TY  - JOUR
AU  - Stratimirović, Đorđe
AU  - Sarvan, Darko
AU  - Miljković, Vladimir
AU  - Blesić, Suzana
PY  - 2018
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2329
AB  - In this paper we have analyzed scaling properties and cyclical behavior of the three types of stock market indexes (SMI) time series: data belonging to stock markets of developed economies, emerging economies, and of the underdeveloped or transitional economies. We have used two techniques of data analysis to obtain and verify our findings: the wavelet transform (WT) spectral analysis to identify cycles in the SMI returns data, and the time- dependent detrended moving average (tdDMA) analysis to investigate local behavior around market cycles and trends. We found cyclical behavior in all SMI data sets that we have analyzed. Moreover, the positions and the boundaries of cyclical intervals that we found seam to be common for all markets in our dataset. We list and illustrate the presence of nine such periods in our SMI data. We report on the possibilities to differ-entiate between the level of growth of the analyzed markets by way of statistical analysis of the properties of wavelet spectra that characterize particular peak behaviors. Our results show that measures like the relative WT energy content and the relative WT amplitude of the peaks in the small scales region could be used to partially differentiate between market economies. Finally, we propose a way to quantify the level of development of a stock market based on estimation of local complexity of market's SMI series. From the local scaling exponents calculated for our nine peak regions we have defined what we named the Development Index, which proved, at least in the case of our dataset, to be suitable to rank the SMI series that we have analyzed in three distinct groups.
PB  - Elsevier Science Bv, Amsterdam
T2  - Communications in Nonlinear Science & Numerical Simulation
T1  - Analysis of cyclical behavior in time series of stock market returns
VL  - 54
SP  - 21
EP  - 33
DO  - 10.1016/j.cnsns.2017.05.009
ER  - 

@article{
author = "Stratimirović, Đorđe and Sarvan, Darko and Miljković, Vladimir and Blesić, Suzana",
year = "2018",
abstract = "In this paper we have analyzed scaling properties and cyclical behavior of the three types of stock market indexes (SMI) time series: data belonging to stock markets of developed economies, emerging economies, and of the underdeveloped or transitional economies. We have used two techniques of data analysis to obtain and verify our findings: the wavelet transform (WT) spectral analysis to identify cycles in the SMI returns data, and the time- dependent detrended moving average (tdDMA) analysis to investigate local behavior around market cycles and trends. We found cyclical behavior in all SMI data sets that we have analyzed. Moreover, the positions and the boundaries of cyclical intervals that we found seam to be common for all markets in our dataset. We list and illustrate the presence of nine such periods in our SMI data. We report on the possibilities to differ-entiate between the level of growth of the analyzed markets by way of statistical analysis of the properties of wavelet spectra that characterize particular peak behaviors. Our results show that measures like the relative WT energy content and the relative WT amplitude of the peaks in the small scales region could be used to partially differentiate between market economies. Finally, we propose a way to quantify the level of development of a stock market based on estimation of local complexity of market's SMI series. From the local scaling exponents calculated for our nine peak regions we have defined what we named the Development Index, which proved, at least in the case of our dataset, to be suitable to rank the SMI series that we have analyzed in three distinct groups.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Communications in Nonlinear Science & Numerical Simulation",
title = "Analysis of cyclical behavior in time series of stock market returns",
volume = "54",
pages = "21-33",
doi = "10.1016/j.cnsns.2017.05.009"
}

Stratimirović, Đ., Sarvan, D., Miljković, V.,& Blesić, S.. (2018). Analysis of cyclical behavior in time series of stock market returns. in Communications in Nonlinear Science & Numerical Simulation
Elsevier Science Bv, Amsterdam., 54, 21-33.
https://doi.org/10.1016/j.cnsns.2017.05.009

Stratimirović Đ, Sarvan D, Miljković V, Blesić S. Analysis of cyclical behavior in time series of stock market returns. in Communications in Nonlinear Science & Numerical Simulation. 2018;54:21-33.
doi:10.1016/j.cnsns.2017.05.009 .

Stratimirović, Đorđe, Sarvan, Darko, Miljković, Vladimir, Blesić, Suzana, "Analysis of cyclical behavior in time series of stock market returns" in Communications in Nonlinear Science & Numerical Simulation, 54 (2018):21-33,
https://doi.org/10.1016/j.cnsns.2017.05.009 . .

TY  - JOUR
AU  - Sarvan, Darko
AU  - Stratimirović, Đorđe
AU  - Blesić, Suzana
AU  - Đurđević, Vladimir
AU  - Miljković, Vladimir
AU  - Ajtić, Jelena
PY  - 2017
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2198
AB  - The dynamics of the beryllium-7 specific activity in surface air over 1987-2011 is analyzed using wavelet transform (WT) analysis and time -dependent detrended moving average (tdDMA) method, WT analysis gives four periodicities in the beryllium-7 specific activity: one month, three months, one year, and three years. These intervals are further used in tdDMA to calculate local autocorrelation exponents for precipitation, tropopause height and teleconnection indices. Our results show that these parameters share common periods with the beryllium-7 surface concentration. tdDMA method indicates that on the characteristic intervals of one year and shorter, the beryllium-7 specific activity is strongly autocorrelated. On the three-year interval, the beryllium-7 specific activity shows periods of anticorrelat ion, implying slow changes in its dynamics that become evident only over a prolonged period of time. A comparison of the Hurst exponents of all the variables on the one- and three-year intervals suggest some similarities in their dynamics. Overall, a good agreement in the behavior of the teleconnection indices and specific activity of beryllium-7 in surface air is noted.
PB  - Elsevier, Amsterdam
T2  - Physica A-Statistical Mechanics & its Applications
T1  - Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number
VL  - 469
SP  - 813
EP  - 823
DO  - 10.1016/j.physa.2016.11.040
ER  - 

@article{
author = "Sarvan, Darko and Stratimirović, Đorđe and Blesić, Suzana and Đurđević, Vladimir and Miljković, Vladimir and Ajtić, Jelena",
year = "2017",
abstract = "The dynamics of the beryllium-7 specific activity in surface air over 1987-2011 is analyzed using wavelet transform (WT) analysis and time -dependent detrended moving average (tdDMA) method, WT analysis gives four periodicities in the beryllium-7 specific activity: one month, three months, one year, and three years. These intervals are further used in tdDMA to calculate local autocorrelation exponents for precipitation, tropopause height and teleconnection indices. Our results show that these parameters share common periods with the beryllium-7 surface concentration. tdDMA method indicates that on the characteristic intervals of one year and shorter, the beryllium-7 specific activity is strongly autocorrelated. On the three-year interval, the beryllium-7 specific activity shows periods of anticorrelat ion, implying slow changes in its dynamics that become evident only over a prolonged period of time. A comparison of the Hurst exponents of all the variables on the one- and three-year intervals suggest some similarities in their dynamics. Overall, a good agreement in the behavior of the teleconnection indices and specific activity of beryllium-7 in surface air is noted.",
publisher = "Elsevier, Amsterdam",
journal = "Physica A-Statistical Mechanics & its Applications",
title = "Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number",
volume = "469",
pages = "813-823",
doi = "10.1016/j.physa.2016.11.040"
}

Sarvan, D., Stratimirović, Đ., Blesić, S., Đurđević, V., Miljković, V.,& Ajtić, J.. (2017). Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number. in Physica A-Statistical Mechanics & its Applications
Elsevier, Amsterdam., 469, 813-823.
https://doi.org/10.1016/j.physa.2016.11.040

Sarvan D, Stratimirović Đ, Blesić S, Đurđević V, Miljković V, Ajtić J. Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number. in Physica A-Statistical Mechanics & its Applications. 2017;469:813-823.
doi:10.1016/j.physa.2016.11.040 .

Sarvan, Darko, Stratimirović, Đorđe, Blesić, Suzana, Đurđević, Vladimir, Miljković, Vladimir, Ajtić, Jelena, "Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number" in Physica A-Statistical Mechanics & its Applications, 469 (2017):813-823,
https://doi.org/10.1016/j.physa.2016.11.040 . .

TY  - JOUR
AU  - Blesić, Suzana
AU  - Stratimirović, Đorđe
AU  - Ajtić, Jelena
AU  - Wright, Caradee Y.
AU  - Allen, Martin W.
PY  - 2016
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2098
AB  - Personal sun exposure measurements provide important information to guide the development of sun awareness and disease prevention campaigns. We assess the scaling properties of personal ultraviolet radiation (pUVR) sun exposure measurements using the wavelet transform (WT) spectral analysis to process long-range, high-frequency personal recordings collected by electronic UVR dosimeters designed to measure erythemal UVR exposure. We analysed the sun exposure recordings of school children, farmers, marathon runners and outdoor workers in South Africa, and construction workers and work site supervisors in New Zealand. We found scaling behaviour in all the analysed pUVR data sets. We found that the observed scaling changes from uncorrelated to long-range correlated with increasing duration of sun exposure. Peaks in the WT spectra that we found suggest the existence of characteristic times in sun exposure behaviour that were to some extent universal across our data set. Our study also showed that WT measures enable group classification, as well as distinction between individual UVR exposures, otherwise unattainable by conventional statistical methods.
PB  - Nature Publishing Group, New York
T2  - Journal of Exposure Science & Environmental Epidemiology
T1  - Novel approach to analysing large data sets of personal sun exposure measurements
VL  - 26
IS  - 6
SP  - 613
EP  - 620
DO  - 10.1038/jes.2016.43
ER  - 

@article{
author = "Blesić, Suzana and Stratimirović, Đorđe and Ajtić, Jelena and Wright, Caradee Y. and Allen, Martin W.",
year = "2016",
abstract = "Personal sun exposure measurements provide important information to guide the development of sun awareness and disease prevention campaigns. We assess the scaling properties of personal ultraviolet radiation (pUVR) sun exposure measurements using the wavelet transform (WT) spectral analysis to process long-range, high-frequency personal recordings collected by electronic UVR dosimeters designed to measure erythemal UVR exposure. We analysed the sun exposure recordings of school children, farmers, marathon runners and outdoor workers in South Africa, and construction workers and work site supervisors in New Zealand. We found scaling behaviour in all the analysed pUVR data sets. We found that the observed scaling changes from uncorrelated to long-range correlated with increasing duration of sun exposure. Peaks in the WT spectra that we found suggest the existence of characteristic times in sun exposure behaviour that were to some extent universal across our data set. Our study also showed that WT measures enable group classification, as well as distinction between individual UVR exposures, otherwise unattainable by conventional statistical methods.",
publisher = "Nature Publishing Group, New York",
journal = "Journal of Exposure Science & Environmental Epidemiology",
title = "Novel approach to analysing large data sets of personal sun exposure measurements",
volume = "26",
number = "6",
pages = "613-620",
doi = "10.1038/jes.2016.43"
}

Blesić, S., Stratimirović, Đ., Ajtić, J., Wright, C. Y.,& Allen, M. W.. (2016). Novel approach to analysing large data sets of personal sun exposure measurements. in Journal of Exposure Science & Environmental Epidemiology
Nature Publishing Group, New York., 26(6), 613-620.
https://doi.org/10.1038/jes.2016.43

Blesić S, Stratimirović Đ, Ajtić J, Wright CY, Allen MW. Novel approach to analysing large data sets of personal sun exposure measurements. in Journal of Exposure Science & Environmental Epidemiology. 2016;26(6):613-620.
doi:10.1038/jes.2016.43 .

Blesić, Suzana, Stratimirović, Đorđe, Ajtić, Jelena, Wright, Caradee Y., Allen, Martin W., "Novel approach to analysing large data sets of personal sun exposure measurements" in Journal of Exposure Science & Environmental Epidemiology, 26, no. 6 (2016):613-620,
https://doi.org/10.1038/jes.2016.43 . .

TY  - CONF
AU  - Stratimirović, Đorđe
AU  - Blesić, Suzana
AU  - Wright, Caradee Y.
AU  - Allen, Martin W.
AU  - Ajtić, Jelena
PY  - 2015
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2057
AB  - Scaling properties of personal solar ultraviolet radiation exposure (pUVR) recordings are investigated using the Wavelet Transform (WT) spectral analysis. Personal UVR recordings are collected by UVR monitors designed to measure erythemal UVR. Sun exposure recordings of a school child, farmer, marathon runner and outdoor worker in South Africa are analyzed. A scaling behavior in all analyzed pUVR datasets is found. The scaling behavior changes from uncorrelated to long-range correlated as duration of a person's solar exposure increases. The slopes of calculated WT power vary from 0, in the uncorrelated case for persons with erratic activities in reference to their UVR exposure, to close to 1 in the case of long-range correlated pUVR data, for persons spending longer periods in the sun. Peaks in the WT power spectra are also found, pointing to the existence of characteristic times in sun exposure behavior. Characteristic peaks at approximately 15 minutes, half an hour and an hour are present in all pUVR data, while persons with longer sun exposure have additional peaks at longer periods.
PB  - RAD Association
C3  - RAD Conference Proceedings
T1  - Wavelet analysis of personal solar UVR exposure
VL  - 2015-June
SP  - 443
EP  - 446
UR  - https://hdl.handle.net/21.15107/rcub_veterinar_1253
ER  - 

@conference{
author = "Stratimirović, Đorđe and Blesić, Suzana and Wright, Caradee Y. and Allen, Martin W. and Ajtić, Jelena",
year = "2015",
abstract = "Scaling properties of personal solar ultraviolet radiation exposure (pUVR) recordings are investigated using the Wavelet Transform (WT) spectral analysis. Personal UVR recordings are collected by UVR monitors designed to measure erythemal UVR. Sun exposure recordings of a school child, farmer, marathon runner and outdoor worker in South Africa are analyzed. A scaling behavior in all analyzed pUVR datasets is found. The scaling behavior changes from uncorrelated to long-range correlated as duration of a person's solar exposure increases. The slopes of calculated WT power vary from 0, in the uncorrelated case for persons with erratic activities in reference to their UVR exposure, to close to 1 in the case of long-range correlated pUVR data, for persons spending longer periods in the sun. Peaks in the WT power spectra are also found, pointing to the existence of characteristic times in sun exposure behavior. Characteristic peaks at approximately 15 minutes, half an hour and an hour are present in all pUVR data, while persons with longer sun exposure have additional peaks at longer periods.",
publisher = "RAD Association",
journal = "RAD Conference Proceedings",
title = "Wavelet analysis of personal solar UVR exposure",
volume = "2015-June",
pages = "443-446",
url = "https://hdl.handle.net/21.15107/rcub_veterinar_1253"
}

Stratimirović, Đ., Blesić, S., Wright, C. Y., Allen, M. W.,& Ajtić, J.. (2015). Wavelet analysis of personal solar UVR exposure. in RAD Conference Proceedings
RAD Association., 2015-June, 443-446.
https://hdl.handle.net/21.15107/rcub_veterinar_1253

Stratimirović Đ, Blesić S, Wright CY, Allen MW, Ajtić J. Wavelet analysis of personal solar UVR exposure. in RAD Conference Proceedings. 2015;2015-June:443-446.
https://hdl.handle.net/21.15107/rcub_veterinar_1253 .

Stratimirović, Đorđe, Blesić, Suzana, Wright, Caradee Y., Allen, Martin W., Ajtić, Jelena, "Wavelet analysis of personal solar UVR exposure" in RAD Conference Proceedings, 2015-June (2015):443-446,
https://hdl.handle.net/21.15107/rcub_veterinar_1253 .

TY  - JOUR
AU  - Sarvan, Darko
AU  - Stratimirović, Đorđe
AU  - Blesić, Suzana
AU  - Miljković, Vladimir
PY  - 2014
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1890
AB  - In this paper we have analyzed scaling properties of time series of stock market indices (SMIs) of developing economies of Western Balkans, and have compared the results we have obtained with the results from more developed economies. We have used three different techniques of data analysis to obtain and verify our findings: detrended fluctuation analysis (DFA) method, detrended moving average (DMA) method, and wavelet transformation (WT) analysis. We have found scaling behavior in all SMI data sets that we have analyzed. The scaling of our SMI series changes from long-range correlated to slightly anti-correlated behavior with the change in growth or maturity of the economy the stock market is embedded in. We also report the presence of effects of potential periodic-like influences on the SMI data that we have analyzed. One such influence is visible in all our SMI series, and appears at a period T-p approximate to 90 days. We propose that the existence of various periodic-like influences on SMI data may partially explain the observed difference in types of correlated behavior of corresponding scaling functions.
PB  - Springer, New York
T2  - European Physical Journal B
T1  - Scaling analysis of time series of daily prices from stock markets of transitional economies in the Western Balkans
VL  - 87
IS  - 12
DO  - 10.1140/epjb/e2014-50655-5
ER  - 

@article{
author = "Sarvan, Darko and Stratimirović, Đorđe and Blesić, Suzana and Miljković, Vladimir",
year = "2014",
abstract = "In this paper we have analyzed scaling properties of time series of stock market indices (SMIs) of developing economies of Western Balkans, and have compared the results we have obtained with the results from more developed economies. We have used three different techniques of data analysis to obtain and verify our findings: detrended fluctuation analysis (DFA) method, detrended moving average (DMA) method, and wavelet transformation (WT) analysis. We have found scaling behavior in all SMI data sets that we have analyzed. The scaling of our SMI series changes from long-range correlated to slightly anti-correlated behavior with the change in growth or maturity of the economy the stock market is embedded in. We also report the presence of effects of potential periodic-like influences on the SMI data that we have analyzed. One such influence is visible in all our SMI series, and appears at a period T-p approximate to 90 days. We propose that the existence of various periodic-like influences on SMI data may partially explain the observed difference in types of correlated behavior of corresponding scaling functions.",
publisher = "Springer, New York",
journal = "European Physical Journal B",
title = "Scaling analysis of time series of daily prices from stock markets of transitional economies in the Western Balkans",
volume = "87",
number = "12",
doi = "10.1140/epjb/e2014-50655-5"
}

Sarvan, D., Stratimirović, Đ., Blesić, S.,& Miljković, V.. (2014). Scaling analysis of time series of daily prices from stock markets of transitional economies in the Western Balkans. in European Physical Journal B
Springer, New York., 87(12).
https://doi.org/10.1140/epjb/e2014-50655-5

Sarvan D, Stratimirović Đ, Blesić S, Miljković V. Scaling analysis of time series of daily prices from stock markets of transitional economies in the Western Balkans. in European Physical Journal B. 2014;87(12).
doi:10.1140/epjb/e2014-50655-5 .

Sarvan, Darko, Stratimirović, Đorđe, Blesić, Suzana, Miljković, Vladimir, "Scaling analysis of time series of daily prices from stock markets of transitional economies in the Western Balkans" in European Physical Journal B, 87, no. 12 (2014),
https://doi.org/10.1140/epjb/e2014-50655-5 . .

TY  - JOUR
AU  - Blesić, Suzana
AU  - Stratimirović, Đorđe
AU  - Milošević, S.
AU  - Marić, J.
AU  - Kostić, V.
AU  - Ljubisavljević, M.
PY  - 2011
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1622
AB  - In this paper we have used the Wavelet Transform (WT) and the Detrended Fluctuation Analysis (DFA) methods to analyze hand tremor movements in essential tremor (ET), in two different recording conditions (before and after the addition of wrist-cuff load). We have analyzed the time series comprised of peak-to-peak (PtP) intervals, extracted from regions around the first three main frequency components of the power spectra (PwS) of the recorded tremors, in order to substantiate results related to the effects of load on ET, to distinguish between multiple sources of ET, and to separate the influence of peripheral factors on ET. Our results show that, in ET, the dynamical characteristics, that is, values of respective scaling exponents, of the main frequency component of recorded tremors change after the addition of load. Our results also show that in all the observed cases the scaling behavior of the calculated functions changes as well the calculated WT scalegrams and DFA functions display a shift in the position of the crossover when the load is added. We conclude that the difference in behavior of the WT and DFA functions between different conditions in ET could be associated with the expected pathology in ET, or with some additional mechanism that controls movements in ET patients, and causes the observed changes in scaling behavior.
PB  - Elsevier, Amsterdam
T2  - Physica A-Statistical Mechanics & its Applications
T1  - Scaling analysis of the effects of load on hand tremor movements in essential tremor
VL  - 390
IS  - 10
SP  - 1741
EP  - 1746
DO  - 10.1016/j.physa.2010.12.037
ER  - 

@article{
author = "Blesić, Suzana and Stratimirović, Đorđe and Milošević, S. and Marić, J. and Kostić, V. and Ljubisavljević, M.",
year = "2011",
abstract = "In this paper we have used the Wavelet Transform (WT) and the Detrended Fluctuation Analysis (DFA) methods to analyze hand tremor movements in essential tremor (ET), in two different recording conditions (before and after the addition of wrist-cuff load). We have analyzed the time series comprised of peak-to-peak (PtP) intervals, extracted from regions around the first three main frequency components of the power spectra (PwS) of the recorded tremors, in order to substantiate results related to the effects of load on ET, to distinguish between multiple sources of ET, and to separate the influence of peripheral factors on ET. Our results show that, in ET, the dynamical characteristics, that is, values of respective scaling exponents, of the main frequency component of recorded tremors change after the addition of load. Our results also show that in all the observed cases the scaling behavior of the calculated functions changes as well the calculated WT scalegrams and DFA functions display a shift in the position of the crossover when the load is added. We conclude that the difference in behavior of the WT and DFA functions between different conditions in ET could be associated with the expected pathology in ET, or with some additional mechanism that controls movements in ET patients, and causes the observed changes in scaling behavior.",
publisher = "Elsevier, Amsterdam",
journal = "Physica A-Statistical Mechanics & its Applications",
title = "Scaling analysis of the effects of load on hand tremor movements in essential tremor",
volume = "390",
number = "10",
pages = "1741-1746",
doi = "10.1016/j.physa.2010.12.037"
}

Blesić, S., Stratimirović, Đ., Milošević, S., Marić, J., Kostić, V.,& Ljubisavljević, M.. (2011). Scaling analysis of the effects of load on hand tremor movements in essential tremor. in Physica A-Statistical Mechanics & its Applications
Elsevier, Amsterdam., 390(10), 1741-1746.
https://doi.org/10.1016/j.physa.2010.12.037

Blesić S, Stratimirović Đ, Milošević S, Marić J, Kostić V, Ljubisavljević M. Scaling analysis of the effects of load on hand tremor movements in essential tremor. in Physica A-Statistical Mechanics & its Applications. 2011;390(10):1741-1746.
doi:10.1016/j.physa.2010.12.037 .

Blesić, Suzana, Stratimirović, Đorđe, Milošević, S., Marić, J., Kostić, V., Ljubisavljević, M., "Scaling analysis of the effects of load on hand tremor movements in essential tremor" in Physica A-Statistical Mechanics & its Applications, 390, no. 10 (2011):1741-1746,
https://doi.org/10.1016/j.physa.2010.12.037 . .