Now showing items 1-20 of 124

  • A broadband microwave amplifier design by means of immittance based data modelling tool 

    In this paper a practical broadband microwave amplifier design algorithm is introduced utilizing the immittance data-modelling tool. In the course of design first the optimum input and output terminations for the active device are produced employing the real frequency technique. Then these terminations are modelled utilizing the new immittance-modelling tool to synthesize the front-end and back-end matching networks. An example is included to exhibit the implementation of the proposed design ...

  • A Computerized Recognition System for the Home-Based Physiotherapy Exercises Using an RGBD Camera 

    Authors:Ar, Ilktan; Akgül, Yusuf Sinan
    Publisher and Date:(IEEE, 2014)
    Computerized recognition of the home based physiotherapy exercises has many benefits and it has attracted considerable interest among the computer vision community. However most methods in the literature view this task as a special case of motion recognition. In contrast we propose to employ the three main components of a physiotherapy exercise (the motion patterns the stance knowledge and the exercise object) as different recognition tasks and embed them separately into the recognition system. ...

  • A country-specific analysis on internet interconnection ecosystems 

    Authors:Cakmak, Gorkem; Aydın, Mehmet Nafiz
    Publisher and Date:(IEEE, 2018)
    With the proliferating number of diverse participants and destinations to reach the Internet construct has become more intricate to assay. Today Internet Service Providers (ISPs) establish resilient networks from multiple providers and broaden the number of peering links-as financially as viable. However the complex structure of the global Internet ecosystem and entwined roles of Internet players simply prevent us from conducting generalized models for grasping interconnections which could be ...

  • A New Technique for OFDM: OFDM-Index Modulation 

    Authors:Basar, Ertugrul; Aygölü, Ümit; Panayirci, Erdal
    Publisher and Date:(IEEE, 2013)
    In this study a novel scheme called orthogonal frequency division multiplexing with index modulation (OFDMIM) is proposed for frequency selective channels. In this scheme the information is conveyed not only by only M -ary signal constellations as in classical OFDM but also by the indices of the active subcarriers which are determined according to the information bits. Different transceiver structures have been investigated for the proposed scheme and it has been shown via computer simulations ...

  • A Novel Approach for Voltage Control in Electrical Power Distribution Systems 

    This paper proposes a novel approach for voltage control in 3-phase unbalanced distribution systems. The approach is based on the change of the magnetizing reactances of the voltage regulators in the system. We used an augmented Lagrangian-based optimization model to determine the optimal settings on a modified IEEE 123 Bus Test System with large PV penetration. Simulations were performed on a minute-based resolution either by controlling regulators or by controlling the magnetizing reactances of ...

  • A Novel Image Steganography Technique based on Similarity of Bits Pairs 

    Authors:Shehzad, Danish; Daǧ, Tamer
    Publisher and Date:(IEEE, 2017)
    Steganography is one of the most important information hiding mechanism which can be used along with cryptography for providing adequate data security. The common Steganographic mediums used are text image audio and video for hiding secret information. In the case of image medium mostly least significant bits of pixels of a cover image are used for hiding secret information. In this paper a new technique based on pairs matching is proposed data bits of the message to be secured are arranged in ...

  • A Novel Indoor Channel Model for TVWS Communications based on Measurements 

    Authors:Hashir, Syed Muhammad; Erküçük, Serhat; Baykaş, Tunçer
    Publisher and Date:(IEEE, 2018)
    In this paper we present an indoor measurement campaign for TV white space bands inside a university building. The measurement results are compared with different indoor propagation models in the literature. We observed large estimation errors for the total path loss value from all existing models. Consequently we are proposing a new indoor propagation model for TVWS frequencies which concatenates the effects of frequency dependent path loss with penetration losses due to walls and windows. ...

  • A numerical method for frequency determination in the astable cellular neural networks with opposite-sign templates 

    Authors:Özmen, Atilla; Tander, Baran
    Publisher and Date:(IEEE, 2006)
    In this study a numerical method is proposed to determine the oscillation frequencies in the astable cellular neural networks with opposite-sign templates [1]. This method depends on the training of a multilayer perceptron that uses various template coefficients and the correspondant frequency values as inputs and outputs. First of all a frequency surface is obtained from templates and then training samples are picked from this surface in order to apply to multilayer perceptron. The effects of the ...

  • A portable high-productivity approach to program heterogeneous systems 

    Authors:Bozkuş, Zeki; Fraguela, Basilio B.
    Publisher and Date:(IEEE, 2012)
    The exploitation of heterogeneous resources is becoming increasingly important for general purpose computing. Unfortunately heterogeneous systems require much more effort to be programmed than the traditional single or even multi-core computers most programmers are familiar with. Not only new concepts but also new tools with different restrictions must be learned and applied. Additionally many of these approaches are specific to one vendor or device resulting in little portability or rapid ...

  • A Recommender Model Based on Trust Value and Time Decay Improve the Quality of Product Rating Score in E-commerce Platforms 

    Authors:Işık, Muhittin; Daǧ, Hasan
    Publisher and Date:(IEEE, 2017)
    Most of the existing products rating score algorithms do not take fake accounts and time decay of users' ratings into account when creating the list of recommendations. The trust values and the time decay of users' ratings to an item may improve the quality of product rating score in e-commerce platforms especially when it is thought that nowadays the majority of customers read the reviews before making a purchase. In this paper we first introduce the concept trust value of users by explaining its ...

  • A Simple Iterative Equalizer for Space Time Coded Multiple Antenna Systems 

    Authors:Güçlüoǧlu, Tansal
    Publisher and Date:(IEEE, 2009)
    In this paperg a simple low complexity iterative receiver for spacetime coded zSTCg transmission is proposed and the pen formance over frequencyyselective fast and quasistatic fading channels is investigatedF Simulation results show that the pery formance of the proposed structure improves with each iteraytionF Considering the practically prohibitive complexity of opytimal equalizersg the proposed iterative receiver can be more desirable in wireless systems with large number of antennasg big ...

  • A synthesis tool for the multiplierless realization of FIR-based multirate DSP systems 

    Authors:Yurdakul, Arda
    Publisher and Date:(IEEE, 2000)
    In this study a synthesis tool using a novel multirate folding technique which handles each FIR filter in a multirate DSP system as a single node is developed. A new architecture is presented for the multiplierless realization of a fold of multirate FIR filters. This synthesizer fully exploits the redundancies (i.e. `idle' and `missing' cycles) and common terms in multirate systems without sacrificing from overall system quality to produce multiplierless multirate systems. It also enables the usage ...

  • Accelerating Brain Simulations on Graphical Processing Units 

    Authors:Kayraklioglu, Engin; El-Ghazawi, Tarek A.; Bozkuş, Zeki
    Publisher and Date:(IEEE, 2015)
    NEural Simulation Tool(NEST) is a large scale spiking neuronal network simulator of the brain. In this work we present a CUDA(R) implementation of NEST. We were able to gain a speedup of factor 20 for the computational parts of NEST execution using a different data structure than NEST's default. Our partial implementation shows the potential gains and limitations of such possible port. We discuss possible novel approaches to be able to adapt generic spiking neural network simulators such as NEST ...

  • Achievable Performance of Bayesian Compressive Sensing Based Spectrum Sensing 

    Authors:Başaran, Mehmet; Erküçük, Serhat; Cirpan, Hakan Ali
    Publisher and Date:(IEEE, 2014)
    In wideband spectrum sensing compressive sensing approaches have been used at the receiver side to decrease the sampling rate if the wideband signal can be represented as sparse in a given domain. While most studies consider the reconstruction of primary user's signal accurately it is indeed more important to analyze the presence or absence of the signal correctly. Furthermore these studies do not consider the achievable lower bounds of reconstruction error and how well the selected method performs ...

  • Alternative Transducer Power Gain Expression in Broadband Matching Network Designs 

    Authors:Şengül, Metin Y.
    Publisher and Date:(IEEE, 2016)
    In this paper a reflection coefficient based transducer power gain expression has been derived which is an alternative to the impedance based expression exists in the literature. A broadband double matching problem is solved by using the derived gain expression and the obtained performance has been compared with the performance obtained via the existing expression.

  • An Efficient SAGE-based Data Detection Algorithm for OFDM Systems in the Presence of Very Fast Fading Channels 

    Authors:Dong, Zhicheng; Fan, Pingzhi; Panayirci, Erdal
    Publisher and Date:(IEEE, 2013)
    In this paper an iterative and computationally efficient data detection algorithm is proposed based on the space alternating generalized expectation maximization (SAGE) technique for orthogonal division multiplexing (OFDM) systems under fast fading channels. The proposed detector includes the original detector presented in [1] as one of its special cases. With a proper choice of its parameters simulations show that the new detector has negligible performance loss than original one in [1] with ...

  • Analysis of Extended Busy Tone Performance for Coexistence between WRAN and WLAN TVWS Networks 

    Authors:Karatalay, Onur; Erküçük, Serhat; Baykaş, Tunçer
    Publisher and Date:(IEEE, 2015)
    TV White Spaces indicate spectrum bands which were reserved for licensed terrestrial TV broadcasting and opened to unlicensed use under regulatory conditions. One important regulation which is common in all regulatory domains is no harmful interference is created to licensed devices. On the other hand interference between unlicensed devices is not regulated. As a result system designers developed new methods to improve coexistence between TVWS networks. Extended busy tone one of such methods is ...

  • Assessment of Harmonic Distortion on Distribution Feeders with Electric Vehicles and Residential PVs 

    Authors:Ceylan, Oǧuzhan; Paudyal, Sumit; Dahal, Sudarshan; Karki, Nava R.
    Publisher and Date:(IEEE, 2017)
    Power-electronic interfacing based devices such as photovoltaic (PV) panels and electric vehicles (EVs) cause voltage/current harmonic distortions on the power grid. The harmonic current profiles from EVs and PVs depend on the design of the controllers integrated to the PV inverters and EV chargers. Similarly the voltage and current harmonic distortions on a grid change throughout the day as the PV output power number of grid connected EVs and the other load pattern change. In this context we ...

  • Beacons for Indoor Positioning 

    This work aims to develop a system for the tracking and control of elderly or handicapped people in an indoor environment. We have developed both a special box using an Arduino board and a mobile application on Android to determine the location of the target based on the Bluetooth Low Energy signals transmitted by special Beacons which are placed in the area of interest. Both systems are used to determine the position of the person and to monitor any event that would cause an alert. Those events ...

  • Big Data Platform Development with a Domain Specific Language for Telecom Industries 

    Authors:Senbalci, Cuneyt; Altuntas, Serkan; Bozkuş, Zeki; Arsan, Taner
    Publisher and Date:(IEEE, 2013)
    This paper introduces a system that offer a special big data analysis platform with Domain Specific Language for telecom industries. This platform has three main parts that suggests a new kind of domain specific system for processing and visualization of large data files for telecom organizations. These parts are Domain Specific Language (DSL) Parallel Processing/Analyzing Platform for Big Data and an Integrated Result Viewer. hi addition to these main parts Distributed File Descriptor (DFD) is ...