Inrecentyears,Israeliconsumershavegrownmoredemandingasthey’vebecomewealthierandmoreworldly-wise.Foreigntravelisanationalpassion;thissummeralone,onein10citizenswillgoabroad.Exposedtohigherstandardsofserviceelsewhere,Israelisarereturninghomeexpectingthesame.Americanfirmshavealsobegunarrivinginlargenumbers.ChainssuchasKFC,McDonald’sandPizzaHutaresettinganewstandardofcustomerservice,usingstrictemployeetrainingandconstantmonitoringtoensurethefriendlinessoffrontlinestaff.EventheAmericanhabitoftellingdepartingcustomersto“Haveaniceday”hascaughtonalloverIsrael.“Nobodywakesupinthemorningandsays,‘Let’sbenicer,’”saysItsikCohen,directorofaconsultingfirm.“Nothinghappenswithoutcompetition.”Privatization,orthethreatofit,isamotivationaswell.MonopoliesthatuntilrecentlyhavebeenfreetotaketheircustomersforgrantednowfearwhatMichaelPerry,amarketingprofessor,calls“therevengefulconsumer.”WhenthegovernmentopenedupcompetitionwithBezaq,thephonecompany,itsinternationalbranchlost40%ofitsmarketshare,evenwhileofferingcompetitiverates.SaysPerry,“Peoplewantedrevengeforalltheyearsofbadservice.”Theelectriccompany,whosemonopolymaybeshort-lived,hassuddenlymoppedrequiringuserstowaithalfadayforarepairman.Now,appointmentsarescheduledtothehalf-hour.ThegracelessElAlAirlines,whichisalreadyatauction,hasrestraineditsemployeestoemphasizeserviceandisboastingabouttheresultsinanadcampaignwiththeslogan,“Youcanfeelthechangeintheair.”Forthefirsttime,praiseoutnumberscomplaintsoncustomersurveysheets.3.IfsomeoneinIsraeltodayneedsarepairmanincaseofapowerfailure,________.

力的可传性原理适用于刚体，同样也适用变形体。

28、混凝土强度试验，试件尺寸愈大，强度愈高。（）

广播属于______通信系统

能量信号的自相关函数是_____函数。

功率信号的自相关函数和_________是一对傅里叶变换。

窄带高斯噪声的包络服从分布。

以下说法正确的是

同步解调中同步的含义是

对32路语音信号进行PCM时分复用编码，语音信号的抽样频率为8kHz，编码位数为8，则32路时分复用信号的总的二进制码元速率是_____波特。

PCM编码输入的抽样脉冲值为+1270个量化单位，用逐位比较反馈型编码器将其进行8位PCM编码后的量化误差是______个量化单位。

一个理想低通系统，无码间串扰的最高码元传输速率是系统带宽的_____倍，

当码组仅用于纠正错误时，若要求纠正t个错误，则最小码距是_____

根据香农信道容量公式，信号功率不变，信道带宽无限增大，信道容量也会无限增大。

符号间的统计相关性会使信源的平均信息量减小。