multilevel signal 中文意思是什麼

Through analysising the characteristics of the power system with floating neutral point deeply, the paper puts forward a new plan of single - phase to ground fault line selection on the base of s ' s signal injecton method and gives the hardware and software design. in this design, the high speed sampling and data processing is carried out through using dsp processor ; the large electrice current is drived through the application of a high - performance audio power amplifier and transformer ; the communication between host computer and detectors is realized through rs485 bus technology ; the difference multilevel frequency - selected amplifier is designed and the feeble signal of space is sampled on the base of the theory of magnetic induction ; the interface between dsp and exterior chip and rs485 interface logical is designed through using fpga ; the using of lcd module and keyboard interfacing chip makes the interface between human and machine ; the programme of host computer and detectors is designed through using blocking design method

在本設計中，採用高速的dsp處理器，實現了對故障特徵信息的高速採集與處理;採用大功率的功放晶元與變壓器配合的方法，實現了大電流信號的驅動輸出;採用485總線技術，組建了裝置主機與多探測器之間的主從式通訊網路，實現了多干擾條件下裝置主機與多探測器的可靠通訊;設計了差分式多級選頻放大電路，採用磁感應的方法實現了對空間微弱信號的接收;利用fpga技術，實現了控制器與多外設的介面及數字信號的串並轉換;採用了先進的lcd液晶顯示模塊及鍵盤介面晶元，設計了人機信息交互的介面;採用了模塊化的軟體設計方法，開發了裝置主機及探測器的軟體程序。

The first chapter in this paper provides a survey of data mining technology, and explains basic concepts, function and the whole framework of data mining and difficulties in developing and some future directions in association rule generation ; the second chapter introduce the basic concepts, brings forward a classification of association rule ; the third chapter give a deep research on algorithms of every kind of association rule, include mining single - dimensional signal - level association rule and multidimensional multilevel association rule, it describes these algorithm, point out some method to optimize this algorithm and test its quality with experiments ; the fourth and fifth chapter introduce the designs about association rule mining system basing on relation database visual foxpro in detail : according to system frame of the association rule mining, actualize a new mining algorithms and analyses every function module of program, at last further analyses the left problems in designs

本論文第一部分對數據挖掘技術進行了總體介紹，說明了基本概念、功能和系統總體框圖以及發展中的難點和研究方面；第二章對關聯規則基本概念的進行了介紹，提出了關聯規則的分類方法；第三章探討了挖掘各種關聯規則的演算法，從挖掘單維單層布爾關規則的經典的apriori開始，分析了挖掘單維、多層關聯規則的演算法，多維關聯規則的演算法到多維多值屬性關聯規則的演算法。文中提出演算法優化方法，並對其性能進行了實驗測試；第四部分、第五部分詳細介紹了基於關系型數據庫的關聯規則挖掘系統的設計構思，根據關聯規則挖掘系統結構框架，實現了基於visualfoxpro的關聯規則挖掘系統，其于採用了一個新型的基於關系數據庫的關聯規則挖掘演算法，提高了挖掘效率，並詳細分析了程序設計的各個功能模塊，最後就設計中遺留的問題進行了進一步的分析。

We use polyinstance to eliminate the covert signal channel in the multilevel secure database, so we must change the traditional relational data modal

本文引入了多實例以解決多級數據庫中的隱蔽信號通道，因此必須對傳統的關系模型進行根本變革。