TY  - JOUR
AU  - Nikezić, Dušan P.
AU  - Radivojević, Dušan S.
AU  - Lazović, Ivan
AU  - Mirkov, Nikola S.
AU  - Marković, Zoran J.
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12988
AB  - In order to better predict the high aerosol concentrations associated with air pollution and climate change, a machine learning model was developed using transfer learning and the segmentation process of global satellite images. The main concept of transfer learning lies on convolutional neural networks and works by initializing the already trained model weights to better adapt the weights when the network is trained on a different dataset. The transfer learning technique was tested with the ResNet3D-101 model pre-trained from a 2D ImageNet dataset. This model has performed well for contrail detection to assess climate impact. Aerosol distributions can be monitored via satellite remote sensing. Satellites can monitor some aerosol optical properties like aerosol optical thickness. Aerosol optical thickness snapshots were the input dataset for the model and were obtained from NASA’s Terra-Modis satellite; the output images were segmented by comparing the pixel values with a threshold value of 0.8 for aerosol optical thickness. Hyperparameter optimization finds a tuple of hyperparameters that yields an optimal model that minimizes a predefined loss function on given independent data. The model structure was adjusted in order to improve the performance of the model by applying methods and hyperparameter optimization techniques such as grid search, batch size, threshold, and input length. According to the criteria defined by the authors, the distance domain criterion and time domain criterion, the developed model is capable of generating adequate data and finding patterns in the time domain. As observed from the comparison of relative coefficients for the criteria metrics proposed by the authors, ddc and dtc, the deep learning model based on ConvLSTM layers developed in our previous studies has better performance than the model developed in this study with transfer learning.
T2  - Mathematics
T1  - Transfer Learning with ResNet3D-101 for Global Prediction of High Aerosol Concentrations
VL  - 12
IS  - 6
SP  - 826
DO  - 10.3390/math12060826
ER  - 

@article{
author = "Nikezić, Dušan P. and Radivojević, Dušan S. and Lazović, Ivan and Mirkov, Nikola S. and Marković, Zoran J.",
year = "2024",
abstract = "In order to better predict the high aerosol concentrations associated with air pollution and climate change, a machine learning model was developed using transfer learning and the segmentation process of global satellite images. The main concept of transfer learning lies on convolutional neural networks and works by initializing the already trained model weights to better adapt the weights when the network is trained on a different dataset. The transfer learning technique was tested with the ResNet3D-101 model pre-trained from a 2D ImageNet dataset. This model has performed well for contrail detection to assess climate impact. Aerosol distributions can be monitored via satellite remote sensing. Satellites can monitor some aerosol optical properties like aerosol optical thickness. Aerosol optical thickness snapshots were the input dataset for the model and were obtained from NASA’s Terra-Modis satellite; the output images were segmented by comparing the pixel values with a threshold value of 0.8 for aerosol optical thickness. Hyperparameter optimization finds a tuple of hyperparameters that yields an optimal model that minimizes a predefined loss function on given independent data. The model structure was adjusted in order to improve the performance of the model by applying methods and hyperparameter optimization techniques such as grid search, batch size, threshold, and input length. According to the criteria defined by the authors, the distance domain criterion and time domain criterion, the developed model is capable of generating adequate data and finding patterns in the time domain. As observed from the comparison of relative coefficients for the criteria metrics proposed by the authors, ddc and dtc, the deep learning model based on ConvLSTM layers developed in our previous studies has better performance than the model developed in this study with transfer learning.",
journal = "Mathematics",
title = "Transfer Learning with ResNet3D-101 for Global Prediction of High Aerosol Concentrations",
volume = "12",
number = "6",
pages = "826",
doi = "10.3390/math12060826"
}

Nikezić, D. P., Radivojević, D. S., Lazović, I., Mirkov, N. S.,& Marković, Z. J.. (2024). Transfer Learning with ResNet3D-101 for Global Prediction of High Aerosol Concentrations. in Mathematics, 12(6), 826.
https://doi.org/10.3390/math12060826

Nikezić DP, Radivojević DS, Lazović I, Mirkov NS, Marković ZJ. Transfer Learning with ResNet3D-101 for Global Prediction of High Aerosol Concentrations. in Mathematics. 2024;12(6):826.
doi:10.3390/math12060826 .

Nikezić, Dušan P., Radivojević, Dušan S., Lazović, Ivan, Mirkov, Nikola S., Marković, Zoran J., "Transfer Learning with ResNet3D-101 for Global Prediction of High Aerosol Concentrations" in Mathematics, 12, no. 6 (2024):826,
https://doi.org/10.3390/math12060826 . .

TY  - JOUR
AU  - Stojiljković, Vuk
AU  - Mirkov, Nikola
AU  - Radenović, Stojan
PY  - 2024
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/12722
AB  - In this paper, various tensorial inequalities of trapezoid type were obtained. Identity from classical analysis is utilized to obtain the tensorial version of the said identity which in turn allowed us to obtain tensorial inequalities in Hilbert space. The continuous functions of self-adjoint operators in Hilbert spaces have several tensorial norm inequalities discovered in this study. The convexity features of the mapping f lead to the variation in several inequalities of the trapezoid type.
T2  - Symmetry
T1  - Variations in the Tensorial Trapezoid Type Inequalities for Convex Functions of Self-Adjoint Operators in Hilbert Spaces
VL  - 16
IS  - 1
SP  - 121
DO  - 10.3390/sym16010121
ER  - 

@article{
author = "Stojiljković, Vuk and Mirkov, Nikola and Radenović, Stojan",
year = "2024",
abstract = "In this paper, various tensorial inequalities of trapezoid type were obtained. Identity from classical analysis is utilized to obtain the tensorial version of the said identity which in turn allowed us to obtain tensorial inequalities in Hilbert space. The continuous functions of self-adjoint operators in Hilbert spaces have several tensorial norm inequalities discovered in this study. The convexity features of the mapping f lead to the variation in several inequalities of the trapezoid type.",
journal = "Symmetry",
title = "Variations in the Tensorial Trapezoid Type Inequalities for Convex Functions of Self-Adjoint Operators in Hilbert Spaces",
volume = "16",
number = "1",
pages = "121",
doi = "10.3390/sym16010121"
}

Stojiljković, V., Mirkov, N.,& Radenović, S.. (2024). Variations in the Tensorial Trapezoid Type Inequalities for Convex Functions of Self-Adjoint Operators in Hilbert Spaces. in Symmetry, 16(1), 121.
https://doi.org/10.3390/sym16010121

Stojiljković V, Mirkov N, Radenović S. Variations in the Tensorial Trapezoid Type Inequalities for Convex Functions of Self-Adjoint Operators in Hilbert Spaces. in Symmetry. 2024;16(1):121.
doi:10.3390/sym16010121 .

Stojiljković, Vuk, Mirkov, Nikola, Radenović, Stojan, "Variations in the Tensorial Trapezoid Type Inequalities for Convex Functions of Self-Adjoint Operators in Hilbert Spaces" in Symmetry, 16, no. 1 (2024):121,
https://doi.org/10.3390/sym16010121 . .

Tasić, V., Kovačević, R., Apostolovski-Trujić, T., Lazović, I., Mirkov, N., Topalović, D., Božilov, A.,& Mišić, N.. (2023). Uređaj za merenje kvaliteta vazduha - PAQMAN 2020. in Univerzitet u Beogradu : Institut za nuklearne nauke "Vinča" - Institut od nacionalnog značaja za Republiku Srbiju.
https://hdl.handle.net/21.15107/rcub_vinar_13000

Tasić V, Kovačević R, Apostolovski-Trujić T, Lazović I, Mirkov N, Topalović D, Božilov A, Mišić N. Uređaj za merenje kvaliteta vazduha - PAQMAN 2020. in Univerzitet u Beogradu : Institut za nuklearne nauke "Vinča" - Institut od nacionalnog značaja za Republiku Srbiju. 2023;.
https://hdl.handle.net/21.15107/rcub_vinar_13000 .

Tasić, Viša, Kovačević, Renata, Apostolovski-Trujić, Tatjana, Lazović, Ivan, Mirkov, Nikola, Topalović, Dušan, Božilov, Aca, Mišić, Nikola, "Uređaj za merenje kvaliteta vazduha - PAQMAN 2020" in Univerzitet u Beogradu : Institut za nuklearne nauke "Vinča" - Institut od nacionalnog značaja za Republiku Srbiju (2023),
https://hdl.handle.net/21.15107/rcub_vinar_13000 .

TY  - JOUR
AU  - Radivojević, Dušan S.
AU  - Lazović, Ivan
AU  - Mirkov, Nikola S.
AU  - Ramadani, Uzahir
AU  - Nikezić, Dušan P.
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10871
AB  - The attention mechanism in natural language processing and self-attention mechanism in vision transformers improved many deep learning models. An implementation of the self-attention mechanism with the previously developed ConvLSTM sequence-to-one model was done in order to make a comparative evaluation with statistical testing. First, the new ConvLSTM sequence-to-one model with a self-attention mechanism was developed and then the self-attention layer was removed in order to make comparison. The hyperparameters optimization process was conducted by grid search for integer and string type parameters, and with particle swarm optimization for float type parameters. A cross validation technique was used for better evaluating models with a predefined ratio of train-validation-test subsets. Both models with and without a self-attention layer passed defined evaluation criteria that means that models are able to generate the image of the global aerosol thickness and able to find patterns for changes in the time domain. The model obtained by an ablation study on the self-attention layer achieved better outcomes for Root Mean Square Error and Euclidean Distance in regards to developed ConvLSTM-SA model. As part of the statistical test, a Kruskal–Wallis H Test was done since it was determined that the data did not belong to the normal distribution and the obtained results showed that both models, with and without the SA layer, predict similar images with patterns at the pixel level to the original dataset. However, the model without the SA layer was more similar to the original dataset especially in the time domain at the pixel level. Based on the comparative evaluation with statistical testing, it was concluded that the developed ConvLSTM-SA model better predicts without an SA layer.
T2  - Mathematics
T1  - A Comparative Evaluation of Self-Attention Mechanism with ConvLSTM Model for Global Aerosol Time Series Forecasting
VL  - 11
IS  - 7
SP  - 1744
DO  - 10.3390/math11071744
ER  - 

@article{
author = "Radivojević, Dušan S. and Lazović, Ivan and Mirkov, Nikola S. and Ramadani, Uzahir and Nikezić, Dušan P.",
year = "2023",
abstract = "The attention mechanism in natural language processing and self-attention mechanism in vision transformers improved many deep learning models. An implementation of the self-attention mechanism with the previously developed ConvLSTM sequence-to-one model was done in order to make a comparative evaluation with statistical testing. First, the new ConvLSTM sequence-to-one model with a self-attention mechanism was developed and then the self-attention layer was removed in order to make comparison. The hyperparameters optimization process was conducted by grid search for integer and string type parameters, and with particle swarm optimization for float type parameters. A cross validation technique was used for better evaluating models with a predefined ratio of train-validation-test subsets. Both models with and without a self-attention layer passed defined evaluation criteria that means that models are able to generate the image of the global aerosol thickness and able to find patterns for changes in the time domain. The model obtained by an ablation study on the self-attention layer achieved better outcomes for Root Mean Square Error and Euclidean Distance in regards to developed ConvLSTM-SA model. As part of the statistical test, a Kruskal–Wallis H Test was done since it was determined that the data did not belong to the normal distribution and the obtained results showed that both models, with and without the SA layer, predict similar images with patterns at the pixel level to the original dataset. However, the model without the SA layer was more similar to the original dataset especially in the time domain at the pixel level. Based on the comparative evaluation with statistical testing, it was concluded that the developed ConvLSTM-SA model better predicts without an SA layer.",
journal = "Mathematics",
title = "A Comparative Evaluation of Self-Attention Mechanism with ConvLSTM Model for Global Aerosol Time Series Forecasting",
volume = "11",
number = "7",
pages = "1744",
doi = "10.3390/math11071744"
}

Radivojević, D. S., Lazović, I., Mirkov, N. S., Ramadani, U.,& Nikezić, D. P.. (2023). A Comparative Evaluation of Self-Attention Mechanism with ConvLSTM Model for Global Aerosol Time Series Forecasting. in Mathematics, 11(7), 1744.
https://doi.org/10.3390/math11071744

Radivojević DS, Lazović I, Mirkov NS, Ramadani U, Nikezić DP. A Comparative Evaluation of Self-Attention Mechanism with ConvLSTM Model for Global Aerosol Time Series Forecasting. in Mathematics. 2023;11(7):1744.
doi:10.3390/math11071744 .

Radivojević, Dušan S., Lazović, Ivan, Mirkov, Nikola S., Ramadani, Uzahir, Nikezić, Dušan P., "A Comparative Evaluation of Self-Attention Mechanism with ConvLSTM Model for Global Aerosol Time Series Forecasting" in Mathematics, 11, no. 7 (2023):1744,
https://doi.org/10.3390/math11071744 . .

TY  - JOUR
AU  - Younis, Mudasir
AU  - Mirkov, Nikola S.
AU  - Savić, Ana
AU  - Pantović, Mirjana
AU  - Radenović, Stojan
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11206
AB  - This paper aims to correct recent results on a generalized class of F−contractions in the context of b−metric spaces. The significant work consists of repairing some novel results involving F−contraction within the struc-ture of b-metric spaces. Our objective is to take advan-tage of the property (F 1) instead of the four properties viz. (F 1), (F 2), (F 3) and (F 4) applied in the results of Nazam et al. [“Coincidence and common fixed point theorems for four mappings satisfying (αs, F)−contraction", Nonlinear Anal: Model. Control., vol. 23, no. 5, pp. 664–690, 2018]. Our approach of proving the results uti-lizing only the condition (F 1) enriches, improves, and condenses the proofs of a multitude of results in the ex-isting state-of-art. © 2023 M. Younis et al.
T2  - Cubo
T1  - Some critical remarks on recent results concerning F−contractions in b-metric spaces
VL  - 25
IS  - 1
SP  - 57
EP  - 66
DO  - 10.56754/0719-0646.2501.057
ER  - 

@article{
author = "Younis, Mudasir and Mirkov, Nikola S. and Savić, Ana and Pantović, Mirjana and Radenović, Stojan",
year = "2023",
abstract = "This paper aims to correct recent results on a generalized class of F−contractions in the context of b−metric spaces. The significant work consists of repairing some novel results involving F−contraction within the struc-ture of b-metric spaces. Our objective is to take advan-tage of the property (F 1) instead of the four properties viz. (F 1), (F 2), (F 3) and (F 4) applied in the results of Nazam et al. [“Coincidence and common fixed point theorems for four mappings satisfying (αs, F)−contraction", Nonlinear Anal: Model. Control., vol. 23, no. 5, pp. 664–690, 2018]. Our approach of proving the results uti-lizing only the condition (F 1) enriches, improves, and condenses the proofs of a multitude of results in the ex-isting state-of-art. © 2023 M. Younis et al.",
journal = "Cubo",
title = "Some critical remarks on recent results concerning F−contractions in b-metric spaces",
volume = "25",
number = "1",
pages = "57-66",
doi = "10.56754/0719-0646.2501.057"
}

Younis, M., Mirkov, N. S., Savić, A., Pantović, M.,& Radenović, S.. (2023). Some critical remarks on recent results concerning F−contractions in b-metric spaces. in Cubo, 25(1), 57-66.
https://doi.org/10.56754/0719-0646.2501.057

Younis M, Mirkov NS, Savić A, Pantović M, Radenović S. Some critical remarks on recent results concerning F−contractions in b-metric spaces. in Cubo. 2023;25(1):57-66.
doi:10.56754/0719-0646.2501.057 .

Younis, Mudasir, Mirkov, Nikola S., Savić, Ana, Pantović, Mirjana, Radenović, Stojan, "Some critical remarks on recent results concerning F−contractions in b-metric spaces" in Cubo, 25, no. 1 (2023):57-66,
https://doi.org/10.56754/0719-0646.2501.057 . .

TY  - CHAP
AU  - Fabiano, Nicola
AU  - Mirkov, Nikola S.
AU  - Mitrović, Zoran D.
AU  - Radenović, Stojan
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11359
AB  - We discuss and give some insights on the Collatz conjecture, known as 3N + 1, and Kurepa’s hypothesis on the left factorial. First, the Collatz conjecture is considered and the density of values is compared to Planck’s black body radiation in physics, showing a remarkable agreement between the two. We also briefly discuss a generalization of Collatz conjecture for a generic sequence qN +1 by means of numerical analysis. Then, we give a brief historical excursus and prove in a simple way some properties of Kurepa’s function, also called the left factorial. We introduce Kurepa’s hypothesis, propose a new description, and the relation to Bezout’s parameters and the Diophantine equation. A numerical analysis supports Kurepa’s hypothesis and the conjecture about distribution for Kurepa’s function.
T2  - Advances in Number Theory and Applied Analysis
T1  - Collatz Hypothesis and Kurepa’s Conjecture
SP  - 31
EP  - 50
DO  - 10.1142/9789811272608_0003
ER  - 

@inbook{
author = "Fabiano, Nicola and Mirkov, Nikola S. and Mitrović, Zoran D. and Radenović, Stojan",
year = "2023",
abstract = "We discuss and give some insights on the Collatz conjecture, known as 3N + 1, and Kurepa’s hypothesis on the left factorial. First, the Collatz conjecture is considered and the density of values is compared to Planck’s black body radiation in physics, showing a remarkable agreement between the two. We also briefly discuss a generalization of Collatz conjecture for a generic sequence qN +1 by means of numerical analysis. Then, we give a brief historical excursus and prove in a simple way some properties of Kurepa’s function, also called the left factorial. We introduce Kurepa’s hypothesis, propose a new description, and the relation to Bezout’s parameters and the Diophantine equation. A numerical analysis supports Kurepa’s hypothesis and the conjecture about distribution for Kurepa’s function.",
journal = "Advances in Number Theory and Applied Analysis",
booktitle = "Collatz Hypothesis and Kurepa’s Conjecture",
pages = "31-50",
doi = "10.1142/9789811272608_0003"
}

Fabiano, N., Mirkov, N. S., Mitrović, Z. D.,& Radenović, S.. (2023). Collatz Hypothesis and Kurepa’s Conjecture. in Advances in Number Theory and Applied Analysis, 31-50.
https://doi.org/10.1142/9789811272608_0003

Fabiano N, Mirkov NS, Mitrović ZD, Radenović S. Collatz Hypothesis and Kurepa’s Conjecture. in Advances in Number Theory and Applied Analysis. 2023;:31-50.
doi:10.1142/9789811272608_0003 .

Fabiano, Nicola, Mirkov, Nikola S., Mitrović, Zoran D., Radenović, Stojan, "Collatz Hypothesis and Kurepa’s Conjecture" in Advances in Number Theory and Applied Analysis (2023):31-50,
https://doi.org/10.1142/9789811272608_0003 . .

TY  - JOUR
AU  - Fabiano, Nicola
AU  - Kadelburg, Zoran
AU  - Mirkov, Nikola S.
AU  - Radenović, Stojan
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11360
AB  - In 1964, A. I. Perov generalized the Banach contraction principle introducing, following the work of Đ. Kurepa, a new approach to fixed point problems, by defining generalized metric spaces (also known as vector valued metric spaces), and providing some actual results for the first time. Using the recent approach of coordinate representation for a generalized metric of Jachymski and Klima, we verify in this article some natural properties of generalized metric spaces, already owned by standard metric spaces. Among other results, we show that the theorems of Nemytckii (1936) and Edelstein (1962) are valid in generalized metric spaces, as well. A new application to fractional differential equations is also presented. At the end we state a few open questions for young researchers. © Işık University, Department of Mathematics, 2023; all rights reserved.
T2  - Turkish World Mathematical Society Journal of Applied and Engineering Mathematics
T1  - Solving fractional differential equations using fixed point results in generalized metric spaces of Perov's type
VL  - 13
IS  - 3
SP  - 880
EP  - 890
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11360
ER  - 

@article{
author = "Fabiano, Nicola and Kadelburg, Zoran and Mirkov, Nikola S. and Radenović, Stojan",
year = "2023",
abstract = "In 1964, A. I. Perov generalized the Banach contraction principle introducing, following the work of Đ. Kurepa, a new approach to fixed point problems, by defining generalized metric spaces (also known as vector valued metric spaces), and providing some actual results for the first time. Using the recent approach of coordinate representation for a generalized metric of Jachymski and Klima, we verify in this article some natural properties of generalized metric spaces, already owned by standard metric spaces. Among other results, we show that the theorems of Nemytckii (1936) and Edelstein (1962) are valid in generalized metric spaces, as well. A new application to fractional differential equations is also presented. At the end we state a few open questions for young researchers. © Işık University, Department of Mathematics, 2023; all rights reserved.",
journal = "Turkish World Mathematical Society Journal of Applied and Engineering Mathematics",
title = "Solving fractional differential equations using fixed point results in generalized metric spaces of Perov's type",
volume = "13",
number = "3",
pages = "880-890",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11360"
}

Fabiano, N., Kadelburg, Z., Mirkov, N. S.,& Radenović, S.. (2023). Solving fractional differential equations using fixed point results in generalized metric spaces of Perov's type. in Turkish World Mathematical Society Journal of Applied and Engineering Mathematics, 13(3), 880-890.
https://hdl.handle.net/21.15107/rcub_vinar_11360

Fabiano N, Kadelburg Z, Mirkov NS, Radenović S. Solving fractional differential equations using fixed point results in generalized metric spaces of Perov's type. in Turkish World Mathematical Society Journal of Applied and Engineering Mathematics. 2023;13(3):880-890.
https://hdl.handle.net/21.15107/rcub_vinar_11360 .

Fabiano, Nicola, Kadelburg, Zoran, Mirkov, Nikola S., Radenović, Stojan, "Solving fractional differential equations using fixed point results in generalized metric spaces of Perov's type" in Turkish World Mathematical Society Journal of Applied and Engineering Mathematics, 13, no. 3 (2023):880-890,
https://hdl.handle.net/21.15107/rcub_vinar_11360 .

TY  - JOUR
AU  - Mirkov, Nikola S.
AU  - Fabiano, Nicola
AU  - Radenović, Stojan
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11375
AB  - In this manuscript, among other things, we put some remarks on recently established results by I. Altun et al. on a new fixed point result of Perov type and its application to a semilinear operator system, showing that they can be reduced to the known earlier results of M. Jleli and B. Samet. This follows according to the recent significant paper of J. Jachymski and J. Klima on Perov’s fixed point theorem for mappings on generalized metric spaces. Present approach, therefore, unifies fixed point results in vector valued metric spaces.
T2  - TWMS Journal of pure and applied mathematics
T1  - Critical remarks on a new fixed point result of Perov type and its application to a semilinear operator system
VL  - 14
IS  - 1
SP  - 141
EP  - 145
DO  - 10.30546/2219-1259.14.1.2023.141
ER  - 

@article{
author = "Mirkov, Nikola S. and Fabiano, Nicola and Radenović, Stojan",
year = "2023",
abstract = "In this manuscript, among other things, we put some remarks on recently established results by I. Altun et al. on a new fixed point result of Perov type and its application to a semilinear operator system, showing that they can be reduced to the known earlier results of M. Jleli and B. Samet. This follows according to the recent significant paper of J. Jachymski and J. Klima on Perov’s fixed point theorem for mappings on generalized metric spaces. Present approach, therefore, unifies fixed point results in vector valued metric spaces.",
journal = "TWMS Journal of pure and applied mathematics",
title = "Critical remarks on a new fixed point result of Perov type and its application to a semilinear operator system",
volume = "14",
number = "1",
pages = "141-145",
doi = "10.30546/2219-1259.14.1.2023.141"
}

Mirkov, N. S., Fabiano, N.,& Radenović, S.. (2023). Critical remarks on a new fixed point result of Perov type and its application to a semilinear operator system. in TWMS Journal of pure and applied mathematics, 14(1), 141-145.
https://doi.org/10.30546/2219-1259.14.1.2023.141

Mirkov NS, Fabiano N, Radenović S. Critical remarks on a new fixed point result of Perov type and its application to a semilinear operator system. in TWMS Journal of pure and applied mathematics. 2023;14(1):141-145.
doi:10.30546/2219-1259.14.1.2023.141 .

Mirkov, Nikola S., Fabiano, Nicola, Radenović, Stojan, "Critical remarks on a new fixed point result of Perov type and its application to a semilinear operator system" in TWMS Journal of pure and applied mathematics, 14, no. 1 (2023):141-145,
https://doi.org/10.30546/2219-1259.14.1.2023.141 . .

TY  - CHAP
AU  - Mirkov, Nikola S.
AU  - Ouyahia, Seif Eddine
AU  - Lahlou, Sara
AU  - Pezo, Milada L.
AU  - Jovanović, Rastko D.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10065
AB  - In the present paper, we discuss implementation details of a free and open-source numerical solver based on the finite volume method for numerical simulation of viscoplastic non-Newtonian fluids. In addition to the fact that they are involved in many industrial applications, both their physical properties and their rheological behavior make them challenging for numerical simulation. Viscoplastic fluids are known to behave as solid unless the shear stress reaches a critical level, known as yield-stress, beyond which they behave as liquid. In most cases, both yielded and unyielded regions coexist in the fluid domain. In mathematical model of viscoplastic fluid, the constitutive equation is a non-differentiable function. This is often overcome by using the approximate constitutive equation that has a regularized form, e.g. the Papanastasiou regularization model. Using the same approach, we assess the influence of regularization parameters on simulation convergence and results accuracy. In this study, we give implementation details of viscoplastic fluid models in freeCappuccino open-source Computational Fluid Dynamics code. Moreover, we perform validation on several well known benchmark cases and compare proposed approach with those existing in published literature. We also perform a parametric analysis and show the effect of Reynolds and Bingham numbers on the extent of the yielded regions. Conclusions of the study have relevance in practical application of computational fluid dynamics to viscoplastic fluids in particular and to non-Newtonian fluids in general. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
T2  - Lecture Notes in Networks and Systems
T1  - Development and Validation of an Open-Source Finite-Volume Method Solver for Viscoplastic Flows
VL  - 323
SP  - 223
EP  - 238
DO  - 10.1007/978-3-030-86009-7_12
ER  - 

@inbook{
author = "Mirkov, Nikola S. and Ouyahia, Seif Eddine and Lahlou, Sara and Pezo, Milada L. and Jovanović, Rastko D.",
year = "2022",
abstract = "In the present paper, we discuss implementation details of a free and open-source numerical solver based on the finite volume method for numerical simulation of viscoplastic non-Newtonian fluids. In addition to the fact that they are involved in many industrial applications, both their physical properties and their rheological behavior make them challenging for numerical simulation. Viscoplastic fluids are known to behave as solid unless the shear stress reaches a critical level, known as yield-stress, beyond which they behave as liquid. In most cases, both yielded and unyielded regions coexist in the fluid domain. In mathematical model of viscoplastic fluid, the constitutive equation is a non-differentiable function. This is often overcome by using the approximate constitutive equation that has a regularized form, e.g. the Papanastasiou regularization model. Using the same approach, we assess the influence of regularization parameters on simulation convergence and results accuracy. In this study, we give implementation details of viscoplastic fluid models in freeCappuccino open-source Computational Fluid Dynamics code. Moreover, we perform validation on several well known benchmark cases and compare proposed approach with those existing in published literature. We also perform a parametric analysis and show the effect of Reynolds and Bingham numbers on the extent of the yielded regions. Conclusions of the study have relevance in practical application of computational fluid dynamics to viscoplastic fluids in particular and to non-Newtonian fluids in general. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.",
journal = "Lecture Notes in Networks and Systems",
booktitle = "Development and Validation of an Open-Source Finite-Volume Method Solver for Viscoplastic Flows",
volume = "323",
pages = "223-238",
doi = "10.1007/978-3-030-86009-7_12"
}

Mirkov, N. S., Ouyahia, S. E., Lahlou, S., Pezo, M. L.,& Jovanović, R. D.. (2022). Development and Validation of an Open-Source Finite-Volume Method Solver for Viscoplastic Flows. in Lecture Notes in Networks and Systems, 323, 223-238.
https://doi.org/10.1007/978-3-030-86009-7_12

Mirkov NS, Ouyahia SE, Lahlou S, Pezo ML, Jovanović RD. Development and Validation of an Open-Source Finite-Volume Method Solver for Viscoplastic Flows. in Lecture Notes in Networks and Systems. 2022;323:223-238.
doi:10.1007/978-3-030-86009-7_12 .

Mirkov, Nikola S., Ouyahia, Seif Eddine, Lahlou, Sara, Pezo, Milada L., Jovanović, Rastko D., "Development and Validation of an Open-Source Finite-Volume Method Solver for Viscoplastic Flows" in Lecture Notes in Networks and Systems, 323 (2022):223-238,
https://doi.org/10.1007/978-3-030-86009-7_12 . .

TY  - JOUR
AU  - Pezo, Milada L.
AU  - Mirkov, Nikola S.
AU  - Bakić, Vukman
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10176
AB  - The power transmitters, guyed masts and other lattice structures are exposed to wind action. The aerodynamic forces acting on tall tower constructions have crucial importance on the stability of the structure. The lattice structure drag coefficient determination is the subject of the international standards ESDU 81027 and 81028 and Eurocode 3 Part 3.1, but it can also be determined by numerical methods. For that purpose modelling using CFD proved to be both accurate and reliable. In this study the fluid-flow around the segment of a power transmitter was simulated by a 3-D model, where the geometry of the segment is approximated with a porous structure having the appropriate factor of porosity, in order to simplify the geometry. We have used three representative models of turbulence, standard k-? model, RNG k-? model, and Reynolds stress model. Drag coefficient values are extracted from the flow field and compared for all studied cases and with available experimental results from the wind tunnel. Simulations were performed for four wind velocities between 10 m/s and 30 m/s. The results are supplemented by the ones obtained by artificial neural network. The aim of this study is to show how the simple turbulence model coupled with approximated geometry can be used in the analysis of the aerodynamic forces acting on the lattice structure.
T2  - Thermal Science
T1  - Determination of the drag coefficient of lattice structures under wind load using porous media approach
VL  - 26
IS  - 1 Part A
SP  - 309
EP  - 317
DO  - 10.2298/TSCI210511233P
ER  - 

@article{
author = "Pezo, Milada L. and Mirkov, Nikola S. and Bakić, Vukman",
year = "2022",
abstract = "The power transmitters, guyed masts and other lattice structures are exposed to wind action. The aerodynamic forces acting on tall tower constructions have crucial importance on the stability of the structure. The lattice structure drag coefficient determination is the subject of the international standards ESDU 81027 and 81028 and Eurocode 3 Part 3.1, but it can also be determined by numerical methods. For that purpose modelling using CFD proved to be both accurate and reliable. In this study the fluid-flow around the segment of a power transmitter was simulated by a 3-D model, where the geometry of the segment is approximated with a porous structure having the appropriate factor of porosity, in order to simplify the geometry. We have used three representative models of turbulence, standard k-? model, RNG k-? model, and Reynolds stress model. Drag coefficient values are extracted from the flow field and compared for all studied cases and with available experimental results from the wind tunnel. Simulations were performed for four wind velocities between 10 m/s and 30 m/s. The results are supplemented by the ones obtained by artificial neural network. The aim of this study is to show how the simple turbulence model coupled with approximated geometry can be used in the analysis of the aerodynamic forces acting on the lattice structure.",
journal = "Thermal Science",
title = "Determination of the drag coefficient of lattice structures under wind load using porous media approach",
volume = "26",
number = "1 Part A",
pages = "309-317",
doi = "10.2298/TSCI210511233P"
}

Pezo, M. L., Mirkov, N. S.,& Bakić, V.. (2022). Determination of the drag coefficient of lattice structures under wind load using porous media approach. in Thermal Science, 26(1 Part A), 309-317.
https://doi.org/10.2298/TSCI210511233P

Pezo ML, Mirkov NS, Bakić V. Determination of the drag coefficient of lattice structures under wind load using porous media approach. in Thermal Science. 2022;26(1 Part A):309-317.
doi:10.2298/TSCI210511233P .

Pezo, Milada L., Mirkov, Nikola S., Bakić, Vukman, "Determination of the drag coefficient of lattice structures under wind load using porous media approach" in Thermal Science, 26, no. 1 Part A (2022):309-317,
https://doi.org/10.2298/TSCI210511233P . .

TY  - JOUR
AU  - Kojić, Predrag
AU  - Kojić, Jovana
AU  - Pezo, Milada L.
AU  - Krulj, Jelena
AU  - Pezo, Lato
AU  - Mirkov, Nikola S.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10294
AB  - The objective of this study was to investigate the hydrodynamics and the gas-liquid mass transfer coefficient of an external-loop airlift reactor (ELAR). The ELAR was operated in three cases: different inlet velocities of fluids, different alcohols solutions (water, 0.5% methanol, 0.5% ethanol, 0.5% propanol and 0.5% butanol) and different concentration of methanol in solutions (0%, 0.5%, 1%, 2% and 5%). The influence of superficial gas velocity and various diluted alcohol solutions on hydrodynamics and the gas-liquid mass transfer coefficient of the ELAR was studied. Experimentally, the gas hold-up, liquid velocities and volumetric mass transfer coefficient values in the riser and the downcomer were obtained from the literature source. A computational fluid dynamics (CFD) model was developed, based on two-phase flow, investigating different liquids regarding surface tension, assuming the ideal gas flow, applying the finite volume method and Eulerian-Eulerian model. The volumetric mass transfer coefficient was determined using the CFD and artificial neural network model. The effects of liquid parameters and gas velocity on the characteristics of the gas-liquid mass transfer were simulated. These models were compared with the appropriate experimental results. The CFD model successfully simulates the influence of different alcohols regarding the number of C-atoms on hydrodynamics and mass transfer.
T2  - Chemical Industry and Chemical Engineering Quarterly / CICEQ
T1  - Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor
VL  - 28
IS  - 3
SP  - 225
EP  - 235
DO  - 10.2298/CICEQ210522034K
ER  - 

@article{
author = "Kojić, Predrag and Kojić, Jovana and Pezo, Milada L. and Krulj, Jelena and Pezo, Lato and Mirkov, Nikola S.",
year = "2022",
abstract = "The objective of this study was to investigate the hydrodynamics and the gas-liquid mass transfer coefficient of an external-loop airlift reactor (ELAR). The ELAR was operated in three cases: different inlet velocities of fluids, different alcohols solutions (water, 0.5% methanol, 0.5% ethanol, 0.5% propanol and 0.5% butanol) and different concentration of methanol in solutions (0%, 0.5%, 1%, 2% and 5%). The influence of superficial gas velocity and various diluted alcohol solutions on hydrodynamics and the gas-liquid mass transfer coefficient of the ELAR was studied. Experimentally, the gas hold-up, liquid velocities and volumetric mass transfer coefficient values in the riser and the downcomer were obtained from the literature source. A computational fluid dynamics (CFD) model was developed, based on two-phase flow, investigating different liquids regarding surface tension, assuming the ideal gas flow, applying the finite volume method and Eulerian-Eulerian model. The volumetric mass transfer coefficient was determined using the CFD and artificial neural network model. The effects of liquid parameters and gas velocity on the characteristics of the gas-liquid mass transfer were simulated. These models were compared with the appropriate experimental results. The CFD model successfully simulates the influence of different alcohols regarding the number of C-atoms on hydrodynamics and mass transfer.",
journal = "Chemical Industry and Chemical Engineering Quarterly / CICEQ",
title = "Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor",
volume = "28",
number = "3",
pages = "225-235",
doi = "10.2298/CICEQ210522034K"
}

Kojić, P., Kojić, J., Pezo, M. L., Krulj, J., Pezo, L.,& Mirkov, N. S.. (2022). Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor. in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 28(3), 225-235.
https://doi.org/10.2298/CICEQ210522034K

Kojić P, Kojić J, Pezo ML, Krulj J, Pezo L, Mirkov NS. Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor. in Chemical Industry and Chemical Engineering Quarterly / CICEQ. 2022;28(3):225-235.
doi:10.2298/CICEQ210522034K .

Kojić, Predrag, Kojić, Jovana, Pezo, Milada L., Krulj, Jelena, Pezo, Lato, Mirkov, Nikola S., "Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor" in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 28, no. 3 (2022):225-235,
https://doi.org/10.2298/CICEQ210522034K . .

TY  - JOUR
AU  - Hasan, Mohammad Sakib
AU  - Svorcan, Jelena M.
AU  - Simonović, Aleksandar M.
AU  - Mirkov, Nikola S.
AU  - Kostić, Olivera P.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10306
AB  - The ability of flying continuously over prolonged periods of time has become target of numerous research studies performed in recent years in both the fields of civil aviation and unmanned drones. High altitude platform stations are aircrafts that can operate for an extended period of time at altitudes 17 km above sea level and higher. The aim of this paper is to design and optimize a wing for such platforms and computationally investigate its aerodynamic performance. For that purpose, two-objective genetic algorithm, class shape transformation and panel method were combined and used to define different airfoils with the highest lift-to-drag ratio and maximal lift coefficient. Once the most suitable airfoil was chosen, polyhedral half-wing was modeled and its aerodynamic performances were estimated using the CFD approach. Flow simulations of transitional flow at various angles-of-attack were realized in ANSYS FLUENT and various quantitative and qualitative results are presented, such as aerodynamic coefficient curves and flow visualizations. In the end, daily mission of the aircraft is simulated and its energy requirement is estimated. In order to be able to cruise above Serbia in July, an aircraft weighing 150 kg must accumulate 17 kWh of solar energy per day.
T2  - Thermal Science
T1  - Optimal airfoil design and wing analysis for solar-powered high altitude platform station
VL  - 26
IS  - 3 Part A
SP  - 2163
EP  - 2175
DO  - 10.2298/TSCI210419241S
ER  - 

@article{
author = "Hasan, Mohammad Sakib and Svorcan, Jelena M. and Simonović, Aleksandar M. and Mirkov, Nikola S. and Kostić, Olivera P.",
year = "2022",
abstract = "The ability of flying continuously over prolonged periods of time has become target of numerous research studies performed in recent years in both the fields of civil aviation and unmanned drones. High altitude platform stations are aircrafts that can operate for an extended period of time at altitudes 17 km above sea level and higher. The aim of this paper is to design and optimize a wing for such platforms and computationally investigate its aerodynamic performance. For that purpose, two-objective genetic algorithm, class shape transformation and panel method were combined and used to define different airfoils with the highest lift-to-drag ratio and maximal lift coefficient. Once the most suitable airfoil was chosen, polyhedral half-wing was modeled and its aerodynamic performances were estimated using the CFD approach. Flow simulations of transitional flow at various angles-of-attack were realized in ANSYS FLUENT and various quantitative and qualitative results are presented, such as aerodynamic coefficient curves and flow visualizations. In the end, daily mission of the aircraft is simulated and its energy requirement is estimated. In order to be able to cruise above Serbia in July, an aircraft weighing 150 kg must accumulate 17 kWh of solar energy per day.",
journal = "Thermal Science",
title = "Optimal airfoil design and wing analysis for solar-powered high altitude platform station",
volume = "26",
number = "3 Part A",
pages = "2163-2175",
doi = "10.2298/TSCI210419241S"
}

Hasan, M. S., Svorcan, J. M., Simonović, A. M., Mirkov, N. S.,& Kostić, O. P.. (2022). Optimal airfoil design and wing analysis for solar-powered high altitude platform station. in Thermal Science, 26(3 Part A), 2163-2175.
https://doi.org/10.2298/TSCI210419241S

Hasan MS, Svorcan JM, Simonović AM, Mirkov NS, Kostić OP. Optimal airfoil design and wing analysis for solar-powered high altitude platform station. in Thermal Science. 2022;26(3 Part A):2163-2175.
doi:10.2298/TSCI210419241S .

Hasan, Mohammad Sakib, Svorcan, Jelena M., Simonović, Aleksandar M., Mirkov, Nikola S., Kostić, Olivera P., "Optimal airfoil design and wing analysis for solar-powered high altitude platform station" in Thermal Science, 26, no. 3 Part A (2022):2163-2175,
https://doi.org/10.2298/TSCI210419241S . .

TY  - JOUR
AU  - Fabiano, Nicola
AU  - Gardašević-Filipović, Milanka
AU  - Mirkov, Nikola S.
AU  - Todorčević, Vesna
AU  - Radenović, Stojan
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10415
AB  - Kurepa’s function and his hypothesis have been investigated by means of numerical simulation. Particular emphasis has been given to the conjecture on its distribution, that should be one of a random uniform distribution, which has been verified for large numbers. A convergence function for the two has been found.
T2  - Axioms
T1  - On the Distribution of Kurepa’s Function
VL  - 11
IS  - 8
SP  - 388
DO  - 10.3390/axioms11080388
ER  - 

@article{
author = "Fabiano, Nicola and Gardašević-Filipović, Milanka and Mirkov, Nikola S. and Todorčević, Vesna and Radenović, Stojan",
year = "2022",
abstract = "Kurepa’s function and his hypothesis have been investigated by means of numerical simulation. Particular emphasis has been given to the conjecture on its distribution, that should be one of a random uniform distribution, which has been verified for large numbers. A convergence function for the two has been found.",
journal = "Axioms",
title = "On the Distribution of Kurepa’s Function",
volume = "11",
number = "8",
pages = "388",
doi = "10.3390/axioms11080388"
}

Fabiano, N., Gardašević-Filipović, M., Mirkov, N. S., Todorčević, V.,& Radenović, S.. (2022). On the Distribution of Kurepa’s Function. in Axioms, 11(8), 388.
https://doi.org/10.3390/axioms11080388

Fabiano N, Gardašević-Filipović M, Mirkov NS, Todorčević V, Radenović S. On the Distribution of Kurepa’s Function. in Axioms. 2022;11(8):388.
doi:10.3390/axioms11080388 .

Fabiano, Nicola, Gardašević-Filipović, Milanka, Mirkov, Nikola S., Todorčević, Vesna, Radenović, Stojan, "On the Distribution of Kurepa’s Function" in Axioms, 11, no. 8 (2022):388,
https://doi.org/10.3390/axioms11080388 . .

TY  - JOUR
AU  - Aranđelović, Nemanja
AU  - Nikezić, Dušan P.
AU  - Ramadani, Uzahir
AU  - Lazović, Ivan
AU  - Mirkov, Nikola S.
AU  - Osmokrović, Predrag V.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10435
AB  - The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field has an extremely high growth rate. At the site of the maximum intensity of the field of non-ionizing radiation, commercial surge arresters with a flexible model of surge arresters were used for experimentation. It has been found that the commercial surge arresters have an efficiency of about 20%. For the efficiency of the flexible model, it was found to be slightly less than 40% (and to be achieved by the application of alpha particle radiation). Since neither of these efficiencies guarantee reliable operation of the gas-filled surge arrester, it was concluded that essential electronics in the vicinity of the fusion generator must be protected. However, since this protection can only be implemented in a fusion reactor, the fact remains that the environment of such a reactor is extremely contaminated with non-ionizing radiation. Commercial surge voltages are isolated for testing since the protection of electronic circuits from fast overvoltages is a critical point for the functioning of modern electronics.
T2  - Nuclear Technology and Radiation Protection
T1  - The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors
VL  - 37
IS  - 1
SP  - 51
EP  - 56
DO  - 10.2298/NTRP2201051A
ER  - 

@article{
author = "Aranđelović, Nemanja and Nikezić, Dušan P. and Ramadani, Uzahir and Lazović, Ivan and Mirkov, Nikola S. and Osmokrović, Predrag V.",
year = "2022",
abstract = "The research presents an experiment with a model of an electronic generator for energy injection into the plasma of a fusion reactor. By recording a non-ionizing field in the vicinity of a fusion reactor, it was determined that this field has an extremely high growth rate. At the site of the maximum intensity of the field of non-ionizing radiation, commercial surge arresters with a flexible model of surge arresters were used for experimentation. It has been found that the commercial surge arresters have an efficiency of about 20%. For the efficiency of the flexible model, it was found to be slightly less than 40% (and to be achieved by the application of alpha particle radiation). Since neither of these efficiencies guarantee reliable operation of the gas-filled surge arrester, it was concluded that essential electronics in the vicinity of the fusion generator must be protected. However, since this protection can only be implemented in a fusion reactor, the fact remains that the environment of such a reactor is extremely contaminated with non-ionizing radiation. Commercial surge voltages are isolated for testing since the protection of electronic circuits from fast overvoltages is a critical point for the functioning of modern electronics.",
journal = "Nuclear Technology and Radiation Protection",
title = "The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors",
volume = "37",
number = "1",
pages = "51-56",
doi = "10.2298/NTRP2201051A"
}

Aranđelović, N., Nikezić, D. P., Ramadani, U., Lazović, I., Mirkov, N. S.,& Osmokrović, P. V.. (2022). The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors. in Nuclear Technology and Radiation Protection, 37(1), 51-56.
https://doi.org/10.2298/NTRP2201051A

Aranđelović N, Nikezić DP, Ramadani U, Lazović I, Mirkov NS, Osmokrović PV. The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors. in Nuclear Technology and Radiation Protection. 2022;37(1):51-56.
doi:10.2298/NTRP2201051A .

Aranđelović, Nemanja, Nikezić, Dušan P., Ramadani, Uzahir, Lazović, Ivan, Mirkov, Nikola S., Osmokrović, Predrag V., "The efficiency of gas-filled surge arresters in the environment contaminated by non-ionizing radiation of fusion reactors" in Nuclear Technology and Radiation Protection, 37, no. 1 (2022):51-56,
https://doi.org/10.2298/NTRP2201051A . .

TY  - JOUR
AU  - Nikezić, Dušan P.
AU  - Ramadani, Uzahir
AU  - Radivojević, Dušan
AU  - Lazović, Ivan
AU  - Mirkov, Nikola S.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10446
AB  - Mathematical methods are the basis of most models that describe the natural phenomena around us. However, the well-known conventional mathematical models for atmospheric modeling have some limitations. Machine learning with Big Data is also based on mathematics but offers a new approach for modeling. There are two methodologies to develop deep learning models for spatio-temporal image prediction. On these bases, two models were built—ConvLSTM and CNN-LSTM—with two types of predictions, i.e., sequence-to-sequence and sequence-to-one, in order to forecast Aerosol Optical Thickness sequences. The input dataset for training was NASA satellite imagery MODAL2_E_AER_OD from Terra/MODIS satellites, which presents global Aerosol Optical Thickness with an 8 day temporal resolution from 2000 to the present. The obtained results show that the ConvLSTM sequence-to-one model had the lowest RMSE error and the highest Cosine Similarity value. The advantages of the developed DL models are that they can be executed in milliseconds on a PC, can be used for global-scale Earth observations, and can serve as tracers to study how the Earth’s atmosphere moves. The developed models can be used as transfer learning for similar image time-series forecasting models.
T2  - Mathematics
T1  - Deep Learning Model for Global Spatio-Temporal Image Prediction
VL  - 10
IS  - 18
SP  - 3392
DO  - 10.3390/math10183392
ER  - 

@article{
author = "Nikezić, Dušan P. and Ramadani, Uzahir and Radivojević, Dušan and Lazović, Ivan and Mirkov, Nikola S.",
year = "2022",
abstract = "Mathematical methods are the basis of most models that describe the natural phenomena around us. However, the well-known conventional mathematical models for atmospheric modeling have some limitations. Machine learning with Big Data is also based on mathematics but offers a new approach for modeling. There are two methodologies to develop deep learning models for spatio-temporal image prediction. On these bases, two models were built—ConvLSTM and CNN-LSTM—with two types of predictions, i.e., sequence-to-sequence and sequence-to-one, in order to forecast Aerosol Optical Thickness sequences. The input dataset for training was NASA satellite imagery MODAL2_E_AER_OD from Terra/MODIS satellites, which presents global Aerosol Optical Thickness with an 8 day temporal resolution from 2000 to the present. The obtained results show that the ConvLSTM sequence-to-one model had the lowest RMSE error and the highest Cosine Similarity value. The advantages of the developed DL models are that they can be executed in milliseconds on a PC, can be used for global-scale Earth observations, and can serve as tracers to study how the Earth’s atmosphere moves. The developed models can be used as transfer learning for similar image time-series forecasting models.",
journal = "Mathematics",
title = "Deep Learning Model for Global Spatio-Temporal Image Prediction",
volume = "10",
number = "18",
pages = "3392",
doi = "10.3390/math10183392"
}

Nikezić, D. P., Ramadani, U., Radivojević, D., Lazović, I.,& Mirkov, N. S.. (2022). Deep Learning Model for Global Spatio-Temporal Image Prediction. in Mathematics, 10(18), 3392.
https://doi.org/10.3390/math10183392

Nikezić DP, Ramadani U, Radivojević D, Lazović I, Mirkov NS. Deep Learning Model for Global Spatio-Temporal Image Prediction. in Mathematics. 2022;10(18):3392.
doi:10.3390/math10183392 .

Nikezić, Dušan P., Ramadani, Uzahir, Radivojević, Dušan, Lazović, Ivan, Mirkov, Nikola S., "Deep Learning Model for Global Spatio-Temporal Image Prediction" in Mathematics, 10, no. 18 (2022):3392,
https://doi.org/10.3390/math10183392 . .

TY  - JOUR
AU  - Kalderburg, Zoran
AU  - Fabiano, Nicola
AU  - Mirkov, Nikola S.
AU  - Radenović, Stojan
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11718
AB  - The theory of ordered topological vector spaces has been treated in a great number of articles and books. On the other hand, topological vector groups were introduced and studied by D. A. Raikov [On B-complete topological vector groups, Studia Math. 31 (1968), 296-305] and P. S. Kenderov [On topological vector groups, Mat. Sb. 10 (1970), 531-546]. These are vector spaces with a topology in which addition is continuous, but multiplication by scalars is continuous only if the scalar field is taken with the discrete topology. In this paper we introduce ordered topological vector groups and investigate their structure, in particular exploring them in the case when they need not be locally convex.
T2  - Journal of nonlinear and convex analysis
T1  - On ordered topological vector groups - new results
VL  - 23
IS  - 6
SP  - 1231
EP  - 1254
UR  - https://hdl.handle.net/21.15107/rcub_vinar_11718
ER  - 

@article{
author = "Kalderburg, Zoran and Fabiano, Nicola and Mirkov, Nikola S. and Radenović, Stojan",
year = "2022",
abstract = "The theory of ordered topological vector spaces has been treated in a great number of articles and books. On the other hand, topological vector groups were introduced and studied by D. A. Raikov [On B-complete topological vector groups, Studia Math. 31 (1968), 296-305] and P. S. Kenderov [On topological vector groups, Mat. Sb. 10 (1970), 531-546]. These are vector spaces with a topology in which addition is continuous, but multiplication by scalars is continuous only if the scalar field is taken with the discrete topology. In this paper we introduce ordered topological vector groups and investigate their structure, in particular exploring them in the case when they need not be locally convex.",
journal = "Journal of nonlinear and convex analysis",
title = "On ordered topological vector groups - new results",
volume = "23",
number = "6",
pages = "1231-1254",
url = "https://hdl.handle.net/21.15107/rcub_vinar_11718"
}

Kalderburg, Z., Fabiano, N., Mirkov, N. S.,& Radenović, S.. (2022). On ordered topological vector groups - new results. in Journal of nonlinear and convex analysis, 23(6), 1231-1254.
https://hdl.handle.net/21.15107/rcub_vinar_11718

Kalderburg Z, Fabiano N, Mirkov NS, Radenović S. On ordered topological vector groups - new results. in Journal of nonlinear and convex analysis. 2022;23(6):1231-1254.
https://hdl.handle.net/21.15107/rcub_vinar_11718 .

Kalderburg, Zoran, Fabiano, Nicola, Mirkov, Nikola S., Radenović, Stojan, "On ordered topological vector groups - new results" in Journal of nonlinear and convex analysis, 23, no. 6 (2022):1231-1254,
https://hdl.handle.net/21.15107/rcub_vinar_11718 .

TY  - JOUR
AU  - Fabiano, Nicola
AU  - Kadelburg, Zoran
AU  - Mirkov, Nikola S.
AU  - Šešum Čavić, Vesna
AU  - Radenović, Stojan
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/11719
AB  - D. Wardowski proved in 2012 a generalization of Banach Contraction Principle by introducing F-contractions in metric spaces. In the next ten years. a great number of researchers used Wardowski's approach, or some of its modifications, to obtain new fixed point results for single- and multivalued mappings in various kinds of spaces. In this review article. we present a survey of these investigations, including some improvements, in particular concerning conditions imposed on function F entering the contractive condition.
T2  - Contemporary Mathematics
T1  - On F-Contractions: A Survey
VL  - 3
IS  - 3
SP  - 327
EP  - 342
DO  - 10.37256/cm.3320221517
ER  - 

@article{
author = "Fabiano, Nicola and Kadelburg, Zoran and Mirkov, Nikola S. and Šešum Čavić, Vesna and Radenović, Stojan",
year = "2022",
abstract = "D. Wardowski proved in 2012 a generalization of Banach Contraction Principle by introducing F-contractions in metric spaces. In the next ten years. a great number of researchers used Wardowski's approach, or some of its modifications, to obtain new fixed point results for single- and multivalued mappings in various kinds of spaces. In this review article. we present a survey of these investigations, including some improvements, in particular concerning conditions imposed on function F entering the contractive condition.",
journal = "Contemporary Mathematics",
title = "On F-Contractions: A Survey",
volume = "3",
number = "3",
pages = "327-342",
doi = "10.37256/cm.3320221517"
}

Fabiano, N., Kadelburg, Z., Mirkov, N. S., Šešum Čavić, V.,& Radenović, S.. (2022). On F-Contractions: A Survey. in Contemporary Mathematics, 3(3), 327-342.
https://doi.org/10.37256/cm.3320221517

Fabiano N, Kadelburg Z, Mirkov NS, Šešum Čavić V, Radenović S. On F-Contractions: A Survey. in Contemporary Mathematics. 2022;3(3):327-342.
doi:10.37256/cm.3320221517 .

Fabiano, Nicola, Kadelburg, Zoran, Mirkov, Nikola S., Šešum Čavić, Vesna, Radenović, Stojan, "On F-Contractions: A Survey" in Contemporary Mathematics, 3, no. 3 (2022):327-342,
https://doi.org/10.37256/cm.3320221517 . .

TY  - JOUR
AU  - Radenović, Stojan
AU  - Mirkov, Nikola S.
AU  - Paunović, Ljiljana R.
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9800
AB  - Within this manuscript we generalize the two recently obtained results of O. Popescu and G. Stan, regarding the F-contractions in complete, ordinary metric space to 0-complete partial metric space and 0-complete metric-like space. As Popescu and Stan we use less conditions than D. Wardovski did in his paper from 2012, and we introduce, with the help of one of our lemmas, a new method of proving the results in fixed point theory. Requiring that the function F only be strictly increasing, we obtain for consequence new families of contractive conditions that cannot be found in the existing literature. Note that our results generalize and complement many well-known results in the fixed point theory. Also, at the end of the paper, we have stated an application of our theoretical results for solving fractional differential equations. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
T2  - Fractal and Fractional
T1  - Some new results on f-contractions in 0-complete partial metric spaces and 0-complete metric-like spaces
VL  - 5
IS  - 2
DO  - 10.3390/fractalfract5020034
ER  - 

@article{
author = "Radenović, Stojan and Mirkov, Nikola S. and Paunović, Ljiljana R.",
year = "2021",
abstract = "Within this manuscript we generalize the two recently obtained results of O. Popescu and G. Stan, regarding the F-contractions in complete, ordinary metric space to 0-complete partial metric space and 0-complete metric-like space. As Popescu and Stan we use less conditions than D. Wardovski did in his paper from 2012, and we introduce, with the help of one of our lemmas, a new method of proving the results in fixed point theory. Requiring that the function F only be strictly increasing, we obtain for consequence new families of contractive conditions that cannot be found in the existing literature. Note that our results generalize and complement many well-known results in the fixed point theory. Also, at the end of the paper, we have stated an application of our theoretical results for solving fractional differential equations. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.",
journal = "Fractal and Fractional",
title = "Some new results on f-contractions in 0-complete partial metric spaces and 0-complete metric-like spaces",
volume = "5",
number = "2",
doi = "10.3390/fractalfract5020034"
}

Radenović, S., Mirkov, N. S.,& Paunović, L. R.. (2021). Some new results on f-contractions in 0-complete partial metric spaces and 0-complete metric-like spaces. in Fractal and Fractional, 5(2).
https://doi.org/10.3390/fractalfract5020034

Radenović S, Mirkov NS, Paunović LR. Some new results on f-contractions in 0-complete partial metric spaces and 0-complete metric-like spaces. in Fractal and Fractional. 2021;5(2).
doi:10.3390/fractalfract5020034 .

Radenović, Stojan, Mirkov, Nikola S., Paunović, Ljiljana R., "Some new results on f-contractions in 0-complete partial metric spaces and 0-complete metric-like spaces" in Fractal and Fractional, 5, no. 2 (2021),
https://doi.org/10.3390/fractalfract5020034 . .

TY  - CONF
AU  - Tasić, V.
AU  - Božilov, A.
AU  - Lazović, Ivan
AU  - Mirkov, Nikola S.
AU  - Topalović, Dušan
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10993
PB  - Belgrade : University of Belgrade, Vinča Institute of Nuclear Sciences
C3  - WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia
T1  - Civic Air Quality Monitoring As an Alternative and Supplement to the State Air Quality Monitoring Network
SP  - 70
UR  - https://hdl.handle.net/21.15107/rcub_vinar_10993
ER  - 

@conference{
author = "Tasić, V. and Božilov, A. and Lazović, Ivan and Mirkov, Nikola S. and Topalović, Dušan",
year = "2021",
publisher = "Belgrade : University of Belgrade, Vinča Institute of Nuclear Sciences",
journal = "WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia",
title = "Civic Air Quality Monitoring As an Alternative and Supplement to the State Air Quality Monitoring Network",
pages = "70",
url = "https://hdl.handle.net/21.15107/rcub_vinar_10993"
}

Tasić, V., Božilov, A., Lazović, I., Mirkov, N. S.,& Topalović, D.. (2021). Civic Air Quality Monitoring As an Alternative and Supplement to the State Air Quality Monitoring Network. in WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia
Belgrade : University of Belgrade, Vinča Institute of Nuclear Sciences., 70.
https://hdl.handle.net/21.15107/rcub_vinar_10993

Tasić V, Božilov A, Lazović I, Mirkov NS, Topalović D. Civic Air Quality Monitoring As an Alternative and Supplement to the State Air Quality Monitoring Network. in WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia. 2021;:70.
https://hdl.handle.net/21.15107/rcub_vinar_10993 .

Tasić, V., Božilov, A., Lazović, Ivan, Mirkov, Nikola S., Topalović, Dušan, "Civic Air Quality Monitoring As an Alternative and Supplement to the State Air Quality Monitoring Network" in WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia (2021):70,
https://hdl.handle.net/21.15107/rcub_vinar_10993 .

TY  - CONF
AU  - Tasić, V.
AU  - Božilov, A.
AU  - Mišić, N.
AU  - Lazović, Ivan
AU  - Mirkov, Nikola S.
AU  - Topalović, Dušan
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10996
PB  - Belgrade : University of Belgrade, Vinča Institute of Nuclear Sciences
C3  - WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia
T1  - Portable Air Quality Monitor Based on Low-Cost Sensors
SP  - 75
UR  - https://hdl.handle.net/21.15107/rcub_vinar_10996
ER  - 

@conference{
author = "Tasić, V. and Božilov, A. and Mišić, N. and Lazović, Ivan and Mirkov, Nikola S. and Topalović, Dušan",
year = "2021",
publisher = "Belgrade : University of Belgrade, Vinča Institute of Nuclear Sciences",
journal = "WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia",
title = "Portable Air Quality Monitor Based on Low-Cost Sensors",
pages = "75",
url = "https://hdl.handle.net/21.15107/rcub_vinar_10996"
}

Tasić, V., Božilov, A., Mišić, N., Lazović, I., Mirkov, N. S.,& Topalović, D.. (2021). Portable Air Quality Monitor Based on Low-Cost Sensors. in WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia
Belgrade : University of Belgrade, Vinča Institute of Nuclear Sciences., 75.
https://hdl.handle.net/21.15107/rcub_vinar_10996

Tasić V, Božilov A, Mišić N, Lazović I, Mirkov NS, Topalović D. Portable Air Quality Monitor Based on Low-Cost Sensors. in WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia. 2021;:75.
https://hdl.handle.net/21.15107/rcub_vinar_10996 .

Tasić, V., Božilov, A., Mišić, N., Lazović, Ivan, Mirkov, Nikola S., Topalović, Dušan, "Portable Air Quality Monitor Based on Low-Cost Sensors" in WeBIOPATR 2021 : 8th WeBIOPATR Workshop & Conference: Particulate Matter: Research and Management : Abstracts of Keynote Invited Lectures and Contributed Papers; November 29 - December 1, 2021; Belgrade, Serbia (2021):75,
https://hdl.handle.net/21.15107/rcub_vinar_10996 .

TY  - CHAP
AU  - Mirkov, Nikola S.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8523
AB  - This study aims at examining predictive capabilities of a specific global (non-zonal) hybrid RANS/LES turbulent flow simulation strategy in the case of flow over smooth hills. The rationale behind recent popularity of such an approach are constraints on computational resources when one is faced with practical LES for realistic engineering flows. In present approach, which originates from the seminal work of Speziale, simulation is performed on coarser computational meshes then required by LES constraints, where the large part of turbulent kinetic energy is unresolved. A challenge of accurate prediction of wall-bounded flows is approached in hybrid models by blending two approaches (RANS and LES) into a single global model, whereby switching is applied seamlessly based on considerations of turbulent flow and grid scales. The RANS part of the hybrid model is supposed to be active in the vicinity of the wall, and the swift transition to LES model should be performed away from the wall, on a desired distance defined by calibration of switching parameters. In our study we perform transient VLES simulation on a model of smooth hill at laboratory scale, resembling well documented wind tunnel experiment, and study in detail statistical flow properties by comparisons with the experimental results. Special attention is given to hybrid model switching behavior in the said case. The study gives very useful insight into simulation of flows of the industrial and environmental types. © Springer Nature Switzerland AG 2020.
T2  - Lecture Notes in Networks and Systems
T1  - An Application of VLES Turbulent Flow Simulation Methodology to Flow over Smooth Hills
VL  - 90
SP  - 288
EP  - 304
DO  - 10.1007/978-3-030-30853-7_17
ER  - 

@inbook{
author = "Mirkov, Nikola S.",
year = "2020",
abstract = "This study aims at examining predictive capabilities of a specific global (non-zonal) hybrid RANS/LES turbulent flow simulation strategy in the case of flow over smooth hills. The rationale behind recent popularity of such an approach are constraints on computational resources when one is faced with practical LES for realistic engineering flows. In present approach, which originates from the seminal work of Speziale, simulation is performed on coarser computational meshes then required by LES constraints, where the large part of turbulent kinetic energy is unresolved. A challenge of accurate prediction of wall-bounded flows is approached in hybrid models by blending two approaches (RANS and LES) into a single global model, whereby switching is applied seamlessly based on considerations of turbulent flow and grid scales. The RANS part of the hybrid model is supposed to be active in the vicinity of the wall, and the swift transition to LES model should be performed away from the wall, on a desired distance defined by calibration of switching parameters. In our study we perform transient VLES simulation on a model of smooth hill at laboratory scale, resembling well documented wind tunnel experiment, and study in detail statistical flow properties by comparisons with the experimental results. Special attention is given to hybrid model switching behavior in the said case. The study gives very useful insight into simulation of flows of the industrial and environmental types. © Springer Nature Switzerland AG 2020.",
journal = "Lecture Notes in Networks and Systems",
booktitle = "An Application of VLES Turbulent Flow Simulation Methodology to Flow over Smooth Hills",
volume = "90",
pages = "288-304",
doi = "10.1007/978-3-030-30853-7_17"
}

Mirkov, N. S.. (2020). An Application of VLES Turbulent Flow Simulation Methodology to Flow over Smooth Hills. in Lecture Notes in Networks and Systems, 90, 288-304.
https://doi.org/10.1007/978-3-030-30853-7_17

Mirkov NS. An Application of VLES Turbulent Flow Simulation Methodology to Flow over Smooth Hills. in Lecture Notes in Networks and Systems. 2020;90:288-304.
doi:10.1007/978-3-030-30853-7_17 .

Mirkov, Nikola S., "An Application of VLES Turbulent Flow Simulation Methodology to Flow over Smooth Hills" in Lecture Notes in Networks and Systems, 90 (2020):288-304,
https://doi.org/10.1007/978-3-030-30853-7_17 . .

TY  - CONF
AU  - Kastratović, Gordana M.
AU  - Vidanović, Nenad D.
AU  - Grbović, Aleksandar M.
AU  - Mirkov, Nikola S.
AU  - Rašuo, Boško P.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8525
AB  - This paper discusses certain aspects of numerical simulation of crack propagation in wire ropes subjected to axial loading, with the aim to explore and to demonstrate the capacity, performances and difficulties of crack propagation modeling by usage of numerical computational methods in such complex structures. For this purpose, the finite element method (FEM) was used, and 3D numerical analyses were performed in Ansys Workbench software. In order to validate and verify performed numerical modeling, crack growth rate based on calculated stress intensity factors (SIFs) along the crack fronts was obtained for the model for which experimental results could be found in the available literature. Finally, using the advanced modeling techniques, the parametric 3D model of seven-wire strand was analyzed. Conducted analysis showed that FEM could be a powerful tool for fatigue life predictions in order to reduce the need for experiments, which are still the only successful method for fatigue life estimation of wire ropes. © Springer Nature Switzerland AG 2020.
C3  - Computational and Experimental Approaches in Materials Science and Engineering, CNNTech 2019
T1  - Numerical Simulation of Crack Propagation in Seven-Wire Strand
VL  - 90
SP  - 76
EP  - 91
DO  - 10.1007/978-3-030-30853-7_5
ER  - 

@conference{
author = "Kastratović, Gordana M. and Vidanović, Nenad D. and Grbović, Aleksandar M. and Mirkov, Nikola S. and Rašuo, Boško P.",
year = "2020",
abstract = "This paper discusses certain aspects of numerical simulation of crack propagation in wire ropes subjected to axial loading, with the aim to explore and to demonstrate the capacity, performances and difficulties of crack propagation modeling by usage of numerical computational methods in such complex structures. For this purpose, the finite element method (FEM) was used, and 3D numerical analyses were performed in Ansys Workbench software. In order to validate and verify performed numerical modeling, crack growth rate based on calculated stress intensity factors (SIFs) along the crack fronts was obtained for the model for which experimental results could be found in the available literature. Finally, using the advanced modeling techniques, the parametric 3D model of seven-wire strand was analyzed. Conducted analysis showed that FEM could be a powerful tool for fatigue life predictions in order to reduce the need for experiments, which are still the only successful method for fatigue life estimation of wire ropes. © Springer Nature Switzerland AG 2020.",
journal = "Computational and Experimental Approaches in Materials Science and Engineering, CNNTech 2019",
title = "Numerical Simulation of Crack Propagation in Seven-Wire Strand",
volume = "90",
pages = "76-91",
doi = "10.1007/978-3-030-30853-7_5"
}

Kastratović, G. M., Vidanović, N. D., Grbović, A. M., Mirkov, N. S.,& Rašuo, B. P.. (2020). Numerical Simulation of Crack Propagation in Seven-Wire Strand. in Computational and Experimental Approaches in Materials Science and Engineering, CNNTech 2019, 90, 76-91.
https://doi.org/10.1007/978-3-030-30853-7_5

Kastratović GM, Vidanović ND, Grbović AM, Mirkov NS, Rašuo BP. Numerical Simulation of Crack Propagation in Seven-Wire Strand. in Computational and Experimental Approaches in Materials Science and Engineering, CNNTech 2019. 2020;90:76-91.
doi:10.1007/978-3-030-30853-7_5 .

Kastratović, Gordana M., Vidanović, Nenad D., Grbović, Aleksandar M., Mirkov, Nikola S., Rašuo, Boško P., "Numerical Simulation of Crack Propagation in Seven-Wire Strand" in Computational and Experimental Approaches in Materials Science and Engineering, CNNTech 2019, 90 (2020):76-91,
https://doi.org/10.1007/978-3-030-30853-7_5 . .

TY  - CHAP
AU  - Mirkov, Nikola S.
AU  - Vidanović, Nenad D.
AU  - Kastratović, Gordana M.
PY  - 2019
UR  - http://link.springer.com/10.1007/978-3-319-99620-2_11
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8107
AB  - The paper describes development of an open-source library (www.github.com/nikola-m/freeCappuccino) for computational fluid dynamics and in general computational continuum mechanics. The code is based on finite volume method on arbitrary unstructured polyhedral meshes. The interfaces to highly abstract data types such as arbitrary order tensor fields on discretized finite volume domains, and scalar and vector sparse linear systems resulting from finite volume discretization of partial differential equations are provided. Explicit manipulation of tensor fields through high level, highly abstract programming syntax is explained. Also, implicit operation over tensor fields pertinent to discretization of partial differential operators is provided and explained. The library is developed in modern version of Fortran. Code parallelization is achieved through domain decomposition and implemented using MPI and OpenMP. While avoiding the usual class syntax of object-oriented programming, the code has essentially object oriented design. Comparison is made with the well-known OpenFOAM library. The purpose of the ongoing development is providing researchers with a tool for easy transfer of mathematical operations of their physical models into functional and efficient simulation software based on finite volume method. The guiding principle of development is exchange of ideas and reproducibility in computational science in general.
T2  - Lecture Notes in Networks and Systems
T1  - freeCappuccino - An Open Source Software Library for Computational Continuum Mechanics
VL  - 54
SP  - 137
EP  - 147
DO  - 10.1007/978-3-319-99620-2_11
ER  - 

@inbook{
author = "Mirkov, Nikola S. and Vidanović, Nenad D. and Kastratović, Gordana M.",
year = "2019",
abstract = "The paper describes development of an open-source library (www.github.com/nikola-m/freeCappuccino) for computational fluid dynamics and in general computational continuum mechanics. The code is based on finite volume method on arbitrary unstructured polyhedral meshes. The interfaces to highly abstract data types such as arbitrary order tensor fields on discretized finite volume domains, and scalar and vector sparse linear systems resulting from finite volume discretization of partial differential equations are provided. Explicit manipulation of tensor fields through high level, highly abstract programming syntax is explained. Also, implicit operation over tensor fields pertinent to discretization of partial differential operators is provided and explained. The library is developed in modern version of Fortran. Code parallelization is achieved through domain decomposition and implemented using MPI and OpenMP. While avoiding the usual class syntax of object-oriented programming, the code has essentially object oriented design. Comparison is made with the well-known OpenFOAM library. The purpose of the ongoing development is providing researchers with a tool for easy transfer of mathematical operations of their physical models into functional and efficient simulation software based on finite volume method. The guiding principle of development is exchange of ideas and reproducibility in computational science in general.",
journal = "Lecture Notes in Networks and Systems",
booktitle = "freeCappuccino - An Open Source Software Library for Computational Continuum Mechanics",
volume = "54",
pages = "137-147",
doi = "10.1007/978-3-319-99620-2_11"
}

Mirkov, N. S., Vidanović, N. D.,& Kastratović, G. M.. (2019). freeCappuccino - An Open Source Software Library for Computational Continuum Mechanics. in Lecture Notes in Networks and Systems, 54, 137-147.
https://doi.org/10.1007/978-3-319-99620-2_11

Mirkov NS, Vidanović ND, Kastratović GM. freeCappuccino - An Open Source Software Library for Computational Continuum Mechanics. in Lecture Notes in Networks and Systems. 2019;54:137-147.
doi:10.1007/978-3-319-99620-2_11 .

Mirkov, Nikola S., Vidanović, Nenad D., Kastratović, Gordana M., "freeCappuccino - An Open Source Software Library for Computational Continuum Mechanics" in Lecture Notes in Networks and Systems, 54 (2019):137-147,
https://doi.org/10.1007/978-3-319-99620-2_11 . .

TY  - JOUR
AU  - Mirkov, Nikola S.
AU  - Stevanović, Žarko M.
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1146
AB  - In this paper we validate an improved finite volume approximation of Reynolds averaged Navier-Stokes equations for simulation of wind flows in body-fitted grids generated by algebraic extrusion from digital terrain elevation data, proposed in Mirkov et. al. [1]. The approach is based on second-order accurate finite volume method with collocated variable arrangement and pressure-velocity coupling trough SIMPLE algorithm. The main objective is the attenuation of spurious pressure field oscillations in regions with discontinuity in grid line slopes, as encountered in grids representing highly non-uniform terrains. Moreover, the approach relaxes the need for grid generation based on elliptic partial differential equation or grid smoothing by applying fixed point iterations (i. e. Gauss-Seidel) to initial grid node positions resulting from algebraic grid generators. Drawbacks of previous approaches which ignored treatment of finite volume grid cell cases with intersection point offset in non-orthogonality corrections are removed. Application to real-life wind farm project at Dobric (Svrljig, Serbia) is used to assess the effectiveness of the method. The results validate the view in which accurate discretization of governing equations play more important role than the choice of turbulence modeling closures.
T2  - Thermal Science
T1  - New non-orthogonality treatment for atmospheric boundary layer flow simulation above highly non-uniform terrains
VL  - 20
SP  - S223
EP  - S233
DO  - 10.2298/TSCI151025197M
ER  - 

@article{
author = "Mirkov, Nikola S. and Stevanović, Žarko M.",
year = "2016",
abstract = "In this paper we validate an improved finite volume approximation of Reynolds averaged Navier-Stokes equations for simulation of wind flows in body-fitted grids generated by algebraic extrusion from digital terrain elevation data, proposed in Mirkov et. al. [1]. The approach is based on second-order accurate finite volume method with collocated variable arrangement and pressure-velocity coupling trough SIMPLE algorithm. The main objective is the attenuation of spurious pressure field oscillations in regions with discontinuity in grid line slopes, as encountered in grids representing highly non-uniform terrains. Moreover, the approach relaxes the need for grid generation based on elliptic partial differential equation or grid smoothing by applying fixed point iterations (i. e. Gauss-Seidel) to initial grid node positions resulting from algebraic grid generators. Drawbacks of previous approaches which ignored treatment of finite volume grid cell cases with intersection point offset in non-orthogonality corrections are removed. Application to real-life wind farm project at Dobric (Svrljig, Serbia) is used to assess the effectiveness of the method. The results validate the view in which accurate discretization of governing equations play more important role than the choice of turbulence modeling closures.",
journal = "Thermal Science",
title = "New non-orthogonality treatment for atmospheric boundary layer flow simulation above highly non-uniform terrains",
volume = "20",
pages = "S223-S233",
doi = "10.2298/TSCI151025197M"
}

Mirkov, N. S.,& Stevanović, Ž. M.. (2016). New non-orthogonality treatment for atmospheric boundary layer flow simulation above highly non-uniform terrains. in Thermal Science, 20, S223-S233.
https://doi.org/10.2298/TSCI151025197M

Mirkov NS, Stevanović ŽM. New non-orthogonality treatment for atmospheric boundary layer flow simulation above highly non-uniform terrains. in Thermal Science. 2016;20:S223-S233.
doi:10.2298/TSCI151025197M .

Mirkov, Nikola S., Stevanović, Žarko M., "New non-orthogonality treatment for atmospheric boundary layer flow simulation above highly non-uniform terrains" in Thermal Science, 20 (2016):S223-S233,
https://doi.org/10.2298/TSCI151025197M . .

TY  - JOUR
AU  - Mirkov, Nikola S.
AU  - Rasuo, Bosko
AU  - Kenjeres, Sasa
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/268
AB  - This article presents a new and substantially improved finite volume procedure for simulation of incompressible flows on non-orthogonal grids. Cell-centered least-squares gradients are obtained in a robust and highly accurate way. A new discretization of the diffusive terms is employed, which is based on extension of the original cell-face gradient interpolation and is more suitable for complex grid distortions. A flexible flux-limited interpolation of dependent variables on distorted computational grids is introduced. An efficient preconditioner for Krylov method solution of linear systems is proposed, which substantially improves the solution of Poisson equation for pressure correction. The pressure-correction algorithm is adapted for efficient convergence on highly complex grids using a sequence of non-orthogonal corrector solutions and its effect on iteration convergence is analyzed. The non-orthogonalities treated by current procedure are more accustomed to numerical grids generated from a real complex terrain elevation data. The main focus is on the simulation of atmospheric micro-scale flows pertinent to wind energy application.
T2  - Journal of Computational Physics
T1  - On the improved finite volume procedure for simulation of turbulent flows over real complex terrains
VL  - 287
SP  - 18
EP  - 45
DO  - 10.1016/j.jcp.2015.02.001
ER  - 

@article{
author = "Mirkov, Nikola S. and Rasuo, Bosko and Kenjeres, Sasa",
year = "2015",
abstract = "This article presents a new and substantially improved finite volume procedure for simulation of incompressible flows on non-orthogonal grids. Cell-centered least-squares gradients are obtained in a robust and highly accurate way. A new discretization of the diffusive terms is employed, which is based on extension of the original cell-face gradient interpolation and is more suitable for complex grid distortions. A flexible flux-limited interpolation of dependent variables on distorted computational grids is introduced. An efficient preconditioner for Krylov method solution of linear systems is proposed, which substantially improves the solution of Poisson equation for pressure correction. The pressure-correction algorithm is adapted for efficient convergence on highly complex grids using a sequence of non-orthogonal corrector solutions and its effect on iteration convergence is analyzed. The non-orthogonalities treated by current procedure are more accustomed to numerical grids generated from a real complex terrain elevation data. The main focus is on the simulation of atmospheric micro-scale flows pertinent to wind energy application.",
journal = "Journal of Computational Physics",
title = "On the improved finite volume procedure for simulation of turbulent flows over real complex terrains",
volume = "287",
pages = "18-45",
doi = "10.1016/j.jcp.2015.02.001"
}

Mirkov, N. S., Rasuo, B.,& Kenjeres, S.. (2015). On the improved finite volume procedure for simulation of turbulent flows over real complex terrains. in Journal of Computational Physics, 287, 18-45.
https://doi.org/10.1016/j.jcp.2015.02.001

Mirkov NS, Rasuo B, Kenjeres S. On the improved finite volume procedure for simulation of turbulent flows over real complex terrains. in Journal of Computational Physics. 2015;287:18-45.
doi:10.1016/j.jcp.2015.02.001 .

Mirkov, Nikola S., Rasuo, Bosko, Kenjeres, Sasa, "On the improved finite volume procedure for simulation of turbulent flows over real complex terrains" in Journal of Computational Physics, 287 (2015):18-45,
https://doi.org/10.1016/j.jcp.2015.02.001 . .