[Rdfapi-php-interest] RDQL Query

hi, i am new to RAP API. At the moment, i have developed my OWL model
in protege 3.1 beta. and managed to load the model by using RAP. but,
when i tried to query to return a student's full name, it always says
'no match'. This is what I wrote for the query :

$rdql_query=3D'select ?fullname
where(?x, <person:lastName>,"Rusli")
(?x,<person:name>,?fullname)
using owl for <http://www.w3.org/2002/07/owl#>
person for <http://ebiquity.umbc.edu/v2.1/ontology/person.owl#>
';

$res=3D$model->rdqlQuery($rdql_query);
RdqlEngine::writeQueryResultAsHtmlTable($res);

and this is my OWL model:

<?xml version=3D"1.0"?>
<rdf:RDF
    xmlns:assoc=3D"http://ebiquity.umbc.edu/v2.1/ontology/association.owl#"
    xmlns:research=3D"http://ebiquity.umbc.edu/v2.1/ontology/research.owl#"
    xmlns:rdf=3D"http://www.w3.org/1999/02/22-rdf-syntax-ns#"
    xmlns:xsd=3D"http://www.w3.org/2001/XMLSchema#"
    xmlns:pub=3D"http://ebiquity.umbc.edu/v2.1/ontology/publication.owl#"
    xmlns:rdfs=3D"http://www.w3.org/2000/01/rdf-schema#"
    xmlns:owl=3D"http://www.w3.org/2002/07/owl#"
    xmlns=3D"http://ebiquity.umbc.edu/v2.1/ontology/project.owl#"
    xmlns:contact=3D"http://ebiquity.umbc.edu/v2.1/ontology/contact.owl#"
    xmlns:cc=3D"http://web.resource.org/cc/#"
    xmlns:person=3D"http://ebiquity.umbc.edu/v2.1/ontology/person.owl#"
  xml:base=3D"http://ebiquity.umbc.edu/v2.1/ontology/project.owl" >
  <rdf:Description rdf:about=3D"">
    <owl:imports
rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/contact.owl#"/>
    <owl:imports rdf:resource=3D"#"/>
    <rdf:type rdf:resource=3D"http://www.w3.org/2002/07/owl#Ontology"/>
    <owl:imports
rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/research.owl#"/>
    <owl:imports
rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/person.owl#"/>
    <owl:imports
rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/publication.owl#"/>
    <owl:imports
rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/association.owl#"/>
  </rdf:Description>
  <rdf:Description rdf:about=3D"#RudyRusli">
    <person:name
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Rudy
Rusli</person:name>
    <person:biography
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Rudy Rusli is a
master student at Curtin Uni</person:biography>
    <person:firstName
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Rudy</person:first=
Name>
    <person:lastName
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Rusli</person:last=
Name>
    <rdf:type rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/person=
.owl#MSStudent"/>
  </rdf:Description>
  <rdf:Description rdf:about=3D"#DedySyamsuar">
    <person:lastName
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Syamsuar</person:l=
astName>
    <person:firstName
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Dedy</person:first=
Name>
    <rdf:type rdf:resource=3D"http://ebiquity.umbc.edu/v2.1/ontology/person=
.owl#MSStudent"/>
    <person:name
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Dedy
Syamsuar</person:name>
    <person:biography
rdf:datatype=3D"http://www.w3.org/2001/XMLSchema#string">Dedi is a
student at curtin uni</person:biography>
  </rdf:Description>
</rdf:RDF>

<!-- Created with Protege (with OWL Plugin 2.0 beta, Build 245)=20
http://protege.stanford.edu -->

can somebody help me in correcting my query ?

thank you
rudy rusli