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Due to the World Wide Web (WWW) has expanded speedily, the interaction between the user and the Web site is becoming persistently. Most proposed load control schemes developed based on the traditional Web site providing static files are not suitable for the Web site today. The new generation of WWW provides more varied and secure services. The greater part of applications are belonging to the session-based service. In order to provide better quality of services for the users, Web cluster architecture becomes the popular solution for most Web sites. This architecture combines serveral servers to work together and deals satisfied with the exponential increasing in service on WWW. In this paper, we proposed a session-based admission control and load balancing mechanism for Web cluster systems. The admission control scheme is used to prevent Web system from becoming overload by determining whether an establishment of TCP connection is admitted or not. The load balancing scheme assigns new sessions to the suitable back-end server and achieves good load balancing among back-end servers, which also increases the throughput of system. The simulation results demonstrate that our mechanism utilizes system resource efficiently and takes system utilization and percentage of completed session into account simultaneously. Therefore, our mechanism can ensure the sessions would not be aborted midway. To compare with others, our mechanism can attain higher throughput and maintain the request average delay time. Furthermore, whether the back-end servers are identical in capacity or not, their load always get good balance.

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<p>Det uppkommer ideligen innovativa tekniker för att utveckla möjligheterna att erhålla större förtjänst utifrån sitt agerande för företag och organisationer. En av teknikerna är webb-baserade informationssystem. Syftet med detta projekt är att undersöka huruvida traditionella systemutvecklingsmetoder stödjer utvecklingen av webb-baserade informationssystem och om dessa metoder används i arbetet med att utveckla webb-baserade informationssystem.</p><p>För att erhålla en bättre överblick av problemet och för att kunna definiera en problemställning inleddes undersökningen med att studera tillgänglig litteratur. Problemställningen besvarades genom svar som inhämtades från ett antal intervjuer, vilka genomfördes med företag som arbetar med utveckling av webb-baserade informationssystem, samt den information som erhölls från litteraturstudien.</p><p>Arbetet har förts på en strategisk nivå där de tekniska lösningarna inte har diskuterats i detalj, dock finns det vissa tekniska beskrivningar för att göra rapporten tydligare. Ett resultat som undersökningen givit är att traditionella systemutvecklingsmetoder används, men då förädlade i nya former för att tillse utvecklingen av webb-baserade informationssystem. Ytterligare ett resultat gav ett tydligt anspråk av ett iterativt arbetssätt vid utveckling av webb-baserade informationssystem.</p>

<p>This thesis explores the use of the World Wide Web asinfrastructure for collaboration among small or middle sizedgroups. A collection of Web-based tools has been developed,whose main characteristic is that they allow users to makeannotations to shared documents. These Web annotations form adialogue that is persistent and immediately accessible to theusers. Special interest has been devoted to observing howcollaborators make use of a common space where Web-documents aswell as Web-annotations are organized and stored. This commonspace has been called a domain.</p><p>We have also tried a novel method for the design ofcollaborative Web-based systems, called“designing frominside”. It is based on communication between the usersand the designer in the form of a dialogue, which is generatedand presented“inside”the system that is beingdeveloped. In this way, users can make comments about theirexperience using the tool while in the appropriate context.Comments by the users as well as the designer's replies areshared with other users. In this way the users become involvedunobtrusively in the design process of the tool.</p><p>One of the tools, DHS, has been used in longitudinal studieswithin courses where students also met regularly in theclassroom. In one contextthe students used the DHS as adiscussion or annotation tool for documents that they hadwritten. Within this framework, we also explored how secondlanguage students collaboratively made use of the tool toaccomplish a task that is normally done individually (readingcomprehension).</p><p>Col·lecció is the latest version of the DHS. Themost important change in this tool is that users can add theWeb-documents to the domain themselves. This gives a newperspective to the tools because it can work as a collectivebookmark system. This system has been used in three casestudies in which a distributed and co-located group discussed acollection of Web-documents.</p><p>Another system in the family is Col·laboració,which is oriented to supporting collaborative writing tasks. Itfocuses primarily on the communication needs co-authors mighthave around a shared document that is being produced. Thesystem also allows for on-line revision and for generatingversions of the document. This system has been used in 8 casestudies, where we have observed the users’interaction andexplored the possibilities that the Web offers to collaborativewriting. For example, co-authors can use the commenting spaceas a“window to the Web”, as the Web provides a hugeamount of information that can be relevant during the writingprocess.</p><p>One of the characteristics of all these tools is that theypresent the comments in chronological order. No threadingmechanism is used, although several users have requested athreaded presentation of the comments. This design choice isbased on the belief that with threading of comments, the focusof the discussion could drastically divert from its originaltopic, the document. In our observations, a dual discoursecontext is often found in the comments referring both to aprevious comment and to the shared document. To facilitateorientation in the discussions, we have also developed avisualization tool called Domain Interactivity Diagram (DID),designed to work together with the other systems.</p><p>The studies show that the Web offers a suitableinfrastructure for text-based discussions in which the documentcan be given a prime role. It also emerged that the integrationof email was appreciated by users mainly because it wasconsidered as a reminder of the task. In educational settings,students valued the possibility to go through many exampleswritten by other students in comparison with the traditionalway. Also the dialogue formed by the comments was astraightforward way to promote collaboration amongstudents.</p><p>WWW, discussion, annotation, design, writing, collaborativework, asynchronous communication, text-based communication.</p>

Overview about the use of XML; New possibilities for Digital Libraries; Introduction to basic concepts of XML and SGML

Dieser Vortrag gibt eine kleine Uebersicht ueber die Einsatzmoeglichkeiten von Linux im Netz - sowohl als Client als auch als Server.

Gemeinsamer Workshop von Universitaetsrechenzentrum und Professur Rechnernetze und verteilte Systeme (Fakultaet fuer Informatik) der TU Chemnitz. Workshop-Thema: Infrastruktur der ¨Digitalen Universitaet¨ WWW Privacy - P3P Platform of Privacy Preferencers Der Vortrag soll einen Einblick in das z.Zt. noch in der Entwicklung stehenden Protokolls P3P des W3C geben. Dabei wird das Grundprinzip von P3P, einige technische Realisierungsmoeglichkeiten sowie ein Demo-Einkaufssystem vorgestellt.

This thesis is driven by the motivation to explore a way of working collaboratively that closely reflects the World Wide Web (WWW), more specifically the potential of the Web architecture built on Semantic Web technologies and Linked Data. The goal is to describe a generic approach and architecture that satisfies the needs for loose collaboration and collective knowledge construction as exemplified by the applications described in this thesis. This thesis focuses on a contribution-centric architecture which allows for flexible applications that support loose forms of collaboration. The first research question deals with how Web-based collective knowledge construction can be supported. The second research question explores the characteristics of collective knowledge construction with respect to the Open World Assumption (OWA). The OWA implies that complete knowledge about a subject cannot be assumed at any time, which is one of the most fundamental properties of the WWW. The third research question investigates how Semantic Web technologies be used in order to support such a contribution-centric architecture. The thesis and its underlying publications are of a technical character and are always grounded in theoretical models and considerations that have led to functional implementations. The research has evolved in iterative development processes and was explicitly directed at building applications that can be used in collaborative settings and that are based on standardized Web technologies. One of the main outcomes, an information model, was developed together with such an application and provides a number of novel approaches in the context in which it was designed. The validity of the presented research is supported by evaluations from different perspectives: a list of implemented applications and showcases, results from structured interviews that have investigated the suitability for various resource annotation processes, as well as scalability aspects. The thesis concludes that it is ultimately up to the application how "loose" the collaboration should be and to which extent the OWA is incorporated. The presented architecture provides a toolkit to support the development of loosely collaborative applications. The showcased applications allow the construction of collaborative conceptual models and to collaboratively annotate educational resources. They show the potential of the used technology stack and the introduced contribution-centric architecture that sits on top if it. / <p>QC 20140417</p>

Zugl.: Kassel, Universiẗat, Habil.-Schr., 2008 u.d.T.: Schellhase, Jörg: Potenziale und Grenzen der Recherche wissenschaftlicher Publikationen unter besonderer Berücksichtigung Web-basierter Recherchesysteme.