Yazar "Develi, Ibrahim" seçeneğine göre listele

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    Artificial bee colony optimization for modelling of indoor PLC channels: A case study from Turkey
    (ELSEVIER SCIENCE SA, 2015) Develi, Ibrahim; Kabalci, Yasin; Basturk, Alper
    In this study, a channel model which is based on practical channel measurements obtained from electrical networks in Turkey is proposed for power line communication (PLC) systems. Experimental measurements are realized in different cities and various indoor places such as laboratory, university office and apartment house in order to achieve a general and appropriate PLC channel model for different locations and environments. Acquired data from the electric grid are stored on a database and PLC channel modelling process is carried out depending on these data through curve fitting methods. Moreover, parameters of the derived mathematical model are optimized by using artificial bee colony algorithm. Results show that the PLC channel model proposed in this study can be utilized to simulate PLC systems and to perform conformance tests of prototypes. (C) 2015 Elsevier B.V. All rights reserved.
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    Highly reliable LDPC coded data transfer in home networks by using Canete's PLC channel model
    (ELSEVIER SCI LTD, 2014) Develi, Ibrahim; Kabalci, Yasin
    Power line communication (PLC) methods are presently among the most popular technologies for home environments due to their low-cost installation opportunities. In this study, the bit error rate (BER) performance of low-density parity-check (LDPC) coded communication systems is presented by using Canete's PLC channel model over power lines in home networks. Various soft and hard decision LDPC decoders such as belief propagation (BP), weighted bit flipping (WBF), improved weighted bit flipping (IWBF) and implementation-efficient reliability ratio based weighted bit flipping (IRRWBF) decoders are employed in the modeled network. All of the simulations performed in Canete's PLC channel model showed that remarkable performance improvement can be achieved by using short-length LDPC codes. Especially, the improvements are striking when the BP or IRRWBF decoding algorithms are employed on the receiver side. (C) 2014 Elsevier Ltd. All rights reserved.
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    Investigation of S1046 profile bladed vertical axis wind turbine and artificial intelligence-based performance evaluation
    (Taylor & Francis Inc, 2023) Osmanli, Suleyman; Akansu, Selahaddin Orhan; Azginoglu, Nuh; Akansu, Yahya Erkan; Develi, Ibrahim
    It is very important to determine the parameters affecting the performance of the Darrieus-type wind turbine and its effects. In particular, it should be specified at which TSR value the peak power coefficient is obtained. In this study, standard and modified S1046 airfoils and aspect ratios (H/D), angle of attack (AoA), turbulent/non-turbulent flow (WT), number of blades (N), and chord length (C) were tested. Then, four different machines learning-based multi-output regression models (Decision Tree, Linear Regression, K-Nearest Neighbors, and Random Forest) were trained to make performance predictions with the data obtained from the evaluated test setup. Thirdly, feature selection based on the Random Forest algorithm, which is the best performing multi-output regression model, was performed using data due to changing parameter values on the established system. The importance of the parameters was determined. The operating range of the system was at relatively low TSR values. When analyzing the blade profile, the modified blade version performed better in certain combinations compared to the standard profile. Maximum power coefficient (Cp) was obtained from the modified turbine structure with 5 degrees of attack angle, H/D = 1.85, and C = 60 mm. The present study aims to increase the turbine's power coefficient and aims to predict results as power coefficient without doing many different experiments.
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    LDPC coded OFDM systems over broadband indoor power line channels: A performance analysis
    (2013) Kabalci, Yasin; Develi, Ibrahim; Kabalci, Ersan
    Power line communication (PLC) is an emerging technology that aims to provide communication over power lines. In this paper, bit error rate (BER) performances of low-density parity-check (LDPC) coded orthogonal frequency-division multiplexing (OFDM) systems have been investigated in broadband (BB) PLC channels. The performance analyses have been performed for three different indoor channel conditions that were generated by using new and more practical PLC channel model proposal. From the simulation results, it was demonstrated that the LDPC coding scheme offers considerable coding gain with reasonable encoding complexity in the whole channel conditions, when compared to uncoded OFDM systems. © 2013 IEEE.
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    Performance of LDPC coded image transmission over realistic PLC channels for smart grid applications
    (ELSEVIER SCI LTD, 2014) Develi, Ibrahim; Kabalci, Yasin; Basturk, Alper
    Power line communication (PLC) systems are known as the most rapidly enhancing technologies within the smart grid scope due to offering remarkable cost efficiency by decreasing the transmission device requirement. In this study, image transmission performance of low-density parity-check (LDPC) coded communication systems that is based on a realistic PLC channel model is proposed. Very long-term experimental measurements are carried out to acquire the most accurate PLC channel characteristics from a practical grid. A mathematical PLC channel model is derived and the parameters of this model are optimized by using genetic algorithm. The simulation results obtained over the modeled PLC channel have shown that perfect image transmission can be provided by the help of the LDPC coding. The results of this study also emphasize that the proposed system can be employed for image transmission over power lines in the smart grids for security or other purposes. (C) 2014 Elsevier Ltd. All rights reserved.
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    Performance of Two-Hop Relay Assisted Decode-and-Forward Transmission under Mixed Fading Environments
    (KAUNAS UNIV TECHNOLOGY, 2015) Kapucu, Nuri; Bilim, Mehmet; Develi, Ibrahim; Kabalci, Yasin
    This study analyses the performance of two-hop decode-and-forward (DF) relaying protocol under mixed faded channels by evaluating outage probability (P-out) and average bit-error probability (ABEP). It is assumed that the channel between source and relay is Rayleigh fading, whereas the relay-destination link is subject to Weibull fading. First, a closed-form expression is formulated for P-out and then it is used to obtain ABEP for the considered system model. The ABEP performance of two-hop DF relaying is presented for M-ary phase shift keying (M-PSK) signaling with different constellation sizes. Moreover, the proposed analytical expressions are verified by simulations that present the correctness of the derived formulas.