Bratislav Predic

Bratislav Predic

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 November 2023 in Complex & Intelligent Systems
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BPBratislav Predic
Bratislav Predic
Luka Dragoljub JovanovicLuka Dragoljub Jovanovic
Luka Dragoljub Jovanovic
Vladimir SimicVladimir Simic
Vladimir Simic
NEBOJSA BACANINNEBOJSA BACANIN
NEBOJSA BACANIN
Miodrag ZivkovicMiodrag Zivkovic
Miodrag Zivkovic
MDMiloš Dobrojević
Miloš Dobrojević
Recent improvements in networking technologies have led to a significant shift towards distributed cloud-based services. However, adequate management of computation resources by providers is vital to maintain the costs of operations and quality of services. A robust system is needed to forecast demand and prevent excessive resource allocations. Extensive literature review suggests that the potential of recurrent neural networks with attention mechanisms is not sufficiently explored and applied to cloud computing. To address this gap, this work proposes a methodology for forecasting load of cloud resources based on recurrent neural networks with and without attention layers. Utilized deep learning models are further optimized through hyperparameter tuning using a modified particle swarm optimization metaheuristic, which is also introduced in this work. To help models deal with complex non-stationary data sequences, the variational mode decomposition for decomposing complex series has also been utilized. The performance of this approach is compared to several state-of-the-art algorithms on a real-world cloud-load dataset. Captured performance metrics ( $$R^2$$ R 2 , mean square error, root mean square error, and index of agreement) strongly indicate that the proposed method has great potential for accurately forecasting cloud load. Further, models optimized by the introduced metaheuristic outperformed competing approaches, which was confirmed by conducted statistical validation. In addition, the best-performing forecasting model has been subjected to SHapley Additive exPlanations analysis to determine the impact each feature has on model forecasts, which could potentially be a very useful tool for cloud providers when making decisions.

30 July 2020 in Symmetry
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Darjan KarabasevicDarjan Karabasevic
Darjan Karabasevic
Dragisa StanujkicDragisa Stanujkic
Dragisa Stanujkic
Edmundas Kazimieras ZavadskasEdmundas Kazimieras Zavadskas
Edmundas Kazimieras Zavadskas
Predrag S. StanimirovicPredrag S. Stanimirovic
Predrag S. Stanimirovic
Gabrijela PopovicGabrijela Popovic
Gabrijela Popovic
AUAlptekin Ulutaş
Alptekin Ulutaş
Neutrosophic sets have been recognized as an effective approach in solving complex decision-making (DM) problems, mainly when such problems are related to uncertainties, as published in numerous articles thus far. The use of the three membership functions that can be used to express accuracy, inaccuracy, and indeterminacy during the evaluation of alternatives in multiple-criteria DM can be said to be a significant advantage of these sets. By utilizing these membership functions, neutrosophic sets provide an efficient and flexible approach to the evaluation of alternatives, even if DM problems are related to uncertainty and predictions. On the other hand, the TOPSIS method is a prominent multiple-criteria decision-making method used so far to solve numerous decision-making problems, and many extensions of the TOPSIS method are proposed to enable the use of different types of fuzzy as well as neutrosophic sets. Therefore, a novel extension of the TOPSIS method adapted for the use of single-valued neutrosophic sets was considered in this paper.

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Aleksandar MilosavljevićAleksandar Milosavljević
Aleksandar Milosavljević
DRDejan Rančić
Dejan Rančić
ADAleksandar Dimitrijevic
Aleksandar Dimitrijevic
BPBratislav Predic
Bratislav Predic
VMVladan Mihajlović
Vladan Mihajlović
The integration of a surveillance camera video with a three-dimensional (3D) geographic information system (GIS) requires the georeferencing of that video. Since a video consists of separate frames, each frame must be georeferenced. To georeference a video frame, we rely on the information about the camera view at the moment that the frame was captured. A camera view in 3D space is completely determined by the camera position, orientation, and field-of-view. Since the accurate measuring of these parameters can be extremely difficult, in this paper we propose a method for their estimation based on matching video frame coordinates of certain point features with their 3D geographic locations. To obtain these coordinates, we rely on high-resolution orthophotos and digital elevation models (DEM) of the area of interest. Once an adequate number of points are matched, Levenberg–Marquardt iterative optimization is applied to find the most suitable video frame georeference, i.e., position and orientation of the camera.

11 May 2024 in Science of The Total Environment
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FSFaculty of Science, University of Kragujevac Simović
Faculty of Science, University of Kragujevac Simović
Aleksandar MilosavljevićAleksandar Milosavljević
Aleksandar Milosavljević
KSKatarina Zoran Stojanović
Katarina Zoran Stojanović
MRMilena Radenković
Milena Radenković
Dimitrija Savić-ZdrakovićDimitrija Savić-Zdraković
Dimitrija Savić-Zdraković
Djuradj MiloševićDjuradj Milošević
Djuradj Milošević

13 May 2022 in Axioms
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BPBratislav Predic
Bratislav Predic
UVUroš Vukić
Uroš Vukić
Muzafer SaračevićMuzafer Saračević
Muzafer Saračević
Darjan KarabasevicDarjan Karabasevic
Darjan Karabasevic
Dragisa StanujkicDragisa Stanujkic
Dragisa Stanujkic
In the paper, the possibility of combining deep neural network (DNN) model compression methods to achieve better compression results was considered. To compare the advantages and disadvantages of each method, all methods were applied to the ResNet18 model for pretraining to the NCT-CRC-HE-100K dataset while using CRC-VAL-HE-7K as the validation dataset. In the proposed method, quantization, pruning, weight clustering, QAT (quantization-aware training), preserve cluster QAT (hereinafter PCQAT), and distillation were performed for the compression of ResNet18. The final evaluation of the obtained models was carried out on a Raspberry Pi 4 device using the validation dataset. The greatest model compression result on the disk was achieved by applying the PCQAT method, whose application led to a reduction in size of the initial model by as much as 45 times, whereas the greatest model acceleration result was achieved via distillation on the MobileNetV2 model. All methods led to the compression of the initial size of the model, with a slight loss in the model accuracy or an increase in the model accuracy in the case of QAT and weight clustering. INT8 quantization and knowledge distillation also led to a significant decrease in the model execution time.

27 October 2024 in Electronics
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AŠAleksandar Šijan
Aleksandar Šijan
DVDejan Viduka
Dejan Viduka
LILuka Ilić
Luka Ilić
BPBratislav Predic
Bratislav Predic
Darjan KarabasevicDarjan Karabasevic
Darjan Karabasevic
This paper presents a comprehensive model for cyber security risk assessment using the PIPRECIA-S method within decision theory, which enables organizations to systematically identify, assess and prioritize key cyber threats. The study focuses on the evaluation of malware, ransomware, phishing and DDoS attacks, using criteria such as severity of impact, financial losses, ease of detection and prevention, impact on reputation and system recovery. This approach facilitates decision making, as it enables the flexible adaptation of the risk assessment to the specific needs of an organization. The PIPRECIA-S model has proven to be useful for identifying the most critical threats, with a special emphasis on ransomware and DDoS attacks, which represent the most significant risks to businesses. This model provides a framework for making informed and strategic decisions to reduce risk and strengthen cyber security, which are critical in a digital environment where threats become more and more sophisticated.