Page 314 - Introduction to Statistical Pattern Recognition
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296                        Introduction to Statistical Pattern Recognition



                      4.   Repeat Projects  1 and 3 for various values of  I'  and k.  Plot 1MSE  vs.  I'
                           for the Parzen and ZMSE vs. k for the kNN.  Determine the optimal I' and
                           k experimentally.

                      5.   Repeat Experiment 1.
                      6.   Repeat Experiments 2 and 3.


                      Problems


                      1.   Prove that
                           (1)   Equation (6.3) is a density function, and
                           (2)  the covariance matrix of (6.3) is r2A.

                      2.   Find w of  (6.15) for the kernel function of (6.3).  Inserting m  = 1 and  00
                           into the w  obtained above, confirm that the w's  for normal and uniform
                           kernels are obtained.
                           [Hint:  r(E) + 1/& as E goes to zero.]

                      3.   Using  a normal  kernel, find  the  optimal  r*  and MSE*.  Compare them
                           with the optimal I-* and MSE* for a uniform kernel.

                      4.   Using  Ex { MSE { p(X) } }  instead  of  (MSE ( p(X) JdX, find  the  optimal  I'
                           and criterion value.  Use p (X) = Nx(O,I) and the uniform kernel.

                      5.   Derive the joint density function of coverages, ul , . . . ,up. Compute the
                           marginal density function of uk.

                      6.   Using  Ex (MSE { p(X)} }  instead  of  (MSE { p(X) )dX, find  the  optimal  k
                           and criterion value.  Use p (X) = Nx(O,l).

                      7.   Derive ExE{dkNN(X)} for the density function of  (6.3).  Inserting m  = I
                           and  00  to the above result, confirm that the averaged distances for normal
                           and uniform distributions are obtained.

                      8.   Compute  ExE ( dkNN(X) },  using  the  second  order  approximation
                           u  : + ar2/2).
                              pv(1
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