182
P. Cardei et al.
3 Conclusions
From the scientific point of view, the presented results show that the methodology
followed is an efficient one: the measurement and the interpolation of the experimental results by classical and nonstandard distance functions. The accuracy of
calculation of theoretical models is appropriate and increases with the distance from
the source.
It is useful to consider the dependence of the logarithmic term in the expression of
the noise intensity level, by the more complicated terms than the distance, because the
reformulation of the logarithm function argument regulates its dimensional condition
and, furthermore, it can also highlight other parameters of the model. We believe
that this methodology can also contribute to efforts to eliminate singularities in
the acoustic wave propagation equations. However, it is proven that experimental
and theoretical-empirical research can achieve the satisfactory precision required in
practical applications, even considering slightly different terms in the propagation
equations, in relation to the theoretical solution.
The immediate application of experimental and theoretical research described in
the article is to increase the level of noise protection for human staff working on
the agricultural machines trailed by tractors. Even in the specific case of the tractor
under consideration, the noise field has values that fall within the hours of exposure
for 8–10 h of daily work, however, it is estimated that in a dynamic regime, the
noise can increase by 2–5 dB, thus, that its estimation enters somewhere in the
questionable area, which imposes the limitation of working time. The discussion
is more complicated if account is taken of the frequencies of noise propagation,
but especially if there are other sources of pollution: traction engine emissions,
vibrations, difficult jobs. These are arguments for a comprehensive multidisciplinary
study. In addition, as shown in [4], for example, tractors of older or used generations
can produce more intense noise levels.
Acknowledgements This work was supported by a grant of the Romanian Research and Innovation Ministry, through Programme 1—Development of the national research-development system,
subprogram 1.2—Institutional performance—Projects for financing excellence in RDI, contract
No. 16PFE.
References
1. P. Cardei, M. Ludig, M. Matache, R. Sfiru, Mathematical modeling and use in acoustics
applications in agriculture. Sci. J. Agric. Eng. 2, 81–89 (2014)
2. P. Cardei, Some proposal for the improvement of the simulations of the acoustic noise
propagation. Int. J. Math. Models Methods Appl. Sci. 285–293 (2008)
3. E. Sorica, V. Vladut, P. Cardei, C. Sorica, C. Bracacescu, Comparative analysis of the noise and
vibration transmitted to the operator by a brush cutter, in Acoustics and Vibration of Mechanical
Structures—AVMS-2017, (Springer, Cham 2018), pp. 165–172
P. Cardei et al.
3 Conclusions
From the scientific point of view, the presented results show that the methodology
followed is an efficient one: the measurement and the interpolation of the experimental results by classical and nonstandard distance functions. The accuracy of
calculation of theoretical models is appropriate and increases with the distance from
the source.
It is useful to consider the dependence of the logarithmic term in the expression of
the noise intensity level, by the more complicated terms than the distance, because the
reformulation of the logarithm function argument regulates its dimensional condition
and, furthermore, it can also highlight other parameters of the model. We believe
that this methodology can also contribute to efforts to eliminate singularities in
the acoustic wave propagation equations. However, it is proven that experimental
and theoretical-empirical research can achieve the satisfactory precision required in
practical applications, even considering slightly different terms in the propagation
equations, in relation to the theoretical solution.
The immediate application of experimental and theoretical research described in
the article is to increase the level of noise protection for human staff working on
the agricultural machines trailed by tractors. Even in the specific case of the tractor
under consideration, the noise field has values that fall within the hours of exposure
for 8–10 h of daily work, however, it is estimated that in a dynamic regime, the
noise can increase by 2–5 dB, thus, that its estimation enters somewhere in the
questionable area, which imposes the limitation of working time. The discussion
is more complicated if account is taken of the frequencies of noise propagation,
but especially if there are other sources of pollution: traction engine emissions,
vibrations, difficult jobs. These are arguments for a comprehensive multidisciplinary
study. In addition, as shown in [4], for example, tractors of older or used generations
can produce more intense noise levels.
Acknowledgements This work was supported by a grant of the Romanian Research and Innovation Ministry, through Programme 1—Development of the national research-development system,
subprogram 1.2—Institutional performance—Projects for financing excellence in RDI, contract
No. 16PFE.
References
1. P. Cardei, M. Ludig, M. Matache, R. Sfiru, Mathematical modeling and use in acoustics
applications in agriculture. Sci. J. Agric. Eng. 2, 81–89 (2014)
2. P. Cardei, Some proposal for the improvement of the simulations of the acoustic noise
propagation. Int. J. Math. Models Methods Appl. Sci. 285–293 (2008)
3. E. Sorica, V. Vladut, P. Cardei, C. Sorica, C. Bracacescu, Comparative analysis of the noise and
vibration transmitted to the operator by a brush cutter, in Acoustics and Vibration of Mechanical
Structures—AVMS-2017, (Springer, Cham 2018), pp. 165–172