\documentclass[a4paper,11pt]{article}
\topmargin=-2cm
\evensidemargin=.5cm
\oddsidemargin=.5cm
\textwidth=15cm
\textheight=23cm
\newcommand{\tipo}[1]{\noindent{\footnotesize #1} \medskip}
\thispagestyle{empty}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\tipo{\it{SMART\ 2014 \hspace{6cm} Pontignano, Italy, September 28--October 1, 2014}}\\
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Title: capitalize the initial letter of each significant word of the title%%%
\vskip .1cm
\centerline {\LARGE {\bf Title }}
%\vskip .1cm
%\centerline {\Large {\bf Title line 2}}
%\vskip .1cm
%\centerline {\Large {\bf Title line 3}}
%%%%%%%%%%%%%%%%%%%%
\vskip .5cm
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Insert name and surname of each author.  The speaker's name and surname should be underlined.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \centerline {\Large  Author 1, \underline{Author 2}, .....}
\vskip .5cm
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\vskip 1cm  \noindent  {\Large {\bf Abstract}} \vskip .2cm

\noindent The abstract should be maximum 1 page. %\cite{Boor,Castel,Farin}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% Bibliography format, if needed.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%\begin{thebibliography}{10} \small\itemsep-1pt

%\bibitem{Boor}
%C. de Boor (2001), {\it A practical guide to splines.} Revised edition. Springer-Verlag, New York.
 
%\bibitem{Castel}
%P. de Casteljau (1995), Esthetic curves and profiles versus orthogonal functions (a real experience), 
%{\it Mathematical methods for curves and surfaces} (Ulvik, 1994), 73--82, 
%Vanderbilt Univ. Press, Nashville, TN.

%\bibitem{Farin}
%G. Farin (1993), Tighter convex hulls for rational Bézier curves. {\it Comput. Aided Geom. Design} 10,  123--125.
%\end{thebibliography}

\bigskip
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{flushleft} 
Author 1, affiliation 1. \medskip \\ 
Author 2, affiliation 2.
%\medskip \\ 
% Author 3, affiliaton
\end{flushleft}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \end{document}