i have a longtable at the end of my paper. the code is as follows
\documentclass[journal]{IEEEtran}
\usepackage{longtable}
\usepackage{lipsum}
%\usepackage{capt-of}
\makeatletter
\def\LT@makecaption#1#2#3{%
\LT@mcol\LT@cols c{\hbox to\z@{\hss\parbox[t]\LTcapwidth{%
\footnotesize\bgroup\par\centering\@IEEEtabletopskipstrut{\normalfont\footnotesize #2}\\{\normalfont\footnotesize\scshape #3}\par\addvspace{0.5\baselineskip}\egroup\endgraf%
\@IEEEtablecaptionsepspace}%
\hss}}}
\makeatother
\begin{document}
\lipsum[4-9]
\begin{table}[]
\centering
\caption{State Table for My Machine\label{design1}}
\begin{tabular}{cccc}
\hline
a&b&c&d\\
\hline
1&2&3&4\\
\hline
\end{tabular}
\end{table}
\onecolumn
\begin{longtable}{lccccccccccccccr}
\caption{State Table for My Machine}\label{design2}\\
\hline
\multicolumn{2}{c}{Initial State} & R & C & sel & loc & \multicolumn{6}{c}{mol} & cre & con & r\_c & Final State \\
& & & & & & 5 & 4 & 3 & 2 & 1 & 0 & & & & \\
\hline
\endfirsthead
\multicolumn{16}{l}{Table \ref{design} continued from previous page...}\\
\hline
\multicolumn{2}{c}{Initial State} & R & C & sel & loc & \multicolumn{6}{c}{mol} & cre & con & r\_c & Final State \\
& & & & & & 5 & 4 & 3 & 2 & 1 & 0 & & & & \\
\hline
\endhead
\hline
\endfoot
x & xxxx & x & x & x & xx & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & OOO \\ \hline
OOO & 0000 & 0 & 0 & x & x0 & 1 & 1 & 1 & 1 & & & 0 & 0 & 0 & PO \\
& 0000 & 0 & 0 & x & x1 & & & & & 1 & 1 & 0 & 0 & 0 & OOP \\
& 0000 & 0 & 1 & x & 00 & 1 & 0 & & & & & 0 & 1 & 0 & XOO \\
& 0000 & 0 & 1 & x & 01 & & & 1 & 0 & & & 0 & 1 & 0 & OXO \\
& 0000 & 0 & 1 & x & 10 & & & & & 1 & 0 & 0 & 1 & 0 & OOX \\
& 0000 & 1 & 0 & x & 00 & 0 & 1 & & & & & 0 & 1 & 1 & XOO \\
& 0000 & 1 & 0 & x & 01 & & & 0 & 1 & & & 0 & 1 & 1 & OXO \\
& 0000 & 1 & 0 & x & 10 & & & & & 0 & 1 & 0 & 1 & 1 & OOX \\
& 0000 & 1 & 1 & 0 & 00 & 0 & 1 & & & & & 0 & 1 & 1 & XOO \\
& 0000 & 1 & 1 & 0 & 01 & & & 0 & 1 & & & 0 & 1 & 1 & OXO \\
& 0000 & 1 & 1 & 0 & 10 & & & & & 0 & 1 & 0 & 1 & 1 & OOX \\
& 0000 & 1 & 1 & 1 & 00 & 1 & 0 & & & & & 0 & 1 & 0 & XOO \\
& 0000 & 1 & 1 & 1 & 01 & & & 1 & 0 & & & 0 & 1 & 0 & OXO \\
& 0000 & 1 & 1 & 1 & 10 & & & & & 1 & 0 & 0 & 1 & 0 & OOX \\
\end{longtable}
\twocolumn
\lipsum[5]
\end{document}
the longtable starts on a new page. i want it to start right under the two column text on the last page. how can this be done?

\onecolumn. this command always start new page. this have nothing with long table. – Zarko Jan 12 '18 at 07:21table*, first at bottom of page, second on the top of the next page. for this you will need to load packagestfloats. – Zarko Jan 12 '18 at 11:43