  The characterization of finite-time thermodynamic processes is of crucial
importance for extending equilibrium thermodynamics to nonequilibrium
thermodynamics. The central issue is to quantify responses of thermodynamic
variables and irreversible dissipation associated with non-quasistatic changes
of thermodynamic forces applied to the system. In this study, we derive a
simple formula that incorporates the non-quasistatic response coefficients with
Onsager's kinetic coefficients, where the Onsager coefficients characterize the
relaxation dynamics of fluctuation of extensive thermodynamic variables of
semi-macroscopic systems. Moreover, the thermodynamic length and the dissipated
availability that quantifies the efficiency of irreversible thermodynamic
processes are formulated in terms of the derived non-quasistatic response
coefficients. The present results are demonstrated by using an ideal gas model.
The present results are, in principle, verifiable through experiments and are
thus expected to provide a guiding principle for the nonequilibrium control of
macroscopic thermodynamic systems.
