Represent increase/decrease opposed to absolute values

[lumi321]

Description of the issue

Not all values are depicting absolut values at a given point in time. Some values are depicting an increase of some parameter over a certain time span. How this notion can be represented in metadata depends on the structure of the data and the metadata.

Ideas of solution

1. add concepts that indicate increase/decrease and use them in combination with other concepts for "usual" annotation (related to the composed module discussion)
2. use a table-wide key in the metadata, e.g. subject, to indicate that all values in the table represent an increase or decrease
3. ask for an additional key in the metadata that indicates whether a value is absolut, shows an increase or a decrease
4. something else

Workflow checklist

• I am aware of the workflow for this repository

[stap-m]

Related to #1595 ?

@nelekoehler or @viktorwichern can you take a look at this issue?

[nelekoehler]

It seems to be related. In #1595 it's suggested to add processes heating and cooling, which would be used to describe the increase/decrease of thermal energy of a material entity. So maybe the suggested concepts of increase and decrease in this issue could be used for that too.

[nelekoehler]

Maybe Increase and decrease could each be introduced into the ontology as a process. (Increase: to become progressively greater and decrease: to become progressively less).
These concepts could then be used for heating and cooling, as it was questioned in #1595 , among others, by adding something like: has participant some increase or decrease and has unit some temperature unit as axioms). On the one hand, this is perhaps a bit more long-winded then using something like heating or cooling, on the other hand, increase and decrease can be used in a more versatile way (i.e. not only with temperature units and connected to thermal energy, but also with other units of measurements).

[nelekoehler]

In the following I would like to suggest some definitions:

Increase:

• A process of becoming larger, more numerous, more important, or more likely.

Decrease:

• A process of becoming smaller, less numerous, less important, or less likely.

I looked at different ontologies and these are the ones used in the NCI (a biomedical ontology) and I think it is general enough to be fitting for different uses.

Other ontologies like the INO, also have definitions for increase or decrease, but they use these terms also in the definition itself, so they seem circular, which isn’t ideal.

Possible Axiom:

• Has participant some entity

With reference to the other issue #1595 heating and cooling could be, as @stap-m already mentioned, something like: 
- heating EquivalentTo: increase and ('has energy input' some 'thermal energy') and ('has energy output' some 'thermal energy') and cooling resp.

[stap-m]

I am ok with the proposed definitions.

@l-emele @areleu @chrwm any opinion to the suggested structure with respect to heating etc.? For charging #1622 this could also be used. Probably there are more processes.

[l-emele]

I am fine with these proposals.

[nelekoehler]

Okay, if there aren't any other suggestions or concerns, I am going to implement it.