改进智能算法的认知无线Mesh网络优化频谱分配算法

随着网络资源日益紧张,认知无线Mesh网络中的频谱优化分配问题的研究主要集中在总带宽的最大化和占用频谱数的最小化。文中考虑到杂草算法的多样性以及容易实现和编码快捷等特点,提出一种基于改进入侵杂草优化算法(IWO)的频谱优化分配方法(IIOW)。通过对扩散条件中调和指数的优化,使得扩散更加均匀准确,大大加快收敛速度,同时优化了适应度函数的曲线。仿真结果表明:基于改进IWO的优化算法能在最大化总带宽与最小化信道占用数的情况下,获得较为理想的适应度函数曲线,同时加快收敛速度。     

Enantioselective C2-Alkylation of Indoles through a Redox-Relay Heck Reaction of 2-Indole Triflates

A palladium-catalyzed enantioselective redox-relay Heck reaction of 2-indole triflates and disubstituted alkenes is reported. This process combines readily available indole triflates with a variety of alkenes to afford a range of indole derivatives bearing a stereocenter adjacent to C2. Enantioselectivity is achieved through use of a simple pyridine-oxazoline ligand. Tuning the electronics of the indole, through judicious choice of N-protecting group, is required to ensure selective β-hydride elimination away from the indole core. Utility of this method is highlighted in a modular formal synthesis of an S1P₁ agonist precursor developed by Merck.     

n人可信策略博弈

本文研究模糊支付n人策略博弈,由于支付信息的不完全性,模糊支付可视为模糊变量。基于可信性理论,在不同的决策环境中引入模糊排序方法表征支付者行为。因此,本文定义四种可信均衡,等价于纳什均衡。其次证明了可信均衡存在性定理。除此之外,在现实策略博弈中用算例说明四种可信均衡的现实意义。最后讨论四种可信均衡之间可能存在的关系。     

A very mild and selective method for O-benzoylation of hydroxamic acids

Selective O-benzoylation of hydroxamic acids is achieved by the treatment of BPO and DABCO. Aliphatic alcohols are not reactive under these conditions. Various radical or oxidation sensitive functional groups are compatible with this protocol, and no anhydrous reagents or solvents are required for the high yields of the benzoylations.