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Conference Object Citation - WoS: 2Citation - Scopus: 3Design Considerations for Sub-Ghz Multilayer Microstrip Antenna for Near Ground Communication Links in Rural Areas(Ieee, 2017) Bilgin, Gulsima; Yilmaz, Vadi Su; Aydin, Elif; Kara, Ali; Department of Electrical & Electronics Engineering; Electrical-Electronics EngineeringThis paper presents some preliminary results of design and development of sub-GHz multilayer microstip antenna for use in near ground communication applications. In design stage of the antenna, iterative approach was applied. Firstly, a two layer microstrip antenna design process is presented. Next, the corners of the patch were cut, and a vertical wall on all sides of the antenna were introduced. In this way, both the size and resonant freqeuncy can be tuned. Moreover, as an application specific requirement, it is intended to embed this antenna into a metal box in order to protect it from man-made and natural environmental effects. This was also studied, and effects of the embedding ground on the antenna characteristics were examined. It is shown that the designed antenna provides -27dB resturn loss, and 7.3dB peak gain at 915MHz with the dimension of 150x200x13mm. Some preliminary measurements have proven the simulations.Conference Object A Bayes decision model for RSS based location estimation(Ieee, 2007) Dincer, Zeynep; Oektem, Rwen; Aydin, ElifThis work introduces a location estimation method based on Bayes Decision Theory using Radio Signal Strengths for indoor environment. Signal Strengths are observed through three transmitters at three distinct frequencies in UHF band, an active RFID tag and a modem connected to a computer. The test environment is 2100cmx720cm, which is divided into classed of square grids. For each class, a set of received signal strengths are measured and processed. Assuming that the class in which the RFID tag was located in the previous time of measurement is known, the next location (class) is estimated using Bayes Decision Theory. Proposed method is tested in a laboratory environment with obstacles. Results show that proposed method will be successful in location estimation where the estimation error stays within around 2m.Conference Object Citation - WoS: 1Analysis of a Dual Frequency Circular Patch Antenna(Electromagnetics Acad, 2012) Can, Sultan; Kapusuz, K. Yavuz; Aydin, ElifThis study demonstrates resonant frequencies of several shorting pin loaded circular antennas, which are dual-frequency antennas. Dual-frequency operation is formed by using a shorting pin, which is connected between ground and the radiated part of the antenna. There are various studies, which are used to produce dual-frequency operation, and among those methods, a shorting pin is used to form dual frequency circular patch antennas since there are rare studies on this issue and size reduction is possible by inserting a pin to an antenna. This study is done to expand the studies in the literature about a shorting pin loaded circular patch antennas. The parameters that affect the resonant frequencies of the antenna are also evaluated. The thickness, permittivity and shorting pin positions are varied and the resonant frequencies are examined according to the change of these parameters. Frequency ratios are determined for each variation and the results are compared.Article Citation - WoS: 1Citation - Scopus: 3Calculation of Resonant Frequencies of a Shorting Pin-Loaded Etma With Ann(Wiley-blackwell, 2014) Can, Sultan; Kapusuz, Kamil Yavuz; Aydin, Elif[No Abstract Available]Conference Object Study of an Rfid Based Moving Object Tracking System(Istanbul Technical Univ, 2007) Aydin, Elif; Oektem, Rusen; Dincer, Zeynep; Akbulut, I. KaanThis paper presents a study on localization and tracking of an object carrying an active RFID tag. The study incorporates processing of the signals received from transmitters.. in a way to locate and track the coordinate in an indoor environment. During the course of the project,, both outdoor and indoor experiments have been conducted. Empirical distance vs signal strength formulations are formed by use of the collected data. Deviation of the reported values from the theory is analyzed, and the effects of reflections from doors. windows, etc. are observed. In order to improve the accuracy of tracking, Bayesian and Kalman Filtering approaches are incorporated.Conference Object Citation - WoS: 4Dual-Frequency, Two Shorting Pin-Loaded Equilateral Triangular Patch Antennas(Electromagnetics Acad, 2012) Can, Sultan; Kapusuz, K. Yavuz; Aydin, ElifThis study presents the resonant frequencies of several antennas, which are dual-frequency antennas. These antennas possess two shorting pins to form dual frequency. Among several methods to provide dual operation, two shorting pins are used to form dual frequency equilateral triangular antennas since there are limited studies on this issue and higher frequency ratios are achievable. The present study has been done with this in mind in order to contribute to related literature on such antennas. Here, the parameters that affect the resonant frequencies of the antenna are also evaluated. The thickness, side length, and shorting pin positions are changed numerous times, and the resonant frequencies are examined according to the change of these parameters. Finally, the frequency ratios are determined for each variation, and the results are compared. The proposed antennas in present study achieved a frequency ratio around 5.7, which is significantly higher from the ones presented in the literature.Conference Object An Indoor Navigation Aid Designed for Visually Impaired People(Ieee, 2008) Oktem, Rusen; Aydin, Elif; Cagiltay, Nergiz ErcilThis work introduces the hardware architecture and general principles of a portable indoor navigation system for guiding visually impaired people. It operates through wireless communication between a compact hardware interface unit carried by the user, a central processing unit and an active RFID unit. The RFID unit collects signals as regard to the position of the user, the central system processes those signals to estimate the position of the user and proposes a route and direction for the user to follow, whereas hardware interface unit provides interaction. The orienteering of the user is obtained by a tactile compass.Conference Object Citation - WoS: 3An Application of High-Power Electromagnetic Pulse: Forming of Sheet Metal Using Electromagnetic Waves(Ieee, 2015) Inanan, Gokhan; Baranoglu, Besim; Aydin, ElifIn this study, the application of high velocity metal forming process by means of electromagnetic field is proposed. Electromagnetic Sheet Metal Forming (ESMF) is a process of forming sheet metal with very high speed (in milliseconds) without mechanical contact using the energy density of a pulsed magnetic field. In this process, deformation of the workpiece is driven by a transient electric current that is induced in a coil using a capacitor bank and discharge switch. This study presents some experiments and their results by examining the effects of different parameters in the proposed ESMF setup. The analysis and modelling of Electromagnetic sheet metal forming (ESMF) process is presented, as well. It has been seen that, it is possible to design a new system using the outcomes of this study.
