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Restoring force correction based on online discrete tangent stiffness estimation method for real-time hybrid simulation

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Earthquake Engineering and Engineering Vibration 2018年第4期17卷 805-820页

作者： huang Liang Guo Tong Chen Cheng Chen Menghui School of Civil Engineering Southeast University Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Southeast University School of Engineering San Francisco State University

In real-time hybrid simulation（RTHS）, it is difficult if not impossible to completely erase the error in restoring force due to actuator response delay using existing displacement-based compensation methods. This paper proposes a new force correction method based on online discrete tangent stiffness estimation（online DTSE） to provide accurate online estimation of the instantaneous stiffness of the physical substructure. Following the discrete curve parameter recognition theory, the online DTSE method estimates the instantaneous stiffness mainly through adaptively building a fuzzy segment with the latest measurements, constructing several strict bounding lines of the segment and calculating the slope of the strict bounding lines, which significantly improves the calculation efficiency and accuracy for the instantaneous stiffness estimation. The results of both computational simulation and real-time hybrid simulation show that：（1） the online DTSE method has high calculation efficiency, of which the relatively short computation time will not interrupt RTHS; and（2） the online DTSE method provides better estimation for the instantaneous stiffness, compared with other existing estimation methods. Due to the quick and accurate estimation of instantaneous stiffness, the online DTSE method therefore provides a promising technique to correct restoring forces in RTHS.

关键词： online discrete tangent stiffness estimation restoring force correction fuzzy segment parameter updating real-time hybrid simulation

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Shanghai center project excavation induced ground surface movements and deformations

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Frontiers of Structural and Civil Engineering 2018年第1期12卷 26-43页

作者： Guolin XU Jiwen ZHANG huang LIU Changqin REN Department of Civil Engineering Southwest Forestry University Kunming 650224 China Department of Civil Engineering University of Kentucky Lexington KY 40506-0281 USA Shanghai Geotechnical Investigations & Design Institute Company Limited Shanghai 200032 China

Empirical data on deep urban excavations can provide designers a significant reference basis for assessing potential deformations of the deep excavations and their impact on adjacent structures. The construction of the Shanghai Center involved excavations in excess of 33-m-deep using the top-down method at a site underlain by thick deposits of marine soft clay. A retaining system was achieved by 50-m-deep diaphragm walls with six levels of struts. During construction, a comprehensive instrumentation program lasting 14 months was conducted to monitor the behaviors of this deep circular excavation. The following main items related to ground surface movements and deformations were collected：（1） walls and circumferential soils lateral movements; （2） peripheral soil deflection in layers and ground settlements; and （3） pit basal heave. The results from the field instrumentation showed that deflections of the site were strictly controlled and had no large movements that might lead to damage to the stability of the foundation pit. The field performance of another 21 cylindrical excavations in top-down method were collected to compare with this case through statistical analysis. In addition, numerical analyses were conducted to compare with the observed data. The extensively monitored data are characterized and analyzed in this paper.

关键词： deep excavation foundation pit soft clay top-down method field observation ground surface movements,ground deformations

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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

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Effects of bacteria on nitrogen and phosphorus release from river sediment

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Journal of Environmental Sciences 2008年第4期20卷 404-412页

作者： WU Qunhe ZHANG Renduo huang Shan ZHANG Hengjun School of Environmental Science and Engineering Sun Yat-Sen （Zhongshan） University Guangzhou 510275 China

To better understand the mechanisms of eutrophication, we addressed the microbial processes that influence many key aspects of water-sediment systems. In this study, a large column experiment was conducted for 30 d. Along the column, solution samples were collected at different locations at different time. The samples were analyzed for physical, chemical, and biological properties of the sediment and overlying water. The results showed that the amount of nitrogen transforming bacteria was higher than that of phosphorous bacteria. The amount of nitrogen transforming bacteria was in the order： ammonifier 〉 denitrifying bacteria 〉 nitrobacteria and nitrosomonas. Principal component analysis indicated that the three main factors accounted for more than 90% overall contributions for bacterium growth, which represented nutrition, organics and oxygen, and pH and redox potential （Eh） of the environment. Corresponding to the bacteria, the concentrations of nitrogen in the system was in the order： ammonia （NH4＋-N）〉 nitrate （NO3^--N）〉 nitrite （NO2^--N）. The fluxes of N and P clearly showed a temporal release and adsorption processes in the water-sediment system. The large magnitude of N fluxes suggested that N might act as an important contamination source for the water quality. However, P exchange between the sediment and overlying water was less intensive during the experiment.

关键词： eutrophication sediment P and N transforming bacteria

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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

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Semi-supervised Artificial Immune Mixture Models Clustering

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Chinese Journal of Electronics 2016年第2期25卷 249-255页

作者： huang Wenlong WANG Xiaodan LI Guohong KANG Hongxia Air and Missile Defense College Air Force Engineering University State Key Laboratory of Astronautic Dynamics Xi'an Satellite Control Center

Learning with partly labeled data aims at combining labeled and unlabeled data in order to boost the accuracy of an algorithm. The traditional Expectation maximization(EM) algorithm only produces locally optimal solutions, it is sensitive to initialization, and the number of components of mixture model must be known in advance. We propose a novel semi-supervised clustering algorithm that uses Gaussian mixture models(GMM) as the underlying clustering model. A novel adaptive global search mechanism is introduced into semi-supervised gaussian mixture model-based clustering, where the EM algorithm is incorporated with the ideas of an immune clonal selection technique. The new algorithm overcomes the various problems associated with the traditional EM algorithm. And it can improve the effectiveness in estimating the parameters and determining the optimal number of clusters automatically. The experimental results illustrate the proposed algorithm provides significantly better clustering results, when compared with other methods of incorporating equivalence constraints.

关键词： Semi-supervised clustering Mixture model Immune clonal selection Globally optimal solution

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Visible light promoted synthesis of N-aroylsulfoximines by oxidative C–H acylation of NH-sulfoximines

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Science China Chemistry 2019年第9期62卷 1213-1220页

作者： Wenlong Jiang Youming huang Lihong Zhou Qingle Zeng State Key Laboratory of Geohazard Prevention and Geoenvironment Protection College of Materials Chemistry & Chemical Engineering Chengdu University of Technology Chengdu 610059 China College of Environment and Ecology Chengdu University of Technology Chengdu 610059 China

The visible light-promoted synthesis of N-aroylsulfoximines has been accomplished via an oxidative dehydrogenative coupling at room temperature under air without the addition of a photosensitizer, metal catalyst, or base. This process exhibits good functional group tolerance, allows facile isolation and purification, and affords N-aroylsulfoximines with high efficiency. The efficiency of the newly developed protocol is described in detail with 27 examples with yields ranging from 80% to 96%.Furthermore, the chirality of the NH-sulfoximine is completely maintained in the desired N-aroylsulfoximine product(>99% ee).

关键词： visible light aldehyde sulfoximines acylation oxidative dehydrogenative coupling

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THE EFFECTS OF COD BONE GELATIN ON TRABECULAR MICROSTRUCTURE AND MECHANICAL PROPERTIES OF CANCELLOUS BONE

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Acta Mechanica Solida Sinica 2015年第1期28卷 1-10页

作者： Renhan huang Qiguo Rong Xiaolong Han Yong Li College of Engineering Peking Universiry China Astronaut Research and Training Center Department of Space Food and Nutrition School of Public Health Peking University

Osteoporosis is a common clinical complication of post-menopausal women and the elderly and can significantly complicate the severity of bone fragility. The purpose of this study is to investigate how cod bone gelatin administration influences trabecular biomechanical properties after ovariectomy. Both biomechanical properties and trabecular microarchitectures were evaluated for cancellous bone samples from female ovariectomized rats, which were either shamoperated or treated with marine peptide （0.75, 1.5, 3.0, 6.0 g/kg body weight） for 90 days. The results have confirmed that cod bone gelatin treatment is effective in the prevention of mechanical property loss by preserving bone mass and trabecular architecture.

关键词： osteoporosis cod bone gelatin trabecular microarchitecture finite element analysis

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An intelligent control method for a large multi-parameter environmental simulation cabin

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Chinese Journal of Aeronautics 2013年第6期26卷 1360-1369页

作者： Li Ke Liu Wangkai Wang Jun huang Yong Fundamental Science on Ergonomics and Environment Control Laboratory School of Aeronautic Science and Engineering Beihang University

The structure and characteristics of a large multi-parameter environmental simulation cabin are *** to the diffculties of control methods and the easily damaged characteristics,control systems for the large multi-parameter environmental simulation cabin are diffcult to be controlled quickly and accurately with a classical PID *** the dynamic state characteristics of the environmental simulation test chamber,a lumped parameter model of the control system is established to accurately control the multiple parameters of the environmental chamber and a fuzzy control algorithm combined with expert-PID decision is introduced into the temperature,pressure,and rotation speed control *** simulations and experimental results have shown that compared with classical PID control,this fuzzy-expert control method can decrease overshoot as well as enhance the capacity of anti-dynamic disturbance with *** can also resolve the contradiction between rapidity and small overshoot,and is suitable for application in a large multi-parameter environmental simulation cabin control system.

关键词： Environmental cabin Environmental testing Expert system Fuzzy control Mathematical models Turbines

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Lipid Is Moving to the Forefront of Bio-Medical Research

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Journal of Genetics and Genomics 2014年第5期41卷 229-230页

作者： Guanghou Shui Xun huang State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of Sciences

While conventionally perceived as major components of cellular membranes and lipid droplets （LDs）, lipids have now emerged as key players with distinctive roles involving in a wide range of biological processes such as signaling events, trafficking, and compartmentalization of macromolecules. One of the key concerns in lipid research is its homeostasis, which is fundamental to health maintenance of cells, living organisms and human beings. It is evident now that deregulated lipid metabolism plays very important roles in many human diseases such as type 2 diabetes, cardiovascular diseases, Alzheimer＇s disease （AD）, Parkinson＇s disease, cancer and infectious diseases （Lam and Shui, 2013）.

关键词： In Lipid Is Moving to the Forefront of Bio-Medical Research

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