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Journal of Electronic Science and Technology 2020年第2期18卷 190-200页

作者： Ali Alouache qing-He wu School of Automation Beijing Institute of TechnologyBeijing 100081

This paper discusses consensus tracking of single-integrator multi-agent systems with a time varying reference state based on the least squares estimation theory to deal with the case of communications *** none of the followers can communicate with the leader within the accepted time due to communications disturbance, least squares estimation is applied for online estimation of the time varying reference state and reducing the tracking errors occurred due to communications disturbance. A theoretical proof is provided under some assumptions while the necessary and sufficient conditions are demonstrated for which consensus is reached on the time-varying reference state in case of communications disturbance. Finally, a Matlab example is given to validate the effectiveness of the proposed approach.

关键词： agent estimation online

Genesis of the Nuri Cu-W-Mo Deposit,Tibet,China:Constraints from in situ Trace Elements and Sr Isotopic Analysis of Scheelite

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 117-131页

作者： WANG Yiyun wu Zhishan CHEN Wenqing du qing’an TANG Liwei SHI Hongzhao MA Guotao ZHANG Zhi LIANG Wei wu Bo MIAO Hengyi Chengdu Center China Geological Survey(Geoscience Innovation Center of Southwest China)Chengdu 610081China The Second Geological Institute of China’s Metallurgical Geology Bureau Fuzhou 351111China

The Nuri deposit is the only Cu-W-Mo polymetallic deposit with large-scale WO3 resources in the eastern section of the Gangdese metallogenic belt,Tibet,***,the genetic type of this deposit has been controversial since its *** on a study of the geological characteristics of the deposit,this study presents mineralization stages,focusing on the oxide stage and the quartz-sulfide stage where scheelite is mainly formed,referred to as Sch-A and Sch-B,*** LA-ICP-MS trace element and Sr isotope analyses,the origin,evolutionary process of the oreforming fluid and genesis of the ore deposit are *** Electron Microscope-Cathodoluminescence(SEMCL)observations reveal that Sch-A consists of three generations,with dark gray homogenous Sch-A1 being replaced by relatively lighter and homogeneous Sch-A2 and Sch-A3,with Sch-A2 displaying a gray CL image color with vague and uneven growth bands and Sch-A3 has a light gray CL image color with hardly any growth *** contrast,Sch-B exhibits a‘core-rim’structure,with the core part(Sch-B1)being dark gray and displaying a uniform growth band,while the rim part(Sch-B2)is light gray and *** normalized distribution pattern of rare earth elements in scheelite and Sr isotope data suggest that the early ore-forming fluid in the Nuri deposit originated from granodiorite porphyry and,later on,some country rock material was mixed in,due to strong water-rock *** the O-H isotope data further indicates that the ore-forming fluid in the Nuri deposit originated from magmatic-hydrothermal sources,with contributions from metamorphic water caused by water-rock interaction during the mineralization process,as well as later meteoric *** intense water-rock interaction likely played a crucial role in the precipitation of scheelite,leading to varying Eu anomalies in different generations of scheelite from the oxide stage to the quartz-sulfide stage,while also causing a

关键词： trace elements in situ Sr isotopes tungsten mineralization Gangdese metallogenic belt Tibet

New family of piecewise smooth support vector machine

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Journal of Systems Engineering and Electronics 2015年第3期26卷 618-625页

作者： qing wu Leyou Zhang Wan Wang School of Automation Xi'an University of Posts and Telecommunications School of Mathematics and Statistics Xidian University School of Computer Science and Technology Xi'an University of Posts and Telecommunications

Support vector machines （SVMs） have been extensively studied and have shown remarkable success in many applications. A new family of twice continuously differentiable piecewise smooth functions are used to smooth the objective function of uncon- strained SVMs. The three-order piecewise smooth support vector machine （TPWSSVMd） is proposed. The piecewise functions can get higher and higher approximation accuracy as required with the increase of parameter d. The global convergence proof of TPWSSVMd is given with the rough set theory. TPWSSVMd can efficiently handle large scale and high dimensional problems. Nu- merical results demonstrate TPWSSVMa has better classification performance and learning efficiency than other competitive base- lines.

关键词： support vector machine (SVM) piecewise smooth function smooth technique bound of convergence.

Adjustable entropy function method for support vector machine

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Journal of Systems Engineering and Electronics 2008年第5期19卷 1029-1034页

作者： wu qing Liu Sanyang Zhang Leyou Dept. of Mathematical Sciences Xidian Univ. Xi'an 710071 P. R. China

Based on KKT complementary condition in optimization theory, an unconstrained non-differential optimization model for support vector machine is proposed. An adjustable entropy function method is given to deal with the proposed optimization problem and the Newton algorithm is used to figure out the optimal solution. The proposed method can find an optimal solution with a relatively small parameter p, which avoids the numerical overflow in the traditional entropy function methods. It is a new approach to solve support vector machine. The theoretical analysis and experimental results illustrate the feasibility and efficiency of the proposed algorithm.

关键词： optimization support vector machine adjustable entropy function Newton algorithm.

On Optimal Mean-Field Control Problem of Mean-Field Forward-Backward Stochastic System with Jumps Under Partial Information

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Journal of Systems Science & Complexity 2017年第4期30卷 828-856页

作者： ZHOU qing REN Yong wu Weixing School of Science Beijing University of Posts and Telecommunications Department of Mathematics Anhui Normal University Research Center of Applied Finance and School of Finance and Banking University of International Business and Economics

This paper considers the problem of partially observed optimal control for forward-backward stochastic systems driven by Brownian motions and an independent Poisson random measure with a feature that the cost functional is of mean-field type. When the coefficients of the system and the objective performance functionals are allowed to be random, possibly non-Markovian, Malliavin calculus is employed to derive a maximum principle for the optimal control of such a system where the adjoint process is explicitly expressed. The authors also investigate the mean-field type optimal control problem for the system driven by mean-field type forward-backward stochastic differential equations(FBSDEs in short) with jumps, where the coefficients contain not only the state process but also its expectation under partially observed information. The maximum principle is established using convex variational technique. An example is given to illustrate the obtained results.

关键词： Forward-backward stochastic differential equation Girsanov's theorem jump diffusion Malliavin calculus maximum principle mean-field type partial information.

Vector quantization: a review

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Frontiers of Information Technology & Electronic Engineering 2019年第4期20卷 507-524页

作者： Ze-bin wu Jun-qing YU Department of Computer Science and Technology Huazhong University of Science and Technology Center of Network and Computation Huazhong University of Science and Technology

Vector quantization(VQ) is a very effective way to save bandwidth and storage for speech coding and image coding. Traditional vector quantization methods can be divided into mainly seven types, tree-structured VQ,direct sum VQ, Cartesian product VQ, lattice VQ, classified VQ, feedback VQ, and fuzzy VQ, according to their codebook generation procedures. Over the past decade, quantization-based approximate nearest neighbor(ANN)search has been developing very fast and many methods have emerged for searching images with binary codes in the memory for large-scale datasets. Their most impressive characteristics are the use of multiple codebooks. This leads to the appearance of two kinds of codebook: the linear combination codebook and the joint codebook. This may be a trend for the future. However, these methods are just finding a balance among speed, accuracy, and memory consumption for ANN search, and sometimes one of these three suffers. So, finding a vector quantization method that can strike a balance between speed and accuracy and consume moderately sized memory, is still a problem requiring study.

关键词： Approximate nearest neighbor search Image coding Vector quantization

Biodegradation and detoxification of the triphenylmethane dye coomassie brilliant blue by the extracellular enzymes from mycelia of Lactarius deliciosus

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Frontiers of Chemical Science and Engineering 2021年第2期15卷 421-436页

作者： Jin Zhao qing-Xi wu Xiao-du Cheng Ting Su Xiao-Hui Wang Wen-Na Zhang Yong-Ming Lu Yan Chen School of Life Sciences Anhui UniversityHefei 230601China Anhui Key Laboratory of Modern Biomanufacturing Hefei 230601China

Fungi play an important role in dying wastewater *** this work,the mycelia of Lactarius deliciosus exhibited an excellent capacity in decolorizing coomassie brilliant blue(CBB).The results demonstrated that the mycelia could treat CBB with high concentrations over a broad range of pH and *** decolorization rate of 99.19%and the removal rate of 16.31 mg·L^(‒1)·h were *** mycelia could be recycled from decolorizing process for 19 times,indicating a good *** verified that the lignin peroxidase(121.65 U·L^(‒1))and manganese peroxidase(36.77 U·L^(‒1))were involved in the degradation and decolorization process of *** assessments indicated the seed germination rate was up to 82.22%while inhibition to Escherichia coli decreased dramatically and no significant effect on Caenorhabditis elegans growth was *** removal of CBB was a synergistic process accomplished by adsorption and *** mycelia could be used for eco-friendly CBB treatment.

关键词： fungus mycelia biodegradation extracellular enzymes coomassie brilliant blue Lactarius deliciosus

Pricing of Defaultable Securities Associated with Recovery Rate Under the Stochastic Interest Rate Driven by Fractional Brownian Motion

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Journal of Systems Science & Complexity 2019年第2期32卷 657-680页

作者： ZHOU qing WANG Qian wu Weixing School of Science Beijing University of Posts and Telecommunications School of Banking and Finance University of International Business and Economics

This paper considers an improved model of pricing defaultable bonds under the assumption that the interest rate satisfies the Vasicek model driven by fractional Brownian motion(fBm for short)based on the counterparty risk framework of Jarrow and Yu(2001). The authors use the theory of stochastic analysis of f Bm to derive pricing formulas for the defaultable bonds and study how the counterparty risk, recovery rate, and the Hurst parameter affect the values of the defaultable *** experiment results are presented to demonstrate the findings.

关键词： Counterparty risk defaultable bond fractional Brownian motion recovery rate Vasicek model

Microstructure and surface of 2A12 aluminum alloy cladded with pure aluminum after solution treatment

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Rare Metals 2021年第10期40卷 2937-2946页

作者： Sen du Yong-An Zhang Li-Zhen Yan Xi-wu Li Zhi-Hui Li Bai-qing Xiong Hong-Wei Yan Kai Wen GRIMAT Engineering Institute Co. LtD.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China State Key Laboratory of Nonferrous Metals and Processes GRINM Group Co.LtD.Beijing 100088China

The effects of solution temperature and holding time on the microstructure, mechanical properties and surface morphology of 2 A12 aluminum alloy sheets were discussed in this paper. The universal tensile tester was used to test the tensile strength and yield strength of aluminum alloy sheets with different treatment systems. The surface morphology of the alloy sheets was characterized by a white light interference profile scanner, and the microstructure of the sheets was characterized by optical microscope(OM), scanning electron microscope(SEM)and electron backscattered diffraction(EBSD). The results showed that the mechanical properties of the sheets could not satisfy GBT228.1-2010 national standard when the holding time was 10 min and the holding temperature was475 ℃. However, under the other heat treatment systems,the alloy could reach the GBT228.1-2010 national standard. Moreover, with the extension of the holding time, the part of the matrix gradually diffused into the aluminumclad layer. When the holding time was shorter than 25 min,the boundary between the matrix and the aluminum-clad layer was relatively obvious. And the diffusion gradually became obvious when the holding time was over 25 ***, the boundary became blurry. The further investigation suggested that the solution temperature of495 ℃ and the holding time of 35 min showed better mechanical properties and better surface morphology.

关键词： 2A12 aluminum alloy Surface topography Aluminum layer Solution treatment

Aerodynamic shape optimization for alleviating dynamic stall characteristics of helicopter rotor airfoil

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Chinese Journal of Aeronautics 2015年第2期28卷 346-356页

作者： Wang qing Zhao Qijun wu Qi National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics Nanjing University of Aeronautics and Astronautics

In order to alleviate the dynamic stall effects in helicopter rotor, the sequential quadratic programming （SQP） method is employed to optimize the characteristics of airfoil under dynamic stall conditions based on the SC1095 airfoil. The geometry of airfoil is parameterized by the class-shape-transformation （CST） method, and the C-topology body-fitted mesh is then automati- cally generated around the airfoil by solving the Poisson equations. Based on the grid generation technology, the unsteady Reynolds-averaged Navier-Stokes （RANS） equations are chosen as the governing equations for predicting airfoil flow field and the highly-efficient implicit scheme of lower-upper symmetric Gauss-Seidel （LU-SGS） is adopted for temporal discretization. To capture the dynamic stall phenomenon of the rotor more accurately, the Spalart-Allmaras turbulence model is employed to close the RANS equations. The optimized airfoil with a larger leading edge radius and camber is obtained. The leading edge vortex and trailing edge separation of the opti- mized airfoil under unsteady conditions are obviously weakened, and the dynamic stall character- istics of optimized airfoil at different Mach numbers, reduced frequencies and angles of attack are also obviously improved compared with the baseline SC1095 airfoil. It is demonstrated that the optimized method is effective and the optimized airfoil is suitable as the helicopter rotor airfoil.

关键词： Airfoil Computational fluiddynamics Dynamic stall Helicopter Optimization Rotor