<p>The World-Wide Web allows users to quickly and easily publish information in the form of web pages. Pages are linked to other pages already on the web using a hyperlink inserted into a web page by the page's author that contains the URL address of another existing web page. This model of web publishing, although simple and efficient, also has the effect that links between pages must be created manually and only to pages that are known to the author of the links. This can be a disadvantage if, for example, information in a particular field is incomplete and expanding rapidly over time, and where a page author cannot be expected to know which pages are the most appropriate to link to and when they become available.</p>
<p>In this paper, we look at a radically different model of web publishing in which the author of a web page does not specify links using URLs. Instead, the page author expresses an interest about the kind of content the page should link to and as new content comes online that matches that interest, links are inserted automatically into the original page to point to the new content. This leads to the possibility that a hyperlink from a particular location in a web page can lead to multiple destinations, something we call a multi-valued hyperlink.</p>
<p>We also describe a prototype implementation of our web architecture, based on the CHORD-based peer-to-peer overlay network, which uses publish/subscribe to communicate page author interests to other peers in order to create links between pages.</p>
<p>Searching social networks is determined by two factors: reputation and relevance. Reputation is the memory and summary of behavior from past transactions. Relevance is the probability that useful information can be obtained from a person. Search in social networks is performed by asking persons of high relevance and a good reputation or persons who are supposed to know somebody like that. We describe how these social aspects can be used in peer-to-peer networks in order to increase efficiency and scalability. Based on a social peer-to-peer network a knowledge management application with advantages over centralized approaches can be implemented.</p>
<p>A number of structured peer-to-peer (P2P) lookup protocols have been proposed recently. A P2P lookup protocol routes a lookup request to its target node in a P2P distributed system. Existing protocols achieve balanced routing traffic among nodes by assuming that lookup requests are evenly targeted at every node. However, when lookup requests concentrate on a few nodes simultaneously, these nodes become hot spots. Due to uneven routing patterns in existing protocols, hot spots cause unbalanced routing traffic which leads to routing bottlenecks. In this paper, we present a novel structured P2P lookup protocol called SCALLOP that delivers balanced routing and avoids routing bottlenecks at occurrences of hot spots. Among existing protocols, SCALLOP is the first one to accomplish this goal at the fundamental nature of a routing protocol. SCALLOP achieves balanced routing by uniquely constructing a balanced lookup tree for each node. The balanced tree evenly distributes routing traffic among sibling nodes and, therefore, avoids or reduces routing bottlenecks. In addition, as a load-balanced protocol, SCALLOP delivers asymptotically optimal lookup performance at the tradeoff between routing path and routing table size. We conducted a set of simulations to demonstrate the effectiveness of SCALLOP. The results show that, compared with a most-referenced and representative structured P2P lookup protocol and a graph-based extension of this protocol, SCALLOP significantly reduces routing bottlenecks while all three protocols deliver comparable lookup performance.</p>
<p>In this paper, we present a theoretical framework for design and analysis of distributed flocking algorithms. Two cases of flocking in free-space and presence of multiple obstacles are considered. We present three flocking algorithms: two for free-flocking and one for constrained flocking. A comprehensive analysis of the first two algorithms is provided. We demonstrate the first algorithm embodies all three rules of Reynolds. This is a formal approach to extraction of interaction rules that lead to the emergence of collective behavior. We show that the first algorithm generically leads to regular fragmentation, whereas the second and third algorithms both lead to flocking. A systematic method is provided for construction of cost functions (or collective potentials) for flocking. These collective potentials penalize deviation from a class of lattice-shape objects called alpha-lattices. We use a multi-species framework for construction of collective potentials that consist of flock-members, or alpha-agents, and virtual agents associated with alpha-agents called beta- and gamma-agents. We show that migration of flocks can be performed using a peer-to-peer network of agents, i.e., "flocks need no leaders." A "universal" definition of flocking for particle systems with similarities to Lyapunov stability is given. Several simulation results are provided that demonstrate performing 2-D and 3-D flocking, split/rejoin maneuver, and squeezing maneuver for hundreds of agents using the proposed algorithms.</p>
<item_title>Solving abduction by computing joint explanations: Logic programming formalization, applications to P2P data integration, and cmplexity results</item_title>
<p>An extension of abduction is investigated where explanations for bunches of observations may be jointly computed by sets of interacting agents. At one hand, agents are allowed to partially contribute to the reasoning task, so that joint explanations can be singled out even if each agent does not have enough knowledge for carrying out abduction on its own. At the other hand, agents maintain their autonomy in choosing explanations, each one being equipped with a weighting function reflecting its perception about the reliability of set of hypotheses. Given that different agents may have different and possibly contrasting preferences, some reasonable notions of agents' agreement are introduced, and their computational properties are thoroughly studied. As an example application of the framework discussed in the paper, it is shown how to handle data management issues in Peer-to-Peer systems and, specifically, how to provide a repair-based semantics to inconsistent ones.</p>
<p>This article presents an architecture to automatically create ad-hoc processes for complex value-added services and to execute them in a reliable way. The uniqueness of ad-hoc processes is to support users not only in standardized situations like traditional workflows do, but also in unique non-recurring situations. Based on user requirements, a service composition engine generates such ad-hoc processes, which integrate individual services in order to provide the desired functionality. Our infrastructure executes ad-hoc processes by transactional agents in a peer-to-peer style. The process execution is thereby performed under transactional guarantees. Moreover, the service composition engine is used to re-plan in the case of execution failures.</p>
<rp_address>Univ New S Wales, Sch Comp Sci & Engn, Sydney, NSW 2052, Australia</rp_address>
<rp_organization>Univ New S Wales</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Sch Comp Sci & Engn</rp_suborganization>
</rp_suborganizations>
<rp_city>Sydney</rp_city>
<rp_state>NSW</rp_state>
<rp_country>Australia</rp_country>
<rp_zips count="1">
<rp_zip location="AP">2052</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
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<rs_address>Univ New S Wales, Sch Comp Sci & Engn, Sydney, NSW 2052, Australia</rs_address>
<rs_organization>Univ New S Wales</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Sch Comp Sci & Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Sydney</rs_city>
<rs_state>NSW</rs_state>
<rs_country>Australia</rs_country>
<rs_zips count="1">
<rs_zip location="AP">2052</rs_zip>
</rs_zips>
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<abstract avail="Y" count="1">
<p>Performing business processes normally requires dynamic and casual collaborations among enterprises that are not centrally controlled. Enterprise application integration and Peer-to-Peer computing provide a solution to the business processes. Web service integration and agent-based middleware constitute the paradigms to implement enterprise application integration on Peer-to-Peer networks because of the loosely-coupled property of Web services and the autonomous, adaptive, and interactive properties of agents. Previous Web service integration researches focused on Web service integration based on client/server network architecture. However, along with the highly demands of Web service quality, Web services are not always provided on client/server networks. This research aims to construct an agent-based middleware for Web service dynamic integration on Peer-to-Peer networks to pursue the integration of optimal quality of Web services for enterprise application integration. The paper introduces the agent-based middleware including the formalization, Web service dynamic integration model, agent reasoning model, and the application.</p>
<p>Distributed Ascending Proxy Auction - A Cryptographic Approach. In recent years, auctions have become a very popular price discovery mechanism in the Internet. The common auction formats are typically centralized in nature. The peer-to-peer paradigm demands gearing up auctions for decentralized infrastructures. In this context, this paper proposes a distributed mechanism for ascending second-price auctions that relies on standard cryptographic algorithms. in essence, the auction protocol has the capability of preserving the privacy of the winning bidder's true valuation.</p>
<p>The auction protocol makes use of a high number of auctioneers divided into several groups. A bidder creates an encrypted chain of monotonously increasing bidding steps, where each bidding step can be decrypted by a different auctioneer group. This considerably reduces the attack and manipulation possibilities of malicious auctioneers. In addition, this secure approach does not require bidders to be online unless they are submitting their bid chain to the auctioneers.</p>
<p>In this paper, we describe the SomeWhere semantic peer-to-peer data management system that promotes a "small is beautiful" vision of the Semantic Web based on simple personalized ontologies (e.g., taxonomies of classes) but which are distributed at a large scale. In this vision of the Semantic Web, no user imposes to others his own ontology. Logical mappings between ontologies make possible the creation of a web of people in which personalized semantic marking up of data cohabits nicely with a collaborative exchange of data. In this view, the Web is a huge peer-to-peer data management system based on simple distributed ontologies and mappings.</p>
<rp_address>Univ Oregon, Eugene, OR 97402 USA</rp_address>
<rp_organization>Univ Oregon</rp_organization>
<rp_city>Eugene</rp_city>
<rp_state>OR</rp_state>
<rp_country>USA</rp_country>
<rp_zips count="1">
<rp_zip location="AP">97402</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
<research>
<rs_address>Univ Oregon, Eugene, OR 97402 USA</rs_address>
<rs_organization>Univ Oregon</rs_organization>
<rs_city>Eugene</rs_city>
<rs_state>OR</rs_state>
<rs_country>USA</rs_country>
<rs_zips count="1">
<rs_zip location="AP">97402</rs_zip>
</rs_zips>
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<abstract avail="Y" count="2">
<p>The recent success of Internet-based computing projects, coupled with rapid developments in peer-to-peer systems, has stimulated interest in the notion of harvesting idle cycles under a peer-to-peer model. The problem we address in this paper is the development of scheduling strategies to achieve faster turnaround time in an open peer-based desktop grid system. The challenges for this problem are two-fold: How does the scheduler quickly discover idle cycles in the absence of global information about host availability? And how can faster turnaround time be achieved within the opportunistic scheduling environment offered by volunteer hosts? We propose a novel peer-based scheduling method, Wave Scheduler, which allows peers to self organize into a timezone-aware overlay network using structured overlay network, The Wave Scheduler then exploits large blocks of idle night-time cycles by migrating jobs to hosts located in night-time zones around the globe, which are discovered by scalable resource discovery methods.</p>
<p>Simulation results show that the slowdown factors of all migration schemes are consistently lower than the slowdown factors of the nonmigration schemes. Compared to traditional migration strategies we tested, the Wave Scheduler performs best. However under heavy load conditions, there is contention for those night-time hosts. Therefore, we propose an adaptive migration strategy for Wave Scheduler to further improve performance.</p>
<p>To efficiently deliver streaming media, researchers have developed technical solutions that fall into three categories, each of which has its merits and limitations. Infrastructure-based CDNs with dedicated network bandwidths and hardware supports can provide high-quality streaming services, but at a high cost. Server-based proxies are cost-effective but not scalable due to the limited proxy capacity in storage and bandwidth, and its centralized control also brings a single point of failure. Client-based P2P networks are scalable, but do not guarantee high-quality streaming service due to the transient nature of peers. To address these limitations, we present a novel and efficient design of a scalable and reliable media proxy system assisted by P2P networks, called PROP. In the PROP system, the clients' machines in an intranet are self-organized into a structured P2P system to provide a large media storage and to actively participate in the streaming media delivery, where the proxy is also embedded as an important member to ensure the quality of streaming service. The coordination and collaboration in the system are efficiently conducted by our P2P management structure and replacement policies. Our system has the following merits: 1) It addresses both the scalability problem in centralized proxy systems and the unreliable service concern by only relying on the P2P sharing of clients. 2) The proposed content locating scheme can timely serve the demanded media data and fairly dispatch media streaming tasks in appropriate granularity across the system. 3) Based on the modeling and analysis, we propose global replacement policies for proxy and clients, which well balance the demand and supply of streaming data in the system, achieving a high utilization of peers' cache. We have comparatively evaluated our system through trace-driven simulations with synthetic workloads and with a real-life workload extracted from the media server logs in an enterprise network, which shows our design significantly improves the quality of media streaming and the system scalability.</p>
<p>Despite the leaps and bounds made by the P2P research field in the last few years, the benefit of this innovation has been constrained to a few areas; search and file-sharing and storage to name a few. In particular, this innovation has had little significant impact in the field of distributed computing.</p>
<p>There are several obstacles to be overcome in the development of any distributed computer, most notably: scalability, fault tolerance, security and load balancing. The difficulty of these is compounded in the dynamic, decentralized environment which characterizes the P2P arena. This paper presents a method of recovering from faults which exploits the distributed hash table functionality provided by modem overlay networks. Its effectiveness is evaluated experimentally using a proof of concept P2P distributed computer.</p>
<p>It is hoped that by providing a solution to one of the obstacles, global, decentralized, dependable distributed computers will be one step closer to reality.</p>
<p>With the increasingly developed technology of mobile devices and wireless networks, more and more users share resources by mobile devices via wireless networks. Compared to traditional C/S architecture, P2P network is more appropriate for mobile computing environment. However, all existing P2P protocols have not well considered the characteristics and constraints of mobile devices and wireless networks. In this paper, we will present a novel mobile P2P protocol, M-Chord, by adopting hierarchical structure and registering mechanism on the basis of Chord. The experimental results show that M-Chord system has high-efficiency and good robustness in mobile P2P network.</p>
<rp_address>Huazhong Univ Sci & Technol, Cluster & Grid Comp Lab, Wuhan 430074, Peoples R China</rp_address>
<rp_organization>Huazhong Univ Sci & Technol</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Cluster & Grid Comp Lab</rp_suborganization>
</rp_suborganizations>
<rp_city>Wuhan</rp_city>
<rp_country>Peoples R China</rp_country>
<rp_zips count="1">
<rp_zip location="AC">430074</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
<research>
<rs_address>Huazhong Univ Sci & Technol, Cluster & Grid Comp Lab, Wuhan 430074, Peoples R China</rs_address>
<rs_organization>Huazhong Univ Sci & Technol</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Cluster & Grid Comp Lab</rs_suborganization>
</rs_suborganizations>
<rs_city>Wuhan</rs_city>
<rs_country>Peoples R China</rs_country>
<rs_zips count="1">
<rs_zip location="AC">430074</rs_zip>
</rs_zips>
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<abstract avail="Y" count="1">
<p>A semantic Peer-to-Peer (P2P) scientific references sharing system, SemreX, is introduced in this paper. As a P2P application system based on JXTA, the implementation technologies of the P2P communication layer of SemreX are illustrated, including the software architecture and the classes in P2P communication layer. Some lessons about JXTA, from the system development practices and software testing, are also concluded, such as peer automatic discovery, program robustness and bug report.</p>
<p>Peer-to-Peer (P2P) networks have emerged as a prime research topic, partly due to the vast unexploited possibilities unrestricted distribution of the workload provides. The main hindrance for unrestricted exploitation of the P2P topology is, due to lack of security-related issues, the gullible attitude taken towards unknown agents. Therefore, the severity of the vulnerabilities caused by gullibility must be mended by other means, for example, by an effective incentive scheme encouraging agents to trustworthy behaviour. This paper presents an abstract model for incentive enhanced trust, to progressively assign the participating agents rights for accessing distributed resources, emphasising consistent behaviour. The model consists of a degrading formula, an illustrative incentive triangle and a best-effort distributed supervision model. Moreover, the same incentive model facilitates anticipation of future behaviour concerning any given agent founded on several distinct agents' opinion, suggesting that any knowledge concerning the counterpart is better than none.</p>
<p>This paper proposes a novel distributed routing system for integration between peer-to-peer (P2P) applications and mobile ad hoc networks (MANETs). This system takes advantage of the "zone" concept to reduce the multicast flooding. Significantly, the system investigates a mechanism to integrate key lookup in the application layer with routing in the link layer. The routing method provides a general-purpose technique that is not limited to any specific P2P applications. This paper presents the design of the routing system and sketches the layered architecture built according to the system functions.</p>
<rs_suborganization>Dept Comp Sci & Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Shanghai</rs_city>
<rs_country>Peoples R China</rs_country>
<rs_zips count="1">
<rs_zip location="AC">200030</rs_zip>
</rs_zips>
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<abstract avail="Y" count="1">
<p>Recent unstructured Peer-to-Peer systems, represented by Gnutella and Freenet, offer an administration-free and fault-tolerant application-level overlay network. While elegant from a theoretical perspective, these systems have some serious disadvantages. First, due to knowing very little about the nature of the network topology, the search algorithms operating on these networks result in fatal scaling problems. Second, these systems rely on application-level routing, which may be inefficient with respect to network delays and bandwidth consumption. In this paper, we propose a novel search algorithm, called Split-Prober, to explore the small-world-like topologies of these networks efficiently and scalablely, by turning the power-law degree distributions in these networks to an advantage, and by making discriminative use of nodes according to their different roles in the network. As a result, we are able to reconcile the conflict of remedying the mismatch between the overlay topology and its projection on the underlying physical network, while at the same time navigating these networks with a guaranteed high efficiency and using only local knowledge as cues. Our simulation results indicate that the proposed algorithm outperforms several other well-known methods with significant performance gains.</p>
<p>This paper provides a survey of searchable, peer-to-peer file-sharing systems that offer the user some form of anonymity. We start this survey by giving a brief description of the most popular methods of providing anonymous communication. These include the Ants protocol, Onion routing, Multicasting, MIXes and UDP address spoofing. We then describe a number of implemented systems based on one, or a combination of, these methods. Finally, we discuss possible attacks on the anonymity of these systems and give examples of particular attacks and defences used by the systems we describe.</p>
<p>Most of current structured P2P systems exploit Distributed Hash Table (DHT) to archive an administration-free, fault tolerant overlay network and guarantee to deliver a message to its destination within O(logN) hops. While elegant from a theoretical perspective, those systems face difficulties in a realistic environment. Instead of building P2P overlays from a theoretical perspective, this design tries to construct an overlay from the physical network. By combining different network topology aware techniques, a distinctive overlay structure closely matching the Internet topology is created. The P2P overlay based on this structure is not only highly efficient for routing, but also keeps maintenance overhead very low even under highly dynamic environment.</p>
<p>Micro-payment systems have the potential to provide non-intrusive, high-volume and low-cost pay-as-you-use services for a wide variety of web-based applications. We propose an extension, P2P-NetPay, a micro-payment protocol characterized by off-line processing, suitable for peer-to-peer network services sharing. Our approach provides high performance and security using one-way hashing functions for e-coin encryption. In our P2P-NetPay protocol, each peer's transaction does not involve any broker and double spending is detected during the redeeming transaction. We describe the motivation for P2P-NetPay and describe three transactions of the P2P-NetPay protocol in detail to illustrate the approach. We then discuss future research on this protocol.</p>
<rs_address>Univ Roma La Sapienza, Dipartimento Informat & Sistemist, I-00198 Rome, Italy</rs_address>
<rs_organization>Univ Roma La Sapienza</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Dipartimento Informat & Sistemist</rs_suborganization>
</rs_suborganizations>
<rs_city>Rome</rs_city>
<rs_country>Italy</rs_country>
<rs_zips count="1">
<rs_zip location="BC">I-00198</rs_zip>
</rs_zips>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>We study peer-to-peer data integration, where each peer models an autonomous system that exports data in terms of its own schema, and data interoperation is achieved by means of mappings among the peer schemas, rather than through a global schema. We propose a multi-modal epistemic semantics based on the idea that each peer is conceived as a rational agent that exchanges knowledge/belief with other peers, thus nicely modeling the modular structure of the system. We then address the issue of dealing with possible inconsistencies, and distinguish between two types of inconsistencies, called local and P2P, respectively. We define a nonmonotonic extension of our logic that is able to reason on the beliefs of peers under inconsistency tolerance. Tolerance to local inconsistency essentially means that the presence of inconsistency within one peer does not affect the consistency of the whole system. Tolerance to P2P inconsistency means being able to resolve inconsistencies arising from the interaction between peers. We study query answering and its data complexity in this setting, and we present an algorithm that is sound and complete with respect to the proposed semantics, and optimal with respect to worst-case complexity.</p>
<rs_suborganization>Dept Comp Sci & Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Bombay</rs_city>
<rs_state>Maharashtra</rs_state>
<rs_country>India</rs_country>
<rs_zips count="1">
<rs_zip location="AC">400076</rs_zip>
</rs_zips>
</research>
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<abstract avail="Y" count="1">
<p>In this paper, we present techniques to maintain temporal consistency of replicated objects in data-centric peer-to-peer overlay applications. We consider both structured and unstructured overlay networks, represented by Chord and Gnutella, respectively, and present techniques for maintaining consistency of replicated data objects in the presence of dynamic joins and leaves. We present extensions to the Chord and Gnutella protocol to incorporate our consistency techniques and implement our extensions to Gnutella into a Gtk-Gnutella prototype. Ail experimental evaluation of our techniques shows that: (i) a push-based approach achieves near-perfect fidelity in a stable overlay network, (ii) a hybrid approach based on push and pull achieves high fidelity in highly dynamic overlay networks and (iii) the run-time overheads of our techniques are small, making them it practical choice for overlay networks. (c) 2005 Elsevier B.V. All rights reserved.</p>
<rp_address>Osaka Univ, Grad Sch Informat Sci & Technol, Osaka 5670851, Japan</rp_address>
<rp_organization>Osaka Univ</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Grad Sch Informat Sci & Technol</rp_suborganization>
</rp_suborganizations>
<rp_city>Osaka</rp_city>
<rp_country>Japan</rp_country>
<rp_zips count="1">
<rp_zip location="AC">5670851</rp_zip>
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<research_addrs count="1">
<research>
<rs_address>Osaka Univ, Grad Sch Informat Sci & Technol, Osaka 5670851, Japan</rs_address>
<rs_organization>Osaka Univ</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Grad Sch Informat Sci & Technol</rs_suborganization>
</rs_suborganizations>
<rs_city>Osaka</rs_city>
<rs_country>Japan</rs_country>
<rs_zips count="1">
<rs_zip location="AC">5670851</rs_zip>
</rs_zips>
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<abstract avail="Y" count="1">
<p>As the name suggests, epidemic protocols mimic spread of virus to implement broadcasting with high reliability and low communication cost in peer-to-peer (P2P) overlay networks. In this paper, we study the reliability of epidemic protocols in scale-free networks, an important class of P2P overlay network topologies. In order to improve the robustness of epidemic protocols, we optimize the basic epidemic protocol in the following two ways. One optimization is to introduce an adaptive mechanism that allows each node to retransmit a broadcast message adaptively to the environment. The other optimization is to modify the protocol such that nodes will forward broadcast messages preferentially to neighbor nodes of small degree. The usefulness of these optimizations is demonstrated through simulation results.</p>
<p>In this paper we propose an analytical model for file diffusion in a peer-to-peer (P2P) file-sharing network based on biological epidemics. During the downloading process, the peer shares the downloaded parts of the file and, thus, contributes to distributing it in the network. This behavior is similar to the spreading of epidemic diseases which is a well researched subject in mathematical biology. Unlike other P2P models based on epidemics, we show that steady state assumptions are not sufficient and that the granularity of the diffusion model may be appropriately selected.</p>
<rp_address>Osaka Univ, Grad Sch Informat Sci & Technol, 1-3 Machikaneyama, Toyonaka, Osaka 5608531, Japan</rp_address>
<rp_organization>Osaka Univ</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Grad Sch Informat Sci & Technol</rp_suborganization>
</rp_suborganizations>
<rp_street>1-3 Machikaneyama</rp_street>
<rp_city>Toyonaka</rp_city>
<rp_state>Osaka</rp_state>
<rp_country>Japan</rp_country>
<rp_zips count="1">
<rp_zip location="AP">5608531</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
<research>
<rs_address>Osaka Univ, Grad Sch Informat Sci & Technol, Toyonaka, Osaka 5608531, Japan</rs_address>
<rs_organization>Osaka Univ</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Grad Sch Informat Sci & Technol</rs_suborganization>
</rs_suborganizations>
<rs_city>Toyonaka</rs_city>
<rs_state>Osaka</rs_state>
<rs_country>Japan</rs_country>
<rs_zips count="1">
<rs_zip location="AP">5608531</rs_zip>
</rs_zips>
</research>
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<abstract avail="Y" count="1">
<p>The interest-based clustering is one of promising approaches to achieve low-cost search in peer-to-peer file sharing. It organizes the logical overlay network where peers having similar interests are closely located. In this paper, we propose an interest-based peer clustering algorithm using ant paradigm. Our algorithm is inspired by the ant-based clustering algorithm, which is one of heuristic methods to categorize many data items. We also evaluate this algorithm by simulations.</p>
<rp_address>Huazhong Univ Sci & Technol, Cluster & Grid Comp Lab, Wuhan 430074, Peoples R China</rp_address>
<rp_organization>Huazhong Univ Sci & Technol</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Cluster & Grid Comp Lab</rp_suborganization>
</rp_suborganizations>
<rp_city>Wuhan</rp_city>
<rp_country>Peoples R China</rp_country>
<rp_zips count="1">
<rp_zip location="AC">430074</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
<research>
<rs_address>Huazhong Univ Sci & Technol, Cluster & Grid Comp Lab, Wuhan 430074, Peoples R China</rs_address>
<rs_organization>Huazhong Univ Sci & Technol</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Cluster & Grid Comp Lab</rs_suborganization>
</rs_suborganizations>
<rs_city>Wuhan</rs_city>
<rs_country>Peoples R China</rs_country>
<rs_zips count="1">
<rs_zip location="AC">430074</rs_zip>
</rs_zips>
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<abstract avail="Y" count="1">
<p>The decentralized structure together with the features of self-organization and fault-tolerance makes peer-to-peer network a promising information-sharing model. However, the efficient content-based location remains a challenge of large scale peer-to-peer network. In this paper we present SemreX, a semantic overlay for desktop literature documents sharing in peer-to-peer networks. We present a semantic overlay algorithm by which peers are locally clustered together according to their semantic similarity and long-range connections are rewired for short-cut in the peer-to-peer networks. Experiment results show that routing in the semantic overlay greatly improves the recall of search as well as reduces routing hops and messages.</p>
<rs_suborganization>Sch Elect & Informat Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Beijing</rs_city>
<rs_country>Peoples R China</rs_country>
<rs_zips count="1">
<rs_zip location="AC">100044</rs_zip>
</rs_zips>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>Recent measurement studies show that the object popularity distribution in Kazaa file sharing systems deviates significantly from the Zipf distribution which is commonly seen for the World Wide Web, We measure a real BitTorrent network and we figure its object popularity distribution, which also shows, on a log-log scale, a non-Zipf curve with flattened head. The fetch-at-most-once behavior of peer-to-peer (P2P) client is responsible for such a non-Zipf distribution and we propose two mathematical models to describe this. The models are based on different probability assumptions, though both indicate flatter heads in object popularity distribution curves than Zipf would predict. Our models provide theoretic tools to analyze differences between P2P File-sharing system and Web systems.</p>
<rs_suborganization>Sch Comp Sci & Technol</rs_suborganization>
</rs_suborganizations>
<rs_city>Harbin</rs_city>
<rs_country>Peoples R China</rs_country>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>The process to explore application integration for enterprise information system is called Enterprise Application Integration (EAI). Generally, EAI that based on the peer-to-peer has many limitations, such as poor extensibility, difficulty of management, and high-cost etc. These disadvantages can be overcome by Web services technology which helps to integrate large-scale, distributed enterprise applications together. This paper presents a framework of EAI which based on Web services, and gives discussions on its major functional modules.</p>
<p>In a peer-to-peer inferencesystem, each peer can reason locally but can also lso solicit licit some of its acquatances, which are peers sharing part of its vocabulary. In this paper, we consider peer-to-peer inference systems in which the local theory of each peer is a set et of propositional clauses defined upon a local vocabulary. An important characteristic of peer-to peer infererence systems is that the global theory (the union of all peer theories) is not known (as opposed to partition-based reasoning systems). The main contribution of this paper is to provide the first consequence finding algorithm in a peer-to-peer setting: DeCA. It is anytime and computes consequences gradually from the solicited peer to peers that are more and more distant. We exhibit a sufficient condition on the acquaintance graph of the peer-to-peer inference system for guaranteeing the completeness of this algorithm. Another important contribution is to apply this general distributed reasoning setting to the setting etting of the Semantic Web through the Somewhere semantic peer-to-peer data management system. The last contribution of this paper is to provide an experimental analysis of the scalability of the peer-to-peer infrastructure that we propose, on large networks of 1000 peers.</p>
<p>We describe a new prototype for a zoo information system. The system is based on RFID and allows to retrieve information about the zoo animals in a quick and easy way. RFID tags identifying the respective animals are placed near the animal habitats. Zoo visitors are equipped with PDAs containing RFID readers and WLAN cards. The PDAs may then read the RFID tag IDs and retrieve respective HTML-documents from a zoo Web server showing information about the animals at various levels of detail and languages. Additionally, the system contains a JXTA and XML based peer-to-peer subsystem, enabling zoos to share their content with other zoos in an easy way. This way, the effort for creating multimedia content can be reduced drastically.</p>
<p>Network architectures for collaborative virtual reality have traditionally been dominated by client-server and peer-to-peer approaches, with peer-to-peer strategies typically being favored where minimizing latency is a priority, and client-server where consistency is key. With increasingly sophisticated behavior models and the demand for better support for haptics, we argue that neither approach provides sufficient support for these scenarios and, thus, a hybrid architecture is required. We discuss the relative performance of different distribution strategies in the face of real network conditions and illustrate the problems they face. Finally, we present an architecture that successfully meets many of these challenges and demonstrate its use in a distributed virtual prototyping application which supports simultaneous collaboration for assembly, maintenance, and training applications utilizing haptics.</p>
<p>Previous research, primarily in North America, has found that individual factors (e.g., 'internalising problems') and social factors (e.g., friendship) interact to influence children's levels of peer victimisation. Some research has found that the identity of children's friends and friendship quality (as 'protective factors') are more important than the sheer number of friends. However, studies have produced conflicting findings. A peer nomination inventory was used to assess social skills problems, peer victimisation, peer acceptance, and several different aspects of friendship. Four hundred and forty-nine children aged 9 to 11 years completed the inventory at two time points over the course of an academic year. Social skills problems were found to predict an increase in peer victimisation over time. Two friendship variables were found to moderate this relationship: a) number of friends, and b) the peer acceptance of the very best-friend. The relationship was found to be weaker for those children with lots of friends and for those children with a 'popular' best-friend. The findings advance understanding of the factors that promote peer victimisation.</p>
<rs_address>Univ Bergamo, Dipartimento Gest & Informaz, Bergamo, Italy</rs_address>
<rs_organization>Univ Bergamo</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Dipartimento Gest & Informaz</rs_suborganization>
</rs_suborganizations>
<rs_city>Bergamo</rs_city>
<rs_country>Italy</rs_country>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>Peer-to-peer (P2P) applications are rapidly gaining acceptance among users of Internet-based services, especially because of their capability of exchanging resources while preserving the anonymity of both requesters and providers. However, concerns have been raised about the possibility that malicious users can exploit the network to spread tampered-with resources (e.g., malicious programs and viruses). A considerable amount of research has thus focused on the development of trust and reputation models in P2P networks. In this article, we propose to use fuzzy techniques in the design of reputation systems based on collecting and aggregating peers' opinions. Fuzzy techniques are used in the evaluation and synthesis of all the opinions expressed by peers. The behavior of the proposed system is described by comparison with probabilistic approaches.</p>
<rs_address>Ohio State Univ, Dept Comp Sci & Engn, Columbus, OH 43210 USA</rs_address>
<rs_organization>Ohio State Univ</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Dept Comp Sci & Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Columbus</rs_city>
<rs_state>OH</rs_state>
<rs_country>USA</rs_country>
<rs_zips count="1">
<rs_zip location="AP">43210</rs_zip>
</rs_zips>
</research>
</research_addrs>
<abstract avail="Y" count="2">
<p>The Organic Grid is a biologically inspired and fully decentralized approach to the organization of computation that is based on the autonomous scheduling of strongly mobile agents on a peer-to-peer network. Through the careful design of agent behavior, the emerging organization of the computation can be customized for different classes of applications. In this paper, we report on our experience in adapting the general framework to run two representative applications on our Organic Grid prototype: the National Center for Biotechnology Information (NCBI) basic local alignment search tool (BLAST) code for sequence alignment, and the Cannon's algorithm for matrix multiplication. The first is an example of independent task application, a type of application commonly used for grid scheduling research because of its easily decomposable nature and absence of intra-node communication. The second is a popular block algorithm for parallel matrix multiplication, and represents a challenging application for grid platforms because of its highly structured and synchronous communication pattern.</p>
<p>Agent behavior completely determines the way computation is organized on the Organic Grid. We intentionally chose two applications at opposite ends of the distributed computing spectrum having very different requirements in terms of communication topology, resource use, and response to faults. We detail the design of the agent behavior and show how the different requirements can be satisfied. By encapsulating application code and scheduling functionality into mobile agents, we decouple both computation and scheduling from the underlying grid infrastructure. In the resulting system, every node can inject a computation onto the grid; the computation naturally organizes itself around available resources.</p>
<rs_suborganization>Dept Comp Sci & Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Shanghai</rs_city>
<rs_country>Peoples R China</rs_country>
<rs_zips count="1">
<rs_zip location="AC">200240</rs_zip>
</rs_zips>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>Routing efficiency is the critical issue when constructing peer-to-peer overlay. However, Chord has often been criticized on its careless of routing locality. A routing efficiency enhancement protocol on top of Chord is illustrated in this paper, which is called PChord. PChord aims to achieve better routing efficiency than Chord by exploiting proximity of the underlying network topology. The simulation shows that PChord has achieved lower RDP per message routing.</p>
<rp_address>Tsing Hua Univ, Dept Comp Sci & Technol, Beijing 100084, Peoples R China</rp_address>
<rp_organization>Tsing Hua Univ</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Dept Comp Sci & Technol</rp_suborganization>
</rp_suborganizations>
<rp_city>Beijing</rp_city>
<rp_country>Peoples R China</rp_country>
<rp_zips count="1">
<rp_zip location="AC">100084</rp_zip>
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</reprint>
<research_addrs count="1">
<research>
<rs_address>Tsing Hua Univ, Dept Comp Sci & Technol, Beijing 100084, Peoples R China</rs_address>
<rs_organization>Tsing Hua Univ</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Dept Comp Sci & Technol</rs_suborganization>
</rs_suborganizations>
<rs_city>Beijing</rs_city>
<rs_country>Peoples R China</rs_country>
<rs_zips count="1">
<rs_zip location="AC">100084</rs_zip>
</rs_zips>
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<abstract avail="Y" count="1">
<p>Flash bulk files downloading in style of P2P through perpendicular pattern becomes more popular recently. Many peers download different pieces of shared files from the source in parallel. They try to reconstruct complete files by exchanging needed pieces with other downloading peers. The throughput of entire downloading community, as well as the perceived downloading rate of each peer, greatly depends on uploading bandwidth contributed by every individual peer. Unfortunately, without proper built-in incentive mechanism, peers inherently tend to relentlessly download while intentionally limiting their uploading bandwidth. In this paper, we propose a both effective and efficient incentive approach-Reciprocity, which is only based on end-to-end measurement and reaction: a peer caps uploading rate to each of its peers at the rate that is proportional to its downloading rate from that one. It requires no centralized control, or electronic monetary payment, or certification. Preliminary experiments' results reveal that this approach offers favorable performance for cooperative peers, while effectively punishing defective ones.</p>
<rs_suborganization>Fac Elect Engn & Comp Sci</rs_suborganization>
</rs_suborganizations>
<rs_city>Berlin</rs_city>
<rs_country>Germany</rs_country>
<rs_zips count="1">
<rs_zip location="BC">D-10587</rs_zip>
</rs_zips>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>The paper presents HiPeer, a robust resource distribution and discovery algorithm that can be used for fast and fault-tolerant location of resources in P2P network environments. HiPeer defines a concentric multi-ring overlay networking topology, whereon dynamic network management methods are deployed. In terms of performance, HiPeer delivers of number of lowest bounds. We demonstrate that for any De Bruijn digraph of degree* d >= 2 and diameter** D-DB HiPeer constructs a highly reliable network, where each node maintains a routing table with at most 2d+2 entries independent of the number N of nodes in the system. Further, we show that any existing resource in the network with at most d nodes can be found within at most D-HiPeer = log(d)(N(d - 1) + d) - 1 overlay hops. This result is as close to the Moore bound[1] as the query path length in other outstanding P2P proposals based on the De Bruijn digraphs. Thus, we argue that HiPeer defines a highly connected network with connectivity d and the lowest yet known lookup bound D-HiPeer. Moreover, we show that any node's "join or leave" operation in HiPeer implies a constant expected reorganization cost of the, magnitude order of O(d) control messages.</p>
<p>A fundamental problem in a pure Peer-to-Peer (P2P) file sharing system is how to protect the anonymity of peer nodes when providing efficient data access services. Most of existing work mainly focus on how to provide the initiator anonymity, but neglect the anonymity of the responder. In this paper, we propose a multicast-based protocol, called Mapper, for efficient file sharing with mutual anonymity. By seamlessly combining the technologies of multi-proxy and IP multicast together, the proposed protocol guarantees mutual anonymity during the entire session of file retrieval. Furthermore, Mapper replicates requested files inside the multicast group, so file distribution can be adjusted adaptively and the cost for multicast can be further reduced. Results of both simulations and theoretical analyses demonstrate that Mapper possesses the merits of scalability, reliability, and high adaptability.</p>
<p>Developing a massively multiplayer online game which utilizes physically based simulation to provide realistic behaviors requires numerical integration functions with inherently high computational costs. This simulation, performed on the individual clients of a peer-to-peer networked game or for a client/server online game, presents challenges due to many factors, including limited computing resources at the client level and network latency in the propagation of a client's state to other clients. Computationally intensive simulation may adversely affect performance and result in a situation in which little processing capacity is left for other aspects of the game. in this paper, we explore how a game developer who is aware of these issues might create a game for IBM's recently announced Cell Broadband Engine (TM) processor; we also present an example of the development of a game in which multiple human and robotic characters interact with static and dynamic objects in a virtual environment. Although our experience suggests that porting code to the Cell Broadband Engine core with minimal use of its synergistic processing elements (SPEs) should not be expected to produce significant performance gains at this time, the potential of the Cell SPEs to improve performance is considerable. We discuss performance and design and implementation decisions, with programmability issues being especially noted.</p>
<p>The disruptive advent of peer-to-peer (P2P) file sharing in 2000 attracted significant interest. P2P networks have matured from their initial form, unstructured overlays, to structured overlays like distributed hash tables (DHTs), which are considered state-of-the-art. There are huge efforts to improve their performance. Various P2P applications like distributed storage and application-layer multicast were proposed.</p>
<p>However, little effort was spent to understand the communication abstraction P2P overlays supply. Only when it is understood, the reach of P2P ideas will significantly broaden. Furthermore, this clarification reveals novel approaches and highlights future directions.</p>
<p>In this paper, we reconsider well-known P2P overlays, linking them to insights from distributed systems research. We conclude that the main communication abstraction is that of a virtual address space or application-specific naming. On this basis, P2P systems build a functional layer implementing, for example lookup, indirection and distributed processing. Our insights led us to identify interesting and unexplored points in the design space. Copyright (c) 2004 AEI.</p>
<p>Today, work collaboration is normal practice in developing modern products. Engineering collaborative work involves a number of team members that need to share and exchange design ideas while working with engineering analysis tools such as mechanical computer aided engineering systems. This work presents the M-Sync prototype system that uses an active database approach to enable exchange of engineering information among distributed team members in a timely manner. The distributed data is fully accessible by the local member and is automatically synchronised between different places using a database management system that support event-condition-action (ECA) database rules. Only updates introduced at one location are distributed to other locations, thereby minimizing information transfer and enhancing performance. Members working at different locations can therefore work in a peer-to-peer (P2P) manner and interactively manipulate the same set of information at the same time. (C) 2005 Civil-Comp Ltd and Elsevier Ltd. All rights reserved.</p>
<p>This paper proposes iMobile, a proxy-based platform for developing mobile services for various mobile devices and wireless access technologies. iMobile acts as a message gateway that allows mobile devices to relay messages to each other through various protocols on different access networks. It allows mobile devices to access internet services, corporate databases and to control various network devices. iMobile implements three key abstractions: dev-let, info-let and app-let. An info-let provides abstract view of information space. An app-let implements service or application logic by processing information from various info-lets. A dev-let receives and sends messages through any particular protocols for mobile devices. The let engine supports user and device profiles for personalization and transcoding, and invokes proper app-lets and info-lets to answer requests from a dev-let. The Mobile modular architecture allows developers to write device drivers, information access methods and application logic independently from each other. Copyright (c) 2005 John Wiley & Sons, Ltd.</p>
<rp_suborganization>Dept Sci & Technol Studies</rp_suborganization>
</rp_suborganizations>
<rp_street>Box 510</rp_street>
<rp_city>Gothenburg</rp_city>
<rp_country>Sweden</rp_country>
<rp_zips count="1">
<rp_zip location="BC">S-40530</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
<research>
<rs_address>Calif State Univ, Hayward, CA USA</rs_address>
<rs_organization>Calif State Univ</rs_organization>
<rs_city>Hayward</rs_city>
<rs_state>CA</rs_state>
<rs_country>USA</rs_country>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>This paper studies the conversations and activities of an online support group for breast cancer Sufferers and survivors and their supporters. Using communications medium theory and social capital theory, it examines the mundane and profound exchanges, the poignant self-disclosures, the creative expressions of solidarity, and the minor but not-insignificant political actions of people-initially strangers-who come together as a 'virtuous circle,' not only to assist with medical issues but also to meet emotional and even material needs. Sponsored by the Canadian nonprofit organization Breast Cancer Action Nova Scotia (BCANS), this virtual community has logged over a half million messages since 1996. Not every BCANS participant is an activist-many are just trying to grapple with their disease but some find ways to shatter the professional "information monopoly," and to press for healthcare improvements. The study illustrates the scope, passion, and complexity of peer-to-peer medical communication in a virtual environment that promotes "thick trust". BCANS participants discuss with candor, warmth and even humor Such painful topics as death and dying and the crises in intimate relationships brought about by a terminal illness. The sharing of confidences and fears enables participants to pool their 'collective intelligence' about many things, from how to cope with swelling, to how to think about end-of-life issues, to how to improve social policy. (c) 2005 Elsevier Ltd. All rights reserved.</p>
<p>This paper proposes a stochastic fluid flow model to compute the transfer time distribution of resources in peer-to-peer file sharing applications. The amount of bytes transferred among peers is represented by a continuous quantity (the fluid level) whose flow rate is modulated by a set of discrete states representing the Concurrent. upload and download operations on the peers participating to the transfer. A transient solution of the model is then performed to compute the probability that a peer can download a given resource in less than t units of time as a function of several system parameters. In particular, the impact of file popularity, bandwidth characteristics, concurrent downloads and uploads, cooperation level among peers, and user behavior are included in our model specification.</p>
<p>We also provide numerical results timing at proving the potentialities of the approach we adopted as well as to investigate interesting issues related to the effect of incentive mechanisms on the user cooperation. (C) 2005 Elsevier B.V. All rights reserved.</p>
<p>In this paper we model and Study the performance of peer-to-peer (P2P) file sharing systems in terms of their service capacity'. We identify two regimes of interest: the transient and stationary regimes. We show that in both regimes, the performance of P2P systems exhibits a favorable scaling with the offered load. P2P systems achieve this by efficiently leveraging the service capacity of other peers, who possibly are concurrently downloading the same file. Therefore to improve the performance, it is important to design mechanisms to give peers incentives for sharing/cooperation. One approach is to introduce mechanisms for resource allocation that are 'fair', such that a peer's performance improves with his contributions. We find that some intuitive 'fairness' notions may unexpectedly lead to 'unfair' allocations, which do not provide the right incentives for peers. Thus, implementation of P2P systems may want to compromise the degree of 'fairness' in favor of maintaining system robustness and reducing overheads. (C) 2005 Elsevier B.V. All rights reserved.</p>
<p>There are many structured P2P systems that use DHT technologies to map data items onto the nodes in various ways for scalable routing and location. Most of the systems require 0(log it) hops per lookup request with 0(log it) neighbors per node, where n is the network size. In this paper, we present a constant-degree P2P architecture, namely Cycloid, which emulates a cube-connected cycles (CCC) graph in the routing of lookup requests. It achieves a time complexity of O(d) per lookup request by using O(l) neighbors per node, where n = d x 2(d). We compare Cycloid with other two constant-degree systems, Viceroy and Koorde in various architectural aspects via simulation. Simulation results show that Cycloid has more advantages for large scale and dynamic systems that have frequent node arrivals and departures. In particular, Cycloid delivers a higher location efficiency in the average case and exhibits a more balanced distribution of keys and query loads between the node.,,. (D (C) 2005 Elsevier B.V. All Rights Reserved.</p>
<p>Most P2P systems that provide a DHT abstraction distribute objects randomly among "peer nodes" in a way that results in some nodes having Theta(log N) times as many objects as the average node. Further imbalance may result due to nonuniform distribution of objects in the identifier space and a high degree of heterogeneity in object loads and node capacities. Additionally, a node's load may vary greatly over time since the system can experience continuous insertions and deletions of objects, skewed object arrival patterns, and continuous arrival and departure of nodes.</p>
<p>In this paper, we propose an algorithm for load balancing in such heterogeneous, dynamic P2P systems. Our simulation results show that in the face of rapid arrivals and departures of objects of widely varying load, our algorithm improves load balance by more than an order of magnitude for system utilizations as high as 80% while incurring an overhead of only about 6%. We also show that our distributed algorithm performs only negligibly worse than a similar centralized algorithm, and that node heterogeneity helps, not hurts, the scalability of our algorithm. Although many of these results are dependent on the workload, we believe the efficiency and performance improvement demonstrated over the case of no load balancing shows that our technique holds promise for deployed systems. (C) 2005 Elsevier B.V. All rights reserved.</p>
<p>We quantify the effectiveness of random walks for searching and construction of unstructured peer-to-peer (P2P) networks. We have identified two cases where the use of random walks for searching achieves better results than flooding: (a) when the overlay topology is clustered, and (b) when a client re-issues the same query while its horizon does not change much. Related to the Simulation of random walks is also the distributed computation of aggregates, such as averaging. For construction, we argue that an expander can be maintained dynamically with constant operations per addition. The key technical ingredient Of Our approach is a deep result of stochastic processes indicating that samples taken from consecutive steps of a random walk on an expander graph can achieve statistical properties similar to independent sampling. This property has been previously used in complexity theory for construction of pseudorandom number generators. We reveal another facet of this theory and translate savings in random bits to savings in processing overhead. (C) 2005 Elsevier B.V. All rights reserved.</p>
<rp_address>Rutgers State Univ, Dept Elect & Comp Engn, 628 CORE,94 Brett Rd, Piscataway, NJ 08854 USA</rp_address>
<rp_organization>Rutgers State Univ</rp_organization>
<rp_suborganizations count="1">
<rp_suborganization>Dept Elect & Comp Engn</rp_suborganization>
</rp_suborganizations>
<rp_street>628 CORE,94 Brett Rd</rp_street>
<rp_city>Piscataway</rp_city>
<rp_state>NJ</rp_state>
<rp_country>USA</rp_country>
<rp_zips count="1">
<rp_zip location="AP">08854</rp_zip>
</rp_zips>
</reprint>
<research_addrs count="1">
<research>
<rs_address>Rutgers State Univ, Dept Elect & Comp Engn, Piscataway, NJ 08854 USA</rs_address>
<rs_organization>Rutgers State Univ</rs_organization>
<rs_suborganizations count="1">
<rs_suborganization>Dept Elect & Comp Engn</rs_suborganization>
</rs_suborganizations>
<rs_city>Piscataway</rs_city>
<rs_state>NJ</rs_state>
<rs_country>USA</rs_country>
<rs_zips count="1">
<rs_zip location="AP">08854</rs_zip>
</rs_zips>
</research>
</research_addrs>
<abstract avail="Y" count="1">
<p>Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) cannot detect them accurately. As a result, defend DDoS attacks based on current available IDS will dramatically affect legitimate traffic. In this paper, we propose a distributed approach to defend against distributed denial of service attacks by coordinating across the Internet. Unlike traditional IDS, we detect and stop DDoS attacks within the intermediate network. In the proposed approach, DDoS defence systems are deployed in the network to detect DDoS attacks independently. A gossip based communication mechanism is used to exchange information about network attacks between these independent detection nodes to aggregate information about the overall network attacks observed. Using the aggregated information, the individual defence nodes have approximate information about global network attacks and can stop them more effectively and accurately. To provide reliable, rapid and widespread dissemination of attack information, the system is built as a peer to peer overlay network on top of the internet.</p>