Atılım Academic Archive (Atılım University)
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Evaluating and Improving Mobile Security Through User-Centred Approaches
No full textMobil uygulamalar günümüzde bireylerin finansal, tıbbi ve kişisel etkileşimlerinin giderek artan bir kısmını yönetmektedir. Ancak güvenlik araştırmaları hâlâ büyük ölçüde kod düzeyindeki açıklar üzerine yoğunlaşmakta ve sıradan kullanıcıların bu koruma mekanizmalarıyla nasıl etkileşime geçtiğini göz ardı etmektedir. Bu boşluğu kapatmak amacıyla, OWASP Mobile Top 10, MITRE ATT&CK ve güncel akademik literatürde tanımlanan teknik tehditleri sade bir dille sekiz uygulanabilir adıma dönüştüren bir kontrol listesi geliştirilmiştir. Bu adımlar; aşırı izin verme, güvensiz ağ kullanımı ve zayıf kimlik doğrulama gibi temel güvenlik açıklarını hedef alır ve teknik olmayan terimlerle ifade edilerek geniş bir kullanıcı kitlesi için erişilebilir hale getirilmiştir. Çalışma üç aşamalı bir yöntem izlemiştir: zafiyet analizi yoluyla kontrol listesi geliştirme, kullanıcı davranışlarını ve liste kullanımını değerlendiren bir anket uygulaması ve katılımcı geri bildirimlerine dayalı rehber ilke oluşturma. Geliştirilen kontrol listesi, yaş, platform ve siber güvenlik deneyimi bakımından çeşitlilik gösteren 42 Android ve iOS kullanıcısıyla test edilmiştir. Katılımcıların %83'ü kontrol listesindeki adımların çoğunu tamamlamış, %70'ten fazlası ise mobil riskler konusunda farkındalıklarının arttığını bildirmiştir. Bu bulgulara dayanarak teknik standartlarla kullanıcı pratiği arasındaki boşluğu doldurmayı amaçlayan on ilke geliştirilmiştir. Her ilke, belirli kullanıcı eylemlerini bilinen zafiyetlerle eşleştirmekte ve OWASP ile MITRE gibi güvenlik çerçeveleriyle uyum göstermektedir. Sonuçlar, teknik temelli davranışsal içgörülerle geliştirilen kullanıcı odaklı araçların farkındalığı artırma ve daha güvenli alışkanlıklar kazandırma potansiyeline sahip olduğunu vurgulamaktadır.Mobile apps now mediate a growing share of people's financial, medical, and personal exchanges, yet most security research still concentrates on code‑level flaws and overlooks how ordinary users interact with those protections. To close this gap, we designed a plain‑language checklist that translates recognized technical threats synthesized from OWASP Mobile Top 10, MITRE ATT&CK, and recent peer-reviewed literature into eight actionable steps covering both device settings and everyday behaviors. These steps address core vulnerability areas such as over-permissioning, insecure network use, and weak authentication, and are framed in non-technical terms to ensure accessibility across a wide user base. The study employed a three-phase methodology: checklist development through vulnerability analysis, a user survey assessing behavior and checklist usage, and guideline formulation based on participant feedback. We evaluated the checklist with 42 Android and iOS users representing a range of ages, platforms, and cybersecurity experience levels. The results show that 83 percent of participants completed most of the checklist items, while over 70 percent reported improved awareness of mobile risks. These challenges were echoed in a complementary survey of broader mobile security habits, which confirmed additional blind spots, most notably, low rates of VPN and antivirus usage. Building on these insights, we formulated a set of ten guidelines designed to bridge technical standards and user practice. Each guideline maps specific user actions to known vulnerabilities and aligns with cybersecurity frameworks such as OWASP and MITRE. The findings underscore the importance of combining behavioral insight with technical frameworks
The Great Kapok Tree Growing With Turkish Children: A Kincentric ‘Writing Project’
No full textEnvironmental problems, increasingly felt on a global scale, have necessitated environmental education from a very young age, a vital component of sustainable development efforts. As an integral part of this education, environmental children’s literature, especially picturebooks, can give young children the necessary knowledge, cultivate environmental awareness, help develop sustainable behavioral patterns, and increase environmental literacy. In a similar vein, translated picturebooks can create comparable impacts through intentional translational strategies adopted by all translation agents involved in the process. Approaching translation as a writing project, this study aims to explore how the Turkish translation of the environmental picturebook, The Great Kapok Tree, can help foster a kincentric worldview through adding and omitting semiotic modes in the target text and analyze how these changes may transform and potentially enhance or diminish environmental messages in the translated version. The findings reveal the efficacy of the translator’s and other translation agents’ active involvement in the translation process by framing the translation as a writing project that can reshape the source text to achieve environmental and educational goals. © The Author(s), under exclusive licence to Springer Nature B.V. 2025
Design and Fabrication of Dual-Layered PCL/PEG Theranostic Platforms Using 3D Melt Electrowriting for Targeted Delivery and Post-Treatment Monitoring
No full textAdvanced pancreatic tumors remain highly resistant to treatment due to their dense stromal environment and poor vascularization, which limit drug penetration and efficacy. Even after surgical resection, the high recurrence rate frequently leads to poor prognosis and mortality. To address these challenges, we developed solvent-free three-dimensional (3D) melt electrowritten (MEW) theranostic microfiber patches composed of poly(epsilon-caprolactone) (PCL) and polyethylene glycol (PEG). The patches were designed as dual-layered, 10-layer structures, with gemcitabine (GEM) loaded in the bottom five layers for localized chemotherapy to suppress tumor recurrence, and indocyanine green (ICG) incorporated in the top five layers to enable fluorescence-based post-surgical monitoring. Following fabrication, the patches were characterized both materially and in vitro, with GEM loaded at 100, 250, or 500 mu g/ml. PEG incorporation improved patch flexibility, facilitating the implantation process. In vitro release analysis demonstrated an initial burst followed by sustained, pH-responsive GEM release (similar to 70% at pH 4.0 and similar to 30% at pH 7.4 for 500 mu g/mL GEM at 168 h), while ICG release reached similar to 25% (pH 7.4) and similar to 10% (pH 4.0). GEM-loaded patches significantly reduced Capan-1 cell viability in a dose- and time-dependent manner, achieving >= 50% reduction at 72 h with 500 mu g/mL. Importantly, ICG incorporation did not impair GEM cytotoxicity; confocal imaging confirmed ICG internalization in viable cells and showed a decline in ICG-positive cells with increasing GEM dose, supporting the potential for concurrent therapy and monitoring. Thus, the theranostic patches enable localized, pH-responsive GEM delivery with integrated ICG-based fluorescence imaging, achieving significant cytotoxicity against pancreatic cancer cells while providing a platform for post-surgical surveillance. This solvent-free, layer-addressable approach represents a promising strategy for personalized, locally implantable theranostic systems in pancreatic cancer treatment.Scientific and Technological Research Council of Turkiye (TUBITAK) [2218-118C547]This study was funded by the Scientific and Technological Research Council of Turkiye (TUBITAK) under Project No. 2218-118C547
Intrusion Detection in IoT Using Machine Learning: A Focus on the Network Layer With the TON-IoT Dataset
No full textNesnelerin İnterneti (IoT), modern ağ sistemlerini dönüştürürken, çeşitli ve kaynak kısıtlı mimarisi nedeniyle önemli güvenlik risklerini de ortaya çıkarmıştır. Geleneksel Saldırı Tespit Sistemleri (IDS), özellikle ağ katmanında IoT tehditlerinin gelişen özelliklerini yeterince karşılayamamaktadır. Bu tez, ToN-IoT veri kümesi için özel olarak tasarlanmış, özellik-iyileştirmeli makine öğrenimine dayalı bir Ağ Saldırı Tespit Sistemi (NIDS) sunmaktadır. Önerilen çok aşamalı çerçeve, boyutluluğu azaltmak, fazlalığı gidermek ve gerçek zamanlı performansı iyileştirmek amacıyla istatistiksel (Pearson, Spearman, Ki-Kare) ve gömülü (Random Forest) öznitelik seçimi yöntemlerini bütünleştirmektedir. İkili ve çok sınıflı saldırı tespiti görevleri için Lojistik Regresyon, En Yakın Komşular (KNN), Karar Ağacı, Rastgele Orman (RF), Gauss Naive Bayes, Yapay Sinir Ağları (ANN), XGBoost, Gradient Boosting, AdaBoost ve ExtraTrees dâhil olmak üzere geniş bir sınıflandırıcı kümesi üzerinde kapsamlı karşılaştırmalar gerçekleştirilmiştir. Değerlendirme metrikleri F1-skoru, AUC, MCC ve çıkarım gecikmesini içermektedir. Bulgular, özellik seçiminin verimli sınıflandırıcılarla entegrasyonunun tespit doğruluğunu ve kaynak kısıtlı ortamlardaki operasyonel uygulanabilirliği önemli ölçüde artırdığını göstermektedir. Bu tez, IoT güvenlik uzmanları için çoğaltılabilir bir çerçeve ve pratik içgörüler sunarak sınıflandırıcı karmaşıklığı, yorumlanabilirlik ve gerçek zamanlı uygulanabilirlik arasındaki dengeyi vurgular. Elde edilen sonuçlar, ölçeklenebilir ve gelişmiş IoT güvenlik mimarileri için pragmatik bir temel sağlamaktadır.The Internet of Things (IoT) has revolutionized modern networked systems while simultaneously exposing significant security risks due to its diverse and resource limited architecture. Conventional Intrusion Detection Systems (IDS) inadequately meet the evolving characteristics of IoT threats, particularly at the network layer. This thesis presents a feature-optimized machine learning-based Network Intrusion Detection System (NIDS) specifically designed for the ToN-IoT dataset. We propose a multi-stage framework that integrates statistical (Pearson, Spearman, Chi-Square) and embedding (Random Forest) feature selection methods to decrease dimensionality, alleviate redundancy, and improve real-time performance. Comprehensive benchmarking is conducted across a diverse set of classifiers, including Logistic Regression, K-Nearest Neighbors (KNN), Decision Tree, Random Forest (RF), Gaussian Naive Bayes, Artificial Neural Networks (ANN), XGBoost, Gradient Boosting, AdaBoost, and ExtraTrees, for both binary and multiclass intrusion detection tasks. The assessment metrics comprise F1-score, AUC, MCC, and inference latency. The findings indicate that integrating feature selection with efficient classifiers markedly enhances detection accuracy and operational feasibility in resource-limited settings. This thesis provides a replicable framework and practical insights for IoT security professionals, emphasizing the trade-offs among classifier complexity, interpretability, and real-time applicability. The results provide a pragmatic basis for scalable and sophisticated IoT security architectures
Adaptive Reuse in Traditional Residential Architecture: The Case of Beypazari Taş Mektep
No full textBu tez çalışması, Beypazarı'nda yer alan Taş Mektep yapısının mimari ve işlevsel dönüşümünü ele almaktadır. Yapının ne zaman, kim tarafından ve hangi amaçla inşa edildiğine dair kesin bir belge bulunmamaktadır. 1763 yılında yazılan bir vakfiyede, Cami-i Kebir'in yanında bir mektepten söz edilmektedir. Taş Mektep'in Kurşunlu Camii'nin hemen bitişiğinde konumlanmasından dolayı bahsedilen mektebin burada yer aldığı düşünülmektedir. Bununla birlikte, literatür taramasında yapının 19. yüzyıl Osmanlı konut mimarisine özgü nitelikler taşıyan bir eğitim yapısı olduğu vurgulanmaktadır. Osmanlı döneminde sıbyan mektebi olarak kullanılan yapı, Cumhuriyet döneminde de eğitim işlevini sürdürmüş; 20. yüzyılda restorasyon sonrasında restoran olarak değerlendirilmiştir. Çalışmada vakfiye belgeleri, literatür taraması, arşiv fotoğrafları ve yerinde inceleme bulguları karşılaştırmalı olarak değerlendirilmiştir. Malzeme kullanımı, mekânsal organizasyon ve cephe özellikleri incelenerek yapının tarihsel sürekliliği ve geçirdiği değişimler ortaya konmuştur. Beypazarı Taş Mektep, geleneksel konut mimarisinin mekânsal düzenini eğitim işleviyle bütünleştiren özgün bir örnek olarak değerlendirilmektedir. Yapı, yalnızca fiziksel özellikleriyle değil, kentsel bellekteki simgesel değeriyle de korunması gereken önemli bir kültürel mirastır. Bu yönüyle yapı, tarihsel sürekliliği ve geçirdiği işlevsel değişimleriyle, kültürel mirasın korunması ve yeniden değerlendirilmesi bağlamında bir örnek niteliği taşımaktadır.This thesis examines the architectural and functional transformation of the Taş Mektep building located in Beypazarı. There is no definitive evidence regarding when, by whom, and for what purpose the structure was constructed. A vakfiye dated 1763 refers to a school situated next to the Cami-i Kebir. Given that Taş Mektep is positioned immediately adjacent to the Kurşunlu Mosque, it is assumed that the mentioned school may have been located here. Nevertheless, the literature emphasizes that the building represents an educational structure bearing the characteristics of nineteenth-century Ottoman residential architecture. Used as a sıbyan mektebi during the Ottoman period, the building continued to serve an educational function in the Republican era and, following restoration in the twentieth century, was adapted for use as a restaurant. In the study, vakfiye documents, literature review, archival photographs, and on-site observation findings were comparatively evaluated. By examining material use, spatial organization, and façade features, the historical continuity of the building and the transformations it underwent were revealed. The Beypazarı Taş Mektep is evaluated as a unique example that integrates the spatial layout of traditional residential architecture with an educational function. The building, not only with its physical characteristics but also with its symbolic value in urban memory, is an important cultural heritage that should be preserved. In this respect, with its historical continuity and functional transformations, the building constitutes an example in the context of the conservation and reuse of cultural heritage
The Sixth International Workshop on Nonlinear Analysis and Its Applications Preface by the Guest Editors
No full textFixed Point Results on Perturbed B-Metric Space
No full textIn this paper, we introduce the notion of perturbed b-metric spaces and consider some basic topological notions on this new abstract structure. In addition, we shall discuss the existing and uniqueness of a fixed point in the setting of perturbed b-metric spaces
Development and In-Vitro Evaluation of Gallium-68 Labelled Staphylococcus Aureus-Specific Aptamer as a Potential PET Agent for Infection Imaging
No full textBackground: Staphylococcus aureus (S. aureus) is the most common causative pathogen associated with a wide range of infections, from mild to life-threatening conditions such as osteomyelitis, endocarditis, and pneumonia. Early detection and reliable differentiation between infection and sterile inflammation are essential for accurate diagnosis and effective treatment. However, most radiopharmaceuticals currently available fail to discriminate between these conditions, underscoring the need for infection-specific imaging agents. Materials and Methods: In this study, a Gallium-68 (Ga-68)-labeled S. aureus-specific aptamer was developed as a potential PET infection imaging probe. Aptamers were selected using the cell-systematic evolution of ligands by exponential enrichment (SELEX) method, and their specificity was verified by fluorescence-based binding assays. Radiolabeling was achieved via DOTA chelation, and radiochemical purity was determined. Additionally, in vitro binding assays were performed with S. aureus, while Escherichia coli (E. coli) served as a control. Results: The aptamer exhibited an affinity constant (Kₐ) of 2260 ± 634 CFU/ mL and a linear detection range of 250-2×10⁴ CFU/mL, with a limit of detection of 171 CFU/mL for S. aureus. The Ga-68-labeled aptamer demonstrated radiochemical purity greater than 99%. In vitro binding increased linearly with rising S. aureus concentrations (10³-2×10⁴ CFU/mL), while minimal binding to E. coli confirmed its specificity. Conclusion: These results demonstrate that the Ga-68-labeled S. aureus-specific aptamer holds promise as an infection-targeted PET imaging agent. Although currently limited to in vitro evaluation, such aptamer-based radiopharmaceuticals may contribute to improved diagnosis and imaging of infectious diseases. © 2025, Novin Medical Radiation Institute. All rights reserved
