major operation data system 中文意思是什麼
major operation data system
解釋
主操作數據系統-
Firstly, pci local bus technology is generally introduced, including the major features of pci local bus, the concepts of basic signals, pci local bus operation and configuration space of pci device in the thesis. subsequently, the correlative technology and choice of the design of the system are summarized. the chip ( ep1k30qc208 - 3 ) in this design and mode of data transmission are introduced
本論文在硬體方面，首先，介紹了pci總線的基本操作與一些基本概念，包括pci總線信號定義和pci總線的讀寫操作以及仲裁操作;接著，介紹了pci總線介面設計和數據傳輸方式以及設計所用altera公司的acex1k系列中的ep1k30qc208 - 3晶元;最後，完成了使用低廉的晶元實現pci總線介面設計。 -
The main research contents are as follovvs : after the analyzing of the process of making train diagram, according with its character, and take into account the trend of innovation, chooses the total solution based on the b / s architecture, 3 - tier operation distributed and 2 - tier data distributed to separate the data from operation and simplify the development and maintenance ; the e - r data model that is accord with the 3nf criterion is designed after analyzing the data structure of the train diagram system. emphasis on the permission security of the distributed system, take the view schema, coupled with the login authentication and permissions validation, to ensure the data accessing domination, and take the synchronization, error control, and restore capability to advance the data security ; on the basis of b / s solution architecture, after comparing the existing transportation technologies, b - isdn and adsl is selected as the major solution architecture based on the package - svvitched networks. furthermore, error control, firewall, and encryption techniques are introduced to prevent the hacker attack and ensure the networks safety
論文的主要研究內容包括：對目前我國列車運行圖管理體制和編制流程進行詳細分析，根據其「幾上幾下」的特點，並結合未來「網運分離」體制改革的變化預測，選擇採用與之相適應的基於b s體系架構、三層業務分佈、二層數據分佈的整體方案，實現業務與數據的分離，降低開發與應用過程的復雜度和總體成本；對列車運行圖系統的數據信息進行分析，設計符合3nf規范的數據e - r關系模型，並著重研究處于分散式系統中的列車運行圖數據信息的訪問權限和數據安全問題，提出以視圖模式結合用戶識別權限審定實現數據權限劃分，以並發處理、容錯技術、恢復技術提高系統的數據安全性；在基於b s架構的系統整體方案基礎上，對當前多種數據傳輸技術進行分析比較，採用b - isdn為主幹網、 adsl為接入端的基於公用數據網路分組交換技術的系統網路體系結構，並針對網路自身安全性和黑客攻擊與侵入問題，詳細討論綜合採用差錯控制、防火墻、數據加密解密等技術手段提高系統的網路安全性能。
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