第一次latex编译文件，出现一下错误：

latex a.tex
This is pdfTeX, Version 3.1415926-2.5-1.40.13 (TeX Live 2013/dev)
 restricted \write18 enabled.
entering extended mode
(./a.tex
LaTeX2e <2011/06/27>
Babel and hyphenation patterns for english, dumylang, nohyphenation, lo
aded.
(./IEEEtran.cls
Document Class: IEEEtran 2007/03/05 V1.7a by Michael Shell
-- See the "IEEEtran_HOWTO" manual for usage information.
-- http://www.michaelshell.org/tex/ieeetran/
-- Using IEEE Computer Society mode.
(/usr/share/texlive/texmf-dist/tex/latex/psnfss/ot1ppl.fd)
kpathsea: Running mktextfm pplr7t
/usr/share/texlive/texmf/web2c/mktexnam: Could not map source abbreviation  for pplr7t.
/usr/share/texlive/texmf/web2c/mktexnam: Need to update ?
mktextfm: Running mf-nowin -progname=mf \mode:=ljfour; mag:=1; nonstopmode; input pplr7t
This is METAFONT, Version 2.718281 (TeX Live 2013/dev)


kpathsea: Running mktexmf pplr7t
! I can't find file `pplr7t'.
<*> ...:=ljfour; mag:=1; nonstopmode; input pplr7t

Please type another input file name
! Emergency stop.
<*> ...:=ljfour; mag:=1; nonstopmode; input pplr7t

Transcript written on mfput.log.
grep: pplr7t.log: 没有那个文件或目录
mktextfm: `mf-nowin -progname=mf \mode:=ljfour; mag:=1; nonstopmode; input pplr7t' failed to make pplr7t.tfm.
kpathsea: Appending font creation commands to missfont.log.

! Font OT1/ppl/m/n/10=pplr7t at 10.0pt not loadable: Metric (TFM) file not foun
d.

                   relax
l.377 \normalfont
                 \selectfont

解决方法：
yum -y install texlive-collection-fontsrecommended texlive-times