Ticket #38 (accepted task)

Opened 10 years ago

Last modified 9 years ago

Computation Model

Reported by: sventour Owned by: lawrence
Priority: major Milestone: V3.5 UML Final
Component: UML Information Model Version: V3.5
Keywords: Cc:

Description

First Cut of the Model

Within MOLES, a computation is a process step which involves only numerical computations to provide a result, without interacting with the feature of interest– in contrast with acquisition.

A first cut of the computation model following ISO 19115-2 and the  MO_Acquisition model is  here - ingnore the stereotype <<voidable>> at the moment.
where :
MO_Computation
--Definition--
A process which involves only numerical computation.

--Description--
NOTE 1 It may begin with one or more source data objects (themselves observations), but it may begin ab initio (no inputs) ; description of these source data objects is provided by MO_Source.
It is executed by a responsible_party and ends up with a result.

NOTE 2 Description of the computation result is provided by the MO_Source.

NOTE 3 The computation does not interact with the feature of interest (by definition).

MO_ComputationInstruction
--Definition--
Information about the instructions ( e.g. software, mathematical expressions ) where their execution provides a numerical result.

MO_ComputationPlatform
--Definition--
Computation Platform is the identfiable object on which a computation process step is executed.

--Description--
NOTE A Computation Platform consists of a machine and one or more compilers.

MO_Execution
--Definition--
Execution of a software or a set of instructions ( e.g. mathematical expressions) in order to get a numerical result.

Discussion : No Use of MO_Execution
The corresponding class of MO_Execution in the Acquisition model is MO_Operation. The question is if we really need the class MO_Execution.
I believe MO_Execution is not needed for the following reasons.

1) In an Acquisition the MO_Operation represents the way the acquisition instruments and platforms were deployed e.g. I operated the thermometer taking measurements every 6 hours.
In a Computation this action is defined by the software ( MO_ComputationInstruction) anyway. MO_Execution is simply the run of the software.

2)The definition of LE_ProcessStep is :
Information about an event or transformation in the life of the dataset including details of the algorithm and software used for processing

This definition I think describes perfectly a computation step and not the execution of the software – pressing of the button ( MO_Execution is a specialisation of LE_ProcessStep).


3)The structure of the model, as it is, because of the aggregation LE_ProcessStep – LE_Processing indicates :
MO_Execution is included in MO_Computation
MO_ComputationInstruction has the role processingInformation with respect to MO_Execution

MO_ComputationInstruction has the role instruction with respect to MO_Computation

So MO_Computation includes the piece of information MO_ComputationInstruction twice.

4)MO_Process can be an aggregation of computation steps. So a version of this model even without the class MO_Execution can support ensables ( e.g. run of the software more than one times with different configuration).

Therefore a proposed simplified version is  this.

Next Steps
Mapping with METAFOR ( almost done)
Attributes (using Use Cases)

Change History

comment:1 Changed 10 years ago by lawrence

  • Owner changed from sventour to lawrence
  • Status changed from new to assigned

Discussed today, but we need to think about it some more. It's not obvious that we have the right concepts (with mappings to metafor).

comment:2 Changed 10 years ago by lawrence

  • Status changed from assigned to accepted

comment:3 Changed 9 years ago by lawrence

  • Version changed from V3.4 to V3.5
  • Milestone set to V3.X Next Release

comment:4 Changed 9 years ago by lawrence

This will track the metafor V2  candidate model

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