In addition, further information was obtained about the evolution of the

relative velocity between the two phases.

V -

relative velocity of the fluid passing through the blade, m [s.sup.-1]; and,

A solution is given by the Karnopp (1985) model which considers that the stick occurs when the

relative velocity is 'small enough'; this condition is formulated as [??] < [eta] (instead of [??] = 0), where [eta] should be much smaller than the average speed values of the system elements.

The servicer can arrive at the DP while satisfying above control input,

relative velocity, and collision avoidance constraints in the aforementioned three cases.

The condition of closest approach that the

relative velocity and relative position are orthogonal (Figure 1) can be explained as follows: (i) if [mathematical expression not reproducible] at time t = [t.sub.*] then the vehicles would be moving towards each_other and would be closer at some later time [mathematical expression not reproducible] at time t = [t.sub.*] then the vehicles would be moving away from each other and would have been closer for some earlier time t < [t.sub.*].

Xin, "

Relative velocity difference model for the car-following theory," Nonlinear Dynamics, vol.

Keywords: Clustering, VANETs, Cluster Head, Cluster Member,

Relative velocity.

However, testing confirmed there was pressure development due to the

relative velocity between the surfaces--but it is a daunting task to mathematically quantify.

The Near Earth Object Program at NASA has a (http://neo.jpl.nasa.gov/ca/) chart that reveals the object names, approach date, distance, estimated diameter and

relative velocity of any potential passing objects.