## 3 Proposed Method
### Design Knowledge Semantic Network  
#### 3.3.1 Overview  
The DKSN covers three dimensions of knowledge, including _literature_ knowledge (metadata, such as author, affiliations, keywords, title, citations, and contents), _artifact_ knowledge (the inheritance and composition relationship of design objects), _rationale_ knowledge (_issues, intents, pros/cons_, and _alternatives_), and the relationships between them. _Artifact_ is about design object knowledge, and _rationale_ is about design process knowledge. Both are described in the _literature_ in a specific writing style, as shown in Figure 3.  
Figure 3: Diagram of Design Knowledge Semantic Network.  
Literature dimension. The task of computational linguistics is to transform technical literature that is easy for humans to read into text data that can be easily interpreted by computers. The machine interprets the text data, tries to find and extracts the knowledge therein, and transforms it into a knowledge network that is suitable for the designer's fast understanding. Therefore, this study takes documentation as an important dimension for the construction of DKN. Through citations, co-inventors, co-authors, and others, the publicly available literature naturally constitutes a knowledge network.  
Artifact dimension. [PERSON] [67] defined _artifacts_ as being \"produced by art rather than by nature; not genuine or natural; affected; not pertaining to the essence of the matter\". _Artifacts_ are the material basis for the realization of design intent. They are about know-what. To put it simply, treating the _artifact_ as a product, using the superclass, class, subclass, property, and other elements for ontology modeling, all products in ODKN will form an open, hierarchical product data dictionary, which is also a knowledge network.  
Rationale dimension. A _rationale_ is a justification of the design decision, including the _issue_, _intent_, _pro_ and _cons_, and _alternatives_ of the _artifact_. _Alternatives_ are other _artifacts_. Design decisions are justified by comprehensively considering the _pro_ and _cons_ of solutions during the design argumentation. They are about know-why. Due to the fragmentation of rationale, rationale alone cannot form a knowledge network.  
**Definition 1**.: _DKSNnetwork. A Design Knowledge Semantic Network is a directed, node-edge-labeled knowledge graph. G = (C, P, R, A)._  
* Classes or Nodes (N). In this paper, entities, nodes, or classes are considered synonyms, which are expressed as \"(class)\".
* Properties (P). Related information about a class. For example, names, identifiers, authors, and other relevant information can be the property of a document; materials, geometric dimensions, and functional descriptions can be the properties of an artifact.
* Edges (E) or Relations. Edges represent the logical relationships between nodes or classes. They include generic relationships as defined in OWL or protege tools, such as IS-A; some specific DR relationships within the DKSN network, such as _Realize_, _Describe_, _hasIntent_, and _hasOpionion_ relations, are expressed in the form of directed arrows: -[relation]->.
* Axiom rules (A). Axiom Rules are expressed with the Semantic Web Rule Language (SWRL). SWRL is an expressive OWL-based rule language. SWRL allows for the definition of DKSN-specific rules that can be expressed in OWL concepts to provide more powerful deductive reasoning capabilities.