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Optimization of inter-seasonal nitrogen allocation increases yield and resource-use efficiency in a water-limited wheat-maize cropping system in the North China Plain

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The Crop Journal 2024年第3期12卷 907-914页

作者： Xiaonan Zhou Chenghang Du Haoran Li Zhencai Sun Yifei Chen zhiqiang gao Zhigan Zhao Yinghua Zhang Zhimin Wang Ying Liu College of Agronomy and Biotechnology China Agricultural UniversityBeijing 100193China College of Information and Electrical Engineering China Agricultural UniversityBeijing 100193China Ministerial and Provincial Co-Innovation Centre for Endemic Crops Production with High-Quality and Efficiency in Loess Plateau Taigu 030801ShanxiChina

Winter wheat–summer maize cropping system in the North China Plain often experiences droughtinduced yield reduction in the wheat season and rainwater and nitrogen(N)fertilizer losses in the maize season.This study aimed to identify an optimal interseasonal water-and N-management strategy to alleviate these losses.Four ratios of allocation of 360 kg N ha^(-1)between the wheat and maize seasons under one-time presowing root-zone irrigation(W0)and additional jointing and anthesis irrigation(W2)in wheat and one irrigation after maize sowing were set as follows:N1(120:240),N2(180:180),N3(240:120)and N4(300:60).The results showed that under W0,the N3 treatment produced the highest annual yield,crop water productivity(WPC),and nitrogen partial factor productivity(PFPN).Increased N allocation in wheat under W0 improved wheat yield without affecting maize yield,as surplus nitrate after wheat harvest was retained in the topsoil layers and available for the subsequent maize.Under W2,annual yield was largest in the N2 treatment.The risk of nitrate leaching increased in W2 when N application rate in wheat exceeded that of the N2 treatment,especially in the wet year.Compared to W2N2,the W0N3 maintained 95.2%grain yield over two years.The WPCwas higher in the W0 treatment than in the W2 treatment.Therefore,following limited total N rate,an appropriate fertilizer N transfer from maize to wheat season had the potential of a“triple win”for high annual yield,WPCand PFPN in a water-limited wheat–maize cropping system.

关键词： Cropping system Water-saving irrigation North China Plain Nitrogen optimization Sustainable intensification

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On geometric interpretation of extended state observer: a preliminary study

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Control Theory and Technology 2023年第1期21卷 89-96页

作者： Jinfeng Chen zhiqiang gao Center for Advanced Control Technologies Cleveland State University2121 Euclid AvenueClevelandOH 44115USA

Borrowing the framework of the geometric approach, this paper tries to analyze and explain why it is possible for the extended state observer (ESO) to estimate the state vector and total disturbance accurately. The geometric approach has provided an elegant and rigorous framework to redefine some key concepts in modern control theory, such as controllability and observability. Moreover, those concepts can be extended to deal with systems in the presence of inaccessible disturbances, such as controlled invariants and conditioned invariants. It is shown in this paper that the augmented system of the ESO is unknown-state unknown-input completely reconstructable in finite time interval. A numerical simulation is given to verify the state vector and total disturbance can be estimated accurately by the ESO if the augmented system is unknown-state unknown-input completely reconstructable.

关键词： Extended state observer:Geometric approach-Observability Uncertain linear systems

On the notions of normality, locality, and operational stability in ADRC

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Control Theory and Technology 2023年第1期21卷 97-109页

作者： Huiyu Jin zhiqiang gao School of Aerospace Engineering Xiamen UniversityXiamen 361102FujianChina Center for Advanced Control Technologies Cleveland State UniversityClevelandOH 44115USA

Treating plant dynamics as an ideal integrator chain disturbed by the total disturbance is the hallmark of active disturbance rejection control(ADRC).To interpret its effectiveness and success,to explain why so many vastly different dynamic systems can be treated in this manner,and to answer why a detailed,accurate,and global mathematical model is unnecessary,is the target of this paper.Driven by a motivating example,the notions of normality and locality are introduced.Normality shows that,in ADRC,the plant is normalized to an integrator chain,which is called local nominal model and locally describes the plant’s frequency response in the neighborhood of the expected gain crossover frequency.Locality interprets why ADRC can design the controller only with the local information of the plant.With normality and locality,ADRC can be effective and robust,and obtain operational stability discussed by T.S.Tsien.Then viewing proportional-integral-derivative(PID)control as a low-frequency approximation of second-order linear ADRC,the above results are extended to PID control.A controller design framework is proposed to obtain the controller in three steps:(1)choose an integrator chain as the local nominal model of the plant;(2)select a controller family corresponding to the local nominal model;and(3)tune the controller to guarantee the gain crossover frequency specification.The second-order linear ADRC and the PID control are two special cases of the framework.

关键词： Active disturbance rejection control-Normality Locality Local nominal model Bode plot Operational stability Design framework

On tuning of ADRC with competing design indices:a quantitative study

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Control Theory and Technology 2023年第1期21卷 16-33页

作者： Yutao Zhao Yi Huang zhiqiang gao Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Electrical Engineering and Computer Science Center for Advanced Control TechnologiesCleveland State UniversityClevelandOH 44115USA

Controller optimization has mostly been done by minimizing a certain single cost function.In practice,however,engineers must contend with multiple and conflicting considerations,denoted as design indices(DIs)in this paper.Failure to account for such complexity and nuances is detrimental to the applications of any advanced control methods.This paper addresses this challenge heads on,in the context of active disturbance rejection controller(ADRC)and with four competing DIs:stability margins,tracking,disturbance rejection,and noise suppression.To this end,the lower bound for the bandwidth of the extended state observer is first established for guaranteed closed-loop stability.Then,one by one,the mathematical formula is meticulously derived,connecting each DI to the set of controller parameters.To our best knowledge,this has not been done in the context of ADRC.Such formulas allow engineers to see quantitatively how the change of each tuning parameter would impact all of the DIs,thus making the guesswork obsolete.An example is given to show how such analytical methods can help engineers quickly determine controller parameters in a practical scenario.

关键词： Uncertain systems Active disturbance rejection control(ADRC) Design indices(DIs) Extended state observer(ESO)

Connecting theory and practice with ADRC

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Control Theory and Technology 2023年第1期21卷 1-3页

作者： zhiqiang gao Yi Huang Center for Advanced Control Technologies Cleveland State UniversityClevelandUSA Key Laboratory of Systems and Control Chinese Academy of SciencesBeijingChina

From Qiang Xuesen[1],to Guan Zhaozhi[2],and finally to Han Jingqing[3],active disturbance rejection control(ADRC)arose from their unwavering conviction that theory must be connected to practice,and that control theory of any practical significance must not simply be a branch of mathematics,predicated on accurate mathematical model of physical processes.It is their vision and wisdom that have guided us through difficult times.

关键词： theory finally branch

On a novel tracking differentiator design based on iterative learning in a moving window

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Control Theory and Technology 2023年第1期21卷 46-55页

作者： Xiangyang Li Rafal Madonski zhiqiang gao Senping Tian Key Laboratory of Autonomous Systems and Network Control Ministry of EducationSchool of Automation Science and EngineeringSouth China University of TechnologyGuangzhou 510641China Energy and Electricity Research Center Jinan UniversityZhuhai 519070China Department of Electrical and Computer Science Cleveland State UniversityClevelandOH 44115USA

Differential signals are key in control engineering as they anticipate future behavior of process variables and therefore are critical in formulating control laws such as proportional-integral-derivative(PID).The practical challenge,however,is to extract such signals from noisy measurements and this difficulty is addressed first by J.Han in the form of linear and nonlinear tracking differentiator(TD).While improvements were made,TD did not completely resolve the conflict between the noise sensitivity and the accuracy and timeliness of the differentiation.The two approaches proposed in this paper start with the basic linear TD,but apply iterative learning mechanism to the historical data in a moving window(MW),to form two new iterative learning tracking differentiators(IL-TD):one is a parallel IL-TD using an iterative ladder network structure which is implementable in analog circuits;the other a serial IL-TD which is implementable digitally on any computer platform.Both algorithms are validated in simulations which show that the proposed two IL-TDs have better tracking differentiation and de-noise performance compared to the existing linear TD.

关键词： Tracking differentiator(TD) Iterative learning Iterative learning tracking differentiator(IL-TD) Active disturbance rejection control(ADRC)-Two-dimensional system(2-D system)

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面神经功能评价

临床耳鼻咽喉头颈外科杂志 2024年第5期38卷 359-363页

作者：高志强中国医学科学院北京协和医院北京100010

面神经功能评价是面神经诊疗中至关重要的工作。面神经功能评价系统主要分为主观评价系统和客观评价系统。主观评价系统简便、应用广泛,但受评价者的主观影响,精准性欠佳。客观评价系统有更高的准确性和稳定性,能提供更多的量化信息。... 详细信息

面神经功能评价是面神经诊疗中至关重要的工作。面神经功能评价系统主要分为主观评价系统和客观评价系统。主观评价系统简便、应用广泛,但受评价者的主观影响,精准性欠佳。客观评价系统有更高的准确性和稳定性,能提供更多的量化信息。随着近年计算机视觉、人工智能等技术的快速发展,越来越精准、稳定且智能化的面神经评价系统逐渐走向临床应用。在选择具体的面神经评价系统时需综合临床场景、评价目的、患者特点等因素进行选择。

关键词：面神经功能评价人工智能

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Precise asymptotics in limit theorems for a supercritical branching process with immigration in a random environment

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Acta Mathematica Sinica,English Series 2023年

作者： Chunmao HUANG Rui ZHANG zhiqiang gao Harbin Institute of Technology (Weihai) Department of Mathematics Beijing Normal University School of Mathematical Sciences

Let(Zn) be a supercritical branching process with immigration in an independent and identically distributed random environment. Under necessary moment conditions, we show the exact convergence rate in the central limit theorem on log Znand establish the corresponding local limit theorem by using the moments of the natural submartingale and the convergence rates of its logarithm.By similar approach and with the help of a change of measure, we also present the so-called integrolocal theorem and integral large deviation theorem to characterize the precise asymptotics of the upper large deviations.

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Engineering cybernetics: 60 years in the making

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Control Theory and Technology 2014年第2期12卷 97-109页

作者： zhiqiang gao Center for Advanced Control Technologies Cleveland State University

The landmark book of Hsue-Shen Tsien, ＇Engineering Cybernetics＇, gave birth 60 years ago to an engineering science of interrelations and synthetic behaviors. Clothing the bare bones of Norbert Wiener＇s conception of cybernetics, the book delineates for the new science the requirement （of having direct impacts on engineering applications）, the aim （of encapsulating engLneering principles and concepts）, the problems （of analysis, design, and uncertainty）, the tools （of basic and advanced mathematics）, and the scope （systems that are single input and output or multiple input and output, linear or nonlinear, deterministic or stochastic）. The book is a showcase of originality, critical thinking and foresights. In particular, the author calls into question the basic assumption that ＇the properties and characteristics of the system to be controlled were always assumed to be known＇ and points out that, in reality, ＇large unpredictable variations of the system properties may occur＇. Sixty years later, the full spectrum of Tsien＇s prophetic ideas is yet to be fully grasped and engineering cybernetics, as Tsien envisioned, is still in the making.

关键词： Cybernetics Engineering cybernetics Engineering science Feedback Active disturbance rejection

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