H. Yakali

VLAM-G: A Grid-based virtual laboratory

The Grid-based Virtual Laboratory AMsterdam (VLAM-G), provides a science portal for distributed analysis in applied scientific research. It offers scientists remote experiment control, data management facilities and access to distributed resources by providing cross-institutional integration of information and resources in a familiar environment. The main goal is to provide a unique integration of existing standards and software packages. This paper describes the design and prototype implementation of the VLAM-G platform. In this testbed we applied several recent technologies such as the Globus toolkit, enhanced federated database systems, and visualization and simulation techniques. Several domain specific case studies are described in some detail. Information management will be discussed separately in a forthcoming paper.

A hierarchical view on modeling the reliability of a DSRC link for ETC applications

For electronic payments, the communication link has to be reliable. Dedicated short-range communication (DSRC) is a proposed solution for the automatic debiting of vehicles in an electronic toll collection (ETC) system without disturbing the traffic flow. The requirements on the reliability of such a system are high, which implies that only large-scale simulations with a lot of detail are effective for analyzing occasional errors. In this paper, a hierarchical approach is worked out that allows such simulations of the communication link, with a 80% reduction of the computational effort compared to simulation with full detail.

High Performance Discrete Event Simulations to Evaluate Complex Industrial Systems

We have developed a Modelling and Simulation platform for technical evaluation of Electronic Toll Collection on Motor Highways. This platform is used in a project of the Dutch government to assess the technical feasibility of Toll Collection systems proposed by industry. Motivated by this work we introduce the concept of High Performance Discrete Event Simulations to evaluate the performance of Complex Industrial Systems. We assume that the elements have well-known behaviour, and demand that the interaction between the elements is well-known and their state changes at pre-definable time intervals. As a result we can model the total complex system as a discrete event model. We present the case of Automatic Debiting Systems for Electronic Toll Collection and introduce the modelling approach, the simulation environment (ADS-SIM), and discuss the need for HPC to carry out such simulations.

The Measurement Architecture of the Virtual Traffic Laboratory

In this paper we introduce the measurement architecuture of an application for the Virtual Traffic Laboratory. We have seamlessly integrated the analyses of aggregated information from simulation and measurements in a Matlab environment in which one can concentrate on finding the dependencies of the different parameters, select subsets in the measurements, and extrapolate the measurements via simulation. Available aggregated information is directly displayed and new aggregate information, produced in the background, is displayed as soon as it is available.

An Experiment for the Virtual Traffic Laboratory: Calibrating Speed Dependency on Heavy Traffic: A Demonstration of a Study in a Data Driven Traffic Analysis

In this paper we introduce an application for the Virtual Traffic Laboratory. We have seamlessly integrated the analyses of aggregated information from simulation and measurements in a Matlab environment, in which one can concentrate on finding the dependencies of the different parameters, select subsets in the measurements, and extrapolate the measurements via simulation. Available aggregated information is directly displayed and new aggregate information, produced in the background, is displayed as soon as it is available.

The reliability of a DSRC-link for ETC applications modelled on 5 levels of detail

For electronic payments, the communication link has to be reliable. Dedicated short range communication is a proposed solution for the automatic debiting of vehicles without disturbing the traffic flow. The reliability requirements of such a system are high, which implies that only large scale simulations with a lot of detail are effective to analyse an occasional error. In the article, a hierarchical approach is worked out that allows such simulations of the communication link with a 80% reduction of the computational effort compared to simulation with full detail.