Scopus İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/1248

Browse

Now showing 1 - 20 of 3136

Citation - WoS: 22
Citation - Scopus: 32
A Quality-of-Service-Aware Service Composition Method in the Internet of Things Using a Multi-Objective Fuzzy-Based Hybrid Algorithm
(Mdpi, 2023) Hamzei, Marzieh; Khandagh, Saeed; Navimipour, Nima Jafari
The Internet of Things (IoT) represents a cutting-edge technical domain, encompassing billions of intelligent objects capable of bridging the physical and virtual worlds across various locations. IoT services are responsible for delivering essential functionalities. In this dynamic and interconnected IoT landscape, providing high-quality services is paramount to enhancing user experiences and optimizing system efficiency. Service composition techniques come into play to address user requests in IoT applications, allowing various IoT services to collaborate seamlessly. Considering the resource limitations of IoT devices, they often leverage cloud infrastructures to overcome technological constraints, benefiting from unlimited resources and capabilities. Moreover, the emergence of fog computing has gained prominence, facilitating IoT application processing in edge networks closer to IoT sensors and effectively reducing delays inherent in cloud data centers. In this context, our study proposes a cloud-/fog-based service composition for IoT, introducing a novel fuzzy-based hybrid algorithm. This algorithm ingeniously combines Ant Colony Optimization (ACO) and Artificial Bee Colony (ABC) optimization algorithms, taking into account energy consumption and Quality of Service (QoS) factors during the service selection process. By leveraging this fuzzy-based hybrid algorithm, our approach aims to revolutionize service composition in IoT environments by empowering intelligent decision-making capabilities and ensuring optimal user satisfaction. Our experimental results demonstrate the effectiveness of the proposed strategy in successfully fulfilling service composition requests by identifying suitable services. When compared to recently introduced methods, our hybrid approach yields significant benefits. On average, it reduces energy consumption by 17.11%, enhances availability and reliability by 8.27% and 4.52%, respectively, and improves the average cost by 21.56%.
Citation - WoS: 17
Citation - Scopus: 20
In Silico Design of Novel and Highly Selective Lysine-Specific Histone Demethylase Inhibitors
(Scientific Technical Research Council Turkey-Tubitak, 2011) Akdoğan, Ebru Demet; Erman, Burak; Yelekçi, Kemal
Histone lysine-specific demethylase (LSD1) is involved in a wide range of epigenetic processes and plays important roles in gene silencing DNA transcription DNA replication DNA repair and heterochromatin formation. Its active site shows a resemblance to those of 2 homologous enzymes monamine oxidase A and B (MAO-A and MAO-B.) In the present work starting from suitable scaffolds and generating thousands of structures from them 10 potential inhibitors were obtained with structural and physicochemical properties selectively suitable for inhibiting LSD1. iLib Diverse software was used to generate the diverse structures and 3 docking tools CDOCKER GOLD and AutoDock were used to find the most probable potential inhibitor based on its binding affinity. The dispositions of the candidate molecules within the organism were checked by ADMET_PSA_2D (polar surface area) versus ADMET_AlogP98 (the logarithm of the partition coefficient between n-octanol and water) and their suitability is discussed. The LSD1 inhibition activities of the candidates were compared with the properties of trans-2-phenylcyclopropylamine (tranylcypromine) and 2-(4-methoxy-phenyl) cyclopropylamine which are the 2 known inhibitors of LSD1.
Citation - Scopus: 3
Cloud Elearning: Transforming Education Through Cloud Technology: Preliminaries for Generation C
(Academic Conferences Limited, 2012) Oberer, B.; Erkollar, A.
Cloud computing is a buzz word that is also spilling over into the education industry, which enables access to software applications, hardware, data, and computer processing power on the Web, rather than installing software onto one's computer or server. For education, it offers new possibilities to structure and perform learning processes. In this study, the potential impact of cloud computing on education is analyzed, showing what it means for educators and students as well as institutions, and summarized under the heading 'Generation C', where C stands for cloud. The results of the study revealed that cloud computing can be used by educators, institutions, and individual students as well as by jurisdiction to support particular teaching and learning experiences and to organize software availability. Challenges for educators and institutions using cloud computing in teaching could be summarized under the following keywords: interoperability and transferability, terms and conditions, security and privacy issues, backup and perpetuity, denial of service and content issues. On a whole, some implications of using cloud computing need to be kept in mind, good understanding of the applications in use, development of guidelines for use and migration strategies as well as the implementation of risk management could allow educators and institutions to take advantage of cloud computing, in turn offering rich online learning experiences for students.
Citation - WoS: 145
Citation - Scopus: 145
Psychological Correlates of Covid-19 Conspiracy Beliefs and Preventive Measures: Evidence From Turkey
(Springer, 2020) Alper, Sinan; Bayrak, Fatih; Yılmaz, Onurcan
COVID-19 pandemic has led to popular conspiracy theories regarding its origins and widespread concern over the level of compliance with preventive measures. In the current preregistered research, we recruited 1088 Turkish participants and investigated (a) individual differences associated with COVID-19 conspiracy beliefs; (2) whether such conspiracy beliefs are related to the level of preventive measures; and (3) other individual differences that might be related to the preventive measures. Higher faith in intuition, uncertainty avoidance, impulsivity, generic conspiracy beliefs, religiosity, and right-wing ideology, and a lower level of cognitive reflection were associated with a higher level of belief in COVID-19 conspiracy theories. There was no association between COVID-19 conspiracy beliefs and preventive measures while perceived risk was positively and impulsivity negatively correlated with preventive measures. We discuss the implications and directions for future research.
Citation - WoS: 21
Citation - Scopus: 21
Design of Practical Broadband Matching Networks With Lumped Elements
(IEEE-INST Electrical Electronics Engineers Inc, 2013) Şengül, Metin Y.
It is always preferable to use commercially available software tools to design broadband matching networks for microwave communication systems. However for these tools the matching network topology and element values must be selected properly. Therefore in this paper a practical method is presented to generate matching networks with good initial element values. Eventually the performance of the designed matching network is optimized by employing the commercially available computer-aided design (CAD) tools. An example is given to illustrate the utilization of the proposed method. It is shown that the proposed method provides very good initials for CAD tools.
Management Information Systems: the Virtual Team Scorecard (vts)
(2013) Oberer, Birgit; Erkollar, Alptekin
Organizations resisting changes are missing opportunities to grow or to become or remain competitive. Management Information Systems (MIS) used as decision support systems may support organizations in making use of changes in environmental conditions. Nevertheless innovative structures are needed to motivate organizations contributing in change projects. Tn this study a virtual team scorecard which can be used as a management information system enabling requirements analyses for managing virtual teams in organizations and in virtual teams with members of different organizations was developed in two different versions: (a) an intemal VTS and (b) an inter-organizational VTS. The results revealed that the developed virtual team scorecard covers all the main strategic factors from a management perspective and in particular relies on the qualitative factors of the team determines the quality and group dynamics deficits of a team and may provide clues for knowing which factors should receive special attention. Furthermore the developed scorecard can be used for inter-organizational teams and any kind of structured co-operation between organizations.
Are Web Designers Resisting the Inclusion of Social Cues When Creating Website's User Interface?
(IGI Global, 2011) De Kervenoael, Ronan; Bisson, Christophe; Mark Palmer, Mark
Using the resistance literature as an underpinning theoretical framework this chapter analyzes how Web designers through their daily practices (i) adopt recursive adaptive and resisting behavior regarding the inclusion of social cues online and (ii) shape the socio-technical power relationship between designers and other stakeholders. Five vignettes in the form of case studies with expert individual Web designers are used. Findings point out at three types of emerging resistance namely: market driven resistance ideological resistance and functional resistance. In addition a series of propositions are provided linking the various themes. Furthermore the authors suggest that stratification in Web designers' type is occurring and that resistance offers a novel lens to analyze the debate. © 2012 IGI Global.
Citation - Scopus: 3
Stripped and layered fabrication of minimal surface tectonics using parametric algorithms
(Walter de Gruyter GmbH, 2023) Gokmen, S.
This article describes a parametric design and fabrication workflow influenced by Frei Otto's form-finding experiments on soap films. The research investigates minimal surface geometry by combining physical and digital experiments in a computational framework. Operating on mesh topology, various parametric design tools and plug-ins in Rhinoceros/Grasshopper are presented to discuss the translation of minimal surfaces to flat strips suitable for planar fabrication using flexible materials. These tools are tested on a case study to show the automated design and manufacture of double-curved surfaces as double-layered strips running in perpendicular directions that can be affixed at point connections for structural stability. The development of the parametric workflow, material constraints, and stripped fabrication of layers are discussed. © 2023 the author(s), published by De Gruyter.
Citation - WoS: 21
Citation - Scopus: 20
"it Was as If Society Didn't Want a Woman To Get an Abortion": a Qualitative Study in Istanbul Turkey
(Elsevier Science Inc, 2017) MacFarlane, Katrina A.; O'Neil, Mary Lou; Tekdemir, Deniz; Foster, Angel M.
Introduction: In 1983 abortion without restriction as to reason was legalized in Turkey. However at an international conference in 2012 the Prime Minister condemned abortion and announced his intent to draft restrictive abortion legislation. As a result of public outcry and protests the law was not enacted but media reports suggest that barriers to abortion access have since worsened. Objectives: We aimed to conduct a qualitative study exploring women's recent abortion experiences in Istanbul Turkey. Study design: In 2015 we conducted 14 semi-structured in-depth interviews with women aged 18 or older who had obtained abortion care in Istanbul on/after January 1 2009. We employed a multimodal recruitment strategy and analyzed these interviews for content and themes using deductive and inductive techniques. Results: Women reported on a total of 19 abortions. Although abortion care is available in private facilities only one public hospital provides abortion services without restriction as to reason. Women who had multiple abortions in different facility types described quality of care more positively in the private sector. Unmarried women considered their marital status when making the decision to seek an abortion and reported challenges obtaining comprehensive sexual and reproductive health services. All participants were familiar with the Turkish government's antiabortion discourse and believed that this was reflective of an overarching desire to restrict women's rights. Conclusion: Public abortion services in Istanbul are currently limited and private abortion services are accessible but relatively expensive to obtain. Recent antiabortion political rhetoric appears to have negatively impacted access and service quality. Implications: This is the first qualitative study exploring women's experiences obtaining abortion services in Turkey since the proposed abortion restriction in 2012. Further research exploring the experiences of unmarried women and abortion accessibility in other regions of the country is warranted. (C) 2017 Elsevier Inc. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 4
The Availability of Emergency Contraception From Family Health Centers in Turkey
(Elsevier Ireland Ltd, 2022) O'Neil, Mary Lou; Aldanmaz, Bahar; Altuntas, Deniz
Reproductive health care, including contraception, is a fundamental aspect of any public health care system and it is important to reduce barriers to access to all forms of contraception, including emergency contraception. In recent years, the rhetoric of pronatalism in Turkey has come to dominate and raises questions about the availability of reproductive health care services, in particular contraception, from state run facilities. This study aimed to determine the availability of dedicated emergency contraception (EC) from government run Family Health Centers (FHCs) in Turkey. In 2019, a team of trained researchers called a random sample of 583 FHCs located in the largest cities in twelve regions across Turkey asking for dedicated EC. Dedicated EC is largely unavailable from government supported FHCs. Only 6.1% stated that they provided EC while 53.8% stated that it was not available and that they could provide no alternative. A further 28.3% declared that they could provide an alternative to dedicated EC that almost always consisted of oral contraceptives. We found statistically significant variations in response rate and availability among cities as well as the rate of referral to pharmacies. There is little access to EC from government sponsored health clinics designated to provide family planning services, which hinders access to an essential reproductive health care service that should be available to women everywhere.
Citation - WoS: 13
Citation - Scopus: 14
Energy-Saving Behavior of Turkish Women: a Consumer Survey on the Use of Home Appliances
(Sage Publications Ltd, 2017) Ucal, Meltem Şengün
This paper focuses on energy-related attitudes and behaviors of Turkish women who are the main users of electrical home appliances responsible for most household energy consumption. Answers from 1323 female respondents surveyed through a unique questionnaire formed the dataset. The results from analysis of variance show that education has a significant effect on the relationship between energy saving and awareness and attitudes about climate change. Significant differences also exist between education level groups in terms of knowledge of the classification of energy-saving electrical home appliances. Responses to questions related to energy-saving purchasing behaviors are consistently higher for knowledgeable respondents. The paper then uses factor analysis and ordinal logit models to reveal interactions between energy-saving behavior regarding electrical home appliances and several factors namely awareness sensitivity essentials and receptiveness. The identification of these factors can provide useful insights for policy makers that enable them to construct energy-saving policies specifically tailored toward women.
Citation - WoS: 9
Citation - Scopus: 8
Daily and Intraday Herding Within Different Types of Investors in Borsa Istanbul
(Routledge Journals, Taylor & Francis Ltd, 2019) Dalgıç, Nihan; Ekinci, Cumhur; Ersan, Oğuz
This paper aims to explore the daily and intraday herd behavior of various investor groups trading in an emerging equity market, Borsa Istanbul (BIST). We analyze a one-year tick-by-tick order and trade data of BIST 100 Index stocks and document differences in herding behavior of investor groups considering market capitalization, market conditions, and announcements as well as daily and intraday periodicities. We find that nonprofessional investors (brokerage houses and domestic funds) tend to herd on large (small) stocks; their herding behavior mostly exhibits a U shape (an inverse U shape) during the day. All types of investors tend to herd in down markets on a daily basis while this behavior disappears, even inverts intraday.
Citation - WoS: 4
Citation - Scopus: 12
Allocation of Distributed Generators Using Parallel Grey Wolf Optimization
(IEEE, 2021) Younesi, Soheil; Ahmadi, Bahman; Ceylan, Oguzhan; Ozdemir, Aydogan
This paper solves the allocation problem of distributed generators (DGs) in smart grids utilizing a grey wolf optimization (GWO) algorithm. By parallelizing GWO, it presents the impact of using various number of processors on speedup, efficiency. To decrease the computation time required to perform the simulations, different migration rates are applied for different number of processors. Moreover, the accuracy obtained using different number of processors is analyzed. The simulations are performed for a 33-bus distribution test system using MATLAB's parallel computing toolbox. From the simulation results it is observed that parallel GWO can be used as a tool for distribution system optimization.
Citation - WoS: 7
Citation - Scopus: 6
Investigation of Pst-Mwcnt Concentration on Epoxyacrylate Photopolymerization and Conductivity of Polymer Films
(Elsevier Science SA, 2013) Doğruyol, Zekeriya; Temel, Gökhan; Doğruyol, Sevnur Keskin; Pekcan, Önder; Arsu, Nergis
Photopolymerization kinetics and conductivity changes of epoxyacrylate composites for various loading modified PSt-MWCNT weight fractions changing from 0.0025 to 0.2 wt.% were evaluated by performing photo differential scanning calorimetry (photo-DSC) and four point conductivity measurements. 0.2% PSt-MWCNT additive polymeric films had their electrical conductivity boosted by 6% more than non-additive polymeric films. (C) 2012 Elsevier B.V. All rights reserved.
Atmosferik Türbülans Altinda Orbital Açisal Momentum Tabanli Haberleşme Sistemleri Orbital Angular Momentum Based Communication Systems Under Atmospheric Turbulence;
(Institute of Electrical and Electronics Engineers Inc., 2020) Sheikh,A.A.A.; Basaran,M.; Erkucuk,S.
Orbital Angular Momentum (OAM) may be a candidate for future communication systems due to its advantages in terms of high data rates and effective frequency utilization. OAM can provide a solution where a beam is transformed into multiple beams within itself and becomes independent streams of data (pertaining to the principle of orthogonality) to be transferred when properly utilized. However, the free space contains atmospheric turbulence which interferes with the beam propagation of OAM and as a result the photons in the light beam are affected as well as the independence of each OAM mode. Therefore, the data stream suffers crosstalk. In this study, weak and strong atmospheric turbulences and how they affect a variety of OAM modes as they propagate through free space are investigated, and important OAM implementation issues are discussed. © 2020 IEEE.
Citation - WoS: 2
Citation - Scopus: 2
Assessing the Renewable Energy Sources for Sustainable Energy Generation Systems: Interval-Valued Q-Rung Orthopair Fuzzy SWARA-TOPSIS
(Elsevier Ltd, 2026) Faruk Görçün, Ö.F.; Aytekin, A.; Selçuk Korucuk, S.; Tirkolaee, E.B.
Renewable Energy Sources (RESs) help decarbonize power systems, but selecting among them is a challenging decision problem due to multiple, often conflicting, technical, economic, environmental, and health-related criteria. Consequently, numerous studies in the literature have attempted to address this decision-making issue using objective, subjective, and fuzzy decision-making procedures. However, there are still unaddressed research gaps in the literature, particularly regarding the explicit modeling of expert hesitation and ambiguity in real-world RES selection cases. The current study develops a decision-making model based on Step-wise Weight Assessment Ratio Analysis (SWARA) and Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) methods integrated with Interval-Valued q-Rung Orthopair Fuzzy Sets (IV-q-ROFSs) to fill these gaps. Unlike previous studies that have predominantly applied conventional fuzzy MCDM techniques, our model introduces the first integration of IV-q-ROFS into RES selection. This novelty enables a more accurate representation of expert hesitation and uncertainty. The study is applied to a real industrial case in Turkey, where six RES alternatives are evaluated across 43 criteria by five senior experts under the supervision of a three-member professionals’ board. Furthermore, the structured robustness check and systematic literature mapping ensure that the proposed approach is methodologically robust and practically relevant for policymakers and energy planners. The application results of the developed model demonstrate that the estimated energy production potential of the RES and the effects of carcinogens generated from utilizing these energy sources are the critical factors influencing the selection of the most appropriate RESs. Solar energy ranked first among the alternatives. The applicability and validity of the developed model are examined by a comprehensive robustness check consisting of tests of sensitivity, comparison, and resilience to the rank reversal problem. Overall, the study provides (i) a novel methodological framework integrating IV-q-ROFS with SWARA and TOPSIS, (ii) empirical evidence from a comprehensive real-world RES selection case, and (iii) policy-relevant insights into the drivers of renewable energy adoption. © 2025 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Citation - WoS: 26
Citation - Scopus: 26
Network Structural Origin of Instabilities in Large Complex Systems
(Amer Assoc Advancement Science, 2022) Duan, Chao; Nishikawa, Takashi; Eroglu, Deniz; Motter, Adilson E.
A central issue in the study of large complex network systems, such as power grids, financial networks, and ecological systems, is to understand their response to dynamical perturbations. Recent studies recognize that many real networks show nonnormality and that nonnormality can give rise to reactivity-the capacity of a linearly stable system to amplify its response to perturbations, oftentimes exciting nonlinear instabilities. Here, we identify network structural properties underlying the pervasiveness of nonnormality and reactivity in real directed networks, which we establish using the most extensive dataset of such networks studied in this context to date. The identified properties are imbalances between incoming and outgoing network links and paths at each node. On the basis of this characterization, we develop a theory that quantitatively predicts nonnormality and reactivity and explains the observed pervasiveness. We suggest that these results can be used to design, upgrade, control, and manage networks to avoid or promote network instabilities.
The political economy of Turkey in the last two centuries
(Taylor and Francis Inc., 2021) Selçuk, B.; Öztürk, M.
[No abstract available]
Citation - Scopus: 1
Ieee 802.15.4a Based Ultra Wideband Systems for Coexistence With Primary Users
(IEEE, 2015) Fındıklı, Çağlar; Erküçük, Serhat; Çelebi, Mehmet Ertuğrul
Peaceful coexistence is a major implementation issue for both cognitive radios and ultra wideband (UWB) systems. Accordingly the UWB impulse radio (UWB-IR) based Wireless Personal Area Network (WPAN) standard IEEE 802.15.4a has suggested using linear combination of pulses to limit interference to coexisting primary systems. In this paper motivated by implementing the IEEE 802.15.4a based UWB-IR systems for peaceful coexistence we consider the implementation of linear combination of pulses as suggested by the standard. Accordingly we (I) design linearly combined pulses that conform to the standard requirements and (ii) study the UWB-IR system performance in the presence of orthogonal frequency division multiplexing (OFDM) based wideband primary systems with various bandwidths and subcarriers. The study shows that the UWB-IR system performance can be significantly improved by selecting suitable pulses for transmission and employing appropriate filtering techniques at the receiver when the primary system is active. The results are important for the practical implementation of IEEE 802.15.4a based UWB systems coexisting with licensed systems.
Mare Clausum: War and Diplomacy on the Black Sea, 1939 - 91
(De Gruyter, 2024) Işçi, O.
[No abstract available]

Browse

Recent Submissions