Visualization Science Case
This visualization-oriented workflow makes use of VisIVO tools for the production and visualization of tomographic images aimed at inspecting the cargo containers carrying high atomic number materials. The VisIVO tools provide the execution of a comprehensive collection of modules for the processing and visualization of Astrophysical and Astroparticle datasets on DCIs.
The VisIVO Muon Workflow Graph (WS-PGRADE)
This workflow is executed in the VisIVO Science Gateway. This Science Gateway is a web-based workflow-enabled framework where a large-scale of multidimensional datasets and applications are integrated for the visualization and data filtering on Distributed Computing Infrastructures (DCIs). Advanced users are enabled to create, change, invoke, and monitor workflows; standard users, instead, are provided with easy-to-use specific web based user interfaces hiding all technical aspects of the visualization software and of the configuration and settings of the DCIs.
The Muon application workflow performs a visual analysis of simulation data resulting from a scattering of cosmic radiation. The deflection of muonic particles present in the secondary cosmic radiation is the results of crossing of high atomic number materials (such as uranium or other fissile materials). This technique can provide a significant improvement compared to the traditional detection methods used so far that are based on X-ray scanners; this improvement concerns the enhanced capacity of identifying and locating illicit material, even in case that screens designed to mask the presence of this material are used. In this case the visualization plays a crucial role in obtaining tomographic images of a cargo container.
The datasets containing coordinates of the muon tracker planes are first uploaded to our gateway and filtered by using the Point of Closest Approach (POCA) algorithm to create a representation containing the scattering deflection of cosmic radiations. The result is then visualized using point rendering. Further processing is then applied based on user-defined thresholds, followed by conversion into data volumes using the deflection angle field distribution by employing the 3D Cloudin-Cell (CIC) smoothing algorithm. Finally, a tomography is performed for inspection.
Muon Portal and Main Workflow Steps
For this example we consider a simulation of particles in a large muon tracker consisting of 4 planes, 6 metres long and 3 metres wide, for the inspection of a container carrying high atomic number material. The illicit material is shaped with the string "CT".
Muon Workflow Example Visualization Steps
The data file containing the coordinates on the muon tracker planes is first uploaded to the gateway and filtered using the POCA (Point of Closest Approach) algorithm to obtain the VBT containing the scattering deflection of cosmic radiations; the steps of the POCA algorithm are shown in the previous figure. The resulting VBT can be visualized using a point viewer as shown in the top image of the next figure.
The steps of the POCA algorithm
The Filter portlet provides a rows filtering based on a given threshold at lower bound. The resulting VBT is then converted into a volume using the deflection angle field distribution, employing the 3D Cloud-in-Cell (CIC) smoothing algorithm, on an input defined regular mesh. The produced intermediate images are shown in steps 2 and 3 of Figure 10. Finally, a tomography can be performed on the produced volume VBT.
- E. Sciacca et al. Visivo science gateway: a collaborative environment for the astrophysics community. In 5th International Workshop on Science Gateways, IWSG 2013. CEUR Workshop Proceedings, 2013.
- Sciacca, E.; Bandieramonte, M.; Becciani, U.; Costa, A.; Krokos, M.; Massimino, P.; Petta, C.; Pistagna, C.; Riggi, S.; Vitello, F., "VisIVO Workflow-Oriented Science Gateway for Astrophysical Visualization," Parallel, Distributed and Network-Based Processing (PDP), 2013 21st Euromicro International Conference on , vol., no., pp.164,171, Feb. 27 2013-March 1 2013
- Becciani, Ugo and Sciacca, Eva and Costa, Alessandro and Massimino, Piero and Pistagna, Costantino and Riggi, Simone and Vitello, Fabio and Petta, Catia and Bandieramonte, Marilena and Krokos, Mel, Science gateway technologies for the astrophysics community, Concurrency and Computation: Practice and Experience, DOI: 10.1002/cpe.3255
The workflow can be accessed via VisIVO science gateway . The user submits the workflow by configuring the input data files and parameters through an easy-to-use portlet interface. The workflow has a modular architecture and its building blocks can be easily reused to build other workflows.