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Öğe A chaos-based image encryption algorithm with simple logical functions(Elsevier Ltd, 2016) Yavuz, Erdem; Yazıcı, Rıfat; Kasapbaşı, Mustafa Cem; Yamaç, EzgiThis paper proposes an effective chaos-based encryption algorithm specialised for images. A system of two independent chaotic functions with high sensitivity to initial states, is utilised to sufficiently apply confusion and diffusion principles for images with any entropy. One of the functions is used for shuffling pixel positions while the other for changing the values of pixels. In the resulting new pixel organisation, adjacent pixels with naturally close values will take on considerably different values, making it difficult to crack the encrypted image. To increase resistance of the system to differential attacks, some logical operations such as exclusive-or and circular rotation are used to spread the effect of a slight change in single pixel intensity of plain image over many pixels in cipher-image. A variety of analyses and tests has been carried out to prove the security and the validity of the algorithm. Even with low entropy images the proposed algorithm has been proved to be more secure and faster than the previous algorithms. © 2015 Elsevier LtdÖğe Design and implementation of a programmable logic controller using PIC18F4580(Institute of Electrical and Electronics Engineers Inc., 2018) Şanver, Ufuk; Yavuz, Erdem; Eyüpoğlu, Can; Uzun, TuncayUse of electricity in industry opened a new age which is dominated by industrial automation. In the beginning, automation systems were based on electro-mechanical systems consisting of relays and contactors. Developments in semiconductor technology inevitably transformed the existing structure and cause electronic-controlled Programmable Logic Controller (PLC) to prevail in the automation systems. PLCs consist of a microcontroller/microprocessor, relay or transistor for switching, isolating equipment such as opto-couplers and voltage converter/inverters. Industrial PLCs are quite expensive devices. In this study, design and implementation of a low-cost PLC using PIC18F4580 microcontroller are realized. Special software including a graphical user-interface is developed for programming the PLC and transferring code data to the device. Both ladder diagram and word instructions can be used for programming the PLC. © 2018 IEEE.Öğe Design and Implementation of a Programmable Logic Controller Using PIC18F4580(IEEE, 2018) Sanver, Ufuk; Yavuz, Erdem; Eyupoglu, Can; Uzun, TuncayUse of electricity in industry opened a new age which is dominated by industrial automation. In the beginning, automation systems were based on electro-mechanical systems consisting of relays and contactors. Developments in semiconductor technology inevitably transformed the existing structure and cause electronic-controlled Programmable Logic Controller (PLC) to prevail in the automation systems. PLCs consist of a microcontroller/microprocessor, relay or transistor for switching, isolating equipment such as opto-couplers and voltage converter/inverters. Industrial PLCs are quite expensive devices. In this study, design and implementation of a low-cost PLC using PIC18F4580 microcontroller are realized. Special software including a graphical user-interface is developed for programming the PLC and transferring code data to the device. Both ladder diagram and word instructions can be used for programming the PLC.Öğe A dynamic neural network model for accelerating preliminary parameterization of 3D triangular mesh surfaces(Springer London, 2019) Yavuz, Erdem; Yazıcı, RıfatThis study proposes an effective and fast preliminary mapping algorithm for 3D triangular mesh surfaces. The proposed method exploits barycentric mapping theory and dynamic neural network for computing parametric coordinates corresponding to vertices of 3D triangular mesh. The dynamic network model iteratively moves internal nodes in 2D parametric space until they convergently reach an equilibrium state. The method effectively computes parametric space coordinates of large meshes (having more than 1.5 K vertices) in less time compared to the traditional method using inverse matrix calculation. The proposed method is tested on many surfaces of varying size, and experimental results prove its efficiency and efficacy. © 2018, The Natural Computing Applications Forum.Öğe E-Commerce Training with Virtual Commerce Simulation(2011) Özpınar, Alper; Yavuz, ErdemOver the last decade, commerce has experienced several major revolutions in size, structure, and competition. The importance of small and medium enterprises (SMEs) has become more important within this market structure. Electronic Commerce, commonly known as electronic marketing or e-commerce that consists of the buying and selling of products or services over electronic systems, is more profitable and affordable than ever before. However, few SMEs have been taking advantage of e-commerce due to the lack of education and training in new technologies. This paper presents the case study of e-commerce training for SME's with the aid of classical classroom training and “Virtual Commerce,” an online commerce game. In Virtual Commerce, every participant owns a company and a certain amount of digital money. They can act as a consumer that purchase from other participant sites and as a supplier for the others. Market conditions, discount rates, and requirements are set by the system operators. This methodology and training has applied to 30 SME's from different sectors. The aim of the project is to lower the costs for the SME's e-commerce training through e-learning and to improve participants’ abilities with online simulation. © 2011, IGI Global. All rights reserved.Öğe An electronic control unit for thermoelectric cooling(Institute of Electrical and Electronics Engineers Inc., 2019) Şanver, Ufuk; Yavuz, Erdem; Eyüpoğlu, CanDue to their efficient operation in small volumes, Thermoelectric Coolers (TECs) have a wide usage in cooling applications, and are preferable wherever usage of compressor-based cooling systems is hard. In this study, a control unit for thermoelectric cooling modules has been designed and implemented based on a microcontroller. The designed system allows users to specify the threshold values for thermoelectric coolers to operate on. The microcontroller drives the TEC using a pulse width modulation (PWM) technique via a MOSFET as a switching component. Adopting a PWM-based control technique makes it possible to manage the speed and energy consumption of the TEC system. © 2019 IEEEÖğe Enhanced chaotic key-based algorithm for low-entropy image encryption(IEEE Computer Society, 2014) Yavuz, Erdem; Yazici, Rifat; Kasapbasi, Mustafa Cem; Yamac, EzgiAs computing power of today's computer enhances rapidly, secure encryption is getting harder and the need for powerful secure encryption methods becomes inevitable. To avoid brute-force attacks it is necessary to have a larger key space, which makes the chaotic systems more attractive. In order to sufficiently apply confusion and diffusion rules for an image data with any entropy structure, a two-dimensional chaotic system, which has high sensitivity to initial states, has been utilized in this study. The fact that adjacent pixels of an image have naturally close values makes it easier for crackers to perform statistical analysis. So, two chaotic functions are used to disrupt correlations among them, one for shuffling pixel positions and one for changing pixels values. Even with low entropy images the proposed algorithm has been proved to be more secure and faster than the previous algorithms. © 2014 IEEE.Öğe Enhanced Chaotic Key-Based Algorithm for Low-Entropy Image Encryption(IEEE, 2014) Yavuz, Erdem; Yazici, Rifat; Kasapbasi, Mustafa Cem; Yamac, EzgiAs computing power of today's computer enhances rapidly, secure encryption is getting harder and the need for powerful secure encryption methods becomes inevitable. To avoid brute-force attacks it is necessary to have a larger key space, which makes the chaotic systems more attractive. In order to sufficiently apply confusion and diffusion rules for an image data with any entropy structure, a two-dimensional chaotic system, which has high sensitivity to initial states, has been utilized in this study. The fact that adjacent pixels of an image have naturally close values makes it easier for crackers to perform statistical analysis. So, two chaotic functions are used to disrupt correlations among them, one for shuffling pixel positions and one for changing pixels values. Even with low entropy images the proposed algorithm has been proved to be more secure and faster than the previous algorithms.Öğe An ensemble of neural networks for breast cancer diagnosis(Institute of Electrical and Electronics Engineers Inc., 2017) Yavuz, Erdem; Eyüpoğlu, Can; Şanver, Ufuk; Yazıcı, RıfatSince breast cancer is a common disease in society all over the world, early diagnosis is of vital importance in order to treat patients before it reaches an irreversible phase. Expert systems are being developed to make it easier to diagnose the disease. In this study, an ensemble of neural networks named radial basis function network (RBFN), generalized regression neural network (GRNN) and feed forward neural network (FFNN) is implemented to separate breast cancer data samples into benign/malignant classes. The utilities of these common methods and the proposed hybrid model which is a combination of these methods are explored and their performances are comparatively presented. The experimental results on Wisconsin Diagnostic Breast Cancer (WDBC) dataset have proven that the proposed method presents a promise for diagnosis of breast cancer. The proposed model can be used as a tool to assist medical specialists in making their decision on the disease. © 2017 IEEE.Öğe An epileptic seizure detection system based on cepstral analysis and generalized regression neural network(PWN-Polish Scientific Publishers, 2018) Yavuz, Erdem; Kasapbaşı, Mustafa Cem; Eyüpoğlu, Can; Yazıcı, RıfatThis study introduces a new and effective epileptic seizure detection system based on cepstral analysis utilizing generalized regression neural network for classifying electroencephalogram (EEG) recordings. The EEG recordings are obtained from an open database which has been widely studied with many different combinations of feature extraction and classification techniques. Cepstral analysis technique is mainly used for speech recognition, seismological problems, mechanical part tests, etc. Utility of cepstral analysis based features in EEG signal classification is explored in the paper. In the proposed study, mel frequency cepstral coefficients (MFCCs) are computed in the feature extraction stage and used in neural network based classification stage. MFCCs are calculated based on a frequency analysis depending on filter bank of approximately critical bandwidths. The experimental results have shown that the proposed method is superior to most of the previous studies using the same dataset in classification accuracy, sensitivity and specificity. This achieved success is the result of applying cepstral analysis technique to extract features. The system is promising to be used in real time seizure detection systems as the neural network adopted in the proposed method is inherently of non-iterative nature. © 2018 Nalecz Institute of Biocybernetics and Biomedical Engineering of the Polish Academy of SciencesÖğe An image processing application to detect faulty bottle packaging(Institute of Electrical and Electronics Engineers Inc., 2017) Şanver, Ufuk; Yavuz, Erdem; Eyüpoğlu, CanUse of automation technologies has received significant attention in recent years and has become one of the crucial parts of industry. The inspection of outputs in a production process is of great importance for companies to produce faultless products. This is vital for companies to sustain credibility and reliability as well. In this study, it is aimed to detect faulty packaging of bottles. Mineral water is bottled in factories and packaged to produce six-bottle and twenty-bottle packs transported on a conveyor belt. Faulty packaged products are rarely observed in this production process. However, it is not acceptable for these faulty products to leave the production line. In this work, an image processing application is implemented to detect and label faulty bottle packages for impeccable production. Sobel filter is utilized for edge detection and Hough transform is used for calculation of number of bottles in packages. The ones labelled as faulty packages are eliminated from conveyor belt by means of a boxer motor. © 2017 IEEE.Öğe An Image Processing Application to Detect Faulty Bottle Packaging(IEEE, 2017) Sanver, Ufuk; Yavuz, Erdem; Eyupoglu, CanUse of automation technologies has received significant attention in recent years and has become one of the crucial parts of industry. The inspection of outputs in a production process is of great importance for companies to produce faultless products. This is vital for companies to sustain credibility and reliability as well. In this study, it is aimed to detect faulty packaging of bottles. Mineral water is bottled in factories and packaged to produce six-bottle and twenty-bottle packs transported on a conveyor belt. Faulty packaged products are rarely observed in this production process. However, it is not acceptable for these faulty products to leave the production line. In this work, an image processing application is implemented to detect and label faulty bottle packages for impeccable production. Sobel filter is utilized for edge detection and Hough transform is used for calculation of number of bottles in packages. The ones labelled as faulty packages are eliminated from conveyor belt by means of a boxer motor.Öğe An implementation of vibration-based automatic score-keeping system for table tennis game(İstanbul Aydın Üniversitesi, 2014) Yavuz, Erdem; Sanver, Ufuk; Kasapbaşı, Mustafa Cem; Yazıcı, RıfatIn sport tournaments human factor plays an important role to evaluate the game. Table tennis is an example of this kind of sports. In order to avoid erroneous human decisions and to enhance referees’ decisions an automatic score-keeping system for table tennis game is designed and implemented with low cost vibration sensors attached underside of the tennis table. The purpose of using vibration sensors is to detect ball colliding with the surface. An additional vibration sensor is also used to detect ball touching the net, determining let state in the game. Petri net scheme is used to model the operation of the system, making it easy to visualize its operation. We believe that the proposed system will contribute much to better evaluate the various phases of table tennis games and to aid the referees to make better decisions.Öğe Improving Initial Flattening of Convex-Shaped Free-Form Mesh Surface Patches Using a Dynamic Virtual Boundary(C R L Publishing LTD, 2019) Yavuz, Erdem; Yazıcı, Rıfat; Kasapbaşı, Mustafa Cem; Bilgin, Turgay TugayThis study proposes an efficient algorithm for improving flattening result of triangular mesh surface patches having a convex shape. The proposed approach, based on barycentric mapping technique, incorporates a dynamic virtual boundary, which considerably improves initial mapping result. The dynamic virtual boundary approach is utilized to reduce the distortions for the triangles near the boundary caused by the nature of convex combination technique. Mapping results of the proposed algorithm and the base technique are compared by area and shape accuracy metrics measured for several sample surfaces. The results prove the success of the proposed approach with respect to the base method.Öğe Karmaşık yüzeylerin düzleştirilmesine yönelik yaklaşım(İstanbul Ticaret Üniversitesi, 2018) Yavuz, Erdem; Yazıcı, Rıfat3B tarama teknolojisinin çok hızlı bir şekilde ilerlemesiyle birlikte serbest biçimli yüzeyler hızla gün yüzüne çıkmakta ve çok sayıda farklı uygulamalarda sayısız endüstriyel ürün tasarımında kullanılmaktadır. Serbest biçimli yüzeyler günümüze ait grafik uygulamalarında önemli bir rol oynamaktadır. Yüzey çizdirme, yüzey kaplama, yüzey örnekleme vb. serbest biçimli yüzeylerle ilgili uygulamaların sonuçları, yüzey parametrelemeye oldukça bağımlıdır. Bu uygulamalarda çoğunlukla parametrelemenin biçim koruyan türden olması ve hızlı bir şekilde yapılması arzulanan bir durumdur. Bu çalışmada geometrik ve mekanik düzleştirme tekniklerini kullanarak konveks biçimli 3B yüzey yamaların düzlemsel karşılıklarının etkili bir biçimde hesaplanmasına yönelik bir yaklaşım geliştirilmiştir. Bu yaklaşımda, 3B yüzey yamasının 2B parametrik düzlem izdüşümüne ilişkin koordinatların hesaplanması için barisentrik izdüşüm teorisine dayanan bir dinamik YSA (Yapay Sinir Ağı) modeli gerçekleştirilmiştir. Bu modelde, barisentrik izdüşüm teorisi yardımıyla yüzey yamasına ilişkin elde edilen yerel geometri bilgisi geri beslemeli dinamik sinir ağına aktarılır. Dinamik sinir ağı modeliyle, izdüşümü yapılacak yüzeye ilişkin noktalar parametrik uzayda denge durumuna ulaşıncaya kadar yinelemeli olarak hareket ettirilir. Geliştirilen yaklaşım, nispeten büyük (nokta sayısı 1.5K'dan daha fazla olan) yüzey yamalarının başlangıç izdüşümüne ilişkin parametrik uzaydaki koordinatlarını, ters matris hesaplamasını kullanan geleneksel yönteme kıyasla etkili bir şekilde daha az sürede hesaplamaktadır. Önerilen yaklaşım, farklı boyutlardaki yüzey yamaları üzerinde test edilerek yöntemin etkinliği ortaya konulmuştur. Geometrik düzleştirme tekniğiyle elde edilen başlangıç izdüşümü mekanik düzleştirme tekniğiyle iyileştirilmiştir. İyileştirme süreci, düzlemde kurulan kütle-yay sistemiyle modellenerek değişken adım büyüklüğüne dayalı bir enerji yayma algoritmasıyla enerji tabanlı olarak gerçekleştirilmiştir.Öğe Modelling and implementation of an automatic table-tennis scoreboarding system(Institute of Electrical and Electronics Engineers Inc., 2016) Şanver, Ufuk; Yavuz, Erdem; Kasapbaşı, Mustafa Cem; Yazıcı, RıfatIncreasing incomes and awards of games leads to better manage games for referees to prevent decision errors. Besides investments made by authorities to better train referees, it is becoming more and more necessary to automatize the game arbitration processes. For amateur games with no referee, there is also a need for an automation system to replace the referee. One of the popular games is table tennis played both at amateur and professional levels. In this study, a table-tennis automatic scoreboarding system is designed and implemented. The designed automation system uses a computer which receives the necessary signals from vibration sensors, makes right decisions according to the rules and controls the peripheral devices such as displays and speakers. This system assists referees to make better decisions in professional games and performs missions of referees in amateur games. © 2016 IEEE.Öğe A novel chaotic image encryption algorithm based on content-sensitive dynamic function switching scheme(Elsevier Ltd, 2019) Yavuz, ErdemThis paper proposes a novel chaotic image encryption algorithm based on a content-sensitive dynamic function switching mechanism. The proposed encryption algorithm is a symmetric cipher, operating on 1D byte sequence. Three independent chaotic maps are utilized for scrambling plain image bytes in order to realize confusion and diffusion properties. The first chaotic map is used for choosing one out of previously encrypted bytes, the second for choosing one out of remaining bytes not encrypted yet, and the last for determining a stochastic value to be externally injected into the stream simply by exclusive-or operation. An innovative content-sensitive dynamic function switching mechanism introducing more random behavior is incorporated in order to ensure high sensitivity to slight changes in plain image bytes. The proposed cryptosystem has gone through various common security analyses and tests to prove its validity. The results demonstrate that the proposed method achieves high security level regarding information entropy, key space, key sensitivity, and resistance to differential, data loss and noise attacks. © 2019 Elsevier LtdÖğe A phoneme-based approach for eliminating out-of-vocabulary problem of Turkish speech recognition using Hidden Markov Model(C R L Publishing LTD, 2018) Yavuz, Erdem; Topuz, VedatSince Turkish is a morphologically productive language, it is almost impossible for a word-based recognition system to be realized to completely model Turkish language. Due to the fact that it is difficult for the system to recognize words not introduced to it in a word-based recognition system, recognition success rate drops considerably caused by out-of-vocabulary words. In this study, a speaker-dependent, phoneme-based word recognition system has been designed and implemented for Turkish Language to overcome the problem. An algorithm for finding phoneme-boundaries has been devised in order to segment the word into its phonemes. After the segmentation of words into phonemes, each phoneme is separated into different sub-groups according to its position and neighboring phonemes in that word. Generated sub-groups are represented by Hidden Markov Model, which is a statistical technique, using Mel-frequency cepstral coefficients as feature vector. Since phoneme-based approach is adopted in this study, it has been successfully achieved that many out of vocabulary words could be recognized.Öğe Real time remote control of robotic hand system - TeleTouch(ICENTE, 2017) Ünal, Musa Sadık; Ertürk, Ersin; Kasapbaşı, Mustafa Cem; Yavuz, Erdem; Şanver, UfukRobots offer an efficient way as assistive devices to perform many errands. In this study, it is aimed to present a proof-of-concept robotic system that is called TeleTouch. s motions/gestures to be transferred in a desired remote location within an acceptable delay. In the implementation, Leap motion sensor, RaspberryPi, and Arduino kits are used. Hand model that is manufactured by 3D printers is actuated by Arduino system which drives the servo motors connected to the hand model. RaspberryPi is used not only for transferring camera view of the hand model to the controlling remote system but also for transferring fingers attributes to the Arduino system. A special software is developed in .Net platform fingers from leap motion sensor. Delay times of the local and remote system are investigated and it is understood that proposed system successfully transfer motion in almost real time.Öğe Recognition of Turkish vowels by probabilistic neural networks using Yule-Walker AR method(2010) Yavuz, Erdem; Topuz, VedatIn this work, recognition of vowels in Turkish Language by probabilistic neural networks is implemented using a spectral analysis method. Power spectral density of the phones obtained from speakers is estimated. Then weighted power spectrum is calculated after power spectral density of that phone is passed through a number of band pass filters. In this way, estimated power spectrums of the phones which are obtained from speakers approximate to a mel scale. Mel scale coefficients obtained, form the feature vector of the phone that is pronounced. These feature vectors constitute the database of the related speaker. Thus and so, every speaker has its own database. When it comes to recognize a phone pronounced by a speaker later, a probabilistic neural network model is created using the database belonging to that speaker. The feature vector of the phone which is to be recognized is computed as mentioned above. In this study, speaker-dependent recognition of Turkish vowels has been realized with an accuracy rate of over 95 percent. © 2010 Springer-Verlag.
