Hacettepe Üniversitesi Açık Erişim Sistemi (HÜAES)
- HÜAES, Hacettepe Üniversitesi bünyesinde üretilen kitap, makale, tez, bildiri, rapor gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, etkisini artırmak için telif haklarına uygun olarak Açık Erişime sunar.
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Recent Submissions
A Learning-Based Fault Detection Approach for Unmanned Aerial Systems Using Inertial Sensor Data
(Fen Bilimleri Enstitüsü, 2026) Furkan YÜKSEL; Bilgisayar Mühendisliği
This thesis presents a lightweight embedded fault detection framework for identifying propulsion system faults in Unmanned Aerial Vehicles (UAVs) using inertial sensor measurements. Mechanical degradation, imbalance, and physical damage affecting motors and propellers may reduce flight performance and compromise operational safety. Consequently, there is an increasing need for fault detection methods capable of operating in real time on resource-constrained embedded platforms.
The proposed approach utilizes three-axis acceleration and angular velocity measurements acquired from an onboard Inertial Measurement Unit. First, the raw sensor measurements undergo a lightweight preprocessing stage and are transformed into the frequency domain using the Fast Fourier Transform. Dominant frequencies, spectral amplitudes, band energies, and harmonic ratios are then extracted from the resulting spectrum to construct a compact feature vector.
To eliminate the need for labeled datasets, an online clustering algorithm is proposed for fault detection. The algorithm incrementally learns the characteristics of normal operating conditions and continuously evaluates newly acquired observations against the learned model. As a result, abnormal behavior can be identified without requiring an offline training stage while preserving the ability to adapt to changing operating conditions.
The proposed framework is experimentally evaluated under healthy, broken propeller, bent propeller, and direction-incompatible propeller scenarios. The results demonstrate that the method can successfully identify several abnormal operating conditions. Furthermore, power consumption, execution time, and memory analyses show that the proposed framework can operate in real time on resource-constrained embedded hardware.
Kedi Alerjenlerinin Hava Yolu Yeniden Yapılanmasına ve Oksidatif Stres Üzerine Etkisi
(Fen Bilimleri Enstitüsü, 2026) Çağla Burçin Bıçakçı; Biyoloji
In respiratory diseases, whose global prevalence is steadily increasing, exposure to allergens significantly affects the onset and severity of the disease. Airway epithelial cells, which constitute the primary barrier against inhaled allergens, protect the airways from external agents through their chemical and immune functions, as well as their physical barrier role. Airway allergens can be broadly classified as indoor and outdoor allergens. Among indoor allergens, cat allergens are among the most frequently encountered. Although there are studies in the literature demonstrating the disruptive effects of cat allergens on the epithelial barrier structure, research highlighting their impacts on oxidative stress and airway remodeling, both of which hold a pivotal role in the pathology of respiratory diseases, remains limited and insufficient.
This thesis aims to investigate the effects of Fel d 1 and Cat Dander Extract (CDE) allergens on processes associated with airway remodeling and oxidative stress. In this context, a co-culture system comprising bronchial epithelial cells (16HBE14o-) and fibroblast cells (CCD-16Lu) was established to mimic the airway microenvironment. To evaluate airway remodeling, the protein expressions of α-SMA, Vimentin, and Collagen I in CCD-16Lu cells were analyzed via Western Blotting, while their gene expression levels were examined using Real-Time Polymerase Chain Reaction (qPCR). The levels of Matrix Metalloproteinases (MMP-2, MMP-9) and their tissue inhibitors (TIMP-1, TIMP-2) were measured by Enzyme-Linked Immunosorbent Assay (ELISA), and their corresponding gene expressions were determined in CCD-16Lu cells. Oxidative stress parameters were evaluated using 16HBE14o- cells. The gene expressions of HMOX1, NOX4, TXNRD1, and GPX4, which are associated with oxidative stress and antioxidant activity, were analyzed by Real-Time PCR, and total intracellular ROS levels were determined through ROS assays.
Following the experiments and data analyses, a dose-dependent increase in the gene and protein expressions of α-SMA and Collagen I, key markers associated with airway remodeling, was detected upon stimulation with both allergens. ELISA results revealed an alteration in the MMP/TIMP balance, indicating that allergen-stimulated cells failed to tolerate the accumulation of proteins such as collagen. The dose- and allergen-dependent increases observed in TIMP-1 and TIMP-2 levels suggest a cellular response activated to counteract the tissue damage induced by the allergens.
Overall, the findings of this thesis demonstrate that airway remodeling and oxidative stress, which play crucial roles in respiratory diseases such as asthma, are significantly affected by cat allergens, and the underlying mechanisms vary depending on the specific allergen stimulation.
FARKLI TARIM YÖNTEMLERİ VE HASAT ZAMANININ DOMATESLERİN ANTİOKSİDAN BİLEŞİKLERİ VE ANTİOKSİDAN AKTİVİTESİ ÜZERİNE ETKİSİ
(2026) AYLİN İŞLER; Beslenme Bilimleri
Tomato (Solanum lycopersicum) is an important fruit in human nutrition due to its rich content of bioactive compounds with antioxidant properties, including lycopene, β-carotene, ascorbic acid, and phenolic compounds. The antioxidant activity of tomatoes may be influenced by several factors such as genotype, environmental conditions, harvest time, and cultivation practices. This study aimed to compare the antioxidant activities of tomatoes cultivated under organic (Afyon-Başmakçı), conventional (Denizli-Sarayköy), and soilless (Afyon-Sandıklı) agricultural production systems, with samples collected in June and August. The samples were freeze-dried and extracted with 80% ethanol, and their antioxidant activities were evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Antioxidant activity was determined by calculating the half-maximal inhibitory concentration (IC₅₀) values of the extracts. The IC₅₀ values of the tomato samples ranged between 97.93 and 947.10 µg/mL. Among the samples
harvested in June, the highest antioxidant activity was observed in the soilless-grown tomato (H.T.: 423.54 µg/mL), followed by conventional (H.K.: 486.15 µg/mL) and organic (H.O.: 670.18 µg/mL) samples. Among the samples harvested in August, the
highest antioxidant activity was observed in the conventional sample (A.K.: 97.93 µg/mL), followed by organic (A.O.: 898.15 µg/mL) and soilless-grown (A.T.: 947.10 µg/mL) samples. When compared across harvest periods, antioxidant activity increased in the conventional sample from June to August, whereas it decreased markedly in both organic and soilless-grown samples. These findings demonstrated that antioxidant activity varied considerably not only by cultivation method but also by harvest time. In conclusion, the antioxidant activity of tomatoes appears to be influenced not only by cultivation method but also by factors such as harvest time, environmental conditions, and genotype. Therefore, the evaluation of different agricultural production systems should consider all factors affecting nutritional quality rather than cultivation method alone.
OTİZMLİ ÇOCUKLARIN EBEVEYNLERİNDE PSİKOLOJİK DAYANIKLILIK, OKUPASYONEL KATILIM, YETERLİLİK VE DENGENİN İNCELENMESİ
(Sağlık Bilimleri Enstitüsü, 2026-06-30) Gamze Ayşe Kellecioğlu; Ergoterapi
Kellecioğlu, A.G., Investigation of Psychological Resilience, Occupational
Participation, Competence, and Balance in Parents of Children with Autism,
Hacettepe University Health Sciences Graduate School Occupational Therapy
Program Master's Thesis, Ankara, 2026. This research aimed to examine the
occupational balance, participation, and psychological resilience in parents of children
with autism. The study included 56 parent dyads (total n=112) of children with Autism
Spectrum Disorder (ASD). Data were collected via face-to-face interviews using the
Occupational Balance Questionnaire (OBQ11-T), Model of Human Occupation
Screening Tool (MOHOST), Occupational Self-Assessment (OSA), and Resilience
Scale for Adults (RSA). Results showed no significant differences in total scores of
occupational balance, competence, and resilience between genders (p>0.05).
However, in MOHOST subscales, mothers scored significantly higher in Volition
(p=0.047), Habituation (p=0.002), and Environment (p=0.035) than fathers. Total
MOHOST scores were significantly higher in favor of mothers (Med: 63.5) than
fathers (Med: 60.0) (p=0.004). OSA data revealed that while responsibility
competence was high in both groups, mothers scored significantly lower in personal
occupations like self-care and leisure (p<0.05). A positive, moderate correlation was
found between fathers' resilience and mothers' occupational participation (rho=0.305;
p=0.022). Significant positive correlations also existed between mothers' occupational
balance and their resilience (rho=0.287) and competence perceptions (rho=0.402). In
conclusion, although mothers have higher occupational participation levels, they
experience significant restrictions in personal occupations; as fathers' psychological
resilience increases, mothers' occupational participation also increases, and fathers'
psychological resilience shows a significant positive correlation with mothers'
participation process. Based on these findings, developing family-based occupational
therapy strategies aimed at increasing fathers' resilience to balance the maternal
occupational burden are recommended.
Gastrointestinal Sistem Kanseri Tanısı Konmuş Hastaların Beslenme Durumu ve Yaşam Kalitesinin Değerlendirilmesi
(Sağlık Bilimleri Enstitüsü, 2026) Şimşek, Gamze; Beslenme ve Diyetetik
Şimşek G., Assessment of Nutritional Status and Quality of Life in Patients with Gastrointestinal Cancer, Hacettepe University Graduate School of Health Sciences, Dietetics Program Master’s Thesis, Ankara, 2026. This study, conducted to evaluate the relationship between adherence to the Mediterranean diet and the nutritional status and quality of life of patients with Gastrointestinal (GI) cancer, was carried out between September 2025 and April 2026 at University Hospital. A total of 117 individuals diagnosed with GI cancer (61 men and 56 women), with a median age of 63.0 years, were included in the study. A face-toface questionnaire was administered to determine the demographic and anthropometric characteristics and the medical histories of the participants. Participants' dietary intake was assessed using a food frequency questionnaire, their adherence to the Mediterranean diet using the Mediterranean Diet Adherence Screener (MEDAS), their malnutrition status using the Nutritional Risk Screening (NRS-2002), and their quality of life using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). A decrease was found in participants' body weight and Body mass index (BMI) values between the pre-diagnosis period and the time of the interview (p<0.001). 48.7% of the participants (n=57) were found to adhere to the Mediterranean diet, while 51.8% (n=60) were found not to adhere to it. Among individuals adhering to the Mediterranean diet, consumption of vegetables, fruits, eggs, and dried legumes/oilseeds was found to be higher than among those who did not adhere to the diet (p<0.05). Among individuals adhering to the Mediterranean diet, social functioning scores were found to be higher (p<0.05) and economic hardship scores were found to be lower (p<0.05) compared to those who did not adhere to the diet. Compared with individuals not at risk, those at risk of malnutrition had lower Global Health Status/QoL (p<0.05), Physical Functioning (p<0.001), Role Functioning (p<0.05), and Social Functioning (p<0.001) scores, and higher Fatigue (p<0.001), Nausea/Vomiting (p<0.05), Pain (p<0.05), Appetite Loss (p<0.001), and Financial Difficulties (p<0.05) scores. The percentage of weight loss was negatively correlated with Global Health Status/QoL, Physical Functioning, and Role Functioning, and positively correlated with Fatigue, Appetite Loss, Financial Difficulties, Pain, Dyspnoea, and Nausea/Vomiting (p<0.05). Daily protein (g) and energy (kcal) intake was positively associated with Global Health Status/QoL and negatively associated with Fatigue and Appetite Loss scores; and daily fiber (g) intake was negatively associated with Fatigue and Appetite Loss scores (p<0.05). Age (p=0.002) and current BMI (p<0.05) were identified as independent risk factors for malnutrition risk. MEDAS adherence showed a borderline significant protective effect against malnutrition risk (p=0.05). The risk of malnutrition (p<0.05) and protein intake (g/kg) (p<0.05) were identified as independent determinants of low quality of life. Early nutritional assessment and intervention in patients with GI cancer are critical for improving their quality of life. Keywords