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1、<p><b>  西安郵電大學(xué)</b></p><p>  畢 業(yè) 設(shè) 計(論 文)</p><p><b>  外文文獻翻譯</b></p><p>  院(系): 自動化學(xué)院 </p><p>  專 業(yè): 智能科學(xué)與技術(shù)

2、 </p><p>  班 級: 智能0801班 </p><p>  學(xué)生姓名: 萬云艷 </p><p>  導(dǎo)師姓名: 韓中 職稱: 講師 </p><p>  起止時間:2012年 3月8日 至 20

3、12年 6月20日</p><p><b>  英文原文</b></p><p>  298 SHEARD AND MOSTASHARI</p><p>  Table I. Complex System Examples</p><p>  Systems Engineering DOI 10.1002/sy

4、s</p><p>  PRINCIPLES OF COMPLEX SYSTEMS FOR SYSTEMS ENGINEERING 299</p><p>  reason all should be amenable to improvement based on the principles for engineering complex systems addressed

5、in later sections. Systems engineers should be familiar with the three examples:</p><p>  ?·INCOSE </p><p>  ·The systems engineering (SE) process within a company </p><p&g

6、t;  ·The National Airspace System (air traffic control system). </p><p>  Table I shows that all three examples have all complex systems attributes listed above and therefore that these are complex syst

7、ems.</p><p>  3.2. Systems-of-Systems</p><p>  It should be noted that Systems-of-Systems (SoSs) is currently of great interest to systems engineers. The topic was originally defined by [Maier,

8、1998]; confer-ences and papers addressing systems-of-systems have increased greatly in the last few years. Systems-of-sys-tems issues that differ from systems issues include:</p><p>  Integration of independ

9、ently-operational compo-nent systems that were built for other purposes </p><p>  ?Rapid evolution of both user needs and system technologies, which prevents stable requirements </p><p>  ?Mul

10、tiple disparate stakeholders with conflicting needs and a lack of incentives to participate in the system-of-systems </p><p>  ?Distributed development and its consequent com-munication problems </p>

11、<p>  Dependence on an integrated computing infra-structure that has extremely high and increasing complexity, thus threatening unintended conse-quences. </p><p>  In an engineering context, systems-of

12、-systems are often, but not always, complex systems. Figure 2 shows this comparison. Systems-of-systems usually come up in a program acquisition context, and are distinguished as being unmanageable using standard top-tow

13、n sys-tems engineering, whereas complex systems usually come up in an analytical or scientific context, and are described as being not decomposable.</p><p>  Most systems-of-systems are also complex systems

14、(CxSs) and vice versa; hence the two top circles overlap greatly. A system such as Joint Strike Fighter that is developed via a program manager and a chief engineer is by definition not a complex system (there are not in

15、dependent agents). However, it specifically is consid-ered a system-of-systems in some Defense Department work [Chairman, Joint Chiefs of Staff, 2007], although not according to the more generally accepted definition [DO

16、D AT&L, 200</p><p>  4. COMPLEX SYSTEMS SCIENCE INSIGHTS</p><p>  Complex systems science includes a number of current research areas all having to do in some ways with complexity, complex s

17、ystems, or nonlinear systems. Some examples include complexity theory, chaos the-ory, cellular automata, and nonlinear dynamics. Taken as a whole, these sciences offer the following insights, which have important systems

18、 engineering potential [Sheard, 2006]:</p><p>  Emergence: Emergence is related to the depend-ence of the whole on parts, the interdependence of parts, and specialization of parts. While study-ing the parts

19、in isolation does not work, the nature of complex systems can be probed by investigat-ing how changes in one part affect the others, and the behavior of the whole. </p><p>  Pattern formation: Simple mathema

20、tical mod-els capture pattern formation such as local activa-tion / long range inhibition. </p><p>  Multiple (meta-) stable states: Small displace-ments (perturbations) lead to recovery, and larger ones can

21、 lead to radical changes of properties. Dynamics do not average simply. </p><p>  Multiscale descriptions are needed to under-stand complex systems. Fine scales influence large scale behavior. </p>&l

22、t;p>  It is difficult but not impossible to answer the question “How complex is it?” </p><p>  Behavior (response) complexity: To describe the behavior of a system we try to describe the re-sponse functio

23、n: actions as a function of the en-vironment. However, unless simplifying assumptions are made, this requires an amount of information that grows exponentially with the complexity of the environment. </p><p>

24、;  Contrasts: Complex systems often exhibit con-trasting characteristics, including simplicity and complexity, order and disorder, random and pre-dictable behavior, repeating patterns and change.</p><p>  We

25、 cannot predict what a complex system will evolve into. </p><p>  The complex adaptive systems cycle, created by Gell-Mann [1994a], is shown in the first column of Table II. The other three columns show how

26、our exam-ple systems evolve in accordance with this cycle.</p><p>  The first step in the cycle is abstracting from the real world to a model. This involves a tradeoff between fine-graining and coarseness. T

27、he second step is iden-tifying regularities or patterns in the abstracted infor-mation. It is often difficult to sort out what is random from what is informative or patterns. The third step is organizing these regulariti

28、es into a schema. This essentially compresses the information into something sim-pler; how much compression is acceptable is a judg-ment call</p><p>  It is worthwhile to note that in explaining this cycle,

29、Dr. Gell-Mann [1994b] was concentrating on biological systems rather than on systems engineered by man, so the applicability of the cycle to man-made complex systems is suggestive of a general truth.</p><p>

30、  300 SHEARD AND MOSTASHARI</p><p>  Figure 2. Systems of systems compared to complex systems. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]</p&g

31、t;<p>  Table II. Complex Adaptive Systems Cycle Applied to Examples</p><p><b>  中文譯文</b></p><p>  298 謝爾德和莫斯塔沙瑞</p><p>  表格一:復(fù)雜系統(tǒng)的例子</p><p>  復(fù)雜系

32、統(tǒng)系統(tǒng)工程的原理 299</p><p>  原因都應(yīng)該服從改善為基礎(chǔ)的原則,在后面的章節(jié)中涉及的復(fù)雜的系統(tǒng)工程。系統(tǒng)工程師應(yīng)該熟悉的三個例子:</p><p><b>  ·國際系統(tǒng)工程協(xié)會</b></p><p>  ·在公司內(nèi)系統(tǒng)工程(SE)的過程</p><p>  ·國家空域系統(tǒng)(

33、空中交通管制系統(tǒng))。</p><p>  表一顯示,所有三個例子,所有復(fù)雜的系統(tǒng)屬性中列出以上,因此,這些都是復(fù)雜的系統(tǒng)。</p><p><b>  3.2.系統(tǒng)的系統(tǒng)</b></p><p>  應(yīng)當(dāng)指出的系統(tǒng)系統(tǒng)(SOSS)是目前系統(tǒng)工程師的極大興趣。最初定義的主題[1998]邁爾;賦予差異和文件處理系統(tǒng)的系統(tǒng)已經(jīng)在過去幾年中大大增加。&

34、#160;SYS-TEMS系統(tǒng)的問題,從系統(tǒng)的問題不同,包括:</p><p>  獨立運作的組分NENT被用于其他目的的系統(tǒng)集成</p><p>  快速演變的用戶需求和系統(tǒng)技術(shù),從而防止了穩(wěn)定的需求</p><p>  矛盾需要多個不同的利益相關(guān)者和缺乏激勵機制,參與系統(tǒng)的系統(tǒng)</p><p>  分布式的發(fā)展和其隨后的通信問題</

35、p><p>  綜合計算基礎(chǔ)結(jié)構(gòu),具有極高的和日益復(fù)雜的依賴性,從而威脅的意外conse-序列。 在工程方面,往往是系統(tǒng)的系統(tǒng),但并不總是,復(fù)雜的系統(tǒng)。圖2顯示了這種比較。系統(tǒng)的系統(tǒng)通常會在收購方案方面,為無力,使用標(biāo)準(zhǔn)的頂級鎮(zhèn)SYS-TEMS工程,而復(fù)雜的系統(tǒng)通常在分析或科學(xué)方面的區(qū)別,不腐化。</p><p>  大多數(shù)系統(tǒng)的系統(tǒng)也復(fù)雜系統(tǒng)(CxSs),反之亦然,因此前兩個圓圈重疊大大。如

36、聯(lián)合攻擊戰(zhàn)斗機的系統(tǒng)開發(fā),通過項目經(jīng)理和總工程師,是不是一個復(fù)雜的系統(tǒng)(有沒有獨立的代理人)的定義。然而,它專門consid-ERED等效1系統(tǒng),系統(tǒng)在一些國防部署工作[主席,參謀長聯(lián)席會議,2007],雖然未按更普遍接受的定義[國防部的AT大號,2006],這是更為像梅爾定義。特設(shè)系統(tǒng),系統(tǒng)在長周期自上而下開發(fā)的系統(tǒng)相比,被拉到一起在最后一分鐘由操作人通道,并沒有首席系統(tǒng)集成商,也不是一個特定的發(fā)展時期[摩天輪,2006年]。這些最沒

37、有資格作為復(fù)雜的系統(tǒng)。復(fù)雜的系統(tǒng),包括大量的基本粒子,或者是不相關(guān)的,以工程的生物系統(tǒng)將不被視為系統(tǒng)的系統(tǒng)。</p><p>  4.科學(xué)洞察復(fù)雜系統(tǒng)復(fù)雜系統(tǒng)的性質(zhì),可以探測由investigat的一部分變化是如何影響他人,而全的行為。復(fù)雜系統(tǒng)科學(xué)包括了目前的研究領(lǐng)域都不必做某些方面的復(fù)雜性,復(fù)雜系統(tǒng),非線性系統(tǒng)的數(shù)量。一些例子包括復(fù)雜性理論,混亂理論,元胞自動機,非線性動力學(xué)。作為一個整體,這些科學(xué)提供了以下的

38、看法,其中有工程的重要系統(tǒng)的潛力[謝爾德,2006]: 興起的出現(xiàn),是取決于整個ENCE的部件,零件的相互依存關(guān)系,以及零件的??專業(yè)化。雖然學(xué)習(xí)ING在隔離的部分不起作用。</p><p>  格局的形成:簡單的數(shù)學(xué)模ELS捕捉格局的形成,如本地激活/抑制遠距離。 多(元)穩(wěn)定狀態(tài):小位移(擾動)導(dǎo)致的復(fù)蘇,并可能導(dǎo)致更大的徹底改變物業(yè)。動力學(xué)不要簡單平均</p><p>  多尺度

39、描述下復(fù)雜系統(tǒng)的需要。細密的鱗片影響大規(guī)模的行為。</p><p>  它是很難的,但不是不可能回答的問題“,它是多么復(fù)雜?”</p><p>  行為(響應(yīng))的復(fù)雜性:為了描述一個系統(tǒng),我們嘗試來形容再響應(yīng)函數(shù)的行為:作為一個功能的連接環(huán)境的行動。然而,除非作出簡化假設(shè),這需要一個信息量成倍增長與環(huán)境的復(fù)雜性。</p><p>  對比:復(fù)雜系統(tǒng)往往表現(xiàn)出CON-

40、trasting的特點,包括簡單和復(fù)雜性,秩序和無序,隨機行為,重復(fù)圖案和變化。</p><p>  我們無法預(yù)測什么將演變成一個復(fù)雜的系統(tǒng)。</p><p>  復(fù)雜自適應(yīng)系統(tǒng)循環(huán),由蓋爾曼創(chuàng)造的[1994a],在第一列的表二所示。其他三個列顯示我們的考試例如系統(tǒng)如何按照這個周期的演變。</p><p>  在循環(huán)的第一步是從現(xiàn)實世界的抽象模型。這涉及到一個精細的

41、木紋和粗糙之間的權(quán)衡。第二步是在抽象的信息信息的IDEN-tifying規(guī)律或模式。它往往是很難弄清楚什么是隨機的,什么是信息或圖案。第三步是組織架構(gòu)到這些規(guī)律。這實質(zhì)上是壓縮成SIM簡單的信息是判斷MENT通話的壓縮是可以接受的。第四步是確定這說明一些變化。在現(xiàn)有的復(fù)雜系統(tǒng)的分析,這可能意味著分組已經(jīng)注意到的變化。在創(chuàng)建復(fù)雜的系統(tǒng),這可以是故意,不同的元素。使用的模式是指驗證現(xiàn)實世界。最后,現(xiàn)實世界的壓力造成的圖式,在大多數(shù)情況下,最

42、有意義的選擇。</p><p>  值得一提的是,在解釋這個周期,蓋爾曼博士[1994b]對生物系統(tǒng),而不是集中在由人設(shè)計的系統(tǒng),所以周期的人造復(fù)雜系統(tǒng)的適用性,是一個普遍的真理暗示。</p><p>  300 謝爾德和莫斯塔沙瑞</p><p>  圖2。系統(tǒng)比較復(fù)雜的系統(tǒng)。[彩色圖,可以被視為在網(wǎng)上發(fā)行,這是在www.interscience.wiley

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