deletions | additions       diff --git a/Human_Activity_recognition_has_been__.tex b/Human_Activity_recognition_has_been__.tex  index 0e42c83..3cd0f46 100644  --- a/Human_Activity_recognition_has_been__.tex  +++ b/Human_Activity_recognition_has_been__.tex 
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Human Activity recognition has been a critical range of Computer vision research subsequent to the 1980s. The previous decade has seen a fast advancement of 3D data acquisition techniques \cite{aggarwal2014human}. Such techniques involve recent advances in 3d depth cameras and motion capture technologies mostly for video games control interfaces that have brought motion capture into high extent \cite{regazzoni2014rgb}. In the work of \citet{zhang2012microsoft}, he stated that the Kinect sensor incorporates several advanced sensing hardware suitable for a wide range of applications that may vary from entertainment domain (e.g., video games, virtual characters in movies) to the Bio-mechanical and biomedical domain (e.g., gait analysis or orthopedic rehabilitation) and to a huge number of industrial sectors \cite{regazzoni2014rgb}. Most notably, it contains a depth sensor, a color camera, and a four-microphone array that provide full-body 3D motion capture, facial recognition, and voice recognition capabilities. capabilities \cite{smisek20133d}.  The depth sensor portion of the Kinect consists of the IR projector combined with the IR camera, which is a monochrome complementary metal oxide semiconductor (CMOS) sensor an a depth sensing technology based on Structured light principle.