content discovery is one of the fundamental issues that determines the architecture and performance of content distribution networks based on peer-to-peer (p2p) networks. to administrate the costs and discoveries, peers of a p2p network communicate with each other by one or more overlay layers. the condition of node’s relations in overlay networks, have a great impact in efficiency of networks....

‎The first variable Zagreb index of graph $G$ is defined as‎ ‎begin{eqnarray*}‎ ‎M_{1,lambda}(G)=sum_{vin V(G)}d(v)^{2lambda}‎, ‎end{eqnarray*}‎ ‎where $lambda$ is a real number and $d(v)$ is the degree of‎ ‎vertex $v$‎. ‎In this paper‎, ‎some upper and lower bounds for the distribution function and expected value of this index in random increasing trees (rec...

The demands of Internet applications have grown significantly in terms of required resources and types of services. Overlay networks have emerged to accommodate such applications. The performance of an overlay network is, however, highly dependent on its topology; keeping logical links in an overlay network from interfering with each other is crucial in achieving high throughput. In this thesis...

The World Wide Web is growing at such a pace that even the biggest centralized search engines are able to index only a small part of the available documents on the Internet. The decentralized structure, together with the features of self-organization and fault-tolerance, makes peerto-peer networking an effective information-sharing model; however, content searching still remains a serious chall...

DHT systems are structured overlay networks capable of using P2P resources as a scalable platform for very large data storage applications. However, their efficiency expects a level of uniformity in the association of data to index keys that is often not present in inverted indexes. Index data tends to follow nonuniform distributions, often power law distributions, creating intense local storag...

We determine analytic expressions for the performance of some low-complexity combined source-channel coding systems. The main tool used is the Hadamard transform. In particular, we obtain formulas for the average distortion of binary lattice vector quantization with affine index assignments, linear block channel coding, and a binary-symmetric channel. The distortion formulas are specialized to ...

In the context of ubiquitous and pervasive computing, publish/subscribe middleware is gaining momentum due to its loosely coupled communication scheme. In this paper we present Q, a publish/subscribe service conceived to operate in the context of mobile ad hoc networks. With Q, the overlay network that routes events from publishers to subscribers dynamically adapts itself to the changing topolo...