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FIRST-PASSAGE FAILURE OF PREISACH HYSTERETIC SYSTEMS

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Acta Mechanica Solida Sinica 2014年第5期27卷 477-485页

作者： Ming xu xiaoling Jin yong Wang Zhilong Huang Institute of Fluid Mechanics China Jiliang University Department of Engineering Mechanics Zhejiang University

The first-passage failure of a single-degree-of-freedom hysteretic system with non- local memory is investigated. The hysteretic behavior is described through a Preisach model with excitation selected as Gaussian white noise. First, the equivalent nonlinear non-hysteretic sys- tem with amplitude-dependent damping and stiffness coefficients is derived through generalized harmonic balance technique. Then, equivalent damping and stiffness coefficients are expressed as functions of system energy by using the relation of amplitude to system energy. The stochastic aver- aging of energy envelope is adopted to accept the averaged It5 stochastic differential equation with respect to system energy. The establishing and solving of the associated backward Kolmogorov equation yields the reliability function and probability density of first-passage time. The effects of system parameters on first-passage failure are investigated concisely and validated through Monte Carlo simulation.

关键词： first-passage failure Preisach hysteretic systems stochastic averaging of energyenvelope generalized harmonic balance technique

Optimal bounded control for maximizing reliability of Duhem hysteretic systems

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Applied Mathematics and Mechanics(English Edition) 2015年第10期36卷 1337-1346页

作者： Ming xu xiaoling JIN yong WANG Zhilong HUANG College of Metrology and Measurement Engineering China Jiliang University Department of Engineering Mechanics Zhejiang University

The optimal bounded control of stochastic-excited systems with Duhem hysteretic components for maximizing system reliability is investigated. The Duhem hysteretic force is transformed to energy-depending damping and stiffness by the energy dissipation balance technique. The controlled system is transformed to the equivalent non- hysteretic system. Stochastic averaging is then implemented to obtain the It5 stochastic equation associated with the total energy of the vibrating system, appropriate for eval- uating system responses. Dynamical programming equations for maximizing system re- liability are formulated by the dynamical programming principle. The optimal bounded control is derived from the maximization condition in the dynamical programming equation. Finally, the conditional reliability function and mean time of first-passage failure of the optimal Duhem systems are numerically solved from the Kolmogorov equations. The proposed procedure is illustrated with a representative example.

关键词： optimal bounded control reliability Duhem hysteretic system stochastic dynamical programming principle

Tacholess order-tracking approach for wind turbine gearbox fault detection

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Frontiers of Mechanical Engineering 2017年第3期12卷 427-439页

作者： Yi WANG yong XIE Guanghua xu Sicong ZHANG chenggang HOU School of Mechanical Engineering Chongqing University Chongqing400044 China School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an 710049 China

Monitoring of wind turbines under variablespeed operating conditions has become an important issue in recent years. The gearbox of a wind turbine is the most important transmission unit; it generally exhibits complex vibration signatures due to random variations in operating conditions. Spectral analysis is one of the main approaches in vibration signal processing. However, spectral analysis is based on a stationary assumption and thus inapplicable to the fault diagnosis of wind turbines under variable-speed operating conditions. This constraint limits the application of spectral analysis to wind turbine diagnosis in industrial applications. Although order-tracking methods have been proposed for wind turbine fault detection in recent years, current methods are only applicable to cases in which the instantaneous shaft phase is available. For wind turbines with limited structural spaces, collecting phase signals with tachometers or encoders is difficult. In this study, a tacholess order-tracking method for wind turbines is proposed to overcome the limitations of traditional techniques. The proposed method extracts the instantaneous phase from the vibration signal, resamples the signal at equiangular increments, and calculates the order spectrum for wind turbine fault identification. The effectiveness of the proposed method is experimentally validated with the vibration signals of wind turbines.

关键词： wind turbine variable-speed operating conditions Vold-Kalman filtering tacholess order tracking

Multi-componential metal intercalated graphite hybrids synthesized by co-intercalation polymerization towards highefficient microwave absorptions

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Nano Research 2023年第5期16卷 6369-6379页

作者： Junhua Su Qinbo Ma Longkun Que Hunan Jiang xiaoling xu yong Wang Yifan Guo Zuowan Zhou Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China School of Chemistry Southwest Jiaotong UniversityChengdu 610031China Yibin Research Institute Southwest Jiaotong UniversityYibin 644000China School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China Research Institute of Frontier Science Southwest Jiaotong UniversityChengdu 610031China

Magnetic expanded graphite(EG)hybrids were synthesized by co-intercalation polymerization of aniline together with transition metal *** results show that metal ions(Fe,Co,Ni,Cu)and even their mixtures can co-intercalate into graphite interlayers with flexibly controllable ratios and *** these co-intercalation compounds,Fe/Ni-intercalated graphite with a predesigned mole ratio of 1:3 transforms into NiFe_(2)O_(4)/FeNi_(3)@EG during the annealing *** synthesized magnetic EG hybrids present multiband microwave absorption in C and X bands due to improved impedance match as well as significantly enhanced interfacial polarization relaxation induced by multi-componential *** reflection values of−39.1 dB at 6.95 GHz and−25.7 dB at 9.4 GHz are achieved with an ultra-low loading of 5 wt.%.This work provides a flexible approach for tuning the components and structures of magnetic EG hybrids,which may contribute to the development of microwave absorption materials with superior performances.

关键词： co-intercalation intercalation polymerization expanded graphite transition metal microwave absorption

Three-dimensional hydrodynamic and water quality model for TMDL development of Lake Fuxian,China

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Journal of Environmental Sciences 2012年第8期24卷 1355-1363页

作者： Lei Zhao xiaoling Zhang yong liu Bin He Xiang Zhu Rui Zou Yuanguan Zhu Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China College of Environmental Science and Engineering Key Laboratory of Water and Sediment Sciences(MOE)Peking UniversityBeijing 100871China Tetra Tech Inc.10306 Eaton PlaceSte 340FairfaxVA 22030USA Institute for Environmental Sciences Kunming 650034China

Lake Fuxian is the largest deep freshwater lake in China. Although its average water quality meets Class I of the China National Water Quality Standard （CNWQS）, i.e., GB3838-2002, monitoring data indicate that the water quality approaches the Class II threshold in some areas. Thus it is urgent to reduce the watershed load through the total maximum daily load （TMDL） program. A three-dimensional hydrodynamic and water quality model was developed for Lake Fuxian, simulating flow circulation and pollutant fate and transport. The model development process consists of several steps, including grid generation, initial and boundary condition configurations, and model calibration processes. The model accurately reproduced the observed water surface elevation, spatiotemporal variations in temperature, and total nitrogen （TN）, total phosphorus （TP）, and chemical oxygen demand （COD） concentrations, suggesting a reasonable numerical representation of the prototype system for further TMDL analyses. The TMDL was calculated using two interpretations of the water quality standards for Class I of the CNWQS based on the maximum instantaneous surface and annual average surface water concentrations. Analysis of the first scenario indicated that the TN, TP and COD loads should be reduced by 66%, 68% and 57%, respectively. Water quality was the highest priority; however, local economic development and cost feasibility for load reduction can pose significant issues. In the second interpretation, the model results showed that, under the existing conditions, the average water quality meets the Class I standard and therefore load reduction is unnecessary. Future studies are needed to conduct risk and cost assessments for realistic decision-making.

关键词： hydrodynamic and water quality model Lake Fuxian water quality prediction total maximum daily load

Green rusts-derived iron oxide nanostructures catalyze NO reduction by CO

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Green Energy & Environment 2023年第2期8卷 499-508页

作者： Ping Wang xiaoling Mou yong Li Wenjie Shen Hangzhou Institute of Advanced Studies Zhejiang Normal UniversityHangzhou311231China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China

Green rusts with brucite-like layers of hydroxide intercalated with anions constitute a family of diverse precursors for the synthesis of iron oxides via dehydration,but precise structural control of the resulting oxides with respect to the size and shape at the nanometer level remains challenging due to the easy oxidation of the ferrous ***,we report a new synthetic strategy for the facile preparation of fibrous-like green rusts by using appropriate balancing anions(CO_(3)^(2-)and SO_(4)^(2-))in ethylene glycol to regulate the *** on the type of the intercalating anion,the green rusts were converted into hematite with fibrous-or plate-like shapes upon thermal *** evaluated in the reaction of NO reduction by CO,these iron oxides showed a prominent shape-dependent catalytic *** fibrous-like Fe_(2)O_(3)was much more catalytically active and structurally robust than the plate-like *** spectroscopic and microscopic characterizations on the nanostructured iron oxides revealed that the superior performance of the fibrous-like Fe_(2)O_(3)stemmed from a facile Fe_(2)O_(3)/Fe_(3)O_(4)redox cycle and a higher density of active sites for NO activation.

关键词： Green rust Hematite Morphology NO reduction by CO Redox cycle

Secure Data Transfer and Deletion from Counting Bloom Filter in Cloud Computing

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Chinese Journal of Electronics 2020年第2期29卷 273-280页

作者： YANG Changsong TAO xiaoling ZHAO Feng WANG yong School of Cyber Engineering Xidian University School of Computer Science and Information Security Guilin University of Electronic Technology

With the rapid development of cloud storage, an increasing number of data owners prefer to outsource their data to the cloud server, which can greatly reduce the local storage overhead. Because different cloud service providers offer distinct quality of data storage service, e.g., security, reliability, access speed and prices,cloud data transfer has become a fundamental requirement of the data owner to change the cloud service ***, how to securely migrate the data from one cloud to another and permanently delete the transferred data from the original cloud becomes a primary concern of data owners. To solve this problem, we construct a new counting Bloom filter-based scheme in this paper. The proposed scheme not only can achieve secure data transfer but also can realize permanent data deletion. Additionally,the proposed scheme can satisfy the public verifiability without requiring any trusted third party. Finally, we also develop a simulation implementation that demonstrates the practicality and efficiency of our proposal.

关键词： Cloud storage Data deletion Data transfer Counting Bloom filter Public verifiability

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基于时间粒度的网络流量分析模型研究

微计算机信息 2005年第6X期21卷 4-6页

作者：谭晓玲许勇梅成刚刘兰重庆三峡学院电子工程系重庆市万州区404000 广州华南理工大学广东省计算机网络重点实验室 510640

针对不同时间粒度的流量特性,建立不同的流量模型进行分析研究,对网络规划设计、保证服务质量以及网管等都能提供必不可少的依据。本文通过对不同时间粒度的实际流量建模,利用相应的数学工具进行模拟预测,实验结果表明,预测得到的流量... 详细信息

针对不同时间粒度的流量特性,建立不同的流量模型进行分析研究,对网络规划设计、保证服务质量以及网管等都能提供必不可少的依据。本文通过对不同时间粒度的实际流量建模,利用相应的数学工具进行模拟预测,实验结果表明,预测得到的流量数据较好反映了真实流量的分布情况。

关键词：网络流量时间粒度流量模型

Seru Scheduling Problems with Multiple Due-Windows Assignment and Learning Effect

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Journal of Systems Science and Systems Engineering 2022年第4期31卷 480-511页

作者： Yujing Jiang Zhe Zhang xiaoling Song yong Yin School of Economics and Management Nanjing University of Science and TechnologyNanjing210094P.R.China Graduate School of Business Doshisha UniversityKarasuma-ImadegawaKamigyo-kuKyoto602-8580Japan

This paper deals with seru scheduling problems with multiple due windows assignment and DeJong’s learning *** time intervals are assigned to jobs with multiple due windows and learning effect is introduced to characterize the decrease of processing times with the accumulation of the working *** assume that the set of jobs assigned to each due window is independent,and no inclusion exists between due *** objective is to determine the optimal due window positions and sizes,the set of jobs assigned to each due window,and the optimal schedule in each seru to minimize a multidimensional function,which consists of the earliness and tardiness punishment cost,as well as the due window related starting time and size *** find that when the number of jobs and the due windows assigned to each seru are pre-specified in advance,the problem can be solved in polynomial ***,the impacts of the due-window allocation strategy and learning effect on the total cost are respectively discussed based on numerical examples and special *** results show that if each seru is assigned with the same number of due windows,the total cost can be reduced with the increasing ratio of the due-window number to the to-be-processed job ***,with an increasing learning effect,the total cost will be decreased.

关键词： Scheduling seru production system due windows learning effect