With the development of computer 3d graphics technology , designers can express their intensions more directly a nd thoroughly by 3d body models . advanced cad tasks such as checkage of assembly and interference , the analysis by fem and analysis of movements etc . may be carried on based on 3d models 隨著計算機三維圖形學技術(shù)的發(fā)展,建立的實體模型能夠更直觀、全面地反映設計意圖,并且在此基礎上還可以進行裝配、干涉檢查、有限元分析、運動分析等高級計算機輔助設計工作。
The article put forward a grading control based on object technology over the permissions of msql system . the method divides the permissions of the whole msql into three grades including system grade , database grade and table grade . it encapsulates each grade permission into a class and designs a flexible algorithm , which is based on the calculation of bits and is for the assignment and checkage of permissions 本文提出了基于對象的數(shù)據(jù)庫權(quán)限的分級控制,即將整個msql系統(tǒng)的權(quán)限分為三級:系統(tǒng)級、數(shù)據(jù)庫級和數(shù)據(jù)表級,并分別用一個對象類包裝:并在此基礎上,設計了一種基于二進制位運算的、靈活的權(quán)限分配與檢查算法。