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Conference Object Citation - Scopus: 1Characterization of satellite transponder impairments based on simulations with test data(Institute of Electrical and Electronics Engineers Inc., 2015) Ulubey,O.; Gulgonul,S.; Kara,A.A satellite transponder simulator based on actual test data of TURKSAT 3A satellite has been developed to analyze degradation in multicarrier scenarios. Communication impairment sources through a transponder are explained in conjunction with a methodology defined to characterize total degradation resulting from them. Several transponder utilization scenarios are studied with respect to total degradation and optimum operation conditions are demonstrated. © 2015 IEEE.Conference Object Citation - Scopus: 2New Wavelet-Based Features for the Recognition of Jittered and Stagger Pri Modulation Types;(Institute of Electrical and Electronics Engineers Inc., 2015) Gencol,K.; Kara,A.; At,N.In dense electronic warfare environments, numerous emitters can be active simultaneously and an interleaved stream of pulses in natural time of arrival order is received by the Electronic Support Measures (ESM) receiver. It is the task of the ESM system to de-interleave this mixed pulse sequence and thus to identify the surrounding threatening emitters. In this processing, pulse repetition interval (PRI) modulation recognition has a significant role due to the fact that it can reveal the hidden patterns inside pulse repetition intervals and thus help identify the emission source and its functional purpose. In this paper, we propose new wavelet-based features for the recognition of jittered and stagger PRI modulation types. The recognition of these types are heavily based on histogram features. Experimental results show that the proposed feature set have very high recognition rates and outperform histogram based methods. © 2015 IEEE.Conference Object Citation - Scopus: 1Development of a Digital Communications Course Enriched by Virtual and Remote Laboratory Tools(2011) Kara,A.; Kara, Ali; Cagiltay,N.; Çağıltay, Nergiz; Dalveren,Y.; Dalveren, Yaser; Kara, Ali; Çağıltay, Nergiz; Dalveren, Yaser; Department of Electrical & Electronics Engineering; Software Engineering; Department of Electrical & Electronics Engineering; Software EngineeringDigital communications is a basic concept for rapidly growing fields of Electrical, Computer and Electronics Engineering like wireless and mobile communication systems, radar and electronic warfare, telemetry and many signal processing techniques. A re-designed digital communications course with ICT (Information and Communication Technologies) based diverse tools including matlab assignments, remote experiments and interactive simulators is described in this study. First, the objectives of the course, learning outcomes and evaluation methods are described. The re-designed course is offered in the last semester at Atilim University, and performance increase in students is compared with the previous year's offering, and by evaluating the course on a topic-based approach. © 2011 IEEE.Conference Object Citation - Scopus: 1Analysis of Measurement Instrumentation Delay in Modular Experimental Radar at C Band(Institute of Electrical and Electronics Engineers Inc., 2018) Abdulrazigh,M.Y.A.; Uzundurukan,E.; Kara,A.Unlike pulsed radars, Frequency-Modulated Continuous Wave (FMCW) radar emits continuously very low power levels with the same signal to noise ratio (SNR) of an equivalent pulsed radar. FMCW can measure range and speed of the target. In modular design of such radar, time delay is experienced due to modular components such as low-noise amplifiers (LNA), antennas and, especially, cables. This time delay causes frequency shifts in the measured beat frequency resulting a range measurement error. Therefore, this time delay has to be studied for accuracy of measurements. In this study, experimental results of range measurement errors of a FMCW radar operating at C band are presented. Considering time delay of modular components, a range error of approximately 0.1m was obtained within a range of 10m. © 2018 IEEE.Conference Object Citation - Scopus: 7Software Technologies, Architectures and Interoperability in Remote Laboratories(2010) Özbek,M.E.; Kara,A.; Ataş,M.A remote laboratory aims to provide access to remote lab equipment over the internet. The design and development of the client software is subject to various requirements. In this paper we discuss these requirements and propose solutions. Implementations are demonstrated for some remote experiments developed in the ERRL project. An XML format for experimental results is proposed as an attempt towards standardization of remote laboratory interfaces and enhancing the interoperability of diverse remote laboratory applications. ©2010 IEEE.Conference Object Pilot Remote Experiment in the Errl: Measurement of Scattering Parameters(2007) Özen,M.; Aydin,E.U.; Kara,A.A remote laboratory platform enables the learners to access physical instruments at distant location and to perform experiments remotely via the Internet. This paper focuses on a pilot remote laboratory experiment on measurement of scattering parameters (s parameters) by using vector network analyzer (VNA) in the ERRL (European Remote Radio Laboratory) platform. The results of the pilot experiment are presented, and discussed shortly. © 2007 IEEE.Conference Object Citation - Scopus: 1Development of a low cost radio controller for Tele operation systems: Crane controller design as an industry sponsored undergraduate research(2013) Kaynaköz,G.; Daǧdeviren,B.; Kapusuz,K.Y.; Kara,A.This study presents some of the design and development stages of a radio control system for dense interference environments. All design and development stages were conducted by undergraduate students, with an undergraduate research project sponsored by a local company. The study starts with an overview of the system including choice of main components and modules. Then, it discusses the design stages of the system from analog to digital conversion to driving circuit of the targeted mechanical system (crane), and provides some preliminary results and conclusions. One of the design criteria in the project was minimization of the cost and size, and the preliminary results have shown that the prototype could compete with many commercial equivalents.Conference Object Citation - Scopus: 20Design and Development of a Remote and Virtual Environment for Experimental Training in Electrical and Electronics Engineering(2010) Kara,A.; Aydin,E.; Ozbek,M.E.; Cagiltay,N.European 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.Article Citation - Scopus: 11Modelling of Shadowing Loss Due To Huge Non-Polygonal Structures in Urban Radio Propagation(Electromagnetics Academy, 2008) Kara,A.; Yazgan,E.Ray tracing algorithms rely on two dimensional or three dimensional database. They use ray optical techniques referred to as the uniform theory of diffraction (UTD) using building database given as polygons. Building geometries can also be modelled as having non-planar geometries, and this would be important in modeling of shadowing loss due to curved structures in urban radio propagation. To demonstrate modelling of buildings as non-polygonal geometries, a particular building composition involving 3D cruved geometries is chosen, and shadowing loss for this building composition is studied via UTD ray tracing. Building structure considered in this study involves main canonical shapes of non-planar geometries including cone, cylinder and sphere. Single and multiple interaction of surface diffractions, effect of creeping waves are taken into consideration in the analysis. © 2008, Electromagnetics Academy.Conference Object Citation - Scopus: 4Distance Laboratory Applications Errl: a Study on Radio Communication in Electronic Field(2008) Aydin,C.Ç.; Türkmen,G.; Özyurt,E.; Aydm,E.U.; Çaǧiltay,N.E.; Özbek,M.E.; Kara,A.In the last decade, the effect of internet usage in education is gradually increased. When we look from academic perspective, the new technologies provided alternatives for students learning. As distance education becomes important everyday, the indispensable elements of teaching and education, laboratories must be reachable via remote connection. Consequently, the education that is going to be given to the students will be more flexible with respect to place and time constraints and students can reach laboratory facilities at any time and anywhere not only in lectures and practical hours. In this study, European Remote Radio Laboratory (ERRL) which is a distance remote Radio Frequency (RF) laboratory designed for electrical-electronics students, is described generally. The software architecture, infrastructure and experiment that can be done with a remote connection have been described.
