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Science China(Technological Sciences) 2015年第1期58卷 147-157页

作者： zhang qing HUA RuHao YE ZhengYin School of Aeronautics Northwestern Polytechnical University

Our research aim is to investigate the buffet alleviation effect of static or vibrating bulges attached on the forebody surface of the *** and numerical simulations on a model consisting of a sharp-edged,70°-leading edge sweep delta wing and twin swept back vertical tails were *** with different bulges were tested and computed at 10 and 20 m/s of free stream velocity at angles of attack ranging from 20°–50°.Dynamic strain gauge and multichannel data acquisition and analysis system were employed for the measurement of unsteady root strain on the vertical *** and computational results show that both static and vibrating bulges behave effectively as a novel tool to alleviate tail buffet,and the alleviation effect depends largely on the vibrating ***,one-sided bulge can only alleviate the buffeting response for the tail of the same side,and it has no obvious alleviation effect for the opposite *** of the spectral analysis reveal that there are generally three peaks of spectral density for aircrafts of this configuration,and bulges used in this paper could alleviate tail buffeting,but the total lift and drag of the whole model show no obvious deviation compared to the base model and the dominant frequency of the vibration of the tails has not shifted.

关键词： forebody bulge delta wing/twin tail configuration vortex breakdown self-induction theory buffet suppression

Development of two-dimensional numerical wave tank based on lattice Boltzmann method

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Journal of Hydrodynamics 2020年第1期32卷 116-125页

作者： Guang-wei Liu qing-he zhang Jin-feng zhang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

A 2-D numerical wave tank(NWT)is developed using the lattice Boltzmann method(LBM)and a multi-relaxation-time(MRT)collision model coupled with an algebraic volume of fluid(VOF)scheme for free surface *** external force based on the momentum source function is used to generate the waves,and a zone of porous media is used to absorb the *** simulations of the progressive and standing waves show that the NWT can generate stable wave trains in agreement with the analytical solutions and eliminate the re-reflection *** NWT is used to simulate two problems encountered in practice,namely:the wave transformation over a submerged breakwater and the wave runup on a sea *** numerical predictions are in good agreement with the measured data.

关键词： Numerical wave tank(NWT) wave generation method volume of fluid(VOF) lattice Boltzmann method(LBM)

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.

Optimal Design for a Retrial Queueing System with State-Dependent Service Rate

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Journal of Systems Science & Complexity 2017年第4期30卷 883-900页

作者： zhang Xuelu WANG Jinting MA qing Department of Mathematics Beijing Jiaotong University School of Science Qilu University of Technology Department of Basic Courses Shandong Women’s University

This paper considers a single server retrial queue in which a state-dependent service policy is adopted to control the service rate. Customers arrive in the system according to a Poisson process and the service times and inter-retrial times are all exponentially distributed. If the number of customers in orbit is equal to or less than a certain threshold, the service rate is set in a low value and it also can be switched to a high value once this number exceeds the threshold. The stationary distribution and two performance measures are obtained through the partial generating functions. It is shown that this state-dependent service policy degenerates into a classic retrial queueing system without control policy under some conditions. In order to achieve the social optimal strategies, a new reward-cost function is established and the global numerical solutions, obtained by Canonical Particle Swarm Optimization algorithm, demonstrate that the managers can get more benefits if applying this state-dependent service policy compared with the classic model.

关键词： Particle swarm optimization algorithm retrial queues social optimal strategy statedependent service policy

BAHA:A Novel Approach to Automatic Bug Report Assignment with Topic Modeling and Heterogeneous Network Analysis

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Chinese Journal of Electronics 2016年第6期25卷 1011-1018页

作者： zhang Wen WANG Song WANG qing School of Economics and Management Beijing University of Chemical Technology Department of Electrical and Computer Engineering at University of Waterloo Laboratory of Internet Technologies Institute of SoftwareChinese Academy of Sciences

We propose an approach called Bug report assignment with topic modeling and heterogeneous network analysis(BAHA) to automatically assign bug reports to developers. Existing studies adopt social network analysis to characterize the collaboration of developers. The networks used in these studies are all homogenous. In real practice of bug resolution, different developers collaborate on different bug reports that makes the homogenous network unable to capture this information. We use heterogeneous network to describe the relations between reporters,bug reports and developers to characterize developers’ collaboration. Experiments on Eclipse JDT pro ject show that BAHA outperforms the state of art methods on automatic bug report assignment.

关键词： Bug report assignment Topic model Heterogeneous network Bug report tracking

Optimization of structural parameters for spatial flexible redundant manipulators with maximum ratio of load to mass

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光学精密工程 2005年第5期13卷 561-569页

作者： zhang Xu-ping YU Yue-qing Department of Mackine Design School of Mechanical Engineering Beijing Polytechnic University Beijing 100022 China

Optimization of structural parameters aimed at improving the load carrying capacity of spatial flexible redundant manipulators is presented in this paper. In order to increase the ratio of load to mass of robots, the cross-sectional parameters and constructional parameters are optimized respectively. The cross-sectional and configurational parameters are optimized simultaneously. The numerical simulation of a 4R spatial manipulator is performed. The results show that the load capacity of robots has been greatly improved through the optimization strategies proposed in this paper.

关键词：调节器结构参数机器人动力性质 KED

Syngas production by photoreforming of formic acid with 2D V_(x)W_(1-x)N_(1.5) solid solution as an efficient cocatalyst

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Frontiers in Energy 2024年第5期18卷 640-649页

作者： Xiaoyuan Ye Yuchen Dong Ziying zhang Wengao Zeng Bin Zhu tuo zhang Ze Gao Anna Dai Xiangjiu Guan International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

Formic acid(FA)is a potential biomass resource of syngas with contents of carbon monoxide(CO,60 wt.%)and hydrogen(H_(2),4.4 wt.%).Among the technologies for FA conversion,the photoreforming of FA has received widespread attention due to its use of green solar energy conversion technology and mild reaction ***,a V-W bimetallic solid solution,V_(x)W_(1-x)N_(1.5) with efficient co-catalytic properties was first and facilely *** CdS was used as a photocatalyst,the activity performance of the V_(0.1)W_(0.9)N_(1.5) system was over 60%higher than that of the W_(2)N_(3) *** computational simulations and experiments showed the V_(0.1)W_(0.9)N_(1.5) had great metallic features and large work functions,contributing a faster photo-generated carrier transfer and less recombination,finally facilitating a great performance in cocatalyst for syngas production in photoreforming *** work provides an approach to synthesizing novel transition metal nitrides for photocatalysis.

关键词： photocatalysis syngas formic acid cocatalyst solid solution

Combining serum cystatin C with creatinine, a new definition of contrast-induced acute kidney injury and its clinical implications

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中国循环杂志 2016年第Z1期31卷 -页

作者： tuo zhang Weifeng zhang Linghong Shen Ben He Renji Hospital Shanghai Jiaotong University School of Medicine Shanghai China

Adsorption mechanism of different coal ranks under variable temperature and pressure conditions

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Journal of China University of Mining and Technology 2008年第3期18卷 395-400页

作者： zhang qing-ling Xi＇ an Branch of China Coal Research Institute Xi＇ an Shaanxi 710054 China

Variable temperature and pressure adsorption tests were conducted on four coal samples with different coal ranks, under simulated temperatures and pressures corresponding to coal reservoirs at different depths. The regularity of the variation in the amounts of adsorption by coals under variable temperature and pressure and 30 ℃ isothermal conditions are compared and the adsorption characteristics of coal under the composite effect of temperature and pressure were obtained. The adsorption test and data processing method of coal under variable temperature and pressure are presented and the effect of the mechanism of temperature and pressure on the adsorption capacity of coal has been studied. The research results are of significant importance in the investigation of coalbed methane storage mechanism and for the prediction of the amounts of coalbed methane at various depths.

关键词： coal variable temperature and pressure test adsorotion characteristics