实域粗糙集理论及属性约简

本文引入属性和属性子集广义重要度的概念以及空间中的广义近邻关系,提出广义近邻关系下的实域粗糙集扩展模型．在实域粗糙集理论中,利用广义近邻关系在全局中划分相容模块,构成集合的下、上近似,避免了Pawlak粗糙集必须量化数据的麻烦．另外,本文给出了实域粗糙集的属性约简定义和一种贪心算法,分析了约简属性集合的质量．最后,通过实例验证了本文理论和方法的正确性和有效性．

交换环的实V-赋值与亚序

在带有单位元的交换环上,引入了V-赋值与亚序间的相容性,并得出了一些性质。在此基础上,对环的实V-赋值进行了讨论,从而推广了实Manis赋值理论中许多的结论。

阿廷——布尔巴基学派的先驱

阿廷是20世纪最伟大的数学家之一。他完成经典类域论并指出其推广的方向。他是抽象代数学的奠基者之一,创立辫子理论及实域理论。他完全解决两个半希尔伯特问题,是布尔巴基学派的思想先驱,培养了许多大数学家。本文对阿廷的生平、工作及影响进行系统的介绍。

Comparison of convective parameterizations in RegCM4 experiments over China with CLM as the land surface model

in the latest version of the international Centre for Theoretical Physics＇ regional climate model, RegCM4, CLM was introduced as a new land surface scheme. The performance over China of RegCM4-CLM with different convection schemes is analyzed in this study, based on a series of short- term experiments.The model is driven by ERA-Interim data at a grid spacing of 25 km.The convection schemes employed are： Emanuel; Grell; Emanuel over land and Grell over ocean; Grell over land and Emanuel over ocean; and Tiedtke. The simulated mean surface air temperature and precipitation in December-February-January and June-July-August are compared against observation. In general, better performance of Emanuel is found both for temperature and precipitation, and in both seasons. Thus, the model physics of CLM and Emanuel for the land surface processes and convection, respectively, are recommended for further application of RegCM4 over the China region. The de^ciencies that remain in the model arealso outlined and discussed.