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Journal of Systems Science & Complexity 2018年第1期31卷 4-21页

作者： yuan Shuo ZHAO cheng GUO Lei LSC Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China. School of Mathematical Sciences University of Chinese Academy of Sciences Beijing 100049 China LSC Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

In this paper, PID（proportional-integral-derivative） controllers will be designed to solve the tracking problem for a class of coupled multi-agent systems, where each agent is described by a second-order high-dimensional nonlinear uncertain dynamical system, which only has access to its own tracking error information and does not need to communicate with others. This paper will show that a 3-dimensional manifold can be constructed based on the information about the Lipschitz constants of the system nonlinear dynamics, such that whenever the three parameters of each PID controller are chosen from the manifold, the whole multi-agent system can be stabilized globally and the tracking error of each agent approaches to zero asymptotically. For a class of coupled first-order multi-agent nonlinear uncertain systems, a PI controller will be designed to stabilize the whole system.

关键词： Coupled multi-agent system global stability Lipschitz condition nonlinear uncertain dynamics PID controller

Mapping impervious surfaces with a hierarchical spectral mixture analysis incorporating endmember spatial distribution

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Geo-Spatial Information Science 2022年第4期25卷 550-567页

作者： Zhenfeng Shao yuan Zhang cheng Zhang Xiao Huang Tao cheng State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhanChina Department of Geosciences University of ArkansasFayettevilleARUSA

Impervious surface mapping is essential for urban environmental *** Mixture Analysis(SMA)and its extensions are widely employed in impervious surface estimation from medium-resolution *** SMA,inappropriate endmember combinations and inadequate endmember classes have been recognized as the primary reasons for estimation ***,the spectral-only SMA,without considering urban spatial distribution,fails to consider spectral variability in an adequate *** lack of endmember class diversity and their spatial variations lead to over/*** mitigate these issues,this study integrates a hierarchical strategy and spatially varied endmember spectra to map impervious surface abundance,taking Wuhan and Wuzhou as two study ***,the piecewise convex multiple-model endmember detection algorithm is applied to automatically hierarch-ize images into three regions,and distinct endmember combinations are independently developed in each ***,spatially varied endmember spectra are synthesized through neighboring spectra using the distance-based *** analysis indicates that the proposed method achieves better performance than Hierarchical SMA and Fixed Four-endmembers SMA in terms of MAE,SE,and *** analysis suggests that the hierarch-ical strategy can expand endmember class types and considerably improve the performance for the study areas in general,specifically in less developed ***,we find that spatially varied endmember spectra facilitate the reduction of heterogeneous surface material variations and achieve the improved performance in developed areas.

关键词： Impervious surface Spectral Mixture Analysis(SMA) hierarchical strategy endmember class spatially varied endmember spectra

Accreting CO material onto ONe white dwarfs towards accretion-induced collapse

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Research in Astronomy and Astrophysics 2018年第3期18卷 121-128页

作者： cheng-yuan Wu Bo Wang Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China University of Chinese Academy of Sciences Beijing 100049 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 China

The final outcomes of accreting ONe white dwarfs（ONe WDs） have been studied for several decades,but there are still some issues that are not resolved. Recently,some studies suggested that the deflagration of oxygen would occur for accreting ONe WDs with Chandrasekhar masses. In this paper,we aim to investigate whether ONe WDs can experience accretion-induced collapse（AIC） or explosions when their masses approach the Chandrasekhar limit. Employing the stellar evolution code Modules for Experiments in Stellar Astrophysics（MESA）,we simulate the longterm evolution of ONe WDs with accreting CO material. The ONe WDs undergo weak multicycle carbon flashes during the mass-accretion process,leading to mass increase of the WDs. We found that different initial WD masses and mass-accretion rates influence the evolution of central density and temperature. However,the central temperature cannot reach the explosive oxygen ignition temperature due to neutrino cooling. This work implies that the final outcome of accreting ONe WDs is electroncapture induced collapse rather than thermonuclear explosion.

关键词： stars evolution - binaries close - supernovae general - white dwarfs

Treatment of desizing wastewater from the textile industry by wet air oxidation

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Journal of Environmental Sciences 2000年第3期12卷 290-295页

作者： LEI Le-cheng SUN yuan Department of Environmental Science and Engineering College of Chemical EngineeringZhejiang UniversityHangzhou 310027China.

This paper describes the application of wet air oxidation to the treatment of desizing wastewater from two textile companies. A two\|liter high temperature, high pressure autoclave reactor was used in the study. The range of operating temperatures examined was between 150 and 290℃, and the partial pressure of oxygen ranged from 0.375 to 2.25 MPa. Variations in pH, COD Cr and TOD content were monitored during each experiment and used to assess the extent of conversion of the process. The effects of temperature, pressure and reaction time were explored extensively. More than 90% COD Cr reduction and 80% TOC removal have been obtained. The results have also been demonstrated that WAO is a suitable pre\|treatment methods due to improvement of the BOD\-5/COD\-\{Cr\} ratio of desizing wastewater. The reaction kinetics of wet air oxidation of desizing wastewater has been proved to be two steps, a fast reaction followed by a slow reaction stage.

关键词： wet air oxidation wastewater treatment textile wastewater

Meningeal Lymphatic Vessels:A Drain of the Brain Involved in Neurodegeneration?

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Neuroscience Bulletin 2020年第5期36卷 557-560页

作者： yuan cheng Yan-Jiang Wang Department of Neurology and Center for Clinical Neuroscience Daping HospitalThird Military Medical UniversityChongqing 400042China Chongqing Key Laboratory of Aging and Brain Diseases Chongqing 400042.China The Institute of Brain and Intelligence Third Military Medical UniversityChongqing 400042China

Neurodegenerative diseases include several kinds of neurological disorder that are caused by the progressive death of neurons in different regions of the *** diseases affect millions of people worldwide and impose a heavy health burden on modern ***,their pathogenesis remains elusive,and disease-modifying methods are not currently available to prevent,halt,or reverse them[1].

关键词： degeneration diseases death

Reconstructing early transmission networks of SARS-CoV-2 using a genomic mutation model

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Zoological Research 2023年第3期44卷 494-504页

作者： Chao-yuan cheng Zhi-Bin Zhang State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China

The coronavirus disease 2019(COVID-19)pandemic has greatly damaged human society,but the origins and early transmission patterns of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)pathogen remain ***,we reconstructed the transmission networks of SARS-CoV-2 during the first three and six months since its first report based on ancestor-offspring relationships using BANAL-52-referenced *** explored the position(i.e.,root,middle,or tip)of early detected samples in the evolutionary tree of *** total,6799 transmission chains and 1766 transmission networks were reconstructed,with chain lengths ranging from 1-9 *** root node samples of the 1766 transmission networks were from 58 countries or regions and showed no common ancestor,indicating the occurrence of many independent or parallel transmissions of SARS-CoV-2 when first detected(i.e.,all samples were located at the tip position of the evolutionary tree).No root node sample was found in any sample(n=31,all from the Chinese mainland)collected in the first 15 days from 24 December *** using six-month data or RaTG13-referenced mutation data were *** reconstruction method was verified using a simulation *** results suggest that SARS-CoV-2 may have already been spreading independently worldwide before the outbreak of COVID-19 in Wuhan,***,a comprehensive global survey of human and animal samples is essential to explore the origins of SARS-CoV-2 and its natural reservoirs and hosts.

关键词： SARS-CoV-2 Transmission chain Transmission network Ancestor-offspring relationship De novo mutation Back mutation Secondary mutation

Fluorescence Microscopic Image Analysis of Nucleic Acids Based on The Capillary Flow Directed Assembly Ring of Neutral Red-nucleic Acid Supramolecular Complexes

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Chemical Research in Chinese Universities 2003年第3期19卷 275-279页

作者： LI yuan fang HUANG cheng zhi Laboratory of Supramolecular Chemistry and Biomedical Analysis College of Chemistry and Chemical EngineeringSouthwest Normal UniversityChongqing 400715P.R.China

It is critical to establish a direct and precise method with a high sensitivity and selectivity in analytical chemistry. In this research, making use of a well known phenomenon of capillary flow, we have proposed an image analysis method of nucleic acids at the price of a small amount of sample. When a droplet of the supramolecular complex solution, formed by neutral red and nucleic acids(NA) under an approximate neutral condition, was placed on the hydrophobic surface of dimethyl dichlorosilane pretreated glass slides, and it was evaporated, the supramolecular complex exhibited the periphery of the droplet due to the capillary effect, and accumulated there to form a red capillary flow directed assembly ring(CFDAR). A typical CFDAR has an outer diameter of (2 r ) about 1.18 mm and a ring width(2 δ ) of about 41 μm. Depending on the experimental conditions, a variety of CFDAR can be assembled. The experimental results are in agreement with our former theoretical discussion. It was found that when a droplet volume is 0.1 μL, the fluorescence intensity of the CFDAR formed by the NR NA is in proportion to the content of calf thymus DNA in the range of 0-0.28 ng, fish sperm DNA of 0-0.24 ng and yeast RNA of 0-0.16 ng with the limit of detection(3 σ ) of 1 7, 1.4 and 0.9 pg, respectively for the three nucleic acids.

关键词： Nuclei acids(NA) Neutral red(NR) Ring assembly Solid support surface Fluorescence imaging analysis

A Simulation Experiment of a Pipeline Based on Machine Learning for Neutral Hydrogen Intensity Mapping Surveys

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Research in Astronomy and Astrophysics 2022年第11期22卷 61-68页

作者： Lin-cheng Li yuan-Gen Wang School of Computer Science and Cyber Engineering Guangzhou UniversityGuangzhou 510006China

We present a simulation experiment of a pipeline based on machine learning algorithms for neutral hydrogen(H I)intensity mapping(IM)surveys with different *** simulation is conducted on H I signals,foreground emission,thermal noise from instruments,strong radio frequency interference(s RFI),and mild RFI(m RFI).We apply the Mini-Batch K-Means algorithm to identify s RFI,and Adam algorithm to remove foregrounds and m *** show that there exists a threshold of the s RFI amplitudes above which the performance of our pipeline enhances *** removing foregrounds and m RFI,the performance of our pipeline is shown to have little dependence on the apertures of *** addition,the results show that there are thresholds of the signal amplitudes from which the performance of our pipeline begins to change *** consider all these thresholds as the edges of the signal amplitude ranges in which our pipeline can function *** work,for the first time,explores the feasibility of applying machine learning algorithms in the pipeline of IM surveys,especially for large surveys with the next-generation telescopes.

关键词： cosmology:observations methods:statistical radio lines:galaxies

Distributed solving Sylvester equations with fractional order dynamics

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Control Theory and Technology 2021年第2期19卷 249-259页

作者： Songsong cheng Shu Liang yuan Fan Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education School of Electrical Engineering and AutomationAnhui UniversityHefei230601AnhuiChina Key Laboratory of Knowledge Automation for Industrial Processes of Ministry of Education School of Automation and Electrical EngineeringUniversity of Science and Technology BeijingBeijing100083China

This paper addresses distributed computation Sylvester equations of the form AX+XB=C with fractional order *** partitioning parameter matrices A,B and C,we transfer the problem of distributed solving Sylvester equations as two distributed optimization models and design two fractional order continuous-time algorithms,which have more design freedom and have potential to obtain better convergence performance than that of existing first order ***,rewriting distributed algorithms as corresponding frequency distributed models,we design Lyapunov functions and prove that proposed algorithms asymptotically converge to an exact or least squares ***,we validate the effectiveness of proposed algorithms by providing a numerical example.

关键词： Fractional order calculus Distributed optimization Sylvester equation Frequency distributed model Convergence