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Open-loop and closed-loop D^(α)-type iterative learning control for fractional-order linear multi-agent systems with state-delays

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Journal of Systems Engineering and Electronics 2021年第1期32卷 197-208页

作者： LI Bingqiang lan tianyi ZHAO Yiyun LYU Shuaishuai School of Automation Northwestern Polytechnical UniversityXi’an 710129China School of Electrical and Control Engineering Shaanxi University of Science and TechnologyXi’an 710021China College of Electronics and Information Hangzhou Dianzi UniversityHangzhou 310018China

This study focuses on implementing consensus tracking using both open-loop and closed-loop Dα-type iterative learning control(ILC)schemes,for fractional-order multi-agent systems(FOMASs)with *** desired trajectory is constructed by introducing a virtual leader,and the fixed communication topology is considered and only a subset of followers can access the desired *** each control scheme,one controller is designed for one agent *** to the tracking error between the agent and the virtual leader,and the tracking errors between the agent and neighboring agents during the last iteration(for open-loop scheme)or the current running(for closed-loop scheme),each controller continuously corrects the last control law by a combination of communication weights in the topology to obtain the ideal control *** the rigorous analysis,sufficient conditions for both control schemes are established to ensure that all agents can achieve the asymptotically consistent output along the iteration axis within a finite-time *** numerical simulation results demonstrate the effectiveness of the control schemes,and provide some meaningful comparison results.

关键词： multi-agent system fractional-order consensus control iterative learning control virtual leader state-delay

Nutrition strategies to control post-weaning diarrhea of piglets: From the perspective of feeds

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Animal Nutrition 2024年第2期17卷 297-311页

作者： Qingsong Tang tianyi lan Chengyu Zhou Jingchun Gao Liuting Wu Haiyang Wei Wenxue Li Zhiru Tang Wenjie Tang Hui Diao Yetong Xu Xie Peng Jiaman Pang Xuan Zhao Zhihong Sun Laboratory for Bio-Feed and Molecular Nutrition College of Animal Science and Technology Southwest University Animal Breeding and Genetics Key Laboratory of Sichuan Province Sichuan Animal Science Academy Yibin Academy of Southwest University

Post-weaning diarrhea(PWD) is a globally significant threat to the swine industry. Historically, antibiotics as well as high doses of zinc oxide and copper sulfate have been commonly used to control ***, the development of bacterial resistance and environmental pollution have created an interest in alternative strategies. In recent years, the research surrounding these alternative strategies and the mechanisms of piglet diarrhea has been continually updated. Mechanically, diarrhea in piglets is a result of an imbalance in intestinal fluid and electrolyte absorption and secretion. In general, enterotoxigenic Escherichia coli(ETEC) and diarrheal viruses are known to cause an imbalance in the absorption and secretion of intestinal fluids and electrolytes in piglets, resulting in diarrhea when Cl secretion-driven fluid secretion surpasses absorptive capacity. From a perspective of feedstuffs, factors that contribute to imbalances in fluid absorption and secretion in the intestines of weaned piglets include high levels of crude protein(CP), stimulation by certain antigenic proteins, high acid-binding capacity(ABC), and contamination with deoxynivalenol(DON) in the diet. In response, efforts to reduce CP levels in diets,select feedstuffs with lower ABC values, and process feedstuffs using physical, chemical, and biological approaches are important strategies for alleviating PWD in piglets. Additionally, the diet supplementation with additives such as vitamins and natural products can also play a role in reducing the diarrhea incidence in weaned piglets. Here, we examine the mechanisms of absorption and secretion of intestinal fluids and electrolytes in piglets, summarize nutritional strategies to control PWD in piglets from the perspective of feeds, and provide new insights towards future research directions.

关键词： Post-weaning diarrhea Fluid secretion Feed Nutritional regulation strategies Piglet

Spectrum evolution of Rayleigh backscattering in one‐dimensional waveguide

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Opto-Electronic Advances 2019年第8期2卷 2-8页

作者： Fuhui Li tianyi lan Ligang Huang Iroegbu Paul Ikechukwu Wuming Liu Tao Zhu Key Laboratory of Optoelectronic Technology and Systems(Education Ministry of China) Chongqing UniversityChongqing 400044China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Despite the tremendous awareness of Rayleigh scattering characteristics and its considerable research interest for numerous fields,no report has been documented on the dynamic characteristics of spectrum evolution(SpE)and physical law for Rayleigh scattering from a micro ***,the dynamic characteristics of the SpE of Rayleigh scattering in a one-dimensional waveguide(ODW)is investigated based on the quantum theory and a SpE-model of Rayleigh backscattering(RBS)source is *** means of simulation,the evolution law which represents the dynamic process of the spectrum linewidth at a state of continuous scattering is revealed,which is consistent with our previous experimental ***,an approximate theoretical prediction of the existing relationship between the spectrum linewidth of RBS source and the transmission length in ODW is proposed,which theoretically provides the feasibility of constructing functional devices suitable to ascertain laser linewidth *** designed experimental scheme can be implemented provided the assumptions are *** addition,a theoretical model of the micro-cavity structure to realize the deep compression of laser linewidth is proposed.

关键词： scattering Rayleigh spectrum evolution linewidth functional device

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区间可调节的变增益加速迭代学习控制

系统工程与电子技术 2017年第4期39卷 883-887页

作者：兰天一林辉西北工业大学自动化学院陕西西安710129

为加快迭代学习控制律的收敛速度,针对线性时不变系统,以P-型、D-型学习律为例,提出了区间可调节的、具有指数加速、含反馈信息的迭代学习控制算法。首先,根据每次学习效果,确定下一次迭代需要修正的区间并在该区间内修正控制律增益;其... 详细信息

为加快迭代学习控制律的收敛速度,针对线性时不变系统,以P-型、D-型学习律为例,提出了区间可调节的、具有指数加速、含反馈信息的迭代学习控制算法。首先,根据每次学习效果,确定下一次迭代需要修正的区间并在该区间内修正控制律增益;其次,分析了所提算法的收敛性并给出其收敛条件;最后,理论结果表明收敛速度主要取决于被控对象、控制律增益、修正指数和学习区间的大小。相同仿真条件下,与传统算法相比,所提算法具有更快的收敛速度。

关键词：迭代学习控制单调收敛收敛速度加速学习

Ultra-high spectral purity laser derived from weak external distributed perturbation

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Opto-Electronic Advances 2023年第2期6卷 39-48页

作者： Laiyang Dang Ligang Huang Leilei Shi Fuhui Li Guolu Yin Lei Gao tianyi lan Yujia Li Lidan Jiang Tao Zhu Key Laboratory of Optoelectronic Technology and Systems(Education Ministry of China) Chongqing UniversityChongqing 400044China

Ultra-high spectral purity lasers are of considerable research interests in numerous fields such as coherent optical communication,microwave photonics,distributed optical fiber sensing,gravitational wave detection,optical clock,and so ***,to deeply purify laser spectrum with compact size under normal condition,we propose a novel and practical idea to effectively suppress the spontaneous radiation of the laser cavity through weak external distributed ***,a laser configuration consisting of a main lasing cavity and an external distributed feedback cavity is *** feedback signal with continuous spatio-temporal phase transition controlled by a distributed feedback structure is injected into the main cavity,which can deeply suppress the coupling rate from the spontaneous radiation to the stimulated emission and extremely purify the laser ***,an ultra-narrow linewidth on-chip laser system with a side mode suppression ratio greater than 80 dB,an output linewidth of 10 Hz,and a relative intensity noise less than-150 dB/Hz is successfully obtained under normal *** proposed concept in this work provides a new perspective for extreme regulation of laser parameters by using weak external distributed perturbation,which can be valid for various gain-type lasers with wide wavelength bands.

关键词： high-coherence weak external distributed perturbation narrow linewidth laser

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东北地区稻谷储藏期间脂肪酸含量的预测模型

农业工程学报 2020年第6期36卷 269-275页

作者：王启阳吴文福兰天忆吉林大学生物与农业工程学院长春130022

粮食储备是保障国家粮食安全的重要物质基础,谷物中脂肪酸含量是粮食储藏过程中品质变化的敏感性指标。为了实现绿色储粮安全管理,该文采用多元线性回归(multiple linear regression,MLR)、人工神经网络(artificial neural network, ANN... 详细信息

粮食储备是保障国家粮食安全的重要物质基础,谷物中脂肪酸含量是粮食储藏过程中品质变化的敏感性指标。为了实现绿色储粮安全管理,该文采用多元线性回归(multiple linear regression,MLR)、人工神经网络(artificial neural network, ANN)、支持向量回归(support vector regression, SVR)、最小二乘支持向量回归(least square support vector regression,LSSVR)等机器学习算法模型,对东北地区稻谷储藏过程中的脂肪酸含量(以KOH计)进行预测。通过主成分分析(principal component analysis,PCA)方法筛选稻谷关键储藏参数,得到4个影响稻谷脂肪酸含量的关键因子,分别为稻谷入仓水分、入仓脂肪酸含量、储藏有效积温、检测粮温。然后,将得到的关键因子进行归一化处理,再分别输入到MLR、ANN、SVR、LSSVR模型,采用决定系数R2、平均绝对误差(MAE)、平均绝对百分比误差(MAPE)、均方根误差(RMSE)等评价指标对不同模型的预测性能进行对比,探讨稻谷脂肪酸含量预测的最优模型算法。研究结果表明,LSSVR模型的决定系数R2、MAE、MAPE、RMSE分别为0.911、0.275 mg/100 g、1.604%、0.348 mg/100 g,预测效果略优于MLR,明显优于ANN和SVR,LSSVR和MLR模型可作为稻谷储藏期间脂肪酸含量预测的方法。该研究实现了稻谷脂肪酸含量的预测,为科学储粮、安全绿色储粮提供参考。

关键词：储藏脂肪酸模型稻谷机器学习算法

石英灯辐射式气动热实验的分数阶迭代学习控制策略

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西北工业大学学报 2017年第1期35卷 26-31页

作者：兰天一林辉张克军西北工业大学自动化学院陕西西安710129 西北工业大学理学院陕西西安710129

气动热实验是一种在地面上模拟考核飞行热环境下飞行器性能的有效手段。为提高实验中谱线跟踪性能,根据谱线的固定不变特性,利用分数阶迭代学习控制策略进行模拟实验。通过严格的理论分析,给出了分数阶PD~α型迭代学习控制器的收敛条件... 详细信息

气动热实验是一种在地面上模拟考核飞行热环境下飞行器性能的有效手段。为提高实验中谱线跟踪性能,根据谱线的固定不变特性,利用分数阶迭代学习控制策略进行模拟实验。通过严格的理论分析,给出了分数阶PD~α型迭代学习控制器的收敛条件,并在此理论意义下进行谱线跟踪实验。实验结果表明:所提控制算法具有较小的动态控制误差和稳态控制误差,且缩短了实验过程中谱线的调试时间,提高了实验的有效性。

关键词：气动热控制器石英灯辐射截止频率迭代学习控制试验分析

英汉双语者二语口语产生中音韵编码过程的同化机制

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心理学报 2020年第12期52卷 1377-1392页

作者：辛昕兰天一张清芳中国人民大学心理学系北京100872

本研究运用事件相关电位技术,结合时空微态分割分析法,考察英汉双语者二语口语产生过程中音韵编码过程的同化与顺应机制。研究中采用图词干扰即时命名任务,比较英汉双语者的汉语产生过程中音韵编码的加工单元与汉语母语者的汉语产生过... 详细信息

本研究运用事件相关电位技术,结合时空微态分割分析法,考察英汉双语者二语口语产生过程中音韵编码过程的同化与顺应机制。研究中采用图词干扰即时命名任务,比较英汉双语者的汉语产生过程中音韵编码的加工单元与汉语母语者的汉语产生过程还是与英语母语者的英语产生过程的特点类似。反应时结果发现汉汉组、英汉组与英英组都出现显著的音节效应。事件相关电位的结果发现英汉双语者的汉语产生过程中出现了音素效应,与其英语产生过程的特点类似,音素效应在英语和汉语的产生过程中都出现在图画呈现后的200~250 ms之间,而汉语母语者的汉语产生过程中仅发现了音节效应,出现在250~300 ms之间。时空微态分割分析发现英汉双语者在汉语产生的音韵编码过程与英语母语者在英语产生过程所对应的脑电微态成分相同,仅在持续时间上存在显著差异;其微态成分不同于汉语母语者的汉语产生过程。上述结果表明英汉双语者汉语产生的音韵编码过程与英语作为母语时的产生过程相似,而与汉语作为母语时的产生过程不同。英汉双语者的汉语产生过程采用了母语同化机制。

关键词：双语者音韵编码同化顺应

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新航天时代的回顾与展望

航天员 2019年第4期 29-33页

作者：蓝天翼不详

今年是美国首次登月的50周年纪念。整个七月,美国乃至世界的各大媒体都在极力渲染半个世纪前的那次伟大成就。回想20世纪50年代,当整个世界都处在二战后的重建过程的时候,美苏的太空竞赛拉响了,阿波罗11号就像是那次太空竞赛最好的注脚... 详细信息

今年是美国首次登月的50周年纪念。整个七月,美国乃至世界的各大媒体都在极力渲染半个世纪前的那次伟大成就。回想20世纪50年代,当整个世界都处在二战后的重建过程的时候,美苏的太空竞赛拉响了,阿波罗11号就像是那次太空竞赛最好的注脚,牢牢地标记了美国的一次重要胜利。

关键词：展望航天太空竞赛重建过程美国阿波罗世界登月