GIS的底層架構在選區劃分之應用

Abstract

選區劃分近年來在台灣一直是備受關注的問題，由於選舉法規的修改以及行政區域的調整，選區必須重新調整，因此自動化的選區劃分方法也逐漸受到重視。過去的研究往往以不同的方法自動的劃分選區，而這類的方法常使用類似的功能進行選區劃分與評估。研究者彼此間缺乏一套可互享資源的標準或機制，往往導致新的研究者必須耗費甚多的時間來重新設計或開發這些類似的功能。\n本論文中，我們提出一套機制以及整合此套機制的系統架構，可以減少自動化劃分選區軟體的開發成本。我們結合地理資訊系統內部結構，淬取圖層中的線段，改良自動劃分選區所採用的單元，再利用線段在各圖層間的相位關係，建立新的相鄰定義與相鄰關係，從而能改善選區劃分的方法與劃分結果評估之效能。\n實作中，我們以所有台灣23個縣市的圖層來測試我們的機制，實驗結果顯示我們的機制可以有效的判斷選區邊界對選區形狀完整性造成的影響，同時，採用淬取之線段來計算，能大幅降低評估選區形狀所需之時間。

Electoral districting has received more attentions in Taiwan in recent years due to the change of electoral regulations or the change of the administrative districts. As a result, automatic electoral districting mechanism has also gotten more attentions gradually. Previous researches used various approaches in solving these problems and tend to adopt similar mechanisms in region districting or in results evaluation. The lack of standards or mechanisms in sharing the developing resources yields tremendous time wasting in rebuilding such functions.\n\nIn this thesis, we proposed a set of mechanisms as well as the system architecture that integrates these mechanisms. Using this system, one can reduce the costs in developing automatic electoral districting software. We also designed a system architecture that integrates these mechanisms and helps to reduce the maintenance costs. We extracted the arc properties from the coverage data layer in GIS to improve the basic unit used in the automatic electoral districting. We proposed a new concept of adjacency relations and used the topological relations in various data layers to construct these new adjacency relations. Using these new relations, one could improve the electoral districting developing processes as well as the efficiency of performance evaluations.\nWe used all twenty-three counties and cities of Taiwan to test our mechanisms. Experimental results shown that our mechanisms could determine the influences of districts’ boundaries to the districts’ shapes effectively. Moreover, using the extract arcs, one could reduce the time required in evaluating the districts’ shape dramatically.