Page 466 - Thomson, William Tyrrell-Theory of Vibration with Applications-Taylor _ Francis (2010)
P. 466

Chap. 13   Problems                                            453


                              13-7  Determine  the  mean  and  mean  square values for the  rectified  sine wave.
                              13-8  Discuss  why  the  probability  distribution  of  the  peak  values  of  a  random  function
                                   should  follow the  Rayleigh distribution or one  similar in  shape  to it.
                              13-9  Show  that  for  the  Gaussian  probability  distribution  p{x),  the  central  moments  are
                                   given by

                                               £(x")  =  r   x^p(x)dx
                                                       —QO

                                                        0                  for n odd
                                                        1  •  3  •  5  ’ • •  (/t  -   l)o-"   for n  even

                              13-10  Derive  the  equations  for  the  cumulative  probability  and  the  probability  density
                                   functions of the  sine wave.  Plot these  results.
                              13-11  What  would  the  cumulative  probability  and  the  probability  density  curves  look  like
                                   for the rectangular wave  shown  in  Fig.  P13-11?


                                            Ml


                                                                 J   Figure P13-11.


                              13-12  Determine  the  autocorrelation of a cosine wave  x(t) = A cos t,  and plot it against  r.
                              13-13  Determine  the  autocorrelation  of the rectangular wave  shown  in  Fig.  P13-13.


                                                    y
                                                   A

                                                    0    TT   2 n
                                                                     Figure P13-13.


                              13-14  Determine  the  autocorrelation  of the  rectangular pulse  and plot  it  against  r.
                              13-15  Determine  the  autocorrelation  of the binary  sequence  shown  in  Fig.  P13-15.  Sugges­
                                     .
                                   tion’  Trace  the wave on  transparent  graph paper and shift  it  through  r.



                             0  1  2 3 4 5 6 7 8 9  10  II  12    t   Figure P13-15.

                              13-16  Determine  the  autocorrelation  of the  triangular wave  shown  in  Fig.  P13-16.
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