Browsing by Publisher "Institute of Electrical and Electronics Engineers Inc."
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Item A new robust 'integral of sign of error' feedback controller with adaptive compensation gain(Institute of Electrical and Electronics Engineers Inc., 2013) Bidikli B.; Tatlicioglu E.; Bayrak A.; Zergeroglu E.In this paper, a new robust integral of signum of error (RISE) feedback type controller is designed for a class of uncertain nonlinear systems. Unlike the previous versions of RISE feedback type controllers, the proposed controller does not require prior knowledge of upper bounds of the vector containing the uncertainties of the dynamical system plus desired system dynamics (and their derivatives) for the control gain selection. The aforementioned enhancement is made possible via the design of a time-varying compensation gain as opposed to a constant gain used in previous RISE feedback type controllers. Asymptotic stability of the error signals and the boundedness of the closed-loop system signals are ensured via Lyapunov based arguments. Numerical simulation studies are presented to illustrate the viability of the proposed method. ©2013 IEEE.Item Observer based output feedback tracking control of dynamically positioned surface vessels(Institute of Electrical and Electronics Engineers Inc., 2013) Bidikli B.; Tatlicioglu E.; Zergeroglu E.This work concentrates on tracking control of dynamically positioned surface vessels where only position and orientation measurements are available. Specifically, in order to remove the velocity measurement dependency of the control formulation, we designed a nonlinear, model-free observer which enables the observer-controller couple to achieve asymptotic tracking. Stability of the closed-loop system is ensured by Lyapunov-based arguments. Simulation studies are also presented to illustrate the effectiveness of the proposed method. © 2013 AACC American Automatic Control Council.Item State dependent sliding sectors for nonlinear systems with nonlinear sliding surfaces(Institute of Electrical and Electronics Engineers Inc., 2013) Ozcan S.; Salamci M.U.; Birinci B.E.The paper suggests a method to design sliding sector control for a class of nonlinear systems in which the system trajectories are kept around a nonlinear sliding surface. The sliding surface is designed by using State Dependent Riccati Equations where Algebraic Riccati Equations are solved for frozen system states. The solutions are used to create the nonlinear (or state dependent) sliding surface around which state dependent sliding sectors are formed. The nonlinear system trajectories are forced inside the sliding sector by using the so-called sliding sector control. The method is illustrated by applying it to a nonlinear inverted pendulum model. © 2013 AACC American Automatic Control Council.Item A numerical analysis of thermal management schemes of a LED array in TFT TV(Institute of Electrical and Electronics Engineers Inc., 2014) Mermer O.; Nil M.; Akgul M.B.This paper aims to perform the numerical analysis and to investigate thermal characteristics of the LED backlight TFT TV according to thermal design parameters. Natural convective cooling of a LED array system used TFT TV is considered in this study. Numerical computations are carried out for horizontal and vertical orientations of the LED array. The effects of the PCB materials on the temperature distribution are discussed in detail. It is found that the maximum temperature of the LED packages significantly decreases by the horizontal orientation of the LED array in TFT based television. In addition, ceramic based PCB materials having high thermal conductivity such as A1N present better thermal performance than that of metal based PCB materials. © 2014 IEEE.Item A survey of SIP authentication and key agreement schemes(Institute of Electrical and Electronics Engineers Inc., 2014) Kilinc H.H.; Yanik T.We present a survey of authentication and key agreement schemes that are proposed for the SIP protocol. SIP has become the center piece for most VoIP architectures. Performance and security of the authentication and key agreement schemes are two critical factors that affect the VoIP applications with large number of users. Therefore, we have identified, categorized and evaluated various SIP authentication and key agreement protocols according to their performance and security features. Although the performance is inversely proportional to the security features provided in general, we observed that there are successful schemes from both the performance and security viewpoint. © 2014 IEEE.Item Hybrid imbalanced data classifier models for computational discovery of antibiotic drug targets(Institute of Electrical and Electronics Engineers Inc., 2014) Kocyigit Y.; Seker H.Identification of drug candidates is an important but also difficult process. Given drug resistance bacteria that we face, this process has become more important to identify protein candidates that demonstrate antibacterial activity. The aim of this study is therefore to develop a bioinformatics approach that is more capable of identifying a small but effective set of proteins that are expected to show antibacterial activity, subsequently to be used as antibiotic drug targets. As this is regarded as an imbalanced data classification problem due to smaller number of antibiotic drugs available, a hybrid classification model was developed and applied to the identification of antibiotic drugs. The model was developed by taking into account of various statistical models leading to the development of six different hybrid models. The best model has reached the accuracy of as high as 50% compared to earlier study with the accuracy of less than 1% as far as the proportion of the candidates identified and actual antibiotics in the candidate list is concerned. © 2014 IEEE.Item Ensemble methods for opinion mining; [Görüş Madenciliʇinde Siniflandirici Topluluklari](Institute of Electrical and Electronics Engineers Inc., 2015) Onan A.; Korukoglu S.Opinion mining is an emerging field which uses computer science methods to extract subjective information, such as opinion, emotion, and attitude inherent in opinion holder's text. One of the major issues in opinion mining is to enhance the predictive performance of classification algorithm. Ensemble methods used for opinion mining aim to obtain robust classification models by combining decisions obtained by multiple classifier training, rather than depending on a single classifier. In this study, the comparative performance of opinion mining datasets on Bagging, Dagging, Random Subspace and Adaboost ensemble methods with five different classifiers and six different data representation schemes are presented. The experimental results indicate that ensemble methods can be used for building efficient opinion mining classification methods. © 2015 IEEE.Item Simulation optimization approach for customer centric lot streaming problem in job shops(Institute of Electrical and Electronics Engineers Inc., 2015) Güçdemir H.; Selim H.In today's competitive market, time based strategies become important to gain sustainable competitive advantage. Therefore, manufacturing companies need advanced production planning and control (PPC) techniques in order to respond quickly to demand. In addition, customer centricity becomes the key success factor for manufacturing industry. In this regard, integration of customer relationship management (CRM) and PPC decisions is necessary in order to satisfy customers with efficient use of manufacturing capabilities. The aim of this study is to analyze the effect of customer centricity on lot streaming (LS) problem. To this aim, LS problem in job shop environment is dealt with in this study, and traditional LS problem is extended by including preferences of multiple customer segments. It is intended to find a lot splitting policy for each customer segment-product type combination. The objective function is defined as minimization of total weighted percentage deviation from the preferences of customer segments. Simulation optimization approach is used to solve the problem. The results reveal that the proposed approach supports order splitting decisions, and can effectively be used in practice. © 2015 IEEE.Item Imaging multiple objects with time-reversed FDTD method at microwave range(Institute of Electrical and Electronics Engineers Inc., 2015) Bardak C.; Saed M.; Tas̈kln S.A simulation technique is presented for imaging multiple objects in microwave region. The proposed technique is based on the time-reversed finite-difference time-domain method (FDTD-TR) in three dimensions. Using this technique, not only the locations of objects but also their detailed images can be obtained. The method is capable of imaging hidden objects with transmission as well as reflection imaging modalities in the nearfield and far-field. The proposed technique is computationally efficient due to using a much smaller data set compared to conventional FDTD-TR imaging techniques where the entire time span of the captured data is reversed. The method was validated using experimental results as well as simulations. © 2015 IEEE.Item Landing sequencing modelling with fuzzy logic: Opportunistic approach for unmanned aerial systems(Institute of Electrical and Electronics Engineers Inc., 2016) Oren A.; Kocyigit Y.From the beginning of 21th century, the quantities and types of Unmanned Aerial Systems (UAS) have grown enormously and they become to boost substitution for the manned systems. UAS are creating advancement with a massive potential to change military operations and also enabling the new civilian applications. The vital issue for the airspace designers and managers is how to integrate manned and unmanned systems to the interoperability airspace. It is global arrangement that UAS operation in the integrated airspace must meet in any operational standards, procedures and safety issues as manned aircraft. For today, Air Traffic Management (ATM) is a dynamic and integrated environment including both manned and unmanned systems. Air Traffic Control (ATC) systems have the obligation to sustain an efficient and safe airspace utilization of manned and unmanned systems together. On the other hand, tendency for civilian and military applications about future is substituting unmanned aerial systems for manned aerial systems. In this paper, we present an analytic approach for UAS landing sequencing modelling in the dynamic airspace including different aerodynamic specifications or mission types for both military and civilian UAS via fuzzy logic modelling. During the designing model, the MATLAB Fuzzy FIS (Fuzzy Inference System) is used with realistic data and the user friendly interface is created via MATLAB/GUI. © 2016 IEEE.Item Designing of a fuzzy controller for grid connected photovoltaic system's converter and comparing with PI controller(Institute of Electrical and Electronics Engineers Inc., 2016) Basaran K.; Cetin N.S.The design criteria of PV cell, DC/DC converter and grid connected DC/AC inverter which belong to the photovoltaic system are determined and Simulink models are established in this study. The control of DC/DC converter and DC/AC inverter is ensured by using fuzzy logic and PI control. The results of fuzzy logic and PI control were compared. It was seen in the result of simulation that fuzzy logic control is more efficient than PI control, output current of inverter has sinusoidal waveform and it follows the waveform of line voltage with same phase angle. © 2016 IEEE.Item An analogy between womb and home for supporting the aspects of smart cities(Institute of Electrical and Electronics Engineers Inc., 2016) Akaslan D.; Taşkln S.A number of utilities should be delivered to householders to fulfil certain requirements via disparate infrastructures associated with production, distribution and consumption. Since the major of these utilities require enormous expenditure and bring complexity, undesired interactions and difficulty in installation, maintenance and management are always encountered. To deal with these issues, a number of models for the single-utility product have been proposed such as the blood of city and the umbilical cording vision. In this study, we propose a model by drawing an analogy between a womb and home so as to supply all services through one utility product. To form the mental picture of the analogy, the life cycle from the birth to the death are taken into consideration in four aspects: foetus as the householder, placenta as the security, umbilical cording as the networking, and amniotic fluid as the stabilizer of the indoor temperature. © 2016 IEEE.Item New memristor emulator circuit using OTAs and CCIIs(Institute of Electrical and Electronics Engineers Inc., 2016) Sözen H.; Çam U.In this paper, a new memristor emulator circuit is proposed. It is realized by operational transconductance amplifiers (OTAs) and second generation current conveyors (CCIIs). A mathematical model to describe the behavior of presented circuit is derived. Memristance value of the emulator circuit is adjustable by means of a simple change of transconductance parameter (gm) of operational transconductance amplifier in the emulator circuit, amplitude and frequency value of applied voltage across terminals of memristor emulator. Frequency dependent pinched hysteresis loop in the current versus voltage plane holds up to 5 kHz. The breadboard experiment of proposed emulator circuit is built by using CA3080 and AD844 ICs for transconductance amplifier and second generation current conveyor respectively. The results of SPICE simulation and experimental test are given to verify the theoretical analyses. The presented emulator circuit can be used in real world memristor circuit applications such as chaotic systems, programmable analog circuits. © 2015 Chamber of Electrical Engineers of Turkey.Item An experimental study of a piezoelectrically actuated touch screen(Institute of Electrical and Electronics Engineers Inc., 2017) Sari G.; Akgül M.B.; Kirişken B.; Ak A.F.; Akiş A.A.An audiovisual feedback is used on touch screens in portable electronic devices. When these devices are used in noisy and distracting environments, suitable available feedback methods is severely inadequate and the availability of the device severely reduced. For these reasons, touch screen technology has become a popular recently. These panels used in many sectors such as watches, cars, mobile devices, aerospace. Touch screens, which provide tactile feedback to the user, are activated using solenoid actuators, coil-type actuators or vibration motors. The use of evolving piezoelectric vibrators has attracted considerable attention in recent years to obtain high-resolution tactile feedback. Their higher bandwidth helps create more user-perceivable haptic effects. In this work, we experimented to observe the effect of the piezo vibrator on the screen. As a result, the various types of tactile feedback functions will be developed on the screen and compared. The best vibration functions depending on the settings are obtained through experiments. © 2017 IEEE.Item A K-medoids based clustering scheme with an application to document clustering(Institute of Electrical and Electronics Engineers Inc., 2017) Onan A.Clustering is an important unsupervised data analysis technique, which divides data objects into clusters based on similarity. Clustering has been studied and applied in many different fields, including pattern recognition, data mining, decision science and statistics. Clustering algorithms can be mainly classified as hierarchical and partitional clustering approaches. Partitioning around medoids (PAM) is a partitional clustering algorithms, which is less sensitive to outliers, but greatly affected by the poor initialization of medoids. In this paper, we augment the randomized seeding technique to overcome problem of poor initialization of medoids in PAM algorithm. The proposed approach (PAM++) is compared with other partitional clustering algorithms, such as K-means and K-means++ on text document clustering benchmarks and evaluated in terms of F-measure. The results for experiments indicate that the randomized seeding can improve the performance of PAM algorithm on text document clustering. © 2017 IEEE.Item Twitter fake account detection(Institute of Electrical and Electronics Engineers Inc., 2017) Erşahin B.; Aktaş O.; Kilmç D.; Akyol C.Social networking sites such as Twitter and Facebook attracts millions of users across the world and their interaction with social networking has affected their life. This popularity in social networking has led to different problems including the possibility of exposing incorrect information to their users through fake accounts which results to the spread of malicious content. This situation can result to a huge damage in the real world to the society. In our study, we present a classification method for detecting the fake accounts on Twitter. We have preprocessed our dataset using a supervised discretization technique named Entropy Minimization Discretization (EMD) on numerical features and analyzed the results of the Naïve Bayes algorithm. © 2017 IEEE.Item Development of electromagnetic field system for providing wound healing on created wound model rat skin and sensor application; [Sicąn Derisinde Olusturulan Yara Modeli Üzerinde Iyilesme Saglanmasi için Elektromanyetik Alan Sistemi Gelistirilmesi ve Sensör Uygulamasi](Institute of Electrical and Electronics Engineers Inc., 2017) Gumusay M.; Gulbagca F.; Aydemir I.; Saygili S.; Kaya A.; Tuglu M.I.Electromagnetic field (EMF) radiation are formed by the acceleration of electric charge. Electric charges produce electric and magnetic energy in space when they move. These waves have different frequencies and wavelengths and when they interact with an object they can be refracted, reflected or absorbed. When a suitable frequency and waveform EM signal is applied to the target tissue with the help of a coil or applicator physiological effects will occur at the cellular size. Today studies revealed significant molecular mechanisms occurring during wound healing. Non-ionizing part of the EM spectrum is low-frequency electromagnetic fields are used as adjunct therapy in soft tissue injuries. In this study, the main goal is development of systems which will give better results compared with conventional treatment methods taking into account the effect on rat skin. To achieve this, some improvements in output power, increased gain, versatility, easy adjustments are provided for the spiral and planar antenna-applicator design. © 2016 The Chamber of Turkish Electrical Engineers.Item Numerical analysis of vibrating touch screen actuated by piezo elements(Institute of Electrical and Electronics Engineers Inc., 2017) Ak A.F.; Sari G.; Akgül M.B.; Kirişken B.; Akiş A.A.Audiovisual feedback generally is used on touch screens on portable electronic devices, which are frequently used in daily life. Tactile feedback is one of the issues that have recently gained importance in this technology. Tactile feedback occurs by stimulating the nerves at the fingertip by moving the touch screen. In this study, we have determined the vibration characteristics of touchscreens made from different materials used in the sector. The finite element method is employed to obtain the vibration modes of the screen. In addition to, the effects of the materials of piezo, applied voltage, the number of the piezo patches are investigated to produce the best vibration function and graphically are presented. © 2017 IEEE.Item A smart approach on collecting working condition data from home appliances under the field test(Institute of Electrical and Electronics Engineers Inc., 2017) Yildirim I.; Taskin S.This study presents management of the data that are taken from the home appliances which are in the field test process. Field test process means collecting the data from the device by sensors, the measurement from environment, then evaluation of this information. This information depends on climate, altitude, user profile etc. Major application area of this study is home appliances sets and their domestic field test process. Also, this smart approach can be applied to any system including any electrical equipment in smart grid. Only 2 different requirements should be covered. (i) Device Under Test (DUT) should work with the specialized test box to send working condition data and environmental measurements. (ii) GSM network should be alive in field test location. This study shows a new smart approach which relies on sending the field test data and environmental conditions over the GSM. The selection reason of GSM communication protocol in this study is the coverage percentage of this protocol is wider than others. © 2017 IEEE.Item The effect of electro magnetic fields on cell behaviour; [Elektro Manyetik Alanlarin Hücre Davranisina Etkisi](Institute of Electrical and Electronics Engineers Inc., 2017) Tuglu M.I.; Gulbagca F.; Sal D.H.; Saygili S.; Sonmez P.K.; Aydemir I.; Ozkut M.; Ozturk S.; Gumusay M.; Kaya A.; Keskin N.The biologic effects of electomagnetic fields application on medical field has been increased. Their effect on medical treatment depends on cell behaviour which can be observed by in vivo and in vitro studies. Their effect on the stem cells and the cell lines and the organs of experimental animals with morphological alterations are helpful to understand cell behaviour. The behaviour of the cells can be analyse at ultrastructural level by scaning electron microscopy. Application of electomagnetic fields cause increase of proliferation, migration and improvement of wound healing with beneficial effects while they cause oxidative stress and cell death including apoptosis for cancer cells in different types of cell line. The minimal side effect with maximum beneficial treatment of these products suggest that they could be very useful for clinical trials. © 2016 IEEE.