Wings for Pegasus: Creating Large-Scale Scientific Applications Using Semantic Representations of Computational Workflows, Y. Gil, V. Ratnakar, E. Deelman, G. Mehta, J. Kim. Proceedings of IAAI 2007.
Scientific workflows provide scientists a problem solving environment where they can reuse the shared data repositories, services and computing resources. Creating and validating these workflows is a real challenge. Some of these workflows can contain thousands of nodes as well as repetitive structures. This paper gives a high level introduction to Wings and Pegasus system and its 3 step abstractions of workflow execution. Then the paper presents a novel approach using semantic technologies to express repetitive computing structures in the workflows and a mechanism to expand those repetitive structures based on the meta data (number of data slices) of the input data files. Paper also introduces the concept of interleaving the execution and generation of workflows based on the intermediate data. Examples are given for the usage of this system in the fields of earth quake prediction & natural language processing.
Artificial Intelligence and Grids:Workflow Planning and Beyond, IEEE Intelligent Systems By Yolanda Gil , Ewa Deelman , Jim Blythe , Carl Kesselman , Hongsuda Tangmunarunkit. Issue Date:January 2004