Akos Zarandy

Prof. Akos Zarandy


Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

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

Representative Publications

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1 January 1999 in International Journal of Circuit Theory and Applications
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Journal Article
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AZAkos Zarandy
Akos Zarandy

5 August 2021 in Applied Sciences
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Journal Article
Open access
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ÁNÁdám Nagy
Ádám Nagy
PFPéter Földesy
Péter Földesy
IJImre Jánoki
Imre Jánoki
DTDániel Terbe
Dániel Terbe
MSMáté Siket
Máté Siket
AZAkos Zarandy
Akos Zarandy
Non-contact visual monitoring of vital signs in neonatology has been demonstrated by several recent studies in ideal scenarios where the baby is calm and there is no medical or parental intervention. Similar to contact monitoring methods (e.g., ECG, pulse oximeter) the camera-based solutions suffer from motion artifacts. Therefore, during care and the infants’ active periods, calculated values typically differ largely from the real ones. In this way, our main contribution to existing remote camera-based techniques is to detect and classify such situations with a high level of confidence. Our algorithms can not only evaluate quiet periods, but can also provide continuous monitoring. Altogether, our proposed algorithms can measure pulse rate, breathing rate, and to recognize situations such as medical intervention or very active subjects using only a single camera, while the system does not exceed the computational capabilities of average CPU-GPU-based hardware. The performance of the algorithms was evaluated on our database collected at the Ist Dept. of Neonatology of Pediatrics, Dept of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary.

26 June 2006 in International Journal of Circuit Theory and Applications
Verified
Journal Article
Closed access
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PFPéter Földesy
Péter Földesy
AZAkos Zarandy
Akos Zarandy
CRCsaba Rekeczky
Csaba Rekeczky
TRTamás Roska
Tamás Roska

17 October 2011 in International Journal of Circuit Theory and Applications
Verified
Journal Article
Closed access
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AZAkos Zarandy
Akos Zarandy
CRCsaba Rekeczky
Csaba Rekeczky

31 October 2022 in Sensors
Verified
Journal Article
Open access
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DTDániel Terbe
Dániel Terbe
LOLászló Orzó
László Orzó
AZAkos Zarandy
Akos Zarandy
A hologram, measured by using appropriate coherent illumination, records all substantial volumetric information of the measured sample. It is encoded in its interference patterns and, from these, the image of the sample objects can be reconstructed in different depths by using standard techniques of digital holography. We claim that a 2D convolutional network (CNN) cannot be efficient in decoding this volumetric information spread across the whole image as it inherently operates on local spatial features. Therefore, we propose a method, where we extract the volumetric information of the hologram by mapping it to a volume—using a standard wavefield propagation algorithm—and then feed it to a 3D-CNN-based architecture. We apply this method to a challenging real-life classification problem and compare its performance with an equivalent 2D-CNN counterpart. Furthermore, we inspect the robustness of the methods to slightly defocused inputs and find that the 3D method is inherently more robust in such cases. Additionally, we introduce a hologram-specific augmentation technique, called hologram defocus augmentation, that improves the performance of both methods for slightly defocused inputs. The proposed 3D-model outperforms the standard 2D method in classification accuracy both for in-focus and defocused input samples. Our results confirm and support our fundamental hypothesis that a 2D-CNN-based architecture is limited in the extraction of volumetric information globally encoded in the reconstructed hologram image.

9 March 2023 in Remote Sensing
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Journal Article
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PBPeter Bauer
Peter Bauer
Antal HibaAntal Hiba
Antal Hiba
MNMihály Nagy
Mihály Nagy
ESErnő Simonyi
Ernő Simonyi
GKGergely István Kuna
Gergely István Kuna
AZAkos Zarandy
Akos Zarandy
Forerunner UAV refers to an unmanned aerial vehicle equipped with a downward-looking camera flying in front of the advancing emergency ground vehicles (EGV) to notify the driver about the hidden dangers (e.g., other vehicles). A feasibility demonstration in an urban environment having a multicopter as the forerunner UAV and two cars as the emergency and dangerous ground vehicles was done in ZalaZONE Proving Ground, Hungary. After the description of system hardware and software components, test scenarios, object detection and tracking, the main contribution of the paper is the development and evaluation of encounter risk decision methods. First, the basic collision risk evaluation applied in the demonstration is summarized, then the detailed development of an improved method is presented. It starts with the comparison of different velocity and acceleration estimation methods. Then, vehicle motion prediction is conducted, considering estimated data and its uncertainty. The prediction time horizon is determined based on actual EGV speed and so braking time. If the predicted trajectories intersect, then the EGV driver is notified about the danger. Some special relations between EGV and the other vehicle are also handled. Tuning and comparison of basic and improved methods is done based on real data from the demonstration. The improved method can notify the driver longer, identify special relations between the vehicles and it is adaptive considering actual EGV speed and EGV braking characteristics; therefore, it is selected for future application.