Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.khas.edu.tr/handle/20.500.12469/1248

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Citation Count: 1
A 130 nm CMOS Receiver for Visible Light Communication
(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Ksack, Rifat; Yagan, Muhammed Yaser; Uysal, Murat; Pusane, Ali Emre; Baykas, Tuncer; Dundar, Gunhan; Yalcinkaya, Arda Deniz
Visible light communication (VLC) is an emerging technology that has been gaining attention over the last few years. Transmission of data at higher rates in a VLC system is mainly limited by the modulation bandwidth of the employed LED. To alleviate this limitation, equalization is frequently employed. This is usually achieved by either using discrete circuit elements or in digital form. In this paper, we present a power-efficient VLC receiver as a system-on-chip, implemented in 130 nm CMOS technology. The proposed receiver supports LEDs with different bandwidths thanks to the switchable equalizer. We tested the proposed receiver using phosphorescent white LEDs with different bandwidths on an experimental VLC link. For each tested LED, around 20 fold improvement in data rate was achieved compared to the original bandwidth of the LED. For the LED with a modulation bandwidth of 1.6 MHz, data rates of 32 Mbps and 50 Mbps at a BER of 10(-2) were obtained at a distance of 2 meters without and with a blue filter, respectively.
Citation Count: 0
18 - Turkey
(Cambridge University Press, 2020) Diner,C.
Each of these chapters contains a case study of a couple from the relevant country. Each includes a description of the everyday life of the couple with respect to the division of housework and childcare, a recounting of the history of their relationship and how it became equal, a discussion of how they balance paid work and family, and an analysis of the factors that facilitate their equality. Those factors include their conviction in gender equality, their rejection of essentialist beliefs, their familism, and their socialization in their families of origin. By showing how and why they undo gender, these couples provide lessons on how equality at home can be achieved. © Cambridge University Press 2020
Citation Count: 0
The 1921 Constitution and Beyond: Any Inspiration After 100 Years?
(Istanbul University Press, 2022) Arat, N.; Topukçu, A.
The 1921 Constitution has mostly been considered as a unique piece of legal document in Turkish Legal History with regard to the time it was written, the conditions under it was created, the necessity it touched and the era it changed. The 1921 Constitution had been assessed by scholars, bureaucrats, politicians and lawyers in different times from distinct perspectives. It has got special attention lately as regards to the discussions on constitution-making processes. Even after 100 years, many of its features inspire today's constitutional discussions as the 1921 Constitution touches even today's sociological, political and legal needs. In this context, this paper aims to assess the 1921 Constitution first by pointing out the unique features; then, gives try to answer a question posed whether the 1921 Constitution is a constitution itself, or not. This trial is done under the double constitution period discussions and by pulling out the deficiencies of the 1921 Constitution. Subsequently, the box of inspirational touches of the 1921 Constitution to 100 years beyond is opened. In that sense, it has been found that the understanding of sovereignty that brings it down to its origin “earth/humankind”, the idea of local democracy and the vision on fundamental rights and freedoms that open the door to modern understanding of rights on this part of the world, could be drawn/inherited for today's constitutional making processes. © 2022 Istanbul University Press. All Rights Reserved.
Citation Count: 1
A 2020 Vision for the Black Sea Region: the Commission on the Black Sea Proposes
(Routledge Journals Taylor & Francis Ltd, 2010) Aydın, Mustafa; Triantaphyllou, Dimitrios
The Black Sea region is coming into its own although it is at times a contested and dangerous neighbourhood. Despite heightened interest in the region its real priorities and needs are still being largely ignored by insiders and outsiders alike. What is needed are regional solutions for regional problems. The authors present the key findings and recommendations of the Commission on the Black Sea a civil society initiative comprising a number of current and former policy-makers scholars and practitioners both from within the region and from outside with the purpose of contributing to a joint vision and a common strategy for the Black Sea region by developing new knowledge in areas of key concern.
Citation Count: 0
2nd tourism and hospitality networking conference | RESNET’22
(Routledge, 2023) Serra, J.
[No abstract available]
Citation Count: 5
(3+3+2) Warped-Like Product Manifolds With Spin(7) Holonomy
(Elsevier Science Bv, 2011) Uğuz, Selman; Bilge, Ayşe Hümeyra
We consider a generalization of eight-dimensional multiply warped product manifolds as a special warped product by allowing the fiber metric to be non-block diagonal. We define this special warped product as a (3 + 3 + 2) warped-like manifold of the form M = F x B. where the base B is a two-dimensional Riemannian manifold and the fibre F is of the form F = F-1 x F-2 where the F-i(i = 1 2) are Riemannian 3-manifolds. We prove that the connection on M is completely determined by the requirement that the Bonan 4-form given in the work of Yasui and Ootsuka [Y. Yasui and T. Ootsuka Spin(7) holonomy manifold and superconnection Class. Quantum Gravity 18(2001)807-816] be closed. Assuming that the F-i are complete connected and simply connected it follows that they are isometric to S-3 with constant curvature k > 0 and the Yasui-Ootsuka solution is unique in the class of (3 + 3 + 2) warped-like product metrics admitting a specific Spin(7) structure. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Citation Count: 4
3d Indoor Positioning With Spatial Modulation for Visible Light Communications
(Elsevier, 2023) Sen, Umit; Yesilirmak, Yalin Evrim; Bayman, Irem Ozgur; Arsan, Taner; Panayırcı, Erdal; Stevens, Nobby
In this paper, a novel three-dimensional (3D) indoor visible light positioning (VLP) algorithm is proposed based on the spatial modulation (SM) and its error performance assessed as compared to the conventional received signal strength (RSS)-based 3D VLP systems. As contrasted to the traditional VLP system, the proposed SM-based 3D VLP system first estimates the optical channel gain between the transmitting light-emitting diodes (LEDs) and the two photo detectors (PDs) attached to the user by a pilot-based channel estimation technique. Then, unknown 3D positions of the receiver are determined by the trilateration algorithm with distances computed from the estimates of the channel gains. Consequently, the 3D VLP system achieves an interference -free transmission with increased spectral efficiency and without the need for a demultiplexing process at the receiving end. The algorithm's performance is evaluated regarding positioning error by applying the SM over four LEDs and the number of pilots selected as a function of the environmental signal-to-noise ratios (SNRs). The computer simulation results show that the positioning errors are obtained in an order of magnitude smaller than RSS-based techniques in an indoor industrial environment. This is mainly because the distances involved in determining the 3D positions can be determined more precisely by the pilot-aided channel estimation method without creating any data rate problem in transmission due to the higher spectral efficiency of the SM.
Citation Count: 1
3d-Printed Actuator-Based Beam-Steering Approach for Improved Physical Layer Security in Visible Light Communication
(Optica Publishing Group, 2022) Erdem, Mehmet Can; Gurcuoglu, Oguz; Panayırcı, Erdal; Kurt, Gunes Karabulut; Ferhanoglu, Onur
In this study, we present the design, manufacture, and implementation of a 3D-printed lens scanner-based beam steering for use in visible light communication (VLC) applications. The 5 cm x 5 cm scanner is designed for low-cost 3D printing with fused deposition modeling using polylactic acid. Scanning is facilitated through electromagnetic actuation of the lens frame, carrying a conventional 25 mm lens, from two nearly orthogonal directions. The serpentine spring that connects the lens frame to the external frame is tailored to offer similar spring constants in the directions of actuation and has minimal (<1.5 mm) sag due to the mass of the lens. The manufactured actuator was integrated on a miniaturized VLC test bed (70 cm x 40 cm x 40 cm). Using the test bed, we characterized the applied voltage versus beam displacement behavior of the actuator in the lateral plane and demonstrated beam steering on amoving target with face-recognition feedback. The proposed scheme was targeted to offer an improved security measure in VLC through tracking the legitimate receiver (i.e., via face recognition) and uses the feedback to steer the focused light onto the targeted device. The joint use of focusing and steering features allows for the legitimate receiver to roam within the room while enjoying the improved secrecy due to the focused light. We calculate the secrecy capacity for the demonstrated approach, which compares favorably with a number of jamming, spatial modulation, and beam-forming counterparts. The presented actuator can be used with larger room dimensions, yet upscaling to larger illumination units will require the use of a lens having smaller focus to address a larger total steering angle. (C) 2022 Optica Publishing Group
Citation Count: 3
Abortion Services at Hospitals in Istanbul
(Taylor & Francis Ltd, 2017) O'Neil, Mary Lou
Objective: Despite the existence of a liberal law on abortion in Turkey there is growing evidence that actually securing an abortion in Istanbul may prove difficult. This study aimed to determine whether or not state hospitals and private hospitals that accept state health insurance in Istanbul are providing abortion services and for what indications. Method: Between October and December 2015 a mystery patient telephone survey of 154 hospitals 43 public and 111 private in Istanbul was conducted. Results: 14% of the state hospitals in Istanbul perform abortions without restriction as to reason provided in the current law while 60% provide the service if there is a medical necessity. A quarter of state hospitals in Istanbul do not provide abortion services at all. 48.6% of private hospitals that accept the state health insurance also provide for abortion without restriction while 10% do not provide abortion services under any circumstances. Key conclusions: State and private hospitals in Istanbul are not providing abortion services to the full extent allowed under the law. The low numbers of state hospitals offering abortions without restriction indicates a de facto privatization of the service. This same trend is also visible in many private hospitals partnering with the state that do not provide abortion care. While many women may choose a private provider the lack of provision of abortion care at state hospitals and those private hospitals working with the state leaves women little option but to purchase these services from private providers at some times subtantial costs.
Citation Count: 0
The Abyme of the Shallow
(Taylor & Francis, 2014) Tüzün, Defne
[Abstract Not Available]
Citation Count: 0
Accelerated Trends in Tourism Marketing and Tourist Behaviour
(Routledge, 2023) Kozak, Metin; Kozak, Metin
[No Abstract Available]
Citation Count: 2
Accented Essays: Documentary as Artistic Practice in Contemporary Audiovisual Works From Turkey
(Routledge, 2019) Akçalı,E.
This article looks at the use of documentary filmmaking in contemporary artistic practices in Turkey, specifically focusing on three works that adopt a first-person, subjective viewpoint: Didem Pekün’s Of Dice and Men (2016), Şener Özmen’s How to Tell of Peace to a Living Dove? (2015), and Aykan Safoğlu’s Off-White Tulips (2013). Made by artists in transition, these films tackle themes of belonging and identity through stylistic choices proper to essayistic filmmaking, which allow these works to be regarded as accented essays. The personal questions raised through the aesthetics they employ become relevant to collective issues of culture, history, and memory, offering an alternative understanding of the social context, which was largely affected by the political events during the period in which they were made. © 2019, © 2019 Critical Arts.
Citation Count: 11
Accurate Refinement of Docked Protein Complexes Using Evolutionary Information and Deep Learning
(Imperıal College Press, 2016) Akbal-Delibas, Bahar; Farhoodi, Roshanak; Pomplun, Marc; Haspel, Nurit
One of the major challenges for protein docking methods is to accurately discriminate native-like structures from false positives. Docking methods are often inaccurate and the results have to be refined and re-ranked to obtain native-like complexes and remove outliers. In a previous work we introduced AccuRefiner a machine learning based tool for refining protein-protein complexes. Given a docked complex the refinement tool produces a small set of refined versions of the input complex with lower root-mean-square-deviation (RMSD) of atomic positions with respect to the native structure. The method employs a unique ranking tool that accurately predicts the RMSD of docked complexes with respect to the native structure. In this work we use a deep learning network with a similar set of features and five layers. We show that a properly trained deep learning network can accurately predict the RMSD of a docked complex with 1.40 angstrom error margin on average by approximating the complex relationship between a wide set of scoring function terms and the RMSD of a docked structure. The network was trained on 35000 unbound docking complexes generated by RosettaDock. We tested our method on 25 different putative docked complexes produced also by RosettaDock for five proteins that were not included in the training data. The results demonstrate that the high accuracy of the ranking tool enables AccuRefiner to consistently choose the refinement candidates with lower RMSD values compared to the coarsely docked input structures.
Citation Count: 0
Acoustic Design Guidelines for Adults With Intellectual Disability
(European Acoustics Association EAA, 2014) Şaher, Konca; Nijs, Lau; Hordijk, Truus
This paper concentrates on the acoustic design aspects of the living rooms in institutions for adults with intellectually disability. In the living rooms for adults with ID there is even a higher stress on the acoustics since they are more dependent on the acoustical environment compared to normal population. Moreover prevalence of hearing impairment among adults with ID is around 30% and in most cases it is not even recognised. Therefore the rooms for adults with ID need to be designed by taking into account the requirements of the hearing impaired. They need more favourable room acoustics to improve their communication and participation. This paper investigates three main themes: 1) Investigation of impact of building design tools on acoustical quality parameters and determination of most appropriate acoustical quality indicator that translates best into architectural practice for living rooms for adults with ID. 2) Investigation of the relation between user satisfaction and absorption amount in rooms for adults with ID by listening tests prepared from auralizations. 3) Development of architectural/acoustical design guidelines to provide optimal absorption amount for living rooms for adults with ID.
Citation Count: 0
ACOUSTIC TRANSFORMATION OF ROCK-CUT CAVES INTO PERFORMANCE SPACES
(European Acoustics Association, EAA, 2023) Aslan,A.; Saher,K.; Tozoglu,A.E.
Cappadocia Region in Turkey is a center of attention as a tourism destination with its rock-cut caves, some of which are being used as performance spaces for concerts, festivals and local entertainment activities. However, these spaces are not fully investigated for their acoustic performance before being transformed into performance venues. This paper reports on the findings of an initial survey which presents a systematic mapping of the rock-cut caves used as performance spaces to locate, explore and document a sample of structures scattered in this historic district. A typological classification based on volume, size, type of tuff rock material and historical original use has been proposed and an acoustic analysis of some selected rock-cut caves has been carried out. The acoustic analysis included reverberation time calculations and simulations based on apparent volume, and tuff stone absorption characteristics, which were studied by other researchers in the area. © 2023 Aslan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation Count: 5
The acquisition and use of relative clauses in Turkish-learning children's conversational interactions: a cross-linguistic approach
(Cambridge University Press, 2019) Uzundağ, Berna A.; Küntay, Aylin C.
Using a cross-linguistic approach, we investigated Turkish-speaking children's acquisition and use of relative clauses (RCs) by examining longitudinal child-caregiver interactions and cross-sectional peer conversations. Longitudinal data were collected from 8 children between the ages of 8 and 36 months. Peer conversational corpus came from 78 children aged between 43 and 64 months. Children produced RCs later than in English (Diessel, 2004) and Mandarin (Chen & Shirai, 2015), and demonstrated increasing semantic and structural complexity with age. Despite the morphosyntactic difficulty of object RCs, and prior experimental findings showing a subject RC advantage, preschool-aged children produced object RCs, which were highly frequent in child-directed speech, as frequently as subject RCs. Object RCs in spontaneous speech were semantically less demanding (with pronominal subjects and inanimate head nouns) than the stimuli used in prior experiments. Results suggest that multiple factors such as input frequency and morphosyntactic and semantic difficulty affect the acquisition patterns.
Citation Count: 0
Actors of Rural Innovation: Bamboo Craft Initiatives From Northeast India
(Nova Science Publishers, Inc., 2020) Bayraktaroğlu, S.
The purpose of the chapter is to identify the nature of innovation practiced in rural organizations. Accordingly, this study focuses on the processes of innovation in bamboo craft initiatives in rural territories of Northeast India. The study examines the craft economy in the region and involvement of main actors in the process from making to marketing via tracing the impact of a decades-old successful development intervention. Based on the neo-endogenous development theory and rural capital framework, the chapter investigates distinct business models emerged through a multi-actor intervention. Identification of actors and their roles in the network reveals the four phases of the process of rural innovation. © 2020 Nova Science Publishers, Inc. All rights reserved.
Citation Count: 5
Acute Myeloblastic Leukemia Achieving Complete Remission With Amifostine Alone
(2002) Öztürk, Ahmet Kutlu; Orhan, Bülent; Türken, Orhan; Etiz, Durmuş; Yaylacı, Mustafa; Üskent, Necdet
Amifostine, a phosphorylated thiol-amine, is known as a cytoprotective agent especially for cisplatin containing chemotherapies. Apart from the cytoprotective role, Amifostine could also be used in the treatment of hematologic malignancies such as myelodysplastic syndrome (MDS) and acute myeloblastic leukemia (AML), as a treatment option or for potentiating the effects of cytotoxic agents. We tried to use Amifostine in a patient with AML, which did not respond to conventional cytotoxic chemotherapy and aimed to publish the results. The patient was a 77-year-old male patient, he was diagnosed as AML by peripheral blood smear and bone marrow aspiration. Treatment commenced with low dose cytosine arabinoside (Ara-C) but the therapy should have ceased due to patient intolerance. The patient refused further therapy and he was offered to have Amifostine treatment. Amifostine was administered 200 mg/m2 three times a week, with ciprofloxacin, pentoxifyllin and dexamethasone. Dramatic response was obtained after 8 weeks of administration. Blast rate was reduced from 35 to 7% in bone marrow aspiration; pancytopenia was restored to normal levels. This remission was maintained through 8 more weeks. Amifostine treatment was restarted after he relapsed but this time he did not respond to the treatment and died of gastrointestinal bleeding on the 8th week of treatment.
Citation Count: 4
An Adaptive Affinity Matrix Optimization for Locality Preserving Projection Via Heuristic Methods for Hyperspectral Image Analysis
(IEEE-Inst Electrıcal Electronıcs Engıneers Inc, 2019) Taşkın, Gülşen; Ceylan, Oğuzhan
Locality preserving projection (LPP) has been often used as a dimensionality reduction tool for hyperspectral image analysis especially in the context of classification since it provides a projection matrix for embedding test samples to low dimensional space. However, the performance of LPP heavily depends on the optimization of two parameters of the graph affinity matrix: k-nearest neighbor and heat kernel width, when one considers an isotropic kernel. These two parameters might be optimally chosen simply based on a grid search. In case of using a generalized heat kernel where each feature is separately weighted by a kernel width, the number of parameters that need to be optimized is related to the number of features of the dataset, which might not be very easy to tune. Therefore, in this article, we propose to use heuristic methods, including genetic algorithm (GA), harmony search (HS), and particle swarm optimization (PSO), to explore the effects of the heat kernel parameters aiming to analyze the embedding quality of LPP's projection in terms of various aspects, including 1-NN classification accuracy, locality preserving power, and quality of the graph affinity matrix. The results obtained with the experiments on three hyperspectral datasets show that HS performs better than GA and PSO in optimizing the parameters of the affinity matrix, and the generalized heat kernel achieves better performance than the isotropic kernel. Additionally, a feature selection application is performed by using the kernel width of the generalized heat kernel for each heuristic method. The results show that very promising results are obtained in comparison with the state-of-the-art feature selection methods.
Citation Count: 0
Adaptive Sampling Noise Mitigation Technique for Feedback-Based Quantum Algorithms
(Springer international Publishing Ag, 2024) Rahman, Salahuddin Abdul; Clausen, Henrik Glavind; Karabacak, Ozkan; Wisniewski, Rafal
Inspired by Lyapunov control techniques for quantum systems, feedback-based quantum algorithms have recently been proposed as alternatives to variational quantum algorithms for solving quadratic unconstrained binary optimization problems. These algorithms update the circuit parameters layer-wise through feedback from measuring the qubits in the previous layer to estimate expectations of certain observables. Therefore, the number of samples directly affects the algorithm's performance and may even cause divergence. In this work, we propose an adaptive technique to mitigate the sampling noise by adopting a switching control law in the design of the feedback-based algorithm. The proposed technique can lead to better performance and convergence properties. We show the robustness of our technique against sampling noise through an application for the maximum clique problem.

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