本文较为详细地介绍了自Van der Waals状态方程以来所发展的若干典型的状态方程,并对各类型的状态方程进行了评价。但到目前为止还没有一种状态方程能对任何物质在很大范围内都是通用的。特别对量子流体及某些强极性物质,任何状态方程...本文较为详细地介绍了自Van der Waals状态方程以来所发展的若干典型的状态方程,并对各类型的状态方程进行了评价。但到目前为止还没有一种状态方程能对任何物质在很大范围内都是通用的。特别对量子流体及某些强极性物质,任何状态方程都还有困难。当前的办法仍是将若干类状态方程同时并用,在不同场合选择最合适的方程使用。因此本文对于状态方程的详细的综述可以为工程设计及从事这方面研究的人员提供有价值的参考。展开更多
提出了约束条件下(目标防御系统的威胁)对运动目标纯方位定位的观测器轨迹优化问题;建立了该条件下观测器轨迹优化模型,性能指标函数的选取是基于Fisher信息矩阵(Fisher Information Matrix,FIM)行列式的最大化,运用遗传算法解该优化问...提出了约束条件下(目标防御系统的威胁)对运动目标纯方位定位的观测器轨迹优化问题;建立了该条件下观测器轨迹优化模型,性能指标函数的选取是基于Fisher信息矩阵(Fisher Information Matrix,FIM)行列式的最大化,运用遗传算法解该优化问题得到优化轨迹;最后采用高斯粒子滤波估计目标状态.为了说明优化轨迹对定位效果的影响,分别给定直线运动和蛇行机动两类轨迹,并在无威胁约束和有威胁约束的情况下,同优化轨迹定位效果作比较.Monte-Carlo仿真结果表明:优化轨迹的定位精度优于蛇行机动和直线运动;对于不同威胁度下的优化轨迹,威胁越小对应的定位精度越高.展开更多
Making use of Weierstrass＇s theorem and Chebyshev＇s theorem and referring to the equations of state of the scaled-particle theory and the Pereus-Yevick integration equation, we demonstrate that there exists a sequen...Making use of Weierstrass＇s theorem and Chebyshev＇s theorem and referring to the equations of state of the scaled-particle theory and the Pereus-Yevick integration equation, we demonstrate that there exists a sequence of polynomials such that the equation of state is given by the limit of the sequence of polynomials. The polynomials of the best approximation from the third order up to the eighth order are obtained so that the Carnahan-Starling equation can be improved successively. The resulting equations of state are in good agreement with the simulation results on the stable fluid branch and on the metastable fluid branch.展开更多
The present paper discusses a design method for the head position in a Hard Disk Drive （HDD） control system. In the HDD control system, the sampling interval of the head position is constrained because of the hardwa...The present paper discusses a design method for the head position in a Hard Disk Drive （HDD） control system. In the HDD control system, the sampling interval of the head position is constrained because of the hardware specifications, but the hold interval of the control input is not constrained. In the present study, a multirate control system is designed, in which the sampling and the hold intervals are not equal. A multirate control law, which stabilizes a closed-loop system, is extended using newly introduced parameters such that the sample response of the plant output is maintained. Furthermore, intersample ripples in the steady state are eliminated using the new design parameters, which can be selected independently of the sample response. As a result, the intersample response can be improved independently of the sample response. The proposed method is applied to a benchmark problem of an HDD system, and its effectiveness is demonstrated.展开更多
The lack of standard to electronic circuits modeling made possible the development of many tools and modeling languages for electronic circuits. In this way, several tools to be used on different descriptions stage of...The lack of standard to electronic circuits modeling made possible the development of many tools and modeling languages for electronic circuits. In this way, several tools to be used on different descriptions stage of the designs are necessary. This paper presents a tool called SF^2HDL （Stateflow to Hardware Description Language or State Transition Table） that translates a finite state machine on state transition diagram representation, described by Stateflow tool, into an input file standard for TABELA program or into a file behavioral VHDL （Very High Speed Integrated Circuits Hardware Description Language） directly. The TABELA program was used to optimization this finite state machine. After that, the TAB2VHDL program was used to generate the VHDL code on register transfer level, what permits comparisons with results obtained by synthesis. The finite state machine must be described by Mealy model and the user can describe the machine on high level abstraction using all Simulink supports. The tool was very efficient on computational cost and it made translation of several cases, for the two VHDL description models. Every state machine translated was simulated and implemented on device EP2C20F484C7 using Quartus II environment.展开更多
文摘本文较为详细地介绍了自Van der Waals状态方程以来所发展的若干典型的状态方程,并对各类型的状态方程进行了评价。但到目前为止还没有一种状态方程能对任何物质在很大范围内都是通用的。特别对量子流体及某些强极性物质,任何状态方程都还有困难。当前的办法仍是将若干类状态方程同时并用,在不同场合选择最合适的方程使用。因此本文对于状态方程的详细的综述可以为工程设计及从事这方面研究的人员提供有价值的参考。
文摘提出了约束条件下(目标防御系统的威胁)对运动目标纯方位定位的观测器轨迹优化问题;建立了该条件下观测器轨迹优化模型,性能指标函数的选取是基于Fisher信息矩阵(Fisher Information Matrix,FIM)行列式的最大化,运用遗传算法解该优化问题得到优化轨迹;最后采用高斯粒子滤波估计目标状态.为了说明优化轨迹对定位效果的影响,分别给定直线运动和蛇行机动两类轨迹,并在无威胁约束和有威胁约束的情况下,同优化轨迹定位效果作比较.Monte-Carlo仿真结果表明:优化轨迹的定位精度优于蛇行机动和直线运动;对于不同威胁度下的优化轨迹,威胁越小对应的定位精度越高.
文摘Making use of Weierstrass＇s theorem and Chebyshev＇s theorem and referring to the equations of state of the scaled-particle theory and the Pereus-Yevick integration equation, we demonstrate that there exists a sequence of polynomials such that the equation of state is given by the limit of the sequence of polynomials. The polynomials of the best approximation from the third order up to the eighth order are obtained so that the Carnahan-Starling equation can be improved successively. The resulting equations of state are in good agreement with the simulation results on the stable fluid branch and on the metastable fluid branch.
文摘The present paper discusses a design method for the head position in a Hard Disk Drive （HDD） control system. In the HDD control system, the sampling interval of the head position is constrained because of the hardware specifications, but the hold interval of the control input is not constrained. In the present study, a multirate control system is designed, in which the sampling and the hold intervals are not equal. A multirate control law, which stabilizes a closed-loop system, is extended using newly introduced parameters such that the sample response of the plant output is maintained. Furthermore, intersample ripples in the steady state are eliminated using the new design parameters, which can be selected independently of the sample response. As a result, the intersample response can be improved independently of the sample response. The proposed method is applied to a benchmark problem of an HDD system, and its effectiveness is demonstrated.
文摘The lack of standard to electronic circuits modeling made possible the development of many tools and modeling languages for electronic circuits. In this way, several tools to be used on different descriptions stage of the designs are necessary. This paper presents a tool called SF^2HDL （Stateflow to Hardware Description Language or State Transition Table） that translates a finite state machine on state transition diagram representation, described by Stateflow tool, into an input file standard for TABELA program or into a file behavioral VHDL （Very High Speed Integrated Circuits Hardware Description Language） directly. The TABELA program was used to optimization this finite state machine. After that, the TAB2VHDL program was used to generate the VHDL code on register transfer level, what permits comparisons with results obtained by synthesis. The finite state machine must be described by Mealy model and the user can describe the machine on high level abstraction using all Simulink supports. The tool was very efficient on computational cost and it made translation of several cases, for the two VHDL description models. Every state machine translated was simulated and implemented on device EP2C20F484C7 using Quartus II environment.
