WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Master Thesis QOS-AWARE DOWNLINK SCHEDULING ALGORITHM FOR LTE NETWORKS: A CASE STUDY ON EDGE USERS(Abdullah Gül Üniversitesi, 2016) UYAN, OSMAN GÖKHAN4G/LTE (Long Term Evolution) is the state of the art wireless mobile broadband technology. It allows users to take advantage of high internet speeds. It makes use of the OFDM technology to offer high speed, which supplies the system resources both in time and frequency domain. The allocation of these resources is operated by a scheduling algorithm running on the base station. In this thesis, we investigate the performance of existing downlink scheduling algorithms in two ways. First we look at the performance of the algorithms in terms of throughput and fairness metrics. Second, we suggest a new fairness criterion, QoS-aware fairness which accepts that the system is fair if it can supply the users with the packet delays that they demand, and we evaluate the performance of the algorithms according to this metric. We also propose a new algorithm according to these two metrics, which especially increase the throughput gained by the edge users, the QoS-fairness, and classical fairness of the system without causing a big degradation in cell throughput when compared to other schedulers.Conference Object In-Silico Methods to Identify Common MicroRNAs and Pathways of Neuromuscular Diseases(IEEE, 345 E 47TH ST, NEW YORK, NY 10017 USA, 2019-04) Yazici, Miray Unlu; Menges, Evrim Aksu; Ulum, Yeliz Z. Akkaya; Hayta, Burcu Balci; Bakir-Gungor, Burcu; Balcihayta, Burcu; Akkaya Ulum, Yeliz Z.Neuromuscular disorders (NMD) are a heterogeneous group of diseases characterized by the loss of function of the peripheral nerves and muscles. However, there are no effective and widespread therapeutic approaches to prevent or delay the progression of these disease types. microRNAs (miRNAs) which cause significant changes in gene expression by binding to target messenger RNAs (mRNAs), are known to have an effect on disease mechanisms. In this study, by integrating different bioinformatics methods, we aim to find miRNAs, target genes and pathways related to a group of neuromuscular diseases. For this purpose, we determined 17 miRNAs that show significant expression changes between patient and healthy groups; predicted target genes of these miRNAs; and identified affected pathways using subnetwork discovery, functional enrichment based algorithms. In our study, we integrated different in-silico approaches that proceed in top-down manner or bottom-up manner. The identified candidate miRNAs, genes and pathways, which could help to explain neuromuscular disease development mechanisms, are now under investigation in wet-lab.Article Dayım: Bir İnsanoğlunun Portresi(TURKISH LIBRARIANS ASSOC, YENISEHIR, NECATIBEY CAD, ELGIN SOK, PO BOX 175, ANKARA, 06440, TURKEY, 2019) Donmez, Rasim OzgurThis is a memoir written by his nephew about our colleague Ali Can, who passed away in last July.Article Citation - WoS: 38Citation - Scopus: 38pH- and Temperature-Responsive Amphiphilic Diblock Copolymers of 4-Vinylpyridine and Oligoethyleneglycol Methacrylate Synthesized by RAFT Polymerization(Elsevier Sci Ltd, 2014-01) Topuzogullari, Murat; Bulmus, Volga; Dalgakiran, Eray; Dincer, SevilDiblock copolymers of 4-vinylpyridine (4VP) and oligoethyleneglycol methyl ether methacrylate (OEGMA) were synthesized for the first time using RAFT polymerization technique as potential drug delivery systems. Effects of the number of ethylene glycol units in OEGMA, chain length of hydrophobic P4VP block, pH, concentration and temperature on the solution behavior of the copolymers were investigated comprehensively. Copolymer chains formed micelles at pH values higher than 5 whereas unimeric polymers were observed to exist below pH 5, owing to the repulsion between positively charged P4VP blocks. The size of the micelles was dependent on the relative length of blocks, P4VP and POEGMA. Thermo-responsive properties of copolymers were investigated depending on the pH and length of P4VP block. The increase in the length of P4VP block decreased the LCST substantially at pH 7. At pH 3, LCST of copolymers shifted to higher temperatures due to the increased interaction of copolymers with water through positively charged P4VP block. (C) 2013 Elsevier Ltd. All rights reserved.Article Citation - WoS: 5Workplace Diversity and Intercultural Communication: A Phenomenological Study(Taylor & Francis As, 2017-01-01) Evans, Adam; Suklun, HarikaFor decades, the United States has seen an increasing number of immigrants, which has led to a significant increase in cultural diversity in the United States. This phenomenological study examines the contextual history of professional non-native English-speaking women in the United States to form a basis of comparison with native English speakers. It attempts to compare their lived communicative experiences with those of non-native English speakers in the workplace. In this study, 16 professional, native English-speaking women currently working in the US were interviewed. Participants in this study were asked to describe professional and intercultural experiences through interactions with non-native English-speaking coworkers, any expectations of the interactions or violations of those expectations, and any miscommunications that may have occurred. Many native English speakers positively reflected upon these intercultural interactions and shared examples of their vocal adjustments and challenges of verbal and intercultural communication. To overcome these challenges, professional native English speakers described trying to slow speech or asking confirming questions such as Do you understand? to mitigate verbal conflicts and miscommunication. Based on the trends within the responses, however, there is a potential for unintentional and often offensive consequences to occur. Several coping mechanisms were found to be considered rude or off-putting by non-native speakers, while the intent of a more direct message was often misinterpreted by native English speakers. In addition, it seems that native English speakers often may have good intentions in their actions but do not have the skillset to better facilitate communication with non-native English speakers.Article Citation - WoS: 19Citation - Scopus: 21Wireless Sensing in Complex Electromagnetic Media: Construction Materials and Structural Monitoring(IEEE-Inst Electrical Electronics Engineers Inc, 2015-10) Ozbey, Burak; Demir, Hilmi Volkan; Kurc, Ozgur; Erturk, Vakur B.; Altintas, AyhanIn this paper, wireless sensing in the presence of complex electromagnetic media created by combinations of reinforcing bars and concrete is investigated. The wireless displacement sensing system, primarily designed for use in structural health monitoring (SHM), is composed of a comb-like nested split-ring resonator (NSRR) probe and a transceiver antenna. Although each complex medium scenario is predicted to have a detrimental effect on sensing in principle, it is demonstrated that the proposed sensor geometry is able to operate fairly well in all scenarios except one. In these scenarios that mimic real-life SHM, it is shown that this sensor exhibits a high displacement resolution of 1 mu m, a good sensitivity of 7 MHz/mm in average, and a high dynamic range extending over 20 mm. For the most disruptive scenario of placing concrete immediately behind NSRR, a solution based on employing a separator behind the probe is proposed to overcome the handicaps introduced by the medium. In order to obtain a one-to-one mapping from the measured frequency shift to the displacement, a numerical fit is proposed and used. The effects of several complex medium scenarios on this fit are discussed. These results indicate that the proposed sensing scheme works well in real-life SHM applications.Article Citation - WoS: 24Citation - Scopus: 26Wireless Measurement of Elastic and Plastic Deformation by a Metamaterial-Based Sensor(MDPI, 2014-10-20) Ozbey, Burak; Demir, Hilmi Volkan; Kurc, Ozgur; Erturk, Vakur B.; Altintas, AyhanWe report remote strain and displacement measurement during elastic and plastic deformation using a metamaterial-based wireless and passive sensor. The sensor is made of a comb-like nested split ring resonator (NSRR) probe operating in the near-field of an antenna, which functions as both the transmitter and the receiver. The NSRR probe is fixed on a standard steel reinforcing bar (rebar), and its frequency response is monitored telemetrically by a network analyzer connected to the antenna across the whole stress-strain curve. This wireless measurement includes both the elastic and plastic region deformation together for the first time, where wired technologies, like strain gauges, typically fail to capture. The experiments are further repeated in the presence of a concrete block between the antenna and the probe, and it is shown that the sensing system is capable of functioning through the concrete. The comparison of the wireless sensor measurement with those undertaken using strain gauges and extensometers reveals that the sensor is able to measure both the average strain and the relative displacement on the rebar as a result of the applied force in a considerably accurate way. The performance of the sensor is tested for different types of misalignments that can possibly occur due to the acting force. These results indicate that the metamaterial-based sensor holds great promise for its accurate, robust and wireless measurement of the elastic and plastic deformation of a rebar, providing beneficial information for remote structural health monitoring and post-earthquake damage assessment.Editorial What Does the Water Inside the Brain Tell Us? Diffusion Tensor Imaging(Sciendo, 2018-10-01) Acer, Niyazi; Dundar, Mehmet Sait; Bastepe-Gray, SerapThe brain consist of about 75 percent water. Diffusion tensor imaging (DTI) is an advanced magnetic resonance (MR) technique imaging that has been developed for diagnostic and research in medicine. It can be use DTI tractography to better understand degenerating axons of white matter lesions in some neurological diseases such as MS, AD, trauma, cerebral ischemia, epilepsy, brain tumors and metabolic disorders.Article Citation - WoS: 25Citation - Scopus: 33Volume Fraction, Thickness, and Permeability of the Sealing Layer in Microbial Self-Healing Concrete Containing Biogranules(Frontiers Media S.A., 2018-11-23) Ersan, Yusuf Cagatay; Palin, Damian; Tasdemir, Sena Busra Yengec; Tasdemir, Kasim; Jonkers, Henk M.; Boon, Nico; De Belie, Nele; Yengec Tasdemir, Sena BusraAutonomous repair systems in construction materials have become a promising alternative to current unsustainable and labor-intensive maintenance methods. Biomineralization is a popular route that has been applied to enhance the self-healing capacity of concrete. Various axenic microbial cultures were coupled with protective carriers, and their combination appears to be useful for the development of healing agents for realizing self-healing concrete. The advantageous traits of non-axenic cultures, such as economic feasibility, self-protection, and high specific activity have been neglected so far, and thus the number of studies investigating their performance as healing agents is scarce. Here we present the self-healing performance of a mortar containing a healing agent consisting of non-axenic biogranules with a denitrifying core. Mortar specimens with a defined crack width of 400 mu m were used in the experiments and treated with tap water for 28 days. Self-healing was quantified in terms of the crack volume reduction, the thickness of the sealing layer along the crack depth and water permeability under 0.1 bar pressure. Complete visual crack closure was achieved in the bio-based specimens in 28 days, the thickness of the calcite layer was recorded as 10 mm and the healed crack volume was detected as 6%. Upon self-sealing of the specimens, the water permeability decreased by 83%. Overall, non-axenic biogranules with a denitrifying core shows great potential for development of self-healing bioconcrete.Article Citation - WoS: 7Citation - Scopus: 8Using Students' Performance to Improve Ontologies for Intelligent E-Learning System(Edam, 2015) Icoz, Kutay; Sanalan, Vehbi A.; Cakar, Mehmet Akif; Ozdemir, Esra Benli; Kaya, SukruOntologies have often been recommended for E-learning systems, but few efforts have successfully incorporated student data to represent knowledge conceptualizations. Defining key concepts and their relations between each other establishes the backbone of our E-learning system. The system guides an individual student through his/her course by evaluating their progress and suggesting instructional material to review based upon their answers. Three main tasks are performed within this framework: building ontologies for the course, measuring a student's understanding level for the concepts, and making personal suggestions to create an individualized learning environment. This paper presents: the integration of ontologies, assisted with student data, together with an intelligent Recommendation Module for the development of an E-learning system; the comparison and correction adaption of ontology from students' mind maps; and the assessment of students' actual weaknesses in comparison to what Recommendation Module suggests. The sample of 127 students, five classrooms, was conveniently selected among seventh grade students of a demographically average school in a major city in Turkey. The students' achievement was assessed and the scores for different questions were investigated for associations with concepts made in the students' minds. The results provided significant correlations among scores, and a fit model for the concepts represented by questions. The student suggested model slightly differed from the ontology map from the experts. Based on the data-supported model, the Recommendation Module more accurately determined the students' learning deficiencies and suggested concepts to be reviewed.