# Roadmap Modeling and Assessment Approach for Defense Technology System of Systems
## 4 Illustrative Examples  
Two illustrative examples are demonstrated to validate the proposed modeling and assessment approaches. In the first case, the authors investigated the maritime security strategy and related combat system of systems. Based on the hierarchical decomposition structure of military requirements, the contribution rates of focal defense technologies were evaluated. Then, a dual-layer knowledge-flow network model was constructed using the patent documents belonging to the \"Coherent Light Generator (CLC)\" classification which are collected from the USPTO database and the related academic papers from Web of Science. Then, the node important in knowledge diffusion was computed in the second example. Maritime security is a highlighted component in the system of national security, which plays a key role in exploiting natural resources and maintaining trade routes. Through summarizing research achievements in the related literature [32; 33], the authors abstracted three focused objectives at the strategy level, including a fast response to potential invasions, patrolling in territorial water/airspaces, and maritime search and rescue, as outlined in Table 2.  
Based on the identified strategic requirements mentioned above, the related elements were decomposed layer by layer including seven military capabilities, 10 weapon systems, and nine defense technologies. Using the multi-view model framework in Section 3.1, the requirement mapping model was constructed; the outline information of the elements in each layer of the model are displayed in Table 3 and the interrelations among them are demonstrated in Figure 2.  
According to the assessment approach for the contribution rate in Section 3.3, the authors constructed the judgement matrices using the element mapping relations and computed the scores of relative importance with collected objective data and relevant expertise. Through updating the contribution rates layer by layer, the nondimensionalized values of focal defense technologies in satisfying military requirements were evaluated; they are demonstrated on the vertical axis of Figure 3. \begin{table}
\begin{tabular}{c c c} \hline \hline
**ID** & **Requirement Name** & **Outlines** \\ \hline ST-1 & Fast response to potential invasions & Intercepting, tracking, monitoring, and evicting the military objectives invading into the territorial water/airspaces \\ \hline ST-2 & Patrolling in territorial water/airspaces & Maintaining the normal operation of resource exploitation and commercial transportation in the target area \\ \hline ST-3 & Maritime search and rescue & Maintaining the risk monitoring and information communication, locating and rescuing persons, watercrafts, and aircrafts in distress \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Requirement elements at the strategy level. Figure 2: Requirement mapping model of defense technologies in the area of maritime security. The knowledge-flow network model consists of patents representing applied technologies and articles referring to basic scientific research achievements. First, the authors collected 21417 patent documents belonging to the CLC classification from USPTO database. The patent-layer network model was constructed through abstracting the citation information using text-mining tools. Then, the highlighted nodes of which the in-degree or out-degree are among the top 1% highest were selected. Third, the authors selected365 articles cited by the patents corresponding to the highlighted nodes and integrated the two kinds of elements to complete the dual-layer citation network. The network model is demonstrated in Figure 4, where the red nodes represent articles and blue ones indicate patents.