Branislav Pejak

Mr. Branislav Pejak

BioSense Institute, Novi Sad, Serbia
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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22 February 2021 in Journal of Cloud Computing
Verified
Journal Article
Open access
PDF file
NZNaweiluo Zhou
Naweiluo Zhou
YGYiannis Georgiou
Yiannis Georgiou
MPMarcin Pospieszny
Marcin Pospieszny
LZLi Zhong
Li Zhong
HZHuan Zhou
Huan Zhou
DHDennis Hoppe
Dennis Hoppe
Containerisation demonstrates its efficiency in application deployment in Cloud Computing. Containers can encapsulate complex programs with their dependencies in isolated environments making applications more portable, hence are being adopted in High Performance Computing (HPC) clusters.Singularity, initially designed for HPC systems, has become theirde factostandard container runtime. Nevertheless, conventional HPC workload managers lack micro-service support and deeply-integrated container management, as opposed to container orchestrators. We introduce a Torque-Operator which serves as a bridge between HPC workload manager (TORQUE) and container orchestrator (Kubernetes). We propose a hybrid architecture that integrates HPC and Cloud clusters seamlessly with little interference to HPC systems where container orchestration is performed on two levels.

6 March 2023 in Drones
Verified
Journal Article
Open access
PDF file
KRKristina Rančić
Kristina Rančić
BBBosko Blagojevic
Bosko Blagojevic
Atila BezdanAtila Bezdan
Atila Bezdan
BIBojana Ivošević
Bojana Ivošević
BTBojan Tubić
Bojan Tubić
OMOskar Marko
Oskar Marko
In the last decade, small unmanned aerial vehicles (UAVs/drones) have become increasingly popular in the airborne observation of large areas for many purposes, such as the monitoring of agricultural areas, the tracking of wild animals in their natural habitats, and the counting of livestock. Coupled with deep learning, they allow for automatic image processing and recognition. The aim of this work was to detect and count the deer population in northwestern Serbia from such images using deep neural networks, a tedious process that otherwise requires a lot of time and effort. In this paper, we present and compare the performance of several state-of-the-art network architectures, trained on a manually annotated set of images, and use it to predict the presence of objects in the rest of the dataset. We implemented three versions of the You Only Look Once (YOLO) architecture and a Single Shot Multibox Detector (SSD) to detect deer in a dense forest environment and measured their performance based on mean average precision (mAP), precision, recall, and F1 score. Moreover, we also evaluated the models based on their real-time performance. The results showed that the selected models were able to detect deer with a mean average precision of up to 70.45% and a confidence score of up to a 99%. The highest precision was achieved by the fourth version of YOLO with 86%, as well as the highest recall value of 75%. Its compressed version achieved slightly lower results, with 83% mAP in its best case, but it demonstrated four times better real-time performance. The counting function was applied on the best-performing models, providing us with the exact distribution of deer over all images. Yolov4 obtained an error of 8.3% in counting, while Yolov4-tiny mistook 12 deer, which accounted for an error of 7.1%.

7 May 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Branislav PejakBranislav Pejak
Branislav Pejak
PLPredrag Lugonja
Predrag Lugonja
AAAleksandar Antić
Aleksandar Antić
Marko Neven PanićMarko Neven Panić
Marko Neven Panić
MPMiloš Pandžić
Miloš Pandžić
VCVladimir Crnojević
Vladimir Crnojević
Agriculture is the backbone and the main sector of the industry for many countries in the world. Assessing crop yields is key to optimising on-field decisions and defining sustainable agricultural strategies. Remote sensing applications have greatly enhanced our ability to monitor and manage farming operation. The main objective of this research was to evaluate machine learning system for within-field soya yield prediction trained on Sentinel-2 multispectral images and soil parameters. Multispectral images used in the study came from ESA’s Sentinel-2 satellites. A total of 3 cloud-free Sentinel-2 multispectral images per year from specific periods of vegetation were used to obtain the time-series necessary for crop yield prediction. Yield monitor data were collected in three crop seasons (2018, 2019 and 2020) from a number of farms located in Upper Austria. The ground-truth database consisted of information about the location of the fields and crop yield monitor data on 411 ha of farmland. A novel method, namely the Polygon-Pixel Interpolation, for optimal fitting yield monitor data with satellite images is introduced. Several machine learning algorithms, such as Multiple Linear Regression, Support Vector Machine, eXtreme Gradient Boosting, Stochastic Gradient Descent and Random Forest, were compared for their performance in soya yield prediction. Among the tested machine learning algorithms, Stochastic Gradient Descent regression model performed better than the others, with a mean absolute error of 4.36 kg/pixel (0.436 t/ha) and a correlation coefficient of 0.83%.

10 November 2022 in Atmosphere
Verified
Journal Article
Open access
PDF file
GMGordan Mimić
Gordan Mimić
BZBranislav Zivaljevic
Branislav Zivaljevic
Dragana BlagojevićDragana Blagojević
Dragana Blagojević
Branislav PejakBranislav Pejak
Branislav Pejak
SBSanja Brdar
Sanja Brdar
The drought in Serbia in the summer of 2017 heavily affected agricultural production, decreasing yields of maize, sunflower, soybean, and sugar beet. Monitoring moisture levels in crops can provide timely information about potential risk within a growing season, thus helping to create an early warning system for various stakeholders. The purpose of this study was to quantify the level of moisture stress in crops during summer and the consequences that it can have on yields. For that, maize and sunflower yield data provided by an agricultural company were used at specific parcels in the Backa region of Vojvodina province (Serbia) for 2017, 2018, 2019, and 2020. The crop moisture level was estimated at each parcel by calculating the normalized difference moisture index (NDMI) from Sentinel-2 data during the summer months (June–July–August). Based on the average NDMI value in July, the new crop moisture stress (CMS) index was introduced. The results showed that the CMS values at a specific parcel could be used for within-season estimation of maize and sunflower yield and the assessment of drought effects. The CMS index was tested for the current growing season of 2022 as an early warning system for yield reduction, demonstrating the potential to be included in a platform for digital agriculture, such as AgroSens, which is operational in Serbia.

2 October 2023 in GIScience & Remote Sensing
Verified
Journal Article
Open access
MRMirjana Radulović
Mirjana Radulović
SBSanja Brdar
Sanja Brdar
Branislav PejakBranislav Pejak
Branislav Pejak
PLPredrag Lugonja
Predrag Lugonja
IAIoannis Athanasiadis
Ioannis Athanasiadis
VCVladimir Crnojević
Vladimir Crnojević

24 July 2025 in European Journal of Remote Sensing
Verified
Journal Article
Open access
MMMiljana Marković
Miljana Marković
PLPredrag Lugonja
Predrag Lugonja
SBSanja Brdar
Sanja Brdar
IAIoannis Athanasiadis
Ioannis Athanasiadis
MRMirjana Radulović
Mirjana Radulović
VCVladimir Crnojević
Vladimir Crnojević