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Data compression using a WORD-based model and revised arithmetic coding method.
標簽： compression arithmetic WORD-based revised
上傳時間： 2013-12-24
上傳用戶：zsjinju
We address the problem of predicting a word from previous words in a sample of text. In particular, we discuss n-gram models based on classes of words. We also discuss several statistical algorithms for assigning words to classes based on the frequency of their co-occurrence with other words. We find that we are able to extract classes that have the flavor of either syntactically based groupings or semantically based groupings, depending on the nature of the underlying statistics.
標簽： predicting particular previous address
上傳時間： 2016-12-26
上傳用戶：xfbs821
) Compression using huffman code -with a number of bits k per code word -provide huffman table Huffman coding is optimal for a symbol-by-symbol coding with a known input probability distribution.This technique uses a variable-length code table for encoding a source symbol. The table is derived in a particular way based on the estimated probability of occurrence for each possible value of the source symbol .Huffman coding uses a specific method for representing each symbol, resulting in a prefix code that expresses the most common characters using shorter strings of bits than those used for less common source symbols.The Huffman coding is a procedure to generate a binary code tree.
標簽： code Compression huffman provide
上傳時間： 2017-05-30
上傳用戶：yuchunhai1990
基于TMS320F2812 光伏并網發電模擬裝置PROTEL設計原理圖+PCB+軟件源碼+WORD論文文檔,硬件采用2層板設計，PROTEL99SE 設計的工程文件，包括完整的原理圖和PCB文件，可以做為你的學習設計參考。 摘要：本文實現了一個基于TMS320F2812 DSP芯片的光伏并網發電模擬裝置，采用直流穩壓源和滑動變阻器來模擬光伏電池。通過TMS320F2812 DSP芯片ADC模塊實時采樣模擬電網電壓的正弦參考信號、光伏電池輸出電壓、負載電壓電流反饋信號等。經過數據處理后，用PWM模塊產生實時的SPWM 波，控制MOSFET逆變全橋輸出正弦波。本文用PI控制算法實現了輸出信號對給定模擬電網電壓的正弦參考信號的頻率和相位跟蹤，用恒定電壓法實現了光伏電池最大功率點跟蹤（MPPT），從而達到模擬并網的效果。另外本裝置還實現了光伏電池輸出欠壓、負載過流保護功能以及光伏電池輸出欠壓、過流保護自恢復功能、聲光報警功能、孤島效應的檢測、保護與自恢復功能。系統測試結果表明本設計完全滿定設計要求。關鍵詞：光伏并網，MPPT，DSP Photovoltaic Grid-connected generation simulator Zhangyuxin，Tantiancheng，Xiewuyang(College of Electrical Engineering, Chongqing University)Abstract: This paper presents a photovoltaic grid-connected generation simulator which is based on TMS320F2812 DSP, with a DC voltage source and a variable resistor to simulate the characteristic of photovoltaic cells. We use the internal AD converter to real-time sampling the referenced grid voltage signal, outputting voltage of photovoltaic, feedback outputting voltage and current signal. The PWM module generates SVPWM according to the calculation of the real-time sampling data, to control the full MOSFET inverter bridge output sine wave. We realized that the output voltage of the simulator can track the frequency and phase of the referenced grid voltage with PI regulation, and the maximum photovoltaic power tracking with constant voltage regulation, thereby achieved the purpose of grid-connected simulation. Additionally, this device has the over-voltage and over-current protection, audible and visual alarm, islanding detecting and protection, and it can recover automatically. The testing shows that our design is feasible.Keywords: Photovoltaic Grid-connected，MPPT，DSP 目錄引言 11. 方案論證 11.1. 總體介紹 11.2. 光伏電池模擬裝置 11.3. DC-AC逆變橋 11.4. MOSFET驅動電路方案 21.5. 逆變電路的變頻控制方案 22. 理論分析與計算 22.1. SPWM產生 22.1.1. 規則采樣法 22.1.2. SPWM 脈沖的計算公式 32.1.3. SPWM 脈沖計算公式中的參數計算 32.1.4. TMS320F2812 DSP控制器的事件管理單元 42.1.5. 軟件設計方法 62.2. MPPT的控制方法與參數計算 72.3. 同頻、同相的控制方法和參數計算 8
標簽： tms320f2812 光伏 并網發電 模擬 protel pcb
上傳時間： 2021-11-02
上傳用戶：
LED路燈測試標準及試驗方法 Word
上傳時間： 2013-08-03
上傳用戶：eeworm
圖解Word 2000中文版
上傳時間： 2013-05-28
上傳用戶：eeworm
New-尚未歸類-412冊-8.64G Word.2003.Excel.2003商務辦公與應用-287M.zip
上傳時間： 2013-04-24
上傳用戶：410805624
譚浩強C語言word版，總共十三個部分，是一本很經典的c語言教程
上傳時間： 2013-06-24
上傳用戶：tyg88888
譚浩強C語言教程Word版.rar 譚浩強C語言教程Word版.rar
上傳時間： 2013-07-11
上傳用戶：stella2015
資料->【E】光盤論文->【E1】斯坦福博士論文->02 calgary PhD A Java-Based Wireless Framework for Location-Based Services Applications.pdf
標簽： Location-Based Applications Java-Based Framework
上傳時間： 2013-07-02
上傳用戶：亞亞娟娟123
