Enhanced Hybrid Method Of Divide-And-Conquer And Rbf Neural Networks For Function Approximation Of Complex Problems,
2017
TÜBİTAK
Enhanced Hybrid Method Of Divide-And-Conquer And Rbf Neural Networks For Function Approximation Of Complex Problems, Mohammed Awad
Turkish Journal of Electrical Engineering and Computer Sciences
This paper provides an enhanced method focused on reducing the computational complexity of function approximation problems by dividing the input data vectors into small groups, which avoids the curse of dimensionality. The computational complexity and memory requirements of the approximated problem are higher when the input data dimensionality increases. A divide-and-conquer algorithm is used to distribute the input data of the complex problem to a divided radial basis function neural network (Div-RBFNN). Under this algorithm, the input data variables are typically distributed to different RBFNNs based on whether the number of the input data dimensions is odd or even. In …
Electronically Tunable Mos-Only Current-Mode High-Order Band-Pass Filters,
2017
TÜBİTAK
Electronically Tunable Mos-Only Current-Mode High-Order Band-Pass Filters, Pipat Prommee, Aphinat Tiamsuphat, Muhammad Taher Abuelmaatti
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents new CMOS current-mode ladder Chebyshev and elliptic band-pass filters (BPFs). The signal flow graph and the network transformation methods are used to synthesize the proposed BPFs by using Chebyshev and elliptic RLC low-pass prototypes. CMOS-based lossy and lossless integrators with grounded capacitors are used to synthesize the proposed BPFs. The proposed filters can be electronically tuned between 10 kHz and 100 MHz by adjusting the bias current from 0.02 $\mu $A to 200 $\mu $A. Both filters use a 1.5 V DC power supply, which leads to low dynamic power consumption. Both filters enjoy total harmonic distortion …
An Inductorless Wideband Lna With A New Noise Canceling Technique,
2017
TÜBİTAK
An Inductorless Wideband Lna With A New Noise Canceling Technique, Pouria Pazhouhesh Moghadam, Adib Abrishamifar
Turkish Journal of Electrical Engineering and Computer Sciences
An inductorless wideband low-noise amplifier (LNA) employing a new noise canceling technique for multistandard applications is presented. The main amplifier has a cascode common gate structure, which provides good input impedance matching and isolation. The proposed noise canceling technique not only improves the noise figure and power gain but also embeds a g$_{m}$-boosting technique in itself, which reduces the power consumption of the main amplifier. Using current-steering and current-reuse techniques in the noise canceling branch makes the design realizable and low power. The proposed LNA is simulated and optimized in 0.13 $\mu $m CMOS technology. The LNA achieves a noise …
Protein Fold Classification With Grow-And-Learn Network,
2017
TÜBİTAK
Protein Fold Classification With Grow-And-Learn Network, Özlem Polat, Zümray Dokur
Turkish Journal of Electrical Engineering and Computer Sciences
Protein fold classification is an important subject in computational biology and a compelling work from the point of machine learning. To deal with such a challenging problem, in this study, we propose a solution method for the classification of protein folds using Grow-and-Learn (GAL) neural network together with one-versus-others (OvO) method. To classify the most common 27 protein folds, 125 dimensional data, constituted by the physicochemical properties of amino acids, are used. The study is conducted on a database including 694 proteins: 311 of these proteins are used for training and 383 of them for testing. Overall, the classification system …
Implementation Of A Flywheel Energy Storage System For Space Applications,
2017
TÜBİTAK
Implementation Of A Flywheel Energy Storage System For Space Applications, Reşat Çeli̇kel, Mehmet Özdemi̇r, Ömür Aydoğmuş
Turkish Journal of Electrical Engineering and Computer Sciences
A satellite power system requires solar panels to provide energy and orientation. There are two regions in the orbital path of the satellite: the dark and bright region. The energy is provided by solar panels in the bright region and by flywheel energy storage system (FESS) in the dark region. Brushless DC (BLDC) motors are widely used in the FESS due to their low weight, high power density, high efficiency, high reliability, and high speed. Some mechanical resonances may occur due to physical features of the mechanical parts. Therefore, the current of the BLDC is dramatically increased because of the …
Maximum Size Of The Pareto Cost Sets For Multi-Constrained Optimal Routing,
2017
TÜBİTAK
Maximum Size Of The Pareto Cost Sets For Multi-Constrained Optimal Routing, Derya Yiltaş Kaplan
Turkish Journal of Electrical Engineering and Computer Sciences
Routing under multiple independent constrains in point-to-point networks has been studied for over 10 years. Its NP-hardness keeps pushing researchers to study approximate algorithms and heuristics, and many results have been published in these years. To the best of our knowledge, the nature of its average case has been explored only for the self-adaptive multiple constraints routing algorithm (SAMCRA), which is an algorithm about multiple constraints routing. In this paper, we simplify SAMCRA into a format that is convenient for our average case analysis. This variant algorithm gives optimal solutions also for very large dimensional networks such as with more …
Electrical Design And Testing Of A 500 Kw Doubly Fed Induction Generator For Wind Power Applications,
2017
TÜBİTAK
Electrical Design And Testing Of A 500 Kw Doubly Fed Induction Generator For Wind Power Applications, Cenk Ulu, Güven Kömürgöz
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, the electrical design and testing of a 500 kW doubly fed induction generator (DFIG) is presented, developed in the context of the MILRES (Turkish National Wind Energy Systems) Project. The main objective of the MILRES Project is to encourage locally produced equipment for wind power systems. Therefore, in the DFIG design, the standard construction capabilities of the local machine manufacturers are especially taken into consideration. In this way, it is aimed that the designed DFIG can easily and cost-effectively be manufactured by local machine manufacturers in Turkey. In the DFIG design procedure, initially, an analytical design of …
An Advanced Robust Fault-Tolerant Tracking Control For A Doubly Fed Induction Generator With Actuator Faults,
2017
TÜBİTAK
An Advanced Robust Fault-Tolerant Tracking Control For A Doubly Fed Induction Generator With Actuator Faults, Samir Abdelmalek, Linda Barazane, Abdelkader Larabi
Turkish Journal of Electrical Engineering and Computer Sciences
Fault-tolerant controller (FTC) designs for doubly fed induction generators (DFIGs) with actuator faults have recently gained considerable attention due to their important role in maintaining the safety and reliability of DFIG-based wind turbines via configured redundancy. The objective of this paper is to propose a novel active fault-tolerant tracking control strategy for a DFIG subject to actuator faults. The proposed strategy consists of first designing a proportional integral observer (PIO) for simultaneous system states and fault estimation and then secondly the FTC, which depends on the estimated states and faults. The objective of such a controller is to drive the …
Rapidly Converging Solution For P-Centers In Nonconvex Regions,
2017
TÜBİTAK
Rapidly Converging Solution For P-Centers In Nonconvex Regions, Monika Mangla, Deepak Garg
Turkish Journal of Electrical Engineering and Computer Sciences
This paper aims to locate $p$ resources in a nonconvex demand plane having $n $demand points. The objective of the location problem is to find the location for these $p$ resources so that the distance from each of $n$ demand points to its nearest resource is minimized, thus simulating a $p$-center problem. We employ various geometrical structures for solving this location problem. The suggested approach is also capable of finding the optimal value of $p$ so that all demand points have at least one resource at a distance $\Delta $, where $\Delta $ is the maximum permissible distance for emergency …
Analysis And Design Of Grid-Connected 3-Phase 3-Level At-Npc Inverter For Low-Voltage Applications,
2017
TÜBİTAK
Analysis And Design Of Grid-Connected 3-Phase 3-Level At-Npc Inverter For Low-Voltage Applications, Emre Avci, Mehmet Uçar
Turkish Journal of Electrical Engineering and Computer Sciences
The 3-level T-type neutral point clamped (T-NPC) inverter has become the most popular multilevel inverter used in low-voltage applications. However, the realization of a bidirectional switch located at the midpoint leg of the T-NPC inverter is achieved using two insulated gate bipolar transistors (IGBTs) with two antiparallel diodes. Power dissipation in these switches is high since there are two semiconductors (an IGBT and a diode) in the current path at the midpoint leg. Switch losses can be reduced and thus the highest conversion efficiency can be achieved if the bidirectional switches in the T-NPC inverter are replaced by highly efficient …
Designing A Vm-Level Vertical Scalability Service In Current Cloud Platforms: A New Hope For Wearable Computers,
2017
TÜBİTAK
Designing A Vm-Level Vertical Scalability Service In Current Cloud Platforms: A New Hope For Wearable Computers, Mustafa Kaiiali
Turkish Journal of Electrical Engineering and Computer Sciences
Public clouds are becoming ripe for enterprise adoption. Many companies, including large enterprises, are increasingly relying on public clouds as a substitute for, or a supplement to, their own computing infrastructures. On the other hand, cloud storage service has attracted over 625 million users. However, apart from the storage service, other cloud services, such as the computing service, have not yet attracted the end users' interest for economic and technical reasons. Cloud service providers offers horizontal scalability to make their services scalable and economical for enterprises while it is still not economical for the individual users to use their computing …
Paper Recommendation Using Citation Proximity In Bibliographic Coupling,
2017
TÜBİTAK
Paper Recommendation Using Citation Proximity In Bibliographic Coupling, Raja Habib, Muhammad Tanvir Afzal
Turkish Journal of Electrical Engineering and Computer Sciences
Research paper recommendation has been a hot research area for the last few decades. Thus far, numerous different paper recommendation approaches have been proposed. Some of these include methods based on metadata, content similarity, collaborative filtering, and citation analysis, among others. Citation analysis methods include bibliographic coupling and co-citation analysis. Much research has been done in the area of co-citation analysis. Researchers have also performed experiments using the proximity of in-text citations in co-citation analysis and have found that it improves the accuracy of paper recommendation. In co-citation analysis, the similarity is discovered based on the frequency of co-cited papers …
An Experimental Study Of Indoor Rss-Based Rf Fingerprinting Localization Using Gsm And Wi-Fi Signals,
2017
TÜBİTAK
An Experimental Study Of Indoor Rss-Based Rf Fingerprinting Localization Using Gsm And Wi-Fi Signals, Gökhan Çeli̇k, Hasari̇ Çelebi̇, Hakan Paşa Partal, Engi̇n Zeydan, İlyas Alper Karatepe, Ahmet Sali̇h Er
Turkish Journal of Electrical Engineering and Computer Sciences
Localization of mobile users in indoor environments has many practical applications in daily life. In this paper, we study the performance of the received signal strength (RSS)-based radio frequency (RF) fingerprinting localization method in a shopping mall environment considering both calibration and practical measurement cases. In the calibration case, the test data for the RSS fingerprinting database are built offline by receiving signals from Global System for Mobile Communications (GSM) base stations, which are collected by a dedicated measurement tool, i.e. the Test Mobile System. In order to see the localization performance, the k-nearest neighbors (K-NN) and random decision forest …
A Parametric Battery State Of Health Estimation Method For Electric Vehicle Applications,
2017
TÜBİTAK
A Parametric Battery State Of Health Estimation Method For Electric Vehicle Applications, Türev Sarikurt, Murat Ceylan, Abdulkadi̇r Balikçi
Turkish Journal of Electrical Engineering and Computer Sciences
Lithium-ion batteries are commonly preferred in electric vehicle applications. The relative capacity and state of health of a battery decrease with age. Therefore, accurate estimation of these parameters is essential. In this study a parametrical approach for estimation of battery state of health is proposed. A hybrid battery model that has a maximum error less than 3% is used. The relative capacity of the battery is estimated by using performance decrement with age. The method is validated by two different set of experiments. The first set is conducted with batteries that were aged by a controlled process and the second …
Two-Group Decodable Distributed Differential Space-Time Code For Wireless Relay Networks Based On Sast Codes,
2017
TÜBİTAK
Two-Group Decodable Distributed Differential Space-Time Code For Wireless Relay Networks Based On Sast Codes, Obada Abdallah, Ammar Abu Hudrouss
Turkish Journal of Electrical Engineering and Computer Sciences
Space-time code can be implemented in wireless relay networks when all relays cooperate to generate the code at the receiver. In this case, it is called distributed space-time code. If the channel response changes very quickly, the idea of differential space-time coding is needed to overcome the difficulty of updating the channel state information at the receiver. As a result, the transmitted signal can be demodulated without any knowledge of the channel state information at the relays or the receiver. In this paper, development of new low decoding complexity distributed differential space-time codes is considered. The developed codes are designed …
An Ultralow Power, 0.003-Mm$^{2}$ Area, Voltage To Frequency-Based Smart Temperature Sensor For -55 $^{\Circ}$C To +125 $^{\Circ}$C With One-Point Calibration, Mudasir Bashir, Sreehari Rao Patri, Krishnaprasad Ksr
Turkish Journal of Electrical Engineering and Computer Sciences
With the scaling of transistor feature size and increased integration density, power density has increased, resulting in high chip temperature, thus degrading the performance and lifetime of the chip. In this work, an ultralow power smart temperature sensor employing a frequency locked loop technique is developed in 65 nm standard CMOS process. The circuit works on the principle of voltage to frequency conversion, exploiting the thermal dependency of threshold voltage (V$_{th})$ of MOS transistors in the subthreshold region. The sensor along with signal conditioning subcircuits has a low power consumption of 1.92 $\mu $W, while operating over -55 $^{\circ}$C to …
Mopso-Based Predictive Control Strategy For Efficient Operation Of Sensorless Vector-Controlled Fuel Cell Electric Vehicle Induction Motor Drives, Adel Abdelaziz Abdelghany Elgammal, Mohammed Fathy El_Naggar
Turkish Journal of Electrical Engineering and Computer Sciences
This paper introduces an optimal control strategy of model-based predictive control (MPC) based on multiobjective particle swarm optimization (MOPSO) for a sensorless vector control induction motor, which is used in a fuel cell electric vehicle drive system. The proposed MPC-MOPSO algorithm is implemented to tune the weighting parameters of the MPC controller to tackle all the conflicting objective functions. The paper handles the following fitness functions: minimizing the speed error, minimizing the torque ripple, minimizing the DC-link voltage ripple, and minimizing machine flux ripple. Computer simulations studies have been completed utilizing MATLAB/Simulink with a specific end goal of assessing the …
Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications,
2017
TÜBİTAK
Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh
Turkish Journal of Electrical Engineering and Computer Sciences
A flexible (2 $\times $ 1) multiple-input, multiple-output (MIMO) antenna with an electromagnetic band gap (EBG) unit cell is designed and measured. The proposed MIMO antenna is based on a circular slotted patch antenna to work at 3.5 GHz. An EBG unit cell is used to reduce the effect of the inherent mutual coupling produced between the closely spaced MIMO elements. The results show that the measured mutual coupling has been reduced by -11.6 dB (from -10 dB to -21.6 dB), and the measured realized gain has been increased by 1.074 dBi (from 1.59 dBi to 2.66 dBi). An improvement …
A New Sequential Power Flow Algorithm For Ac/Dc Systems Including Independent Multiterminal Dc Subsystems,
2017
TÜBİTAK
A New Sequential Power Flow Algorithm For Ac/Dc Systems Including Independent Multiterminal Dc Subsystems, Faruk Yalçin, Uğur Ari̇foğlu
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a new algorithm based on the sequential method for power flow calculation in multiterminal AC/DC systems. The proposed approach differs from other similar studies in the literature by handling two main properties. Firstly, a real equivalent circuit model is considered for the under-load tap changer transformers (ULTCs) of DC converters for the first time in the literature. Hence, new DC equations are obtained. Thus, exact and accurate results can be obtained for practical applications using the proposed algorithm. Tap values adjustment effects of the ULTCs connected to DC converters are included into the Jacobian matrix instead of …
Tsgv: A Table-Like Structure-Based Greedy Method For Materialized View Selection In Data Warehouses,
2017
TÜBİTAK
Tsgv: A Table-Like Structure-Based Greedy Method For Materialized View Selection In Data Warehouses, Mohammad Karim Sohrabi, Hossein Azgomi
Turkish Journal of Electrical Engineering and Computer Sciences
Since a data warehouse deals with huge amounts of data and complex analytical queries, online processing and answering to users' queries in data warehouses can be a serious challenge. Materialized views are used to speed up query processing rather than direct access to the database in on-line analytical processing. Since the large number and high volume of views prevents all of the views from being stored, selection of a proper subset of views to materialization is inevitable. Proposing an appropriate method for selecting the optimal subset of views for materialization plays an essential role in increasing the efficiency of responding …
