Sharif Digital Repository

Wireless sensor network is composed of a large number of sensor nodes which are densely deployed to monitor the environment and collect information from physical events. There are different modelsfor sending collected data to users; one of them is query-driven models, in which according to user interest and via declarative queries collected data is delivered. Wireless sensor networks are energy constrained; regarding this issue, it is necessary to have an energy efficient design. Data aggregation or in network processing is one existing solution to reduce energy consumption. Data correlation or redundancy is also can be used with this method to save energy even more. In this thesis, an... 

In this work we present a surveillance video retrieval system based on Topic Models. We’ve shown that employing Dynamic Programming improve the effectiveness of Topic Model based retrival. In the other hand proposed method has the accuracy near to the low-level features based methods. Lightweight database is the major advantageous of propsed method over the low-level features based methods. In our work storage space occupied by database decreases from 42 MB to only 0.4 MB for the mit dataset. Moreover lightweight database strikingly speeded up the retrieval process, for example retrieval process in proposed method is about 24 times faster than low-level features based systems. Furthermore in...