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Yayın İlişkisel estetik bağlamında sanat katılımcısının ışıkla diyaloğu(Işık Üniversitesi, 2024-03-01) Yetik, Zelal Şükran; Kara Sarıoğlu, Didem; Işık Üniversitesi, Lisansüstü Eğitim Enstitüsü, Sanat Kuramı ve Eleştiri Yüksek Lisans Programıİlişkisel estetik, Nicolas Bourriaud’nun 1990’lı yılların sanatının doğru değerlendirilmesi için önerdiği bir form kuramıdır. İlişkisel form kuramı yeni ilişkilerin oluşmasına zemin hazırlayarak teknolojinin insanlar arası ilişkiler üzerindeki olumsuz etkisine dikkat çekmiştir. Bourriaud’nun düşüncesine göre; Teknoloji, insanın yerini alan uygulamalarla, kurulan ilişkileri yok etmektedir. Sanat aracılığıyla ilişkisellik yeniden oluşturulmaktadır. İlişkiselliğin oluşması için sanat izleyicisinin sanatın icrasında etkin olması gerekmektedir. Bu doğrultuda sanat izleyicisinin katılımcıya geçiş süreci önem taşımaktadır. Modern sanat ve sonrasında ortaya çıkan sanat hareketleri izleyicinin sanat katılımcısı olmasına olanak tanımıştır. Etkileşimli sanat çalışmalarında katılımcı sanat eserine katkıda bulunarak, sanatın icrasında etkin bir role sahip olmaktadır. Katılımcı, ilişkisel forma sahip sanat çalışmalarında ilişkiselliği ortaya çıkaracaktır. İlişkisel estetik bağlamında değerlendirilen çalışmaların, teknolojik olmayan medyumlar içereceği düşünülebilir. Teknolojiyle birlikte insan hayatına giren yapay ışık, dijital ekranlar nedeniyle insanların her gün maruz kaldıkları bir unsurdur ve olumsuz etkilerinin yanı sıra insan hayatını kolaylaştırmaktadır. Bu tez araştırmasında yapay ışık unsuru ilişkisel bağlamda değerlendirilerek, ilişkiselliğin oluşmasında teknoloji ürünü olan bir medyum olarak kullanılması incelenmiştir. Doğal ve yapay ışık medyumlarının, insanla ilişkisi ve ilişkisel estetik bağlamında ışığın katılımcı ile diyaloğu araştırılmıştır. Yapay ışık medyumu ve etkilerinin yeni ilişki alanları oluşturduğuna dikkat çekilmesi amaçlanmıştır.Yayın Müze sergileme vitrinleri ve mağaza vitrinlerininn aydınlatma tekniği kuralları açısından karşılaştırılması(Işık Üniversitesi, 2018-05-29) Akgün, Buram; Kılıç Sirel, Hülya; Işık Üniversitesi, Sosyal Bilimler Enstitüsü, İç Mimarlık Yüksek Lisans ProgramıSergileme vitrinlerinde görsel konfor, nesnelerin doğru algılanabilmesini sağlayan önemli bir unsurdur. Bu doğrultuda günümüzde vitrin aydınlatması, giderek önem kazanan bir konu haline gelmiştir. Bu çalışma kapsamında, müze ve mağaza sergileme vitrinlerindeki aydınlatma ilkeleri karşılaştırılarak sergi nesnelerinin ışığa duyarlılıklarına göre elde edilmesi gereken maksimum aydınlık düzeyleri, ışıklılık sorunları ve doğru görme koşullarının sağlanabilmesi için alınacak önemleler araştırılmıştır. Ayrıca sergileme hacmi içersindeki aydınlatma sistemleri ve nesnelerin algılanmasına etkisi üzerinde durulmuştur. Araştırma kapsamında aydınlatma kavramı, doğal ve yapay aydınlatma konuları ele alınıp, aydınlatmanın mekân kavramı ile ilişkisi üzerinde durulmuştur. Sergileme mekânlarında aydınlatma tasarımı, aydınlatmanın işleyişine ve kişilerin görsel algısı üzerindeki etkisi ayrıca ele alınmıştır. Çalışmanın ilk aşamasında aydınlatma, aydınlatma tekniği ve ışık kaynakları başlığı altında, doğal günışığı ve yapay aydınlatma sistemleri ve ışıklıklar incelenmiştir. Çalışmanın ikinci bölümünde müze ve mağaza vitrinleri incelenmiş, aydınlatma düzenleri değerlendirilmiştir. Bu kapsamda sergileme düzeni sabit tutularak araştırmanın koşulları sınırlandırılmıştır. Çalışmanın son aşamasında aydınlatmanın, tasarımla bir bütün olarak düşünülmesi ve bütün süreçlerde bu ilkeyle hareket edilmesi gerektiğinden yola çıkılarak, müze sergileme vitrinleri ile mağaza vitrinleri arasındaki benzerlikler ve farklılıklar ortaya konulmuş olup sergileme düzeni ile aydınlatma düzeninin birlikte tasarlanmasının önemi vurgulanmıştır.Yayın Channel modelling for indoor visible light communications(Royal Society Publishing, 2020-04-17) Miramirkhani, Farshad; Uysal, MuratVisible light communication (VLC) allows the dual use of light-emitting diodes (LEDs) for wireless communication purposes in addition to their primary purpose of illumination. As in any other communication system, realistic channel modelling is a key for VLC system design, analysis and testing. In this paper, we present a comprehensive survey of indoor VLC channel models. In order to set the background, we start with an overview of infrared (IR) channel modelling, which has received much attention in the past, and highlight the differences between visible and IR optical bands. In the light of these, we present a comparative discussion of existing VLC channel modelling studies and point out the relevant advantages and disadvantages. Then, we provide a detailed description of a site-specific channel modelling approach based on non-sequential ray tracing that precisely captures the optical propagation characteristics of a given indoor environment. We further present channel models for representative deployment scenarios developed through this approach that were adopted by the Institute of Electrical and Electronics Engineering (IEEE) as reference channel models. Finally, we consider mobile VLC scenarios and investigate the effect of receiver location and rotation for a mobile indoor user. This article is part of the theme issue ‘Optical wireless communication’.Yayın Channel modeling and characterization for VLC-based medical body sensor networks: trends and challenges(IEEE, 2021-11-15) Dönmez, Barış; Mitra, Rangeet; Miramirkhani, FarshadOptical Wireless Communication (OWC) refers to transmission in unguided propagation media through the use of optical carriers, i.e., visible, Infrared (IR), and Ultraviolet (UV) bands. In this paper, we focus on indoor Visible Light Communication (VLC)-based Medical Body Sensor Networks (MBSNs) which allow the Light Emitting Diodes (LEDs) to communicate between on-body sensors/subdermal implants and on-body central hubs/monitoring devices while also serving as a luminaire. Since the Quality-of-Service (QoS) of the communication systems depends heavily on realistic channel modeling and characterization, this paper aims at presenting an up-to-date survey of works on channel modeling activities for MBSNs. The first part reviews existing IR-based MBSNs channel models based on which VLC channel models are derived. The second part of this review provides details on existing VLC-based MBSNs channel models according to the mobility of the MBSNs on the patient’s body. We also present a realistic channel modeling approach called site-specific ray tracing that considers the skin tissue for the MBSNs channel modeling for realistic hospital scenarios.Yayın A path loss model for link budget analysis of indoor visible light communications(Istanbul Univ-Cerrahpasa, 2021-05) Miramirkhani, FarshadIn the context of beyond 5G indoor communication systems, visible light communications (VLC) has emerged as a viable supplement for existing radio frequency based systems and as an enabler for high data rate communications. However, the existing indoor VLC systems are limited by detrimental outages caused by fluctuations in the VLC channel gain because of user mobility. In this study, we proposed a tractable path loss model for indoor VLC that reflects the effect of room size and coating material of surfaces. We performed an extensive advanced ray tracing simulation to obtain the channel impulse responses within a room and presented a path loss model as a function of distance, room size, and coating material through curve fitting. In addition, path loss parameters such as the path loss exponent and the standard deviation of the shadowing component were determined. The simulation results indicate that path loss is a linear function of distance, path loss exponent is a function of room size and coating material, and shadowing follows a log normal distribution.Yayın Reordering of polystyrene gel due to multiple swelling in organic vapor fast transient fluorescence technique study(Elsevier Science SA, 2006-07-31) Erdoğan, Matem; Pekcan, Mehmet ÖnderReordering of disc-shaped polystyrene (PS) gels due to multiple swelling, under organic vapor was studied by using Fast Transient Fluorescence (FTRF) technique. Disc-sbaped polystyrene gels were prepared by free radical copolymerization (FRC) of styrene (S) with ethylene glycol dimethacrylate (EGDM) as a crosslinker. Pyrene (P) was introduced as a fluorescence probe during polymerization. Swelling experiments were performed by using P doped PS gels under chloroform vapor. After each swelling step, gels were left to dry in an oven at 30 degrees C for consecutive reswelling experiments. Decay curves of P were measured and pyrene lifetimes, tau, were determined. It was observed that tau values decreased as swelling recycles were repeated. It was observed that after the fifth swelling step, two different regimes appeared in the swelling processes in PS gels. Swelling time constant, tau(c), and cooperative diffusion coefficients, D-c were determined by using Li-Tanaka equation for each swelling step in both regimes. It was observed that D-c values decreased up to tenth swelling step and then remained unchanged in both regimes.Yayın Channel modeling and characterization for VLC-based MBSNs impaired by 3D user mobility(IEEE, 2021-11-27) Dönmez, Barış; Miramirkhani, FarshadThis paper focuses on channel modeling and characterization of indoor visible light communication (VLC)-based medical body sensor networks (MBSNs) which establish links between light-emitting diodes (LEDs) and MBSNs nodes couple with photodetectors (PDs) placed on the shoulder (D1), wrist (D2), and ankle (D3) of the mobile user who walks over random trajectories in 3D scenarios of ICU ward and family type patient room. We adopt non-sequential ray-tracing to obtain channel impulse responses (CIRs) and channel characteristics over random trajectories. Based on simulation results, it is observed that channel DC gains exhibit sinusoidal behaviour for D1 and D2 except for D3 (i.e., due to the number of diffuse rays received at D3), as the user approaches and moves away from the luminaries. It is also revealed that a flat fading channel can be modeled if a data rate lower than 7.03 Mbit/s, i.e., sufficient for MBSNs applications, is chosen.Yayın Enabling 5G indoor services for residential environment using VLC technology(Elsevier B.V., 2022-03-10) Miramirkhani, Farshad; Karbalayghareh, Mehdi; Zeydan, Engin; Mitra, RangeetVisible light communication (VLC) has emerged as a viable complement to traditional radio frequency (RF) based systems and as an enabler for high data rate communications for beyond-5G (B5G) indoor communication systems. In particular, the emergence of new B5G-based applications with quality of service (QoS) requirements and massive connectivity has recently led to research on the required service-levels and the development of improved physical (PHY) layer methods. As part of recent VLC standards development activities, the IEEE has formed the 802.11bb “Light Communications (LC) for Wireless Local Area Networking” standardization group. This paper investigates the network requirements of 5G indoor services such as virtual reality (VR) and high-definition (HD) video for residential environments using VLC. In this paper, we consider such typical VLC scenarios with additional impairments such as light-emitting diode (LED) nonlinearity and imperfect channel feedback, and propose hyperparameter-free mitigation techniques using Reproducing Kernel Hilbert Space (RKHS) methods. In this context, we also propose using a direct current biased optical orthogonal frequency division multiplexing (DCO-OFDM)-based adaptive VLC transmission method that uses precomputed bit error rate (BER) expressions for these RKHS-based detection methods and performs adaptive BER-based modulation-order switching. Simulations of channel impulse responses (CIRs) show that the adaptive transmission method provides significantly improved error rate performance, which makes it promising for high data rate VLC-based 5G indoor services.Yayın Eastern Anatolia Observatory (DAG): the status in 2022, towards the first light(SPIE, 2022) Yeşilyaprak, Cahit; Keskin, Onur; Jolissaint, LaurentEast Anatolian Observatory's DAG telescope, with its 4m diameter primary mirror and VIS/IR observation capability, Eastern Anatolian Observatory's 4m diameter class DAG telescope, with VIS/IR observation capability, will be located on the Konakll-Karaya summit at an altitude of 3170 m, near the city of Erzurum, Turkey. DAG contains both active optics (aO) and adaptive optics (AO) systems. With the enclosure assembly nearly done, and the dummy mirror integration including the M1 cell integration performed at the end of 2021; DAG telescope's AIV is planned to take place by the end of May/2022 and the Provisional Acceptance by November/2022. DAG is equipped with an in-flange derotator-KORAY (K-mirror Optical RelAY) that will direct the light to the seeing limited Nasmyth platform containing TROIA (TuRkish adaptive Optics system for Infrared Astronomy). The scientific instruments that DAG will receive in 2022, are but not limited to, a stellar coronagraph and a 30"NIR diffraction limited camera. In his paper, a global status update and expected optical performance characteristics will be presented.Yayın ViLDAR-Visible light sensing-based speed estimation using vehicle headlamps(IEEE, 2019-11) Abuella, Hisham; Miramirkhani, Farshad; Ekin, Sabit; Uysal, Murat; Ahmed, SamirThe introduction of light emitting diodes (LED) in automotive exterior lighting systems provides opportunities to develop viable alternatives to conventional communication and sensing technologies. Most of the advanced driver-assist and autonomous vehicle technologies are based on Radio Detection and Ranging (RADAR) or Light Detection and Ranging (LiDAR) systems that use radio frequency or laser signals, respectively. While reliable and real-time information on vehicle speeds is critical for traffic operations management and autonomous vehicles safety, RADAR or LiDAR systems have some deficiencies especially in curved road scenarios where the incidence angle is rapidly varying. In this paper, we propose a novel speed estimation system so-called the Visible Light Detection and Ranging (ViLDAR) that builds upon sensing visible light variation of the vehicle's headlamp. We determine the accuracy of the proposed speed estimator in straight and curved road scenarios. We further present how the algorithm design parameters and the channel noise level affect the speed estimation accuracy. For wide incidence angles, the simulation results show that the ViLDAR outperforms RADAR/LiDAR systems in both straight and curved road scenarios.
