可控受限多变量耦合系统的智能控制

针对可控受限多变量耦合系统,提出了一种基于对角递归神经网络(DRNN)整定的PID混合解耦控制。采用对角递归神经网络来辨识系统模型,进而对PID控制器参数进行整定,实现多变量解耦控制。通过对多变量耦合控制系统的设计和实时控制,实际控制结果达到了解耦控制的要求,并具有无超调、响应速度快、控制精度高等特点。     

改进DRNN用于纸张水分定量解耦控制

针对抄纸过程中纸机系统大滞后、非线性、时变且纸张的水分与定量之间存在严重耦合的问题,提出一种基于改进DRNN神经网络辨识的PID解耦控制器。该控制器利用改进DRNN对定量与水分参数的Jacobian信息辨识结果,自适应调整PID控制器的各项比例系数。仿真结果表明水分与定量之间相互影响很小,能较好实现对象的解耦控制,且适应能力强。实际运行结果表明,该算法的投入提高了控制精度,具有较强的鲁棒性。     

含有角联分支的通风网络平衡图研究

通风网络中的角联分支本身具有风流不稳定的特点。从通风网路图仅能看出角联分支风流方向的改变。通风网络平衡图在定量、直观反映通风网络的拓扑关系及各种性质方面,具有优越性。应用独立通路法画出含有角联分支的通风网络平衡图,可以直观地看出角联分支风流不稳定的变化情况,从而为研究角联分支对通风网络的影响提供更有效的方法。     

中轴变换图像处理算法的改进研究

介绍了一种改进的中轴变换算法。该算法修正了现存算法的缺点,可以快速去除二值图像中的冗余信息,准确抽取图像的单像素骨架,保留基本特征,特别是斜线和圆形焊盘特征。大量实验表明,该方法降低图像的复杂度,仅保留图像形状的拓扑信息,为后续处理提供理想的图像,提高整个系统的性能。     

Minimising the Number of Bends and Volume in 3-Dimensional Orthogonal Graph Drawings with a Diagonal Vertex Layout

A 3-dimensional orthogonal drawing of a graph with maximum degree at most 6, positions the vertices at grid-points in the 3-dimensional orthogonal grid, and routes edges along grid-lines such that edge routes only intersect at common end-vertices. Minimising the number of bends and the volume of 3-dimensional orthogonal drawings are established criteria for measuring the aesthetic quality of a given drawing. In this paper we present two algorithms for producing 3-dimensional orthogonal graph drawings with the vertices positioned along the main diagonal of a cube, so-called diagonal drawings. This vertex-layout strategy was introduced in the 3-BENDS algorithm of Eades et al. [Discrete Applied Math. 103:55–87, 2000]. We show that minimising the number of bends in a diagonal drawing of a given graph is NP-hard. Our first algorithm minimises the total number of bends for a fixed ordering of the vertices along the diagonal in linear time. Using two heuristics for determining this vertex-ordering we obtain upper bounds on the number of bends. Our second algorithm, which is a variation of the above-mentioned 3-BENDS algorithm, produces 3-bend drawings with n³+o(n³) volume, which is the best known upper bound for the volume of 3-dimensional orthogonal graph drawings with at most three bends per edge.     

Quasi-copulas and copulas on a discrete scale

In the paper the structure of quasi-copulas and copulas on a finite discrete scale is studied. The possibility of construction of quasi-copulas (copulas) from given values at diagonal points is investigated. Moreover, the problem of the uniqueness of the existence of a quasi–copula (copula) with given diagonal section is solved. Several examples are included.     

MIMO雷达稳健的发射波束形成算法

针对发射导向矢量存在未知误差的问题,该文提出了一种MIMO雷达稳健的发射波束形成算法(Robust Transmitting Beamforming, RTB)。该算法在稳健的接收波束形成算法的基础上,以最大化最差情况输出信干噪比为优化准则,对发射导向矢量误差做稳健的发射波束形成。RTB算法属于对角加载方法。仿真结果表明,相比于已有算法,RTB算法的稳健性更好、计算复杂度更低、收敛速度更快。     

Diagonal stability of a class of cyclic systems and its connection with the secant criterion

We consider a class of systems with a cyclic interconnection structure that arises, among other examples, in dynamic models for certain biochemical reactions. We first show that a “secant” criterion for local stability, derived earlier in the literature, is in fact a necessary and sufficient condition for diagonal stability of the corresponding class of matrices. We then revisit a recent generalization of this criterion to output strictly passive systems, and recover the same stability condition using our diagonal stability result as a tool for constructing a Lyapunov function. Using this procedure for Lyapunov construction we exhibit classes of cyclic systems with sector nonlinearities and characterize their global stability properties.     

Applications of equivalent circuit method to three-dimensional analysis of open-cycle diagonal type MHD generator

For analysis of an open-cycle diagonal type generator, a numerical method using a new three-dimensional equivalent circuit is proposed, in which the leakage resistance of the channel insulator surface, the boundary layer, the ion slip, the effect of the finite electrode segmentation, etc. are considered. Next, through the relation between the Hall voltage and the load current obtained by use of the equivalent circuit method, a suitable number of the space elements is determined. Further, when channel wall temperature is high, an insulating sidewall (ISW) generator is superior to a diagonal conducting sidewall (DCW) one, and inversely, when the temperature is low, the latter is superior to the former. When the values of the diagonal angle and the load factor are suitably selected, the ISW generator can give high performance characteristics comparing favorably with the Faraday type one, and moreover, the DCW one can give superior characteristics to the ISW and Faraday type ones when the wall temperature is low.