WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
Browse
31 results
Search Results
Now showing 1 - 10 of 31
Article Geographies of Place-Affective Trans-Becoming: an Ethnography of Drag in Istanbul(Routledge Journals, Taylor & Francis Ltd, 2025) Ogut, Tuna; Kilickiran, Didem; Akpinar, IpekThis paper presents an ethnographic study of Dudaklar & imath;n Cengi, a drag and queer performing event series in Istanbul, where a community of predominantly trans and non-binary performers create a place of collectivity for self-expression and gender exploration. Drawing on trans and feminist geographical perspectives, we examine how the participants use drag as a way of creating shared imagery, exploring themselves in relation to gender, and producing places in the city through their performances beyond the stage. We conceptualise Dudaklar & imath;n Cengi as a place-as-becoming that emerges from the intensities of social ties, flows, narratives, and sensations. We also propose a geographical understanding of gendered embodiment to account for transness in new spatial ways that enable the interrogation of phenomena that do not immediately yield their relevancy to the category of gender. The data was collected in over three years of presence within the field through situated and reflexive participant observation, informal conversations, in-depth interviews, and the participants' written narratives. We analyse the data with iterative cycles of grounded theory completed with continuous collaborative theorisation with participants. Through this collaborative theorisation, a series of concepts emerge that explain the experiences of the participants: opening drag, collectivising the stage, socialising in drag, urban navigation of gender, and an unfolding sense of drag. Together, these concepts help explain a novel understanding of place-affective trans-becoming.Article Secrecy performance of full-duplex space-air integrated networks in the presence of active/passive eavesdropper, and friendly jammer(Wiley, 2024) Buyuksar, Ayse Betul; Erdoğan, Eylem; Altunbas, IbrahimIn this paper, a full-duplex (FD) space-air ground integrated network (SAGIN) system with passive and active eavesdroppers (PE/AE) and a friendly jammer (FJ) is investigated. The shadowing side information (SSI)-based unmanned aerial vehicle relay node (URN) selection strategy is considered to improve signal-to-interference plus noise power ratio (SINR) at the ground destination unit. To quantify the secrecy performance of the considered scenario, outage probability (OP), interception probability (IP), and transmission secrecy outage probability (TSOP) are investigated in the presence of FJ and PE/AE. The results have shown that aerial AE is an important threat since it can severely degrade the OP of the main transmission link. Furthermore, the FJ can decrease the IP of the eavesdropper by causing interference with the cost of power consumption of URNs. Simulations are performed to verify the theoretical findings.Article Citation - WoS: 4Citation - Scopus: 3Sediment Transport Modelling in Densly Populated Urban Areas Due To Earthfill Dam Break(Taylor & Francis Ltd, 2024) Zhang, Yaoxin; Tayfur, GokmenThis study simulates two dimensional sediment transport, as a result of overtopping earthfill dam break, in urban areas. The model can consider breaching, removal of sediment from dam body, and transport of sediment. The model is first validated by simulating laboratory experimental data that involved measurements of levels, and longitudinal sediment profiles, and sediment distribution. Downstream side of the experimental canal is designed as; (1) smooth bed, and (2) rough bed with concrete blocks. For both cases, the model simulations are found to be satisfactory. The model is then applied to simulate artificial overtopping break scenarios of two real earthfill dams. The AW3D30 is used as the source data for representing the topographic surfaces and the LULC dataset is generated from the ESA's Sentinel-2 imagery. The results reveal that downstream of the dams can be subject to both scour, at onset of the dam break, and substantial deposition after having reservoir completely emptied. The cut can go all the way to dam bed. The scoured areas can be refilled after peak discharge recedes. Sediment depths can reach up to 1.5 m in the case of Urkmez Dam break in some areas in the vicinity of Urkmez Town and up to 3 m at the downstream area of Alibey Dam in Istanbul, implying disastrous consequences for the settlement areas.Article Citation - WoS: 3Citation - Scopus: 3Development of Xylan-Coated Acid-Resistant Micellar Drug Carriers for Colon-Targeted Oral Delivery(Taylor & Francis As, 2024) Zeybek, Nuket; Polat, Hurriyet; Gulec, Sukru; Buyukkileci, Ali OguzOral delivery of hydrophobic drugs from the stomach through the colon has some requirements: (1) an acid-resistant carrier (2) a colon-specific drug release mechanism; and (3) an enhanced bioavailability. In this study, curcumin-loaded polymeric micelles with a xylan-based composite coating were designed and developed. For this purpose, a new synthesis method was used to precipitate xylan by concurrent chitosan polymerization at different xylan/chitosan ratios using a negatively charged crosslinking agent, TPP. The study was to provide the stability of the coated micellar structures in the stomach (low pH conditions) and their degradation in the colon (a natural environment of bacteria) to release the drug. It was observed that the coating successfully prevented early drug release up to 85%, depending on the fraction of xylan in the coating. The nanocarriers that first passed through the stomach conditions were incubated with a xylanolytic colonic bacterium (Bacteroides ovatus) to determine the bacterium-related release mechanism, which was around 27%. This shows the colon-specific release expectation of coated nanocarriers in the colon environment, with an additional benefit due to the degradation of xylan and an improvement in the colon environment by prebiotic activity.Article Citation - WoS: 2Citation - Scopus: 2Function Generation With Planar Four-Bar Mechanisms as a Mixed Problem of Correlation of Crank Angles and Dead Center Design(Springer india, 2024) Kadak, Tarik; Kiper, GokhanFunction generation synthesis of mechanisms can be considered as the design of correlation of crank angles and dead dead-center position design. These two problems have been clearly defined and solved separately. But some problems may require both correlation of crank angles and dead dead-center design at different configurations. Such problems are called mixed function generation problems. In this paper, an overview of these mixed function generation problems for the planar four-bar mechanism are given and the problems are solved analytically or semi-analytically. Except three of them, all presented mixed function generation problem formulations are novel. The solutions of all problems including three positions for the four-bar mechanism and the solution of a problem including four positions for a four-bar mechanism are addressed. All problems are first reduced to a univariate equation and a fast solution is found. Thus, link lengths can be found quickly by changing the problem definition problems, and several design iterations can be performed in a short time. Numerical solutions of all problems have been demonstrated using Excel.Article Citation - WoS: 3Citation - Scopus: 4Measuring the Performance of an Artificial Intelligence-Based Robot That Classifies Blood Tubes and Performs Quality Control in Terms of Preanalytical Errors: a Preliminary Study(Oxford University Press, 2024) Şişman,A.R.; Başok,B.I.; Karakoyun,I.; Çolak,A.; Bilge,U.; Demirci,F.; Başoglu,N.Objectives: Artificial intelligence-based robotic systems are increasingly used in medical laboratories. This study aimed to test the performance of KANKA (Labenko), a stand-alone, artificial intelligence-based robot that performs sorting and preanalytical quality control of blood tubes. Methods: KANKA is designed to perform preanalytical quality control with respect to error control and preanalytical sorting of blood tubes. To detect sorting errors and preanalytical inappropriateness within the routine work of the laboratory, a total of 1000 blood tubes were presented to the KANKA robot in 7 scenarios. These scenarios encompassed various days and runs, with 5 repetitions each, resulting in a total of 5000 instances of sorting and detection of preanalytical errors. As the gold standard, 2 experts working in the same laboratory identified and recorded the correct sorting and preanalytical errors. The success rate of KANKA was calculated for both the accurate tubes and those tubes with inappropriate identification. Results: KANKA achieved an overall accuracy rate of 99.98% and 100% in detecting tubes with preanalytical errors. It was found that KANKA can perform the control and sorting of 311 blood tubes per hour in terms of preanalytical errors. Conclusions: KANKA categorizes and records problem-free tubes according to laboratory subunits while identifying and classifying tubes with preanalytical inappropriateness into the correct error sections. As a blood acceptance and tube sorting system, KANKA has the potential to save labor and enhance the quality of the preanalytical process. © 2024 The Author(s).Article Citation - WoS: 5Citation - Scopus: 5Loop Based Classification of Planar Scissor Linkages(Springer, 2022) Kiper, Gökhan; Korkmaz, Koray; Gür, Şebnem; Yar Uncu, Müjde; Maden, Feray; Akgün, Yenal; Karagöz, CevahirScissor linkages have been used for several applications since ancient Greeks and Romans. In addition to simple scissor linkages with straight rods, linkages with angulated elements have been introduced in the last decades. In the related literature, two methods have been used to design scissor linkages, one of which is based on scissor elements, and the other is based on assembling loops. This study presents a systematic classification of scissor linkages as assemblies of rhombus, kite, dart, parallelogram and anti-parallelogram loops using frieze patterns and long-short diagonal connections. After the loops are replicated along a curve as a pattern, the linkages are obtained by selection of proper common link sections for adjacent loops. The resulting linkages are analyzed for their motions and they are classified as realizing scaling deployable, angular deployable or transformable motion. Some of the linkages obtained are novel. Totally 10 scalable deployable, 1 angular deployable and 8 transformable scissor linkages are listed. Designers in architecture and engineering can use this list of linkages as a library of scissor linkage topologies.Article Design, Prototyping and Tests of a Rollable Ramp for Temporary Use(Springer, 2021) Doğan Kumtepe, Elvan; Kiper, GökhanPortable ramps, used generally by wheelchair users, offer temporary solution to increase accessibility and mobility. Preferably these ramps should be compact and lightweight for ease of handling and storage. Different types of portable ramps in the market that are used by wheelchair users are generally made of aluminum and require several improvements, especially in terms of lightweight and compactness. Based on wheelchair users’ inclinations a compact and lightweight rollable ramp is designed in this study. A parametric model of the links of the ramp are derived and the rolled geometry is optimized using convex hull and smallest enclosing circle algorithms. The side bars of the links are designed and manufactured from aluminum and the load-bearing panels are manufactured from sandwich composite structures with honeycomb core. Strength calculations are performed analytically and also with finite-element analysis. After the design is finalized, a prototype is manufactured. The designed ramp is 15.4% more compact and has 18.9% less weight compared to the best rival product available in the market. Load tests and functional tests are performed with voluntary wheelchair users. Several positive feedbacks are received from the participants about the ramp being practical, easy to use and store, lightweight, advantage of the anti-slip surface.Article Citation - WoS: 15Citation - Scopus: 18Achieving Query Performance in the Cloud Via a Cost-Effective Data Replication Strategy(Springer, 2021) Tos, Uras; Mokadem, Riad; Hameurlain, Abdelkader; Ayav, TolgaMeeting performance expectations of tenants without sacrificing economic benefit is a tough challenge for cloud providers. We propose a data replication strategy to simultaneously satisfy both the performance and provider profit. Response time of database queries is estimated with the consideration of parallel execution. If the estimated response time is not acceptable, bottlenecks are identified in the query plan. Data replication is realized to resolve the bottlenecks. Data placement is heuristically performed in a way to satisfy query response times at a minimal cost for the provider. We demonstrate the validity of our strategy in a performance evaluation study.Article Citation - WoS: 11Citation - Scopus: 12Phytohormone Release by Three Isolated Lichen Mycobionts and the Effects of Indole-3 Acid on Their Compatible Photobionts(Springer, 2020) Candotto Carniel, Fabio; Muggia, Lucia; Ametrano, Claudio Gennaro; Kranner, Ilse; Çimen, Tuğçe; Pichler, Gregor; Stoggl, Wolfgang; Trippel, DanielaEvidence is emerging that phytohormones represent key inter-kingdom signalling compounds supporting chemical communication between plants, fungi and bacteria. The roles of phytohormones for the lichen symbiosis are poorly understood, particularly in the process of lichenization, i.e. the key events which lead free-living microalgae and fungi to recognize each other, make physical contact and start developing a lichen thallus. Here, we studied cellular and extracellularly released phytohormones in three lichen mycobionts, Cladonia grayi, Xanthoria parietina and Tephromela atra, grown on solid medium, and the effects of indole-3-acetic acid (IAA) on their respective photobionts, Asterochloris glomerata, Trebouxia decolorans, Trebouxia sp. Using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) we found that mycobionts produced IAA, salicylic acid (SA) and jasmonic acid (JA). IAA represented the most abundant phytohormone produced and released by all mycobionts, whereas SA was released by X. parietina and T. atra, and JA was released by C. grayi only. With a half-life of 5.2 days, IAA degraded exponentially in solid BBM in dim light. When IAA was exogenously offered to the mycobionts' compatible photobionts at "physiological" concentrations (as released by their respective mycobionts and accumulated in the medium over seven days), the photobionts' water contents increased up to 4.4%. Treatment with IAA had no effects on the maximum quantum yield of photosystem II, dry mass, and the contents of photosynthetic pigments and alpha-tocopherol of the photobionts. The data presented may be useful for designing studies aimed at elucidating the roles of phytohormones in lichens.