再生分辨矩阵与决策熵的不完备决策系统属性约简

为了有效地解决不完备决策系统的属性约简问题,提高属性约简的效率,提出了基于再生分辨矩阵与决策熵的不完备属性约简算法。该算法利用基于容差关系的分辨矩阵来计算相对核,通过再生分辨矩阵计算再生集和再生集属性来缩小加入约简集的条件属性选择范围,以再生集属性的分辨度和决策熵为依据,选择加入约简集的条件属性,并通过实例进行验证分析。结果表明,该算法适用于协调不完备决策系统与不协调不完备决策系统,能够有效地降低时间复杂度,并得到最优属性约简。

实现最佳煤炭产品结构的方法

为使全国各矿务局(矿、选煤厂)实现最佳煤炭产品结构,获得最大经济效益。本文提出用 C_n^1组合公式算出各企业可能出现的煤炭产品结构数 m,再利用'多边形找路线'或'再生矩阵法',求出 m 种产品结构各自的面貌(即有哪几种煤炭品种),分别计算经济效益后,进行比较,从中优选出经济效益最高的煤炭产品结构。

基于改进MCMC的疫情人群管控模型

基于改进的马尔可夫链蒙特卡罗方法,探寻人群管制方式下疫情的传播与演化规律。首先在经典SEIR模型的基础上,建立SEDIQR模型,使用马尔可夫链蒙特卡罗方法估计出模型的参数,通过Geweke方法对马氏链进行收敛诊断,并用基本再生矩阵理论推导出疫情的有效再生数表达式。然后用韩国的疫情数据进行实证分析,并进行管控力度分析。结果表明:模型得到的理论值与实际值吻合较好,有效再生数的变化趋势能够合理地反映疫情传播能力的变化;减小初始易感者数量和有效接触率均能够降低现有确诊人数和感染者人数的峰值和峰值时间,且能够缩短有效再生数降为1所需的时间,初始易感者数量和有效接触率都是影响疫情发展的重要敏感参数,同幅度地控制初始易感者的数量,相对于控制有效接触率,对于防控疫情具有更大的作用。新的人群管制方式下的疫情传播模型预测的结果比之前文献预测的要更准确一些。疫情的传播与演化规律对政府管理部门和相关医疗专家制定和修正防疫方案具有重要的参考价值,并且可为世界各国防御类似疫情提供理论依据。

An improved reduction algorithm based on the degree of attribute discernibility

This paper deals with the problem of attribute discernibility reduction and proposes some new concepts to rough set theory （RST） based on the discernibility matrix of Skowron, such as secondary core, regeneration matrix and the degree of attribute discernibility （DAD）. This paper puts forward an attribute reduction algorithm based on maximum discernibility degree, which opens up an effective way of gaining minimum attribute reduction of decision table. The efficacy of this algorithm has been verified by practical application in a diagnostic system of loader, which substantially decreases information gathering requirement and lowers the overall cost with no loss of accuracy.

Identification of complex compliance for regenerator in thermoacoustic resonator system

In thermoacoustic system,the characteristic of complex compliance of a regenerator has a great influence on energy stored and dissipation of the whole engine.In order to investigate the performance of regenerators with different matrix geometries and materials coupled with different acoustic systems,an experimental measurement and analysis method was presented.By measuring the resonant frequency,the complex compliance and quality factor of five kinds of matrix were experimentally analyzed respectively in the system of loudspeaker-driven thermoacoustic resonator(TAR)with different lengths.The experimental results show that the real part of complex compliance of the regenerator with pin-array has a maximum value among the measured matrixes and its quality factor is the largest(28.222)with the least dissipation factor of 0.035 4.So the pin-array matrix is testified to behave more excellently on the energy conversion than other matrixes.Compared with other factors the complex compliance of a regenerator contributes more to the performance of a thermoacoustic system.

Reproducing Kernel for D^2(Ω,ρ) and Metric Induced by Reproducing Kernel

An important property of the reproducing kernel of D2(Ω,ρ) is obtained and the reproducing kernels for D2(Ω,ρ) are calculated when Ω = Bn × Bn and ρ are some special functions.A reproducing kernel is used to construct a semi-positive definite matrix and a distance function defined on Ω×Ω.An inequality is obtained about the distance function and the pseudo-distance induced by the matrix.