WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/4465

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Citation - WoS: 3
Citation - Scopus: 5
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; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
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 - WoS: 3
Citation - Scopus: 4
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; International Relations; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
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 - WoS: 5
Citation - Scopus: 6
(3+3+2) Warped-Like Product Manifolds With Spin(7) Holonomy
(Elsevier Science Bv, 2011) Uğuz, Selman; Bilge, Ayşe Hümeyra; Industrial Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
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 - WoS: 10
Citation - Scopus: 15
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; Electrical-Electronics Engineering; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
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 - WoS: 2
Citation - Scopus: 3
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; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
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
6-Point Tripled Ashkin-Teller Global Phase Diagrams in Two and Three Dimensions
(Elsevier, 2025) Zeynioglu, Deniz Ipek; Berker, A. Nihat
The tripled Ashkin-Teller model including 6-point interactions is solved in d = 2 and 3 by renormalization-group theory that is exact on the hierarchical lattice and approximate on the recently first/second-order-transition improved Migdal-Kadanoff procedure. Five different ordered phases occur in the dimensionally distinct global phase diagrams. 16 different phase diagram cross-sections in the 2-point and 4-point interaction space are obtained, with first-and second-order phase transitions, multiple tricritical points and critical endpoints.
Citation - WoS: 4
Citation - Scopus: 6
Abortion Services at Hospitals in Istanbul
(Taylor & Francis Ltd, 2017) O'Neil, Mary Lou; Political Science and International Relations; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
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 - WoS: 1
Citation - Scopus: 1
Accelerated Trends in Tourism Marketing and Tourist Behaviour
(Routledge, 2023) Kozak, Metin; Kozak, Metin; Advertising; 04. Faculty of Communication; 01. Kadir Has University
[No Abstract Available]
Citation - WoS: 1
Citation - Scopus: 2
Acculturation Strategies of International Higher Education Students in Türkiye: the Role of Social Support, Cultural Capital, Self-Esteem, General Trust, and General Self-Efficacy
(Springer, 2025) Ergin-Kocaturk, Hatice; Tekel, Esra; Su, Ahmet; Kocaturk, Metin; Karadag, Engin; 01. Kadir Has University
Understanding the factors influencing acculturation strategies among international students cannot be overstated, as successful adaptation is crucial for academic success and overall well-being. Although extensive research has explored these dynamics in various contexts, a notable gap remains in the literature on international students in T & uuml;rkiye. This study aimed to investigate the effects of social support, cultural and economic capital, self-esteem, general trust, and general self-efficacy on the acculturation strategies of international higher-education students in T & uuml;rkiye. Utilizing data from 3,554 international students, various scales and questionnaires were employed, including the Acculturation Strategies Scale, Cultural Capital Questionnaire, Economic Capital Questionnaire, Self-Esteem Scale, General Confidence Scale, General Self-Efficacy Scale, and Social Support Questionnaire. The collected data were analyzed using correlation and multiple regression analyses. The results revealed significant relationships between the examined factors and acculturation strategies adopted by international students. These findings highlight the crucial roles of social support, cultural capital, and psychological attributes in shaping how international students adapt to new cultural environments. The implications of these results underscore the importance of targeted support programs to enhance international students' acculturation experiences and overall well-being in T & uuml;rkiye's higher education context.
Citation - WoS: 12
Citation - Scopus: 15
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; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
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.
Acoustic Assessment of Four Music Rehearsal Rooms in Accordance With ISO23591 Standard
(Elsevier Sci Ltd, 2025) Saher, Konca; Ozgencil, Yalin; Khoshkholghi, Solmaz; Interior Architecture and Environmental Design; 06. Faculty of Art and Design; 01. Kadir Has University
Optimizing rehearsal room acoustics is crucial for musicians to perceive sound, pitch, and frequency variations. Since the introduction of the international standard ISO 23591 Acoustic quality criteria for music rehearsal rooms and spaces, research in the field of music rehearsal rooms has significantly intensified. However, relatively few have adopted an approach that integrates both objective measurements and subjective user evaluations, particularly in rehearsal rooms for quiet-category instruments. Therefore, this study aimed to assess and improve the acoustical conditions of four Turkish rehearsal rooms for quiet-category instruments using measurements, simulations, and musician surveys. A survey conducted in the first phase revealed that musicians rated the efficiency, satisfaction, and frequency balance of four rehearsal rooms as bad to fair. Efficiency of rehearsals showed a strong correlation with frequency balance (R2 = 0.72 for low-to-mid; R2 = 0.76 for high-to-mid). Strong correlations (R2 = 0.93) were found between calculated and perceived low-to-mid frequency balance, while high-to-mid frequency balance showed weaker correlations (R2 = 0.36), suggesting possible sensitivity to low-frequency issues; though this did not consistently align with user satisfaction, indicating that additional perceptual factors play a role. Acoustic measurements show that existing reverberation time (RTmid) values for all rooms fall outside recommended limits. The measured rehearsal rooms were modeled, calibrated, and 36 acoustic models were developed with three alternative designs to improve acoustics within recommended limits. Then musicians from these rooms assessed 36 acoustic models through listening tests based on auralizations. Listening tests showed a preference for models with RTmid values within the recommended range, aligning subjective and objective assessments. After the RTmid value, effect of low-to-mid frequency balance was important in the choice of rooms for musicians.
Citation - WoS: 7
Citation - Scopus: 6
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.; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
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 - WoS: 7
The Act of Killing an Interview With Joshua Oppenheimer
(CINEASTE, 2013) Behlil, Melis; Oppenheimer, Joshua; Radio, Television and Cinema; 04. Faculty of Communication; 01. Kadir Has University
[Abstract Not Available]
Active Citizenship in Europe Practices and Demands in the Eu, Italy, Turkey, and the Uk Conclusion
(Palgrave, 2017) Bee, Cristiano; 01. Kadir Has University
[Abstract Not Available]
Active Citizenship: Policy Developments at the Eu Level
(Palgrave, 2017) Bee, Cristiano; 01. Kadir Has University
[Abstract Not Available]
Citation - WoS: 6
Citation - Scopus: 10
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; Management Information Systems; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
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 - WoS: 3
Citation - Scopus: 2
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; Mechatronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
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.
Addressing Social Vulnerabilities Resulting From Low-Carbon Energy Transition Policies in EU-27 Countries: A Systematic Survey of the Literature
(Pergamon-Elsevier Science Ltd, 2026) Albulut, Koray; 01. Kadir Has University
Low-carbon transition research has experienced exponential growth in recent years, driven by the urgent need to mitigate climate change and achieve sustainability goals. The disruption of traditional industries, increased energy costs, and changes in land use are inevitable consequences of the low-carbon turn, often adversely impacting the least equipped to handle it. Vulnerable groups often face the greatest risks from climate change and the side effects of the policies designed to combat it. This study conducts a systematic literature review following the PRISMA 2020 guidelines, covering publications from the Web of Science and Scopus databases. Data were extracted into spreadsheets for descriptive analytics, and trends in publication years, countries, and policy tools were visualized with Python-generated heatmaps and summary tables. The findings reveal that despite best efforts to unburden vulnerable groups, many unaddressed concerns remain in the European 27 countries, where one might least expect them. The analysis highlights how one-size-fits-all policies ignore regional and social differences, disproportionately burdening vulnerable groups while favoring wealthier segments through subsidies and incentives. The mixed effectiveness of countermeasures-such as social tariffs, subsidies, and the Just Transition Mechanism-highlights ongoing challenges, including misrecognition, elite capture, and institutional constraints, while also underscoring notable successes like participatory community energy projects and locally tailored retrofitting initiatives. This research underscores the necessity of moving beyond uniform solutions, advocating for locally sensitive, equitable approaches that address affected communities' diverse needs and aspirations while ensuring social and environmental justice in the transition to a lowcarbon economy.
Citation - WoS: 1
Citation - Scopus: 1
Adults' Recollection of the Earliest Memories: Early Parental Elaboration Mediated the Link Between Attachment and Remembering
(Springer, 2022) Oener, Sezin; Guelgoez, Sami; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Social interactions are a major factor in organizing the earliest experiences in the memory system. In the current study, we tested the role of parental reminiscing on the relationship between parental attachment and recollection of earliest memories. The present study focused mainly on possible mediating properties of parental elaboration between the relationship of attachment and the recall of the earliest memories. We found a full mediation pattern, showing that high parental avoidance was associated with less parental elaboration, which was then linked to the earliest memories coming from a later age and poor recollection of these memories. On the other hand, although parental anxiety was related to the earliest memories coming from a later age and rich recollection of the earliest memories, the degree of parental elaboration was not found as a mediator. Findings are discussed in line with the role of the early relational and communicative input on adults' recollections of early events.
Citation - WoS: 23
Citation - Scopus: 35
An advanced Grey Wolf Optimization Algorithm and its application to planning problem in smart grids
(Springer, 2022) Ahmadi, Bahman; Younesi, Soheil; Ceylan, Oguzhan; Ozdemir, Aydogan; Management Information Systems; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Due to the complex mathematical structures of the models in engineering, heuristic methods which do not require derivative are developed. This paper improves recently developed Grey Wolf Optimization Algorithm by extending it with three new features: namely presenting a new formulation for evaluating the positions of search agents, applying mirroring distance to the variables violating the limits, and proposing a dynamic decision approach for each agent either in exploration or exploitation phases. The performance of Advanced Grey Wolf Optimization (AGWO) method is tested using several optimization test functions and compared to several heuristic algorithms. Moreover, a planning problem in smart grids is solved by considering different objective functions using 33 and 141 bus distribution test systems. From the numerical simulation results, we observe that, AGWO is able to find the best results compared to other methods from 10 and 9 out of 13 test functions for 30 and 60 variables, respectively. Similar to this, it finds best function values for 5 out of 10 fixed number of variable test functions. Also, the result of the CEC-C06 2019 benchmark functions shows that AGWO outperforms 8 for optimization problems from 10. In power distribution system planning problem, better objective function values were determined by using AGWO, resulting a better voltage profile, less losses, and less emission costs compared to solutions obtained by Grey Wolf Optimization (GWO) and Particle Swarm Optimization (PSO) algorithms.

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