Content:

Dr. Fridsma gave us a lecture of ontology, information models and the semantic web. The web we used now is the syntactic web which is more about structures. It is a digital library, a database, a platform for multimedia and a naming scheme. However, for the syntactic web, computers do the presentation (easy) and people do the linking and interpreting (hard). The goal of semantic web is to be machine-readable and machine analysis, and make machines smarter and more useful. Though html and xml have given the annotation tags to the machine-read information, there are many things impossible for syntactic web, which need semantics to deal with.


Because even the same thing will have different concepts for different people, so ontology is used to specify the meanings of annotations. Considering the limitations of conventional enumeration, languages for ‘explicit specification’ are invented to represent the two components of ontology: names for important concepts in the domain and background knowledge on the domain. Dr. Fridsma put much emphasis on the RDF- resource description frameworks. RDF is a object oriented which is based on objects, types and relations. RDF data model provides the mechanism to express the semantics and RDF schema helps to build the relations. Also, RDF is too weak to describe resources in sufficient details, that is the reason for development of OWL language. The “layer cake” of OWL is much similar to the TCP/IP, but the relationship between layers is not clear.



In the class on Wednesday, continuing the machine learning topic, we learned the cluster-unsupervised learning. It is easy for me to understand clustering and its types because of less logic and the online demo and examples helped a lot. And I am sure that the student example will be useful for explanation of k-nearest neighbour and k-means. I know that the processes of machine learning are more complicated that what we are talking in the class. And the integration of semantic web and machine learning is the equation: Semantics + Web + AI= more useful web.


Posted by  Xiaoxiao