where [??] is the

unit vector in the direction of the positive x-axis and [??] is the

unit vector in the direction of the positive y-axis.

as a unit of search,'

Unit Vector' refers to the size of the vector to consider when comparing a time.

b and c are the direction cosines of the

unit vector [??] = [a, b, c] of the normal to the plane (1), which coincides with the vector [??].

The control scheme for the SEHAPF using FSMPWM and

unit vector is depicted in Section 3.

The

unit vector [[??].sub.3] is aligned with the Earth axis of rotation and is positive northward, whereas [[??].sub.1] is aligned with the vernal axis, which corresponds to the intersection of the Earth equatorial plane with the ecliptic plane.

Denoting its angle 0 and the

unit vector along its axis n, one may express the associated quaternion as

Similarly, we set [e.sub.2] to an arbitrary

unit vector with an orthogonal projection on the subspace < [e.sub.-1], [e.sub.0], [e.sub.1] > lying on the line with directing vector [r.sub.1] and the angle between this vector and [r.sub.1] equal [[alpha].sub.1], and select the coefficient [c.sub.2] in such a way that for [r.sub.2] = [r.sub.1]-[c.sub.2][e.sub.2] scalar products ([r.sub.2], -[e.sub.2]), ([r.sub.2], -[e.sub.1]), ([r.sub.2], [e.sub.0]), ([r.sub.2], [e.sub.-1]) are equal or, equivalently, angles between [r.sub.2] and the vectors [e.sub.-1], [e.sub.0], -[e.sub.1], -[e.sub.2] are equal.

[[??].sub.0] is a

unit vector for [y.sub.0] axis, [[??].sub.0] a

unit vector for [z.sub.0], axis, [[??].sub.c] a

unit vector for [y.sub.c] axis and [[??].sub.c] a

unit vector for [Z.sub.c] axis.

Using the mass-metric, if N denotes the

unit vector field normal to [T.sub.x]S in [T.sub.x][F.sub.n](E), the projection of [[nabla].sup.S.sub.v]u of any vector field u on [T.sub.x]S is

The gravity force is given by [[??].sub.g] = - m.g[??] where [??] is a

unit vector along the global fixed axis z in the inertial reference frame (x, y, z).

Both these energy phenomena are described from the same methodological positions within the framework of a general mathematical model in which an essential role is played by the ZS

unit vector (a vector with a unit norm)

propagates along the direction given by the

unit vector N.