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pl:miw:piw08_hekateonto [2008/05/21 22:19] ikaf |
pl:miw:piw08_hekateonto [2008/07/03 12:54] ikaf zaczelam nie skonczylam czytac opis xtt |
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| - | ====== Opis ====== | ||
| - | Weronika Furmańska <ikaf@student.agh.edu.pl> | ||
| - | Porównać i omówić metody reprezentowania atrybutów w językach: | ||
| - | |||
| - | * RDF | ||
| - | * OWL | ||
| - | * RIF | ||
| - | * R2ML | ||
| - | * [[http://ruleml.org/|RuleML]] | ||
| - | * [[wp>Semantic Web Rule Language]] [[http://www.w3.org/Submission/SWRL/]] | ||
| - | |||
| - | oraz metody reprezentowania reguł w: | ||
| - | * RIF | ||
| - | * R2ML | ||
| - | * RuleML | ||
| - | * [[http://oxygen.informatik.tu-cottbus.de/rewerse-i1/?q=ERDF|ERDF]] | ||
| - | |||
| - | co to jest [[wp>datalog]]... | ||
| - | |||
| - | business rules orchestration | ||
| - | |||
| - | tools: | ||
| - | http://sweetrules.projects.semwebcentral.org/ | ||
| - | |||
| - | people | ||
| - | http://www.mit.edu/~bgrosof/ | ||
| - | |||
| - | concepts: | ||
| - | http://en.wikipedia.org/wiki/Description_Logics | ||
| - | |||
| - | |||
| - | ====== Spotkania ====== | ||
| - | * Jaki poziom szczegółowości projektu? Na próbę fragment o RDF - czy może być tak? | ||
| - | * Moje podejście - bardziej odpowiedź na pytania postawione w temacie, bez wnikania w szczegóły techniczne - słuszne? | ||
| - | |||
| - | |||
| - | ====== Projekt ====== | ||
| - | |||
| - | Draft... | ||
| - | |||
| - | |||
| - | ===== Part 1. Attributes representation in different markup languages ===== | ||
| - | |||
| - | ==== To start with... ==== | ||
| - | While talking about attribute-based languages we can recognize the following types of logic: | ||
| - | * AAL – Attributive Logic, i.e. attributive logic with atomic values of attributes only | ||
| - | * SAL – Set Attributive Logic, i.e. attributive logic with set values of attributes | ||
| - | * VAAL – Variable Atomic Attributive Logic, i.e.attributive logic with atomic values of attributes incorporating variables | ||
| - | * VSAL - Variable Set Attributive Logic, i.e.attributive logic with set values of attributes incorporating variables | ||
| - | |||
| - | === The alphabet and the crucial question:What is an attribute? === | ||
| - | Let there be the following, pairwise disjoint :-) sets of symbols: | ||
| - | * O – a set of object name symbols | ||
| - | * A – a set of attribute names | ||
| - | * D – a set of attribute values names (the domains) | ||
| - | * V – a set of variable symbols (variables) | ||
| - | |||
| - | If the set of attributes is finite and given as \\ | ||
| - | {{:pl:miw:atrybuty.png|:pl:miw:atrybuty.png}} \\ | ||
| - | then \\ | ||
| - | {{:pl:miw:domain.png|:pl:miw:domain.png}}, \\ | ||
| - | where D<sub>i</sub> is the domain of attribute A<sub>i</sub> , i=1, 2, ...,n. \\ | ||
| - | |||
| - | |||
| - | __Attributes in AAL and VAAL__ \\ | ||
| - | An attribute Ai is a function (or partial function) of the form:\\ | ||
| - | {{:pl:miw:atrybut-def.png|:pl:miw:atrybut-def.png}}\\ | ||
| - | An attribute can be a partial function, since not all the attributes must be defined for all the objects.\\ \\ | ||
| - | __Generalized attributes in SAL and VSAL__ \\ | ||
| - | A generalized attribute Ai is a function (or partial function) of the form\\ | ||
| - | {{:pl:miw:atrybut-def2.png|:pl:miw:atrybut-def2.png}}\\ | ||
| - | |||
| - | ==== RDF - Resource Description Framework ==== | ||
| - | === Basic information === | ||
| - | - RDF identifies things using Web identifiers (URIs) | ||
| - | - RDF is written in XML. The language is called RDF/XML. | ||
| - | - The main elements of RDF are the root element, <RDF>, and the <Description> element, which identifies a resource. | ||
| - | - <rdf:RDF> is the root element of an RDF document. It defines the XML document to be an RDF document. It also contains a reference to the RDF namespace. <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" | ||
| - | - The <rdf:Description> element identifies a resource with the rdf:about attribute. This element contains elements that describe the resource. | ||
| - | |||
| - | === Attributes representation === | ||
| - | |||
| - | "RDF is based on the idea that the things being described have properties which have values, and that resources can be described by making statements that specify those properties and values. RDF uses a particular terminology for talking about the various parts of statements." (W3C RDF Primer) | ||
| - | **Attributes are represented in RDF in a form of RDF Triples (subject, predicate, object) where subject denote the resource being described, predicate indicate the name of the attribute and object points to the attribute (predicate) value.** RDF statements (triples) consist of subject, predicate and object which all are identified by URIs. | ||
| - | |||
| - | ^ Part of an RDF triple ^ Can be ^ | ||
| - | | Subject | URI, blank node | | ||
| - | | Predicate | URI | | ||
| - | | Object | URI, literal (constant values, plain or typed), blank node | | ||
| - | |||
| - | \\ | ||
| - | |||
| - | **RDF uses VSAL**\\ | ||
| - | * variables can be used (blank nodes) http://www.w3.org/TR/rdf-primer/#structuredproperties | ||
| - | http://www.w3.org/TR/rdf-concepts/#dfn-blank-node | ||
| - | * sets of attributes cannot be defined in a single RDF triple, because attributes in RDF are represented as binary predicates only. However, it is possible to do that using RDF Container Elements (<rdf:Bag> and <rdf:Seq>) or RDF Collections. To define sets of attributes we create a new resource (which may either be a blank node or a resource with a URIref). The resource is given an rdf:type property whose value is one of the predefined resources rdf:Bag, rdf:Seq, or rdf:Alt . Then the members of the container can be described by defining a container membership property for each member with the container resource as its subject and the member as its object. | ||
| - | http://www.w3.org/TR/rdf-primer/#containers | ||
| - | |||
| - | |||
| - | === RDF/XML notation === | ||
| - | Triples of the Data Model (an example from W3Schools.): | ||
| - | ^ Subject ^ Predicate ^ Object ^ | ||
| - | | http://www.w3schools.com/RDF | http://www.recshop.fake/siteinfo#author | "Jan Egil Refsnes" | | ||
| - | | http://www.w3schools.com/RDF | http://www.recshop.fake/siteinfo#homepage | "http://www.w3schools.com" | | ||
| - | |||
| - | To avoid using URI all around we use namespaces which we define as follows: xmlns:si="http://www.recshop.fake/siteinfo#" \\ | ||
| - | In RDF/XML attributes (properties of subjects) can be defined in three ways | ||
| - | * Properties as XML elements | ||
| - | <code xml> | ||
| - | <?xml version="1.0"?> | ||
| - | |||
| - | <rdf:RDF | ||
| - | xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" <!-- rdf namespace --> | ||
| - | xmlns:si="http://www.recshop.fake/siteinfo#"><!-- other namespace (eg. Our own website's)> | ||
| - | <rdf:Description rdf:about="http://www.w3schools.com/RDF"> <!-- subject identifed with a resource by rdf:about attribute --> | ||
| - | <si:author>Jan Egil Refsnes</si:author> <!-- property and its value --> | ||
| - | <si:homepage>http://www.w3schools.com</si:homepage> <!-- another property and its value --> | ||
| - | </rdf:Description> | ||
| - | </rdf:RDF> | ||
| - | </code> | ||
| - | |||
| - | When you parse the example above with a RDF Validator, the result will look something like [[http://w3schools.com/rdf/RDFvalidationresult.htm|this]] | ||
| - | |||
| - | * Properties as attributes | ||
| - | |||
| - | * Properties as resources | ||
| - | |||
| - | (Z jakichś powodów nie mogę wkleić kodu - wyskakuje błąd o niezaimplementowanej funkcji POST...) --- //[[ikaf@student.agh.edu.pl|Weronika Furmańska]] 2008/05/21 18:31// | ||
| - | |||
| - | ====== Sprawozdanie ====== | ||
| - | |||
| - | |||
| - | ====== Materiały ====== | ||
| - | http://w3schools.com/rdf/default.asp\\ | ||
| - | http://www.w3.org/TR/rdf-primer\\ | ||
| - | http://www.ninebynine.org/RDFNotes/RDFFactsAndRules.html#xtocid-7\\ | ||
| - | [[http://gigapedia.org/items/51325/logical-foundations-for-rule-based-systems--studies-in-computational-intelligence---studies-in-computational-intelligence-|A.Ligęza - Logical Foundations for Rule-Based Systems]] 8-)\\ | ||
