正则有理Bezier曲线的等距曲线算法

通过利用改进的有理德卡斯特里奥算法求得正则有理ｎ次Ｂｅｚｉｅｒ曲线各点处的切矢,由此得到各点的单位法矢量,应用于求原始曲线的等距曲线,从而巧妙地解决了原始正则有理ｎ次Ｂｅｚｉｅｒ曲线上各点的单位法矢量难求的困难。该方法几何意义明显,算法简洁,实践效果比较好,最后本文给出了两个实例。     

Beyond the Unidades de Polícia Pacificadora: Countering Comando Vermelho’s Criminal Insurgency

Ten years ago, in 2008, the Brazilian Government adopted a strategy to regain control over the favelas in Rio de Janeiro – the Pacifying Police Units (UPP). In spite of initial favorable results, the main threat, namely the Red Command (CV), fought back and by 2014 the UPP strategy was badly frayed. In order to defeat this threat, it is necessary to reconceptualize CV as a criminal insurgency and to pinpoint and address the social and political factors that sustain it. This allows for a response inspired by the ‘shape-clear-hold-build’ counterinsurgency approach, which while cost-intensive is, in the long term, the most sustainable path to achieving security within the favelas and integrating these neglected areas within the broader city of Rio de Janeiro.