Hazal Su Bıçakcı Yeşilkaya

Dr. Hazal Su Bıçakcı Yeşilkaya

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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16 December 2022 in IET Biometrics
Verified
Journal Article
Open access
HYHazal Su Bıçakcı Yeşilkaya
Hazal Su Bıçakcı Yeşilkaya
MSMarco Santopietro
Marco Santopietro
RGRichard Guest
Richard Guest
Activity classification and biometric authentication have become synonymous with wearable technologies such as smartwatches and trackers. Although great efforts have been made to develop electrocardiogram (ECG)‐based biometric verification and identification modalities using data from these devices, in this paper, we explore the use of adaptive techniques based on prior activity classification in an attempt to enhance biometric performance. In doing so, we also compare two waveform similarity distances to provide features for classification. Two public datasets which were collected from medical and wearable devices provide a cross‐device comparison. Our results show that our method is able to be used for both wearable and medical devices in activity classification and biometric verification cases. This study is the first study which uses only ECG signals for both activity classification and biometric verification purposes.

11 October 2021
Verified
Conference Paper
Closed access
HYHazal Su Bıçakcı Yeşilkaya
Hazal Su Bıçakcı Yeşilkaya
MSMarco Santopietro
Marco Santopietro
MBMatthew Boakes
Matthew Boakes
RGRichard Guest
Richard Guest
Biometric authentication is nowadays widely used in a multitude of scenarios. Several studies have been conducted on electrocardiogram (ECG) for subject identification or verification among the various modalities. However, none have considered a typical implementation with a mobile device and the necessity for a fast-training model with limited recording time for the signal. This study tackles this issue by exploring various classification models on short recordings and evaluating the performance varying the sample length and the training set size. We run our tests on two public datasets collected from wearable and medical devices and propose a pipeline for ECG authentication with limited data required for competitive usage across applications.

20 August 2025 in Drones
Verified
Journal Article
Open access
PDF file
MÖMete Özbaltan
Mete Özbaltan
SÇserkan çaşka
serkan çaşka
CŞCihat ŞEKER
Cihat ŞEKER
MYMerve YILDIRIM
Merve YILDIRIM
HYHazal Su Bıçakcı Yeşilkaya
Hazal Su Bıçakcı Yeşilkaya
Murat DemirMurat Demir
Murat Demir
We propose a novel systematic approach for the deployment optimization of unmanned aerial vehicles (UAVs). In this context, this study focuses on enhancing the coverage of UAV-mounted 6G mobile base stations. The number and placement optimization of UAV-mounted 6G mobile base stations, deployed to support terrestrial base stations during periods of increased population density in a given area, are addressed using a symbolic limited optimal discrete controller synthesis technique. Within the scope of this study, the UAVs’ altitude and attitude behaviors are optimized to ensure the most efficient trajectory toward the designated base station coordinates. Additionally, at their new locations, these behaviors are adjusted to facilitate accurate coverage estimation from the base stations they serve. In the deployment optimization of UAVs, the placement of base stations is determined using received signal strength data obtained through the ray-tracing-based channel modeling technique. The channel model considered critical parameters such as path loss, received power, weather loss, and foliage loss. Final average path loss values of 102.3 dB, 111.7 dB, and 127.4 dB were obtained at the carrier frequencies of 7 GHz, 26 GHz, and 140 GHz, respectively. These findings were confirmed with MATLAB-based ray tracing simulations. Our proposed approach is validated through experimental evaluations, demonstrating superior performance compared to existing methods reported in the literature.

24 May 2025 in Biomimetics
Verified
Journal Article
Open access
PDF file
MÖMete Özbaltan
Mete Özbaltan
NÖNihan Özbaltan
Nihan Özbaltan
HYHazal Su Bıçakcı Yeşilkaya
Hazal Su Bıçakcı Yeşilkaya
Murat DemirMurat Demir
Murat Demir
CŞCihat ŞEKER
Cihat ŞEKER
MYMerve YILDIRIM
Merve YILDIRIM
Task scheduling for multiple humanoid robot manipulators in industrial and collaborative settings remains a significant challenge due to the complexity of coordination, resource sharing, and real-time decision-making. In this study, we propose a framework for modeling task scheduling for multiple humanoid robot manipulators by using the symbolic discrete controller synthesis technique. We encode the task scheduling problem as discrete events using parallel synchronous dataflow equations and apply our synthesis algorithms to manage the task scheduling of multiple humanoid robots via the resulting controller. The control objectives encompass the fundamental behaviors of the system, strict rules, and mutual exclusions over shared resources, categorized as the safety property, whereas the optimization objectives are directed toward maximizing the throughput of robot-processed products with optimal efficiency. The humanoid robots considered in this study consist of two pairs of six-degree-of-freedom (6-DOF) robot manipulators, and the inverse kinematics problem of the 6-DOF arms is addressed using metaheuristic approaches inspired by biomimetic principles. Our approach is experimentally validated, and the results demonstrate high accuracy and performance compared to other approaches reported in the literature. Our approach achieved an average efficiency improvement of 40% in 70-robot systems, 20% in 30-robot systems, and 10% in 10-robot systems in terms of production throughput compared to systems without a controller.

1 October 2025 in Biomimetics
Verified
Journal Article
Open access
PDF file
MÖMete Özbaltan
Mete Özbaltan
SÇserkan çaşka
serkan çaşka
MYMerve YILDIRIM
Merve YILDIRIM
CŞCihat ŞEKER
Cihat ŞEKER
FAFaruk Emre Aysal
Faruk Emre Aysal
EKEmrah Kuzu
Emrah Kuzu
In this study, we propose an architectural model for path optimization in cluster order picking within warehouse robotics, utilizing a hybrid approach that combines symbolic control and metaheuristic techniques. Among the optimization strategies, we incorporate bio-inspired metaheuristic algorithms such as the Walrus Optimization Algorithm (WOA), Puma Optimization Algorithm (POA), and Flying Foxes Algorithm (FFA), which are grounded in behavioral models observed in nature. We consider large-scale warehouse robotic systems, partitioned into clusters. To manage shared resources between clusters, the set of clusters is first formulated as a symbolic control design task within a discrete synthesis framework. Subsequently, the desired control goals are integrated into the model, encoded using parallel synchronous dataflow languages; the resulting controller, derived using our safety-focused and optimization-based synthesis approach, serves as the manager for the cluster. Safety objectives address the rigid system behaviors, while optimization objectives focus on minimizing the traveled path of the warehouse robots through the constructed cost function. The metaheuristic algorithms contribute at this stage, drawing inspiration from real-world animal behaviors, such as walruses’ cooperative movement and foraging, pumas’ territorial hunting strategies, and flying foxes’ echolocation-based navigation. These nature-inspired processes allow for effective solution space exploration and contribute to improving the quality of cluster-level path optimization. Our hybrid approach, integrating symbolic control and metaheuristic techniques, demonstrates significantly higher performance advantage over existing solutions, with experimental data verifying the practical effectiveness of our approach. Our proposed algorithm achieves up to 3.01% shorter intra-cluster paths compared to the metaheuristic algorithms, with an average improvement of 1.2%. For the entire warehouse, it provides up to 2.05% shorter paths on average, and even in the worst case, outperforms competing metaheuristic methods by 0.28%, demonstrating its consistent effectiveness in path optimization.

25 February 2025 in EURASIP Journal on Information Security
Verified
Journal Article
Open access
PDF file
HYHazal Su Bıçakcı Yeşilkaya
Hazal Su Bıçakcı Yeşilkaya
RGRichard Guest
Richard Guest
With the advancement of technology and the increasing use of wearable devices, information security have become a necessity. Although many biometrics authentication methods have been studied on these devices to ensure information security, an activity-aware deep learning (DL) model that is compatible with different device types and uses only electrocardiogram signals has not been studied. Our objective is to investigate DL models that exclusively use ECG signals during several physical activities, facilitating their implementation on various devices. Through this research, we aim to contribute to the advancement of wearable devices for the purpose of biometric verification. In this context, this study investigates the application of adaptive techniques that rely on prior activity classification to potentially improve biometric performance using DL models. In this study, we compare three time-frequency representations to generate images for activity classification using GoogleNet, ResNet50 and DenseNet201, and for biometric verification using ResNet50 and DenseNet201. Despite employing various convolutional neural network (CNN) models, we could not achieve high accuracy in activity classification. Consequently, manually classified samples were used for activity-aware biometric verification. We also provide a detailed comparison of various DL parameters. We use a public dataset simultaneously collected from both medical and wearable devices to offer a cross-device comparison. The results demonstrate that our method can be applied to both wearable and medical devices for activity classification and biometric verification. Besides, although it is known that DL requires a large amount of training data, our model, which was created using a small amount of training data and a real-life biometric verification scenario, achieved comparable results to studies using a large amount of data. The model was achieved 0.16% to 30.48% better results when classified according to their physical activities.