1、上海海事大学信息工程学院上海海事大学信息工程学院Unit 2 Simulation of Random VariablesnWords and expressionsnText and notesnGrammarnExercisesnReading material上海海事大学信息工程学院上海海事大学信息工程学院Words and expressionsnAdvocate n.主张者,赞成者nAlternativeadj.另一个可选择的nArgumentn.自变量nConcentrationn.集中,集合,浓缩nConvergev.收敛(n.convergence)nDeficiencyn.缺
2、乏,不足nDerivativen.导数nDien.骰子nDifferentiableadj.可微分的nDispersev.(使)分散,(使)散开,疏散nFacilityn.设备,工具上海海事大学信息工程学院上海海事大学信息工程学院Words and expressionsnHistogramn.直方图nInferencen.推论nInterpretationn.说明,解释nProfilen.剖面,侧面,外形,轮廓nProportionn.比例nPseudo-random adj.伪随机的nRefractionn.折射nStabilizev.稳定(n.stabilization)nStatist
3、icaladj.统计的,统计学的nStochasticadj.随机的nSuccessiveadj.连续的上海海事大学信息工程学院上海海事大学信息工程学院Words and expressionsnTossv./n.投,掷nUnderliev.位于之下,成为的基础nBy means of 依靠nConsist of 由组成nGive rise to 引起,使发生nIn contrast with 和形成对比对照nIn terms of 根据,按照,用的话,在方面nBernoulli distribution 伯努利分布nBinomial distribution 二项式分布nNormal dis
4、tribution 正态分布nPoisson distribution 泊松分布nProbability density function概率密度函数(abbr.pdf)nUniform distribution均匀分布上海海事大学信息工程学院上海海事大学信息工程学院Text and notesnThis article is about random variables.It include three parts:Interpretations of probabilityRandom variables:definition;discrete random variables;conti
5、nuous random variablesRandom variables for simulation上海海事大学信息工程学院上海海事大学信息工程学院Text and notesnThis concept of probability is of an objective quantity that applies to each observation and measure(in a relative way)how likely it is to fall into the corresponding class.n概率的这种定义是客观的,它应用于每次观测,并以一种概率的这种定义是客
6、观的,它应用于每次观测,并以一种相对的方式度量其结果归入相应类别的可能性。相对的方式度量其结果归入相应类别的可能性。上海海事大学信息工程学院上海海事大学信息工程学院Text and notesnIt seems that one is forced into a subjective view of the uncertainties,but the probability figures that emerge must obey certain rules in order to be consistent.n看来,人们对这种不确定性陷入了自己的主观判断中,但看来,人们对这种不确定性陷入了
7、自己的主观判断中,但是由此产生的概率必须遵循某些准则以保持一致性。是由此产生的概率必须遵循某些准则以保持一致性。上海海事大学信息工程学院上海海事大学信息工程学院Text and notesnFor engineering students it is most appropriate to keep the first interpretation-that of probability as an idealized proportion-in mind when studying the theory.n对于工科学生,学习概率时应谨记,概率就是理性的比例。对于工科学生,学习概率时应谨记,概
8、率就是理性的比例。上海海事大学信息工程学院上海海事大学信息工程学院Text and notesnThis may seem a hopeless requirement,considering that computer programs are sequences of deterministic instructions running on deterministic hardware.n由于计算机程序是在确定的硬件上运行的确定的指令,这由于计算机程序是在确定的硬件上运行的确定的指令,这似乎是个奢求。似乎是个奢求。上海海事大学信息工程学院上海海事大学信息工程学院Text and note
9、snThe successive variables appear to be uncorrelated,and,although there is some structure in the sequence(and indeed the sequences will eventually repeat itself),it is rare for these deficiencies to cause problems in practice.n序列序列 中的元素看似互不相关,尽管在序列中的元素看似互不相关,尽管在序列中存在某些结构(该序列最终的确重复),但是这并中存在某些结构(该序列最终
10、的确重复),但是这并不影响实际应用。不影响实际应用。12,U U 12,U U 上海海事大学信息工程学院上海海事大学信息工程学院Grammar专业英语词汇的构成n许多单词在普通英语中的意义与在专业英语中的意义相差许多单词在普通英语中的意义与在专业英语中的意义相差很大很大n专业词汇(专业词汇(Technical words):histogram,probability,oscillatorn半专业词汇半专业词汇(semi-technical words):carrier(载波,载流载波,载流子,载重架,载体,吸收剂子,载重架,载体,吸收剂)n非专业词汇非专业词汇(non-technical wo
11、rds):application,implementation,yield etc.n很多专业词汇符合构词法:派生、复合、转化、缩略、拼很多专业词汇符合构词法:派生、复合、转化、缩略、拼缀等。缀等。上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)n在原有词根的基础上加前缀或后缀:在原有词根的基础上加前缀或后缀:n常用前缀:常用前缀:na-:不,无 asymmetry,asynchronousnanti-:反抗、防止anti-clockwisenco-:共同、相互cooperation,correlationndis-:不,除disadvantage,disco
12、vernen-/em-:使enable,enlarge,embed,embody(包含,收录)nim-/il-/in-/ir-:不imbalance,illegible,incorrect,irregularnInter-:在之间,相互interchange,interface,internet,interactnmis-:不,失miscount,mistake上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)nmulti-/poly-:多multipurpose,polynomial(多项式)nnon-:非、不nonlinear,nondestructiven
13、post-:后postgraduate,posteriornpre-:预先preset,prefacenre-:再、反、重新reaction,readjust,reversensub-:次于、在下subroutine(子程序),subscriptnsuper-:超,在上superconductor,superposition(重合,叠加)nsym-/syn-:相同symmetry,synchronousntele-:远离telephone,telegraphntrans-:跨、移transmitter,transverse(横),transformnultra-:外、极、超ultrasonic
14、(超声波),ultraviolet ray(紫外线)nun-:不unable,unavoidable,unstable上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)n常用表示数量关系表示数量关系的前缀:npico-:10-12ppicofaradnnano-:10-9n nanometernmicro-:10-6 microhenrynmilli-:10-3mmillisecondnkilo-:103 kkilogramnmega-:106Mmegahertzngiga-:109Ggigabytesnsemi-/hemi-:半semiconductor,he
15、mispherenuni-/mon-:一monotone,uniformnbi-/di-/ambi-/twi-:二bilateral,diode,ambiguous,twilightntri-:三triangle,tripodnquadr-:四quadruplenoct-:八octagonndeca-:十decade上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)n常用后缀:常用后缀:n-ance/-ancy/-cy/-ence/-ency:表示情况、性质、状态、程度等:inference,resistance,efficiency,accuracyn-er/
16、-or:表示人或物:amplifier,conductor,researchern-ic(s):学科、学术:logic,electronicsn-tion/-sion/-ing:表示动作及其过程、状态和结果:distribution,conclusion,readings,recordingsn-ist:表示人:scientist,specialistn-ity:表示性质、程度等:probability,uncertaintyn-ment:表示动作、状态等:measurement,developmentn-ture:表示性质、状态等:mixture,temperaturen-ness:形容词名
17、次后缀:hardness,robustness上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)n常用后缀:常用后缀:n-able:表示可能性:differentiable,countable,controllablen-cal/-ical:表示性质:statistical,atomic,typicaln-ant/-ent:表示状态、性质:convergent,important,independentn-ary:与有关的:circular,secondaryn-ed:已的,被的:reduced,treated,refined,developedn-ive:表示
18、性质、状态等:objective,relative,effectiven-ful:充满的:plentiful,usefuln-less:没有,无:useless,countlessn-ous:有性质的:numerous,various上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)n常用后缀:常用后缀:n-en:使变成:harden,broadenn-ize/-ise:使成为:modernize,stabilizen-fy:使成为.:classify,verifyn-ly:地:closely,likely,imperfectly,monthlyn-ward(s
19、):表示方向:backwards,upwardsn-wise:表示方式、方向:clockwise,likewise上海海事大学信息工程学院上海海事大学信息工程学院1、派生法(Derivation)n常用词根:常用词根:naudi-:听见,听:audibility,audiphone(助听器)nauto-:自动,自己:automation,autopilot(自主导航,自主驾驶)n-free:无:rustfree(防锈的)n-fold:倍:multifold(多种多样的,重叠的)n-gram/-graph:记录、写、文字、图形等:spectrogram(光谱图),telegram,spectro
20、graph(光谱仪)n-graphy:图像学:photography(摄影学)n-meter:仪表、仪器:tachometer(转速仪)n-ology:学科:biology,geologyn-phone:声音:microphone,telephonen-proof:防:waterproof,n-scope:观测仪:telescopen-tight:密、不透:airtight上海海事大学信息工程学院上海海事大学信息工程学院2、复合法(composition)n由两个或两个以上词汇按照一定顺序排列构成新词。Trial and error(反复试验);Q-factor;allowable error
21、(允许误差)直接结合直接结合:breakthrough,overestimate,bandwidth连字符连字符:general-purpose(多用途的),state-of-the-art(达到最新技术发展水平的)上海海事大学信息工程学院上海海事大学信息工程学院3、转化法(conversion)n词性转换词性转换,转换后与原来的意义有密切联系:function,sound,ground,use,record,increase,research,subject etc上海海事大学信息工程学院上海海事大学信息工程学院4、拼缀法(blending)n以原有的两个或者两个以上词为基础,经过首尾剪裁,
22、重新组合成新词:Transistor=transfer+resistor modem=modulator+demodulator上海海事大学信息工程学院上海海事大学信息工程学院5、缩略法(shorting)n以几个单词的首字母组合在一起成为一个新词,多用于专有名词Radar(radio detection and ranging)雷达GPS(global positioning system)全球定位系统上海海事大学信息工程学院上海海事大学信息工程学院代词常用方法n物主代词作定语时所表示的主谓(主表)关系和物主代词作定语时所表示的主谓(主表)关系和动宾关系动宾关系主谓关系:被修饰的名词多数来自
23、不及物动词和形容主谓关系:被修饰的名词多数来自不及物动词和形容词词This machine was limited in speed by its use of relays(继电器)rather than electronic devices.Physics is the most quantitative of the sciences,and we must become accustomed to its insistence upon accurate measurements and precise relationships if we are to appreciate its
24、 results.上海海事大学信息工程学院上海海事大学信息工程学院代词常用方法动宾关系:被修饰的名词必定来自于及物动词动宾关系:被修饰的名词必定来自于及物动词The questions of convergence are not simple,and their study forms an important chapter in modern analysis.Many scientists have worked at the theory of magnetism since its discovery.上海海事大学信息工程学院上海海事大学信息工程学院代词常用方法n代词代词one的一
25、个特殊用法的一个特殊用法n在科技文中表示在科技文中表示“有人、人们、大家有人、人们、大家”这一概念这一概念时,一般是不用时,一般是不用people这个词,多数英美科技工这个词,多数英美科技工作者通常使用被动语态或者用作者通常使用被动语态或者用one作主语的主动作主语的主动语态语态nBy the“most efficient”algorithm one normally means the fastest.nIf one wishes to detect objects,the radar transmitter may be used.上海海事大学信息工程学院上海海事大学信息工程学院代词常用方
26、法n用用it,its,they,their等代词来代替句中的人等代词来代替句中的人或物或物nBefore it can work,a computer must be told what to do.nBecause of its capacity to handle large volumes of data in a very short time,a computer may be the only means of resolving problems when time is limited.上海海事大学信息工程学院上海海事大学信息工程学院上海海事大学信息工程学院上海海事大学信息工程
27、学院句子练习句子练习n根据系统的幅频特性曲线,我们得出结论,该系统是带通滤波器。n第二节介绍了该领域的研究现状。n深度学习的概念源于人工神经网络的研究,其概念由Hinton等人于2006年提出。上海海事大学信息工程学院上海海事大学信息工程学院上海海事大学信息工程学院上海海事大学信息工程学院常用数学公式的表达与读法n科技文献中常有大量的数学公式,表达定量关系。n常用数学公式表示与读法A posternPoster of Crowd saliency (ECCV2014)上海海事大学信息工程学院上海海事大学信息工程学院听力训练nVOA news:Google Self-Driving Car He
28、ading to Public Streets上海海事大学信息工程学院上海海事大学信息工程学院Exercises1.Choose the best answer for each of the following questions.(1)The theoretical foundation for the subject of statistics is contained in .a.histogramb.the concept of probabilityc.the theory of probabilityd.decision-making and expert system上海海事大
29、学信息工程学院上海海事大学信息工程学院cExercises(2)For engineering students it is most appropriate to keep the first interpretation that of probability as an idealized proportion in mind when studying the theory.What does“that”mean in the sentence?.a.theoryb.conceptc.interpretationd.study上海海事大学信息工程学院上海海事大学信息工程学院cExerc
30、ises(3)Find which is not an example of random variables .a.the number of students attending classb.the number of bits used to denote ASCII codesc.the lifetime of a batteryd.the waiting time at the crossroad上海海事大学信息工程学院上海海事大学信息工程学院bExercises(4)In general,the behavior of a continuous random variable i
31、s described by a .a.distribution functionb.probability functionc.probability distributiond.probability density function上海海事大学信息工程学院上海海事大学信息工程学院dExercises(5)Random variables with different distributions can be generated .a.by Monte Carlo numerical methodsb.from an Gaussian distributed random sequence
32、c.from uniformly distributed pseudo-random sequenced.based on the central limit theorem上海海事大学信息工程学院上海海事大学信息工程学院cExercises2.Match the word pairs,one from Column A and one from Column B.Column AColumn Bputere.function6.samplef.variable7.statisticalg.distribution 8.impossibleh.event9.standardi.system 1
33、0.relativej.inference上海海事大学信息工程学院上海海事大学信息工程学院Exercises3.Translate the following sentences into Chinese.(1)A lot of information is required to specify the exact distribution of a random variable,and even more to specify the joint distribution of two or more variables.(2)The binomial and Poisson are d
34、iscrete distributions,which have the widest applications among all discrete random variables.The probability distribution is especially useful to engineers because of its importance in statistical quality control.上海海事大学信息工程学院上海海事大学信息工程学院Exercises3.Translate the following sentences into Chinese.(3)Fo
35、r any random variable the difference between the values of the distribution function at two pints is the probability that a value of the random variable will lie between those two points(or is equal to the upper one).(4)In general,the probability p of a random event can be interpreted as meaning tha
36、t if the experiment is repeated a large number of times,the event would be observed about 100p percent of the time.上海海事大学信息工程学院上海海事大学信息工程学院Exercises3.Translate the following sentences into Chinese.(5)In statistics it is customary to refer to any process of observation as an experiment.(6)If an event
37、 definitely cannot occur upon realization of the set of conditions it is called impossible.上海海事大学信息工程学院上海海事大学信息工程学院Exercises4.Complete the sentences.You may have to change some words slightly.(1)_ is the study and use of electrical devices that operate by controlling the flow of _ or other _ charged
38、 particle in devices such as vacuum tube and semiconductors.a.electronb.electronicc.electronicsd.electronically上海海事大学信息工程学院上海海事大学信息工程学院ElectronicselectronelectronicallyExercises(2)One of the best known computer _ which are very widely used in research,design and training is the flight _ upon which p
39、ilots receive much of their training.a.simulationb.simulatorc.simulatingd.simulate(3)Signals are sent to _ to _.a.amplificationb.amplifierc.amplifyingd.amplify上海海事大学信息工程学院上海海事大学信息工程学院simulationsimulatoramplifiersbe amplifiedExercises(4)(a)It follows that we can use the one table for the standard nor
40、mal for all calculations involving normal _.(b)However,a great many applications of probability theory concern quantitative _ rather than qualitative events.(c)There are two approaches to measuring the _ of random variables around their central values.The most important such measure is the _,a weigh
41、ted sum of sequential differences between the possible values and the mean.上海海事大学信息工程学院上海海事大学信息工程学院variatesvariablesvariationvarianceExercises(d)Frequency response will be flat and bandwidth infinite because AC will be simply a rapidly _ DC level to the ideal amplifier.a.variousb.variablec.variated.
42、variancee.variationf.varying上海海事大学信息工程学院上海海事大学信息工程学院varying上海海事大学信息工程学院上海海事大学信息工程学院Reading materialnThe central limit theoremnTwo parts:1.The normal distribution 2.The central limit theorem上海海事大学信息工程学院上海海事大学信息工程学院New wordsnApproximation近似值nArbitrary任意的nCumulative累积的nMean均值nParameter参数nPopulation总体nR
43、obust稳定的,(-ness,鲁棒性,稳定性)nSymmetrical对称的,均匀的(名词 symmetry)nTabulate把制成表格,列数nVariance方差nVariate变量nIndependent identically distributed 独立同分布(abbr.i.i.d.)nStandard deviation 标准偏差nStandard normal distribution 标准正态分布(均值为0,方差为1)nStatistical inference 统计推理上海海事大学信息工程学院上海海事大学信息工程学院AssignmentnDo exercises 1,2,3
44、 and 4 in page 23;nRead the reading material.nNote:this passage is related with the probability theory which you will study.上海海事大学信息工程学院上海海事大学信息工程学院电子信息领域常用缩略词汇总(1)nCPU:central processing unitnROM:read-only memorynRAM:random access memorynCDMA:Code Division Multiple AccessnGPS:Global Position System
45、nGPRS:General Packet Radio ServicenSNR:Signal Noise RationDSP:Digital Signal ProcessingnDIP:Double In-line PackagenIC:Integrated CircuitnPCB:Print Circuit BoardnGSM:Global System of Mobile CommunicationsnEDA:Electronic Design Automation上海海事大学信息工程学院上海海事大学信息工程学院Further reading materialnOmar Y.Al-Jarraha,Paul D.Yoob,Sami Muhaidatc et.al.Big Data Research 2(2015),87-93nEfficient Machine Learning for Big Data A Review