The Chinese are simply blasting roads into unstable hillsides with virtually no attention paid to road location, construction practices or erosion control.
However, since these approaches take no account of complexity control and have no guarantee of global minimum, they often suffer from unstable performance.
但是由于这些方法不考虑复杂度的控制以及不能保证全局最小值，所以它们的性能不稳定。
3
Ball and beam system is a nonlinear and unstable system, which is designed for experiments of basic control curriculum such as feedback control.