Herwig Unger

Two-level communication protocol for a Web operating system (WOS/sup TM/)

The World Wide Web consists not only of informational, but also computational resources. However these resources, especially computational ones are underutilized. One characteristic of the Web is its ever changing structure; for instance, nodes are dynamically added and removed. This makes it difficult, if not impossible, to draw a complete and accurate picture of available resources. We consider the Web as a versioned system: resources, services and protocols are versioned. This paper presents a two-level protocol within this framework. The first protocol, the WOS Request Protocol (WOSRP), allows to select an appropriate version of a server. The second protocol, the WOS Protocol (WOSP), allows for locating and using these distributed (informational and computational) resources. We show how the latter protocol provides an efficient fault-tolerant resource search mechanism.

Innovative Internet Computing Systems

In this paper, we present a document metaphor called Living Documents for accessing and searching for digital documents in modern distributed information systems. Our approach is based upon a finegrained document concept which glues computational services, data and meta data together. Viewing documents as micro servers is particularly well suited in environments where the document’s content is changing continuously and frequently. Based on a case study of an existing stateof-the-art Web application, we show how to transform database-centric information systems into a hypertext of inter-linked Living Documents. We also discuss how to effectively use traditional as well as Web information retrieval techniques, namely topic distillation, in such hypertext environment. In particular, an extended version of Kleinberg’s [11] algo-

About the Value of Virtual Communities in P2P Networks

The recently introduced peer-to-peer (P2P) systems are currently the most popular Internet applications. This contribution is intended to show that such decentralized architecture could be served as a suitable structure to support virtual communities.

Search in Communities: An Approach Derived from the Physic Analogue of Thermal Fields

Peer-to peer communities are used to share information between users with common interests. This article describes an approach to locate nodes which are frequently accessed and therefore keep very new and/or important information for the community. Using an approach derived from the physic analogue of thermal field, the search for this attractive nodes becomes faster and creates a self organizing system for a more efficient information management.

Message Chains and Disjunct Paths for Increasing Communication Performance in Large Networks

In this paper we propose a simple powerful method to increase communication performance in large networks such as the Internet. Our approach is based on the usage multiple disjunct paths for the transmitting data from one node to another one. The method exploits the dense connectivity of the Internet by making use of the different routes engaged in communications originating from different nodes to one target nodes. We show that depending on the bandwidth offered and the amount of data to be transfered, a linear speedup can be achieved. An experimentalimpl ementation of the method within the WOS framework confirms the theoreticalanal ysis of the method.

Learning of winning strategies for terminal games with linear-size memory

We prove that if one or more players in a locally finite positional game have winning strategies, then they can find it by themselves, not losing more than a bounded number of plays and not using more than a linear-size memory, independently of the strategies applied by the other players. We design two algorithms for learning how to win. One of them can also be modified to determine a strategy that achieves a draw, provided that no winning strategy exists for the player in question but with properly chosen moves a draw can be ensured from the starting position. If a drawing- or winning strategy exists, then it is learnt after no more than a linear number of plays lost (linear in the number of edges of the game graph).

Content-Oriented self-organization in unstructured p2p data sharing systems. an approach to improve resource discovery

The flooding-based search is a major problem in unstructured peer-to-peer file sharing systems like Gnutella or KaZaa since it results in a significant portion of Internet traffic. This article intended to demonstrate that flooding can be avoided by using a content-oriented self-organization mechanism. In contrast to connections that are usually made randomly between peers in unstructured systems, each peer set up its connections based on content interests represented by offered and downloaded files. Through the simulation, it was shown that these local activities resulted in a global content-related network topology even under highly dynamic conditions. It was demonstrated that the content-oriented topology could be used to organize focused search in order to avoid flooding.

Advanced Distributed Systems

Database Systems.- Database System Architecture - A Walk Through Time: From Centralized Platform to Mobile Computing - Keynote Address.- Extending Wide-Area Replication Support with Mobility and Improved Recovery.- Extending Databases to Precision-Controlled Retrieval of Qualitative Information.- An Approach for Solving Very Large Scale Instances of the Design Distribution Problem for Distributed Database Systems.- Distributed and Parallel Algorithms.- On the Abstraction of Message-Passing Communications Using Algorithmic Skeletons.- Implementing Distributed Mutual Exclusion on Multithreaded Environments: The Alien-Threads Approach.- On Time Analysis of Random Walk Based Token Circulation Algorithms.- Architecture for Media Streaming Delivery over P2P Networks.- On the Role of Information Compaction to Intrusion Detection.- A Hybrid Framework of RR Scheduler to Ensure Priority, Low Complexity and Delay with Relative Fairness.- Data Hiding in Identification and Offset IP Fields.- Interpretation of UML Sequence Diagrams as Causality Flows.- Real-Time Distributed Systems.- A Proposal for On-Line Reconfiguration Based upon a Modification of Planning Scheduler and Fuzzy Logic Control Law Response.- Integrated Tool for Testing Timed Systems.- Conformance Testing of Real-Time Component Based Systems.- Cooperative Information Systems.- Modeling Multiple Interactions Using Coloured Petri Nets: A Case Study.- A Framework for Information Integration with Uncertainty.- Model Fragmentation for Distributed Workflow Execution: A Petri Net Approach.- An Online Component Deployment System for Dynamic Collaborative Sessions.- Complexity in Collaborative Online Socio-Interationist Environments: A Good Reason for Distributed Systems.- Fault Tolerance.- Injecting Communication Faults to Experimentally Validate Java Distributed Applications.- Implementing Rollback-Recovery Coordinated Checkpoints.- Information Retrieval.- An Identity-Based Model for Grid Security Infrastructure.- Lineage Tracing in Mediator-Based Information Integration Systems.- Combining Sources of Evidence for Recognition of Relevant Passages in Texts.- A Hierarchical and by Role Multi-agent Organization: Application to the Information Retrieval.- Modeling and Simulation.- Evaluating a Scientific SPMD Application on a Computational Grid with Different Load Balancing Techniques.- Increasing the Training Speed of SVM, the Zoutendijk Algorithm Case.- Video Motion Detection Using the Algorithm of Discrimination and the Hamming Distance.- An Efficient and Grain Preservation Mapping Algorithm: From ER Diagram to Multidimensional Model.- Quadratic Optimization Fine Tuning for the Learning Phase of SVM.- Wireless Networks and Mobile Computing.- WFCTA(Weighted Fair Channel Time Allocation) and Its Analysis for HR-WPAN.- Performance Analysis of Two Approaches to Service Discovery in Mobile Ad Hoc Networks.- BCTMA (Bi-directional Cut-Through Medium Access) Protocol for 802.11-Based Multi-hop Wireless Networks.- Some Security Issues of Wireless Systems.- Overview the Key Management in Ad Hoc Networks.- On Performance Improvement for 802.11-based Multi-hop Ad Hoc Wireless Networks.- Analysis of Context Transfer in Seamless IP Mobility.- Artificial Life and Multi-agent Systems.- An Introduction to Evolutionary Algorithms and Their Applications.- Distributed Anticipatory System.- Memory as an Active Component of a Behavioral Animation System.- Growing Functional Modules, a Prospective Paradigm for Epigenetic Artificial Intelligence.- Specifying Agents Goals in 3D Scenarios Using Process Algebras.- A New Approach for Offer Evaluation in Multi-agent System Negotiation Based in Evidential Paraconsistent Logic.- A Voice-Enabled Assistant in a Multi-agent System for e-Government Services.- CAS - An Interface Generator in Natural Language to Information System.- A Formal Approach to Model Multiagent Interactions Using the B Formal Method.- Behavioral Self-control of Agent-Based Virtual Pedestrians.- ISSADS 2004.- Security Challenges of Distributed e-Learning Systems.- A Component-Based Transactional Service, Including Advanced Transactional Models.

The Web Operating System - WOS

The rapid development and the heterogeneous nature of the Web ensure that it is impossible to develop a complete catalog of all of the resources and services available on the Web. As a result, no single operating system can be used for Web computation, since it will necessarily be incomplete. Furthermore, it is unclear that such an operating system would even be useful, considering the different levels of granularity of service that need to be provided.