Funding for this research was provided by:
Koszalin University of Technology
Article History
Received: 21 May 2019
Accepted: 23 May 2019
First Online: 7 June 2019
Compliance with ethical standards
:
: The authors declare that they have no conflicts of interest.
: For this type of study, the statement is not applicable.
: For this type of study, the statement is not applicable.