Spatio-temporal Analysis in large scale Internet environment

A synthetic resin bobbin comprising at least one contractable wall constituting a desired portion of peripheral side wall of a tubular synthetic resin bobbin main body. The contractable wall is composed of a plurality of connecting members bent in a V-shaped or inverted V-shaped form and arranged vertically along the vertical wall of the main body. When the bobbin is subjected to pressure due to the shrinkage of yarn wound thereon, the connecting members are elastically contracted at their bent portions to contract the contractable wall.