  We use a driven Monte Carlo dynamics in the phase representation to determine
the linear resistivity and current-voltage scaling of a two-dimensional
Josephson-junction array at an irrational flux quantum per plaquette. The
results are consistent with a phase-coherence transition scenario where the
critical temperature vanishes. The linear resistivity is nonzero at any finite
temperatures but nonlinear behavior sets in at a temperature-dependent
crossover current determined by the thermal critical exponent. From a dynamic
scaling analysis we determine this critical exponent and the thermally
activated behavior of the linear resistivity. The results are in agreement with
earlier calculations using the resistively shunted-junction model for the
dynamics of the array. The linear resistivity behavior is consistent with some
experimental results on arrays of superconducting grains but not on wire
networks, which we argue have been obtained in a current regime above the
crossover current.
