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\hypersetup{pdftitle={Application of Fuzzy Logic"=based Modelling to Allocate Skidding Machines in Forest Operation},pdfauthor={Ismael Ghajar, Akbar Najafi, Najibeh Gilanipour},pdfsubject={Tropentag 2010: Abstract},pdfkeywords={Forest harvesting, Fuzzy rule-based modelling, log extraction, Resource allocation, Skidding cost, Time study},pdfpagemode=None,colorlinks=true}
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\parbox[b]{13.4cm}{\centering \large{\textbf{Tropentag, September 14-16, 2010, Zurich}}\\[1ex] \Large{``World Food System  ---\\A Contribution from Europe''\\[2ex]}}
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\Large{\textbf{Application of Fuzzy Logic"=based Modelling to Allocate Skidding Machines in Forest Operation\footnote{\textbf{Contact Address:} Ismael Ghajar, Tarbiat Modares University, Forestry, Imamreza, Noor, Iran, \mbox{e-mail}: \email{ismael.ghajar@modares.ac.ir}}\\[0.8ex]}}
\normalsize{\textsc{Ismael Ghajar$^{1}$, Akbar Najafi$^{2}$, Najibeh Gilanipour$^{3}$}}
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\begin{itemize*}
\item[]{\small{\textit{$^{1}$Tarbiat Modares University, Forestry, Iran}}}
\item[]{\small{\textit{$^{2}$Tarbiat Modares University, Forestry, Iran}}}
\item[]{\small{\textit{$^{3}$Tarbiat Modares University, Forestry, }}}
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\index[author]{Ghajar, Ismael}
\index[author]{Najafi, Akbar}
\index[author]{Gilanipour, Najibeh}
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\textbf{Abstract}
\begin{abstract}
\normalsize{
Forest planning and management is a complicated proposition in many mountainous regions where there are varieties of physiographic factors. With development of mechanisation, resource allocation and determining the efficiency of machines used in forest harvesting are essential.  The aim of this research is to provide a framework to determine the economical activity zone of forest operation machines so that this allocation would cause to highest net profit for forest managers. In traditional logic, inputs are supposed as unambiguously defined attributes and all inferences are based on clear threshold of class inputs, while most concepts in forest operations could not be defined precisely or have no clearly characterised boundaries in space and time. Analyze of such data entail a technology that applies both intuition (expert knowledge) and engineering heuristic to enhance model"=based system designs. Two fuzzy expert systems developed to handle uncertain variables and vague range of logs volume and physiographic conditions as inputs of fuzzy inference models for allocating two commonly used skidding machines (i.e. Timberjack 450c and farm tractor) in the north of Iran. Membership functions and fuzzy rule bases were created with contribution of experts' knowledge and existing machine productivity models. In fact Fuzzy rule"=based models reflect how to integrate expert knowledge with engineering system design. These models could serve as decision support systems during the tactical planning phase of forest management planning. To present an example, an investigation were performed using two developed models in approximately \mbox{7323\,ha} of mountainous forest, which inventory data were existed and harvesting should be done in next period.}

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\noindent \textbf{Keywords:} Forest harvesting, fuzzy rule"=based modelling, log extraction, resource allocation, skidding cost, time study
\index[key]{Forest!harvesting}
\index[key]{Fuzzy rule"=based modeling}
\index[key]{Log extraction}
\index[key]{Resource!allocation}
\index[key]{Skidding cost}
\index[key]{Time study}
\end{document}