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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/6
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Publication Open Access An historical geographic information system for Ottoman Studies. The c. 1907 Ottoman Census and Armenian Settlement in Istanbul(Peeters Online Journals, 2020) Ohanian, Daniel; Başkurt, Z. Mehmet; Department of History; Kabadayı, Mustafa Erdem; Faculty Member; Department of History; College of Social Sciences and Humanities; 33267The purpose of this article is to announce the publication of a partial transcription of the c. 1907 Ottoman census that relates to 24,000 Apostolic Armenian Istanbulites and of a historical geographic information system (HGIS), or interactive map, that shows where these individuals lived. Within this framework, the authors first present their argument that an unidentified, microfilmed population register housed in New York is the most substantial portion of this census currently available to researchers. In the second part of their article, they introduce HGISes as tools for the digital humanities and describe the process of creating one.Publication Open Access Dynamic accommodation measurement using Purkinje reflections and ML algorithms(Society of Photo-optical Instrumentation Engineers (SPIE), 2023) Department of Electrical and Electronics Engineering; N/A; Aygün, Uğur; Şahin, Afsun; Ürey, Hakan; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); College of Engineering; School of Medicine; N/A; N/A; N/A; 171267; 8579We developed a prototype device for dynamic gaze and accommodation measurements based on 4 Purkinje reflections (PR) suitable for use in AR and ophthalmology applications. PR1&2 and PR3&4 are used for accurate gaze and accommodation measurements, respectively. Our eye-model was developed in Zemax and matches the experiments well. Our model predicts the accommodation from 25cm to infinity (<4 diopters) with better than 0,25D accuracy. We performed repeatability tests and obtained accurate gaze and accommodation estimations using 15 subjects. We are generating a large synthetic data set using physically accurate models and machine learning algorithms.Publication Open Access Granulomatosis with Poliangiitis (GPA)(Hacettepe Tıp Fakültesi, 2021) Kanıtez, Nilüfer Alpay; Şentürk, Begüm Güler; Faculty Member; Researcher; School of Medicine; 239432; 327593NAPublication Open Access Comparison of anxiety and depression scores between patients with and without ST-segment elevation acute coronary syndrome(Bayçınar Tıbbi Yayıncılık ve Reklam Hizmetleri, 2021) Palabıyık, Mert; Sinan, Ümit Yaşar; Çetinarslan, Özge; Oktay, Veysel; Özkan, Alev; Faculty Member; School of Medicine; Koç University Hospital; 12695Objectives: we aimed to investigate the difference between anxiety and depression status among ST-segment elevation acute coronary syndrome (STE-ACS) and non-ST-segment elevation ACS (NSTE-ACS) patients. Patients and methods: this study is a cross-sectional study that included 165 patients (132 males, 33 females; mean age: 59.3±10.5 years; range, 48 to 71 years) who were hospitalized with a final diagnosis of ACS (both NSTE-ACS and STE-ACS) between January 2019 and April 2019. The Hospital Anxiety and Depression Scale (HADS) was used to measure the patients’ anxiety and depression status. Results: according to current European Society of Cardiology (ESC) guidelines, 91 (55.2%) patients were classified as NSTE-ACS and 74 (44.8%) patients as STE-ACS. According to the HADS scores, 33 (20%) of the total study population had anxiety diagnoses, and 28 (17%) of them had depression . While the mean depression score was 4.8±4.9 for NSTE-ACS patients, it was 4.6±4.3 for STE-ACS patients (p=0.723). The mean anxiety score was 6.1±5.1 for NSTE-ACS patients and 5.6±4.5 for STE-ACS patients (p=0.546), which was similar between the two groups. Conclusion: although NSTE-ACS and STE-ACS are two different entities of ACS spectrum, patients hospitalized with these diagnoses have similar anxiety and depression scores.Publication Open Access Computational selection of high-performing covalent organic frameworks for adsorption and membrane-based CO2 /H2 separation(American Chemical Society (ACS), 2020) Department of Chemical and Biological Engineering; Keskin, Seda; Altıntaş, Çiğdem; Harman, Hilal Dağlar; Aksu, Gökhan Önder; Researcher; Department of Chemical and Biological Engineering; College of Engineering; Graduate School of Sciences and Engineering; 40548; N/A; N/A; N/ACovalent organic frameworks (COFs) have high potential in gas separation technologies because of their porous structures, large surface areas, and good stabilities. The number of synthesized COFs already reached several hundreds, but only a handful of materials were tested as adsorbents and/or membranes. We used a high-throughput computational screening approach to uncover adsorption-based and membrane-based CO2/H2 separation potentials of 288 COFs, representing the highest number of experimentally synthesized COFs studied to date for precombustion CO2 capture. Grand canonical Monte Carlo (GCMC) simulations were performed to assess CO2/H2 mixture separation performances of COFs for five different cyclic adsorption processes: pressure swing adsorption, vacuum swing adsorption, temperature swing adsorption (TSA), pressure−temperature swing adsorption (PTSA), and vacuum−temperature swing adsorption (VTSA). The results showed that many COFs outperform traditional zeolites in terms of CO2 selectivities and working capacities and PTSA is the best process leading to the highest adsorbent performance scores. Combining GCMC and molecular dynamics (MD) simulations, CO2 and H2 permeabilities and selectivities of COF membranes were calculated. The majority of COF membranes surpass Robeson’s upper bound because of their higher H2 permeabilities compared to polymers, indicating that the usage of COFs has enormous potential to replace current materials in membrane-based H2/CO2 separation processes. Performance analysis based on the structural properties showed that COFs with narrow pores [the largest cavity diameter (LCD) < 15 Å] and low porosities (ϕ < 0.75) are the top adsorbents for selective separation of CO2 from H2, whereas materials with large pores (LCD > 20 Å) and high porosities (ϕ > 0.85) are generally the best COF membranes for selective separation of H2 from CO2. These results will help to speed up the engineering of new COFs with desired structural properties to achieve high-performance CO2/H2 separations.Publication Open Access Wearable multi-color RAPD screening device(Society of Photo-optical Instrumentation Engineers (SPIE), 2023) Department of Electrical and Electronics Engineering; Aygün, Uğur; Şahin, Afsun; Ürey, Hakan; Hasanreisoğlu, Murat; Kavaklı, Koray; Küçüködük, Abdullah; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; School of Medicine; Koç University Hospital; N/A; N/A; 171267; 8579; 182001; N/A; N/A; N/A; N/A; N/AIn this work, we developed a wearable, head-mounted device that automatically calculates the precise Relative Afferent Pupillary Defect (RAPD) value of a patient. The device consists of two RGB LEDs, two infrared cameras, and one microcontroller. In the RAPD test, the parameters like LED on-off durations, brightness level, and color of the light can be controlled by the user. Upon data acquisition, a computational unit processes the data, calculates the RAPD score and visualizes the test results with a user-friendly interface. Multiprocessing methods used on GUI to optimize the processing pipeline. We have shown that our head-worn instrument is easy to use, fast, and suitable for early-diagnostics and screening purposes for various neurological conditions such as RAPD, glaucoma, asymmetric glaucoma, and anisocoria.Publication Open Access Cluster index modulation for mmWave communication systems(Frontiers, 2022) Koç, Asil; Le-Ngoc, Tho; Department of Electrical and Electronics Engineering; Başar, Ertuğrul; Raeisi, Mahmoud; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; 149116; N/AIn this study, a novel cluster index modulation (CIM) scheme, which is based on indexing the available clusters in the environment, is proposed for future mmWave communication systems. Exploiting the fact that the available clusters in the system are well separated in terms of their angular distribution, we selected the best path for each of them and then performed IM in an algorithmic manner to convey information bits. It is shown that by means of large antenna arrays and analog RF beamforming with the indexed clusters, the destructive effect of inter-beam/cluster interference can be remarkably mitigated. Also, we designed a hybrid beamforming architecture at the transmitter to further reduce the effect of residual inter-beam/cluster interference, where the analog RF beamformer is followed by a digital baseband precoder using the zero-forcing technique. Computer simulations reveal that the proposed scheme can provide better error performance than traditional mmWave communication, and the proposed hybrid architecture outperforms beam index modulation (BIM) for a point-to-point scenario. Semi-analytical derivations and closedform unconditional pairwise error probability (UPEP) expressions are derived for both analog and hybrid architectures, which confirm the validity and superiority of our proposed scheme.Publication Open Access Universal transceivers: opportunities and future directions for the Internet of Everything (IoE)(Frontiers, 2021) Department of Electrical and Electronics Engineering; Kuşcu, Murat; Civaş, Meltem; Çetinkaya, Oktay; Akan, Özgür Barış; Researcher; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; 316349; N/A; N/A; 6647The Internet of Everything (IoE) is a recently introduced information and communication technology (ICT) framework promising for extending the human connectivity to the entire universe, which itself can be regarded as a natural IoE, an interconnected network of everything we perceive. The countless number of opportunities that can be enabled by IoE through a blend of heterogeneous ICT technologies across different scales and environments and a seamless interface with the natural IoE impose several fundamental challenges, such as interoperability, ubiquitous connectivity, energy efficiency, and miniaturization. The key to address these challenges is to advance our communication technology to match the multi-scale, multi-modal, and dynamic features of the natural IoE. To this end, we introduce a new communication device concept, namely the universal IoE transceiver, that encompasses transceiver architectures that are characterized by multi-modality in communication (with modalities such as molecular, RF/THz, optical and acoustic) and in energy harvesting (with modalities such as mechanical, solar, biochemical), modularity, tunability, and scalability. Focusing on these fundamental traits, we provide an overview of the opportunities that can be opened up by micro/nanoscale universal transceiver architectures towards realizing the IoE applications. We also discuss the most pressing challenges in implementing such transceivers and briefly review the open research directions. Our discussion is particularly focused on the opportunities and challenges pertaining to the IoE physical layer, which can enable the efficient and effective design of higher-level techniques. We believe that such universal transceivers can pave the way for seamless connection and communication with the universe at a deeper level and pioneer the construction of the forthcoming IoE landscape.Publication Open Access Postpartum sexuality: a study from Turkish women’s perpectives(Era's Lucknow Medical College _ Hospital, 2022) Gölbaşı, Zehra; Turgut, Nilüfer; Kaya, Didem; Eroğlu, Kafiye; Faculty Member; School of Nursing; 6061This study is a descriptive study conducted to determine women's views on sexuality in the postpartum period. This study was conducted in the postpartum clinic of a state hospital in a city in Turkey. The study sample included 355 women with 95% confidence and 5% margin of error. The data was collected through questionnaire which were conducted face to face interviews. Chi-square test was used in statistical analysis. The average age of participant women is 26.31 (SD=5.54). The 51.3% of women agreed that “it is a sin to have sexual intercourse within 40 days following the childbirth”. There is no significant difference between primipara and multipara women in the sense of agreement frequency of this statement (p>0.05). On the other hand, the 46.8% of women agreed with the statement that “Resuming sexual intercourses after birth would be difficult” and 46.5% agreed “Sexual intercourse after birth would be painful”. There was a statistically significant difference in the acceptance rate of these statements between multiparous and primiparous women (p<0.05). According to these results, it is recommended to address the issue of postpartum sexuality within the scope of both prenatal and postnatal care services.Publication Open Access 3D-printed contact lenses: challenges towards translation and commercialization(Future Medicine, 2022) Yetişen, Ali K.; Department of Mechanical Engineering; Taşoğlu, Savaş; Özdalgıç, Berin; Faculty Member; PhD Student; Department of Mechanical Engineering; KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); College of Engineering; Graduate School of Sciences and Engineering; 291971; 323683NA