Mobile IM (Instant Messaging) users are more frequently online and offline than fixed users. It incurs large presence message traffic that significantly consumes the limited service resources. Some studies indicate that presence delayed update can effectively reduce the traffic. Firstly, we analyze presence update process and research presence distribution. Secondly, we use mathematical model t...

Visual object tracking is required in many tasks such as video compression, surveillance, automated video analysis, etc. mean shift algorithm is one of popular methods to this task and has some advantages comparing to other tracking methods. This method would not be appropriate in the case of large target appearance changes and occlusion; therefore target model update could actually improve thi...

Problem statement: Memoryless QN methods have been regarded effective techniques for solving large-scale problems that can be considered as one step limited memory QN methods. In this study, we present a scaled memoryless modified Symmetric Rank-One (SR1) algorithm and investigate the numerical performance of the proposed algorithm for solving large-scale unconstrained optimization problems. Ap...