Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Karakose, Mehmet(7)
- Yilmazer, Merve(6)
- Boydak, Merve(4)
- Caliskan, Abuzer(4)
- Orhan, Ahmet(4)
- Aslan, Serpil(3)
- Buldu, Gul(3)
- Koseoglu, Murat(3)
- Uyanik, Hakan(3)
- Çil, Zeynel Abidin(3)
- Özceylan, Eren(3)
- Acikkapi, Mehmet Sahin(2)
- Benhala, B.(2)
- Gencer, Cetin(2)
- Gunay, Mihriban(2)
- Hasar, Ugur Cem(2)
- Kaya, Mehmet(2)
- Mete, Süleyman(2)
- Ozkaynak, Fatih(2)
- Qbadou, M.(2)
- Raihani, A.(2)
- Sengur, Abdulkadir(2)
- Ustundag, Aybike(2)
- Varol, A.(2)
- Varol, C.(2)
- Yildirim, Ozal(2)
- Ahmadi, Hadi Badri(1)
- Akkurt, Nevzat(1)
- Akpinar, Muhammed Halil(1)
- Ali, Leila Ait(1)
- Arslan, Samed(1)
- Aslan, Naim(1)
- Atar, Muhammed(1)
- Ay, Betul(1)
- Aydin, Galip(1)
- Aygunes, G.S.(1)
- Barroso, Joaquim J.(1)
- Barroso, Joaquim Jose(1)
- Baykara, Muhammet(1)
- Bürhan, Yücel(1)
Yayınlar
- MakaleAçık Erişim2021Scopus SJRQ1A Method to Determine the Most Suitable Initial Conditions of Chaotic Map in Statistical Randomness Applications
Acikkapi, Mehmet Sahin; Ozkaynak, Fatih
The processes and systems in the real world actually contain order and symmetry. Understanding these order and symmetrical behavior has been a common effort of scientists. Chaos theory has been an interesting topic to understand these order and symmetrical behavior. One of the most important reasons for this interest is the rich dynamics of chaotic systems. A remarkable application of these systems is statistical randomness. Especially in random number generator designs based on discrete time chaotic systems, an important design parameter affecting the success of the generator (statistical randomness properties) is the initial conditions of chaotic maps. Obtaining different initial conditions that will meet the statistical requirements is important in terms of generating different random number sequences. In order to determine the initial conditions, an algorithm that updates the initial conditions depending on the number of successful statistical tests is proposed. Although the proposed design approach is similar to a back propagation neural network, it has a unique design approach. The NIST SP 800-22 test suite has been used to analyze the statistical properties of the proposed generator. It is known that the NIST SP 800-22 test suite is a hypothesis test. Therefore, in order to show the success of the proposed method in the best way, various additional analysis studies have been carried out proving that the generator outputs have a uniform distribution. Using the proposed method, six different initial conditions have been determined that provide statistical random properties for the discrete-time chaotic systems known as logistic map and tent map. 1,000,000 bits have been generated using the obtained initial conditions. These bit values are then converted to decimal values between 0-15. It is observed that the obtained numbers have a uniform distribution. These outputs are thought to be applicable in many areas such as games, simulation, modeling, determination of optimization parameters and cryptology. It is shown in a practical application for cryptographic substitution-box designs to examine the success of the outputs.
AtıfScopus34WoS23OpenAlex29
İncele - BildiriAçık Erişim2021Designing the Clamp System with the Emergency Braking System in the trains by using PLC and SCADA
Ustundag, Aybike; Gencer, Cetin; Paul, R.
As a result of the developments in rail technologies, the vehicles and equipment used in these systems are also developing rapidly. It is in a rapid technological development in vehicles used in rail systems. The resistance forces affecting the movement of the rail system vehicles try to prevent its movement. In addition, the incident adherence and skidding that occur during the course of the rail system vehicles play an important role in the movements of these vehicles. Calculation of forces affecting the movement of rail system vehicles and designing these vehicles accordingly is also important for the safety of these vehicles. When braking is applied on a train running at a certain speed; It stops for a certain time and distance according to road condition, braking and speed on the train. The distance traveled until braking and stopping is the braking distance. Trains have an emergency braking system, but this system locks the train wheels. In this study along with the Anti-Lock Braking System (ABS), the rail clamping system was designed with PLC and SCADA. By using the ABS used in cars on the locomotive and wagons of the train, it is aimed to lock the wheels when the train brakes and to prevent the train from derailment in case of sudden braking with the rail clamp system.
AtıfScopus7OpenAlex7İncele - BildiriAçık Erişim2020Speed Control of DC Motor Using Single Phase Matrix Converter
Boydak, Merve; Orhan, Ahmet; Caliskan, Abuzer
This paper focuses on speed control of DC motor using new driver circuit of Single-Phase Matrix Converter (SPMC). Changing of modulation index has been provided with closed loop PI control. Thus, the voltage applied to the armature has been controlled and rotating of motor at the desired speed has been enabled. Insulated Gate Bipolar Transistors (IGBTs) are used to perform SPMC topology. Sinusoidal Pulse Width Modulation (SPWM) technique is used to obtain switching signals. MATLAB / Simulink is used to implement simulation.
AtıfScopus3WoS3OpenAlex3İncele - BildiriYalnız künye2020Classification of Hand-Drawn Circuit Components by Considering the Analysis of Current Methods
Gunay, Mihriban; Koseoglu, Murat
In this paper, at first, existing classification methods for classifying hand drawn circuits and circuit components are briefly introduced by examining advantages and disadvantages of each classification method. The handled methods are Support Vector Machine method (SVM), nearest neighbor method (KNN) and convolutional neural network method (CNN). Then, in the experimental part of the study, four different hand-drawn circuit components, which are diode, capacitor, resistor and ac voltage source, have been tried to be classified by using CNN method which is a highly recommended classification method in literature. The classification tables and graphics have been presented for the performed study. According to the obtained results and accuracy rate, it is concluded that CNN method can be used reliably to achieve high performance in the classification of hand-drawn circuit components.
AtıfScopus5OpenAlex5İncele - BildiriAçık Erişim2020Using Buck-Boost Rectifier with Single-Phase-Matrix Converter to Reduce Switch Count Operation
Boydak, Merve; Orhan, Ahmet; Caliskan, Abuzer
Recently, the development of advanced power semiconductor devices has made widespread use of power switching circuits and other power electronics applications in commercial and industrial environments. This paper focuses on Single Phase Matrix Converter (SPMC) as a AC-DC boost rectifier and AC-DC buck rectifier. The SPMC was operated in the desired mode using a single driver circuit. Insulated Gate Bipolar Transistors (IGBTs) are used in the power circuit as switching devices to implement SPMC topology. Switching signals are obtained by Sinusoidal Pulse Width Modulation (SPWM) technique. The simulation is carried out using MATLAB / Simulink.
AtıfScopus7WoS3OpenAlex5İncele - BildiriYalnız künye2020Performance Evaluation of Different Window Functions for Audio Fingerprint Based Audio Search Algorithm
Uyanik, Hakan; Koseoglu, Murat
Window functions are structures that are frequently used to increase the quality of the transformation when processing the signal in the time-frequency domain, especially when creating the spectrogram of the signal. In calculations for frequency information, Fourier transforms of short-time samples of the signal are transformed into spectrogram data with the help of window functions, and then operations are performed by using these data. In this study, the performance of three different window functions, which are used in obtaining spectrogram data in the algorithm developed for audio fingerprint-based audio recognition, have been tested under different artificial noise conditions. The results of these three different window functions were compared graphically, and a truth table was obtained based on the analyzed database. As a result of the simulations carried out in MATLAB, it has been observed that the hanning window function gives better spectral results for different noise levels, and accordingly it produces better matching results compared to the other two window functions as reported in former studies on different applications. In addition, some improvements about window length have been added into algorithm to obtain better results.
AtıfScopus12OpenAlex10İncele - BildiriYalnız künye2020Classification of Hand-Drawn Basic Circuit Components Using Convolutional Neural Networks
Gunay, Mihriban; Koseoglu, Murat; Yildirim, Ozal
In this paper, the Convolutional Neural Network (CNN) architecture, which is one of the deep learning architectures, is used to classify the basic circuit components drawn by hand. During the training and testing stages of the model, a new dataset containing images of 863 circuit components manually drawn by different people is created. The data set contains images of four different classes of circuit components such as resistor, inductor, capacitor and voltage source. All images have been fixed to the same size and converted to grayscale to increase recognition performance and reduce process complexity. In the study, training for four classes is performed with CNN architecture. Based on the CNN architecture, four new CNN models are employed with different the number of layers. The training and validation results of these models are compared separately, the model with the highest training and validation performance is observed with four layer CNN model (CNN-4). This model obtained 84.41% accuracy rate at classification task.
AtıfScopus16WoS5OpenAlex17İncele - BildiriAçık Erişim2020Speed Control of DC Motor under Load Condition Using Single Phase Matrix Converter
Boydak, Merve; Orhan, Ahmet; Caliskan, Abuzer
In this study, speed control of a separately excited DC motor was performed using Single Phase Matrix Converter (SPMC). The driver circuit that operates SPMC in buck-boost mode was used. The DC motor was first run without any controller and the change in speed was observed in the case of loading. Then, the motor was run by using PI controller and speed of the motor was kept constant during loading. Switches in the single-phase matrix converter are switched using Sinusoidal Pulse Width Modulation (SPWM) technique. MATLAB/Simulink was used for simulation.
AtıfScopus1İncele - BildiriYayıncıda açık erişim2020Multimode Operation of Single Phase Matrix Converter with Safe Commutation Strategy
Boydak, Merve; Orhan, Ahmet; Caliskan, Abuzer
In this study, the multimode operation of Single-Phase Matrix Converter (SMPC) is examined. The SPMC was operated as a controlled rectifier and frequency converter using a single driver circuit. Mode selection is provided by changing the value of the constant block in the driver circuit. In the rectifier mode, the sinusoidal input voltage was rectified and transferred to the output. Output voltage at the desired frequency value was generated in the frequency changer mode. Voltage peaks in frequency converter mode were prevented with the safe commutation strategy used. Harmonics in the output voltage were examined for different modulation index values. Switches in the SPMC are switched using Sinusoidal Pulse Width Modulation (SPWM) technique. MATLAB/Simulink was used for simulation.
AtıfOpenAlex1İncele - BildiriAçık Erişim2019Predicting Links in Complex Bipartite Networks Based on Strengthening Projections
Aslan, Serpil; Kaya, Mehmet
Link prediction in complex networks is a topic of high interest for many scientists that studied different areas. Many real-world complex networks have naturally bipartite structured. In this work, we proposed a link prediction method for the complex bipartite network. Recently, while link prediction in complex bipartite networks has been extensively studied, there isn't still sufficiently suitable methods for this networks. The previous works usually have some limitations. They first map the bipartite network into the unimodal projection networks. Then, they perform the link prediction using only the properties of the projection networks. However, these projection networks involve many node pairs with weak relationships when used in networks constructed from real-world data. These weak relationships lead to low probability predictions and high computation time for the algorithm. In this paper, to overcome these limitations, we first map the bipartite network into strengthening projection network model that consists of nodes that have only strong relationships. Based on this projection network, we presented the link prediction method for the complex bipartite network. We conducted extensive experiments on complex bipartite networks. The results of the experiments demonstrate that our proposed method can effectively solve the link prediction problem in complex bipartite networks.
AtıfScopus2OpenAlex2İncele - BildiriAçık Erişim2019Predicting Collaboration Relationships on Social Network
Aslan, Serpil; Kaya, Buket; Varol, A.; Yazici, A.; Yazici, M.A.; Varol, C.; Aygunes, G.S.; Cotur, A.
Scientific papers are mostly performed by collaboration between research groups. Researchers work in various subjects and in several research areas. Therefore, identifying a strong research group is a quite complex task. To cope with this complex task, we propose a network-based method that predicts the best appropriate collaborations for researchers in a co-authorship network. In this paper, we have constructed a weighted co-authorship network by using a real database of scientific papers. Almost all of the methods in this area use the unweighted network model. But, weighted networks are particularly important when representing the network-based properties. The constructed network consists of nodes and links which represent respectively authors and their collaborations. In these networks, if two researchers are the common authors in the same paper, they are considered connected. Typically, the link weights represent the number of papers that two authors have made collaboratively. We also use local LCP-based algorithms to calculate the betweenness and closeness of the authors in this paper. The experimental results demonstrate the success of the proposed method.
AtıfScopus3OpenAlex2İncele - BildiriAçık Erişim2019Bigailab-4race-50K: Race Classification with a New Benchmark Dataset
Talo, Muhammed; Ay, Betul; Makinist, Semiha; Aydin, Galip
Face analysis is the process of extracting useful information such as gender, age and race from a face image. In this study, we look at ways of closing the gap between the capabilities of automatic facial recognition and race classification methods. For this purpose, we take the following two steps. (1) We offer a public race dataset consisting of labeled images to overcome the challenges of real-world race estimation tasks. (2) We present a benchmark study to find race of a human face using a pre-trained Convolutional Neural Network (CNN) model on the large-scale face dataset. We are able to achieve a remarkable accuracy of 97.6% in race classification task.
AtıfScopus3OpenAlex5İncele - BildiriAçık Erişim2019A Hybrid recommendation system in co-Authorship networks
Aslan, Serpil; Kaya, Mehmet
Recommender systems are an important field that aim to direct users more quickly to their needs. Scientific research studies in academic field are mostly carried out by collaboration between scientists. Finding new collaborations and analyzing the quality of them are quite complicated situations. Therefore, developing a system that recommend strong collaborations for scientists can be an invaluable tool. In this study, we present a hybrid recommendation method that uses both collaborative filtering and a network-based method by examining the structure of the co-Authorship network that was created by using a real database of scientific articles in computer science. In the constructed network, the nodes represent scientists and links represent the coauthorship relationships. If two scientists in the network have been co-Author of at least one article, they are considered to be connected. Many of the present recommendation methods in this area take into account only the common neighbors of the nodes, while calculating the similarity of the node pairs in the network. To overcome these limited methods, we use the local community-based similarity indexes which also take into account the similarities between the common neighbors of the nodes. When the experimental results are examined, they prove the success of the proposed method.
AtıfScopus7WoS3OpenAlex6İncele - MakaleAçık Erişim2019Scopus SJRQ1Side-Channel Analysis of Chaos-Based Substitution Box Structures
Acikkapi, Mehmet Sahin; Ozkaynak, Fatih; Ozer, Ahmet Bedri
There is a theoretically strong relationship between chaos and cryptology. In practice, one of the most successful applications of this relationship is chaos-based s-box structures. However, the performance metrics of chaos-based s-box designs are worse compared to those for s-box structure based on algebraic techniques used in modern encryption algorithms, such as the AES algorithm. What is the reason for using chaos-based s-box structures, even though they have worse cryptographic characteristics? Researchers claim that they may be an alternative defense against implementation attacks, especially side-channel analyses. However, no studies have supported or refuted this claim so far. In this paper, side-channel analyses have been performed for two different chaos-based s-box structures. These two s-box structures have been selected for having with the best and worst performance measurements for s-box structures previously proposed in the literature. The results were compared with the AES s-box structure. Analysis of the results showed that chaos-based s-box structures are more resistant against side-channel attacks. Therefore, chaos-based designs may be an alternative defense against implementation attacks, as alleged. However, both algebraic and chaos-based s-box designs have been observed to be insecure if the attacker has more than 30 plaintexts in the side channel analyses. These results show that implementation analysis studies are required in the chaos-based cryptology literature.
AtıfScopus48WoS42OpenAlex51İncele - BildiriYalnız künye2018Quality lignite coal detection with discrete wavelet transform, discrete fourier transform, and ANN based on k-means clustering method
Korkmaz, Sevcan Aytac; Esmeray, Furkan; Varol, A.; Karabatak, M.; Varol, C.
In this article, the lignite coal datas in the Kalburcayi area of the Sivas-Kangal Basin have been used. This original data obtained from Kalburcayi area of the Sivas-Kangal Basin consists of 66 observations in the lignite coal area, including lignite quality parameters such as moisture content, ash, sulfur content and calorific value. These lignite coal datas have been clustered in two group with k-means method according to calori values. This clustering lignite coal data is classified by the Artifical Neural Network (ANN) classifier. In addition, Discrete Fourier Transform (DFT) and Discrete Wavelet Transform (DWT) have been applied to coal data for ANN classifiers. DFT-ANN, DWT-ANN, and ANN classification success results are compared. The highest classification success rate was found by DWT-ANN method.
AtıfScopus8OpenAlex12İncele - MakaleAçık Erişim2018Scopus SJRQ1Determination of effective constitutive parameters of inhomogeneous metamaterials with bianisotropy
Hasar, Ugur Cem; Buldu, Gul; Kaya, Yunus; Ozturk, Gokhan
A recursive algorithm is proposed to accurately extract the electromagnetic parameters of isotropic/bianisotropic metamaterial (MM) slabs of inhomogeneous structures. The algorithm is based on the recursive calculations of measured/ simulated forward and backward scattering (S-) parameters from previously extracted wave impedances and refractive indices of each homogeneous layer (except the analyzed intermediate layer) by a suitable retrieval method. There are two main advantages of our proposed method over existing extraction algorithms. First, it could retrieve the electromagnetic parameters of both isotropic and bianisotropic MM slabs. Second, it is applicable for electromagnetic parameter extraction of inhomogeneous structures. For validation of our method and assessing its accuracy over existing extraction methods, we used the simulation results of various inhomogeneous structures constructed by different isotropic/bianisotropic MM slabs (split-ring-resonator (SRR), SRR-wire, omega, and omega-wire). For completeness, the effects of noise present in S-parameters and iterative error (by increasing the value of iteration numbers) are examined to test the robustness of the proposed algorithm.
AtıfScopus43WoS42OpenAlex47İncele - BildiriYalnız künye2017An efficient heuristic algorithm for solving robotic assembly line balancing problem
Çil, Zeynel Abidin; Mete, Süleyman; Özceylan, Eren
In the assembly system, robots provide to increase flexibility of the system and automation. The balancing robotic assembly line (RALB) problem consists two main works, which are not only assigning task to station, but also allocation robots in stations. Because each robots can perform different performance on the same tasks due to their capabilities. In this study, iterative beam search algorithm is developed to minimize cycle time. The performance of the algorithm outperforms other algorithm in the literature.
AtıfScopus2OpenAlex1İncele - MakaleYalnız künye2017Scopus SJRQ1Waveguide Method for Electromagnetic Parameter Extraction of Weakly Coupled Metamaterials
Hasar, Ugur C.; Buldu, Gul; Barroso, Joaquim J.
A retrieval method is proposed for electromagnetic parameter extraction of metamaterial (MM) slabs having electric coupling to magnetic resonance (weak coupling) from waveguide measurements. Underlying expressions of electromagnetic properties in the retrieval process are derived. The method is validated by the simulated and measured waveguide scattering parameters of an MM slab constructed by split-ring-resonators.
AtıfScopus13WoS13OpenAlex15İncele - BildiriYalnız künye2017A heuristic approach for joint design of assembly and disassembly line balancing problem
Mete, Suleyman; Çil, Zeynel Abidin; Özceylan, Eren
Balancing assembly and disassembly on parallel line together will positively affect to remanufacture production systems. In this study, two lines, which is one for assembly and other for disassembly, are considered as parallel line configuration. Parallelization of lines helps decrease the need for workforce significantly. Therefore, we propose heuristic approach based on ant colony optimization (ACO) for solving the balancing parallel line with minimizing number of workstations.
AtıfScopus2OpenAlex3İncele - BildiriAçık Erişim2017Face recognition based on convolutional neural network
Coskun, Musab; Ucar, Aysegul; Yildirim, Ozal; Demir, Yakup
Face recognition is of great importance to real world applications such as video surveillance, human machine interaction and security systems. As compared to traditional machine learning approaches, deep learning based methods have shown better performances in terms of accuracy and speed of processing in image recognition. This paper proposes a modified Convolutional Neural Network (CNN) architecture by adding two normalization operations to two of the layers. The normalization operation which is batch normalization provided acceleration of the network. CNN architecture was employed to extract distinctive face features and Softmax classifier was used to classify faces in the fully connected layer of CNN. In the experiment part, Georgia Tech Database showed that the proposed approach has improved the face recognition performance with better recognition results.
AtıfScopus250OpenAlex295İncele