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Because increasing requirements of fuzzy spatiotemporal applications are attracting much attention from both academia and industry, it is challenging to model fuzzy spatiotemporal data and effectively operate them. However, various researches are studied in traditional databases that impose strict restrictions, and relatively little work has been carried out in modeling and operating fuzzy spatiotemporal data in XML. In this paper, we propose a novel approach to model fuzzy spatiotemporal data based on XML. On the basis of the model, we investigate how to represent fuzzy spatiotemporal data in XML documents and extend the XML schema so that it is possible to describe fuzzy spatiotemporal data and capture the structural information of fuzzy spatiotemporal XML documents. Furthermore, we give algorithms for fuzzy operations, containing node operations and topological relationship operations. Finally, we apply our model in meteorological events.

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Representing and identifying the topological relations between fuzzy spatiotemporal regions over time have an important significance in reasoning fuzzy spatiotemporal relations. The research issue of topological relations between fuzzy regions over time has attracted a lot of attention in the recent years. However, modeling topological relations needs to be further developed and it is still an open issue. In this paper, we extend the 9-Intersection model to establish a model for identification of topological relations between fuzzy spatiotemporal regions over time, and use extended intersection matrix to identify all possible topological relations. On the basis of our topological relation model, we extend two-dimensional Egg/Yolk model to three-dimensional space and calculate the corresponding intersection matrixes of each topological relations. Furthermore, after investigation of topological complexity and topological distance based on our proposed topological relation model, we propose a comprehensive conceptual neighborhood graph of the topological relations implemented on MATLAB.

A cognitive radio network with classified Secondary Users (SUs) is considered. There are two types of SU packets, namely, SU1 packets and SU2 packets, in the system. The SU1 packets have higher priority than the SU2 packets. Considering the diversity of the SU packets and the real-time need of the interrupted SU packets, a novel spectrum allocation strategy with classified SUs and impatient packets is proposed. Based on the number of PU packets, SU1 packets, and SU2 packets in the system, by modeling the queue dynamics of the networks users as a three-dimensional discrete-time Markov chain, the transition probability matrix of the Markov chain is given. Then with the steady-state analysis, some important performance measures of the SU2 packets are derived to show the system performance with numerical results. Specially, in order to optimize the system actions of the SU2 packets, the individually optimal strategy and the socially optimal strategy for the SU2 packets are demonstrated. Finally, a pricing mechanism is provided to oblige the SU2 packets to follow the socially optimal strategy.