Methods, systems, and apparatus for determining similarity measures between vertical categories based on users’ online activities. In one embodiment, a first device receives a capability message over a communication link from a second device in a WiMAX network. Such torso shell section has vent holes formed therein to prevent water displacement within the fairing by air and is provided with buoyancy distributing weights to neutralize the effect of positive buoyancy during forward movement through seawater. The simulation includes solving equations governing the viscoelastic flow of the first fluid through the channel, including viscoelastic stress equations that include a normalized relaxation time greater than or equal to 5. An assessment is made whether modifications to the frames are needed, because of discontinuities in the model parameters at unit boundaries, or because of differences between the desired and selected unit features. Since the demodulation circuit and the dc power generating circuit are structurally independent of each other, interference between elements included in these circuits can be eliminated and simple designing is enabled.