  We model measuring processes of a single spin-1/2 object and of a pair of
spin-1/2 objects in the EPR-Bohm state by systems of differential equations.
Our model is a local model with hidden-variables of the EPR-Bohm
Gedankenexperiment. Although there is no dynamical interaction between a pair
of spin-1/2 objects, the model can reproduce approximately the
quantum-mechanical correlations by the coincidence counting. Hence the Bell
inequality is violated. This result supports the idea that the coincidence
counting is the source of the non-locality in the EPR-Bohm Gedankenexperiment.
