The effect of seff-similar traffic on the delay of a single queue system is studied through the use of the measured traffic and models as input process. A model-driven simulation-based method is then proposed for the computation of mean line delay in a network design. Both the hybrid-FGN and the FARIMA algorithms have been used to synthesize self-similar sample paths. The comparison results with real-traffic data sets firmly establish the usefulness of the proposed model-driven simulation-based method. A practical database method is also introduced that helps the designer to determine the parameters in network design. This approach may play an important role in network design and analysis.

Recent extensive measurements of real-life traffic demonstrate that the probability density function of the traffic is noa-Gaussian. If a traffic model does not capture this characteristics, any analytical or simulation results will not be accurate. In this work, we study the impact of non-Gausslan traffic on network performance, and present an approach that can accurately model the marginal distribution of real-life traffic. Both the long- and short-range autocorrelations are also accounted. We show that the removal of non-Gaussian components of the process does not change its correlation structure, and we validate our promising procedure by simulations.

RSX-DAS is a flexible CAMAC-based data acquisition software system that runs on a variety of PDP-11 architectures and under RSX-11 operating systems. Since 1983, five versions of RSX-DAS have been developed at tile Plasma Physics Laboratory, University of California, Los Angeles, U.S.A. and the Institute of Plasma Physics, Academia Sinica, China. The system has modular, multi-tasking and concurrent processing features. The commnunication among seventeen tasks is accomplished through parent/offspring tasking, event flags and shared regions. The user interface to RSX-DAS consists of a set of user friendly commands, indirect command files and menus. The database consists of four static shared regions for the control of data acquisition and display, one dynamic shared region for the data of current shot, and data files for previous shots. The moduiarity of the CAMAC interface software allows operation on several CAMAC organizations, for example a parallel branch or some dedicated crates, and allows easy addition and subtraction of CAMAC hardware.

A new object-oriented Real Time System Simulator (RTSS) with the capability for simulation graphics and animation, has been developed and used for modeling the distributed data acquisition and processing systems at JET and AS]PP. Simulation allows estimates of response time, throughput and resource utilization for a variety of configurations to be investigated. Performance measurements, simulation and analysis are used together to calibrate and validate each other.

The HT-7U data system is being designed to support the HT-7U superconducting tokamak. For the HT-7U to achieve its mission of extremely long pulse and steady-state operation, the HT-7U data system must be flexible and robust. Corresponding to the various operation modes of the HT-7U experiment, a variety of system configurations and workload models are considered. A trace-driven simulation-based method and steady-state operational analysis technique is used for performance evaluation. These analyses show that much better performance may be obtained by applying the performance optimization techniques of fast switching networking, data compression, caching/buffering, pipelining, a real-time operating system, a real-time database, etc.

In this paper, a QoS multipath source routing protocol (QoS-MSR) is proposed for ad hoc networks. It can collect QoS information through route discovery mechanism of multipath source routing (MSR) and establish QoS route with reserved bandwidth. In order to reserve bandwidth efficiently, a bandwidth reservation approach called the multipath bandwidth splitting reservation (MBSR) is presented, under which the overall bandwidth request is split into several smaller bandwidth requests among multiple paths. In simulations, the anthors introduce Insignia, an in-bind signaling system that supports QoS in ad hoc networks, and extend it to multipath Insignia (M-Insignia) with QoS-MSR and MBSR. The results show that QoS-MSR routing protocol with the MBSR algorithm can improve the call admission ratio of QoS traffic, the packet delivery ratio, and the end-to-end delay of both best-effort traffic and QoS traffic. Therefore, QoS-MSR with MBSR is an efficient mechanism that supports QoS for ad hoc networks.

The paper deals with the design and implementation of the machine control system for the HT-7 tokamak, at present under construction in Hefei, China. This is a distributed system which achieves a balance between performance and cost. A powerful UNIX workstation with a CAMAC serial highway serves as the system supervisor. Man-machine interface is based on the industry standard X Window system. Programmable logical controllers are used for subsystems.

This paper describes a high-speed data acquisition and processing system which has been successfully operated on the HT-6M tokamak fusion experimental devicc. The system collects, archives and analyzes up to 512 kilobytes of data from each shot of the experiment. A shot lasts 50-150 milliseconds and occurs every 5-10 minutes. The system consists of two PDP-11/24 computer systems. One PDP-II/24 is used for real-time data taking and on-line data analysis. It is based upon five CAMAC crates organized into a parallel branch. Another PDP-II/24 is used for off-line data processing. Both data acquisition software RSX-DAS and data processing software RSX-DAP have modular, multi-tasking and concurrent processing features.

A flexible modelling software for pulsed data acquisition is based on an event-driven simulator. It can be used to simulate a wide variety of systems which can be modelled as open queueing networks. This paper also describes some modelling program techniques and applications in plasma physics laboratories.