Browsing by Author "Aydin,E."
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Conference Object Citation Count: 0An algorithm for passive RFID based location estimation;(IEEE Computer Society, 2014) Özyurt, Erdem; Aydın, Elif; Yapıcı, Alparslan Çağrı; Department of Electrical & Electronics Engineering; Airframe and Powerplant MaintenanceIn this study, an indoor localization system is developed for the mobile robots. The localization system consists of a passive RFID tag and a reader. The passive RFID tag is placed on the robot and reader antennas are spatially dispersed into the room. For the localization, Selective Adaptive Weighted Centroid Localization (SAWCL) algorithm is used. Performance of the localization system is evaluated for the different tags. © 2014 IEEE.Conference Object Citation Count: 0Analysis of the parameters that effects the operating frequencies and bandwidth of a Cpw-fed patch antenna;(2013) Can, Seçkin; Aydın, Elif; Can,S.; Aydin,E.; Can, Sultan; Department of Electrical & Electronics Engineering; Department of Modern LanguagesIn this study, the analysis of the effect of antenna parameters to the operating frequency is performed in a coplanar waveguide fed patch antenna. The effect of the size and the substrate of the design dual frequency antenna to the operating frequency and bandwidth are also evaluated. Bandwidth of the upper and lower frequency is also investigated and results are demonstrated. The method to increase the bandwidth is also presented by using the chosen parameters. © 2013 IEEE.Conference Object Citation Count: 4An application of high-power electromagnetic pulse: Forming of sheet metal using electromagnetic waves(Institute of Electrical and Electronics Engineers Inc., 2016) Baranoğlu, Besim; Aydın, Elif; Aydin,E.; Department of Electrical & Electronics Engineering; Manufacturing EngineeringIn 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. © 2015 Chamber of Electrical Engineers of Turkey.Conference Object Citation Count: 0A bayes decision model for RSS based location estimation;(2007) Aydın, Elif; Öktem,R.; Aydin,E.; Department of Electrical & Electronics EngineeringThis 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 Count: 4Comparison of computer-based propagation models with experimental data collected in an urban area at 1800 MHz(Institute of Electrical and Electronics Engineers Inc., 2015) Çalışkan, Fatma; Aydın, Elif; Aydin,E.; Department of Electrical & Electronics EngineeringNowadays a lot of models are set for the efficient and economic usage of frequency band since the band is a limited source. Therefore, the propagation models created for this purpose were studied in the literature. These models are Free Space Path Loss (Fspl) + Reflection plus Multiple Diffraction (RMD), COST-Hata and COST-WI models. In order to compare the success of the models, electric field strength measurements were taken in a chosen district (Mustafa Kemal Mahallesi - Ankara, Turkey) where an irregular structure style can be observed. First set of measurements were recorded at random coordinates and second set of measurements were collected by the following coordinates tracking on a single line. As a conclusion, measured values were compared with the results which were taken from the mentioned models with graphical presentations. The most appropriate model was tried to be found and as another aim of the study, a correction factor was generated as a modification for COST-Hata propagation model. © 2015 IEEE.Conference Object Citation Count: 1Design and analysis of rectangular dielectric rod antennas;(Institute of Electrical and Electronics Engineers Inc., 2015) Aydın, Elif; Özkök,M.A.; Çalişkan,F.; Aydin,E.; Department of Electrical & Electronics EngineeringIn this study, rectangular dielectric rod antennas with different dimensions and different shapes are designed and analyzed using HFSS simulation software. To analyze the effects of these changes, five different antennas are designed and antenna gains and return loss values are compared. © 2015 IEEE.Conference Object Citation Count: 20Design and development of a remote and virtual environment for experimental training in electrical and electronics engineering(2010) Kara, Ali; Aydın, Elif; Özbek, Mehmet Efe; Çağıltay, Nergiz; Department of Electrical & Electronics Engineering; Software EngineeringEuropean Remote Radio Laboratory (ERRL) has been developed by the support of European Commission. It intends to provide remote access to high cost devices remotely, and perform experiments in radio frequency (RF), communications and microwave domains of Electrical ad Electronics Engineering. The system has been operational for two years, and been integrated into curriculum of some courses. In this work, the hardware and software structures of the system are presented. Then, experimental content and the motivations in the design of the system are discussed. ©2010 IEEE.Conference Object Citation Count: 0Design and fabrication of dual-frequency h-shaped antenna;(2013) Can, Seçkin; Aydın, Elif; Can,S.; Aydin,E.; Can, Sultan; Department of Electrical & Electronics Engineering; Department of Modern LanguagesIn this study, the parameters that effects the operating frequency of dual frequency H-shaped antenna are examined. These parameters are determined as type of the dielectric constant of substrate, substrate thickness, dimensions of the antenna and dimensions of the slots that are used to obtain shape of H. The produced and simulated results of the proposed antennas are presented and compared with the studies in literature. © 2013 IEEE.Conference Object Citation Count: 0Design considerations for near to the ground communication system and associated Sub-GHz low profile antenna(Institute of Electrical and Electronics Engineers Inc., 2017) Bilgin, Gülsima; Aydın, Elif; Kara, Ali; Kara,A.; Yılmaz, Vadi Su; Department of Electrical & Electronics Engineering; Electrical-Electronics EngineeringThis paper presents propagation aspects of a peer-to peer communication link where antennas are placed near to the ground (low height). First, some of the propagation models are evaluated for understanding of propagation mechanisms. In this regard, as the height of the antennas are very low and the distance is large enough, reflecting angle becomes very small that makes use of two ray model. On the other hand, in the horizontal plane, the positions of the scattering objects, as a source of lateral waves, might vary largely due to the terrain undulations along with variety of objects around the link. This makes propagation mechanisms a little bit complicated. In order to design low profile, high gain sub-GHz antenna for such propagation environment, microstrip antenna with vertical ground was designed and fabricated. The antenna is required to be protected from natural and man-made effects. Therefore, the antenna with associated sensors are embedded into a metal box with a dielectric cover. All these are discussed and some of the findings are presented. © 2017 IEEE.Conference Object Citation Count: 3How to teach usage of equipments in a remote laboratory(2007) Aydın, Elif; Ozen,M.; Cagiltay,N.E.; Aydin,E.; Department of Electrical & Electronics EngineeringEuropean Remote Radio Laboratory (ERRL) is an e-learning project for students, teachers and technicians of the universities who will use the very important devices of this laboratory remotely. These devices are very expensive to buy and can be broken easily while they have been using by the people who does not really know how to use them professionally. As a solution we have developed an e-learning system which aims to support the ERRL learners while studying on how to use equipments in the system. The system is developed according to the electronic performance support systems (EPSS) approach. An EPSS is a computer-based, well-structured system which improves the performance of individuals. It is an electronic infrastructure that contains, stores and distributes personal (individual) or corporate knowledge to enable people to reach necessary levels of performance in the fastest possible time and with minimum teaching support of other people. This paper discusses how the content for such a system is developed and how this content is interactively used in the EPSS platform. The technical details of the developed EPSS are also discussed in this study. We believe that this paper will help instructional system designers for designing different alternatives to improve learners' performance. © 2007 IEEE.Conference Object Citation Count: 3How to teach usage of equipments in a remote laboratory(2007) Aydın, Elif; Ozen,M.; Cagiltay,N.E.; Aydin,E.; Department of Electrical & Electronics EngineeringEuropean Remote Radio Laboratory (ERRL) is an e-learning project for students, teachers and technicians of the universities who will use the very important devices of this laboratory remotely. These devices are very expensive to buy and can be broken easily while they have been using by the people who does not really know how to use them professionally. As a solution we have developed an e-learning system which aims to support the ERRL learners while studying on how to use equipments in the system. The system is developed according to the electronic performance support systems (EPSS) approach. An EPSS is a computer-based, well-structured system which improves the performance of individuals. It is an electronic infrastructure that contains, stores and distributes personal (individual) or corporate knowledge to enable people to reach necessary levels of performance in the fastest possible time and with minimum teaching support of other people. This paper discusses how the content for such a system is developed and how this content is interactively used in the EPSS platform. The technical details of the developed EPSS are also discussed in this study. We believe that this paper will help instructional system designers for designing different alternatives to improve learners' performance. © 2007 IEEE.Conference Object Citation Count: 1Indoor location finding algorithms for mobile robots carrying passive RFID tags(2012) Özyurt, Erdem; Aydın, Elif; Yapıcı, Alparslan Çağrı; Department of Electrical & Electronics Engineering; Airframe and Powerplant MaintenancePrecise localization of mobile robots is critical issue in military, industrial and show business applications. In the literature, several localization techniques has been proposed, in which reader is carried by the mobile object. But in this study a passive Radio Frequency Identification (RFID) tag is attached to mobile robot and the reader antennas being dispersed around the environment. This novelty protects the mobile robot from an increase of weight and results in saving in battery consumption. Also by this way, an increase in mobile object requires a mere increase in low cost passive RFID tags in the navigation system. We have applied a signal pattern matching algorithm, Weighted Centroid Localization (WCL) and Selective Adaptive Weighted Localization (SAWCL) algorithms to locate the tag via Received Signal Strength Indicator (RSSI) and we compare the results. In this study a pilot application is implemented and a prototype is developed to show the proof of concept of the system. © 2012 IEEE.Conference Object Citation Count: 14An indoor navigation aid designed for visually impaired people(IEEE Computer Society, 2008) Aydın, Elif; Aydin,E.; Çaǧiltay,N.E.; Department of Electrical & Electronics EngineeringThis 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. © 2008 IEEE.Conference Object Citation Count: 1Low Radar Cross Section UAV Design in X-Band;(Institute of Electrical and Electronics Engineers Inc., 2022) Aydın, Elif; Sezgin,S.; Gökdoğan, Bengisu Yalçınkaya; Gokdogan,B.Y.; Aydin,E.; Department of Electrical & Electronics Engineering; Electrical-Electronics EngineeringAs Unmanned Aerial Vehicles (UAVs) have become widespread in defense industry, the radar technology that can detect them has also improved. These improvements cause UAVs to be detected more easily, which limits their effectiveness in military usage. Although the reduction of the radar cross-section (RCS) can provide a solution to this issue, the studies regarding that is insufficient in the literature. In this study, a shaping method is recommended to reduce the RCS of UAVs, and it is shown the method is effective to address the problem. Firstly, using a simulation tool, an UAV model is designed from simple shapes and the model is validated by comparing it with the ones in literature. Secondly, RCS values are measured using vertical and horizontal polarization throughout 360 degrees by incrementing the aspect angle by one degree in X-Band using the CST Studio Suite environment. Then, considering the hardware and aerodynamic requirements as well as limitations of the UAV model, a shaping technique is applied to the body, legs and the hollow parts of the UAV model with parametric simulations. The results show that the recommended shaping technique can provide a significant reduction in the RCS of an UAV. © 2022 IEEE.Conference Object Citation Count: 0Microstrip antennas for WiMAX applications;(Institute of Electrical and Electronics Engineers Inc., 2015) Çalışkan, Fatma; Aydın, Elif; Aydin,E.; Department of Electrical & Electronics EngineeringIn this paper, four different antenna types have been designed to be used for WiMAX applications. These antennas have been designed using HFSS simulation software. This paper has included the return loss and the radiation pattern of the designed antennas. Using the simulation results, it is shown that these four antennas are working on Wi-Fi and WiMAX frequency ranges. © 2015 IEEE.Conference Object Citation Count: 0Miniaturized 2.4 GHz Antenna Design for UAV communication link;(Institute of Electrical and Electronics Engineers Inc., 2020) Kara, Ali; Aydın, Elif; Aydin,E.; Yılmaz, Vadi Su; Department of Electrical & Electronics Engineering; Electrical-Electronics EngineeringIn many communications applications, unlike conventional antennas, lightweight, flexible, small antennas that can adapt to mechanical and industrial constraints are required. In this study, the results of antenna design operating at 2.4 GHz are presented for use in Unmanned Aerial Vehicle (UAV) tele command links. In the parametric and optimization studies carried out on the antenna, it is aimed to increase the gain while keeping the size as small as possible. The requirements of the industry, such as light, aesthetics, miniature and high gain aspects of the antenna were targeted in the design process. Finally, an antenna of 55.2x88 mm size and 7dB gain was achieved using commercial electromagnetic design tools. The designed antenna become satisfying industrial requirements with these features. © 2020 IEEE.Conference Object Citation Count: 0Neuronavigation systems and passive usage problem;(Institute of Electrical and Electronics Engineers Inc., 2017) Çağıltay, Nergiz; Tokdemir, Gül; Aydın, Elif; Tokdemir,G.; Maras,H.; Tonbul,G.; Topallı, Damla; Department of Electrical & Electronics Engineering; Computer Engineering; Software Engineering; Information Systems EngineeringNowadays, neuronavigation systems are used in brain surgery procedures, known as a technology to help the surgeon during the operational period. However, the surgeons have faced several problems with the existing systems. Some of these problems are related to the systems software and user interfaces. In this study, such problems are examined and the 'Passive Usage' term is added to the literature by establishing a connection between the problems of endoscopic surgical procedures and similar issues occurred in other domains. The passive usage problem is generalized on different domains for the first time with this study. The results of the study expected to gather up the similar passive usage problems experienced in different domains. Accordingly, the methodologies and studies that are conducted in different research areas may lead to eliminate the Passive Usage problems efficiently. © 2016 IEEE.Conference Object Citation Count: 5Principles for the design of a remote laboratory: A case study on ERRL(2010) Aydın, Elif; Kara, Ali; Kara,A.; Department of Electrical & Electronics EngineeringRemote laboratories are getting very popular in engineering education programs. However, there are not many studies addressing the requirements and design issues of such laboratories. This paper discusses the results of a study of the requirements for developing a remote Radio Frequency (RF) laboratory for university students. This study draws on the perspectives of the students at the university, department of electrical engineering. The results are based on a research study established by 111 engineering students from France, Germany, Romania and Turkey. It investigates how students would like to use the technical content of a state of the art RF laboratory. The result of this study is also compared with the previous outcomes showing perspectives of the other learner groups of such laboratories; engineers and technicians in the technical colleges on the Radio Frequency (RF) domain. Considering the outcomes developed so far, some principles that need to be considered while designing and developing such a laboratory have been proposed. As a case study the proposed principles are implemented in a remote laboratory project. In this paper, the details of user requirements of such laboratories, the proposed principles and the implementation examples are all provided and discussed. Primarily, the general aim of this study is to guide remote laboratory platform developers towards the most effective design of their platforms. © 2010 IEEE.Conference Object Citation Count: 7Study of an RFID based moving object tracking system(2007) Aydın, Elif; Öktem,R.; Dinçer,Z.; Akbulut,I.K.; Department of Electrical & Electronics EngineeringThis 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 Count: 7Study of an RFID based moving object tracking system(2007) Aydın, Elif; Öktem,R.; Dinçer,Z.; Akbulut,I.K.; Department of Electrical & Electronics EngineeringThis 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.