The goal of the MXA project is to allow the researcher to gather all the information and data that pertains to a particular experiment and store that information in a single location in an open format. Thus allowing the researcher to easily share data with thier peers for further analysis.
Main MXADataModel web site: http://mxa.web.cmu.edu/
Jackson, Michael, and Jeff P. Simmons, M. De Graef. MXA: a customizable HDF5-based data format for multi-dimensional data sets. Modelling and Simulation in Materials Science and Engineering Volume 18 Number 6, September 2010.
Too Many Files
While doing research many data files are usually created. Typically these files are stored in a mish-mash of folders scattered about a users computer system. Important information about the experiment may or may not follow the data. Losing this meta data may render the actual data useless to the researcher. Each of these files could be stored in different formats which can be either proprietary or opensource
Data Storage and HDF5
HDF5 is a scientific file format under ongoing development at UIUC. The HDF format was originally designed to store data being produced on High Performance Computing (HPC) systems. After a number of revisions to the HDF specification a complete rewrite was under taken to solve some of the limiting issues that had arisen during production use. The latest revisiion is version 5, or HDF5. This file format organizes data in a "Directed Graph" which in its simplest form can be used in a heirarchical fashion. Any type of data can be stored into the file in any organization that the researcher desires. In this way the HDF5 format is a highly flexible storage format in which to store vast amounts of data.
The concept of a "Data Model" is introduced in order to bring some consistancy to the layout of the data within an HDF5 file. The data model consists of 3 main parts and tries to follow generally accepted experimental methods.
1. Data Dimensions are the independent variables of a particular data set or experiment
2. Data Records are the the dependent variables of the experiment
3. Data Root is used to describe the location within the HDF5 file where the actual data resides
The data model is stored in the HDF5 file in a strict location and follows a specification that states how the information is stored. By using this type of system, exchange of MXA files between algorithms becomes easier and more straight forward. Note that the values that are written to the "Data Model" part of the HDF5 file only describe the experiment and the layout of the data within the HDF5 file. The actual data is stored in another location inside the HDF5 data file.
The "Data Root" is a value that holds the 'path' to the actual experimental data as it is stored within the HDF5 data file. The data is stored according to the heirarchy that is laid out in the Data Model. Using this approach, any piece of data can be quickly found either by a human being or by automated processes.
Data sets available for download
IN100 - This dataset consists of a series of sections through an IN100 sample, provided by Jack Schirra, of Pratt and Whitney in support of the DARPA AIM program. It was sectioned with a slice-and-view method with the Focused Ion Beam by Mike Uchic of AFRL. Area of each image is approx 30 x 30 microns, and spacing between consecutive images is 100 nm.
IN100 Tile Series 7000 Slice 0
Pearlite - Digitized versions of legacy pearlitic steal micrographs.
RoboMet - A beta-processed titanium alloy, courtesy of Dr. H. Fraser at The Ohio State University, acquired with a RoboMet automated serial sectioning instrument.
RoboMet Slice 68 Tile 04
MNML-3 - RoboMet.3D image stack of 3 phase Ni-Al-Epoxy on a nanoscale courtesy of US Air Force Research Labs. Data Collected under the supervision of Dr. J. Spowart. Data Release under US Air Force Public Affairs case number 88ABW-2009-5021. The complete data stack is 4 Tiles by 5 Tiles by 926 slices and totals about 24 GB in size. The data set linked here is a subset of that consisting of slices 769 to 780.
MNML-3_200x Slice 50 Tile 01
MNML-5 - RoboMet.3D image stack of 2 phase Ni-Epoxy on a nanoscale courtesy of US Air Force Research Labs. Data Collected under the supervision of Dr. J. Spowart. Data Release under US Air Force Public Affairs case number 88ABW-2009-5022. The complete data stack is 9 Tiles by 6 Tiles by 821 slices and totals about 50 GB in size. The data set linked here is a subset of that consisting of slices 100 to 110.
MNML-5_500x Slice 136 Tile 13