Structured peer-to-peer overlays provide a natural infrastructure for resilient routing via efficient fault detection and precomputation of backup paths. These overlays can respond to faults in a few hundred milliseconds by rapidly shifting between alternate routes. In this paper, we present two adaptive mechanisms for structured overlays and illustrate their operation in the context of Tapestr...

would like to take this opportunity to thank all the people that supported me during this time personally and professionally. First of all, I would like thank Prof. Jochen Schiller who has been my primary adviser over the past three years. Without his support and inspiration as well as the confidence and freedom that he has given me to pursue my ideas, this work would never have been possible. ...

Most hash-based structured peer-to-peer (HS-P2P) architectures proposed previously focus on stationary peer nodes. When peers move to new locations in the network, these schemes become cumbersome and inefficient in delivering messages. This paper proposes a mobile HS-P2P architecture, called Bristle, which allows nodes to move freely. A node can disseminate its location information through the ...

Motivation and Related Work ‰Vulnerability of the overlay networks: Because of openness to participating in message forwarding and a lack of facilities ensuring the forwarding integrity, adversaries can easily disrupt the normal lookup message forwarding. ‰Severe damage caused by forwarding attacks: Even a small percentage of faulty nodes that inject forwarding faults can seriously degrade the ...

There are many common characteristics between Peer-toPeer (P2P) overlay networks and Mobile Ad-hoc Networks (MANET). Self-organization, decentralization, dynamicity and changing topology are the most shared features. Furthermore, when used together, the two approaches complement each other. P2P overlays provide data storage/retrieval functionality, and their routing information can complement t...

QUESTION What are the views and perceptions of people with chronic obstructive pulmonary disease (COPD) regarding maintaining an active lifestyle following a course of pulmonary rehabilitation? DESIGN Qualitative study of two focus groups using a grounded theory approach. PARTICIPANTS Sixteen people with COPD who had completed a course of pulmonary rehabilitation. RESULTS Data from focus ...

OBJECTIVE We examined the links of social relational (family environment and peer victimization) and neuroendocrinological (HPA axis dysregulation) risk factors to children's emotional symptoms. We placed special emphasis on the joint effects of these risk factors with respect to the emergence and course of the emotional symptoms. METHODS One hundred and sixty-six children were interviewed (B...

The structured peer-to-peer system, which is based on the distributed hash table, offers an administration-free and fault-tolerant application-level overlay network. However, a randomly structured overlay can not reflect the heterogeneity of a peer-to-peer system. In this paper, we propose a two-phase approach to exploit the heterogeneity in structured peer-to-peer systems. First, by exploiting...

We compare structured and unstructured overlays and derive a hybrid overlay that can outperform both. Unstructured overlays build a random graph and use flooding or random walks on that graph to discover data stored by overlay nodes. Structured overlays assign keys to data items and build a graph that maps each key to the node that stores the corresponding data. Unstructured overlays are widely...

In this paper, we introduce the concept of a structured peer-to-peer grid and present our contribution to this new world by means of DERMI, a wide-area decentralized object middleware. In addition, we focus on the design and implementation of a load balancing facility by using the functionalities provided by this middleware. We present two different approaches to achieve load balancing in our s...