Here S (the "source") represents the bow of the ship which is moving from left to right with uniform speed U, and the lines labeled C, C′, C″, etc., represent a set of parallel wave crests which are also moving from left to right.
In the theory, two-dimensional motion with the wave crests parallel to the submerged wavy plate and the linearized irrotational flow are assumed.
"Width" refers to the extent of the DB parallel to the crest.
The tape was applied above the iliac crest, parallel to the ground, with the individual standing with the abdomen relaxed, arms along the body, and feet together.
WC was measured in the standing relaxed position, during expiration, at the midline between the lower costal margins and the iliac crest parallel to the floor.
Starting at 5 years, waist circumference was measured in triplicate by placing a measuring tape around the abdomen at the level of the iliac crest, parallel to the floor and measures were averaged.
A single longitudinal DB (long crest parallel to flow direction; Cooke et al. 1993) has been found at the edge of the dense pyroclastic flow path behind a standing tree (1 m diameter; Fig. 8d).
b) Waist circumference: the mean of three measurements, using a flexible measuring tape at waist level (at the midpoint between the last rib and the iliac crest), parallel to the floor, and measuring after inspiration.
Starting at age 5 years, we also measured waist circumference to the nearest 0.1 cm by placing a measuring tape around the abdomen at the level of the iliac crest, parallel to the floor.
The main shaft is aligned parallel to the wave crests and submerged at a fixed depth.
