Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Conference Object Citation - Scopus: 2Utilization of Near Ir Absorbing Gold Nanocolloids by Green Synthesis(Trans Tech Publications, 2018) Elveren, Beste; Yıldız, Ümit Hakan; Arslan Yıldız, AhuThe rapid developments in nanoscience, and its applications on biomedical areas have a large impact on drug delivery, tissue engineering, sensing, and diagnosis. Gold is widely investigated nanomaterial for the last couple of decades, since it has unique surface properties and very low toxicity to biological environment. In this work, we present a novel synthesis of gold nanoparticles (GNPs) exhibiting both visible and near-IR absorbance without agglomeration. The surface of GNPs were analyzed by routine methods and the binding kinetics were investigated by Surface Plasmon Resonance (SPR) Spectroscopy. The unique optical properties of near-IR asorbing GNP colloids hold promise for biological applications.Conference Object Citation - Scopus: 2A Comparative Study of Modularity-Based Community Detection Methods for Online Social Networks(CEUR Workshop Proceedings, 2018) Karataş, Arzum; Şahin, SerapDigital data represent our daily activities and tendencies. One of its main source is Online Social Networks (OSN) such as Facebook, YouTube etc. OSN are generating continuously high volume of data and define a dynamic virtual environment. This environment is mostly represented by graphs. Analysis of OSN data (i.e.,extracting any kind of relations and tendencies) defines valuable information for economic, socio-cultural and politic decisions. Community detection is important to analyze and understand underlying structure and tendencies of OSNs. When this information can be analysed successfully, software engineering tools and decision support systems can produce more successful results for end users. In this study, we present a survey of selected outstanding modularity-based static community detection algorithms and do comparative analysis among them in terms of modularity, running time and accuracy. We use different real-world OSN test beds selected from SNAP dataset collection such as Facebook Ego network, Facebook Pages network (Facebook gemsec), LiveJournal, Orkut and YouTube networks.Conference Object Citation - WoS: 2Citation - Scopus: 4Monitoring Excimer Formation of Perylene Dye Molecules Within Pmma-Based Nanofiber Via Flim Method(SPIE, 2016) İnci, Mehmet Naci; Açıkgöz, Sabriye; Demir, Mustafa MuammerConfocal fluorescence lifetime imaging microscopy method is used to obtain individual fluorescence intensity and lifetime values of aromatic Perylene dye molecules encapsulated into PMMA based nanofibers. Fluorescence spectrum of aromatic hydrocarbon dye molecules, like perylene, depends on the concentration of dye molecules and these dye molecules display an excimeric emission band besides monomeric emission bands. Due to the dimension of a nanofiber is comparable to the monomer emission wavelength, the presence of nanofibers does not become effective on the decay rates of a single perylene molecule and its lifetime remains unchanged. When the concentration of perylene increases, molecular motion of the perylene molecule is restricted within nanofibers so that excimer emission arises from the partially overlapped conformation. As compared to free excimer emission of perylene, time-resolved experiments show that the fluorescence lifetime of excimer emission of perylene, which is encapsulated into NFs, gets shortened dramatically. Such a decrease in the lifetime is measured to be almost 50 percent, which indicates that the excimer emission of perylene molecules is more sensitive to change in the surrounding environment due to its longer wavelength. Fluorescence lifetime measurements are typically used to confirm the presence of excimers and to construct an excimer formation map of these dye molecules.Conference Object Approximate Best Linear Unbiased Channel Estimation for Multi-Antenna Frequency Selective Channels With Applications To Digital Tv Systems(SPIE, 2004) Özen, Serdar; Pladdy, Christopher; Nerayanuru, Sreenivasa M.; Fimoff, Mark J.; Zoltowski, Michael D.We provide an iterative and a non-iterative channel impulse response (CIR) estimation algorithm for communication receivers with multiple-antenna. Our algorithm is best suited for communication systems which utilize a periodically transmitted training sequence within a continuous stream of information symbols, and the receivers for this particular system are expected work in a severe frequency selective multipath environment with long delay spreads relative to the length of the training sequence. The iterative procedure calculates the (semi-blind) Best Linear Unbiased Estimate (BLUE) of the CIR. The non-iterative version is an approximation to the BLUE CIR estimate, denoted by a-BLUE, achieving almost similar performance, with much lower complexity. Indeed we show that, with reasonable assumptions, a-BLUE channel estimate can be obtained by using a stored copy of a pre-computed matrix in the receiver which enables the use of the initial CIR estimate by the subsequent equalizer tap weight calculator. Simulation results are provided to demonstrate the performance of the novel algorithms for 8-VSB ATSC Digital TV system. We also provide a simulation study of the robustness of the a-BLUE algorithm to timing and carrier phase offsets.Article Citation - Scopus: 19Application of Geothermal Energy and Its Environmental Problems in Turkey(Inderscience Enterprises Ltd., 2015) Baba, AlperHuman beings have been benefiting from geothermal energy for different uses since the dawn of the civilisation in many parts of the world. One of the earliest uses of geothermal energy was for heating and it was used extensively by Romans in Turkey. The Aegean region is favoured by a large number of thermal springs known since ancient times. However, it was first in the 20th century that geothermal energy was used on a large scale for direct use and electricity generation. The country's installed heat capacity is 2,705 MWt for direct use and 322.39 MWe for power production. In parallel to developing geothermal energy applications in Turkey, many sites are now experiencing problems such as water contamination associated with geothermal fluid. Especially, the high temperature solution of elements and compounds, causes operational limitations in geothermal power plants. These limitations are due to the severe scaling and corrosion of geothermal fluid. Copyright © 2015 Inderscience Enterprises Ltd.Conference Object Citation - Scopus: 1Evaluation of the Conservation Activities in the Historical Settlement Tenedos-Bozcaada Island(WITPress, 2011) Akpınar, Figen; Saygın, Nicel; Karakaya, EmelThe efforts for the conservation of cultural heritage in historical settlements are a highly problematic and multi-faceted issue in Turkey. Although the conservation legislation dates back 50 years, the cultural heritage has not been internalized and not accepted in wider parts of the society and, has not found a solid political base. The historical and cultural heritage areas are mostly marketed for tourism and turned into places as the simulacrum of the elitist and middle class tastes. Tenedos (Bozcaada) Island inherits the rich cultural heritage of two millennia. The Island is in danger of losing its social, cultural and multi-ethnical characteristic where Turkish and Greek societies live harmoniously. The architectural, economic and ecological values are also in danger because of the rise of touristic activities and the construction of vacation homes as well as the State's withdrawal to provide subsidy to the agricultural sector that took place after the 1980s in parallel with the general economic policies adopting global economic restructuring. The objective of the paper is to highlight the multidimensional character of the social and spatial process which is enmeshed in the conservation activities of the Island. The values and norms, social, economic considerations in the conservation activities need a new approach and, without existence of a common will and a wider participation of the society it is hard to expect any success in the conservation of the rich cultural values, and to assess, develop and carry them into the future. A bundle of techniques are used: a large survey analysis of the area is realized and its social, historical and physical characteristics are documented. Questionnaires, in-depth interviews are used in order to detect the difficulties for conservation of the heritage in part of the responsible public bodies. The public and tourism sector opinions, thoughts and aspirations are surveyed. Even though, the preservation of Tenedos Island's cultural heritage appears to be a difficult challenge, there seems to be some positive clues for the future. © 2011 WIT Press.Conference Object Citation - Scopus: 2A Maximum Degree Self-Stabilizing Spanning Tree Algorithm(Springer Verlag, 2010) Çokuslu, Deniz; Erciyeş, Kayhan; Hameurlain, AbdelkaderSpanning trees are fundamental topological structures in distributed environments which ease many applications that require frequent communication between nodes. In this paper, we examine and compare two spanning tree construction algorithms which rely on classical and self stabilization approach. Then, we propose a new self-stabilizing spanning tree construction algorithm which uses maximum degree heuristic while choosing the root node. We show experimentally that our new algorithm provides smaller tree diameters than the two existing approaches with favorable run-times. © 2011 Springer Science+Business Media B.V.Conference Object Citation - WoS: 9Citation - Scopus: 13Design of a Haptic Device for Teleoperation and Virtual Reality Systems(Institute of Electrical and Electronics Engineers Inc., 2009) Dede, Mehmet İsmet Can; Selvi, Özgün; Bilgincan, Tunç; Kant, YalkınHaptics technology has increased the precision and telepresence of the teleoperation and precision of the in-house robotic applications by force and surface information feedback. Force feedback is achieved through sending back the pressure and force information via a haptic device as the information is created or measured at the point of interest. In order to configure such a system, design, analysis and production processes of a haptic device, which is suitable for that specific application, becomes important. Today, haptic devices find use in assistive surgical robotics and most of the teleoperation systems. These devices are also extensively utilized in simulators to train medical and military personnel. The objective of this work is to design a haptic device with a new structure that has the potential to increase the precision of the robotic operation. Thus, literature is reviewed and possible robot manipulator designs are investigated to increase the precision in haptics applications. As a result of the investigations, conceptual designs are developed. Ultimately, final design is selected and produced after it is investigated in computer-aided- design (CAD) environment and its kinematic and structural analyses are carried out.