描述

These descriptors are invariant under translation, rotation, and scale, but variant under affine and projective transformation. Five-point invariant descriptor is a contour presentation method and consists of a series of five-point invariants.

这些描述子在相似变换下，能够保持平移、旋转、尺度不变，但在仿射投影变换情况下则不再保持不变性。五点不变量描述子也是一种描述轮廓的方法。

After a brief introduction to the formal description technique LOTOS and ISO/ OSI session layer standard, this paper specifies the OSI session layer in detail and an architectural model and some important models are given.

本文通过对形式化描述技术LOTOS语言和ISO/OSI会话层标准的简要介绍，较详细地讨论了用LOTOS语言对OSI会话层的形式化规范描述，给出了其结构模型及一些重要的模块结构描述。

It describes complex configuration process and usage and diagnosis methods of complex device and represents device characteristics in graphics mode base on software module and extended XDDL with self-define tags.

并针对XDDL在描述复杂设备的复杂配置、诊断过程和使用方法描述以及可视化描述等方面的不足，提出了一种扩展基于XDDL的设备描述的方法。