The increased using of the Internet and its accelerated growth leads to reduced network bandwidth and the capacity of servers; therefore, the quality of Internet services is unacceptable for users while the efficient and effective delivery of content on the web has an important role to play in improving performance. Content distribution networks were introduced to address this issue. Replicating and caching are the two main techniques to find the optimal substitute server for replicating the content in these networks. Most of the past research has focused on these two methods separately. In this paper, first the surrogate server’s storage divides into two regions for dynamic and static contents. Then with combining the cache and replication techniques, a heuristic hybrid method based on the greedy algorithm is proposed to add contents in dynamic or static cache regions. In this technique, any possible content is evaluated in each replication, and the best ones are selected and replicated according to the conditions. At the end the proposed approach evaluated in CDNsim environment and the results shown that the algorithm reduced average response time and maximize hit ratio. تفاصيل المقالة

Networks on chip (NoCs) are an idea for implementing multiprocessor systems that have been able to handle the communication between processing cores, inspired by computer networks. Efficient nonstop routing is one of the most significant applications of NOC. In this study, the performance improvement of Networks on Chip (NoC) is investigated by introducing an optimal selection strategy. One of the most important features of NoC is an efficient and continuous routing. The effect of any routing algorithm depends on the chosen strategy. Accordingly, in the proposed approach, packet traffic is first examined using an analyzer and then based on the number of steps, it is determined whether packets are local or not. Finally, packets are sent through the best output channel using the Regional Congestion Awareness (RCA) selection strategy for local traffic and Neighbors-on-Path (NoP) for non-local traffic. Using a simulation, it is shown that the proposed approach significantly increased the performance. Experiments show that in compared to BufferLevel and Random strategies, this method remarkably reduces the average delay and energy consumption. تفاصيل المقالة