Experimental Study of Mixed-Mode Oscillations in a Four-Segment Piecewise Linear Bonhoeffer-van der Pol Oscillator under Weak Periodic Perturbation -Successive and Nonsuccessive MMO-Incrementing Bifurcations- Tri Quoc TRUONGTadashi TSUBONEKuniyasu SHIMIZUNaohiko INABA