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Articles 6751 - 6780 of 10319
Full-Text Articles in Physical Sciences and Mathematics
Synthesis And Antioxidant And Antimicrobial Evaluation Of Novel 4-Substituted-1h-1,2,4-Triazole Derivatives, Sultan Baytaş, Evi̇n Kapçak, Tülay Çoban, Hati̇ce Özbi̇lge
Synthesis And Antioxidant And Antimicrobial Evaluation Of Novel 4-Substituted-1h-1,2,4-Triazole Derivatives, Sultan Baytaş, Evi̇n Kapçak, Tülay Çoban, Hati̇ce Özbi̇lge
Turkish Journal of Chemistry
A series of 4-benzyl/phenyl-3-(1-methyl-1H-indole-2-yl)-1H- 1,2,4-triazole-5(4H)-thione (4a,b) and 2-{4-[benzyl/phenyl-5- (substitutedbenzylthio)]-4H-1,2,4-triazole-3-yl}-1-methyl-1H-indole derivatives (5a-p) were synthesized and evaluated for their in vitro scavenging of DPPH and superoxide radical, and lipid peroxidation inhibition effects as well as their antimicrobial properties. DPPH radical scavenging capacity was found to be equipotent with BHT and found in compounds containing 1,2,4-triazole-5(4H)-thione moiety (4a,b). With regard to antimicrobial properties, compound 5k showed slight antimicrobial activity against all the test microorganisms.
Mwcnt/Nano-Zro_2 As A New Solid Phase Extractor: Its Synthesis, Characterization, And Application To Atomic Absorption Spectrometric Determination Of Lead, Orhan Murat Kalfa, Özcan Yalçinkaya, Ali̇ Rehber Türker
Mwcnt/Nano-Zro_2 As A New Solid Phase Extractor: Its Synthesis, Characterization, And Application To Atomic Absorption Spectrometric Determination Of Lead, Orhan Murat Kalfa, Özcan Yalçinkaya, Ali̇ Rehber Türker
Turkish Journal of Chemistry
Nanoscale ZrO_2 was synthesized on a multiwall carbon nanotube (MWCNT) and designed as a new solid phase extractor for metal ion preconcentration. The characterization of the synthesized material was achieved by transmission electron microscope (TEM) and X-ray diffraction (XRD). Then the new nanoscale material was applied to preconcentration of lead(II) from various matrices. Different experimental factors including pH of the sample solution, sample volume, flow rate of the sample solution, and volume and concentration of the eluent for the preconcentration step were examined. The effect of interfering ions on the recovery of the lead(II) was also investigated. The recovery of …
Synthesis And Structural And Electrochemical Characterization Of Novel Macrocyclic Vic-Dioxime Ligand And Its Mononuclear Transition And Nontransition Metal Complexes, Pervi̇n Deveci̇, Bi̇lge Taner, Zeynel Kiliç, Ali̇ Osman Solak, Emi̇ne Özcan
Synthesis And Structural And Electrochemical Characterization Of Novel Macrocyclic Vic-Dioxime Ligand And Its Mononuclear Transition And Nontransition Metal Complexes, Pervi̇n Deveci̇, Bi̇lge Taner, Zeynel Kiliç, Ali̇ Osman Solak, Emi̇ne Özcan
Turkish Journal of Chemistry
The reaction of N-(4-aminophenyl)aza-15-crown-5 (1) with anti-chlorophenylglyoxime (2) produces a novel azacrown ether containing vic-dioxime, N-(4-aminophenyl)aza-15-crown-5-phenylglyoxime (LH_2). LH_2 reacts with Ni(II), Cu(II), Co(II), Cd(II), and Zn(II) ions to yield the mononuclear transition and nontransition metal complexes [M(LH)_2] (M = Ni and Cu), [M(LH)_2(H_2O)_2] (M = Co), and [M(LH)(H_2O)(Cl)] (M = Cd and Zn). The structural features of LH_2 were studied using several techniques including elemental analysis, Fourier transform infrared spectroscopy (FT-IR), ultraviolet visible (UV-Vis), mass spectrometry (MS), 1-dimensional (1D) ^1H-NMR and ^{13}CNMR, distortionless enhancement by polarization transfer (DEPT) 2-dimensional (2D) heteronuclear single-quantum coherence (HSQC), and heteronuclear multiple-bond correlation (HMBC) techniques. …
Load Sharing Based On Moving Roles In Multiagent Systems, Şebnem Bora, Ali̇ Murat Ti̇ryaki̇, Oğuz Di̇kenelli̇
Load Sharing Based On Moving Roles In Multiagent Systems, Şebnem Bora, Ali̇ Murat Ti̇ryaki̇, Oğuz Di̇kenelli̇
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we present a load-sharing approach based on the refactoring of agents. According to our approach, the role(s) that makes an agent overloaded is identified and transferred to less loaded agents. The excess workload of this heavily loaded agent is then transferred to the new agent. This approach defines a new agent, called the ``monitor agent,'' which monitors the workload of agents in the organization and decides about the refactoring of the agents. The monitor agent uses the platform ontology, which explicitly describes the components of the agent organization, including agents and their roles, plans, and workloads. This …
A Comparative Study Of Blind And Nonblind Trainings In A Single-Carrier Wimax (Ieee 802.16-2004) Radio, Ali̇ Özen
Turkish Journal of Electrical Engineering and Computer Sciences
Experimental and theoretical bit error rate performance evaluations of blind and nonblind training techniques are obtained by using a single-carrier WiMAX (IEEE 802.16-2004) radio for high-order quadrature amplitude modulation channels. Instead of using a certain type of channel profile, this study concentrates on true frequency-selective Rayleigh fading channels and also evaluates the fast fading scenario of Rayleigh channels in a real-time WiMAX radio environment around 3.5 GHz. The popular least mean squares (LMS) learning algorithm and constant modulus learning algorithm (CMA) are used as benchmarks in an investigation of nonblind and blind trainings, namely recursive least squares (RLS), modified-CMA, normalized-CMA, …
Optimization Of Pilot Tones Using Differential Evolution Algorithm In Mimo-Ofdm Systems, Muhammet Nuri̇ Seyman, Necmi̇ Taşpinar
Optimization Of Pilot Tones Using Differential Evolution Algorithm In Mimo-Ofdm Systems, Muhammet Nuri̇ Seyman, Necmi̇ Taşpinar
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we propose a differential evolution (DE) algorithm for optimizing the placement and power of the pilot tones that are utilized by a least square (LS) algorithm for channel estimation in multiple-input and multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) systems. Computer simulations demonstrated that the performance of the LS algorithm was increased by optimizing the pilot tones with the DE algorithm instead of locating them orthogonally. We used the upper bound of the mean square error (MSE) as a fitness function of the DE algorithm for optimization tasks. With the use of an upper bound, it is not necessary …
An Improved Fastslam Framework Using Soft Computing, Ramazan Havangi, Mohammad Ali Nekoui, Mohammad Teshnehlab
An Improved Fastslam Framework Using Soft Computing, Ramazan Havangi, Mohammad Ali Nekoui, Mohammad Teshnehlab
Turkish Journal of Electrical Engineering and Computer Sciences
FastSLAM is a framework for simultaneous localization and mapping (SLAM) using a Rao-Blackwellized particle filter. However, FastSLAM degenerates over time. This degeneracy is due to the fact that a particle set estimating the pose of the robot loses its diversity. One of the main reasons for losing particle diversity in FastSLAM is sample impoverishment. In this case, most of the particle weights are insignificant. Another problem of FastSLAM relates to the design of an extended Kalman filter (EKF) for the landmark position's estimation. The performance of the EKF and the quality of the estimation depend heavily on correct a priori …
A Video Encoder Design Combining Edge-Adaptive Lifting And Scalable Block-Matching With Motion Compensation, Sedat Telçeken, Ömer Nezi̇h Gerek
A Video Encoder Design Combining Edge-Adaptive Lifting And Scalable Block-Matching With Motion Compensation, Sedat Telçeken, Ömer Nezi̇h Gerek
Turkish Journal of Electrical Engineering and Computer Sciences
This study aimed to achieve video compression by using a novel lifting-based hybrid encoder that also uses motion compensation. The proposed encoder separates video frames into temporal groups, within which certain frames are selected for producing temporal and spatial predictions over the rest of the frames. The predictions utilize spatiotemporal lifting together with motion compensation. The combination of spatial information with temporal changes is inspired from the idea of edge-adaptive lifting, which alters prediction directions in images. A further incorporation of well-known block-matching methods with different levels was observed to improve the performance. To provide the first compression results, unpredicted …
Mathematical Modeling And Vertical Flight Control Of A Tilt-Wing Uav, Kaan Taha Öner, Ertuğrul Çeti̇nsoy, Efe Sirimoğlu, Cevdet Hançer, Mustafa Ünel, Mahmut Faruk Akşi̇t, Kayhan Gülez, İlyas Kandemi̇r
Mathematical Modeling And Vertical Flight Control Of A Tilt-Wing Uav, Kaan Taha Öner, Ertuğrul Çeti̇nsoy, Efe Sirimoğlu, Cevdet Hançer, Mustafa Ünel, Mahmut Faruk Akşi̇t, Kayhan Gülez, İlyas Kandemi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a mathematical model and vertical flight control algorithms for a new tilt-wing unmanned aerial vehicle (UAV). The vehicle is capable of vertical take-off and landing (VTOL). Due to its tilt-wing structure, it can also fly horizontally. The mathematical model of the vehicle is obtained using Newton-Euler formulation. A gravity compensated PID controller is designed for altitude control, and three PID controllers are designed for attitude stabilization of the vehicle. Performances of these controllers are found to be quite satisfactory as demonstrated by indoor and outdoor flight experiments.
Design Parameters And Uncertainty Bound Estimation Functions For Adaptive-Robust Control Of Robot Manipulators, Recep Burkan
Design Parameters And Uncertainty Bound Estimation Functions For Adaptive-Robust Control Of Robot Manipulators, Recep Burkan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a parameter and uncertainty bound estimation functions for adaptive-robust control of robot manipulators are developed. A Lyapunov function is defined and parameters and uncertainty bound estimation functions are developed based on the Lyapunov function. Thus, stability of an uncertain system is guaranteed and uniform boundedness of the tracking error is achieved. As distinct from previous parameter and bound estimation laws, the parameters and uncertainty bounds are updated as a function of a combination of trigonometric function depending on robot parameters and tracking error. Based on the same Lyapunov function, a robust control law is also defined and …
Analysis Of Orthogonal Matching Pursuit Based Subsurface Imaging For Compressive Ground Penetrating Radars, Mehmet Ali̇ Çağri Tuncer, Ali̇ Cafer Gürbüz
Analysis Of Orthogonal Matching Pursuit Based Subsurface Imaging For Compressive Ground Penetrating Radars, Mehmet Ali̇ Çağri Tuncer, Ali̇ Cafer Gürbüz
Turkish Journal of Electrical Engineering and Computer Sciences
It is shown that compressive sensing (CS) theory can be used for subsurface imaging in stepped frequency ground penetrating radars (GPR), resulting in robust sparse images, using fewer measurements. Although the data acquisition time is decreased by CS, the computational complexity of the minimization based imaging algorithm is too costly, which makes the algorithm useless, especially for extensive discretization or 3D imaging. In this paper, a greedy alternative, orthogonal matching pursuit (OMP) is used for imaging subsurface and its performance under various conditions is compared to CS imaging method. Results show that OMP could reconstruct sparse signals robustly as well …
A Hybrid Approach For Power Quality Monitoring, Okan Özgönenel, Ümi̇t Kemaletti̇n Terzi̇, Abdesh Khan
A Hybrid Approach For Power Quality Monitoring, Okan Özgönenel, Ümi̇t Kemaletti̇n Terzi̇, Abdesh Khan
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a novel hybrid approach for detection of power quality (PQ) disturbances. The proposed hybrid algorithm is based on applications of principle component analysis, discrete wavelet transform, and fast Fourier transform on voltage and current waveforms. The proposed PQ monitoring (PQM) software uses 3-phase voltage and current signals in order to detect possible power disturbances such as voltage sag, flicker, harmonics, transients, DC component, and electromagnetic interference. The test results demonstrate the potential of the proposed hybrid technique for PQM andPQ assessment.
A Pseudo Spot Price Of Electricity Algorithm Applied To Environmental Economic Active Power Dispatch Problem, Celal Yaşar
A Pseudo Spot Price Of Electricity Algorithm Applied To Environmental Economic Active Power Dispatch Problem, Celal Yaşar
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, an environmental economic active power dispatch problem is transformed into an optimization problem with a single-objective function by applying the weighted sum method (WSM) and the conic scalarization method (CSM). A pseudo spot price of electricity algorithm (PSPA) is used to solve the transformed problem. This is demonstrated on an example problem, which is a lossy electrical power system having only thermal units The WSM and CSM methods are applied to the example problem, and the weight factor values of these methods is increased from 0 to 1 by a step size of 0.1. For each possible …
Improvement Of Smart Card Based Password Authentication Scheme For Multiserver Environments, Zuowen Tan
Improvement Of Smart Card Based Password Authentication Scheme For Multiserver Environments, Zuowen Tan
Turkish Journal of Electrical Engineering and Computer Sciences
In multiserver (MS) environments, it is preferable for a remote user to login to different service provider servers by keying in the same password. Recently, Wang et al. proposed an improvement on the dynamic identity-based smart card authentication scheme of Liao and Wang for MS environments. Sandeep et al. improved the dynamic identity-based smart card authentication scheme of Hsiang et al. for MS architecture. However, we found that the schemes of Wang et al. and Sandeep et al. failed to provide service provider server authentication, perfect forward security, and login scalability. In addition, the scheme of Sandeep et al. was …
Vibration Analysis Of Base Structure On Sins Using Pzt Actuators, Bin Zheng, Jianfeng Yang
Vibration Analysis Of Base Structure On Sins Using Pzt Actuators, Bin Zheng, Jianfeng Yang
Turkish Journal of Electrical Engineering and Computer Sciences
A steel plate bonded with lead zirconate titanate (PZT) actuators was studied on the basis of finite element methods (FEMs). The damping amplitudes of this plate bonded with PZT actuators were obtained at different locations and under different control conditions by analyzing the distribution of the PZT plate's strain tensor in the first 4 modes. Furthermore, to reduce the unwanted disturbance and mitigate the errors from sensors, a base structure of the missile's strapdown inertial navigation system (SINS) is also proposed. The results show that the vibration control can be enhanced by increasing the number of the PZT actuators bonded. …
Voltage Stability Via Energy Function Analysis On Reduced Order Model Of Power System, Ahmet Çi̇fci̇, Yilmaz Uyaroğlu, Mehmet Ali̇ Yalçin
Voltage Stability Via Energy Function Analysis On Reduced Order Model Of Power System, Ahmet Çi̇fci̇, Yilmaz Uyaroğlu, Mehmet Ali̇ Yalçin
Turkish Journal of Electrical Engineering and Computer Sciences
A power system is a typical nonlinear dynamical system and voltage stability is an important subject of power system stability. This paper describes the use of the variable gradient method in a reduced order model of a single-machine infinite-bus power system. Additionally, the system's Lyapunov (energy) function is created and thus the system's energy level changes' effects on the system's stability are shown using the MACSYMA program. The Lyapunov function allows the determination of stability for nonlinear systems without the need to find exact solutions.
A Novel Structure To Enhance Magnetic Force And Velocity In Tubular Linear Reluctance Motor, Ali Mosallanejad, Abbas Shoulaie
A Novel Structure To Enhance Magnetic Force And Velocity In Tubular Linear Reluctance Motor, Ali Mosallanejad, Abbas Shoulaie
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a novel design for a tubular linear reluctance motor (TLRM) has been developed. This paper presents a novel structure to enhance magnetic force and velocity in a TLRM. The new structure is accomplished through some changes in a TLRM, which results in a step winding structure. Comparing the proposed motor and the typical motor performances, it is proven that the proposed motor has better performance. For dynamic modeling of the proposed TLRM and to obtain the motor output characteristics, the method used for inductance profile calculation is described. The performance improvements in the proposed motor are evaluated …
A Novel Motor Speed Calculation Method Using Square Wave Speed Sensor Signals Via Fast Fourier Transform, Hayri̇ Arabaci, Osman Bi̇lgi̇n
A Novel Motor Speed Calculation Method Using Square Wave Speed Sensor Signals Via Fast Fourier Transform, Hayri̇ Arabaci, Osman Bi̇lgi̇n
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a novel motor speed measurement method and experimental results using the fast Fourier transform (FFT). Motor speed is obtained using the square wave output signal of a speed sensor. In the proposed method, the speed can be measured in a wide range, and transient speed changes can also be clearly observed. The experiments were conducted during start-up and in steady state. The sampled speed data were transformed to frequency spectrums using the FFT. The frequency, which corresponds to the maximum amplitude in the spectrum, was used to calculate the motor speed. The test results show that the …
Broken Rotor Bar Fault Detection In Inverter-Fed Squirrel Cage Induction Motors Using Stator Current Analysis And Fuzzy Logic, Mehmet Akar, İlyas Çankaya
Broken Rotor Bar Fault Detection In Inverter-Fed Squirrel Cage Induction Motors Using Stator Current Analysis And Fuzzy Logic, Mehmet Akar, İlyas Çankaya
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the implementation of broken rotor bar fault detection in an inverter-fed induction motor using motor current signal analysis (MCSA) and prognosis with fuzzy logic. Recently, inverter-fed induction motors have become very popular because of their adjustable speed drive. They have been used in many vital control applications such as rolling mills, variable speed compressors, pumps, and fans. The condition monitoring of these motors can significantly reduce the cost of maintenance in the early detection of faults. In this study, MCSA is applied to an inverter-fed induction motor to detect broken rotor bar faults. The diagnosis of a …
Abstract Feature Extraction For Text Classification, Göksel Bi̇ri̇ci̇k, Banu Di̇ri̇, Ahmet Coşkun Sönmez
Abstract Feature Extraction For Text Classification, Göksel Bi̇ri̇ci̇k, Banu Di̇ri̇, Ahmet Coşkun Sönmez
Turkish Journal of Electrical Engineering and Computer Sciences
Feature selection and extraction are frequently used solutions to overcome the curse of dimensionality in text classification problems. We introduce an extraction method that summarizes the features of the document samples, where the new features aggregate information about how much evidence there is in a document, for each class. We project the high dimensional features of documents onto a new feature space having dimensions equal to the number of classes in order to form the abstract features. We test our method on 7 different text classification algorithms, with different classifier design approaches. We examine performances of the classifiers applied on …
Observer Path Design By Imitation Of Competing Constraints For Bearing Only Tracking, Ridvan Gürcan, Mesut Kartal
Observer Path Design By Imitation Of Competing Constraints For Bearing Only Tracking, Ridvan Gürcan, Mesut Kartal
Turkish Journal of Electrical Engineering and Computer Sciences
In the bearing only tracking (BOT) problem the observer tries to estimate the position of the target. The observer maneuver is a requirement to guarantee the uniqueness of the estimation. Determining an observer maneuver for BOT is a difficult problem due to its nonlinear nature. This paper proposes a new method that combines the reference BOT scenarios as a priori knowledge with the incoming bearing measurements to obtain an observer maneuver in a generic optimization framework. The use of a priori knowledge makes the observer maneuver design more realistic. The maneuver recommendation process uses the imitation of competing constraints. In …
On The Degradation Of Ota-C--Based Cmos Low-Power Filter Circuits For Biomedical Instrumentation, Yasi̇n Özçelep, Ayten Kuntman, Hulusi̇ Hakan Kuntman
On The Degradation Of Ota-C--Based Cmos Low-Power Filter Circuits For Biomedical Instrumentation, Yasi̇n Özçelep, Ayten Kuntman, Hulusi̇ Hakan Kuntman
Turkish Journal of Electrical Engineering and Computer Sciences
In this work, we propose a degraded transistor-based circuit degradation simulation method to investigate the degradation effect in complementary metal-oxide semiconductor (CMOS) biomedical devices. The method is demonstrated on an operational transconductance amplifier and capacitor (OTA-C)-based CMOS filter structure. First, we simulate the degradation of the symmetrical CMOS OTA by determining the degraded transistors in the structure. The simulation results are compared with the experimental results of our previous study. First- and second-order low-pass filter degradations are also simulated to demonstrate the accuracy of the proposed method. Finally, the degradation in the electroencephalogram band-pass filter and its effect on the …
Improved Computerized Evaluation Of Abdominal Aortic Aneurysm, Semi̇h Utku, Hulusi̇ Baysal, Reyat Yilmaz, Aytaç Gülcü, Recep Alp Kut, Ahmet Yi̇ği̇t Göktay
Improved Computerized Evaluation Of Abdominal Aortic Aneurysm, Semi̇h Utku, Hulusi̇ Baysal, Reyat Yilmaz, Aytaç Gülcü, Recep Alp Kut, Ahmet Yi̇ği̇t Göktay
Turkish Journal of Electrical Engineering and Computer Sciences
Accurate measurements of arterial anatomy are emerging as the most important determinants of endovascular abdominal aneurysm repair. It is quite difficult to define and measure arterial anatomy features quantitatively due to the complex structure of the aneurysm and insufficient visual feedback. During decision making, to assist operators in diagnosing abdominal aortic aneurysms, a specialized preprocessing Abdominal Aortic Aneurysm Measurement and Evaluation Tool (AMET) was developed. AMET provides visual interfaces with broad measurement capabilities to generate a 3D model of the aorta for a better diagnosis and accurate stent selection. The accuracy and usability of the tool was tested with a …
Training Data Optimization For Anns Using Genetic Algorithms To Enhance Mppt Efficiency Of A Stand-Alone Pv System, Ahmet Afşi̇n Kulaksiz, Ramazan Akkaya
Training Data Optimization For Anns Using Genetic Algorithms To Enhance Mppt Efficiency Of A Stand-Alone Pv System, Ahmet Afşi̇n Kulaksiz, Ramazan Akkaya
Turkish Journal of Electrical Engineering and Computer Sciences
Maximum power point tracking (MPPT) algorithms are used to force photovoltaic (PV) modules to operate at their maximum power points for all environmental conditions. In artificial neural network (ANN)-based algorithms, the maximum power points are acquired by designing ANN models for PV modules. However, the parameters of PV modules are not always provided by the manufacturer and cannot be obtained readily by the user. Experimental measurements implemented in the overall PV system may be used to obtain the ANN dataset. One drawback of this method is that the generalization ability of the neural network usually degrades and some data reducing …
Artificial Bee Colony Algorithm For Dynamic Deployment Of Wireless Sensor Networks, Celal Öztürk, Dervi̇ş Karaboğa, Beyza Görkemli̇
Artificial Bee Colony Algorithm For Dynamic Deployment Of Wireless Sensor Networks, Celal Öztürk, Dervi̇ş Karaboğa, Beyza Görkemli̇
Turkish Journal of Electrical Engineering and Computer Sciences
As the usage and development of wireless sensor networks increases, problems related to these networks are being discovered. Dynamic deployment is one of the main issues that directly affect the performance of wireless sensor networks. In this paper, an artificial bee colony algorithm is applied to the dynamic deployment of mobile sensor networks to gain better performance by trying to increase the coverage area of the network. The good performance of the algorithm shows that it can be utilized in the dynamic deployment of wireless sensor networks.
Automatic Tracking System For Weather Satellite Image Reception, Wassila Leila Rahal, Noureddine Benabadji, Ahmed Hafid Belbachir
Automatic Tracking System For Weather Satellite Image Reception, Wassila Leila Rahal, Noureddine Benabadji, Ahmed Hafid Belbachir
Turkish Journal of Electrical Engineering and Computer Sciences
We present a tracking ground system for low Earth-orbiting (LEO) satellite image reception composed of a software part and a material part. The developed prediction software (LAAR-TRACK) ensures an efficient satellite orbit determination. It is based on the simplified general perturbations model (SGP4) used by the North American Aerospace Defense Command for generating orbital elements. LAAR-TRACK gives the azimuth and the elevation needed for the antenna to signal, in real time, LEO satellites during their passage above the ground receiving station. The software is loaded on a computer directly connected, via the parallel port, to the tracking interface that we …
Trellis-Based Optimization Of Layer Extraction For Rate Adaptation In Real-Time Scalable Stereo Video Coding, Nükhet Özbek
Trellis-Based Optimization Of Layer Extraction For Rate Adaptation In Real-Time Scalable Stereo Video Coding, Nükhet Özbek
Turkish Journal of Electrical Engineering and Computer Sciences
The concept of quality layers (QLs) has been adopted in the scalable video coding standard to enable optimal rate adaptation of precoded video in the rate-distortion sense. QLs were previously extended to stereo and multiple-view scalable video for efficient transport of 3DTV over the Internet. However, it is not possible to use the QL method in applications that require real-time encoding since the priority determination process assumes the availability of the whole video sequence. In this work, a trellis-based online rate adaptation is proposed for real-time scalable stereo video coding, with a delay of 1 group of pictures (GoP). The …
Noncausal Forward/Backward Two-Pass Iir Digital Filters In Real Time, Adnane Mouffak, Belbachir Mohamed Faouzi
Noncausal Forward/Backward Two-Pass Iir Digital Filters In Real Time, Adnane Mouffak, Belbachir Mohamed Faouzi
Turkish Journal of Electrical Engineering and Computer Sciences
A novel method for implementing noncausal forward/backward 2-pass recursive digital filters in real time is presented. It is based on a segment-wise block processing scheme without overlapping. Factors that degrade the linearity of the overall system's transfer function are discussed. An analytical condition that corrects the system's linearity is elaborated upon using the state variable approach. A recursive algorithm is developed to compute an implementable condition for real-time filtering. A single first in, first out queue memory is introduced to ensure an organized and continuous data stream into the proposed system. This technique allows real-time, sample-by-sample filtering, and it yields …
Stability Of The Adaptive Fading Extended Kalman Filter With The Matrix Forgetting Factor, Cenker Bi̇çer, Esi̇n Köksal Babacan, Levent Özbek
Stability Of The Adaptive Fading Extended Kalman Filter With The Matrix Forgetting Factor, Cenker Bi̇çer, Esi̇n Köksal Babacan, Levent Özbek
Turkish Journal of Electrical Engineering and Computer Sciences
The extended Kalman filter is extensively used in nonlinear state estimation problems. As long as the system characteristics are correctly known, the extended Kalman filter gives the best performance. However, when the system information is partially known or incorrect, the extended Kalman filter may diverge or give biased estimates. An extensive number of works has been published to improve the performance of the extended Kalman filter. Many researchers have proposed the introduction of a forgetting factor, both into the Kalman filter and the extended Kalman filter, to improve the performance. However, there are 2 fundamental problems with this approach: the …
Characterization Of A Total Power Radiometer, Murat Celep, Şenel Yaran, Yakup Gülmez, Ari̇f Dolma
Characterization Of A Total Power Radiometer, Murat Celep, Şenel Yaran, Yakup Gülmez, Ari̇f Dolma
Turkish Journal of Electrical Engineering and Computer Sciences
The performance parameters of a total power radiometer designed as a noise measurement system for the frequency range of 12-18 GHz were investigated. The total power radiometer included a low-noise radio frequency section, a narrow-band intermediate frequency section, an average power detector, and a symmetric microwave switch. The radiometer's stability versus time was 0.343 \times 10^{-5} mW/h and its stability against temperature fluctuation was 0.0035 mW/K. The temperature fluctuation of the radiometer was less than 4 mK. We proved that there was no need for active temperature control to obtain stable radiometer gain.