I'm creating an ontology using protege05 and I have a question in regard to property restrictions. What I've understood from the protege tutorial is that when we assign a property to a class using restrictions, it means that this property is necessary for defining that class.
for example, suppose i have classes "Orthodox Church" and "Sanctuary" and a property "hasPart and i want to say that "an Orthodox Church hasPart Sanctuary".
If I use existential restriction apparently it will mean that "having Sanctuary" is necessary for a building to be an Orthodox Church or if a building is an Orthodox Church it must ALWAYS have a Sanctuary.(but it's not always correct).
so my question is that how should insert this property without it being necessary for defining my class? in other words, how can i say that this property is SOMETIMES correct for my class but not ALWAYS?
Thanks
You want to use Orthodox Church as domain for your property - so, when used, you will infer the building is a church. It won't stop you from creating churches without sanctuaries.
Without changing the domain, you could create a class with 'some hasPart Sanctuary' as a subclass of 'Orthodox Church' - a sufficient but not necessary condition.
Related
I am new to schema.org. Currently i am trying to use it as our internal data model for imports as it offers a good "common ground" for all source systems.
The Hotel schema (https://schema.org/Hotel) offers a "photo" (singular) property, it inherits from Place. It used to have a "photos" (plural) property in the past.
When using schema.org for markup, this would not matter, as i can just mark up multiple elements as "photo".
However, when using it as a data class, how should i model it?
Should i just make it an array of Photograph?
If yes, does schema.org actually assume on ANY property that it may be multiple (amenityFeature, availableLanguage, etc. suspiciously look like that)?
Does that mean, i have to actually model every property as an array?
After some additional research i have to assume schema.org is not meant as a full data model. It is mostly about providing a common vocabulary and a hierarchy of information. Its primary use case seems to be markup, so types definitions are very vague since they have to work on content that is actually meant to be presented to a user. So i will have to specify my own schema and let my decisions and my naming be guided by schema.org.
I am beginner to spring aop and i am going through spring aop documentation to understand the concepts but failed to understand 'target object'.
the documentation says target object is the "object being advised by one or more aspects. Also referred to as the advised object".
what is the meaning of being advised by one or more aspects here? can anyone explain me what is target object in Lyman terms as i am still a beginner.
For a simple explanation of some basic AOP terms please refer to my other answer. Please read that one first before continuing to read here.
So the target object is the (Java or Spring) component to which you want to add new behaviour, usually a cross-cutting concern, i.e. some behaviour that is to be applied to many classes in your code base.
An aspect is a class in which you implement that cross-cutting concern and also determine where and how to apply it. The where is defined by a pointcut, some kind of search expression finding the relevant parts of your code base to apply the behaviour to. The how is implemented in an aspect method called an advice.
So when we say that an aspect advises an object, it means that it adds (cross-cutting) behaviour to it without changing the class itself.
In Spring AOP this is mostly method interception, i.e. doing something before or after a method executes.
In the more powerful AspectJ you can also intercept changes of member variables and constructor execution. Furthermore you can change the class structure itself by adding new members or methods or making the target class implement an interface etc.
Is it possible to define multiple targets like below:
#Before(value = "com.test.createUpdateDeletePointCut() && (target(com.testlab.A) || target(com.testlab.B))")
While developing a custom machine learning model for the extraction of information on CVs using WKS, we started to wonder if the usage of the negative mention class feature for anottation only has effect on the model if the mention has a relation indicated with another one, the question arises because one can change the mention class from specific (the default class asigned on a first annotation task) to negative without the need of creating a relation, but we don't know if this way of using the negative mention class is useful at all.
We already know that the ML model learns from positive and negative examples (leaving a mention without annotation) will the use of the negative mention class feature improve the performance of the model further? we ask this because, clearly we don't know how WKS works in detail under the hood.
as you know, below answer was posted in the Communities Forum.
Negative mention class can be used to annotate a mention of a lack of
something. For example, "there is no police presence in the region"
could have "police" annotated with entity type ORGANIZATION but
mention class NEG. Another option however is not to use NEG and
instead make one or more entity types for wording indicative of
negation, doubt, or anything else other than certainty, and a relation
type for connecting them to what they pertain to. So could have
no/NEGATION appliesTo police/ORGANIZATION or some such.
For example, for Book and Author classes, I can have authorOf relation, and or hasAuthor relation. For Student and Course classes, I can have courseOf and hasCourse relations between the two.
It seems redundant to always create relations in two directions. Is there any guideline or principle to deal with situation?
I'm not aware of any recommendation to always explicitly provide the inverse property.
There are at least two use cases for inverse properties:
The need to reference the inverse property, let's call it "IP",
internally in the ontology.
We may need to state that another property is disjoint with IP. Or that another property is equivalent to IP. Now, we provide IP to allow that statement. Another very trivial example is the desire to keep a comment in the right place. You may define IP just to place a rdfs:comment on it.
The need to externally reference the inverse property.
An example is: Our application assigns translations of natural languages to ObjectProperties. In case of the famous Protege Pizza Ontology, we translate "hasTopping" to strings like "en:has topping". We also want to express "en:is the topping of" in a natural language. (Our application semantics needs it.) That's a reason to create the inverse property "isToppingOf": To have an instance, respective an URI, our translations can refer to.
I'm having difficulties understanding when to use object properties and when to use data properties. I've read the definitions, but yet I'm having issues using them in a practical setting.
It would be of much help if anyone could correct the following example.
Let's say I'm making a Wine ontology, with some subclasses redWine, whiteWin, sparklingWine and so on. How will I then manage the properties for example goesWithFoodType, fromCountry and hasGrapeType? All in which have subproperties down the hierachy. Will all of these be data properties with the domain Wine and ranges xsd:string datatype?
If the things stated above is correct, would I have any use from object properties in my ontology?
Thanks.