The main topic of the thesis is talking about the security services of x - pdm , the realization of the security scheme , and the automatic understanding for electronic circuit schematic drawings , which is the key technology of document management in x - pdm 本文的主要內(nèi)容涉及x - pdm系統(tǒng)的安全服務及其實現(xiàn)方案的設計,以及圖檔管理關(guān)鍵技術(shù)之電子電路原理圖自動輸入與理解系統(tǒng)的研究。