# how to remove duplicated sections in the generated pdf using MikTex and how to use \keyword command

For the following .tex I got an error on \keyword tag and after commented it I got another problem at the generated pdf file which is a dublication for the abstract at the end of the document as in the following:

generated pdf

This the minimal .tex file:

\documentclass[preprint,12pt]{elsarticle}

\journal{}
\newtheorem{definition}{Definition}

\usepackage{graphicx}
\graphicspath{{./Figures/}}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{bm}
\usepackage{amsfonts}
\usepackage{filecontents}
\usepackage{natbib}
\usepackage{caption}
\usepackage{subcaption}

\providecommand{\keywords}[1]{\textbf{\textit{Index terms---}} #1}

\usepackage{epstopdf}
\epstopdfsetup{outdir=./}

\usepackage{colortbl}

\usepackage[ruled,vlined]{algorithm2e} \providecommand{\SetAlgoLined}{\SetLine}

\providecommand{\DontPrintSemicolon}{\dontprintsemicolon}
\begin{document}

\begin{frontmatter}

\title{}
\tnotetext[label1]{}

\author{......}

\author{.......}

\author{......}

\begin{abstract}

%\keywords{blablabla \and bla \and bla \and blablabla \and blablabla}

\end{abstract}

\maketitle

\section{Introduction}
\label{sec:intro}

\section{Background and Related Work}
\label{sec:back}

\subsection{Discussion}

\section{Conclusion}
\label{sec:conc}

% use section* for acknowledgment
\section*{Acknowledgment}

\end{frontmatter}

\end{document}


I got the following errors when I moved the comment:

! Misplaced \crcr.\endarray ->\crcr\egroup \egroup \gdef \@preamble {}\CT@end ...and graph-based computation \and big data}

• ... "I got an error on \keyword tag" ...: Please provide the contents of the error message. – Mico Mar 6 '16 at 6:01
• Are you sure that \end{frontmatter} has to go there? It should replace \maketitle, instead. – egreg Mar 6 '16 at 9:49
• @Mico I've updated my question, is there any solution for key word problem ?? – Student. Engineering Mar 6 '16 at 13:33

The \end{frontmatter} command must be where you have \maketitle; note that \maketitle isn't even mentioned in the manual of elsarticle.

\documentclass[preprint,12pt]{elsarticle}

\journal{Multimedia Tools and Applications}
\newtheorem{definition}{Definition}

\usepackage{graphicx}
\graphicspath{{./Figures/}}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{bm}
\usepackage{amsfonts}
\usepackage{filecontents}
\usepackage{natbib}
\usepackage{caption}
\usepackage{subcaption}

\providecommand{\keywords}[1]{\textbf{\textit{Index terms---}} #1}

\usepackage{epstopdf}
\epstopdfsetup{outdir=./}

\usepackage{colortbl}

\usepackage[ruled,vlined]{algorithm2e} \providecommand{\SetAlgoLined}{\SetLine}

\providecommand{\DontPrintSemicolon}{\dontprintsemicolon}
\begin{document}

\begin{frontmatter}

\title{MedGraph: A Graph-Based Representation and Computation to Handle Large Sets of Images\tnoteref{label1}}
\tnotetext[label1]{}

\author{......}

\author{.......}

\author{......}

\begin{abstract}

In order to process and analyze very large volumes of images, efficient representation and structuring techniques are required. Since, current computing machines can provide large memory size, trading off reasonable amount of memory in order to achieve efficient and parallelizable representation of images is preferable. In this paper, we propose a new structure to represent and store images based on in-memory graph concept.

%\keywords{Image processing \and region of interest (ROI) \and medical images \and graph-based computation \and big data}

\end{abstract}

\end{frontmatter}

\section{Introduction}
\label{sec:intro}

\section{Background and Related Work}
\label{sec:back}

\subsection{Big data and graph-based systems}

\subsection{Image representation}

\subsection{Discussion}

Although MedGraph provides novelty in image representations as grid graphs, there are some limitations for image processing algorithms that apply a divide-and-conquer approach or benefit from spatial locality. To see this, consider the following examples. The first example is when there is a need to jump directly to a pixel in the middle of an image as it might be the case with divide-and-conquer algorithms.

\section{Conclusion}
\label{sec:conc}
The volume of medical images grows rapidly and new techniques are needed to achieve efficient management and manipulation.

% use section* for acknowledgment
\section*{Acknowledgment}

\end{document}