The function projective synchronization of discrete-time chaotic systems is presented. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate funct...The function projective synchronization of discrete-time chaotic systems is presented. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate function projective synchronization （FPS） of discrete-time chaotic systems with uncertain parameters. With the aid of symbolic-numeric computation, we use the proposed scheme to illustrate FPS between two identical 3D Henon-like maps with uncertain parameters. Numeric simulations are used to verify the effectiveness of our scheme.展开更多
Network processors are used in the core node of network to flexibly process packet streams. With the increase of performance, the power of network processor increases fast, and power and cooling become a bottleneck. A...Network processors are used in the core node of network to flexibly process packet streams. With the increase of performance, the power of network processor increases fast, and power and cooling become a bottleneck. Architecture-level power conscious design must go beyond low-level circuit design. Architectural power and performance tradeoff should be considered at the same time. Simulation is an efficient method to design modem network processor before making chip. In order to achieve the tradeoff between performance and power, the processor simulator is used to design the architecture of network processor. Using Netbeneh, Commubench benchmark and processor simulator-SimpleScalar, the performance and power of network processor are quantitatively evaluated. New performance tradeoff evaluation metric is proposed to analyze the architecture of network processor. Based on the high performance lnteI IXP 2800 Network processor eonfignration, optimized instruction fetch width and speed ,instruction issue width, instruction window size are analyzed and selected. Simulation resuits show that the tradeoff design method makes the usage of network processor more effectively. The optimal key parameters of network processor are important in architecture-level design. It is meaningful for the next generation network processor design.展开更多
In order to achieve highly accurate and efficient numerical calculations of structural dynamics, time collocation method is presented. For a given time interval, the numerical solution of the method is approximated by...In order to achieve highly accurate and efficient numerical calculations of structural dynamics, time collocation method is presented. For a given time interval, the numerical solution of the method is approximated by a polynomial. The polynomial coefficients are evaluated by solving algebraic equation. Once the polynomial coefficients are evaluated, the numerical solutions at any time in the interval can be easily calculated. New formulae are derived for the polynomial coefficients,which are more practical and succinct than those previously given. Two structural dynamic equations are calculated by the proposed method. The numerical solutions are compared with the traditional fourth-order Runge-Kutta method. The results show that the method proposed is highly accurate and computationally efficient. In addition, an important advantage of the method is the simplicity in software programming.展开更多
Gears play an important role in mechanical engineering because of their moment and speed transmission possibilities. Design and optimization of a complete gearbox provide many requirements to the designer. The complex...Gears play an important role in mechanical engineering because of their moment and speed transmission possibilities. Design and optimization of a complete gearbox provide many requirements to the designer. The complex gearbox model consists of many machine elements （shafts, gears, bearings, housing, seals, and shaft-hub connections）. The gearbox must be understood as a system with interactive parts. Next to the calculation of kinematics, load capacities and life times of single elements, aspects of load distribution and efficiency and noise excitation of gearboxes become important. The wide range of knowhow needed mostly cannot be covered by a small number of engineers. The development of automated calculation routines with understandable and comprehensive results is the goal for these research projects that lead to sottware-realizing solutions for engineers to efficiently design, calculate, optimize and verify gearboxes with minimal resources in terms of calculation experts and time.展开更多
It is scientifically important science value and engineering promising to develop the buoyancy-lift integrated hybrid airship for high attitude platform.Through the numerical method,a new tandem wings hybrid airship w...It is scientifically important science value and engineering promising to develop the buoyancy-lift integrated hybrid airship for high attitude platform.Through the numerical method,a new tandem wings hybrid airship with both higher utility value and economy efficiency was obtained and its total performance and technical parameters were analyzed in detail.In order to further improve the lift-drag characteristics,we implemented the optimization design for aerodynamic configuration of tandem wings hybrid airship via the response surface method.The results indicate that the tandem wings hybrid airship has considerable volume efficiency and higher aerodynamic characteristics.After optimization,the lift-drag ratio of this hybrid airship was increased by 6.08%.In a given gross lift condition,tandem wings hybrid airship may provide more payload and specific productivity.Furthermore,the size of tandem airship is smaller so the demand for skin flexible materials can be reduced.Results of this study could serve as a new approach to designing buoyancy-lifting integrated hybrid airship.展开更多
The operating parameters such as the internal quantum efficiency （η）, internal loss （α） and transparent threshold current density （J0） of double quantum well laser diodes were investigated and identified using...The operating parameters such as the internal quantum efficiency （η）, internal loss （α） and transparent threshold current density （J0） of double quantum well laser diodes were investigated and identified using the program, Integrated System Engineering-Technical Computer Aided Design （ISE-TCAD）. Various thicknesses （6, 7, 8, 10, 12 rim） of AlxInyGa1-x-yN barriers with （3 nm） Al0.08In0.08Ga0.84N wells as an active region were studied. The lowest threshold current （lth）, and the highest output power （Pop） were 116 mA and 196 mW respectively, at barriers thickness of 6 nm, Al mole fraction of 10% and In mole fraction of 1%, at an emission wavelength of 359.6 nm.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.10735030 and 90718041Shanghai Leading Academic Discipline Project under Grant No.B412+1 种基金Zhejiang Provincial Natural Science Foundations of China under Grant No.Y604056,Doctoral Foundation of Ningbo City under Grant No.2005A61030Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT0734
文摘The function projective synchronization of discrete-time chaotic systems is presented. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate function projective synchronization （FPS） of discrete-time chaotic systems with uncertain parameters. With the aid of symbolic-numeric computation, we use the proposed scheme to illustrate FPS between two identical 3D Henon-like maps with uncertain parameters. Numeric simulations are used to verify the effectiveness of our scheme.
基金Sponsored by the National Defence Research Foundation of China(Grant No.413460303).
文摘Network processors are used in the core node of network to flexibly process packet streams. With the increase of performance, the power of network processor increases fast, and power and cooling become a bottleneck. Architecture-level power conscious design must go beyond low-level circuit design. Architectural power and performance tradeoff should be considered at the same time. Simulation is an efficient method to design modem network processor before making chip. In order to achieve the tradeoff between performance and power, the processor simulator is used to design the architecture of network processor. Using Netbeneh, Commubench benchmark and processor simulator-SimpleScalar, the performance and power of network processor are quantitatively evaluated. New performance tradeoff evaluation metric is proposed to analyze the architecture of network processor. Based on the high performance lnteI IXP 2800 Network processor eonfignration, optimized instruction fetch width and speed ,instruction issue width, instruction window size are analyzed and selected. Simulation resuits show that the tradeoff design method makes the usage of network processor more effectively. The optimal key parameters of network processor are important in architecture-level design. It is meaningful for the next generation network processor design.
基金Supported by Liu Hui Applied Mathematics Center of Nankai University-Tianjin University( No. H10124).
文摘In order to achieve highly accurate and efficient numerical calculations of structural dynamics, time collocation method is presented. For a given time interval, the numerical solution of the method is approximated by a polynomial. The polynomial coefficients are evaluated by solving algebraic equation. Once the polynomial coefficients are evaluated, the numerical solutions at any time in the interval can be easily calculated. New formulae are derived for the polynomial coefficients,which are more practical and succinct than those previously given. Two structural dynamic equations are calculated by the proposed method. The numerical solutions are compared with the traditional fourth-order Runge-Kutta method. The results show that the method proposed is highly accurate and computationally efficient. In addition, an important advantage of the method is the simplicity in software programming.
文摘Gears play an important role in mechanical engineering because of their moment and speed transmission possibilities. Design and optimization of a complete gearbox provide many requirements to the designer. The complex gearbox model consists of many machine elements （shafts, gears, bearings, housing, seals, and shaft-hub connections）. The gearbox must be understood as a system with interactive parts. Next to the calculation of kinematics, load capacities and life times of single elements, aspects of load distribution and efficiency and noise excitation of gearboxes become important. The wide range of knowhow needed mostly cannot be covered by a small number of engineers. The development of automated calculation routines with understandable and comprehensive results is the goal for these research projects that lead to sottware-realizing solutions for engineers to efficiently design, calculate, optimize and verify gearboxes with minimal resources in terms of calculation experts and time.
基金supported by the National High-Tech Research and Development Program of China (Grant No. 863-2007AA11Z243)Foundation for Basic Research of Northwestern Polytechnic University (Grant No.JC-201103)
文摘It is scientifically important science value and engineering promising to develop the buoyancy-lift integrated hybrid airship for high attitude platform.Through the numerical method,a new tandem wings hybrid airship with both higher utility value and economy efficiency was obtained and its total performance and technical parameters were analyzed in detail.In order to further improve the lift-drag characteristics,we implemented the optimization design for aerodynamic configuration of tandem wings hybrid airship via the response surface method.The results indicate that the tandem wings hybrid airship has considerable volume efficiency and higher aerodynamic characteristics.After optimization,the lift-drag ratio of this hybrid airship was increased by 6.08%.In a given gross lift condition,tandem wings hybrid airship may provide more payload and specific productivity.Furthermore,the size of tandem airship is smaller so the demand for skin flexible materials can be reduced.Results of this study could serve as a new approach to designing buoyancy-lifting integrated hybrid airship.
基金conducted under Science Fund,Cycle 2007,of The Ministry of Science,Technology and Innovation,MalaysiaThe financial support from Universiti Sains Malaysia is gratefully acknowledged
文摘The operating parameters such as the internal quantum efficiency （η）, internal loss （α） and transparent threshold current density （J0） of double quantum well laser diodes were investigated and identified using the program, Integrated System Engineering-Technical Computer Aided Design （ISE-TCAD）. Various thicknesses （6, 7, 8, 10, 12 rim） of AlxInyGa1-x-yN barriers with （3 nm） Al0.08In0.08Ga0.84N wells as an active region were studied. The lowest threshold current （lth）, and the highest output power （Pop） were 116 mA and 196 mW respectively, at barriers thickness of 6 nm, Al mole fraction of 10% and In mole fraction of 1%, at an emission wavelength of 359.6 nm.
