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There are a lot of spatio-temporal data in the real world. The management of spatio-temporal data has proposed higher requirements for spatio-temporal modeling， which has become a hotspot in many fields. UML is a widely used unified modeling language， and the spatio-temporal extension model based on UML has become an important spatio-temporal modeling approach of many fields. This paper presents a spatio-temporal UML model， which can deal with a variety of spatio-temporal topology relationships (including RCC-8 spatial topology and Allen-13 temporal topology relationships) and the complex semantic relations among the spatio-temporal objects. In addition， this paper provides a formal definition and semantic interpretation of spatio-temporal UML model. Finally， an example of cadastral change is provided to demonstrate the feasibility and practicability of the proposed model. [ABSTRACT FROM AUTHOR]

Sunshine has played a critical role in trajectory analysis. It is of great significance to design an algorithm that could not only estimate the sunshine information of the trajectory effectively, but also remove the redundant points and keep the necessary sunshine-based information. This paper proposes a sunshine based trajectory simplification algorithm, which considers the urban trajectory character, to solve the challenges of trajectory analyzing in various sunshine related scenarios. On the one hand, an orientation model is established to abstract the relationship between trajectory and sunlight. On the other hand, a sunshine related trajectory simplification model is proposed, and the genetic algorithm is applied to find the points that need to be reserved. Finally, the real-world data of Minneapolis, US, is used for experiment. The results demonstrate that the proposed algorithm can effectively reduce the number of turning points in the trajectories under the control of bound Tmax. [ABSTRACT FROM AUTHOR]