中文摘要：

精度与程度是两个重要的量化指标，它们的结合双量化具有完备意义。本文将精度与程度进行复合，研究基于覆盖的精度与程度逻辑或粗糙集模型。首先，把等价类扩展为覆盖，利用元素的最小描述，提出基于覆盖的精度与程度逻辑或粗糙集模型；其次，给出该模型的上下近似、正域、负域及边界的定义，讨论一些相关的性质和定理；最后，实例分析验证了该模型的优越性。该模型更好地拓展了变精度覆盖粗糙集模型和程度覆盖粗糙集模型，对粗糙集区域的刻画更加准确。

英文摘要：

Precision and grade are two important indexes for quantitative research, the combination of double quantitative have complete significance. By compounding precision and grade, this paper researches covering rough set model based on logic-or operation of precision and grade. Firstly, the equivalence class was extended to covering, by employing the minimal descriptions of elements, and this paper proposes covering rough set model base on logic-or operation of precision and grade; Secondly, and some definitions are given in the model, for example, upper approximation, lower approximation, positive region, negative region and boundary region, some relevant properties and theorems are discussed and proved; Finally, example analyse explains the advantage of the present model. The covering grade rough set model and covering precise rouge set model are extended by the proposed model, and the characterization of rough region becomes more accurate.