deletions | additions       diff --git a/section_Concept_of_Smart_Floor__.tex b/section_Concept_of_Smart_Floor__.tex  index a7f2e3e..d59e4c2 100644  --- a/section_Concept_of_Smart_Floor__.tex  +++ b/section_Concept_of_Smart_Floor__.tex 
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Indoor localization is one of the most challenging and important tasks of various systems, especially in the domain of assistive robotic systems, intelligent space and smart environments. Methods that utilize cameras and/or laser range finders require complex recognition algorithms, which can then in turn consume a lot of processing power. A smart floor alleviates this kind of problem.    There are several ways how to implement a smart floor. One way is to utilize pressure sensors. Examples of this approach are described e.g. in \cite{Mori_2004} and \cite{Orr_2000}, where pressure sensors were used to detect and track users in the testing environment.  Equiping an entire floor with pressure sensors can be time and resource consuming in and on itself as every tile needs to send its data to the system. So a question of data transfer must be extra solved. Additionally, solved additionally. Moreover,  as pointed out in \cite{Mori_2004} pressure sensors have troubles with tracking multiple people near each other and with differentiating between them. This problem can be solved by opting to use using the  RFID (Radio-frequency identification) technology instead. (Radio-Frequency IDentification) technology.  RFID relies on the wireless transfer of data using electromagnetic fields. RFID tags contain stored information information,  which can then be accessed with by  an appropriate reader (\ref{fig:fig2}). Some tags as shown in fig.~\ref{fig:fig2}. There  are two kinds of RFID tags -- \textit{passive} and \textit{active} ones. A passive tag is  powered by electromagneticinduction from magnetic fields produced near the reader. Some types collect energy from the interrogating radio  waves of the reader, whose antenna is induced  and act as a passive transponder. Other types have so it can send information to the reader. Its main limitation is in  a very short range of several tens of centimeters. An active tag has its own  local power source such as in the form of  a battery and hereby it  may operate at hundreds of meters from the reader. This approach was also Of course, active RFID tags are more expensive as passive ones and their bigger dimensions can cause other problems in some applications, too. Use of both types of RFID tags were  explored e.g.  in \cite{K_mpke_2008}, \cite{Johansson_2009}, \cite{Ku_2011} and \cite{khaliqstigmergic}.