A schema-based P2P network to enable publish-subscribe for multimedia content in open hypermedia systems

Open Hypermedia Systems (OHS) aim to provide efficient dissemination, adaptation and integration of hyperlinked multimedia resources. Content available in Peer-to-Peer (P2P) networks could add significant value to OHS provided that challenges for efficient discovery and prompt delivery of rich and up-to-date content are successfully addressed. This paper proposes an architecture that enables the operation of OHS over a P2P overlay network of OHS servers based on semantic annotation of (a) peer OHS servers and of (b) multimedia resources that can be obtained through the link services of the OHS. The architecture provides efficient resource discovery. Semantic query-based subscriptions over this P2P network can enable access to up-to-date content, while caching at certain peers enables prompt delivery of multimedia content. Advanced query resolution techniques are employed to match different parts of subscription queries (subqueries). These subscriptions can be shared among different interested peers, thus increasing the efficiency of multimedia content dissemination

Federated and autonomic management of multimedia services

Over the years, the Internet has significantly evolved in size and complexity. Additionally, the modern multimedia services it offers have considerably more stringent Quality of Service (QoS) requirements than traditional static services. These factors contribute to the ever-increasing complexity and cost to manage the Internet and its services. In the dissertation, a novel network management architecture is proposed to overcome these problems. It supports QoS-guarantees of multimedia services across the Internet, by setting up end-to-end network federations. A network federation is defined as a persistent cross-organizational agreement that enables the cooperating networks to share capabilities. Additionally, the architecture incorporates aspects from autonomic network management to tackle the ever-growing management complexity of modern communications networks. Specifically, a hierarchical approach is presented, which guarantees scalable collaboration of huge amounts of self-governing autonomic management components

Performance Optimization for Distributed Database Based on Cache Investment

As technology plays important role in every aspect of life especially in the industrial field, a vast amount of data is generated for controlling and monitoring tools and to help in system development. That results in an increased size of data, which affects the speed and performance of applications/programs. Here a design strategy is proposed to show how to improve both the speed and performance of computer applications by improving the performance of database queries. Key factors that determine computer performance (speed and performance of the processor) are the processor speed, the size of RAM, and the cache memory strategy for the processor. In this paper, we are introducing a solution that is proven to be a tool to increase the performance of queries. It will help to enhance the performance of database queries responsiveness irrespective of the database size. The proposed policy is built-up on the caching concepts i.e. cache investment. Cache investment is a method to combine query optimization and data placement. This work on the concept of investment looks beyond the performance of a single query and helps in achieving a better hit ratio in a long term for large database systems. This paper, discuss and explain the design, architecture and working of the proposed policy. The results show how this proposed policy helps in improving the performance of the database, especially relevant for today’s “big data” environment

Adaptive Replicated Web Documents.

Caching and replication techniques can improve latency of the Web, while reducing network traffic and balancing load among servers. However, no single strategy is optimal for replicating all documents. Depending on its access pattern, each document should use the policy that suits it best. This paper presents an architecture for adaptive replicated documents. Each adaptive document monitors its access pattern, and uses it to determine which strategy it should follow. When a change is detected in its access pattern, it re-evaluates its strategy to adapt to the new conditions. Adaptation comes at an acceptable cost considering to the benefits of per-document replication strategies. vrije Universiteit Faculty of Mathematics and Computer Science 1 Introduction Most Web users suffer from slow document transfers. The reasons for such high latencies include distance between the user and the document, and load of the intermediate network. One common solution is to maintain copies of ..

Network layer solutions for a content-centric internet

Nowadays most people exploit the Internet to get contents such as web pages, music or video files. These users only value “what” they download and are not interested about “where” content is actually stored. The IP layer does the opposite and cares about the “where” and not about the “what”. This contrast between the actual usage of the Internet and the service offered by the IP layer is deemed to be the source of several problems concerning usability, performance, security and mobility issues. To overcome this contrast, research on the Future Internet is exploring novel so-called content-centric architectures, where the network layer directly provides users with contents, instead of providing communication channels between hosts. In this paper, we identify the main functionalities of a content-centric network (CONET), we discuss pros and cons of literature proposals for an innovative, content-centric network layer and we draw our conclusions, stating some general requirements that, in our opinion, a CONET should satisfy