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  1. Article: Epidemiological control measures and predicted number of infections for SARS-CoV-2 pandemic: case study Serbia march-april 2020.

    Djurović, Igor

    Heliyon

    2020  Volume 6, Issue 6, Page(s) e04238

    Abstract: Background: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15: Methods: We have performed extrapolation of the number of ... ...

    Abstract Background: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15
    Methods: We have performed extrapolation of the number of SARS-CoV-2 infections with the first stable set of data exploiting exponential growth (linear in logarithmic scale). Based on obtained coefficients it is performed prediction of a number of cases until the end of March. After initial exponential growth, we have changed predictive model to the generalized gamma function. Obtained results are compared with the number of infections and the prediction for the remainder of the outbreak is given.
    Findings: We have found that the daily growth rate was above 21.5% at the beginning of the period, increased slightly after the introduction of the State of Emergency and the first set of strict epidemical control measures. It took about 13 days after the first set of strict measures to smooth daily growth. It seems that early government measures had an only moderate impact to reduce growth due to the social behavior of citizens and influx of diaspora returning to Serbia from highly affected areas, i.e., the exponential growth of infected persons is kept but with a reduced slope of about 14-15%. Anyway, it is demonstrated that period required that any measure has effect is up to 15 days after introduction, firstly to exponential growth with a smaller rate and after to smooth function representing the number of infected persons below exponential growth rate.
    Conclusions: Obtained results are consistent with findings from other countries, i.e., initial exponential growth slows down within the presumed incubation period of 2 weeks after adopting lockdown and other non-pharmaceutical epidemiological measures. However, it is also shown that the exponential growth can continue after this period with a smaller slope. Therefore, quarantine and other social distancing measures should be adopted as soon as possible in a case of any similar outbreak since alternatives mean prolonged epidemical situation and growing costs in human life, pressure on the health system, economy, etc. For modeling the remainder of the outbreak generalized gamma function is used showing accurate results but requiring more samples and pre-processing (data filtering) concerning exponential part of the outbreak. We have estimated the number of infected persons for the remaining part of the outbreak until the end of June.
    Keywords covid19
    Language English
    Publishing date 2020-06-17
    Publishing country England
    Document type Journal Article
    ZDB-ID 2835763-2
    ISSN 2405-8440
    ISSN 2405-8440
    DOI 10.1016/j.heliyon.2020.e04238
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Epidemiological control measures and predicted number of infections for SARS-CoV-2 pandemic

    Igor Djurović

    Heliyon, Vol 6, Iss 6, Pp e04238- (2020)

    case study Serbia march–april 2020

    2020  

    Abstract: Background: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15th and Apr. 15th, 2020 by predictive numerical models. Such a ... ...

    Abstract Background: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15th and Apr. 15th, 2020 by predictive numerical models. Such a study should be helpful to access the effectiveness of measures conducted to suppress the pandemic at a local scale. Methods: We have performed extrapolation of the number of SARS-CoV-2 infections with the first stable set of data exploiting exponential growth (linear in logarithmic scale). Based on obtained coefficients it is performed prediction of a number of cases until the end of March. After initial exponential growth, we have changed predictive model to the generalized gamma function. Obtained results are compared with the number of infections and the prediction for the remainder of the outbreak is given. Findings: We have found that the daily growth rate was above 21.5% at the beginning of the period, increased slightly after the introduction of the State of Emergency and the first set of strict epidemical control measures. It took about 13 days after the first set of strict measures to smooth daily growth. It seems that early government measures had an only moderate impact to reduce growth due to the social behavior of citizens and influx of diaspora returning to Serbia from highly affected areas, i.e., the exponential growth of infected persons is kept but with a reduced slope of about 14–15%. Anyway, it is demonstrated that period required that any measure has effect is up to 15 days after introduction, firstly to exponential growth with a smaller rate and after to smooth function representing the number of infected persons below exponential growth rate. Conclusions: Obtained results are consistent with findings from other countries, i.e., initial exponential growth slows down within the presumed incubation period of 2 weeks after adopting lockdown and other non-pharmaceutical epidemiological measures. However, it is also shown that the exponential growth ...
    Keywords Epidemiology ; Infectious disease ; Public health ; SARS-CoV-2 ; Serbia ; Prediction model ; Science (General) ; Q1-390 ; Social sciences (General) ; H1-99 ; covid19
    Subject code 300
    Language English
    Publishing date 2020-06-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Epidemiological control measures and predicted number of infections for SARS-CoV-2 pandemic

    Djurović, Igor

    Heliyon

    case study Serbia march–april 2020

    2020  Volume 6, Issue 6, Page(s) e04238

    Keywords covid19
    Language English
    Publisher Elsevier BV
    Publishing country us
    Document type Article ; Online
    ZDB-ID 2835763-2
    ISSN 2405-8440
    ISSN 2405-8440
    DOI 10.1016/j.heliyon.2020.e04238
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article: Epidemiological control measures and predicted number of infections for SARS-CoV-2 pandemic: case study Serbia march–april 2020

    Djurović, Igor

    Heliyon. 2020 June, v. 6, no. 6

    2020  

    Abstract: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15ᵗʰ and Apr. 15ᵗʰ, 2020 by predictive numerical models. Such a study should be ... ...

    Abstract In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15ᵗʰ and Apr. 15ᵗʰ, 2020 by predictive numerical models. Such a study should be helpful to access the effectiveness of measures conducted to suppress the pandemic at a local scale.We have performed extrapolation of the number of SARS-CoV-2 infections with the first stable set of data exploiting exponential growth (linear in logarithmic scale). Based on obtained coefficients it is performed prediction of a number of cases until the end of March. After initial exponential growth, we have changed predictive model to the generalized gamma function. Obtained results are compared with the number of infections and the prediction for the remainder of the outbreak is given.We have found that the daily growth rate was above 21.5% at the beginning of the period, increased slightly after the introduction of the State of Emergency and the first set of strict epidemical control measures. It took about 13 days after the first set of strict measures to smooth daily growth. It seems that early government measures had an only moderate impact to reduce growth due to the social behavior of citizens and influx of diaspora returning to Serbia from highly affected areas, i.e., the exponential growth of infected persons is kept but with a reduced slope of about 14–15%. Anyway, it is demonstrated that period required that any measure has effect is up to 15 days after introduction, firstly to exponential growth with a smaller rate and after to smooth function representing the number of infected persons below exponential growth rate.Obtained results are consistent with findings from other countries, i.e., initial exponential growth slows down within the presumed incubation period of 2 weeks after adopting lockdown and other non-pharmaceutical epidemiological measures. However, it is also shown that the exponential growth can continue after this period with a smaller slope. Therefore, quarantine and other social distancing measures should be adopted as soon as possible in a case of any similar outbreak since alternatives mean prolonged epidemical situation and growing costs in human life, pressure on the health system, economy, etc. For modeling the remainder of the outbreak generalized gamma function is used showing accurate results but requiring more samples and pre-processing (data filtering) concerning exponential part of the outbreak. We have estimated the number of infected persons for the remaining part of the outbreak until the end of June.
    Keywords Severe acute respiratory syndrome coronavirus 2 ; case studies ; humans ; pandemic ; prediction ; quarantine ; social behavior ; Serbia
    Language English
    Dates of publication 2020-06
    Publishing place Elsevier Ltd
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 2835763-2
    ISSN 2405-8440
    ISSN 2405-8440
    DOI 10.1016/j.heliyon.2020.e04238
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: Epidemiological control measures and predicted number of infections for SARS-CoV-2 pandemic: case study Serbia march–april 2020

    Djurović, Igor

    Heliyon

    Abstract: Background: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15 thand Apr. 15 th, 2020 by predictive numerical models. Such a ... ...

    Abstract Background: In this paper, we are studying the response of the Serbian government and health authorities to the SARS-CoV-2 pandemic in the early stage of the local outbreak between Mar. 15 thand Apr. 15 th, 2020 by predictive numerical models. Such a study should be helpful to access the effectiveness of measures conducted to suppress the pandemic at a local scale. Methods: We have performed extrapolation of the number of SARS-CoV-2 infections with the first stable set of data exploiting exponential growth (linear in logarithmic scale). Based on obtained coefficients it is performed prediction of a number of cases until the end of March. After initial exponential growth, we have changed predictive model to the generalized gamma function. Obtained results are compared with the number of infections and the prediction for the remainder of the outbreak is given. Findings: We have found that the daily growth rate was above 21.5% at the beginning of the period, increased slightly after the introduction of the State of Emergency and the first set of strict epidemical control measures. It took about 13 days after the first set of strict measures to smooth daily growth. It seems that early government measures had an only moderate impact to reduce growth due to the social behavior of citizens and influx of diaspora returning to Serbia from highly affected areas, i.e., the exponential growth of infected persons is kept but with a reduced slope of about 14–15%. Anyway, it is demonstrated that period required that any measure has effect is up to 15 days after introduction, firstly to exponential growth with a smaller rate and after to smooth function representing the number of infected persons below exponential growth rate. Conclusions: Obtained results are consistent with findings from other countries, i.e., initial exponential growth slows down within the presumed incubation period of 2 weeks after adopting lockdown and other non-pharmaceutical epidemiological measures. However, it is also shown that the exponential growth can continue after this period with a smaller slope. Therefore, quarantine and other social distancing measures should be adopted as soon as possible in a case of any similar outbreak since alternatives mean prolonged epidemical situation and growing costs in human life, pressure on the health system, economy, etc. For modeling the remainder of the outbreak generalized gamma function is used showing accurate results but requiring more samples and pre-processing (data filtering) concerning exponential part of the outbreak. We have estimated the number of infected persons for the remaining part of the outbreak until the end of June.
    Keywords covid19
    Publisher WHO
    Document type Article
    Note WHO #Covidence: #601422
    Database COVID19

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  6. Article ; Online: Estimating the Instantaneous Frequency of Linear and Nonlinear Frequency Modulated Radar Signals-A Comparative Study.

    Milczarek, Hubert / Leśnik, Czesław / Djurović, Igor / Kawalec, Adam

    Sensors (Basel, Switzerland)

    2021  Volume 21, Issue 8

    Abstract: Automatic modulation recognition plays a vital role in electronic warfare. Modern electronic intelligence and electronic support measures systems are able to automatically distinguish the modulation type of an intercepted radar signal by means of real- ... ...

    Abstract Automatic modulation recognition plays a vital role in electronic warfare. Modern electronic intelligence and electronic support measures systems are able to automatically distinguish the modulation type of an intercepted radar signal by means of real-time intra-pulse analysis. This extra information can facilitate deinterleaving process as well as be utilized in early warning systems or give better insight into the performance of hostile radars. Existing modulation recognition algorithms usually extract signal features from one of the rudimentary waveform characteristics, namely instantaneous frequency (IF). Currently, there are a small number of studies concerning IF estimation methods, specifically for radar signals, whereas estimator accuracy may adversely affect the performance of the whole classification process. In this paper, five popular methods of evaluating the IF-law of frequency modulated radar signals are compared. The considered algorithms incorporate the two most prevalent estimation techniques, i.e., phase finite differences and time-frequency representations. The novel approach based on the generalized quasi-maximum likelihood (QML) method is also proposed. The results of simulation experiments show that the proposed QML estimator is significantly more accurate than the other considered techniques. Furthermore, for the first time in the publicly available literature, multipath influence on IF estimates has been investigated.
    Language English
    Publishing date 2021-04-17
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2052857-7
    ISSN 1424-8220 ; 1424-8220
    ISSN (online) 1424-8220
    ISSN 1424-8220
    DOI 10.3390/s21082840
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Book: The Boka Kotorska Bay environment

    Anačkov, Goran / Joksimović, Aleksandar / Djurović, Mirko / Semenov, Aleksander V. / Zonn, Igorʹ Sergeevič / Kostjanoj, Andrej Gennadʹevič

    (The handbook of environmental chemistry ; volume 54)

    2017  

    Author's details volume editors: Aleksandar Joksimović, Mirko Djurović, Aleksander V. Semenov, Igor S. Zonn, Andrey G. Kostianoy ; with contributions by G. Anačkov [und vielen anderen]
    Series title The handbook of environmental chemistry ; volume 54
    Collection
    Keywords Adriatic Sea ; Bay of Kotor ; Ecotoxicology ; Marine chemistry ; Marine pollution ; Phytobenthos ; Boka Kotorska ; Ökosystem ; Ökologische Chemie
    Subject Umwelt ; Umweltchemie ; Ökochemie ; Umweltwissenschaften ; Biosystem ; Ökosysteme
    Subject code 333.7
    Language English
    Size xvii, 606 Seiten, Illustrationen, Diagramme, Karten, 23.5 cm x 15.5 cm, 0 g
    Publisher Springer
    Publishing place Cham
    Publishing country Switzerland
    Document type Book
    HBZ-ID HT019302121
    ISBN 978-3-319-51613-4 ; 3-319-51613-2 ; 9783319516141 ; 3319516140
    Database Catalogue ZB MED Nutrition, Environment, Agriculture

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  8. Article ; Online: LOW SNR TRESHOLD IN RAPID ESTIMATORS OF COMPLEX SINUSOIDALS

    Igor Djurovic / Vladimir V. Lukin

    Радіоелектронні і комп'ютерні системи, Vol 0, Iss 2, Pp 20-

    2019  Volume 25

    Abstract: A task of estimation of complex sinusoid frequency is considered. A particular but practically important case of low signal-to-noise ratio (SNR) is studied. The low SNR threshold, commonly overlooked in development of the rapid estimator of complex ... ...

    Abstract A task of estimation of complex sinusoid frequency is considered. A particular but practically important case of low signal-to-noise ratio (SNR) is studied. The low SNR threshold, commonly overlooked in development of the rapid estimator of complex sinusoidals, is addressed. Signals of different length are considered and SNR is varied in wide limits. It is demonstrated that a simple interpolation with factor 2 lowers the SNR threshold by 1.5dB for the most complicated practical situations. Further interpolation does not bring any improvement. This allows proposing a compromise practical algorithm that provides accuracy close to the limit and is still very simple and fast.
    Keywords дпф ; оцінювання частоти ; поріг всш ; Computer engineering. Computer hardware ; TK7885-7895 ; Electronic computers. Computer science ; QA75.5-76.95
    Language English
    Publishing date 2019-09-01T00:00:00Z
    Publisher National Aerospace University «Kharkiv Aviation Institute»
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Influence of Implant Impression Methods, Polymer Materials, and Implant Angulation on the Accuracy of Dental Models.

    Djurovic Koprivica, Daniela / Puskar, Tatjana / Budak, Igor / Sokac, Mario / Jeremic Knezevic, Milica / Maletin, Aleksandra / Milekic, Bojana / Vukelic, Djordje

    Polymers

    2022  Volume 14, Issue 14

    Abstract: The paper presents the influence of impression methods, polymer materials, and implant angulation on the accuracy of the definitive working model for the production of implant-supported dental restorations, based on the analysis of results obtained using ...

    Abstract The paper presents the influence of impression methods, polymer materials, and implant angulation on the accuracy of the definitive working model for the production of implant-supported dental restorations, based on the analysis of results obtained using different impression methods, materials, and parallel and angulated implants. The study findings indicate that all aforementioned factors impact the accuracy of the definitive working model. Specifically, 20° implant angulation in relation to the vertical plane has a greater impact on the impression accuracy compared to parallel implants. The open and splint method in combination with addition silicone, as well as the splint method and polyether combination yielded more accurate results when using implants under 20° angulation compared to other method and material combinations. The splint method in combination with addition silicone resulted in the smallest mean deviations from the center of the parallel implant base compared to other combinations of methods and materials. Analysis results further revealed statistically significant differences in the measured indicators across impression methods, implants, and polymer materials.
    Language English
    Publishing date 2022-07-11
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527146-5
    ISSN 2073-4360 ; 2073-4360
    ISSN (online) 2073-4360
    ISSN 2073-4360
    DOI 10.3390/polym14142821
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Nonparametric algorithm for local frequency estimation of multidimensional signals.

    Djurović, Igor / Stanković, Ljubisa

    IEEE transactions on image processing : a publication of the IEEE Signal Processing Society

    2004  Volume 13, Issue 4, Page(s) 467–474

    Abstract: Local frequency (LF) estimation of multidimensional (md) signals is considered. The md-Wigner distribution (WD) is used as the LF estimator. The LF is estimated based on the positions of the WD maxima. A nonparametric algorithm for the LF estimation is ... ...

    Abstract Local frequency (LF) estimation of multidimensional (md) signals is considered. The md-Wigner distribution (WD) is used as the LF estimator. The LF is estimated based on the positions of the WD maxima. A nonparametric algorithm for the LF estimation is developed. It is based on the intersection of confidence intervals rule. This algorithm produces an adaptive window size in the WD which gives almost minimal mean squared error of the estimate. A simplified version of this algorithm is developed, with the starting estimate being produced with the WD of one-dimensional signals. Theory is illustrated in examples.
    MeSH term(s) Algorithms ; Artificial Intelligence ; Feedback ; Image Enhancement/methods ; Image Interpretation, Computer-Assisted/methods ; Information Storage and Retrieval/methods ; Pattern Recognition, Automated ; Reproducibility of Results ; Sensitivity and Specificity ; Signal Processing, Computer-Assisted
    Language English
    Publishing date 2004-09-08
    Publishing country United States
    Document type Comparative Study ; Evaluation Studies ; Journal Article ; Research Support, Non-U.S. Gov't ; Validation Studies
    ISSN 1057-7149
    ISSN 1057-7149
    DOI 10.1109/tip.2004.823824
    Database MEDical Literature Analysis and Retrieval System OnLINE

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