Page 115 - JOURNAL OF LIBRARY SCIENCE IN CHINA 2015 Vol. 41

114 Journal of Library Science in China, Vol. 7, 2015

For this situation, based on the network, “Organizing up” reorganizes historical knowledge by
fact relations, co-occurrence relations and statistical relations, and displays knowledge objects,
facts and all kinds of related relations in multiple dimensions such as time, class, and hierarchy,
which can then be used in many applications such as knowledge navigation, browsing, chronicle of
events, chronology, and so on.
Through “Mining down, Organizing up”, fine-grained historical knowledge can be mined from
text items, organized and associated to achieve knowledge visualization, retrieval, association,
reorganization, and so on.

2 Specific method of semantic representation and organization

Several key problems need to be solved in the method of “Mining down, Organizing up”, including
how to abstract the basic organization schema of the historical knowledge on contemporary China
in order to determine the basic types of knowledge objects and their associations; which core
knowledge objects should be determined as the basis of automatic identification; how to extract
facts about knowledge objects from texts; how to realize deeper-level organization.
To solve these problems, this paper proposes the specific method of semantic representation and
organization as follow.

2.1 Define the concept schema of contemporary Chinese historical ontology as the
foundation organization model

There are huge informative historical materials on contemporary China with rich and complex
details. It is necessary to make clear what need to be focused on and what historical details need
to be shown, namely a knowledge organization model should be firstly confirmed. Therefore, we
built a contemporary Chinese historical ontology to organize historical knowledge, using abstract
classes to represent the types of core knowledge objects, and properties to reveal the characteristics
of objects and their relationships. Based on the concept schema of the ontology, we outlined the
knowledge framework of the history on contemporary China to support concrete representation
and organization.
By referring to ontology construction methods such as Skeletal Methodology (Uschold &
King, 1995) and Seven Steps (Noy & McGuinness, 2015), we proposed the concept schema of
contemporary Chinese historical ontology with the help of historical experts. By analyzing related
text resources, we found that the track of history is mainly consisted of important historical events,
conferences, people, etc. Therefore, we firstly defined 15 classes in the historical ontology, such
as Event, Conference, Person, Institution, Document, Concept, and so on (see Figure 2). Then
we defined 20 datatype properties and 76 object properties according to the description of these
classes to model the properties and relationships of knowledge objects. For example, in Figure