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The polynomial-like iterative equation for PM functions

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Science China Mathematics 2017年第8期60卷 1503-1514页

作者： LIU Liu gong XiaoBing Department of Mathematics Southwest Jiaotong University Department of Mathematics Neijiang Normal University

The polynomial-like iterative equation is an important form of functional equations, in which iterates of the unknown function are linked in a linear combination. Most of known results were given for the given function to be monotone. We discuss this equation for continuous solutions in the case that the given function is a PM(piecewise monotone) function, a special class of non-monotonic functions. Using extension method, we give a general construction of solutions for the polynomial-like iterative equation.

关键词： functional equation iteration non-monotonicity continuous solution leading coefficient problem

Sequential Fair Stackelberg Equilibria of Linear Strategies in Risk-Seeking Insider Trading

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Journal of Systems Science & Complexity 2018年第5期31卷 1302-1328页

作者： gong Fuzhou ZHOU Yonghui Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China Guizhou Normal University Guizhou 550001 China

This paper develops a sequential fair Stackelberg auction model in which each of the two risk-seeking insiders has an equal chance to be a leader or follower at each auction stage. The authors establish the existence, uniqueness of sequential fair Stackelberg equilibria （in short, FSE） when both insiders adopt linear strategies, and find that at the sequential equilibria such two insiders compete aggressively that cause the liquidity of market to drop, the information to be revealed and the profit to go down very rapidly while the trading intensity goes substantially high. Furthermore, the authors also give continuous versions of corresponding parameters in the sequential FSE in closed forms, as the time interval between auctions approaches to zero. It shows that such parameters go down or up approximately exponentially and all of the liquidity of market, information and profit become zero while the trading intensity goes to infinity. Some numerical simulations about the sequential FSE are also illustrated.

关键词： Continuous version insider trading risk-seeking sequential fair Stackelberg equilibria

Generating test data for both paths coverage and faults detection using genetic algorithms： multi-path case

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Frontiers of Computer Science 2014年第5期8卷 726-740页

作者： Yan ZHANG Dunwei gong School of Technology Mudanjiang Normal University Mudanjiang 157012 China School of Information and Electrical Engineering China University of Mining and Technology Xuzhou 221116 China

Generating test data that can expose the faults of the program is an important issue in software testing. Al- though previous methods of covering path can generate test data to traverse target path, the test data generated by these methods are difficult in detecting some low-probabilistic faults that lie on the covered paths. We present a method of generating test data for covering multiple paths to detect faults in this study. First, we transform the problem of cover- ing multiple paths and detecting faults into a multi-objective optimization problem with constraint, and construct a mathe- matical model for it. Then, we give a strategy of solving the model based on a weighted genetic algorithm. Finally, we ap- ply our method to several real-world programs, and compare it with several methods. The experimental results confirm that the proposed method can more efficiently generate test data that not only traverse the target paths but also detect faults lying in them than other methods.

关键词： software testing multiple paths coverage faultsdetection multi-objective optimization

Delay-dependent robust H_∞ control for uncertain discrete time-delay fuzzy systems

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Journal of Systems Engineering and Electronics 2009年第2期20卷 354-362页

作者： gong Cheng Su Baoku Coll. of Nuclear Science and Technology Harbin Engineering Univ. Harbin 150001 P. R. China Space Control and Inertial Technology Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

The robust H∞ control problem of norm bounded uncertain discrete Takagi-Sugeno （T-S） fuzzy systems with state delay is addressed. First, by constructing an appropriate basis-dependent Lyapunov-Krasovskii function, a new delay-dependent sufficient condition on robust H∞-disturbance attenuation is presented, in which both robust stability and prescribed H∞ performance are guaranteed to be achieved. Then based on the condition, a delay-dependent robust Hoo controller design scheme is developed in term of a convex algorithm. Finally, examples are given to illustrate the effectiveness of the proposed method.

关键词： discrete T-S fuzzy control delay-dependent robust H∞ control basis-dependent Lyapunov-Krasovskii function

Multi-objective optimization in quantum parameter estimation

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Science China(Physics,Mechanics & Astronomy) 2018年第4期61卷 30-35页

作者： BeiLi gong Wei Cui School of Automation Science and Engineering South China University of Technology

We investigate quantum parameter estimation based on linear and Kerr-type nonlinear controls in an open quantum system, and consider the dissipation rate as an unknown parameter. We show that while the precision of parameter estimation is improved,it usually introduces a significant deformation to the system state. Moreover, we propose a multi-objective model to optimize the two conflicting objectives:(1) maximizing the Fisher information, improving the parameter estimation precision, and(2)minimizing the deformation of the system state, which maintains its fidelity. Finally, simulations of a simplified ε-constrained model demonstrate the feasibility of the Hamiltonian control in improving the precision of the quantum parameter estimation.

关键词： quantum parameter estimation Fisher information multi-objective optimization

Tropical cyclone genesis over the western north Pacific in La Ni?a decay summers: Comparison between 2018 and 2021

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Science China Earth Sciences 2024年第10期67卷 3098-3109页

作者： Yunyun LIU Zhensong gong China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China

As the primary interannual signal of variability in the tropical ocean-atmosphere interaction, the El Ni?o-Southern Oscillation has a considerable impact on tropical cyclone(TC) activity over the western North Pacific(WNP). Both 2018 and2021 were La Ni?a decay years, but TC activity over the WNP during the two summers(June–August) showed notable differences. In 2018, summer TC activity was unusually high with a total of 18 TCs, and the region of TC genesis was mainly in the central and eastern WNP. In contrast, only 9 TCs were generated in summer 2021, and the region of TC genesis was primarily in the western WNP. By comparing the characteristics of the large-scale environmental conditions over the regions of TC genesis, the thermal factors of the tropical oceans, and the activity of the Madden-Julian Oscillation(MJO), this study revealed the possible causes for the marked differences in TC genesis over the WNP during the two summers, which both had a similar background of La Ni?a decay. The Indian Ocean Basin Mode(IOBM) transitioned of a cold anomaly in the winter of 2017/2018and persisted until summer 2018. At the same time, the Pacific Meridional Mode(PMM) maintained a positive phase, leading to eastward and northward displacement of the Western Pacific Subtropical High in summer, and eastward extension of the tropical monsoon trough, which presented conditions conducive to TC genesis over the Northwest Pacific. Moreover, the days when the MJO stagnated in phases 5 and 6 in the summer of 2018 increased by approximately 150% relative to climatological state,providing dynamic conditions favorable for TC formation. In 2021, the IOBM quickly turned to a warm anomaly in March and persisted until summer, whereas the PMM became a negative phase in January and remained so until summer. At the same time,the MJO stagnated in phases 2 and 3 for up to 47 days, with the center of convection located over the western Maritime Continent, producing conditions unconducive to TC ge

关键词： Tropical cyclone La Nina events Indian Ocean Basin Mode Pacific Meridional Mode Madden-Julian Oscillation Western Pacific Subtropical High Monsoon trough

SURFACE SELF-DIFFUSION ANISOTROPY OF TUNGSTEN ATOMS ON W(112) PLANE

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Chinese Physics Letters 1990年第12期7卷 537-540页

作者： gong Yunming Department of Radio-Electronics Peking UniversityBeijing 100871

Surface self-diffusion anisotropy of tungsten on W(112)plane has been measured along(Ⅱ)and across(丄)channels existed on this plane by using the field emission fluctuation method in two forms of the *** the round probehole the thermal activation energy E=13.0kcal,and the prefactor of the surface self-diffusion coefficient Dq=^.5X 70_7cm2s-1;in the long narrow rectangular slit,E(Ⅱ)=13.2kcal,D0(Ⅱ)=7.1×10-7crr^and E(丄)=6.2kcal,Do(丄)=1.8×10^(-9)cm^(2)s^(-1) at T=*** experimental data suggest that a W atom diffusing across channels should not climb over the channel wall,which would certainly require a much higher activation energy,but instead,displace an atom in the *** process reqwes a much smaller activation energy;however,since it involves concerted motion of at least two atoms,it will also have a much smaller prefactor.

关键词： activation diffusion SURFACE

Full Power Hydraulic Brake System Based on Double Pipelines for Heavy Vehicles

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Chinese Journal of Mechanical Engineering 2011年第5期24卷 790-797页

作者： gong Mingde WEI Hailong College of Mechanical Science and Engineering Jilin University Changchun 130025 China

The hydraulic caliper disc brake system with air-over-oil is widely adopted at present for heavy vehicles,which makes use of air pressure system propelling the hydraulic pressure system acting on friction plates divided and combined for *** are some disadvantages such as pneumatic components failure,dust polluted and produce lots of heat in hydraulic caliper disc brake ***,considering the demands of the high speed,heavy weight,heavy load and fast brake of heavy vehicles,the full power hydraulic brake system based on double pipelines for heavy vehicles is designed and analyzed in this *** scheme of the full power hydraulic brake system,in which the triloculare cylinder is controlled by dual brake valve,is adopted in the brake *** full power hydraulic brake system can accomplish steering brake,parking brake and emergent brake for heavy ***,electronic control system that is responsible for coordinating the work of hydraulic decelerator and hydraulic brake system is developed for different speed *** on the analysis of the influence of composed unit and connecting pipeline on braking performance,the nonlinear mathematic model is established for the full power hydraulic brake *** braking completion time and braking pressure in braking performance of the double-pipeline steering brake and parking brake are discussed by means of simulation experiments based on Matlab/Simulink,and the simulation results prove that the braking performance of steering brake and parking brake meets the designing requirement of the full power hydraulic brake ***,the test-bed experiments of the brake system for heavy vehicles are carried *** experimental data prove that the braking performance achieves the goal of the design,and that the full power hydraulic brake system based on double pipelines can effectively enhance braking performance,ensure braking reliability and security for heavy vehicles.

关键词： heavy vehicle full power hydraulic brake system double-pipeline brake triloculare cylinder braking performance

Effect of aspect ratio on triaxial compression of multi-sphere ellipsoid assemblies simulated using a discrete element method

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Particuology 2017年第3期15卷 49-62页

作者： Jian gong Jun Liu State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

Here, we present a numerical investigation of the mechanical behavior of ellipsoids under triaxial com- pression for a range of aspect ratios. Our simulations use a multi-sphere approach in a three-dimensional discrete element method. All assemblies were prepared at their densest condition, and triaxial compres- sion tests were performed up to extremely large strains, until a critical state was reached. The stress-strain relationship and the void ratio-strain behavior were evaluated. We found that the stress-dilatancy rela- tionship of ellipsoids with different aspect ratios could be expressed as a linear equation. In particular, the aspect ratio influenced the position of the critical state lines for these assemblies. Particle-scale char- acteristics at the critical state indicate that particles tend to be flat lying, and the obstruction of particle rotation that occurs with longer particles affects their contact mechanics. Lastly, anisotropic coefficients related to aspect ratio were investigated to probe the microscopic origins of the macroscopic behavior. A detailed analysis of geometrical and mechanical anisotropies revealed the microscopic mechanisms underlying the dependency of peak and residual strengths on aspect ratio.

关键词： EllipsoidsAspect ratio DEM Triaxial compression Particle shape Macro-micro response