When emerging technologies such as Search Engine Marketing (SEM) face tasks that require human level intelligence, it is inevitable to use the knowledge repositories to endow the machine with the breadth of knowledge available to humans. Keyword suggestion for search engine advertising is an important problem for sponsored search and SEM that requires a goldmine repository of knowledge. A recent strategy in this area is bidding on non-obvious yet relevant keywords, which are economically more viable. In this paper, we exploited a modified relevance-based language model for keyword suggestion problem using Wikipedia as our knowledge base. Huge amounts of clean information in Wikipedia allowed us to uncover important relations between concepts and suggest excessive low volume, inexpensive keywords. Also, we will show the viability of our approach by comparing its results to recent proposed systems. Compared to previous researches, our proposed approach have many advantages, namely, being language independent, being well-grounded, containing expert keywords and being more computationally efficient. تفاصيل المقالة

The popularity of video-on-demand (VoD) streaming has grown dramatically over the World Wide Web. Most users in VoD P2P networks have to wait a long time in order to access their requesting videos. Therefore, reducing waiting time to access videos is the main challenge for VoD P2P networks. In this paper, we propose a novel algorithm for caching video based on peers' priority and video's popularity distribution. The proposed mechanism has been evaluated on two different kinds of topology, Erdos-Renyi Model and Barabasi-Albert Model. It's necessary to mention that scale-free topologies are much more similar to P2P networks like Internet; so it’s closer to reality much more. However, decreasing waiting time is more tangible in them too. The results demonstrate that how our caching mechanism can reduce delay, improve bandwidth consumption, and decrease transport costs. Finally we came to the conclusion that increasing networks' size and videos' chunks has led to decrease much more delay by using proposed algorithm. تفاصيل المقالة