This paper presents a new two-stage multi-swarm particle swarm optimizer (TMPSO). which employs the multi-swarm method and takes two-stage different search strategies in the whole iteration process. This new optimizer includes two versions: unconstrained TMPSO (uTMPSO) and constrained TMPSO (cTMPSO) for unconstrained and constrained global optimizations respectively. For the uTMPSO ve... https://atlanticknifers.shop/product-category/spear/