Nikolina Frid

Dr. Nikolina Frid

University of Zagreb, Faculty of Electrical Engineering and Computing, Zagreb, Zagreb, Grad, Croatia
orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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19 October 2021 in Sensors
Verified
Journal Article
Open access
PDF file
ISIgor Stancin
Igor Stancin
NFNikolina Frid
Nikolina Frid
MCMario Cifrek
Mario Cifrek
AJAlan Jovic
Alan Jovic
Drowsiness is a risk to human lives in many occupations and activities where full awareness is essential for the safe operation of systems and vehicles, such as driving a car or flying an airplane. Although it is one of the main causes of many road accidents, there is still no reliable definition of drowsiness or a system to reliably detect it. Many researchers have observed correlations between frequency-domain features of the EEG signal and drowsiness, such as an increase in the spectral power of the theta band or a decrease in the spectral power of the beta band. In addition, features calculated as ratio indices between these frequency-domain features show further improvements in detecting drowsiness compared to frequency-domain features alone. This work aims to develop novel multichannel ratio indices that take advantage of the diversity of frequency-domain features from different brain regions. In contrast to the state-of-the-art, we use an evolutionary metaheuristic algorithm to find the nearly optimal set of features and channels from which the indices are calculated. Our results show that drowsiness is best described by the powers in delta and alpha bands. Compared to seven existing single-channel ratio indices, our two novel six-channel indices show improvements in (1) statistically significant differences observed between wakefulness and drowsiness segments, (2) precision of drowsiness detection and classification accuracy of the XGBoost algorithm and (3) model performance by saving time and memory during classification. Our work suggests that a more precise definition of drowsiness is needed, and that accurate early detection of drowsiness should be based on multichannel frequency-domain features.


1 April 2014
Verified
Conference Paper
Closed access
MZMartin Zagar
Martin Zagar
NFNikolina Frid
Nikolina Frid
JKJosip Knezovic
Josip Knezovic
DHDaniel Hofman
Daniel Hofman
MKMario Kovac
Mario Kovac
HMHrvoje Mlinaric
Hrvoje Mlinaric
To overcome a complex and multidisciplinary approach which includes understanding of various systems based on different technologies and system solution optimizations in engineering education for embedded systems at university level and provide a complex and multidisciplinary approach, the first cycle of the design of a unified, multiple-target platform that will enable integrated approach to computer engineering and embedded systems learning has been finished so far. This work shows results of current research, preliminary conclusions and future focuses.

7 April 2022 in SoftwareX
Verified
Journal Article
Open access
KJKrešimir Jozić
Krešimir Jozić
NFNikolina Frid
Nikolina Frid
AJAlan Jovic
Alan Jovic
ŽMŽeljka Mihajlović
Željka Mihajlović

2 January 2019 in Automatika
Verified
Journal Article
Open access
NFNikolina Frid
Nikolina Frid
DIDanko Ivošević
Danko Ivošević
VSVlado Sruk
Vlado Sruk
Early application timing estimation is essential in decision making during design space exploration of heterogeneous embedded systems in terms of hardware platform dimensioning and component selection. The decisions which have the impact on project duration and cost must be made before a platform prototype is available and software code is ready to be linked and thus timing estimation must be done using high-level models and simulators. Because of the ever increasing need to shorten the time to market, reducing the amount of time required to obtain the results is as important as achieving high estimation accuracy. In this paper, we propose a novel approach to source-level timing estimation with the aim to close the speed-accuracy gap by raising the level of abstraction and improving result reusability. We introduce a concept – elementary operations as distinct parts of source code which enable capturing platform behaviour without having the exact model of the processor pipeline, cache etc. We also present a timing estimation method which relies on elementary operations to craft hardware profiling benchmark and to build application and platform profiles. Experiments show an average estimation error of 5%, with maximum below 16%.

5 December 2024 in Complex & Intelligent Systems
Verified
Journal Article
Open access
PDF file
NFNikolina Frid
Nikolina Frid
MƉMarko Ɖurasević
Marko Ɖurasević
FGFrancisco Javier Gil-Gala
Francisco Javier Gil-Gala
The concept of green scheduling, which deals with the environmental impact of the scheduling process, is becoming increasingly important due to growing environmental concerns. Most green scheduling problem variants focus on modelling the energy consumption during the execution of the schedule. However, the dynamic unrelated machines environment is rarely considered, mainly because it is difficult to manually design simple heuristics, called dispatching rules (DRs), which are suitable for solving dynamic, non-standard scheduling problems. Using hyperheuristics, especially genetic programming (GP), alleviates the problem since it enables the automatic design of new DRs. In this study, we apply GP to automatically design DRs for solving the green scheduling problem in the unrelated machines environment under dynamic conditions. The total energy consumed during the system execution is optimised along with two standard scheduling criteria. The three most commonly investigated green scheduling problem variants from the literature are selected, and GP is adapted to generate appropriate DRs for each. The experiments show that GP-generated DRs efficiently solve the problem under dynamic conditions, providing a trade-off between optimising standard and energy-related criteria.