Thesis (M.S. in Information Technology Management) Naval Postgraduate School, March 1997. / Thesis advisors, Frank J. Barrett, Nancy C. Roberts. Includes bibliographical references (p. 99-101). Also available online.

Texte remanié de: Doct. Diss.--Göteborg--Göteborg university, 2002. / Bibliogr. à la fin des chapitres.

Mémoire de master en sciences de l'information et des bibliothèques : Services documentaires numériques : Villeurbanne, ENSSIB : 2007. / Texte intégral. Résumé en français et en anglais. Bibliogr. f. 83-86. Sitographie f. 87.

Traditional reliable unicast protocols (e.g., TCP), known as sender-initiated schemes, do not scale well for one-to-many reliable multicast due mainly to implosion losses caused by excessive rate of feedback packets arriving from receivers. So, recent multicast protocols have been devised following the receiver- initiated approach: scalability (in terms of control traffic, protocol state and end-systems processing requirements) is achieved by making the sender independent from receivers; the sender does not know the membership of the destination group. However, this comes with a cost: the lack of knowledge about and control of receivers at the sender has negative implications with respect to throughput, network cost (bandwidth required), and degree of reliability offered to applications. This thesis follows an alternative approach: instead of adopting the receiver-initiated scheme, it greatly enhances the scalability of the sender-initiated scheme, by means of polling-based feedback and hierarchy. The resulting protocol is named PRMP: polling-based Reliable Multicast protocol. Its unique implosion avoidance mechanism polls receivers at carefully planned timing instants achieving a low and uniformly distributed rate of feedback packets. The sender retains controls of receivers: the main PRMP mechanisms are based on a one-to-many sliding window mechanism, which efficiently and elegantly extends the abstraction from reliable unicasting to reliable multicasting. The error control mechanism of PRMP incorporates the use of NACKs and selective, cumulative acknowledgment of packets; additionally, it can wait and judiciously decide between multicast and selective unicast retransmissions. The flow control mechanism prevents unnecessary losses caused by the overrunning of receivers, despite variations in round-trip times and application speeds. The scalability provided by the polling mechanism is further extended by an hierarchic organization to exploit distributed processing and local recovery: receivers are organized according to a tree-structure. However, unlike other tree-based protocols, PRMP is "fully-hierarchic": each parent node forwards data via multicast to its children, and retains/explores the control of and knowledge about its children while autonomously applying error, flow, congestion and session controls in the communication with them. Two congestion control mechanisms, one window-based and another rate-based, have been incorporated to PRMP. As shown through simulation experiments, the resulting protocol q,chieves high though put with cost- effective reliable multicasting. They also show the scalability and effectiveness of PRMP mechanisms. PRMP can achieve reliable multicast with the same kind of reliability guarantees provided by TCP but without incurring prohibitive costs in terms of network cost or recovery latency found in other protocols.

Enterprise intranets have gained popularity in recent times. The growth in size and complexity of these networks, in conjunction with their importance in maintaining business operations, have led to a greater requirement for network management. In addition, the type and severity of problems occurring in these networks have escalated, and the problems are much more difficult to detect. Much of this is attributed to unusual traffic patterns resulting from activity by network users. In the past, detection of network anomalies has relied upon correlation of alarms generated by network devices. More recently, statistical analysis of raw device level network measurements (e.g. variables from the management information bases maintained by network devices) has been explored. Whilst these approaches have proven valuable, they are most suitable for detecting problems, such as network device failures, that are local to the devices where measurements are collected. To complement these techniques a network-wide (or global) approach is required, whereby the dynamic behaviour of a network, in terms of topology and traffic flow, is measured and used for anomaly detection purposes. This method combines flow information taken throughout a network. Such an approach is capable of modelling the behaviour of traffic generated by network users, and hence can better define the cause of certain network anomalies. / This thesis develops a number of graph-based techniques that are capable of measuring the dynamic behaviour of a network and discusses their application in network management. By representing a computer network as a time series of uniquely labelled graphs, it is possible to measure the degree of change that has occurred between a pair of graphs, and hence the dynamics in a network. Concepts introduced include the median graph, intra- and inter- graph clustering, and hierarchical graph representations. The focus is on producing efficient algorithms and improved measures of network change. It is believed that these graph-based techniques for measuring network dynamics have great potential in network anomaly detection, and thus will improve reliability of enterprise intranets. / Thesis (PhDTelecommunications)--University of South Australia, 2006.

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 2000. / Field project. Includes bibliographical references.

Utilization of World Wide Web style Web-Based Intranet Systems (W-BIS) is a rapidly expanding information delivery technique in many organizations. Published reports concerning these systems have cited return on investment values exceeding 1300% and direct payback time periods as low as six to twelve weeks. While these systems have been widely implemented, little theoretically grounded research has been conducted in relation to users' acceptance, utilization or the perceived quality of these systems. The study employed a two-site investigation of corporate Web-Based Intranet Systems, with surveys distributed via the traditional mail system. The complete survey instrument distributed to employees included the ServQual/ServPerf, User Information Satisfaction, Ease of Use/Usefulness, and Computer Playfulness instruments. In addition to these previously developed instruments, the survey instrument for this study included measures of Web-Based Intranet Systems utilization and usefulness along with respondent demographics and subordinate-reported managerial commitment. This study investigated the reliability and validity of the ServQual/ServPerf instrument in an information systems service environment. The same analysis was conducted of the more generally accepted User Information Satisfaction instrument.

Rapport de stage DESS : Ingénierie documentaire : Ecole nationale supérieure des sciences de l'information et des bibliothèques, Université Claude Bernard Lyon 1 : 2001.

Projet professionnel personnel de bibliothécaire : dossier d'aide à la décision : Villeurbanne, ENSSIB : 2002.

Thesis (M.S.)--Kutztown University of Pennsylvania, 1998. / Source: Masters Abstracts International, Volume: 45-06, page: 2700. Typescript. Abstract precedes thesis as preliminary leaves [1-2]. Includes bibliographical references (leaves 75-77).