  Ubiquitous sensing is tightly coupled with activity recognition. This survey
reviews recent advances in Ubiquitous sensing and looks ahead on promising
future directions. In particular, Ubiquitous sensing crosses new barriers
giving us new ways to interact with the environment or to inspect our psyche.
Through sensing paradigms that parasitically utilise stimuli from the noise of
environmental, third-party pre-installed systems, sensing leaves the boundaries
of the personal domain. Compared to previous environmental sensing approaches,
these new systems mitigate high installation and placement cost by providing a
robustness towards process noise. On the other hand, sensing focuses inward and
attempts to capture mental activities such as cognitive load, fatigue or
emotion through advances in, for instance, eye-gaze sensing systems or
interpretation of body gesture or pose. This survey summarises these
developments and discusses current research questions and promising future
directions.
