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Publication Metadata only 16.4: the optics of an autostereoscopic multiview display(SID, 2010) Baghsiahi, Hadi; Selviah, David R.; Willman, Eero; Fernández, Anibal; Day, Sally E.; Surman, Phil A.; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Erden, Erdem; Chellappan, Kishore Velichappattu; Ürey, Hakan; Master Student; Researcher; Faculty Member; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 8579An autostereoscopic head-tracked back projection display that uses an RGB laser illumination source and a fast light engine is described. Images are horizontally scanned columns controlled by a spatial light modulator that directs two or more images in the directions of the apposite viewers 'eyes.Publication Metadata only 300 GHz broadband transceiver design for low-THz band wireless communications in indoor internet of things(Ieee, 2017) N/A; Department of Electrical and Electronics Engineering; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Khalid, Nabil; Abbasi, Naveed Ahmed; Akan, Özgür Barış; Researcher; PhD Student; Faculty Member; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 6647This paper presents the architectural design of a 300 GHz transceiver system that can be used to explore the high speed communication opportunities offered by the Terahertz (THz) band for advanced applications of Internet-of-Things (IoT). We use low cost industry ready components to prepare a fully customizable THz band communication system that provides a bandwidth of 20 GHz that is easily extendable up to 40 GHz. Component parameters arc carefully observed and used in simulations to predict the system performance while the compatibility of different components is ensured to produce a reliable design. Our results show that the receiver provides a conversion gain of 51 dB with a noise figure (NE) of 9.56 dB to achieve a data rate of 90.31 Gbps at an operation range of 2 meters, which is suitable for high speed indoor IoT nodes. The flexible design of the transceiver provides groundwork for further research efforts in 5G IoT applications and pushing boundaries of throughputs to the order of terabits per second (Tbps).Item Metadata only 3D bioprinted organ-on-chips(John Wiley and Sons Inc, 2023) 0000-0003-4604-217X; 0009-0004-1518-6706; 0000-0002-5295-5701; 0000-0001-8888-6106; Mustafaoglu, Nur; Zhang, Yu Shrike; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Taşoğlu, Savaş; Birtek, Mehmet Tuğrul; Sarabi, Misagh Rezapour; Dabbagh, Sajjad Rahmani; Faculty Member; PhD Student; PhD Student; PhD Student; Koç Üniversitesi İş Bankası Yapay Zeka Uygulama ve Araştırma Merkezi (KUIS AI)/ Koç University İş Bank Artificial Intelligence Center (KUIS AI); KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; 291971; N/A; N/A; N/AOrgan-on-a-chip (OOC) platforms recapitulate human in vivo-like conditions more realistically compared to many animal models and conventional two-dimensional cell cultures. OOC setups benefit from continuous perfusion of cell cultures through microfluidic channels, which promotes cell viability and activities. Moreover, microfluidic chips allow the integration of biosensors for real-time monitoring and analysis of cell interactions and responses to administered drugs. Three-dimensional (3D) bioprinting enables the fabrication of multicell OOC platforms with sophisticated 3D structures that more closely mimic human tissues. 3D-bioprinted OOC platforms are promising tools for understanding the functions of organs, disruptive influences of diseases on organ functionality, and screening the efficacy as well as toxicity of drugs on organs. Here, common 3D bioprinting techniques, advantages, and limitations of each method are reviewed. Additionally, recent advances, applications, and potentials of 3D-bioprinted OOC platforms for emulating various human organs are presented. Last, current challenges and future perspectives of OOC platforms are discussed. © 2022 The Authors. Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.Publication Metadata only 3D coffee stains(Royal Soc Chemistry, 2017) N/A; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Department of Molecular Biology and Genetics; Department of Chemistry; Department of Chemistry; Department of Electrical and Electronics Engineering; Department of Molecular Biology and Genetics; Department of Chemistry; Department of Electrical and Electronics Engineering; Doğru-Yüksel, Itır Bakış; Söz, Çağla Koşak; Press, Daniel Aaron; Melikov, Rustamzhon; Begar, Efe; Çonkar, Deniz; Karalar, Elif Nur Fırat; Yılgör, Emel; Yılgör, İskender; Nizamoğlu, Sedat; PhD Student; PhD Student; Researcher; PhD Student; PhD Student; PhD Student; PhD Student; Faculty Member; Researcher; Faculty Member; Faculty Member; N/A; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); N/A; N/A; N/A; N/A; N/A; N/A; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Sciences; College of Sciences; College of Sciences; College of Engineering; N/A; N/A; N/A; N/A; N/A; N/A; 206349; N/A; 24181; 130295When a liquid droplet (e.g., coffee, wine, etc.) is splattered on a surface, the droplet dries in a ring-shaped stain. This widely observed pattern in everyday life occurs due to the phenomenon known as a coffee stain (or coffee ring) effect. While the droplet dries, the capillary flow moves and deposits the particles toward the pinned edges, which shows a 2D ring-like structure. Here we demonstrate the transition from a 2D to a 3D coffee stain that has a well-defined and hollow sphere-like structure, when the substrate surface is switched from hydrophilic to superhydrophobic. The 3D stain formation starts with the evaporation of the pinned aqueous colloidal droplet placed on a superhydrophobic surface that facilitates the particle flow towards the liquid-air interface. This leads to spherical skin formation and a cavity in the droplet. Afterwards the water loss in the cavity due to pervaporation leads to bubble nucleation and growth, until complete evaporation of the solvent. In addition to the superhydrophobicity of the surface, the concentration of the solution also has a significant effect on 3D coffee stain formation. Advantageously, 3D coffee stain formation in a pendant droplet configuration enables the construction of all-protein lasers by integrating silk fibroin with fluorescent proteins. No tools, components and/or human intervention are needed after the construction process is initiated; therefore, 3D coffee-stains hold promise for building self-assembled and functional 3D constructs and devices from colloidal solutions.Publication Metadata only 3D video tools(Springer Science and Business Media Deutschland GmbH, 2019) Dumic, Emil; Boussetta, Khaled; da Silva Cruz, Luis A.; Dagiuklas, Tasos; Liotta, Antonio; Politis, Ilias; Qiao, Yuansong; Torres Vega, Maria; Ye, Yuhang; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; College of Engineering; 26207This chapter presents an overview of different tools used in research and engineering of 3D video delivery systems. These include software tools for 3D video compression and streaming, 3D video players, and their interfaces. Other types of tools widely used in research studies and development of new networking solutions, such as network simulators, emulators, testbeds, and network analysis tools are also covered. In addition, several 3D video evaluation tools, which have been specifically designed for testing and evaluation of 3D video sequences subject to network impairments, are further described. The chapter also presents several examples of recent works that have been carried out based on one or more simulation, emulation, test, and/or evaluation tools in research studies or innovative solutions for relevant problems affecting 3D multimedia delivery.Publication Metadata only 3DTV and 3D video communications(Assoc Computing Machinery, 2010) Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; College of Engineering; 26207With wider availability of low cost multi-view cameras, 3D displays, and broadband communication options, 3D media is destined to move from the movie theater to home and mobile platforms. In the near term, popular 3D media will most likely be in the form of stereoscopic video with associated spatial audio. Recent trials indicate that consumers are willing to watch stereoscopic 3D media on their TVs, laptops, and mobile phones. While it is possible to broadcast 3D stereoscopic media (two-views) over digital TV platforms today, streaming over IP will provide a more flexible approach for distribution of 3D media to users with different connection bandwidths and different 3D displays. In the intermediate term, free-view 3D video and 3DTV with multi-view capture are next steps in the evolution of 3D media technology. Recent free-view 3D auto-stereoscopic displays can display multi-view video, ranging from 5 to 200 views. Transmission of multi-view 3D media, via broadcast or on-demand, to end users with varying 3D display terminals and bandwidths is one of the biggest challenges to realize the vision of bringing 3D media experience to the home and mobile devices. This requires flexible rate-scalable, resolution-scalable, view-scalable, view-selective, and packet-loss resilient transport methods. In this talk, first I will briefly review the state of the art in 3D video formats, coding methods, IP streaming protocols and streaming architectures. We will then take a look at 3D video transport options. There are two main platforms for 3D broadcasting: standard digital television (DTV) platforms and the IP platform. I will summarize the approach of European project DIOMEDES which is developing novel methods for adaptive streaming of multi-view video over a combination of DVB and IP platforms. I will also summarize additional challenges associated with real-time interactive 3D video communications for applications such as 3D telepresence. Finally, open research challenges for the long term vision of haptic video and holographic 3D video will be presented.Publication Metadata only 48.4: Beam forming for a laser based auto-stereoscopic multi-viewer display(Blackwell Publishing Ltd, 2011) Baghsiahi, Hadi; Selviah, David R.; Willman, Eero; Fernández, Anibal; Day, Sally E.; Surman, Phil A.; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Akşit, Kaan; Ölçer, Selim; Mostafazadeh, Aref; Erden, Erdem; Chellappan, Kishore Velichappattu; Ürey, Hakan; PhD Student; Other; N/A; Other; N/A; Faculty Member; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; N/A; College of Engineering; N/A; N/A; N/A; N/A; N/A; 8579An auto-stereoscopic back projection display using a RGB multiemitter laser illumination source and micro-optics to provide a wider view is described. The laser optical properties and the speckle due to the optical system configuration and its diffusers are characterised. © 2011 SID.Publication Metadata only A 35--μm pitch IR thermo-mechanical MEMS sensor with AC-coupled optical readout(IEEE-Inst Electrical Electronics Engineers Inc, 2015) Ferhanoğlu, Onur; Torun, Hamdi; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Adiyan, Ulaş; Çivitçi, Fehmi; Ürey, Hakan; PhD Student; Researcher; Faculty Member; Graduate School of Sciences and Engineering; College of Sciences; College of Engineering; N/A; 194282; 8579A thermo-mechanical MEMS detector with 35-mu m pixel pitch is designed, fabricated, and characterized. This fabricated design has one of the smallest pixel sizes among the IR thermo-mechanical MEMS sensors in the literature. The working principle of the MEMS detector is based on the bimaterial effect that creates a deflection when exposed to IR radiation in the 812-mu m waveband. The nanometer level out of plane mechanical motion is observed in response to IR heating of the pixel, which is detected by a diffraction grating-based optical readout. Performance of MEMS sensor arrays with optical readout have been limited by a large DC bias that accompanies a small AC signal. We developed a novel optical setup to reduce the DC term and the related noise using an AC-coupled detection scheme. Detailed noise characterization of the pixel and the readout system is reported in this paper. The noise equivalent temperature difference of our detector is measured as 216 mK using f/0.86 lens with the AC-coupled optical readout. Finally, we obtained a thermal image using a single MEMS pixel combined with a scanning configuration. Despite the reduced pixel size, the measured noise levels are comparable to the state-of-the-art thermo-mechanical IR sensors.Item Metadata only A Bayesian perspective for determinant minimization based robust structured matrix factorization(Institute of Electrical and Electronics Engineers Inc., 2023) 0000-0003-0876-2897; Tatli, Gokcan; Department of Electrical and Electronics Engineering; Erdoğan, Alper Tunga; Faculty Member; Koç Üniversitesi İş Bankası Yapay Zeka Uygulama ve Araştırma Merkezi (KUIS AI)/ Koç University İş Bank Artificial Intelligence Center (KUIS AI); College of Engineering; 41624We introduce a Bayesian perspective for the structured matrix factorization problem. The proposed framework provides a probabilistic interpretation for existing geometric methods based on determinant minimization. We model input data vectors as linear transformations of latent vectors drawn from a distribution uniform over a particular domain reflecting structural assumptions, such as the probability simplex in Nonnegative Matrix Factorization and polytopes in Polytopic Matrix Factorization. We represent the rows of the linear transformation matrix as vectors generated independently from a normal distribution whose covariance matrix is inverse Wishart distributed. We show that the corresponding maximum a posteriori estimation problem boils down to the robust determinant minimization approach for structured matrix factorization, providing insights about parameter selections and potential algorithmic extensions.Item Metadata only A biofeedback based virtual reality game for pediatric population (BioVirtualPed): a feasibility trial(Elsevier Inc., 2024) 0000-0002-2031-7967; 0000-0003-1999-9179; 0000-0002-0083-7754; 0000-0002-7544-5974; N/A; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Ürey, Hakan; Semerci, Remziye; Umaç, Eyşan Hanzade; Gürsoy, Beren Semiz; Dinçer, Betül; Sayın, Ata; Faculty Member; Faculty Member; PhD Student; Faculty Member; Undergraduate Student; Undergraduate Student; College of Engineering; School of Nursing; Graduate School of Health Sciences; College of Engineering; College of Engineering; College of Engineering; 8579; 216754; N/A; 332403; N/A; N/AObjective: This trial aims to assess the acceptability, feasibility, and safety of BioVirtualPed, a biofeedback-based virtual reality (VR) game designed to reduce pain, anxiety, and fear in children undergoing medical procedures. Methods: An Oculus Quest 2 headset was used in the VR experience, respiratory data was captured using an ADXL354 accelerometer, and these data were integrated into the game with ArdunioUno software. The sample of this study consisted of 15 pediatric oncology patients aged 6 to 12 years between July and August 2023. BioVirtualPed's acceptability, feasibility, and safety were evaluated through child and expert feedback, alongside metrics including the System Usability Scale, Wong-Baker Pain Rating Scale, Child Fear Scale, Child Anxiety Scale-Status, Satisfaction Scoring, and various feasibility and safety parameters. Results: Regarding the acceptability, the expert evaluation showed a mean score of 122.5 ± 3.53, indicating high usability for the system. All children provided positive feedback, and both children and their mothers reported high satisfaction with using BioVirtualPed. The BioVirtualPed was feasible for reducing children's pain, fear, and anxiety levels. All the children complied with the game, and no one withdrew from the trial. BioVirtualPed did not cause symptoms of dizziness, vomiting, or nausea in children and was found to be safe for children. Conclusion: The findings showed that BioVirtualPed meets the following criteria: feasibility, user satisfaction, acceptability, and safety. It is a valuable tool to improve children's experience undergoing port catheter needle insertion procedures. Implication for Nursing Practice: Integration of VR interventions with BioVirtualPed into routine nursing care practices has the potential to effectively manage the pain, anxiety, and fear experienced by children undergoing medical procedures. The safety, feasibility, and acceptability results are promising for further research and integration into pediatric healthcare practice. © 2024 Elsevier Inc.