A New SEN Minus: Design and Reliability Measures

Multistage interconnection networks (MIN) are becoming attractive choice as they provide fast and efficient communication at reasonable cost, for multiprocessing systems. Shuffle exchange network (SEN) are specific class of MIN characterized as lowest cost unipath MIN. Several developments have made SEN MIN fault tolerant with redundant paths by increasing the number or size of switching elements (SE). However, recently [Formula: see text] has been advanced by reducing the number of stages, but has serious limitation namely: (i) partial connectivity of each source–destination pair, (ii) unique path. A new method has been proposed in this paper to develop a new topology of MIN with one stage less than the basic unipath MIN of same class with multiple and disjoint path facility that mitigates the shortcomings of the above network and is truly [Formula: see text] MIN. Due to less number of stages used in the proposed network communication delays are also reduced as the path length is reduced. Parametric performances such as Terminal, Broadcast and Network Reliabilities, MTTF, Bandwidth have been computed for different network sizes and demonstrated that it not only outperforms other SEN variants, but has improved features of fault tolerance all because of disjoint minimal path set. Further the comments generated previously in literature about better reliability performance of [Formula: see text] than other two networks [Formula: see text] have been refuted and have demonstrated that [Formula: see text]2 network has better performance than other two for larger network size. Also it can be concluded that the performance of proposed [Formula: see text] is best among all these networks.

Partial connectivity increases cultural accumulation within groups

Complex technologies used in most human societies are beyond the inventive capacities of individuals. Instead, they result from a cumulative process in which innovations are gradually added to existing cultural traits across many generations. Recent work suggests that a population’s ability to develop complex technologies is positively affected by its size and connectedness. Here, we present a simple computer-based experiment that compares the accumulation of innovations by fully and partially connected groups of the same size in a complex fitness landscape. We find that the propensity to learn from successful individuals drastically reduces cultural diversity within fully connected groups. In comparison, partially connected groups produce more diverse solutions, and this diversity allows them to develop complex solutions that are never produced in fully connected groups. These results suggest that explanations of ancestral patterns of cultural complexity may need to consider levels of population fragmentation and interaction patterns between partially isolated groups.