def METHOD_NAME(self):
    """
    @brief Determine boundary nodes in the 1D structure mesh.
    @return isBdNode : np.array, dtype=np.bool_
        An array of booleans where True indicates a boundary node.
    """
    isBdNode = np.zeros(self.NN, dtype=np.bool_)
    isBdNode[0] = True
    isBdNode[-1] = True
    return isBdNode 