Electrical & Electronics Engineering
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Browsing Electrical & Electronics Engineering by Subject "electrical & electronics engineering"
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Item A Magnetic Measurement System and Identification Method for Buried Magnetic Materials Within Wet and Dry Soils(IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, 2016-03-04) EGE, Yavuz; NAZLIBİLEK, Sedat; KAKİLLİ, Adnan; ÇITAK, Hakan; KALENDER, Osman; ERTÜRK, Korhan Levent; ŞENGÜL, Gökhan; KARAÇOR, Deniz—In this paper, a new magnetic measurement system is developed to determine upper surfaces of buried magnetic materials, particularly land mines. This measurement system uses the magnetic-anomaly-detection method. It also has intelligent identification software based on an image matching algorithm. It is aimed to determine and identify the buried ferromagnetic materials with minimum energy consumption. It is concentrated on the detection and identification of the shapes of upper sur faces of buried magnetic materials in dry and wet conditions. The effect of humidity in the detection process for detection is tested. In this paper, we used sensor images to identify various ferromagnetic materials and similar objects. Sensor images of soils at various humidities covering the objects were obtained. We used the speeded-up-feature-transform algorithm in the comparison process of the images. Dry soil sample images match with the corresponding wet soil samples with the highest matching rate. The images for different objects can easily be distinguished by the matching process.Item A New RF and Microwave Engineering Course Enriched With Advanced Technologies(2010-02-08) AYDIN, Elif; ÇAĞILTAY, NergizIn this study, a curriculum model including recent developments and technologies in the Radio Frequency (RF) and Microwave Engineering field by using a blended approach is proposed. This study covers the description of the content of theoretical and hands on applications, the integration model of the technological tools into the proposed curriculum, and the instructional approaches used in the new course design. The main goal of the course is to prepare students for future professional careers in RF and Microwave Engineering by supporting them with new instructional technologies. The secondary goal of the course is to better prepare the students for the sequence of senior courses in the Electrical and Electronics Engineering program of Atilim University. The course is structured with a balance between theory and laboratory, including remote and in lab measurement experiments as well as modeling and designing microwave components by means of computer tools and design fabrication. The newly designed course is implemented at the Atilim University. The study also reports the first semester implementation.Item A REMOTE LABORATORY FOR TRAINING IN RADIO COMMUNICATIONS: ERRL(IEEE, 2007-08-10) KARA, Ali; AYDIN, Elif; ÖKTEM, Ruşen; ÇAĞILTAY, NergizThis paper presents, first, a short survey of remote laboratory initiatives in electrical and computer engineering, and then discusses design and development phases of remote laboratory environment on radio communications, the ERRL (European Remote Radio Laboratory). As being the first attempt in establishing of such a large scale remote laboratory on radio communications, ERRL enables access to high technology RF equipments and setups through the Internet. The software structure, target groups and experimental set ups of ERRL are shortly discussed. First attempts on implementation of pilot experiments are discussed.Item A WEB BASED TRAINING MODULE FOR TEACHING DIGITAL COMMUNICATIONS(2015-06-02) KARA, Ali; ERDEM, Cihangir; ÖZBEK, Mehmet Efe; ÇAĞILTAY, Nergiz; AYDIN, ElifAn interactive module which simulates a digital transmission link from one end to the other has been designed. Using the module, a user may enter a short audio/message signal using microphone of a PC, and then follows processes on the signal at each stage of the digital transmission link. The user can also analyze the signal at every stage of the link, and compare the performance of various modulation schemes used in the link, and finally may see how the audio signal is corrupted by noise in the transmission link. In this way, from source point to destination point of the signal, the user may study various stages such as analog to digital conversion, analysis of effects of Gaussian noise on the message signal.Item An Indoor Navigation Aid Designed for Visually Impaired People(2008 34th Annual Conference of IEEE Industrial Electronics, 2008-08-09) ÖKTEM, Ruşen; AYDIN, Elif; ÇAĞILTAY, NergizThis 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.Item Customizing SSL Certificate Extensions to Reduce False-Positive Certificate Error/Warning Messages(International Journal of Information Security Science, 2016-08-04) TARAZAN, Şafak; BOSTAN, AtilaIn today’s Internet world, X.509 certificates are commonly used in SSL protocol to provide security for web-based services by server/client authentication and secure communication. Although SSL protocol presents a technical basis, this web security largely depends on user awareness of security measures as well. There are significant number of scientific studies in the literature reporting that the count of invalid or self-signed certificate usage in today’s Internet can not be overlooked. At the same time, quite a number of studies place emphasis on the acquired indifference towards certificate warning messages which are popped up by web browsers when visiting web pages with invalid or self-signed certificates. In this study, with the importance of user’s daily practices in developing habits in mind, we studied a modification of X.509 certificates in order to reduce the number of false-positive certificate-warning pop ups in order to reduce gaining faulty usage habit of invalid certificates.Item Design and development of a remote and virtual environment for experimental training in Electrical and Electronics Engineering(2010 9th International Conference on Information Technology Based Higher Education and Training (ITHET), 2010-05-09) KARA, Ali; AYDIN, Elif; ÖZBEK, Mehme Efe; ÇAĞILTAY, NergizEuropean 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 and 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.Item Distance Laboratory Applications ERRL: A Study on Radio Communication in Electronic Field(Optimization of Electrical and Electronic Equipment, 2008-08-04) AYDIN, Cansu Çiğdem; ÖZYURT, Erdem; AYDIN, Elif; ÇAĞILTAY, Nergiz; ÖZBEK, Efe; ALPARSLAN, CerenIn 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.Item Distance Laboratory Applications ERRL: A Study on Radio Communication in Electronic Field(IEEE, 2008-05-24) AYDIN, Cansu Çiğdem; ÖZYURT, E.; AYDIN, Elif; ÇAĞILTAY, Nergiz; ÖZBEK, Mehmet Efe; ALPARSLAN, Ceren; KARA, AliIn 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.Item Effects of anisotropy in a physical torso phantom on source reconstructions from a current dipole(Noninvasive Functional Source Imaging of the Brain and Heart and the International Conference on Functional Biomedical Imaging, 2007-01-03) LIEHR, Mario; ŞENGÜL, Gökhan; BAYSAL, Uğur; HAUEISEN, JensIn this study, we investigated experimentally the influence of anisotropic compartments on source reconstruction using phantom measurements with an artificial current dipole as signal source. The anisotropic compartment was built from single skeins with a nine times higher conductivity than the surrounding solution. We placed the dipole at the lower borders of the anisotropic bulk and measured the magnetic field and the electric potential for each dipole location. The current dipole was rotated in relation to the anisotropic skeins and potentials and fields were recorded for different angles between anisotropic skeins and current dipole. We found that the estimated dipole orientations are strongly influenced by the anisotropy, while the reconstructed position of the dipole is not significantly influenced. We conclude that for bioelectric and biomagnetic source reconstruction, it is necessary to take into account anisotropic structures in the volume conductor if dipole orientations are of interest.Item HOW ASSESSMENT SYSTEM OF AN OPEN SOURCE LEARNING MANAGEMENT SYSTEM CAN BE INTEGRATED TO A REMOTE LABORATORY APPLICATION? PROBLEMS AND SOLUTIONS(The 18th Annual IEEE International Symposium on Personal,Indoor and Mobile Radio Communication (PIMRC’07), 2007-08-04) AYDIN, Cansu Çiğdem; ÇAĞILTAY, NergizMost of the education programs need an assessment system for formative and summative evaluation purposes. Similarly, in the ERRL* project which is a distance remote radio frequency laboratory application, assessment system is required. However, developing an assessment system cost is very high and requires some extra time for testing and development purposes. Open source systems provide these services in a standard way. Since the source is open, it is possible to make some modifications to better adapt these systems to the requirements of developed systems. Similarly, in the Moodle part of the system we need to integrate the test and the experiment platforms. In order to better guide the learners in the system, they should take some tests about the devices and the theoretical content included in the system. It is important to prevent users who do not have the enough knowledge directed to the experiments platform. These testing requirements should be integrated into the remote laboratory system, so that, the learners should not need to jump between different systems and interfaces. This article presents implementation process of open source Learning Management System software’s assessment module to a remote laboratory application and it also discusses the advantages, disadvantages of using an open source Web based assessment system.Item HOW ASSESSMENT SYSTEM OF AN OPEN SOURCE LEARNING MANAGEMENT SYSTEM CAN BE INTEGRATED TO A REMOTE LABORATORY APPLICATION? PROBLEMS AND SOLUTIONS(IEEE, 2007-08-10) AYDIN, Cansu Çiğdem; ÇAĞILTAY, NergizMost of the education programs need an assessment system for formative and summative evaluation purposes. Similarly, in the ERRL* project which is a distance remote radio frequency laboratory application, assessment system is required. However, developing an assessment system cost is very high and requires some extra time for testing and development purposes. Open source systems provide these services in a standard way. Since the source is open, it is possible to make some modifications to better adapt these systems to the requirements of developed systems. Similarly, in the Moodle part of the system we need to integrate the test and the experiment platforms. In order to better guide the learners in the system, they should take some tests about the devices and the theoretical content included in the system. It is important to prevent users who do not have the enough knowledge directed to the experiments platform. These testing requirements should be integrated into the remote laboratory system, so that, the learners should not need to jump between different systems and interfaces. This article presents implementation process of open source Learning Management System software’s assessment module to a remote laboratory application and it also discusses the advantages, disadvantages of using an open source Web based assessment system.Item How to Teach Usage of Equipments in a Remote Laboratory(IEEE, 2007-08-10) ALPARSLAN, Nimet Ceren; ÇAĞILTAY, Nergiz; ÖZEN, Mustafa; AYDIN, ElifEuropean 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.Item İnsan Kafasındaki Dokuların Öziletkenliklerinin in vivo E/MEG Verileri ile Kestirilmesi ve Üç Değişik Kestirim Algoritma Sonuçlarının Karşılaştırılması(Signal Processing and Communications Applications Conference, 2004-08-03) ŞENGÜL, Gökhan; BAYSAL, Uğur; HAUEISEN, JensDoku öziletkenliklerinin bilinmesi, insan vücudunun güvenilir hacim iletken modellerinin oluşturulmasında ve ileri/ters biyoelektrik alan problemlerinin çözümünde gereklidir. Bu çalışmada, insan kafasindaki dokulann öziletkenliklerinin EEG ve MEG verileri kullanılarak in vivo kestirimi ipin üç farklı kestirim algoritmasi kullanılarak elde edilen sonuçlar karşılaştırılmıştır. Uygulanan bu algoritmalar; En Küçük Hatalar Karesi (E.K.H.K) kestirim algoritmasi, Bayesian MAP kestirim algoritmasi ve istatistiksel Kısıtlı Minimum Ortalama Hatalar Karesi (1.K.M.O.H.K) algoritmasıdır. Algoritmalar, geometrik yapı, ön bilgisi ile doku öziletkenlikleri ile doğrusallaştırma ve enstrümantasyon gürültüsünün istatistiksel ön bilgilerini girdi olarak kullanır. E/MEG verileri, medyan sinirin uyarıkdığı kaynak konumlandırma deneyinden sırasıyla 32 kanallı EEG ve 31 kanallı magnetometre ile somatosensory korteks üzerinden ölçülmüştür. Kafanın anatomik geometri bilgisi 256 adet TI ağırlıklı MRI görüntüden elde edilmiş ve kafa derisi, kafatası ve beyin olarak homojen üç bölgeye bölütlendirilmiştir. Sözkonusu algoritmalar kullanılarak kafa derisi, kafatası ve beyin öziletkenlikleri ve hata oranları üç farklı algoritma ile kestirilmiştir. Hata oranları E.K.H.K için %90, Bayesian Map kestirim algoriması için % 20.5 ve İ.K.M.O.H.K algoritması için %12.5 olarak hesaplanmıştır. Sonuçta İ.K.M.O.H.K algoritmasının diğer algoritmalara kıyasla daha düşük hata oranları verdiği gösterilmiştir.Item Maintenance, sustainability and extendibility in virtual and remote laboratories(Social and Behavioral Sciences, 2011-08-10) KARA, Ali; ÖZBEK, Mehmet Efe; ÇAĞILTAY, Nergiz; AYDIN, ElifThis study presents discussions on sustainability of Virtual and Remote Laboratories (VRL), and provides challenges toward maintenance of VRLs. Technical and pedagogical issues in extension and sustenance of VRLs are discussed with the experiences of the authors gained in the development of a VRL system, European Remote Radio Laboratory (ERRL) platform. Moreover, the study presents actions to be taken in sustenance plan and expendability of VRL system with the advances in Information and Communication Technologies (ICT) and educational technologies along with the needs of educators and learners in formal education.Item MERAK ETTİĞİMİZ GEZEGEN “MARS” ve LAZER SPEKTROSKOPİSİ(Bilim ve Teknoloji, 2014-01-13) ESELLER, Kemal EfeBilim insanları, evrende gerçekleşen olayları merak ettiği sürece hayatı kolaylaştıran yeni buluşlara ulaşacak ve her geçen gün bilime daha fazla katkı sağlayacaklardır. Amerikan Havacılık ve Uzay Ajansı (NASA), Mars gezegenine gönderdiği Curiosity (merak) - Rover sistemi ile gezegende çok önceden yaşamış canlı kalıntılarını (mikroplar, tek hücreli canlılar) bulabilmek için araştırmalar yapmakta ve gezegenin tarihi oluşumunu incelemektedir. Mars yüzeyinde, insanoğlu için gerekli Sülfür (S), Nitrojen (N), Oksijen (O), Fosfor (P) ve Karbon (C) gibi elementlerin varlığı ve izleri, gelecekte bu konuda yapılacak araştırma konularını şekillendirmekte ve uygun yaşam koşullarının bulunması için zemin hazırlamaktadır.Item Single Camera Photogrammetry System for EEG Electrode Identification and Localization(Annals of Biomedical Engineering, 2010-04-02) BAYSAL, Uğur; ŞENGÜL, GökhanIn this study, photogrammetric coordinate measurement and color-based identification of EEG electrode positions on the human head are simultaneously implemented. A rotating, 2MP digital camera about 20 cm above the subject’s head is used and the images are acquired at predefined stop points separated azimuthally at equal angular displacements. In order to realize full automation, the electrodes have been labeled by colored circular markers and an electrode recognition algorithm has been developed. The proposed method has been tested by using a plastic head phantom carrying 25 electrode markers. Electrode locations have been determined while incorporating three different methods: (i) the proposed photogrammetric method, (ii) conventional 3D radiofrequency (RF) digitizer, and (iii) coordinate measurement machine having about 6.5 lm accuracy. It is found that the proposed system automatically identifies electrodes and localizes them with a maximum error of 0.77 mm. It is suggested that this method may be used in EEG source localization applications in the human brain.Item Smart Toy Based Learning(Handbook of Research on Educational Communications and Technology, 2014-05-04) ÇAĞILTAY, Kürşat; KARA, Nuri; AYDIN, Cansu ÇiğdemThis chapter examines the general characteristics of and related recent research on smart toys. Smart toys can be defined as new forms of toys featuring both tangible objects and electronic components that facilitate two-way child–smart toy interactions to carry out pur poseful tasks. In this chapter, smart toy based learning projects are discussed and the char acteristics of smart toys as cognitive tools to facilitate learning are analyzed. This chapter also covers the relationship between smart toys and children’s developmental stages—with a particular focus on motivation—in order to understand smart toys’ potential effects on children.Item Use of Advanced Technologies in a RF and Microwave Engineering Course(IEEE, 2010-04-16) AYDIN, Elif; ÇAĞILTAY, NergizIn RF and Microwave Engineering course, usually students struggle to build connections between the theory they have learned and practical applications in the laboratory. The laboratory applications are usually very limited for hands on experience since the high cost and maintenance requirements of the equipment. Additionally, new engineers need to know how to use at least one engineering design tool in order to practice designing RF components, circuits, or antennas. In this study, a curriculum model including recent developments and technologies in the RF and Microwave Engineering field by addressing above problems of the course is proposed. This study covers the description of the content of theoretical and hands on applications, the integration model of the technological tools into the proposed curriculum, and the instructional approaches used in the new course design which covers the use of a remote laboratory environment, Concept Maps and an engineering design tool. The course is structured with a balance between theory and laboratory, including remote and in lab measurement experiments as well as modeling and designing microwave components by means of computer tools and design fabrication. The newly designed course is implemented at the Atilim University. The first semester implementation shows promising results.Item User Study of a New Smart Toy for Children’s Storytelling(Interactive Learning Environments, 2012-08-04) KARA, Nuri; AYDIN, Cansu Çiğdem; ÇAĞILTAY, KürşatThis paper introduces the smart storytelling toy (StoryTech) which provides mixed reality environment. StoryTech with a flexible context leads children to tell their imaginative stories. For usability testing of StoryTech, an empirical study was carried out with totally 90 children. The findings indicated that StoryTech created richer experience especially for age groups of five and six in producing stories.