  In measurement-based quantum computation (MBQC), elementary quantum
operations can be more parallelized than the quantum circuit model by employing
a larger Hilbert space of graph states used as the resource. Thus MBQC can be
regarded as a method of quantum computation where the temporal resource
described by the depth of quantum operations can be reduced compared to the
quantum circuit model by using the extra spatial resource described by graph
states. To analyze the trade-off relationship of the spatial and temporal
resources, we consider a method to obtain quantum circuit decompositions of
general unitary transformations represented by MBQC on graph states with a
certain underlying geometry called generalized flow. We present a method to
translate any MBQC with generalized flow into quantum circuits without extra
spatial resource. We also show an explicit way to unravel acausal gates that
appear in the quantum circuit decomposition derived by a translation method
presented in [V. Danos and E. Kashefi, Phys. Rev. A {\bf 74}, 052310 (2006)]
and that represent an effect of the reduction of the temporal resource in MBQC.
Finally, by considering a way to deterministically simulate these acausal
gates, we investigate a general framework to analyze the trade-off between the
spacial and temporal resources for quantum computation.
