主路徑分析（Main Path Analysis,MPA）是一種專利引用網路的分析方法。本研究之目的在於比較域內及跨域專利引用網路產出的主路徑的差異，特別是以結合BC（Backward Citation）的跨域、結合FC（Forward Citation）的跨域、結合BC+FC的跨域、以及域內等網路在專利主路徑上的各項比較，研究這些主路徑差異是否顯著。本研究選擇以臉部影像辨識之身分認證為實證研究案例，統計該技術領域之專利申請、專利申請人、以及專利分類號的件數，在2017年均達到成長的高峰。在主路徑產出上，計算網路連結權重，是採用節點考慮比較完整的SPNP方法。主路徑搜尋則以可產出最具代表性的一條主路徑的整體搜尋（Global Search）及可產出數條主路徑的關鍵搜尋（Key-Route Search）分別比較。歸納實證研究，比較結果如下：1.跨域與域內網路的專利主路徑相同件數不多，主要原因是域內與跨域在網路建立時的影響；2.BC+FC跨域專利主路徑件數＞域內專利主路徑件數，表示BC+FC跨域專利主路徑在知識或技術的演進過程中，可以看到更多技術變化，有助於專利的引用分析；3.域內專利主路徑，只會看到檢索結果﹙技術領域﹚內全部技術特徵同時的變化，則跨域專利主路徑，可以看到技術領域內全部技術特徵同時的變化或局部技術特徵的變化；4.觀察域內與跨域整體搜尋主路徑，在技術或知識傳遞過程，都是以臉部或圖像辨識技術開始，由於域內整體搜尋主路徑較短，只有看到技術傳遞到手機產業，而以跨域整體搜尋主路徑觀察，則廣泛應用於手機、行動裝置、網路資源存取及零售通路等產業。總結兩種網路的優缺點，提出研究結論，域內網路主路徑分析，適合技術領域的快速觀察，跨域網路主路徑分析，適合技術領域的深入研究。

Main Path Analysis (MPA) is a method for analyzing patent citation networks. The purpose of this study is to compare the differences in the main paths produced by intra-domain and cross-domain patent citation networks, especially the cross-domain combined with BC (Backward Citation), the cross-domain combined with FC (Forward Citation), and the combined BC+FC the comparison between the cross-domain and intra-domain networks on the patent main path is to study whether the differences between these main paths are significant. This research selects the identity authentication of facial image recognition as an empirical research case, and counts the number of patent applications, patent applicants, and patent classification numbers in this technical field, all of which have reached a peak of growth in 2017. In the main path output, the calculation of the network connection weight is based on the SPNP method with a relatively complete node consideration. The main route search is compared with the global search that can produce the most representative main route and the key search that can produce several main routes. Summarizing the empirical research, the comparison results are as follows: 1. The number of patent main paths of the cross-domain and intra-domain networks is the same, mainly due to the influence of intra-domain and cross-domain network establishment; 2. BC+FC cross-domain The number of patent main path pieces > the number of patent main path pieces in the domain, indicating that in the process of knowledge or technology evolution, more technological changes can be seen in the BC+FC cross-domain patent main path, which is helpful for patent citation analysis; 3. The main path of intra-domain patents can only see the simultaneous changes of all technical features in the search result (technical field), while the main path of cross-domain patents can see the simultaneous changes of all technical features or partial technical features in the technical field; 4. Observe the main path of the overall search within the domain and across the domain. In the process of technology or knowledge transfer, it all starts with face or image recognition technology. Since the global search within the domain is short, only the technology is transferred to the mobile phone industry. , and the cross-domain global search for the main path observation is widely used in industries such as mobile phones, mobile devices, network resource access, and retail channels. Summarize the advantages and disadvantages of the two networks, put forward research conclusions, the main path analysis of the intra-domain network is suitable for quick observation in the technical field, and the main path analysis of the cross-domain network is suitable for in-depth research in the technical field.

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