Yazar "Gursel, Amira Tandirovic" seçeneğine göre listele

Listeleniyor 1 - 7 / 7
  • [ X ]
    Öğe
    A Laser Points Toward Disease Diagnosis
    (Laurin Publishing Co. Inc., 2020) Gursel, Amira Tandirovic
    According to the latest reports from the United Nations Department of Economic and Social Affairs and the World Health Organization (WHO)1,2, life expectancy has more than doubled in the last two centuries, from less than 30 years to over 70, thanks to both life-saving scientific innovations and health improvements.
  • [ X ]
    Öğe
    Classification of EEG Signals in Neuromarketing Implementation Task
    (Institute of Electrical and Electronics Engineers Inc., 2021) Oran, Samet; Gursel, Amira Tandirovic
    In this work, EEG signals that are showing the frequency of the power bands were examined by wavelet power spectrum through neuromarketing outline in order to predict purchaser appetites while they look E-commerce goods. When extraction of these power bands, fixed overlap segment and 3 different sample lengths were counted in sliding window technique. k-NN was implemented for evaluating classification accuracy. The best result, 70.24% k-NN accuracy was obtained for 2-seconds sample length. © 2021 Chamber of Turkish Electrical Engineers.
  • [ X ]
    Öğe
    Modified all-GaN multidevice interleaved boost converter topology for hybrid electrical vehicles and its miniaturization
    (Springer Heidelberg, 2024) Gursel, Amira Tandirovic; Zulfikaroglu, Ali
    In inverter technology for hybrid and electric vehicles, some properties, such as low weight, compactness, small size, high power density, and high efficiency, are highly required because they affect vehicle production costs and fuel economy. Bringing reliable and cheap devices with high response rates into being, which is in close relation with circuit design, miniaturization, and appropriate selection of components, have become one of the main topics of scientific research in electronics. One of the main obstacles to achieving these goals is the bulkiness of inductors and capacitors. These essential building blocks of the converter topology are used to reduce input current and output voltage ripples, which are closely related to thermal stress in batteries, affecting their lifespan. This study proposes a GaN-based multidevice interleaved boost converter (MDIBC) topology for hybrid vehicles. The topology is investigated in terms of power loss, efficiency, current and voltage ripples, and size of passive components under two salient case studies at various switching frequencies. In both cases, current and voltage are reduced by smaller values of passive components without sacrificing efficiency. Efficiencies ranging between 97.34 and 97.83%, are achieved with passive components remaining in the benchmark converter.
  • [ X ]
    Öğe
    Morphometric effectiveness of calcium hydroxylapatite application in zygomatic and malar area on correction of nasolabial folds
    (Lippincott Williams & Wilkins, 2025) Kabakci, Ayse Gul; Gursel, Amira Tandirovic; Aydin, Baris; Eren, Dilek; Bozkir, Memduha Gulhal
    This study aims to investigate the indirect effects of calcium hydroxylapatite (CaHA) injections in the zygomatic and malar regions on the healing of nasolabial folds (NLFs). Given the anatomical complexity and proximity of the nasolabial area, selecting appropriate techniques for CaHA applications is crucial to prevent potential complications. The study is designed to contribute insights into the safety and efficacy of injections, aiming to enhance patient outcomes and minimize risks in aesthetic applications. This retrospective single-center study analyzed the effectiveness of CaHA injections in the zygomatic and malar regions for correcting NLFs in 51 female participants aged between 30 and 55. Images from clinical archives were used, taken before the application and 6 months after the application. The primary outcomes were evaluated using Gabor filter analysis, Global Aesthetic Improvement Scale, and Wrinkle Severity Rating Scale, complemented by morphometric measurements using Image J 1.52a software. Measurements before and 6 months after the application revealed significant improvements in NLF length: from 2.59 +/- 0.64 cm to 2.24 +/- 0.53 cm on the right side and from 2.76 +/- 0.81 cm to 2.59 +/- 0.61 cm on the left side. This corresponds to an improvement of 13.51 % and 6.16%, respectively. Evaluations using the Wrinkle Severity Rating Scale, Global Aesthetic Improvement Scale scores, and Gabor filter analysis also demonstrated positive NLF depth post-treatment changes. The results of our study indicate that CaHA injections in the zygomatic and malar regions lead to an indirect improvement in NLFs. Furthermore, our study provides standardized quantitative methods that can be used to assess the effectiveness of treatments in the nasolabial area. These analyses offer reliable tools for evaluating aesthetic procedures and provide valuable contributions to clinical practice.
  • [ X ]
    Öğe
    Optimizing thermal load and power scaling in Er3+-doped ZBLAN fiber lasers
    (Elsevier Science Inc, 2021) Gursel, Amira Tandirovic; Kılıç, Fatih
    Thanks to characteristics such as high beam qualities and high average powers, largely founded on the outstanding characteristics of fibers as an active medium, fiber lasers have become one of the most popular laser technologies. Although most of the advantages of fiber lasers stem from their geometry, the same geometry is the main source of the limitations. In this study, we focused on managing the thermal load by variable absorption coefficient in order to increase the thermal limits, which are an important limitation of further development in fiber technology. Metaheuristic optimization approaches can be used to improve the performance of fiber technologies with physical constraints. The main aim of metaheuristic optimization is to improve the output of the function with respect to the parameters considered as significant. Swarm Optimization approach is one of the powerful metaheuristic approaches proven to be quite promising to address the above issues. In this study, the optimization of the thermal management of the Er3+-doped ZBLAN fiber laser is performed using Artificial Bee Colony Algorithm (ABC). Additionally, this paper proposes four new strategies of initial parameter setting, repair parameter values, and fitness function for the thermal load of the Er3+-doped ZBLAN fiber laser with respect to the output power. The results show that the absorption coefficient functions obtained by ABC algorithm give more effective and efficient results than the obtained rising functions.
  • [ X ]
    Öğe
    Pep-VGGNet: A Novel Transfer Learning Method for Pepper Leaf Disease Diagnosis
    (MDPI, 2025) Cetinkaya, Sueleyman; Gursel, Amira Tandirovic
    The health of crops is a major challenge for productivity growth in agriculture, with plant diseases playing a key role in limiting crop yield. Identifying and understanding these diseases is crucial to preventing their spread. In particular, greenhouse pepper leaves are susceptible to diseases such as mildew, mites, caterpillars, aphids, and blight, which leave distinctive marks that can be used for disease classification. The study proposes a seven-class classifier for the rapid and accurate diagnosis of pepper diseases, with a primary focus on pre-processing techniques to enhance colour differentiation between green and yellow shades, thereby facilitating easier classification among the classes. A novel algorithm is introduced to improve image vibrancy, contrast, and colour properties. The diagnosis is performed using a modified VGG16Net model, which includes three additional layers for fine-tuning. After initialising on the ImageNet dataset, some layers are frozen to prevent redundant learning. The classification is additionally accelerated by introducing flattened, dense, and dropout layers. The proposed model is tested on a private dataset collected specifically for this study. Notably, this work is the first to focus on diagnosing aphid and caterpillar diseases in peppers. The model achieves an average accuracy of 92.00%, showing promising potential for seven-class deep learning-based disease diagnostics. Misclassifications in the aphid class are primarily due to the limited number of samples available.
  • [ X ]
    Öğe
    Ripple and Passive Components Reduction on All SiC Multi-Device Interleaved Boost Converter for Hybrid Electric Vehicles
    (Tafila Technical University, 2023) Zulfikaroglu, Ali; Gursel, Amira Tandirovic
    Due to a smaller environmental footprint than conventional vehicles, electric vehicles (EVs) may help in the fight against climate change. In spite of their many advantages, especially those in maintenance, disadvantages such as less traveling range, long recharging time and the high price tag-compared to gas-powered vehicles-are essential barriers to extensive usage of EVs. The forenamed limitations can be partly overcome by advancing electrical equipment in terms of efficiency, weight and compactness. The development of novel materials for circuit components and improvements in circuit design have been the primary focus of advancement with regard to DC/DC converters, one of the fundamental building blocks of electrical equipment. Therefore, this paper proposes an All-SiC-based multi-device interleaved boost converter (MDIBC) to replace the Silicon insulated gate bipolar transistors (Si IGBT)-based BC topology in Toyota Prius. To achieve high efficiency from the proposed converter, the power efficiency is examined with respect to the input current ripple values. The obtained results disclose the best efficiency is achieved for a 10% input current ripple with a 50% decrease in output voltage ripple. Additionally, for these ripple values, other decisive parameters are determined and compared to the benchmark converters. The outcomes reveal that (at 70 kHz switching frequency), the best values of inductor and capacitor with reduction in their values of 83.55% and 96.45%, respectively – are achieved. This considerable decline not only results in downsizing the passive components but also leads to a higher power density that has a crucial importance for power efficiency. © 2023, Tafila Technical University. All rights reserved.