线性微分理想的维数

微分理想的维数是微分代数中一个重要的概念 ,利用 Hilbert多项式来计算微分理想的维数 ,计算量较大 .本文通过吴微分特征列算法和偏微分方程的形式解理论 ,给出了线性微分理想的维数多项式、维数的定义和算法 ,且算法容易实现 .

多项式代数上的微分理想

设k[x]是特征为零的域k上的一元多项式环.研究了k[x]上带权的非零单项式微分算子对应的微分理想的性质,利用矩阵求最大公因式的方法,确定了由一个多项式生成的微分理想作为通常意义上的理想时的生成元.

MV-代数的(→,)-微分

在MV-代数上引入了(→,)-微分,研究了MV-代数(→,)-微分的性质。定义并研究了正则(→,)-微分,并讨论了MV-代数的布尔中心上的(→,)-微分的一些性质。给出了中心主微分的概念,用中心主微分讨论了(→,)-微分与MV-代数其他微分之间的关系。并用中心主微分的不动点之集刻画了Boole代数。最后,定义并研究了微分MV-代数的微分理想,并讨论了正则微分MV-代数所有的微分理想组成的集合ID(A)的代数结构。

微分环上微分多项式的基本性质

将Ritt理论中有关微分域上的微分多项式系统的基本性质移植到微分环上 ,给出了用于计算任一微分多项式关于一个升列的余式的余式公式 ,并讨论了由微分多项式系统在添加新的多项式后形成的新的完备理想与原理想的关系 .

Registration of image feature points using differential evolution

This paper introduces a robust global nonlinear optimizer—differential evolution(DE),which is a simple evolution algorithm to search for an optimal transformation that makes the best alignment of two sets of feature points.To map the problem of matching into the framework of DE,the objective function is proportional to the registration error which is measured by Hausdorff distance,while the parameters of transformation are encoded in floating-point as the functional variables.Three termination criteria are proposed for DE.A simulation of 2-dimensional point sets and a similarity transformation are presented to compare the robustness and convergence properties of DE with genetic algorithm’s (GA).And the registration of an object and its contour model have been demonstrated by using of DE to natural images.

Properties and interfacial microstructure of cement-based materials with composite micro-grains

Silica fume, fly ash and nano-fiber mineral materials (NR powder) are employed to incorporate into cement-based materials. According to the grain grading mathematical model of cement-based materials, two packing systems, namely, spherical grading system and nano-fiber reinforced system were designed. Properties and interfacial microstructure of the two systems were studied according to secondary interface theory. It was shown that nano-fiber mineral materials can improve the grain grading of the admixture, increase the density of the system, improve the microstructure of the interface and the hardened paste, and enhance the uniformity of cement-based materials mixed with composite micro-grains and greatly increase their wearable rigidity and flexure strength. In this paper, two kinds of interface models, including spherical grain model and nano-fiber reinforced interface model of the cement-based materials mixed with composite micro-grains, were brought forward.

Monadic MV-代数上的微分

在Monadic MV-代数(M,■)上引入并研究了M-微分。定义并研究了Monadic MV-代数(M,■)上的强M-微分和正则M-微分,利用强M-微分,给出了一个MV-代数成为布尔代数的等价刻画,并给出了正则M-微分成为保序M-微分的等价刻画。进一步地,在Monadic MV-代数(M,■)上定义不动点集合Fd■,证明了若d为保序微分时,Monadic MV-代数上的不动点之集为M的格理想。随后,在Monadic MV-代数上定义并研究了可加微分,从而得到了一些关于可加微分的重要性质。最后,在微分Monadic MV-代数(M,■,d)上定义了Monadic微分理想,并对其进行了刻画,而且研究了(M,■,d)上所有Monadic微分理想组成的集合ID(M)的代数结构。