Paper Title
Testing the Limit Cycle Behavior in Homothermal Maintenance of Skunk Cabbage

Abstract
The wild plant called Skunk Cabbage has a heating organ and heats itself at the end of winter, to raise seeds effectively. The body temperature is well controlled so that it is retained almost constant at around 22~24[°C] for several days, even when the ambient temperature falls below freezing. The temperature control mechanism is considered to have a linear equilibrium phase and nonlinear nonequilibrium phase, according to the displacements of the body temperature from a target temperature called central temperature. In our previous study, we have shown that linear behavior is well modeled by certain mixed Poisson distribution, which considers the conflicts of actions of increasing or decreasing temperatures. In this study, we consider modeling the nonlinear behavior part which is report here applicability of so-called Van der Pol equation as a possible candidate model. As well as we did attempt to determine whether the limit cycle behavior exists. Keywords - Nonlinear Nonequilibrium State, Limit Cycle Phenomena, Van der Pol Equation, Least-Squares Fitting, Chi- Square Goodness of Fit Test.