普适计算中的上下文及纯方位定位模型

室内高精度定位问题是普适计算中位置感知研究的首要难题。介绍了普适计算中上下丈的概念，就上下文中的位置问题进行了探讨。通过分析目前室内定位中存在的问题，给出了一种利用红外无源定位技术定位的模型，通过测得的方位角计算出用户的位置。对该模型进行了证明，证明结果显示该模型可以定出目标的准确位置。

Context in ubiquitous computing and pure azimuth location model

High precision in indoor location is the preliminary problem of location-aware research in ubiquitous computing. The concept of context in ubiquitous computing is firstly introduced. In terms of the "where" in context, some issues are argued. By analyzing the problems in indoor locating system, a model about infrared passive location is then given, and this model can determine the user's position according to the azimuth angles that have been measured. It reaches the high precision in indoor location system. At last, it is proved that the model can get the accurate position of a target.