Since inception, DNS has used a TTL-based replication scheme that allows the source (i.e., an authoritative domain server) to control the frequency of record eviction from client caches. Existing studies of DNS predominantly focus on reducing query latency and source bandwidth, both of which are optimized by increasing the cache hit rate. However, this causes less-frequent contacts with the sou...

Classic replication protocols running on traditional cluster-based databases are currently unable to meet the ever-growing scalability demands of many modern software applications. Recent cloud-based storage repositories overcome such limitations by fostering availability and scalability over data consistency and transactional support. However, many applications that cannot resign from their tr...

This work studies the interaction of Web proxy cache coherency and replacement policies using trace-driven simulations. We specifically examine the relative importance of each type of policy in affecting the overall costs, the potential of incorporating coherency issues in cache replacement and the inclusion of additional factors such as frequency of resource use in replacement and coherency po...

Almost over the last 20 years grid technology has been developed to exploit unutilized computing capacity around the world. The two major application areas are solving computing intensive problems having less data (computational grid) or operating on large volumes of data (data grid). From a database perspective it is advisable to replicate data sets at different nodes in the grid before execut...

Existing reliable transport protocols for periodic information dissemination ignore application semantics while attempting to be 100% reliable. \Application Level Framing" (ALF) suggests that taking application semantics into account when designing transport protocols can result in performance that is highly optimized for the network. We apply this principle in designing a policy-based TUNAble ...

The physical training undertaken by athletes is one of a set of lifestyle or behavioural factors that can influence immune function, health and ultimately exercise performance. Others factors including potential exposure to pathogens, health status, lifestyle behaviours, sleep and recovery, nutrition and psychosocial issues, need to be considered alongside the physical demands of an athlete's t...

The research community is addressing a number of issues in response to increased reliance of organisations on data warehousing. Most work addresses individual aspects related to incremental view maintenance, propagation algorithms, consistency requirements, performance of OLAP queries etc. There remains a need to consolidate relevant results into a cohesive framework for data warehouse maintena...

Dynamic overlay routing has been proposed as a way to enhance the reliability and performance of IP networks. The major premise is that overlay routing can bypass congestion, transient outages, or suboptimal paths, by forwarding traffic through one or more intermediate overlay nodes. In this paper, we perform an extensive simulation study to investigate the performance of dynamic overlay routin...

Description is given of methods that can evaluate the main functional elements of the immune system. Acute responses to exercise depend on the intensity and duration of the required activity relative to the individual's fitness level. Moderate endurance exercise causes either no change or an enhancement of such indices as total leucocyte count, granulocyte, monocyte, lymphocyte and natural kill...

We consider the problem of increasing the availability of shared data in peer-to-peer (P2P) systems so that users can access any content, regardless of the current subset of online peers. In particular, we seek to conservatively estimate the amount of excess storage required to achieve a practical availability of 99.9% by studying a decentralized algorithm that only depends on a modest amount o...