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Modifications  of  BME  Analysis             167



         (c) Th e health  damage  indicator   of a  populatio n




         where  B(p k)  is  the  density  of  receptors  in  the  neighborhood  of  V(p k),  and
         X(p k)  is a specified  health  effect  (see  "Human-exposure systems"  on p.  182).
             In the functional  case of Equation  9.1,  the  basic equations of BME analysis
         are  easily  modified  as follows.  The  Lagrange multipliers ^ a are the  solutions
         of the  system  of  moment  equations





         where XA 's a realization of the functional random field (Eq. 9.1); the
         BMEmode  equation  is





         and  the  posterior  pdf  is




         where                  The form  of the ^-operator  in  Equations 9.6 and
         9.7 depends on the  knowledge available.  In the  case of the  knowledge described
         in  Proposition  6.1 (p.  126),  the ^-operator  has the form  used  in Equation  6.1
         (p.  126);  then,  Equations 9.6 and 9.7 reduce to





         and



             The g a's  are now functions  of the  point  and the  functional  random fields
         (e.g., they  may include point and block covariances and point-block  covariances
         as well).  The  analysis  can  be generalized in  terms  of  the  operators shown  in
         Table  6.1  (p.  133)  or  any other  posterior  operator available.

         EXAMPLE  9.1:  The  average  ozone  exposure  XT  =  E  during  each day was
         calculated from  Equation  9.3 for a geographical  region  in the  eastern  U.S. that
         includes  New York  City  and  Philadelphia.  It  was assumed  that  r e  =  24  hr,
         / e  =  100%,  and X  =  E\-h  is the  1-hr  ozone  exposure  (in  ppm).  In  Figure
         9.1,  the  temporally  averaged  1-hr  ozone exposure maps  are plotted  for  a few
         selected  days  in  July  of  1995.  These  maps  can  help  us detect  variations  in
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