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Access count:#!/usr/bin/perl $log='counts.log'; $iplog='ips.log'; $lastip='lastip.log'; $host=$ENV{'REMOTE_ADDR'}; $path=$ENV{'DOCUMENT_URI'}||$ENV{'REQUEST_URI'}; print "Content-Type: text/html\n\n"; my $sameip=0; open(LASTIP,"+<$lastip"); flock(LASTIP,2); $lastrec=; ($lasthost,$lastpath,undef)=split(/\|/,$lastrec); if (($lasthost eq $host) && ($lastpath eq $path)){$sameip=1;} if ($sameip eq 0) { seek(LASTIP,0,0); truncate(LASTIP,0); $lastrec=join('|',$host,$path,"\n"); print LASTIP $lastrec; } flock(LASTIP,8); close(LASTIP); open(CNT,"+< $log"); flock(CNT,2); @count=; for($el=0;$el<=$#count;$el++) { ($ct,$rec,undef)=split(/\|/,$count[$el]); if($fnd=($path eq $rec)) { if ($sameip eq 0) {$count[$el]=join('|',++$ct,$rec,"\n");} else {$count[$el]=join('|',$ct,$rec,"\n");} last; } } push(@count,join('|',$ct='1',$path,"\n")) unless $fnd; seek(CNT,0,0); truncate(CNT,0); print CNT sort{($b=~/(\d+)/)[0]<=>($a=~/(\d+)/)[0]} @count; flock(CNT,8); close(CNT); print $ct; my $found=0; open(IPR,"< $iplog"); flock(IPR,1); while() { chomp; last if $found=($_ eq $host); } flock(IPR,8); close(IPR); unless($found) { open(IPW,">> $iplog"); flock(IPW,2); print IPW $host,"\n"; flock(IPW,8); close(IPW); }

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Selected Publications

Keyword(s): population models

[1]
H. T. Banks, L. W. Botsford, F. Kappel, and C. Wang. Modeling and estimation in size structured population models. In T. G. Hallam, L. J. Gross, and S. A. Levin, editors, Mathematical Ecology, pages 521–541, Singapoore, 1988. World Scientific Publ.

[2]
H. T. Banks and F. Kappel. Transformation semigroups and L1-approximation for size structured population models. Semigroup Forum, 38:141–155, 1989.

[3]
H. T. Banks, L. W. Botsford, F. Kappel, and C. Wang. Estimation of parameters in age/size structured population models. In M. Amouroux and A. El Jai, editors, Control of Distributed Parameter Systems 1989, pages 383–388, ..., 1990.

[4]
H. T. Banks, L. W. Botsford, and F. Kappel. Estimation of growth and survival in size-structured cohort data: An application to larval striped bass (morone saxatilis). J. Math. Biology, 30:125–150, 1991.

[5]
H. T. Banks, F. Kappel, and C. Wang. Weak solutions and differentiability for size structured population models. In W. Desch, F. Kappel, and K. Kunisch, editors, Estimation and Control of Distributed Parameter Systems, volume 100 of ISNM (International Series of Numerical Mathematics), pages 35–50, Basel, 1991. Birkhäuser.

[6]
K. Ito, F. Kappel, and G. Peichl. A fully discretized approximation scheme for size structured population models. SIAM J. Numerical Analysis, 28:923–954, 1991.
 
An efficient algorithm for computing solutions to a class of models for size structured populations is presented. Furthermore, some numerical examples are discussed.

[7]
F. Kappel and Kangpei Zhang. Approximation of linear age-structured population models using Legendre polynomials. J. Math. Anal. Appl., 180:518–549, 1993.
 
We develop a numerical algorithm for approximation of solutions for linear age–structured population models. The construction is based on approximation of age distributions by modified Legendre polynomials and uses the Trotter-Kato theorem of semigroup theory for the corresponding abstract Cauchy problem. Unbounded resp. nonintegrable mortality rates are admissible.

[8]
F. Kappel. Parameteridentification for state dependent delays originating from threshold conditions. In Proc. IEEE Mediterranean Symposium on New Directions in Control Theory and Applications, June 21 - 23, 1993, Crete Chandris Hotel, Maleme, Crete, Chania, 1993. Technical University of Crete.

[9]
H. T. Banks, F. Kappel, and C. Wang. A semigroup formulation of a nonlinear size-structured distributed rate population model. In W. Desch, F. Kappel, and K. Kunisch, editors, Control and Estimation of Distributed Parameter Systems: Nonlinear Phenomena, volume 118 of ISNM (International Series of Numerical Mathematics), pages 1–19, Basel, 1994. Birkhäuser.