April 11, 2019 Presentation Open Access

Main Introduction to the CHADA concept and case studies

Marco Sebastiani; Costas Charitidis; Elias P. Koumoulos

We present here a novel approach for the definition of terminology, classification and metadata for materials characterization methods, where the main purpose is to arrive to a standard structure (that we will call CHADA) for representing materials characterization data.

The first step towards this goal is the definition of the terminology associated to materials’ characterization methods. We propose that only four types of concepts are used for the classifications of the different steps of an entire characterisation workflow (which can be simply called “characterisation”):

1. Sample (or “user case”), which represents volume of probed material, and the information on the surrounding environment, which interacts with the probe and generate a detectable (measurable) signal(information);
2. Method, which represents the process(or the sequence of processes) by which the metrological chain is defined; within a single method, the following fundamental elements are identified : user, probe, signal, detector, noise;
3. Raw data, is the set of data that is given directly as output from the metrological chain, usually expressed as a function of time;
4. Data processing, which represents any process (or sequence of processes) by which thedata are analyzed to arrive to the final shape.

By using this simplified approach, a generic characterization method can be documented by the schemes reported in the presentation, which can be used for the construction of the metadata structure of any generic material’s characterisation process.

In those scheme, we also define the fundamental vocabulary that describes the main elements of a characterisation experiment, which could be further refined for any specific technique. 

Since all standardized characterization methodologies consists, in practice, of a well-defined sequence of items and actions, the same approach can be used to develop a generic workflow program.  This scheme is also based on a similar concept developed within the European Materials Modelling Council (MODA, https://emmc.info/moda/), where the data from a generic model are represented according to the representations of User Case, Model, raw outputs and processed outputs.