Bob Hertzberger

The distributed ASCI Supercomputer project

The Distributed ASCI Supercomputer (DAS) is a homogeneous wide-area distributed system consisting of four cluster computers at different locations. DAS has been used for research on communication software, parallel languages and programming systems, schedulers, parallel applications, and distributed applications. The paper gives a preview of the most interesting research results obtained so far in the DAS project.

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. By facilitating access to distributed compute and information resources held by multiple organizations, and providing remote experiment control, data management and information retrieval capabilities, it allows scientists to better analyze their data. The ability to use data from multiple sources and correlating these data sets without in-depth domain expertise is a prime goal of the system. This paper describes the design and an implementation prototype of the VLAMG platform. The feasibility of the system is demonstrated by a generalized sample scenario from the chemo-physical analysis domain.

Scientific workflow management: between generality and applicability

In a problem solving environment (PSE), a scientific workflow management system (SWMS) provides a meta environment for managing activities and data in scientific experiments, for prototyping experimental computing systems and for orchestrating the runtime system behaviour. The realisation of a SWMS is often driven by domain specific applications and thus is at application level. Investigating the common characteristics in domain specific SWMSs and encapsulating them in a generic framework improve the reusability of the SWMS components and reduce the costs for introducing an e-science framework in a new science domain. In this position paper, we present our research in an ongoing project: virtual laboratory for e-science (VL-e). In the VL-e project, we are building a generic e-science framework which would support scientists from different domains to share their knowledge and to perform specific experiments. We summarise the lessons we have learned from a previous VL-e implementation, and discuss the plan for improving the quality of the SWMS support in the VL-e framework.

Using Jade agent framework to prototype an e-Science workflow bus

Most of the existing scientific workflow management systems (SWMS) are driven by applications from specific domains and are developed in academic projects. It is challenging to introduce an existing SWMS to a new domain; not only the workflow model and description language do not easily fit in new problem domains, but also the unstable development state of existing systems does not provide all functionality required by the new applications and thus gives high risk for the development. Aggregating different workflow systems as one generic environment enables the sharing on both components and processes between experiments, and promotes the knowledge transfer between domains. A workflow bus approach is to integrate different e-science workflow engines via a software bus. In this paper, we present the basic idea of workflow bus, and discuss how Jade agent framework can be used to prototype the runtime infrastructure of a workflow bus.

WS-VLAM: A GT4 Based Workflow Management System

Generic Grid middleware, e.g., Globus Toolkit 4 (GT4), provides basic services for scientific workflow management systems to discover, store and integrate workflow components. Using the state of the art Grid services can advance the functionality of workflow engine in orchestrating distributed Grid resources. In this paper, we present our work on migrating VLAM-G, a Grid workflow engine based on GT2 to GT4. We discuss how we use the rich set of services provided by GT4 in the new design to realize the user interactivity, interoperability and monitoring. The experiment results show that use cases from previous systems can be migrated seamlessly into the new architecture.

Agent technology and generic workflow management in an e-science environment

In e-Science environments, the support for scientific workflows emerges as a key service for managing experiment data and activities, for prototyping computing systems and for orchestrating the runtime system behaviour. Supporting domain specific applications via a common e-Science infrastructure enables knowledge sharing among different applications, and thus can broaden the range of the application and multiply the impact of scientific research. However, most of the existing workflow management systems are driven by the domain specific applications; the applicability to different domains is limited. In this paper, we discuss possible solutions to this problem and present our research in an ongoing project: Virtual Laboratory for e-Science (VL-e). Agent technologies are used to encapsulate the intelligence for problem solving strategies and for workflow orchestration.

Evaluating the VLAM-G toolkit on the DAS-2

The Grid-based Virtual Laboratory AMsterdam (VLAM-G) provides a science portal for distributed analysis in applied scientific research. DAS-2 is a wide-area distributed computer of 200 Dual Pentium-III nodes, distributed over five Dutch universities. During the iGrid conference, the current reference implementation of VLAM-G was evaluated with an application from the chemo-physical application domain on the DAS-2. It was shown how data flows are instantiated on DAS-2 resources, driven by an information management system that is designed to extract information from raw data sets. Both the information management system and data processing modules are provided by the middleware of the Virtual Laboratory (VL). This paper describes the software and hardware setup of this study, and evaluates the use and performance of the VLAM-G science portal.

Support for Cooperative Experiments in VL-e: From Scientific Workflows to Knowledge Sharing

Recent advances in Internet and Grid technologies have greatly enhanced processes in scientific experiments; not only computing and data intensive tasks become feasible, but also large scale collaborations between resources and users are now possible. Scientific workflows encode intelligence of successful experiments and become important resources. Sharing these resources and allowing scientists to cooperate in one experiment are essential to promote the knowledge transfer among scientists and to accelerate the scientific achievements. In this demo, we present a solution developed in the Dutch Virtual Laboratory for e-Science project for supporting cooperative experiments.

History of the IAS-Society and the IAS-conferences

This paper describes the development of the IAS-Society and the trends in the Intelligent Autonomous Systems conferences. The first IAS conference was held in 1986 and was the first conference on this topic. The Society, founded in 1994, laid the basis for the organization of the IAS conferences. The topics presented at the successive IAS conferences showed clearly the development of the field of Intelligent Autonomous Systems. A short overview is given of the specific topics and percentage of papers in the different research areas in the conferences before and after the year 2000.

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.