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城市固废焚烧过程神经网络控制研究综述 被引量:1
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作者 汤健 田昊 +1 位作者 余文 乔俊飞 《自动化学报》 北大核心 2025年第9期1951-1973,共23页
城市固废焚烧(MSWI)已成为解决城市环境问题并实现可再生能源循环利用的主流技术,其对应系统具有参数多、耦合性强、非线性显著等特性,需采用先进过程控制技术以确保平稳高效的运行.鉴于此,进行面向MSWI过程神经网络控制(NNC)综述以弥... 城市固废焚烧(MSWI)已成为解决城市环境问题并实现可再生能源循环利用的主流技术,其对应系统具有参数多、耦合性强、非线性显著等特性,需采用先进过程控制技术以确保平稳高效的运行.鉴于此,进行面向MSWI过程神经网络控制(NNC)综述以弥补该领域的缺失和促进深入研究.首先,描述典型MSWI过程工艺,分析其控制问题与控制目标,明确控制复杂性,概述NNC及其在管理此类复杂系统方面的优势;其次,综述面向控制的机理与数据驱动焚烧炉模型;随后,简要分析和介绍非NNC控制器设计在MSWI过程的研究现状;接着,详细综述面向NNC的浅层和模糊控制器设计、网络参数、网络结构和事件触发在线更新算法以及稳定性分析的研究现状,并进行控制性能分析;然后,展望未来研究方向;最后,总结了本文在促进NNC向MSWI过程控制具身智能化发展中的贡献. 展开更多
关键词 城市固废焚烧 先进过程控制 神经网络控制 参数在线更新 结构自组织 事件驱动控制
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Reconstruction of pile-up events using a one-dimensional convolutional autoencoder for the NEDA detector array
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作者 J.M.Deltoro G.Jaworski +15 位作者 A.Goasduff V.González A.Gadea M.Palacz J.J.Valiente-Dobón J.Nyberg S.Casans A.E.Navarro-Antón E.Sanchis G.de Angelis A.Boujrad S.Coudert T.Dupasquier S.Ertürk O.Stezowski R.Wadsworth 《Nuclear Science and Techniques》 2025年第2期62-70,共9页
Pulse pile-up is a problem in nuclear spectroscopy and nuclear reaction studies that occurs when two pulses overlap and distort each other,degrading the quality of energy and timing information.Different methods have ... Pulse pile-up is a problem in nuclear spectroscopy and nuclear reaction studies that occurs when two pulses overlap and distort each other,degrading the quality of energy and timing information.Different methods have been used for pile-up rejection,both digital and analogue,but some pile-up events may contain pulses of interest and need to be reconstructed.The paper proposes a new method for reconstructing pile-up events acquired with a neutron detector array(NEDA)using an one-dimensional convolutional autoencoder(1D-CAE).The datasets for training and testing the 1D-CAE are created from data acquired from the NEDA.The new pile-up signal reconstruction method is evaluated from the point of view of how similar the reconstructed signals are to the original ones.Furthermore,it is analysed considering the result of the neutron-gamma discrimination based on charge comparison,comparing the result obtained from original and reconstructed signals. 展开更多
关键词 1D-CAE Autoencoder CAE Convolutional neural network(CNN) Neutron detector Neutron-gamma discrimination(NGD) Machine learning Pulse shape discrimination Pile-up pulse
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Modeling and active disturbance rejection control of a tilt-rotor UAV
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作者 Victor-Gabriel Sánchez-Meza Yair Lozano-Hernández +2 位作者 Norma Lozada-Castillo Mario Ramírez-Neria Alberto Luviano-Juárez 《Control Theory and Technology》 2025年第3期563-577,共15页
In this article,the dynamical model and trajectory tracking problem for a tilt-rotor unmanned aerial vehicle is tackled through linear Active Disturbance Rejection Control(ADRC)applied on the tangent linearized system... In this article,the dynamical model and trajectory tracking problem for a tilt-rotor unmanned aerial vehicle is tackled through linear Active Disturbance Rejection Control(ADRC)applied on the tangent linearized system.To apply the ADRC scheme,it is considered the subsystem without the Y-axis component,which is differentially flat and whose flat outputs are obtained using the Kronecker matrix.Numerical assessment using as system parameters the ones of a scale prototype is provided to show the effectiveness of the proposal leading to accurate tracking results using admissible control values for an experimental scenario. 展开更多
关键词 Tilt-rotor ADRC Tangent linearization Multivariable systems Unmanned aerial vehicles
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多准则渔业管理政策优选研究--以东海为例 被引量:4
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作者 江红 程和琴 Francisco Arreguin-Sanchez 《资源科学》 CSSCI CSCD 北大核心 2010年第4期612-619,共8页
本研究在已建立的东海EwE模型基础上,采用EwE中的"渔业政策优选"模块,根据东海渔业资源开发利用现状,模拟系统在经济、社会和生态三重准则下对多种渔业管理政策的响应,并结合层次分析法(AHP)从政策方案中选出"最理想的&q... 本研究在已建立的东海EwE模型基础上,采用EwE中的"渔业政策优选"模块,根据东海渔业资源开发利用现状,模拟系统在经济、社会和生态三重准则下对多种渔业管理政策的响应,并结合层次分析法(AHP)从政策方案中选出"最理想的"东海渔业政策架构。模拟的时间尺度为41年,备选方案包括3个单准则方案、1个多准则方案和31个"复合准则方案"。结果表明:单准则方案和多准则方案将导致各种渔具捕捞努力量发生较大变化。35个方案间的比较分析结果为基于生态系统的东海渔业管理(EBFM)和海洋捕捞作业结构调整提供了一些有益的思路:①单一准则的渔业管理策略和具有相同优先级的多准则渔业管理策略不能实现EBFM总体目标;②就东海目前的渔业经济和社会状况而言,不宜过分地抬高生态系统准则在渔业管理中的地位,经济和社会准则仍然重要;③东海海洋捕捞作业结构调整的总体思路应该是减少拖网和虾拖网作业、控制围网和流刺网作业、大力发展外海渔业。 展开更多
关键词 生态系统 渔业管理 准则 政策优选 EWE AHP 东海
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多层自适应模块化神经网络结构设计 被引量:13
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作者 张昭昭 乔俊飞 余文 《计算机学报》 EI CSCD 北大核心 2017年第12期2827-2838,共12页
针对单一全互连前馈神经网络难以应对复杂问题及模块化神经网络应用时其结构难以确定的问题,该文基于脑式信息处理是采用无监督学习-半监督学习-监督学习的学习机制以及大脑是由多个功能模块组成,每个功能模块中又包含多个子模块,大脑... 针对单一全互连前馈神经网络难以应对复杂问题及模块化神经网络应用时其结构难以确定的问题,该文基于脑式信息处理是采用无监督学习-半监督学习-监督学习的学习机制以及大脑是由多个功能模块组成,每个功能模块中又包含多个子模块,大脑对信息的学习是有目的的选择不同功能模块中多个子模块协同学习的事实,提出一种多层自适应模块化神经网络结构设计方法.其实质是首先对所有的训练数据采用概率密度峰值快速聚类算法确定训练数据的聚类中心,以此确定模块化神经网络中功能模块的个数,其次采用条件模糊聚类实现对每个功能模块中子模块的划分并确定每个子模块的训练样本集;对功能模块中的每一个子模块采用训练误差峰值构造RBF网络的增长算法,该算法能根据分配来的训练样本自适应构建子模块结构;在子模块集成方面,采用基于距离测度的子模块集成方法,该方法能从不同的功能模块中选择不同的子模块对训练样本协同处理.该文提出的模块化神经网络结构设计方法只需要2个人工参数且学习速度提高了近10倍,在一定程度上实现了神经网络的黑箱效应.最后,文中基于人工数据集的复杂函数拟合问题、双螺旋分类问题以及真实数据集的回归问题进行了实验,并与当前国际流行的网络结构进行了对比,结果显示文中提出的模块化神经网络网络结构解决了全互连RBF网络难以应对的复杂问题,而且学习精度高,学习速度快,最终网络的泛化性能强. 展开更多
关键词 模块化神经网络 自适应 径向基函数 脑式信息处理 协同学习
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From flatness, GPI observers, GPI control and flat filters to observer-based ADRC 被引量:8
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作者 Hebertt SIRA-RAMIREZ 《Control Theory and Technology》 EI CSCD 2018年第4期249-260,共12页
In this article, we establish the route taken by the author, and his research group, to bring differential flatness to the realm of active disturbance rejection control (ADRC). This avenue entitled: 1) generalized... In this article, we establish the route taken by the author, and his research group, to bring differential flatness to the realm of active disturbance rejection control (ADRC). This avenue entitled: 1) generalized proportional integral observers (GPIO), as natural state and disturbance observers for fiat systems, 2) generalized proportional integral (GPI) control, provided with extra integrations, to produce a modular controller known as flat filters (FF's) and, finally, 3) the establishing of an equivalence of observer based ADRC with FF's. The context is that of pure integration systems. The obtained controllers depend only on the order of the flat system and they are to be directly used on the basis of the available flat output signal in a universal, modular, fashion. The map is complemented with the relevant references where the intermediate techniques were illustrated and developed, over the years, in connection with laboratory experimental implementations. 展开更多
关键词 FLATNESS GPI observers GPI control reduced order GPI observers fiat filters
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Assessment of gas tungsten arc welding thermal cycles on Inconel 718 alloy 被引量:8
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作者 M.HERNANDEZ R.R.AMBRIZ +3 位作者 R.CORTES C.M.GOMORA G.PLASCENCIA D.JARAMILLO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第3期579-587,共9页
Heat moving source models along with transient heat analysis by finite element method were used to determine weld thermal cycles and isothermal sections obtained from the application of a gas tungsten arc welding bead... Heat moving source models along with transient heat analysis by finite element method were used to determine weld thermal cycles and isothermal sections obtained from the application of a gas tungsten arc welding beads on Inconel 718 plates. Analytical (Rosenthal’s thick plate model) and finite element results show an acceptable approximation with the experimental weld thermal cycles. The isothermal sections determined by numerical simulation show a better approximation with the experimental welding profile for double-ellipse model heat distribution than Gauss model. To analyze the microstructural transformation produced by different cooling rates in the fusion and heat affected zones, Vickers microhardness measurements (profile and mapping representation) were conducted. A hardness decrement for the heat affected zone (~200 HV0.2) and fusion zone (~240 HV0.2) in comparison with base material (~350 HV0.2) was observed. This behavior has been attributed to the heterogeneous solubilization process of the γ″ phase (nickel matrix), which, according to the continuous-cooling-transformation curve, produced the Laves phase,δ and MC transition phases, generating a loss in hardness close to the fusion zone. 展开更多
关键词 Inconel 718 gas tungsten arc welding (GTAW) weld thermal cycle finite element method heat moving source
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road to stemness in hepatocellular carcinoma 被引量:5
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作者 Teresita NJ Flores-Téllez Saúl Villa-Trevino Carolina Pina-Vázquez 《World Journal of Gastroenterology》 SCIE CAS 2017年第37期6750-6776,共27页
Carcinogenic process has been proposed to relay on the capacity to induce local tissue damage and proliferative repair. Liver has a great regeneration capacity and currently, most studies point towards the dominant ro... Carcinogenic process has been proposed to relay on the capacity to induce local tissue damage and proliferative repair. Liver has a great regeneration capacity and currently, most studies point towards the dominant role of hepatocytes in regeneration at all levels of liver damage. The most frequent liver cancer is hepatocellular carcinoma(HCC). Historical findings originally led to the idea that the cell of origin of HCC might be a progenitor cell. However, current linage tracing studies put the progenitor hypothesis of HCC origin into question. In agreement with their dominant role in liver regeneration, mature hepatocytes are emerging as the cell of origin of HCC, although, the specific hepatocyte subpopulation of origin is yet to be determined. The relationship between the cancer cell of origin(CCO) and cancer-propagating cells, known as hepatic cancer stem cell(HCSC) is unknown. It has been challenging to identify the definitive phenotypic marker of HCSC, probably due to the existence of different cancer stem cells(CSC) subpopulations with different functions within HCC. There is a dynamic interconversion among different CSCs, and between CSC and non-CSCs. Because of that, CSC-state is currently defined as a description of a highly adaptable and dynamic intrinsic property of tumor cells, instead of a static subpopulation of a tumor. Altered conditions could trigger the gain of stemness, some of them include: EMT-MET, epigenetics, microenvironment and selective stimulus such as chemotherapy. This CSC heterogeneity and dynamism makes them out reach from therapeutic protocols directed to a single target. A further avenue of research in this line will be to uncover mechanisms that trigger this interconversion of cell populations within tumors and target it. 展开更多
关键词 Cancer stem cell Liver progenitor cell Liver stem progenitor cell STEMNESS PLASTICITY Cancer cell of origin Cancer stem cells subpopulations
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Preparation of neodymium-doped yttrium aluminum garnet powders and fibers 被引量:4
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作者 R. López J. Zárate +1 位作者 E. A. Aguilar J. Muoz-Saldaa 《Journal of Rare Earths》 SCIE EI CAS CSCD 2008年第5期670-673,共4页
Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi- num garnet (YAG) phase was developed. Synthesis of single-phase polycrystalline YAG w... Using nitrate precursors, a novel spray-drying assisted citrate gel process for the preparation of neodymium-doped yttrium alumi- num garnet (YAG) phase was developed. Synthesis of single-phase polycrystalline YAG was achieved at temperatures as low as 800 ℃ using the spray-drying methodology whilst conventional approaches currently available require 1000 ℃. Initially, a solution was prepared by mixing aluminum and yttrium nitrates, citric acid, etilenglycol and neodymium oxide. This solution was dried by pulverization (spray dryer) to obtain aggregated precursor powders of the compound. These aggregates were calcined at 800, 850 and 900 ℃ to determine the phase evolution from amorphous to crystalline by X-ray diffraction (XRD). The morphology of aggregates was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Moreover, through XRD it was determined that the crystallization of YAG phase started at about 800 ℃ without any intermediate phases. The powders were composed of spherical aggregates with an average diameter of 1 um. From these powders, ceramic fibers with additions of 2at.% and 5at.% Nd, were extracted from the melt with diameters ranging from 30 um to 50 um. 展开更多
关键词 SPRAY-DRYING melt extraction fibers yttrium aluminum garnet rare earths
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领导者–跟随者Thomson跳环系统的自抗扰控制设计(英文) 被引量:4
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作者 Mario RAMIREZ-NERIA José L GARCIA-ANTONIO +2 位作者 Hebertt J SIRA-RAMIREZ Martin VELASCO-VILLA Rafael CASTRO-LINARES 《控制理论与应用》 EI CAS CSCD 北大核心 2013年第12期1564-1572,共9页
将用电磁方法悬浮起来的一对环构成领导者–跟随者系统实现对光滑参考轨线的跟踪要求.这一任务通过设计具有对扰动进行在线估计与补偿功能的自抗扰控制器(ADRC)实现.本文设计方法与传统ADRC的主要不同在于领导者和跟随者的跟踪控制器设... 将用电磁方法悬浮起来的一对环构成领导者–跟随者系统实现对光滑参考轨线的跟踪要求.这一任务通过设计具有对扰动进行在线估计与补偿功能的自抗扰控制器(ADRC)实现.本文设计方法与传统ADRC的主要不同在于领导者和跟随者的跟踪控制器设计都是基于平坦输出的线性化近似系统.超出线性化近似有效区域的大的高度偏差所导致的未知非线性则被视为扰动,这个扰动借助于线性扩张观测器进行在线估计并通过线性反馈控制器进行消除.实验结果检验了本文所提方法的有效性. 展开更多
关键词 Thomson跳环 自抗扰控制 广义比例积分(GPI)观测器 领导者-跟随者布局
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一种基于行为空间的回声状态网络参数优化方法 被引量:10
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作者 张昭昭 朱应钦 +1 位作者 乔俊飞 余文 《信息与控制》 CSCD 北大核心 2021年第5期556-565,共10页
针对回声状态网络参数难以选择的问题,提出一种基于行为空间优化回声状态网络参数的方法.其实质是通过泛化等级、核心等级、记忆容量构建回声状态网络行为空间.优化算法采用新颖搜索遗传算法(NSGA),该算法结合K近邻个体距离和NMSE,通过... 针对回声状态网络参数难以选择的问题,提出一种基于行为空间优化回声状态网络参数的方法.其实质是通过泛化等级、核心等级、记忆容量构建回声状态网络行为空间.优化算法采用新颖搜索遗传算法(NSGA),该算法结合K近邻个体距离和NMSE,通过建立行为空间最低配置筛选基因来限定遗传算法的遗传方向,提高优化效率,进而找到影响网络性能的因素.该方法克服了传统回声状态网络(ESN)参数选择困难、遗传算法优化时间长且无合适理论阐明储层性能对任务的影响等缺陷,提升了优化效率和网络学习性能.实验结果表明,本文所提NSGA-ESN方法优化ESN参数基本上接近最佳网络结构,学习性能优于增长回声状态网络,且可以通过行为空间解释影响ESN网络性能的原因. 展开更多
关键词 回声状态网络 泛化等级 核心等级 记忆容量 行为空间
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S-adenosyl-methionine decreases ethanol-induced apoptosis in primary hepatocyte cultures by a c-Jun N-terminal kinase activity-independent mechanism 被引量:2
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作者 Maria del Pilar Cabrales-Romero Lucrecia Márquez-Rosado +4 位作者 Samia FatteI-Fazenda Cristina Trejo-Solis Evelia Arce-Popoca Leticia Alemán-Lazarini Saúl Villa-Trevineo 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第12期1895-1904,共10页
AIM: To determine the role of c-Jun N-terminal kinase (JNK) activity in ethanol-induced apoptosis and the modulation of this signaling cascade by S-Adenosylmethionine (AdoMet). METHODS: Primary hepatocyte cultur... AIM: To determine the role of c-Jun N-terminal kinase (JNK) activity in ethanol-induced apoptosis and the modulation of this signaling cascade by S-Adenosylmethionine (AdoMet). METHODS: Primary hepatocyte cultures were pretreated with 100 IJmol/L SP600125, a selective JNK inhibitor, 1 mL/L DMSO or 4 mmol/L AdoMet and then exposed to 100 mmo/L ethanol. Hepatocyte apoptosis was determined by the TUNEL and DNA ladder assays. JNK activity and its inhibition by SP600125 and AdoMet were determined by Western blot analysis of c-jun phosphorylation and Bid fragmentation. SP600125 and AdoMet effects on the apoptotic signaling pathway were determined by Western blot analysis of cytochrome c release and pro-caspase 3 fragmentation. The AdoMet effect on glutathione levels was measured by EIIman's method and reactive oxygen species (ROS) generation by cell cytometry. RESULTS: The exposure of hepatocytes to ethanol induced JNK activation, c-jun phosphorylation, Bid fragmentation, cytochrome c release and pro-caspase 3 cleavage; these effects were diminished by SP600125, and caused a significant decrease in ethanol-induced apoptosis (P〈 0.05). AdoMet exerted an antioxidant effect maintaining glutathione levels and decreasing ROS generation, without a significant effect on JNK activity, and prevented cytochrome c release and pro-caspase 3 cleavage.CONCLUSION: The JNK signaling cascade is a key component of the proapoptotic signaling pathway induced by ethanol. JNK activation may be independent from ROS generation, since AdoMet which exerted antioxidant properties did not have a significant effect on JNK activity. JNK pathway modulator agents and AdoMet may be components of promising therapies for alcoholic liver disease (ALD) treatment. 展开更多
关键词 Alcoholic liver disease c-Jun N-terminal kinase Apoptosis SP600125 S-Adenosyl methionine BID Reactive oxygen species
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Preparation and Characterization of Flexible, Transparent and Thermally Stable Aromatic Co-polyamides 被引量:3
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作者 José Antonio Tec-Sánchez Andrés Iván Oliva Arias +2 位作者 Manuel Aguilar-Vega Juan Valerio Cauich-Rodríguez José Luis Santiago-García 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2019年第2期136-141,共6页
Two aromatic co-polyamides were synthesized combining two diacid monomers containing bulky pendant groups, 5-(9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)isophthalic acid(DEAIA) and 5-tert-butylisophthalic ... Two aromatic co-polyamides were synthesized combining two diacid monomers containing bulky pendant groups, 5-(9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)isophthalic acid(DEAIA) and 5-tert-butylisophthalic acid(TERT), with 4,4′-(hexafluoroisopropylidene)dianiline(HFA) or 2,3,5,6-tetramethyl-1,4-phenylenediamine(Durene) by direct polycondensation. The structures of the obtained aromatic co-polyamides were confirmed by FTIR, Raman and 1 H-NMR. The co-copolyamide films, DHTH and DDTD, exhibited rms-roughness values between 0.94 and 1.60 nm, respectively. Moreover, they presented good thermal stability up to300 °C. Young's moduli of the co-polyamide films were between 4.1 and 4.3 GPa. X-ray diffraction results showed that the co-polyamide films were amorphous due to the incorporation of both bulky pendant groups, tert-butyl and dibenzobarrelene. The combination of bulky pendant groups provided intrinsically transparent co-polyamide films with a transmittance higher than 88% in the range of 400-780 nm.Due to these outstanding film and optical properties, they are suggested to be flexible substrates in applications for solar cell and other portable electronic devices. 展开更多
关键词 Co-polyamides FLEXIBLE films TRANSMITTANCE Thermal stability POLYCONDENSATION
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Morphometric, Physicochemical, Thermal, and Rheological Properties of Rice (<i>Oryza sativa</i>L.) Cultivars <i>Indica ×Japonica</i> 被引量:2
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作者 Laura Elizabeth Morales-Martínez Luis Arturo Bello-Pérez +2 位作者 Mirna María Sánchez-Rivera Elsa Ventura-Zapata Antonio Ruperto Jiménez-Aparicio 《Food and Nutrition Sciences》 2014年第3期271-279,共9页
The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate... The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate new varieties from Indica and Japonica cultivars. Morphometric parameters of the grains were evaluated by image analysis. Flours were prepared from the whole rice grains and physicochemical, thermal and rheological properties, X-ray diffraction pattern and evaluation of color using the CIELAB system were assessed. The hybrids lines showed long (061, 611, 721), medium (719 and 720) and short (067) grains. The rice samples presented lipids (2.6% - 3.2%), protein (11% - 15%), total dietary fiber (8.4% - 10.2%), total starch (65% - 74%) and apparent amylose (5% - 32%) contents. Gelatinization temperature (Tp) was found in the range of 66.1℃ - 79.4℃ with enthalpy (ΔH) value between 3.4 - 8.1 J/g. The retrogradation parameters (temperature and ΔH) were lower than those for gelatinization in all samples. The rice samples presented A-type X-ray diffraction pattern. Rice pastes showed a non-Newtonian behavior and the brightness (L*) characterize the color of the samples. Hybrid rice grains presented morphometric properties more similar to Japonica than Indica variety. Rice hybrid had higher protein content than Indica variety. Apparent amylose, viscosity and gelatinization temperature varied significantly among hybrids and varieties. 展开更多
关键词 Brown RICE Hybrid Grains MORPHOMETRIC Parameters GELATINIZATION Temperature Flow Behavior PASTING Viscosity
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Active disturbance rejection control of nonlinear SISO Lagrangian systems via endogenous injections and exogenous feedback for trajectory tracking 被引量:2
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作者 Hebertt Sira-Ramírez Mario Andres Aguilar-Orduña Brian C.Góm ez-León 《Control Theory and Technology》 EI CSCD 2021年第1期113-126,共14页
This article deals with a linear classical approach for the robust output reference trajectory tracking control of nonlinear SISO Lagrangian systems with a controllable(fAat)tangent linearization around an operating e... This article deals with a linear classical approach for the robust output reference trajectory tracking control of nonlinear SISO Lagrangian systems with a controllable(fAat)tangent linearization around an operating equilibrium point.An endogenous injections and exogenous feedback(EIEF)approach is proposed,which is naturally equivalent to the generalized propor-tional integral control method and to a robust classical compensation network.It is shown that the EIEF controller is also equivalent,within a frequency domain setting demanding respect for the separation principle,to the reduced order observer based active disturbance rejection control approach.The proposed linear control approach is robust with respect to total dis-turbances and,thus,it is ffective for the linear control of the nonlinear Lagrangian system.An ilustrative nonlinear rotary crane Lagrangian system example,which is non-feedback linearizable,is presented along with digital computer simulations. 展开更多
关键词 Active disturbance rejection control Lagrangian systems Robust control Flatness in Lagrangian systems
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A practical approach to robust impulsive lag synchronization between different chaotic systems 被引量:2
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作者 张化光 马铁东 +1 位作者 Yu Wen 浮洁 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第10期3616-3622,共7页
In this paper, a practical impulsive lag synchronization scheme for different chaotic systems with parametric uncertainties is proposed. By virtue of the new definition of synchronization and the theory of impulsive d... In this paper, a practical impulsive lag synchronization scheme for different chaotic systems with parametric uncertainties is proposed. By virtue of the new definition of synchronization and the theory of impulsive differential equations, some new and less conservative sufficient conditions are established to guarantee that the error dynamics can converge to a predetermined level. The idea and approach developed in this paper can provide a more practical framework for the synchronization between identical and different chaotic systems in parameter perturbation circumstances. Simulation results finally demonstrate the effectiveness of the method. 展开更多
关键词 chaotic systems impulsive control lag synchronization parametric uncertainty
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A unified approach to fuzzy modelling and robust synchronization of different hyperchaotic systems 被引量:4
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作者 张化光 赵琰 +1 位作者 余文 杨东升 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第11期4056-4066,共11页
In this paper, a Takagi Sugeno (T-S) fuzzy model-based method is proposed to deal with the problem of synchronization of two identical or different hyperchaotic systems. The T S fuzzy models with a small number of f... In this paper, a Takagi Sugeno (T-S) fuzzy model-based method is proposed to deal with the problem of synchronization of two identical or different hyperchaotic systems. The T S fuzzy models with a small number of fuzzy IF-THEN rules are employed to represent many typical hyperchaotic systems exactly. The benefit of employing the T-S fuzzy models lies in mathematical simplicity of analysis. Based on the T-S fuzzy hyperchaotic models, two fuzzy controllers arc designed via parallel distributed compensation (PDC) and exact linearization (EL) techniques to synchronize two identical hyperchaotic systems with uncertain parameters and two different hyperchaotic systems, respectively. The sufficient conditions for the robust synchronization of two identical hyperchaotic systems with uncertain parameters and the asymptotic synchronization of two different hyperchaotic systems are derived by applying the Lyapunov stability theory. This method is a universal one of synchronizing two identical or different hyperchaotic systems. Numerical examples are given to demonstrate the validity of the proposed fuzzy model and hyperchaotic synchronization scheme. 展开更多
关键词 hyperchaotic synchronization fuzzy modelling T-S fuzzy model exact linearization (EL)
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Structural studies of BaTiO_3:Er^(3+) and BaTiO_3:Yb^(3+) powders synthesized by hydrothermal method 被引量:3
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作者 Garrido-Hernández A García-Murillo A +4 位作者 Carrillo-Romo F de J Cruz-Santiago L A Chadeyron G Morales-Ramírez A de J Velumani S 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第11期1016-1021,共6页
Erbium and ytterbium doped barium titanate nanopowders were prepared using the hydrothermal method. A barium titanate structure doped with rare earth ions manifested new characteristics and improved the field of appli... Erbium and ytterbium doped barium titanate nanopowders were prepared using the hydrothermal method. A barium titanate structure doped with rare earth ions manifested new characteristics and improved the field of application of optical devices such as trichromatic tubes, LCD displays, lamps, and infrared lasers. In this work, BaTiO3:Er3+ and BaTiO3:Yb3+ were prepared using barium chloride [BaCl2], titanium butoxide [C16H36O4Ti], erbium chloride [ErCl3] and ytterbium chloride [YbCl3] as precursors. Anhydrous methanol was employed as a solvent. Metallic potassium was used to promote solubility in the system and increase the pH to 13. This method yielded the formation of a predominantly cubic structure in both Er3+ and Yb3+ doped BaTiO3 powders. Characteristic bondings of BaTiO3 were observed with FT-IR spectroscopy. The predominantly cubic structure was confirmed by X-ray diffraction and micro-Raman analyses. The particle size(~30 nm) was estimated using the Scherrer equation and X-ray diffraction data. The results were presented and discussed. 展开更多
关键词 NANOPOWDERS HYDROTHERMAL BaTiO3:Er3+ BaTiO3:Yb3+ rare earths
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Relationship between the Environment and Economic Growth in China via Exports: A Perspective of Ecological Impact (2000-2014) 被引量:2
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作者 Guillermo Velázquez Valadez Jiaqi Hu 《Journal of Environmental Protection》 2016年第11期1670-1692,共23页
China’s swift and substantial economic growth over the past 20 years has made the country one of the top industrial powers in the world, second only the United States. From the perspective of ecology and the impact o... China’s swift and substantial economic growth over the past 20 years has made the country one of the top industrial powers in the world, second only the United States. From the perspective of ecology and the impact on the environment produced by economic and industrial growth, the exports that have driven rapid growth have also resulted in an alarming level of environmental pollution in major Chinese cities. Research has shown that the Chinese government’s investment in bringing down pollution levels has been insufficient and ineffective. The monetary amount allocated for pollution reduction has barely reached 0.15% of the country’s GDP and has failed to meaningfully reverse the effects of industrialization, including increased exports and economic growth rates affecting China’s ecology. The present study investigated China’s ecological situation in terms of the industrial production that has generated its level of exports, with special focus on problems related to water, air, and solid waste. An econometric analysis was conducted to determine the relationship between the main variables. The exports and GDP (dependent variable), air pollution, water pollution, and industrial solid waste (independent variables) were provided by the Institute of Statistics and the Environment Institute of China for this study. The data was managed in Econometric Eviews 7.0 software and yielded an adjusted R<sup>2 </sup>of 96.09% (high correlation) with an interesting correlation between the exports and three independent variables;after subsequent variable analysis, we found that investments in water and industrial solid waste were not significant (i.e., that said investments have failed to solve the pollution problem). It is necessary to review the Chinese investment policy with special attention to these variables to appropriately respond to China’s ecological crisis. 展开更多
关键词 Economic Growth Environment EXPORTS POLLUTION Gross Domestic Product
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