第一篇：英文翻譯

應(yīng)用四種算法對機(jī)器人PID控制器設(shè)計(jì)的比較研究 網(wǎng)上發(fā)表時間：2010年6月

Mohammad-Taghi Vakil-Baghmisheh · Mina Salim ? Springer Science+Business Media B.V.2010

本文比較了四種PID控制器混合進(jìn)化算法控制機(jī)器人的表現(xiàn)，我們盡量減少瞬時狀態(tài)階躍響應(yīng)。為此，一個函數(shù)階躍響應(yīng)的一些參數(shù)（超調(diào)量，調(diào)節(jié)時間時間，上升時間和穩(wěn)態(tài)誤差）的定義。我們?yōu)榱吮M量減少瞬時狀態(tài)階躍響應(yīng)，對四種算法的結(jié)果進(jìn)行了比較，四種算法即粒子群優(yōu)化算法（PSO），蜂群優(yōu)化算法（QB），遺傳算法（GA），SCE算法（shuffled complex evolution）。

在PID控制器設(shè)計(jì)中，我們要在測試的幾種方法的基礎(chǔ)上獲得的結(jié)果，以便我們可以選擇一個最好的方法，在我們以往的經(jīng)驗(yàn)中，關(guān)節(jié)1, 2,和4用QB算法, 關(guān)節(jié)3用基因遺傳算法,關(guān)節(jié)5用復(fù)雜演化算法取得了很好地效果

關(guān)鍵詞：Gryphon robot · Queen-bee · Particle swarm · Shuffled complex evolution ·Nelder–Mead 1 介紹

由于其簡單性和高效率，PID控制器被廣泛應(yīng)用于各個行業(yè)。PID控制器的傳遞函數(shù)為公式1。

其中Kp為比例增益，KD為微分增益，Ki是積分增益，他們都是變量。通常確定這些參數(shù)值的準(zhǔn)確值和誤差的方法是時域分析和計(jì)算。

近年來，PID控制器設(shè)計(jì)的一些新的方法已被使用，其中包括遺傳算法GA（荷蘭1975），蟻群算法(Hsiao and Chuang 2004),粒子群優(yōu)化算法(Gaing 2004),模擬退火算法(SA)(Zhou and Birdwell 1994), 蜂群算法(Luˇci′c and Teodorovi′c 2001;Luˇci′c and Teodorovi′c 2003),，這只是其中一部分算法。

利用這些算法，我們可以把PID控制器的設(shè)計(jì)問題轉(zhuǎn)化為一個函數(shù)問題，從而得到優(yōu)化。在本文中，我將通過機(jī)器人的不同表現(xiàn)，比較四種不同的算法。為此我們定義了一個以階躍響應(yīng)的四個參數(shù)為變量的函數(shù)，四個參數(shù)為超調(diào)量，調(diào)節(jié)時間Ts，上升時間Tr，穩(wěn)態(tài)誤差Ess，并使用進(jìn)化算使成本函數(shù)最小化。本文的余下部分安排如下，第二部分介紹機(jī)器人及其參數(shù)，第三部分比較分析GA,PSO,QB和NM方法。第四部分，SEC的算法描述。在第五部分，我們分別用GA,PS,NM,QB-NM,SCE算法的PID控制器設(shè)計(jì)機(jī)器人。第六部分，我們對設(shè)計(jì)的結(jié)果進(jìn)行介紹和討論。第七部分為總結(jié)。2 機(jī)器人介紹

機(jī)器人有五個自由度控制他的關(guān)節(jié)轉(zhuǎn)動，（見表1）我們把他的肩，肘，腕三個關(guān)節(jié)的表現(xiàn)記錄下來，除了精度，連續(xù)性和速度是他的兩個重要表現(xiàn)。這個機(jī)器人由四個微處理器控制，一個控制機(jī)器人的各個節(jié)點(diǎn)，兩個微處理器控制電機(jī)，第四個與前三個同步，并使四個微處理器與電腦主機(jī)建立正確關(guān)系。

控制每個軸的步進(jìn)電機(jī)需要與一個編碼器聯(lián)合、反饋。由于在機(jī)器人設(shè)計(jì)中應(yīng)用的齒輪比較高，所以機(jī)器人的動作緩慢。機(jī)器人的關(guān)節(jié)都可以獨(dú)立控制。表1 給

出了各個關(guān)節(jié)的傳遞函數(shù)，這些函數(shù)是在Tabriz大學(xué)的機(jī)器人研究實(shí)驗(yàn)室研究出來的。

3.進(jìn)化算法的綜述

在合理的時間里，進(jìn)化算法可以獲取困難問題的最理想解決方案，而那些經(jīng)典方法無法獲得。這些算法被稱為最理想是因?yàn)橥ǔＦ渌惴]有辦法證明他們是最優(yōu)秀的。在本文中，我們將討論這四種算法，他們分別是遺傳法，粒子群法，蜂群優(yōu)化算法，SCE算法。3.1 遺傳算法

遺傳算法是在1975年由荷蘭引入，他對自然遺傳算法的優(yōu)化有所啟發(fā)，遺傳算法不需要衍生信息，甚至成本函數(shù)在搜索空間不需要連續(xù)。模型的變量在特定的環(huán)境中變化。我們把這些變量稱為染色體，以便提高方案和算法的質(zhì)量，為此，操作人員在預(yù)定的迭代函數(shù)中對變量染色體操作，這些操作人員對染色體進(jìn)行選擇，交叉和變異。在下面，我們簡要的介紹那些操作人員在連續(xù)變量上對染色體的操作。

選擇：選擇算子應(yīng)用于染色體。

染色體往往是隨機(jī)選取的，在本文中，我們利用rollet——wheel選擇方法。交叉算子工程的兩個后代是由選定的成員決定。為此，一個基因的位置是隨機(jī)選擇的，相應(yīng)的基因（xm和xd）是由兩個新值取代。

其中隨機(jī)數(shù)β的范圍是0到1，位于選定的基因后的其他基因與雙方父母的染色體交換。一次一個基因突變，變量的基因隨機(jī)選取了突變率。然后，這些基因被搜索空間中的隨機(jī)變量替換。3.2 PSO算法

PSO算法最初在1995年由Kennedy和Eberhar提出。是起源對簡單社會系統(tǒng)的模擬。動物的小組成員們和他們的同伴共享他尋找食物過程中最佳位置的信息。因此，PSO算法是（Kennedy和Eberhar2004）在搜索個人和社會經(jīng)驗(yàn)的結(jié)合。PSO算法中的每個成員稱為粒子，每個粒子在搜索空間中有位置矢量和速度矢量。每個粒子根據(jù)自身和變量更新他的位置和速度矢量。根據(jù)下列公式（Kennedy等人，2001年）第i個粒子改變他的速度和位置。

其中W表示慣性權(quán)重因子，Pi是第i個粒子的最佳位置，目前為止，PG是所有變量的所有粒子的最佳位置。C1，C2是通常被稱為學(xué)習(xí)因素，是常數(shù)，D表示問題空間的維數(shù)，rand1和rand2是兩個隨機(jī)量，范圍0到1.3.3 QB算法

QB算法（2003年Nkrani）是一個相對比較新的集體搜索算法，QB算法已被用于廣闊范圍的優(yōu)化問題，如多變量問題（2007，karaboga等），非線性約束問題（tai等，2004）聚類（fathian，2007），基于LVQ（fan，2006）和前饋神經(jīng)網(wǎng)絡(luò)（karaboga，2007）等。如各種神經(jīng)網(wǎng)絡(luò)的訓(xùn)練。他的基因，種群，選擇，交叉，變異，繁殖與遺傳算法的一些常見概念。然而，它與標(biāo)準(zhǔn)的遺傳算法有兩個區(qū)別：1.變量的最好成員由一體的父母（蜂王）固定2.它使用了兩個不同的突變率，即正常的突變率和更大的突變率。在排序的基礎(chǔ)上增加成本函數(shù)值和一些染色體變異與正常突變率，防止算法過早收斂，其中兩個不同突變率與突變變量之間的比例為ζ。3.4 Nelder–Mead算法

NM單純算法是一種非梯度優(yōu)化法，通常用于本地搜索。他采用了啟發(fā)式的搜索策略，只需要評估成本函數(shù)（baharlouei，2006）。一個單純的多面體，頂點(diǎn)比變量數(shù)目更多，如2維空間中的三角形。它的N+1個頂點(diǎn)，每個都是一個潛在的問題解決方案。每一步中最壞的點(diǎn)表現(xiàn)為這個點(diǎn)沿其他N個點(diǎn)的質(zhì)心方向

一個網(wǎng)關(guān)的算法詳細(xì)解釋如下：

3.4.1 NM單純形算法

設(shè)定初始化的基本搜索點(diǎn)，選擇n個其他點(diǎn)，選擇公式如下

其中λi是一個隨機(jī)數(shù)，范圍0到1，ei是第i維的單位向量。

1.令n+1個頂點(diǎn)單純滿足F（X1）≤F（X2）≤???≤F（Xn+1）2.反射：計(jì)算反射點(diǎn)和它的值

3.根據(jù)Fr的相對值，下列四種情況的相對值可能出現(xiàn)。a.若Fr

若Fe

c．F（xn）

d．Fr≥F（Xn+1），執(zhí)行里面的收縮，即計(jì)算Xcc和評估F（Xcc）：

如果Fcc

和在這些新的點(diǎn)（新的單純圖形的頂點(diǎn)）評估F（x）5.如果停止條件得不到滿足，重復(fù)第一步算法。

4.Shuffled復(fù)雜演化法

SCE方法是一種啟發(fā)式的優(yōu)化方法，是由duan等人在1992年提出，他的表現(xiàn)如下：

4.1 SCE算法

1.在搜索空間形成Npop的隨機(jī)點(diǎn) 2.為每個值評估原函數(shù)

3.對函數(shù)值按原函數(shù)增加的順序進(jìn)行排序 4.對復(fù)雜值P進(jìn)行劃分 5.進(jìn)化

A．q隨機(jī)的指向每一個復(fù)雜選擇并劃分這些復(fù)雜點(diǎn)

B．消除每個復(fù)雜點(diǎn)的最壞點(diǎn)，并計(jì)算其他平均值，反映到Xw

C．如果（Fr

如果Fc

5.PID控制器設(shè)計(jì)：

其中kp，ki，kd為比例，微分，積分增益.階躍響應(yīng)的超調(diào)量MP，總時間ts，上升時間tr和穩(wěn)態(tài)誤差ess可作為PID控制器的性能參數(shù)。這樣的設(shè)計(jì)，將是一個多目標(biāo)優(yōu)化的問題。我們定義一個單一的原函數(shù)，使一個單一目標(biāo)問題轉(zhuǎn)換到多目標(biāo)問題。

其中，β是加權(quán)因子。β<0.7，tr和ts受影響較大，對β> 0.7，MP和ESS受影響較大，如果β= 0.7，對所有四項(xiàng)的影響是一樣的。為了評估每個染色體，我們將基因帶入控制器的傳遞函數(shù)，這也可以計(jì)算系統(tǒng)的階躍響應(yīng)。通過對原函數(shù)的評價來獲取ESS,MP ,Tr和Ts，我們?yōu)镵,p Kd ,Ki 設(shè)定一個上限和下限值，分別為150，-50.β值等于0.7

6.仿真結(jié)果

在本文中，我們將提到的進(jìn)化算法結(jié)合起來使用以實(shí)現(xiàn)更好的結(jié)果，除了SCE。（SCE的方法包括內(nèi)爾德米德法的修訂版本）。每次網(wǎng)關(guān)算法完成后，運(yùn)行20次迭代。每種算法的參數(shù)值在下面給出。

GA-NM算法參數(shù)設(shè)置

選擇速率為0.6，突變率為0.01，值為10。表2給出GA-NM算法的迭代次數(shù)。PSO-NM算法的參數(shù)設(shè)置（所有關(guān)節(jié)）。

QB-NM算法的參數(shù)設(shè)置

選擇率為0.6，正常突變率為0.2.強(qiáng)突變率為0.4，ζ= 0.7，迭代數(shù)= 70 SEC算法的參數(shù)設(shè)置如表3

所有關(guān)節(jié)的階躍響應(yīng)如圖3,4,5,6和7.。PID參數(shù)和各關(guān)節(jié)的階躍響應(yīng)在表4,5,6,7,8中。從結(jié)果中我們可以看到，前三個關(guān)節(jié)的QB-NM算法，由SCE算法計(jì)算的接點(diǎn)4和5需要最小的計(jì)算時間。但由于設(shè)計(jì)PID控制器是脫機(jī)的過程中計(jì)算時間并不是最重要的因素。在機(jī)器人控制器的設(shè)計(jì)中，除了成本函數(shù)，減少超調(diào)超調(diào)量是最重要。

為聯(lián)合1和2，新墨西哥州的QB-NM算法建立的函數(shù)值足夠小，并且超調(diào)量是0.因此，QB-NM算法是關(guān)節(jié)1和2PID控制器設(shè)計(jì)的首選算法。為聯(lián)合3，SCE算法實(shí)現(xiàn)最小成本函數(shù)值，但他可以拉開機(jī)器人的軟議案。然后，我們更傾向于使用這一配合設(shè)置，因?yàn)镚A-NM算法設(shè)計(jì)的PID控制器的成本價值小，超調(diào)量小。用類似的方式，可以得出結(jié)論，QB-NM算法設(shè)計(jì)的控制器最好聯(lián)合4.。為聯(lián)合5，使用SCE算法是最好的，因?yàn)榭梢詫?shí)現(xiàn)0超調(diào)量，并且cost value足夠小。

7.結(jié)論 在本文中，我們設(shè)計(jì)的機(jī)器人PID控制器使用四個進(jìn)化算法控制機(jī)器人關(guān)節(jié)，即GA-NM,PSO-NM,QB-NM,SCE算法。為此，我們采用了階躍響應(yīng)的四個特殊變量，ESS,MP，Tr,Ts，并且定義的代價函數(shù)包含這些功能和最小代價函數(shù)。這樣，我們將一個單目標(biāo)函數(shù)的優(yōu)化問題轉(zhuǎn)換為多目標(biāo)函數(shù)的優(yōu)化問題。在一般情況下，一個算法的優(yōu)劣不能被直接看出。在機(jī)器人PID控制器設(shè)計(jì)的方法中，我們可以根據(jù)結(jié)果選擇最好的一個。這種情況下，結(jié)果表明，接頭1。2和4用QB-NM算法，接頭3用GA-NM算法，5用SCE算法是最合適的

1.PID 控制器比例積分微分控制器（PID 調(diào)節(jié)器）是一個控制環(huán)，廣泛地應(yīng)用于工業(yè)控制系統(tǒng)里的 反饋機(jī)制。PID 控制器通過調(diào)節(jié)給定值與測量值之間的偏差，給出正確的調(diào)整，從而有規(guī) 律地糾正控制過程。PID 控制器算法涉及到三個部分：比例，積分，微分。比例控制是對當(dāng)前偏差的反應(yīng)，積分控制是基于新近錯誤總數(shù)的反應(yīng)，而微分控制則是基于錯誤變化率的反應(yīng)。這三種控 制的結(jié)合可用來調(diào)節(jié)過程系統(tǒng)，例如調(diào)節(jié)閥的位置，或者加熱系統(tǒng)的電源調(diào)節(jié)。根據(jù)具體 的工藝要求，通過 PID 控制器的參數(shù)整定，從而提供調(diào)節(jié)作用。控制器的響應(yīng)可以被認(rèn)為 是對系統(tǒng)偏差的響應(yīng)。注意一點(diǎn)的是，PID 算法不一定就是系統(tǒng)或系統(tǒng)穩(wěn)定性的最佳控制。一些應(yīng)用可能只需要運(yùn)用一到兩種方法來提供適當(dāng)?shù)南到y(tǒng)控制。這是通過把不想要的 控制輸出置零取得。在控制系統(tǒng)中存在 P,PI,PD,PID 調(diào)節(jié)器。PI 調(diào)節(jié)器很普遍，因?yàn)槲⒎?控制對測量噪音非常敏感。積分作用的缺乏可以防止系統(tǒng)根據(jù)控制目標(biāo)而達(dá)到它的目標(biāo) 值。注釋：由于控制理論和應(yīng)用領(lǐng)域的差異，很多相關(guān)變量的命名約定是常用的。控制環(huán)基礎(chǔ) 一個關(guān)于控制環(huán)類似的例子就是保持水在理想溫度，涉及到兩個過程，冷、熱水的混 合。人可以憑觸覺估測水的溫度。基于此他們設(shè)計(jì)一個控制行為：用冷水龍頭調(diào)整過程。重復(fù)這個過程，調(diào)節(jié)熱水流直到溫度處于期望的穩(wěn)定值。感覺水溫就是對過程值或變量的測量。期望得到的溫度稱為給定值。控制器的輸出對 象和過程的輸入對象稱為控制參數(shù)。測量值與給定值之間的差就是偏差值，太高、太低或 正常。作為一個控制器，在確定溫度給定值后，就可以粗略決定改變閥門位置多少，以及 怎樣改變偏差值。首次估計(jì)即是 PID 控制器的比例度的確定。當(dāng)它幾乎正確時，PID 控 制器的積分作用就是起著逐漸調(diào)整溫度的作用。微分作用就是根據(jù)水溫變得更熱、更冷，以及變化速率來決定什么時候、怎樣調(diào)整那些閥門。當(dāng)偏差小時而做了一個大變動，相當(dāng) 于一個大的調(diào)整控制器，會導(dǎo)致超調(diào)。如果控制器反復(fù)進(jìn)行大的變動并且反復(fù)越過給定值 的改變，控制環(huán)將會不穩(wěn)定。輸出值將在期望值或一常量周圍擺動，甚至破壞系統(tǒng)穩(wěn)定性。人不會這樣做，因?yàn)槲覀兪怯兄腔鄣目刂迫藛T，可以從歷史經(jīng)驗(yàn)中學(xué)習(xí)，但 PID 控制器沒 有學(xué)習(xí)能力，必須正確的設(shè)定。為有效的控制系統(tǒng)選擇正確的參數(shù)被稱為整定控制器。如果控制器在零偏差從穩(wěn)定開始，然后進(jìn)一步的變化將導(dǎo)致其它一些影響過程的能測 量、不能測量值的變化，并且作用于偏差值上。除主過程以外，其他的對擾動有影響的過 程可以用來抑制擾動或?qū)崿F(xiàn)對目標(biāo)值的改變。供給水溫的變化就構(gòu)成了對過程的一個擾 動。理論上，控制器能用來控制可測量對象，以及可以影響偏差的輸出、輸入標(biāo)準(zhǔn)值的所 有過程參數(shù)。控制器在工業(yè)中被用來調(diào)節(jié)溫度，壓力，流速，化學(xué)組成，速度以及其它任 何存在可測量的對象。汽車游覽控制就是一個自動化的過程控制的例子。由于它們悠久的歷史，簡易，良好的理論基礎(chǔ)以及簡單的設(shè)置、維護(hù)要求，PID 控制 器被許多應(yīng)用實(shí)踐所采納。

2.PID 控制器理論 注釋： 這部分描述PID 控制器理想平行或非相互作用的形式。關(guān)于其他形式，“其 請看 它的表達(dá)式和 PID 形式”這部分。PID 控制是根據(jù)它的三個參數(shù)而命名的，三參數(shù)結(jié)合起來就形成控制參數(shù)。因此： Pout，Iout 和 Dout 是控制器的三個參數(shù)，下面分別予以確定。

2.1 比例度 比例度是根據(jù)當(dāng)前的錯誤值而做出的變動。比例度可以通過恒定的 Kp 增加來調(diào)整，稱為比例增益。比例度計(jì)算如下： Pout:比例度 Kp：比例系數(shù)，協(xié)調(diào)參數(shù)。e:偏差=SP-PV t:時間或瞬時時間（當(dāng)前的）一個高的比例增益產(chǎn)生于一種輸出值的大的變化。如果比例增益太高，系統(tǒng)將變得不 穩(wěn)定。響應(yīng)地，一個小的調(diào)整產(chǎn)生于一小的輸出變化，而如果比例增益太低，當(dāng)對系統(tǒng)振 蕩作出反映時，控制作用可能太小。缺少擾動的情況下，純粹的比例控制不能完全解決問題，但是將保留從過程中獲得的 具有比例增益的功能的穩(wěn)態(tài)偏差。盡管有穩(wěn)態(tài)補(bǔ)償，理論和工業(yè)實(shí)踐都表明比例度在輸出 2 控制中起到大部分的作用。

2.2 積分值 積分值的大小與偏差的大小及持續(xù)時間成正比。根據(jù)即時的超時的錯誤改正，進(jìn)行積 累補(bǔ)償。積累的誤差通過積分調(diào)節(jié)后再作用于輸出。對總的控制作用的積分大小由積分時 間常數(shù)來決定，即 Ki，積分值計(jì)算如下： Iout：積分值 Ki:積分時間常數(shù)，協(xié)調(diào)參數(shù) e:偏差=SP-PV ζ：積分時間 積分值加速面向設(shè)定值的過程運(yùn)動并且消除殘余的只與控制器發(fā)生作用的穩(wěn)態(tài)偏差。然而，因?yàn)榉e分從過去的積累誤差作出反應(yīng)，引起當(dāng)前的值越過設(shè)定值（跨過設(shè)定值向其 它方向改變）。想了解更多的關(guān)于積分和控制器穩(wěn)定度的知識，請參見關(guān)于環(huán)路調(diào)諧的部分

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Baharlouei A, Abdolhassani B, Oraizi H(2006)A new smart antenna for CDMA using Nelder–Mead simplex algorithm and ESPAR antenna.In: Proceeding of IEEE Conference on Inf Commun Technol, Vol.2, pp 2748–2753 Duan Q, Sorooshian S, Gupta VD(1992)Effective and efficient global optimization for conceptual rainfall runoff models.Water Resour Res 28(4):1015–1031 Emara MH, Abdel Fattah HA(2004)Continuous Swarm Optimization Technique with Stab Anals Faculty ofEngineering.Cairo University, American Control Conference Boston, pp 2811–2817 Fathian M, Amiri B,MaroosiA(2007)Application of honey-beemating optimization algorithm on clustering.Appl Math Comput 190(2):1502–1513 Fernandes C, Rosa A(2001)A study on non-random mating and varying population size in genetic algorithms using a royal road function.In: Proceedings of the 2001 congress on evolutionary computation.IEEE Press, Piscataway, NJ, pp 60–66 Gaing L(2004)A particle swarm optimization approach for optimum design of PID controller in AVR system.In: IEEE international conference on energy conversion, pp 384–391 Holland J(1975)Adoption in natural and artificial systems.University of Michigan Press, Michigan Hsiao YT, Chuang CL(2004)Ant colony optimization for designing of PID controllers.In: IEEE international symposium on comp.aided control systems design, Taiwan Karaboga D, Basturk B(2007)A powerful and efficient algorithm for numerical function optimization: artificial bee colony.Glob Optim 39:459–471 Karaboga V, Akay B, Ozturk C(2007)Artificial bee colony(ABC)optimization algorithm for training feedforward neural networks.Model Decis Artif Intell 461:318–329 Kennedy J, Eberhart R(1995)Part swarm optimization.In: Proceedings IEEE international conference on neural networks, pp 1942–1948 Kennedy J, Eberhart RC, Shi Y(2001)Swarm Intell.Morgan Kaufmann, NewYork KoudilM, Benatchba K, Tarabet A, Batoul Shahraoui EI(2007)Using artificial bees to solve partitioning and scheduling problems in codesign.Appl Math Comput 186(2):1710–1722 Luˇci′c P, Teodorovi′c D(2001)Bee system: modeling combinatorial optimization transportation engineering problems by swarm intelligence.In: Preprints of the TRISTAN IV triennial symposium on transportation analysis.Portugal, pp 441–45 Luˇci′c P, Teodorovi′c D(2003)Computing with bees: attacking complex transportation engineering problems.Int J Artif Intell Tools 12(3):375–94 Nakrani S, Tovey C(2003)On honey bees and dynamic allocation in an internet server colony.In: Proceedings of 2nd international workshop on the mathematics and algorithms of social insects, USA Pham DT, Orti S, Ghanbarzadeh A, Koc E(2006)Application of bees algorithm to the training of learning vector quantization networks for control chart pattern recognition.In: Intelligent robots and systems ‘3，IROS ‘3.Proceedings of the 1993 IEEE/RSJ international conference on, vol 1, pp 629–35 Qin LD, Jiang QY, Zou ZY, Cao YJ(2004)A queen-bee evolution based on genetic algorithm for economic power dispatch.In: 39th international universities power engineering conference(UPEC 2004)Bristol, UK, pp 453–56

第二篇：英文翻譯

Introduction: with the rapid development of the economy, China ‘smprehensive national power has been improved effectively.As a saying said;“Want to become rich first road”.So China has begun to build the high-speed rail since years ago.The building of the high~speed rail is suited to China's national conditions and help our country to run well in the strong competition of the world.大多數(shù)經(jīng)濟(jì)學(xué)家認(rèn)為：交通基礎(chǔ)設(shè)施的供應(yīng)水平和能力必須適度超前，否則就會影響社會經(jīng)濟(jì)持續(xù)、穩(wěn)定 和健康發(fā)展。這就意味著要加大對交通基礎(chǔ)設(shè)施的投資，但是政府在加大交通基礎(chǔ)設(shè)施投資力度的同時，用于改善民生的措施實(shí)際卻在相對地減少。從中國目前的經(jīng)濟(jì)發(fā)展和人民的收入狀況來說，我認(rèn)為中國高 鐵弊大于利.Most economists believe that: the supply and capability of transportation infrastructure must advance appropriately, otherwise it will affect the sustainable, stable and healthy development of social economy.This means that we have to increase the investment into transportation infrastructure,But while government increase the investment into transportation infrastructure, it will to some extent decrease the practical measures to improve people's livelihood.From China's current situation, I think it will do more harm than good to build high-speed railway in China.Piont1: Building too fast go against the laws of economic development, causing many problems, such as loan repayment, staff placement.And high-speed railway construction needs large investment, from the use of the actual situation, the possibility of short-term cost recovery do not, there is also the problem of capital wasting.建設(shè)速度過快，容易違背經(jīng)濟(jì)發(fā)展規(guī)律,同時面對的問題較多，例如貸款償還，員工安置等。中國第一條高 鐵客運(yùn)專線——從北京到天津，它在 2008 年 8 月通車后一年就虧損了 7 個億。武廣高鐵總投資約 1166 億元，目前的線路至少能開 120 對車，但實(shí)際上只開了 33 對，而且還坐不滿，這是資本的嚴(yán)重浪費(fèi)。所 以說高鐵建設(shè)不僅需要大筆的投資，而且從運(yùn)用的實(shí)際的情況來看，短期收回成本的可能性根本就沒有。The fast building speed will violate the rule of economic development, and at same time it faced many problems, such as loan repayment, staff placement.First high-speed railway of China-from Beijing to Tianjin, it was launched in August 2008, after one year it lossed 70 millions.The total investment of

Wuhan-Guangzhou high-speed rail was about 110 billions yuan, now it is able to drive at least 120 pairs of cars, but in fact only 33 to drive, and lots of seats are empty, this is a serious waste of capital.The high-speed railway not only requires large construction investment, but also, it is impossible to recovery the short-term cost based on its actural implement.Poiimnt2: The building of the high spee

d rail can drive the development of the industry related.for example, the building need many workers and the new technology, so it expand the employment and promiot the technological innovation.In another word through the building, more steel products are needed.Another important hand is transport during the Spring Festival.During this period of time, large numbers of people going home together.So the high speed rail can relieve the transportation pressure ectively 高鐵的票價較高，例如京津高鐵，它行駛 30 分鐘，卻要 69 元票價，讓人望而生嘆啊。中國的 GDP 總量 高居世界第二，但人均 GDP 在世界的排名卻還在百名開外，窮人還是絕大多數(shù)。武廣高鐵開通后，原有 的一些客運(yùn)列車停運(yùn)，意味著中低收入者將被迫選擇高鐵，接受高票價。這種行為傷及了底層人民的最根 本利 e 而且建設(shè)過程中容易出現(xiàn)貪污腐敗問題。The fare of high Speed Rail is higher, for example, the Beijing-Tianjin high-speed rail, it costs 69 yuan for only drive 30minuts.China's GDP ranks the second in the world, but per capita GDP still ranks out of hundreds in the world, the poor is the majority.When Wuhan-Guangzhou high-speed railway was used, the original passenger trains were stopped, which means low-incomer will be forced to choose high-speed rail and accept the high fares.This action has

impair interests of the low class people, and the corruption problem will be prone to easily during the process of building.新建高鐵實(shí)際是在現(xiàn)有幾種交通方式的基礎(chǔ)上新增一種交通方式。建成之后會與高速公路、現(xiàn)有鐵路、飛 機(jī)、船運(yùn)形成競爭關(guān)系，在原有運(yùn)力并不緊張的背景下必然形成運(yùn)力過剩。新建的高鐵主要是客運(yùn)專線，因此高鐵并不會加快貨物與資金的周轉(zhuǎn)速度，不會降低全社會運(yùn)行成本。要修建如此龐大的高速鐵路網(wǎng)，必將消耗大量的資金，必將擠占人們收入上漲的空間與企業(yè)利潤空間（加重稅負(fù)）如果將此財政投入醫(yī)療、。社保、教育、技術(shù)研究，則會消除人們存錢的預(yù)防養(yǎng)老動機(jī)從而擴(kuò)大消費(fèi)，利于中國經(jīng)濟(jì)可持續(xù)發(fā)展。綜 上所述，在中國大規(guī)模修建高鐵對中國經(jīng)濟(jì)的長遠(yuǎn)發(fā)展來講是弊大于利，不利于擴(kuò)大內(nèi)需、不利于產(chǎn)業(yè)結(jié) 構(gòu)調(diào)整 結(jié)論：The high-speed railway will compete with the existing highway, railway, aircraft, shipping after it consummation which will lead to a situation capacity.The new high-speed railway is mainly to carry passenger, so it will not speed up the turnover rate between cargos and the capital and will not decrease the costs of the whole social transportation.To build such a large network of high-speed rail will need a large amount of money, the government must increase the taxes of people and enterprise to raise the capital.If this financial investment used in health care, social security, education, tec

第三篇：英文翻譯

Overview of the Global System for Mobile Communications 1 History of GSM During the early 1980s, analog cellular telephone systems were experiencing rapid growth in Europe, particularly in Scandinavia and the United Kingdom, but also in France and Germany.Each country developed its own system, which was incompatible with everyone else’s in equipment and operation.This was an

undesirable situation, because not only was the mobile equipment limited to operation within national boundaries, which in a unified Europe were increasingly unimportant, but there was also a very limited market for each type of equipment, so economies of scale and the subsequent savings could not be realized.The Europeans realized this early on, and in 1982 the Conference of European s Posts and Telegraphs(CEPT)formed a study group called the Group Special Mobile(GSM)to study and develop a pan-European public land mobile system.The proposed system has to meet certain criteria: ·Good subjective speech quality ·Low terminal and service cost ·Support for international roaming ·Ability to support handheld terminals ·Support for range of new services and facilities ·Spectral efficiency ·ISDN compatibility In 1989, GSM responsibility was transferred to the European Telecommunication Standards Institute(ETSI), and phase I of the GSM specifications were published in 1990.Commercial service was started in mid-1991, and by 1993 there were 36 GSM networks in 22 countries.Although standardized in Europe, GSM is not only a European standard.Over 200 GSM networks are operational in 110 countries around the world.In the beginning of 1994, there were 1.3 million subscribers worldwide, which had grown to more than 55 million by October 1997.With North America making a delayed entry into the GSM field with a derivative of GSM called PCS1900, GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications.The developers of GSM chose an unproven(at the time)digital system, as opposed to the then-standard analog cellular systems like AMPS in the United States and TACS in the United Kingdom.They had faith that advancements in compression algorithms and digital signal processors would allow the fulfillment of the original criteria and the continual improvement of the system in terms of quality and cost.The over 8,000 pages of GSM recommendations try to allow flexibility and competitive innovation among suppliers, but provide enough standardization to guarantee proper interworking between the components of the system.This done by providing functional and interface descriptions for each of the functional entities defined in the system.2 General Concepts 2.1 Analog Versus Digital Telephony Systems First-generation systems were analog.During the early 1980s these underwent rapid development in Europe.Although the NMT system was used by all the Nordic countries, and the TACS system in the United Kingdom and Italy, there was a variety of systems and no compatibility among them.Compared with these systems, the main advantages offered by GSM, which is the most important of the second-generation digital systems, are: ·Standardization;·Capacity;·Quality;·Security.Standardization guarantees compatibility among systems of different countries, allowing subscribers to use their own terminals in those countries that have adopted the digital standard.The lack of standardization in the first-generation system limited service to within the borders of a country.Mobility is improved, since roaming is no longer limited to areas covered by a certain system.Calls can be charged and handled using the same personal number even when the subscriber moves from one country to another.Standardization also allows the operator to buy entities of the network from different vendors, since the functional elements of the network and the interfaces between these elements are standardized.This means that a mobile phone from any manufacturer is able to communicate with any network, even if this network is built with entities from different vendors.This leads to a large economy of scale and results in cost reduction for both the operator and the subscriber.Furthermore, the phone cost is also reduced, because GSM is an international standard, produced quantities are greater and the level of competition is high.With respect to capacity, the use of the radio resource is much more efficient in a digital system such as GSM than in an analog system.This means that more users can be allocated in the same frequency bandwidth.This is possible with the use of advanced digital techniques, such as voice compression algorithms, channel coding, and multiple access techniques.Note that capacity gains are also achieved with radio frequency reuse, which had also used in analog systems.Frequency reuse means that a given carrier can be employed in different areas.The quality in digital transmission systems is better, thanks to the channel coding schemes that increase the robustness in the face of noise and disturbances such as interference caused by other users or other systems.The quality improvement is also due to the improved control of the radio link, and adaptations to propagation conditions, with advanced techniques such as power control or frequency hopping.This will be explained in greater detail in the next section.In terms of security, powerful authentication and encryption techniques for voice and data communications are enabled with GSM, which guarantees protected access to the network, and confidentiality.2.2 Cellular Telephony In mobile radio systems, one of the most important factors is the frequency spectrum.In order to make the best use of the bandwidth, the system is designed by means of the division of the service area into neighboring zones, or cells, which in theory have a hexagonal shape.Each cell has a Base Transceiver Station(BTS), which to avoid interference operates on a set of radio channels different from those of the adjacent cells.This division allows for the use of the same frequencies in nonadjacent cells.A group of cells that as a whole use the entire radio spectrum available to the operator is referred to as a cluster.The shape of a cell is irregular, depending on the availability of a spot for the BTS, the geography of the terrain, the propagation of the radio signal in the presence of obstacles, and so on.In dense urban areas, for instance, where the mobile telephony traffic is important, the diameter of the cells is often reduced in order to increase capacity.This is allowed since the same frequency channels are used in a smaller area.On the other hand, reducing the cell diameter leads to a decrease in the distance necessary to reuse the frequencies(that is, the distance between two co-channel cells), increasing co-channel interference.In order to minimize the level of interference, several techniques are used on the radio interface.A basic example of cluster organization is shown in Figure 1.In this example, we see a reuse attern for seven different frequencies, f1 to f7.These frequencies correspond to the beacon carrier of each cell, on which signaling information about the cell is broadcast(see Section 2.7).It can be seen from this figure that a given carrier can be reused in two separate geographical areas, as long as these areas are far enough from each other to reduce the effect of interference.With this technique of dividing the area in cells and clusters, the operator can increase the area it is able to cover with a limited frequency bandwidth.Figure 1 Example of a Cell Planning

在80 年代初期期間，模式手機(jī)系統(tǒng)在歐洲體驗(yàn)迅速增長，特別在斯堪的那

維亞和英國，以及法國和德國。每個國家開發(fā)了它自己的系統(tǒng)，在設(shè)備和操作 上是互不相容的。這是一個不受歡迎的情況，因?yàn)椴粌H移動通信設(shè)備被限制在國 界之內(nèi)，這在統(tǒng)一的歐洲是越來越不重要的，而且每種類型的設(shè)備都只有一個非 常有限的市場，因此經(jīng)濟(jì)尺度及隨后的儲蓄不可能體會。

歐洲人早就意識到了這點(diǎn)，并且在1982 年歐洲郵電管理聯(lián)合會(CEPT)上形 成了移動通信特別研究組(GSM)來研發(fā)一個能在全歐洲大陸通用的移動通信系 統(tǒng)。提出的系統(tǒng)必須符合以下標(biāo)準(zhǔn)： 〃通話質(zhì)量好

〃終端及服務(wù)費(fèi)用低 〃支持國際漫游

〃能夠支持可隨身攜帶的終端 〃支持一系列新的服務(wù)和設(shè)備 〃效率高

〃與ISDN 兼容

1989 年，GSM 的責(zé)任轉(zhuǎn)移了到歐洲電信標(biāo)準(zhǔn)學(xué)院(ETSI)，并且GSM 規(guī)格的

第一階段也在1990 年出版了。商業(yè)服務(wù)在1991 年中期開始了，截至1993 年有 36 個GSM 網(wǎng)絡(luò)在22 個國家誕生了。GSM 不僅僅是歐洲標(biāo)準(zhǔn)，盡管它是在歐洲 規(guī)范化的?，F(xiàn)已有200 多個GSM 網(wǎng)絡(luò)在全球110 個國家和地區(qū)運(yùn)行。1994 年初 期全球有1,300,000 用戶，截至1997 年10 月已突破55,000,000 用戶。隨著美國

后來在GSM 領(lǐng)域制造了一個詞條PCS1900 作為GSM 的拓展,GSM 系統(tǒng)已發(fā)展至 各大洲,并且縮寫詞GSM 現(xiàn)在已可以代表移動通信的全局系統(tǒng)。

GSM 開發(fā)商選擇了一個當(dāng)時未經(jīng)證明的數(shù)字系統(tǒng)，與后來的標(biāo)準(zhǔn)模式蜂窩系 統(tǒng)相對，就象美國叫AMPS，而英國叫TACS 一樣。他們堅(jiān)信能夠推進(jìn)壓縮算法 和數(shù)字信號處理器使其能夠根據(jù)質(zhì)量和費(fèi)用將原始標(biāo)準(zhǔn)和系統(tǒng)連續(xù)改善。GSM 推薦8,000 頁設(shè)法使得在與供應(yīng)商競爭之中體現(xiàn)靈活性和創(chuàng)新，但提供 足夠的標(biāo)準(zhǔn)來保證在系統(tǒng)的組分之間適當(dāng)配合工作。完成提供功能和接口描述的 功能個體在系統(tǒng)中都有定義。

第一代系統(tǒng)是模擬的。上個世紀(jì)80 年代初期在歐洲迅速發(fā)展。雖然所有北 歐國家使用TACS 系統(tǒng)，英國和意大利使用NMT 系統(tǒng)，它們之間還有各式各樣 的系統(tǒng)不兼容。和這些系統(tǒng)相比，GSM 提供的更重要的第二代數(shù)字系統(tǒng)主要優(yōu)勢 體現(xiàn)在： 〃標(biāo)準(zhǔn)化； 〃容量； 〃質(zhì)量； 〃安全。

標(biāo)準(zhǔn)化保證了不同國家系統(tǒng)之間的兼容性，允許采取了數(shù)字化標(biāo)準(zhǔn)的國家的 訂戶使用他們自己的終端。在第一代系統(tǒng)中缺乏標(biāo)準(zhǔn)化的有限服務(wù)為在國家的邊 界之內(nèi)。流動性被改進(jìn)，漫游不再被限制到某一系統(tǒng)包括的面積之內(nèi)。既使當(dāng)用 戶從一個國家移動到另一個國家，電話也可以使用同一個個人號碼。因?yàn)榫W(wǎng)絡(luò)的功能元件和這些元素之間的接口被規(guī)范化，操作員可以從不同的 供營商購買。這意味著所有制造商的移動電話能與任何網(wǎng)絡(luò)溝通，即使這個網(wǎng)絡(luò) 是由不同的供營商的功能元件建立的。這為操作員和訂戶帶來費(fèi)用成本的降低。此外，電話費(fèi)用也降低了，因?yàn)镚SM 是國際標(biāo)準(zhǔn)，生產(chǎn)數(shù)量大，競爭水平高。能力方面，數(shù)字系統(tǒng)如GSM 比模擬系統(tǒng)使用的無線資源更有效。這意味著 更多的用戶可以使用同一頻帶。這就有可能利用先進(jìn)的數(shù)字技術(shù)，如語音壓縮算 法，信道編碼和多址接入技術(shù)。請注意，無線電頻率復(fù)用也取得了一定增益，這 也已用于模擬系統(tǒng)。頻率復(fù)用意味著同一載波可以在不同的地區(qū)重復(fù)使用。由于這種信道編碼方案，提高了可靠性及對噪音和其他用戶或系統(tǒng)的干擾能 力，數(shù)字傳輸系統(tǒng)的質(zhì)量更好了。質(zhì)量改進(jìn)的原因還在于改善了對無線連接的控 制，并適應(yīng)傳播條件下，使用先進(jìn)的技術(shù)，如電源控制或跳頻。質(zhì)量改進(jìn)的原因 還在于使用先進(jìn)的技術(shù)如電源控制或跳頻改善了無線連接的控制,，傳播條件的適

應(yīng)性等。這些將在下文中做更詳盡的解釋。

在安全方面，GSM 具有語音和數(shù)據(jù)通信的強(qiáng)大的認(rèn)證和加密技術(shù)的功能，保 證了保護(hù)接入網(wǎng)絡(luò)和保密性。

在移動通信系統(tǒng)中，一個最重要的因素就是頻譜。為了最有效地利用帶寬，系統(tǒng)設(shè)計(jì)的目的是通過基站的服務(wù)區(qū)到周邊小區(qū)，理論上是一個正六邊形。每個 小區(qū)有一個收發(fā)基站（BTS），其中，以避免相鄰小區(qū)的不同無線信道在運(yùn)行時 產(chǎn)生相互干擾。這樣可以在不相鄰的小區(qū)使用同一載頻。一組小區(qū)，作為一個整 體，給運(yùn)營商提供整個無線電頻譜是指一個區(qū)群。小區(qū)的形狀是不規(guī)則的，這取 決于是否有現(xiàn)成的基站，地理地形，無線電信號傳播中存在的障礙，等等。例如，在人口密集的城市地區(qū)，移動電話的通行非常重要，小區(qū)的直徑往往 會減小，以提高其通行能力。

這是允許的，因?yàn)橥活l道只在一個較小的地區(qū)內(nèi)使用。另一方面，小區(qū)直 徑的減小導(dǎo)致使用同一頻率的小區(qū)間的距離（即兩個公共通道小區(qū)間的距離）縮 小了，增強(qiáng)了各頻道之間的相互干擾。為了盡量提高抗干擾的能力，無線接口使 用了一系列技術(shù)。

一個基本的區(qū)群組織的結(jié)構(gòu)如圖1 所示。在這個例子中，我們看到了一個復(fù) 用模式的7 個不同的頻率，f1 至f7。這些頻率對應(yīng)于每個小區(qū)的信標(biāo)載波，整個

小區(qū)的信號信息就靠它們被傳播出去（見第2.7 節(jié)）。從圖中可以看出，某一載 波可在兩個不同的地理區(qū)域重復(fù)使用，只要這兩個地區(qū)離的足夠遠(yuǎn)，相互之間的 干擾足夠小。這一技術(shù)把地區(qū)分成小區(qū)和區(qū)群，經(jīng)營者可以利用有限的帶寬增加 覆蓋區(qū)域的面積。

第四篇：英文翻譯

School Profile

Jin Yuan Primary School was founded in 1966，and now it has 40 years? history.Thepredecessor of the school is ShiMian kuang Children Shool.In May 1993 ,It was placed under the Dalian Development Zone.In 2002, the new building was reconstruction in the school site.Now it occupies a total area of 18500 square meters, with a total construction area of 9020 square meters, it has got 30 class and 1478 students.Our school always adhere to the school mission-“To lay the foundation for the development of student life” and school

philosophy “To train the younger generation for adapting to the new society”.with “implementing quality education, making our school into modernization, distinctive characteristics, high-grade The 'people satisfaction' schools ”for the school mission and goals.Focusing on behavior, raising habits, pursuingdevelopment, hing research,benefit, the high quality;grasping

characteristics, treeing famous“ as the school ideas.”Innovation in operating a school, Distinctive Features,“ as the school way.Our school has been named the standardization of school facilities,education and management of Dalian advanced group, Green School of Dalian , big break in Dalianadvanced unit for physical education curriculum standard education health system,development zone course reform summary advanced unit, the characteristics of the development of school-based curriculum development awards such as prizes, Excellence Award and many other honors.In addition, teaching and research training center was also named the Development of information technology, sports, music, experimental point of school mental health disciplines.School emphasis on ”Science Education“, it has been named the Science and technology activities advanced units;land-sea model training base in Liaoning Province;Dalian Science and Technology Advanced Unit;advanced science and technology activities in Dalian youth units;The intelligent robot teaching activities carried out to further broaden the field of science teaching in recent years, we got soccer robot competition and the Youth Science and Technology Invention Contest winners many times in national, provincial and municipal.Our school was known by scientific and technological innovations, it has become a golden source of education and school characteristics of primary brand, and its fruitful results of educating people to win recognition of the higher education sector and social praise.Our school actively promoting international exchanges and cooperation.Based on the national culture, the students involved in multicultural perspective, let the student to have the ability to

communicate with different culture and cultural understanding

ability, feeling the other civilizations, inheriting Chinese culture, and for students build facing the world, developing yourself and

development of China's platform.At present,we have established the friendly and cooperative relations with Singapore, Britain and other countries of the schools.Our school is committed to the construction of educational information, establishing the educational information to promote the development strategy of modernization of school education.We was honored with the first model school education information by Dalian Municipal Bureau of Education.Physical education in our schoolis also flourished, we always adhere to the ”Sunshine Sports“ project.To ensure that every student at least one hour of exercise a day, each have a favorite sport, the school was named the physical education curriculum standards of Dalian advanced unit, DalianBig calisthenics demonstration school, Dalian”campus football

project“ Development of school.In recent years,school ?s sports teams in all kinds of various game had good performance , and it becomes the school?sbeautifulcard.Standing at a new starting point, facing the new century, we will try to”build multicultural education, reveal personality, improve

the educational grade, promote the connotation development" as our target, makes determined efforts, scientific planning, and strive to improve the level and constantly expand its reputation, trying to be the children paradise of JinYuan Primary School.

第五篇：英文翻譯

whether the university student should pay more atteion on studying or not ?the answer issure.First of all,during these time,we can touch more things,whichwehave not ever meet before and make a graetinflunce on our future life,If we don't handle it well,maybe we will lose a lot of thingswe adapt to sociaty more easily and more diffcult.we have time to play, but when you are playing and relaxing, dont forget the things you must do at school.school life is on of the best sections of your life.you need school life and time to learn and do things.