Sharif Digital Repository

Study of real networks has become an important research task. Real networks appear in different domains such as social networks and biological networks. It is also possible to extract various networks from the set of scientific collaborations of published papers. In this project we investigate the analysis of citation network and co-authorship networks of scientific papers in order to find out a new method in citation recommendation of scientific papers. Presented method have some superior properties over existing citation recommendation systems like combining different fields for suggesting most relevant papers to user, in response of user’s input keywords. For presenting this method we... 

Peer-to-Peer networks are invented to enable participants (peers) to share their resources and find and use the shared resources of the others. So the main issue is the mechanism of finding granted resources of the other peers. In Peer-to-Peer networks, there is no central server to index shared resources of the peers. So peers should collaborate to provide a fully distributed mechanism for searching resources. Considering the huge size of peer-to-peer systems, it is apparent that efficiency of the search mechanism is very critical. In this thesis, to have efficient seach in Peer-to-Peer networks, we propose two approaches. Then based on these approaches, we propose the third approach to... 

As cloud computing becomes a ubiquitous technology, data outsourcing, which means delegating storage and retrieval of the data to an extraneous service provider, becomes more popular. One of the main issues in data outsourcing is preserving data confidentiality and privacy. A common solution to this problem is encrypting the data before outsourcing, but this approach prevents the service provider from doing computations on the data. A trivial solution is to transfer all of the data to the client-side and decrypt it before doing the computations, but this solution imposes a large overhead on the client-side and contradicts the philosophy of outsourcing. Till now, so many encryption schemes... 

This thesis addresses the topic of cooperative search by a group of unmanned aerial vehicles (UAVs) in a bounded region, while encountering obstacles and searching for moving targets. A review of relevant research on cooperative search for finding one or multiple targets is presented. Then, a general description of the logic of cooperative search, which is based on optimal routing by minimizing a cost function, is explained. In this context, three maps called the uncertainty map, target presence probability map, and target map are introduced. Two phases of search and tracking are defined for the UAVs, and the criteria for achieving each phase are presented. In the search phase, each UAV...