This pattern applied in all three age groups in all tasks, except for multi-directional pointing with a larger target width among the older group.
This study assessed the use of an immersive virtual reality (VR), a mouse and a touchscreen for one-directional pointing, multi-directional pointing, and dragging-and-dropping tasks involving targets of smaller and larger widths by young (n = 18; 18 30 years), middle-aged (n = 18; 40 55 years) and older adults (n = 18; 65 75 years).
Since input data for each reference object is a set of directional point clouds (acquired from different directions), there is no need to perform any preliminary segmentation or to use iterative closest point (ICP-type) [25] algorithms, to obtain full 3D reference object, like in [4].
A directional antenna can form a directional beam pointing at the receiver by concentrating its transmit power into that direction.
A range image is a projection of the single, directional point cloud (which is point cloud acquired from single direction—so-called 2.5D data) onto a plane, therefore uniqueness cannot be maintained for full 3D objects (formed from numerous directional clouds of points integrated in a single model).
A directional antenna could form a directional beam pointing to the receiver, and only nodes in the main lobe beam region can receive signals well.
A LOS PtMP backhaul solution where the PoP is equipped with directional antennas pointing in different directions is well suited for higher frequency bands due to the larger antenna gains, thus allowing to exploit larger bandwidths and therefore capacity.
In this case, the PoP acts as a unique data sink and can be equipped with either an omnidirectional antenna or a number of directional antennas pointing in different directions, e.g., antenna arrays with static beams, large scale antenna systems (LSAS) [7].
In the next step, normal vectors for the directional point cloud data are calculated.
Unfortunately, they are not suitable for data in the form of single directional point clouds.
Each reference object is presented as a set of directional point clouds acquired from various points of view.
