Işık Üniversitesi Kurumsal Akademik Bellek
Işık Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Transmission of spatial experience in the context of sustainability of urban memory
(Multidisciplinary Digital Publishing Institute (MDPI), 2024-11) Cankurt Semiz, Sedef Nur; Özsoy, Fatma Ahsen
Urban memory involves the re-creation of a city’s physical, historical, social, and cultural elements in the memories of its inhabitants. However, urban transformation and commercial tourism-oriented projects may threaten the continuity of this memory. This study aims to provide an understanding of the relationship between urban memory and spatial experience while exploring how urban memory elements convey meanings to daily users and local inhabitants of a touristic settlement. The research focuses on Misi Village in Bursa, Turkey, a settlement with a 2000-year history known for its traditional architecture and natural beauty. Over the past two decades, local authorities have pursued extensive restoration projects to rebrand Misi Village as an Art and Tourism Village. The research employs the oral history method, focusing on two user groups: tourists and locals. The findings reveal that while tourists appreciate Misi Village for its natural beauty and recreational activities, they lack a deeper understanding of its history and the transformation of its identity. Instead, they mostly focus on commerce-oriented spatial experiences. In contrast, local residents emphasize daily life and traditional practices as they strive to sustain their livelihoods. By highlighting this difference, strategic planning is proposed to preserve Misi Village’s unique urban memory and promote sustainable, culturally centered tourism.
TURSpider: a Turkish Text-to-SQL dataset and LLM-based study
(Institute of Electrical and Electronics Engineers Inc., 2024-11-25) Kanburoğlu, Ali Buğra; Tek, Faik Boray
This paper introduces TURSpider, a novel Turkish Text-to-SQL dataset developed through human translation of the widely used Spider dataset, aimed at addressing the current lack of complex, cross-domain SQL datasets for the Turkish language. TURSpider incorporates a wide range of query difficulties, including nested queries, to create a comprehensive benchmark for Turkish Text-to-SQL tasks. The dataset enables cross-language comparison and significantly enhances the training and evaluation of large language models (LLMs) in generating SQL queries from Turkish natural language inputs. We fine-tuned several Turkish-supported LLMs on TURSpider and evaluated their performance in comparison to state-of-the-art models like GPT-3.5 Turbo and GPT-4. Our results show that fine-tuned Turkish LLMs demonstrate competitive performance, with one model even surpassing GPT-based models on execution accuracy. We also apply the Chain-of-Feedback (CoF) methodology to further improve model performance, demonstrating its effectiveness across multiple LLMs. This work provides a valuable resource for Turkish NLP and addresses specific challenges in developing accurate Text-to-SQL models for low-resource languages.
Visible light communication with solar cell receiver for indoor IoT applications
(Institute of Electrical and Electronics Engineers Inc., 2024) Bonakdar, Roozbeh; Edemen, Çağatay; Akbulut, Muhammed Emin; Keskin, Onur; Kaya, Onur; Uysal, Murat
The rapid increase of Internet of Things (IoT) devices has ushered in a new era of connectivity, with an increasing reliance on efficient communication models. In this context, Optical Wireless Communications (OWC) presents a promising avenue for transmitting data at the speed of light, utilizing the optical spectrum to alleviate congestion in urban environments. Leveraging Light Emitting Diodes (LEDs) as transmitters and solar cells as receivers, this paper explores the feasibility of indoor OWC systems. Moreover, we present an experimental setup focusing on bandwidth measurement, data transmission, and energy harvesting. Our results indicate a maximum data rate of 19.2 Kbps using On-Off Keying (OOK) modulation at a 15 cm link distance. Notably, by avoiding the utilization of external circuitry for performance enhancement of the solar cell, we tried to maintain the system's suitability for IoT applications. Our findings contribute to understanding solar cell-based data reception from LEDs, offering simulation results for practical implementation and performance considerations for indoor IoT communication systems.
Effect of mechanically exfoliated graphite flakes on morphological, mechanical, and thermal properties of epoxy
(Multidisciplinary Digital Publishing Institute (MDPI), 2024-11-11) Gül, Ayşenur; Kamali, Ali Reza
Carbon-reinforced polymer composites form an important category of advanced materials, and there is an increasing demand to enhance their performance using more convenient and scalable processes at low costs. In the present study, graphitic flakes were prepared by the mechanical exfoliation of synthetic graphite electrodes and utilized as an abundant and potentially low-cost filler to fabricate epoxy-based composites with different additive ratios of 1–10 wt.%. The morphological, structural, thermal, and mechanical properties of these composites were investigated. It was found that the thermal conductivity of the composites increases by adding graphite, and this increase mainly depends on the ratio of the graphite additive. The addition of graphite was found to have a diverse effect on the mechanical properties of the composites: the tensile strength of the composites decreases with the addition of graphite, whilst their compressive strength and elastic modulus are enhanced. The results demonstrate that incorporating 5 wt% of commercially available graphite into epoxy not only raises the thermal conductivity of the material from 0.223 to 0.485 W/m·K, but also enhances its compressive strength from 66 MPa to 72 MPa. The diverse influence of graphite provides opportunities to prepare epoxy composites with desirable properties for different applications.
Investigation of residual stresses induced by turning of hot forged and heat treated AA7075
(Springer Science and Business Media Deutschland GmbH, 2024-12) Tok, Görkem; Kuzu, Ali Taner; Bakkal, Mustafa
This study investigates the impact of cutting parameters on residual stress in components made from AA7075 material, which were hot forged and subsequently subjected to T6 heat treatment. Using the Taguchi experimental design, two distinct cutting cases—face turning and circumferential turning—were devised to assess residual stress at different sections of the part. During the turning process, force measurements were conducted with a dynamometer, and residual stress was subsequently measured using the X-ray diffraction method. The results indicate that both mechanical and thermal loadings significantly influence residual stress. Notably, spindle speed has the most substantial effect on residual stress in both face turning and circumferential turning, with an observed increase of up to 30% and 20%, respectively, in tensile residual stress for Case 1 and Case 2. When thermal loads are predominant, residual stress tends to be tensile, with measurements reaching as high as 89 MPa.
