TY  - CONF
AU  - Davidović, Miloš
AU  - Kleut, Duška
AU  - Davidović, Milena D.
AU  - Stojanović, Danka B.
AU  - Jovašević-Stojanović, Milena
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13046
AB  - Atmospheric aerosols in urban areas typically consist of particles of different diameters, which can range in size from a few nanometers to a few micrometers and can have a strong impact on human health [1,2]. This motivates the need to measure aerosol concentration accurately, but it is often also necessary to combine results from several instruments, with fundamentally different measurement principles. In this work, methods based on the measurement of the electrical mobility of particles, for the range of diameters from 10nm to 420nm, and the measurement of the equivalent optical diameter, for the range of diameters from 300nm to 10um, were used. Combining the overlapping region in two size distribution spectra can be used to infer equivalent optical properties of the ambient aerosol, and examples of measured and combined spectra in several urban hot spots in Bay of Kotor are analyzed in some detail. These examples will illustrate several aspects of urban aerosol properties not readily available in a typical regulatory monitoring setting, such as distribution of modes in number and mass concentration, as well as optical properties of measured aerosol.  As the main result, examples of combining particle size spectrums are presented. In the process of combining the particle size spectra, it is possible to modify the distribution obtained by optical measurements by searching for the optimal value of the refractive index of the particles to obtain the best possible agreement with the size distribution obtained by measuring the electrical mobility. An equivalent refractive index as well as the equivalent shape factor of the ambient aerosol is obtained using Mie scattering theory as a theoretical framework [3]. The measurement results from the mobile monitoring campaign in Bay of Kotor in 2017 were used to elucidate the main principles of size spectrum combination, as well as to showcase diversity of equivalent optical properties of urban aerosols.
PB  - Belgrade : Institute of Physics
C3  - 16th Photonics Workshop : Book of abstracts
T1  - Combining size distribution spectrums of ambient aerosols using equivalent optical properties of nanosized particles – selected examples from the Bay of Kotor
SP  - 26
EP  - 26
UR  - https://hdl.handle.net/21.15107/rcub_vinar_13046
ER  - 

@conference{
author = "Davidović, Miloš and Kleut, Duška and Davidović, Milena D. and Stojanović, Danka B. and Jovašević-Stojanović, Milena",
year = "2023",
abstract = "Atmospheric aerosols in urban areas typically consist of particles of different diameters, which can range in size from a few nanometers to a few micrometers and can have a strong impact on human health [1,2]. This motivates the need to measure aerosol concentration accurately, but it is often also necessary to combine results from several instruments, with fundamentally different measurement principles. In this work, methods based on the measurement of the electrical mobility of particles, for the range of diameters from 10nm to 420nm, and the measurement of the equivalent optical diameter, for the range of diameters from 300nm to 10um, were used. Combining the overlapping region in two size distribution spectra can be used to infer equivalent optical properties of the ambient aerosol, and examples of measured and combined spectra in several urban hot spots in Bay of Kotor are analyzed in some detail. These examples will illustrate several aspects of urban aerosol properties not readily available in a typical regulatory monitoring setting, such as distribution of modes in number and mass concentration, as well as optical properties of measured aerosol.  As the main result, examples of combining particle size spectrums are presented. In the process of combining the particle size spectra, it is possible to modify the distribution obtained by optical measurements by searching for the optimal value of the refractive index of the particles to obtain the best possible agreement with the size distribution obtained by measuring the electrical mobility. An equivalent refractive index as well as the equivalent shape factor of the ambient aerosol is obtained using Mie scattering theory as a theoretical framework [3]. The measurement results from the mobile monitoring campaign in Bay of Kotor in 2017 were used to elucidate the main principles of size spectrum combination, as well as to showcase diversity of equivalent optical properties of urban aerosols.",
publisher = "Belgrade : Institute of Physics",
journal = "16th Photonics Workshop : Book of abstracts",
title = "Combining size distribution spectrums of ambient aerosols using equivalent optical properties of nanosized particles – selected examples from the Bay of Kotor",
pages = "26-26",
url = "https://hdl.handle.net/21.15107/rcub_vinar_13046"
}

Davidović, M., Kleut, D., Davidović, M. D., Stojanović, D. B.,& Jovašević-Stojanović, M.. (2023). Combining size distribution spectrums of ambient aerosols using equivalent optical properties of nanosized particles – selected examples from the Bay of Kotor. in 16th Photonics Workshop : Book of abstracts
Belgrade : Institute of Physics., 26-26.
https://hdl.handle.net/21.15107/rcub_vinar_13046

Davidović M, Kleut D, Davidović MD, Stojanović DB, Jovašević-Stojanović M. Combining size distribution spectrums of ambient aerosols using equivalent optical properties of nanosized particles – selected examples from the Bay of Kotor. in 16th Photonics Workshop : Book of abstracts. 2023;:26-26.
https://hdl.handle.net/21.15107/rcub_vinar_13046 .

Davidović, Miloš, Kleut, Duška, Davidović, Milena D., Stojanović, Danka B., Jovašević-Stojanović, Milena, "Combining size distribution spectrums of ambient aerosols using equivalent optical properties of nanosized particles – selected examples from the Bay of Kotor" in 16th Photonics Workshop : Book of abstracts (2023):26-26,
https://hdl.handle.net/21.15107/rcub_vinar_13046 .

TY  - CONF
AU  - Stojanović, Danka B.
AU  - Kleut, Duška
AU  - Davidović, Miloš
AU  - Lepioufle, Jean-Marie
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13047
AB  - Particulate matter (PM) in air has been proven to be hazardous to human health. Until recently, monitoring of air quality has been done by professional agencies. Nowadays, the availability of portable, low cost microsensor devices and the exponential growth of IoT (Internet of Things) in everyday life has enabled widespread monitoring of air quality among all citizens.[1]. For PM measurements, optical sensors measure light scattering by particles carried in an air stream through a light beam, which is converted by computation to equivalent mass concentration. Light scattering is strongly affected by parameters such as particle density, particle hygroscopicity, refraction index, and particle composition [2]. In this study, we measured PM 2.5 by seven AQ MESH low-cost optical sensors and compared the measured data with the ones obtained from the reference monitoring station (SEPA). Could we, by a sequence of low-processing data enrichment and a simple calibration method, reach an accuracy as close as a calibration based on machine learning? To answer this question, we used low-processing data enrichment such as resampling, encoding periodic timerelated features and making a composition of the initial low-cost signal at different time scales. We compared two algorithms for the calibration: multivariate linear regression and random forest. The results gave promising results and encouraged us in researching further about signal low-processing to achieve the required quality of data from low-cost sensor devices monitoring air quality [3].
PB  - Belgrade : Institute of Physics
C3  - 16th Photonics Workshop : Book of abstracts
T1  - Data enrichment and calibration for PM 2.5 low-cost optical sensors
SP  - 40
EP  - 40
UR  - https://hdl.handle.net/21.15107/rcub_vinar_13047
ER  - 

@conference{
author = "Stojanović, Danka B. and Kleut, Duška and Davidović, Miloš and Lepioufle, Jean-Marie",
year = "2023",
abstract = "Particulate matter (PM) in air has been proven to be hazardous to human health. Until recently, monitoring of air quality has been done by professional agencies. Nowadays, the availability of portable, low cost microsensor devices and the exponential growth of IoT (Internet of Things) in everyday life has enabled widespread monitoring of air quality among all citizens.[1]. For PM measurements, optical sensors measure light scattering by particles carried in an air stream through a light beam, which is converted by computation to equivalent mass concentration. Light scattering is strongly affected by parameters such as particle density, particle hygroscopicity, refraction index, and particle composition [2]. In this study, we measured PM 2.5 by seven AQ MESH low-cost optical sensors and compared the measured data with the ones obtained from the reference monitoring station (SEPA). Could we, by a sequence of low-processing data enrichment and a simple calibration method, reach an accuracy as close as a calibration based on machine learning? To answer this question, we used low-processing data enrichment such as resampling, encoding periodic timerelated features and making a composition of the initial low-cost signal at different time scales. We compared two algorithms for the calibration: multivariate linear regression and random forest. The results gave promising results and encouraged us in researching further about signal low-processing to achieve the required quality of data from low-cost sensor devices monitoring air quality [3].",
publisher = "Belgrade : Institute of Physics",
journal = "16th Photonics Workshop : Book of abstracts",
title = "Data enrichment and calibration for PM 2.5 low-cost optical sensors",
pages = "40-40",
url = "https://hdl.handle.net/21.15107/rcub_vinar_13047"
}

Stojanović, D. B., Kleut, D., Davidović, M.,& Lepioufle, J.. (2023). Data enrichment and calibration for PM 2.5 low-cost optical sensors. in 16th Photonics Workshop : Book of abstracts
Belgrade : Institute of Physics., 40-40.
https://hdl.handle.net/21.15107/rcub_vinar_13047

Stojanović DB, Kleut D, Davidović M, Lepioufle J. Data enrichment and calibration for PM 2.5 low-cost optical sensors. in 16th Photonics Workshop : Book of abstracts. 2023;:40-40.
https://hdl.handle.net/21.15107/rcub_vinar_13047 .

Stojanović, Danka B., Kleut, Duška, Davidović, Miloš, Lepioufle, Jean-Marie, "Data enrichment and calibration for PM 2.5 low-cost optical sensors" in 16th Photonics Workshop : Book of abstracts (2023):40-40,
https://hdl.handle.net/21.15107/rcub_vinar_13047 .