Re: [Asdf] Location information with SDF

[Christer Holmberg <[e-mail]>]

Hi Hyunjeong Lee,

 

>> Q1) What are the advantages compared to using sdfProperty?

> 

> Rather than having advantages, I think sdfProperty and sdfLocation have different characteristics.

> sdfProperty represents the property of sdfThing or sdfObject, and sdfLocation is an independent class

> such as sdfObject and can have sdfProperty.

 

Well, location can also be seen as a property, right?

 

Note that I am not objecting to your idea at this point, I am just trying to understand everything behind it :)

 

>> Q2) What about CHILDREN? For example, if you define sdfLocation for an sdfThing, does the location apply to

>> the children (sdfThings and/or sdfObjects)?

>> 

>> (As far as I remember, SDF does not define "inheritance" of properties etc.)

> 

> I think it can be called an inheritance or inclusion relationship.

> In the example of the conference room that I sent Nov. 8th, if we define the conference room as sdfThing and define the sdfLocation of this sdfThing,

> it means that the chairs, desks, etc. included in the conference room are within the same sdfLocation.

>> Q2-2) But, then you do assume there is inheritance of data :)

> That may be true about the sdfLocation.

 

I don’t think it is a good idea to define implicit inheritance for sdfLocation, while we don’t have it for sdfObject, sdfThing, sdfProperty, sdfAction, sdfEvent etc. 

 

For example, if I subscribe to an “conference room” sdfEvent, I am not automatically subscribing to the sdfEvents of the chairs, desks etc.

 

Also, in the conference room case, depending on how detailed your location information is the chairs, desks etc may not share the same location information.

 

But, perhaps you could use e.g., sdfRelation to explicitly indicate that the location information also applies to other sdfObjects/sdfThings.

 

Regards,

 

Christer

 

 



Regards,
Hyunjeong Lee

-----Original Message-----
From: "Christer Holmberg" [e-mail] <mailto:[e-mail]> 
To: "이현정" [e-mail] <mailto:[e-mail]> ; "Ari Keränen" [e-mail] <mailto:[e-mail]> ; "[e-mail] <mailto:[e-mail]> " [e-mail] <mailto:[e-mail]> ;
Cc:
Sent: 2023-11-15 (수) 19:26:42 (UTC+09:00)
Subject: RE: Re: [Asdf] Location information with SDF

Hi Hyunjeong Lee,

Q1) Just to clarify, are you suggesting to modify Option 2, and use sdfLocation instead of sdfObject (per Ari's notes)?

Exactly.

What are the advantages compared to using sdfProperty?

Rather than having advantages, I think sdfProperty and sdfLocation have different characteristics.
sdfProperty represents the property of sdfThing or sdfObject, and sdfLocation is an independent class such as sdfObject and can have sdfProperty.

Q2-1) What rule/definition is that based on?

(I assume you mean sdfThing "Humidimeter")

The rule is that the sdfLocation represents the location of the parent sdfThing or sdfObject.

Ok.

What about CHILDREN? For example, if you define sdfLocation for an sdfThing, does the location apply to the children (sdfThings and/or sdfObjects)?

(As far as I remember, SDF does not define "inheritance" of properties etc.)

I think it can be called an inheritance or inclusion relationship.
In the example of the conference room that I sent Nov. 8th, if we define the conference room as sdfThing and define the sdfLocation of this sdfThing,
it means that the chairs, desks, etc. included in the conference room are within the same sdfLocation.

Q2-2) Sure, but what if there is no other?
If nothing else, use the parent's address (which will likely have a larger range).

But, then you do assume there is inheritance of data :)

That may be true about the sdfLocation.

Regards,

Christer

-----Original Message-----
From: "Christer Holmberg" [e-mail] <mailto:[e-mail]> 
To: "이현정" [e-mail] <mailto:[e-mail]> ; "Ari Keränen" [e-mail] <mailto:[e-mail]> ; "[e-mail] <mailto:[e-mail]> " [e-mail] <mailto:[e-mail]> ;
Cc:
Sent: 2023-11-13 (월) 22:07:00 (UTC+09:00)
Subject: RE: Re: [Asdf] Location information with SDF

Hi Hyunjeong Lee,

Thank You for the reply! Please see inline.

Q1:

The Properties in sdfObject "AddressInformation" provide data (location
information) that applies to the "Humidimeter" sdfThing and the "Humidity"
sdfObject.

I think that concept is not part of base SDF - Properties only apply to the
sdfObject/sdfThing for which they have been defined.

(I know there are discussions about sdfRelations, and they are also used in
Option 2. However, they are only used to map the
location information to a dictionary - not to relate the information to
other sdfThings/sdfObjects in the SDF model.)

I suggested adopting the form of sdfLocation to indicate the position of
sdfThing or sdfObject.
This means that AddressInformation in Option2 should be replaced by
sdfLocation.

Just to clarify, are you suggesting to modify Option 2, and use sdfLocation
instead of sdfObject (per Ari's notes)?

Exactly.

Q2:

Related to Q1, the location Properties in sdfObject "AddressInformation"
apply to "Humidimeter" sdfThing. But, assume the following structure:

                 sdfThing "WeatherStation"
                                 |
                                 |
                  sdfThing "Humidimeter"
                                  |
                                  |
   -----------------------------------------------------
    | 

|
sdfObject "Humidity" sdfThing
"Foo"
sdfObject "AddressInformation" |

|

sdfObject "Bar"

Does the location information also apply to "WeatherStation" sdfThing,
and/or "Foo" sdfThing (and the "Bar" sdfObject)?

In the structure above, the sdfObject "AddressInformation" (sdfLocation
"PostalAddress" in my suggestion) applies to the sdfObject "Humidimeter."

What rule/definition is that based on?

(I assume you mean sdfThing "Humidimeter")

The rule is that the sdfLocation represents the location of the parent sdfThing or sdfObject.

Another sdfLocation "PostalAddress" can be defined if a more detailed
address for sdfThing "Foo" or sdfObject "Bar" is required as shown in the
structure below .

Sure, but what if there is no other?

If nothing else, use the parent's address (which will likely have a larger range).

In order to precisely depict the location of an object indoors, sdfLocation
"GPS & relative location" combined with a GPS and a relative location may be
used.

Yes. But, if you define sdfLocation somewhere, it needs to be clear what the
scope is. Which sdfThings/sdfObjects does it apply to.

Applies to the parent sdfThings or sdfObjects as in the answer above.

                 sdfThing "WeatherStation"
                                    |
                                    |
                 sdfThing "Humidimeter"
                                    |
                                    |
    ------------------------------------------------------------------------------------------------
    | 

| |
sdfObject "Humidity" sdfLocation "GPS &
relative location" sdfThing "Foo"

|

                                     ----------------------------------

| |

sdfObject "Bar" sdfLocation "GPS & relative location"

|

sdfLocation "GPS & relative location"

Q3:

Since (based on base SDF) the only technical difference between sdfThing
and sdfObject is that sdfThing can contain other sdfThings and
sdfObjects, does option 2 allow me to define sdfThing "AddressInformation"?

I think option 2 is most appropriate for expressing the location of
sdfThings and sdfObjects, if "AddressInformation" is changed as sdfLocation.

Ok. So, you are suggestion to modify Option 2, and use sdfLocation instead of
sdfObject?

Exactly!

Regards,

Christer


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