Andreas Schreiber

The provenance of electronic data

It would include details of the processes that produced electronic data as far back as the beginning of time or at least the epoch of provenance awareness.

Open source software framework for applications in aeronautics and space

The DLR developed the open source software framework RCE to support the collaborative and distributed work in the shipyard industry. From a technology side of view a software from the shipbuilding field has many requirements in common with aerospace software projects. Accordingly, RCE has become the basis for further projects within the DLR. Over the last years of usage a subset of frequently used software components could be derived and are provided by the RCE framework. In particular, the workflow engine, allowing the integration of different domain-specific tools from local and remote locations into one overall calculation has become important for various projects. We present RCE and show how its software components are reused in two aerospace applications.

Provenance implementation in a scientific simulation environment

Many of todays engineering applications for simulations are lacking machanisms to trace the generation of results and the underlying processes. Especially computations conducted in distribued computing environments as Grids are lacking suitable means to keep track of used resources. Trust of engineers in results produced within distribued simulation environments is very limited without this information. This paper will demonstrate how trust and confidence in simulation results could be achived for engineering applications. It will highlight the backgrounds of the application, of provenance recording, the mapping to the application, and finally the implementation of provenance awareness for the application. Additionally it will present examples of analyzing the information stored to be of further use to the engineer.

The Distributed Engineering Framework TENT

The paper describes TENT, a component-based framework for the integration of technical applications. TENT allows the engineer to design, automate, control, and steer technical workflows interactively. The applications are therefore encapsulated in order to build components which conform to the TENT component architecture. The engineer can combine the components to workflows in a graphical user interface. The framework manages and controls a distributed workflow on arbitrary computing resources within the network. Due to the utilization of CORBA, TENT supports all state-of-the-art programming languages, operating systems, and hardware architectures. It is designed to deal with parallel and sequential programming paradigms, as well as with massive data exchange. TENT is used for workflow integration in several projects, for CFD workflows in turbine engine and aircraft design, in the modeling of combustion chambers, and for virtual automobile prototyping.

A problem solving environment for multidisciplinary coupled simulations in computational grids

This paper describes a software environment for doing multidisciplinary coupled simulations in computational grids using a combination of various existing software tools.The environment consists of the software integration system TENT for setting up, steering and monitoring the simulation, the code coupling library MpCCI for the numerical coupling of simulation codes, and the MPI implementation MPICH-G2 and the Globus Toolkit for running the coupled codes in distributed environments.

A Python Library for Provenance Recording and Querying

In many application domains the provenance of data plays an important role. It is often required to get store detailed information of the underlying processes that led to the data (e.g., results of numerical simulations) for the purpose of documentation or checking the process for compliance to applicable regulations. Especially in science and engineering more and more applications are being developed in Python, which is used either for development of the whole application or as a glue language for coordinating codes written in other programming languages. To easily integrate provenance recording into applications developed in Python, a provenance client library with a suitable Python API is useful. In this paper we present such a Python client library for recording and querying provenance information. We show an exemplary application, explain the overall architecture of the library, and give some details on the technologies used for the implementation.

A Dynamic Data Integration Approach to Build Scientific Workflow Systems

The need for collaboration between individual scientificfields increases with the wish for more global engineeringoptimizations and assessment requirements. Since areas ofresearch become more and more fine-grained domains ofthere own, it is still very desirable to cooperate with otherexperts with more chance than ever to gain synergies whenscience is scattered as today. But this exchange of knowl-edge comes only into consideration if it can be used in asimple way with at most an moderate initial effort. To thisend a framework is developed that lets scientists easily useknowledge of others without the need to understand theirwork and technology completely. Furthermore a genericcommon data format based on XML technology is devel-oped for exchanging and storing data between differentdomain-specific applications. To support all implementers,a twofold abstraction layer was introduced to encapsulatetheir knowledge shielding it from the technical environment.

RepoGuard: A Framework for Integration of Development Tools with Source Code Repositories

Today modern software development is not possible without the aid of tools like version control systems, bug tracking systems or instruments that ensure the compliance with code conventions. Unfortunately, all of these tools “live in their own world”, are only loosely coupled and do not interact with each other. RepoGuard addresses this problem by linking version control systems to other software development tools. It is implemented as an extension to several version control systems and provides interfaces to integrate other tools. The use of RepoGuard allows maximum control and validation of all committed resources before they are permanently stored. Additionally, RepoGuard provides communication channels in order to inform all relevant stakeholders about the failure or success of the process. Overall, RepoGuard provides simple but effective means to guarantee software quality standards in distributed development processes.

Requirements for a Provenance Visualization Component

The need for interpretation of provenance data increases with the introduction of further provenance related IT-systems. The interpretation of data only becomes intuitively with providing good and efficient visualization possibilities. During the development of general provenance visualization techniques, provenance users are classified into groups regarding their view to provenance information. The end-user requirements are evaluated on an abstract level to have a basis for research. Different intentions of end-users regarding provenance are identified and put into relationship with standard visualization types. Examples for standard visualization types are given and a brief forecast to future achievements is made.

Techniques for wrapping scientific applications to CORBA components

This paper presents wrapping techniques that we have developed in order to integrate applications into the scientific workflow management system TENT. These techniques take into account the varying degrees of controllability found for each application and utilize various kinds of communication mechanisms between application and the associated wrapper. We also give an outline of the principles of component technology employed in the CORBA based TENT environment. In addition, the means by which applications can be connected through their associated wrappers and TENT components to form distributed workflows are presented. It is demonstrated how TENT provides the user with a homogeneous perspective on scientific workflows running in a distributed environment and how he is enabled to efficiently configure and control these workflows by means of the TENT component model.