Templates

The information structure of ChemConnect representing the interaction between the domain knowledge and the actual use of the domain knowledge to build database objects can be thought as having three levels:

The Catalog object: This ontology object gives the basic structure of the object, i.e. which knowledge (ontology objects) should be given. This definition is not domain specific.
Domain Templates: The domain templates specify how some of the records in the catalog object should be filled. For example, attributes of devices, subsystems and sensors that describe a particular device or the set of parameters that make up an observation would be specified. This domain knowledge comes from case studies.
Database: The templates specify, for example, the attributes or parameters, but when the templates are used to, for example, characterize a device, then a database object is made and specific values for the attribute are filled in.

Templates within the ontology give a pattern or a generic description of domain objects. The templates themselves are ontology objects, but they contain information to further characterize domain objects. Templates answer the question, for example, how should one characterize a typical device. In the example below, the template for a heat flux burner will be shown.

One can think of templates the needed information to characterize an object and the database object itself is a particular example. For example, in characterizing a burner, the template would give as one of the describing attributes the diameter of the burner. It is implying that all burners have a diameter (the template), but particular burners could have particular diameter (the database value).

Example: Characterizing a Heat Flux Burner

The heat flux burner a device which is characterized by the SubSystemDescription catalog object which is used to characterize generic devices, subsystems, sensors and device components. The SubSystemDescription catalog object, other than the standard catalog object fields, has the following specialized fields:

To create a database object of this type, these objects should be filled in:

ObservationSpecification: The set of observations coming from the subsystem.
ParameterValue: A set of attributes that describe the subsystem (and differentiate this subsystem from others).
SystemSystemDescription: The set of subsystems making up this subsystem.

This is the generic subsystem description. The generic catalog object, described in the ontology, says that all sub systems have these quantities. These are general enough to specify a wide range of devices, subsystems, sensors and device components. It is the job of templates to give a more detailed specification, for example, which ParameterValue should be specified to describe the particular subsystem.

The task of the template is, through domain knowledge, give patterns (templates) on how to fill in these elements. The domain knowledge is captured in another ontology object which specifies these parts.

The device, the Heat Flux Burner, has a set of subsystems, observations and parameters. In the template specification of HeatFluxBurner (an ontology object), a set of 'attributes' are specified. Which parameters were deemed needed or appropriate were gleened from the literature and derived from researchers working in the domain. The catalog object specification said that a subsystem is described by a set of ParameterValues. The template ontology object HeatFluxBurner specifies that these parameters (attributes) should be used to characterize a typical heat flux burner. The ChemConnect uses this template information to set up the interface so these values can be supplied for a particular heat flux burner description that will be entered in the database.

This template is used to set up the user interface to input the actual values to characterize the particular Heat Flux Burner. Each attribute above corresponds to a user interface row for that particular value where the user can enter the property value. After the values are entered by the user, then the object is saved into the database. All database objects describing a heat flux burner have specific values of all these attributes. Having the same set of attributes for a object facilitates their comparison. The purpose of the template is to say that all objects of a given type should have these (common) properties.

Parameter Specificiation

Another template description is a parameter.

Concept: The chosen concept, out of the hierarchy of concepts, associated with the particular parameter
Purpose: The chosen purpose, out of the purpose concepts, associated with the parameter.
elementKind: This specifies whether the parameter is a fixed parameter or a dynamic parameter.
unitSystem: The unit class of the parameter, in the example is unit system LengthUnit.

The parameter template is used in two ways.

Specification: The specification, for example, the specifications of parameters that make up an observation, where the values are left open. A specification is, for example, defines a column of a matrix of values. All of the elements of the column have the properties of the specification.
Attribute: An attribute, for example as above, specifying the value (with units) of the object.

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