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Öğe AIR CONTAMINATION MEASUREMENT AND VISUALIZIATION APPLICATION WITH WIRELESS SENSOR NETWORKS(Ieee, 2014) Şentürk, Arafat; Kara, ResulThe reasons of using Wireless Sensor Networks (WSN) technology are being more suitable to natural conditions than the cabled one, its reliability, its flexible structure, producing a solution with low cost, self organization, using its energy balanced inside the network and providing easy establishment. The purpose of wireless sensor networks is to provide easy access to signal at any moment. It performs this by collecting data, processing, analyzing and disseminating it. In this study, air contamination measurement and visualization system with WSN is developed and applied. Sensors which are programmed to quantify the density of Methane (CH4), carbon monoxide (CO), isobutene (C4H10), ethanol (CH3CH2OH) and hydrogen (H-2) gases are placed into the planned regions in Duzce University Konuralp Campus and the density of each gas in every region has been taken. Air contamination is determined by these gas density values. Data taken by sensors has been transferred to MySql database, and then it is transferred to the visualization interface that is prepared by PHP web programming language. Air contamination changes are shown instantly on a map given in the web interface.Öğe Analysis of fuzzy logic usage in PBHRA routing algorithm in wireless ad hoc networks(2010) Kara, Resul; Özçelik, İbrahim; Ekiz, HüseyinMobile ad hoc networks are composed of nodes communicating with each other without any infrastructure. Position based routing algorithms used in these networks makes the decision of routing by considering the location information of wireless nodes. In this study, the effect of using fuzzy logic during the decision making about routing of nodes that are using one of the location information based algorithm PBHRA (Position Based Hybrid Routing Algorithm) in the literature has been examined. 50-noded and 100-noded networks that are using PBHRA have been subjected to routing operation with and without using fuzzy logic. The results have been given relatively. It is shown that the usage of fuzzy logic provides the effective usage of band width and battery life, which are counted as the constraints of ad hoc networks. © 2010 IEEE.Öğe AN ANALYSIS OF IMAGE COMPRESSION TECHNIQUES IN WIRELESS MULTIMEDIA SENSOR NETWORKS(Univ Osijek, Tech Fac, 2016) Şentürk, Arafat; Kara, ResulWireless Multimedia Sensor Networks (WMSNs) provide realization of applications which are usable everywhere and address many fields like mobile health care, environmental surveillance and traffic monitoring. Large amount of data causes to traffic in memory resources, difficulties in operation, and excessive power consumption - which is the most important one - for every node while WMSNs transfer multimedia data during those applications. Those kinds of problems are vital for WMSNs which already have limited resources. Image compression can be one of the effective solutions to overcome those problems. Thus, network lifetime of WMSNs can be increased significantly and the bandwidth can be used in a more effective way. The main purpose of this study is to investigate image compression algorithms used for WMSNs in the literature and to show which algorithm is advantageous in which case by making comparisons among them.Öğe Binary apple tree: A game approach to tree traversal algorithms(2012) Şentürk, Zehra Karapınar; Şentürk, Arafat; Zavrak, Sultan; Kara, Resul; Erdoğmuş, PakizeThe computer science students mostly face with the difficulties in learning the topics of algorithms courses. Only listening the topic from the teacher or just writing makes the learning volatile. Instead of listening or writing, if there is something visual, it would be more permanent to learn because visuality increases the learning potential and the time for learning is minimized. The adversities of classical education techniques were intended to be eliminated in this study via computer games which are becoming more and more popular in this age. An educational convenience is provided for the subject of tree traversal algorithms. Tree traversal algorithms are one of the basic and confused concepts in algorithms and programming courses in computer science. A game called "binary apple tree" was established to teach and learn the subject easier. © 2012 IEEE.Öğe Comparison of Image Compression Algorithms Used in Wireless Multimedia Sensor Networks(Ieee, 2016) Şentürk, Arafat; Kara, ResulWireless Multimedia Sensor Networks (WMSN) are used to transfer large amount of data like audio, image, and video. The multimedia data which is gathered from the environment is processed and then transferred to another sensor or a sink in WMSN. Except for the special applications, in WMSN, there is only compression operation on the data. In this study, image compression and decompression times of three image compression algorithms: Discrete Cosine Transform -DCT, Set Partitioning in Hierarchical Trees - SPIHT, Low Energy Image Compression Algorithm - LEICA, which are also frequently used for WMSN are compared. The algorithms are first encoded by C programming language and run on a virtual machine with Windows OS, which owns hardware requirements of the sensors. Then, the obtained data is evaluated in terms of compression and decompression times.Öğe Comparison of Real Time Image Transfer in Wireless Multimedia Sensor Networks(Ieee, 2015) Şentürk, Arafat; Şentürk, Zehra Karapınar; Kara, ResulWireless Multimedia Sensor Networks (WMSN) allows developing many applications which addresses to many areas like mobile healthcare, environmental monitoring and traffic monitoring. During those applications, real time data transmission is very important in terms system security and usability while the multimedia data is processed and transferred. Namely, it is required to transfer data taken from a sensor to another sensor or to a base station as soon as possible. The most time-consuming part is caused by image compression algorithms. In this study, the computation speeds of the basic image compression algorithms Discrete Cosine Transform (DCT) and Embedded Zero-tree Wavelet (EZW) are compared. This operation is realized on the sensors and the transmission time is not added to the computation time. The algorithms are compared via MATLAB. This study may set light to the efficiencies of some algorithms which are derived from the compared algorithms in real time image transmission.Öğe A Comparison on Broadcast Encryption Schemes: A New Broadcast Encryption Scheme(Univ Suceava, Fac Electrical Eng, 2020) Bodur, Huseyin; Kara, ResulIn broadcast communication, the schemes in which encryption methods are employed are often used to transmit messages from a source to multiple users. There arc three types of scheme categories: central, contributory and hybrid schemes. In this work, three central techniques which are widely used nowadays are discussed: Logical Key Hierarchy (LKH), One-way Function Tree (OFT) and One-way Function Chain (OFC). A new central broadcast scheme has also been proposed. This scheme uses an asymmetric encryption method in the root node and the user nodes and, as opposed to other central schemes, a symmetric encryption method as well. It contains a hash() function in the intermediate node calculations. The proposed scheme was compared with the existing schemes in terms of number of key transmissions, number of operations, number of user keys, size of user keys, and size of key transmission in user adding/removing and batch user adding/removing operations. The results are shown graphically.Öğe ddosdaps4web: Web'e Yönelik DDoS Tespit ve Koruma Yöntemi(2016) Kabakuş, Abdullah Talha; Kara, ResulHer koruma tespitle başlar. Dağıtık servis engelleme (DDoS) saldırıları, ağları veya bilgisayarlara yoğunkullanım sonucunda verdikleri servisi engellenmektedirler. Günümüzde bilgisayarlardaki yazılımsal vedonanımsal gelişmelere rağmen, kısa bir zaman dilimi DDoS ataklarının kötücül etkilerini gerçekleştirmesiiçin yeterli olmaktadır. Bu sebepten ötürü DDos saldırılarını engellemek için gerçek zamanlı bir tespit vekoruma sistemine ihtiyaç duyulmaktadır. Geleneksel ağ tabanlı koruma sistemleri uygulama katmanı DDoSataklarına karşı güvenlik sağlayamamaktadır. Bu çalışmada, HTTP tabanlı DDoS ataklarını tespit etmek vesistemi korumak için ddosdaps4web isimli DDoS tespit ve koruma sistemi öne sürülmüştür. ddosdaps4webüç servisten faydalanmaktadır: (1) Tüm HTTP isteklerinin depolanıp, istek başlıklarından detaylı analiz içinbilgi çıkartımı yapılmasını sağlayan depolama servisi, (2) her dakika çalışan ve ön tanımlı istek limitlerinegöre kötücül istekleri tespit etmeyi sağlayan izleme servisi, ve (3) gelen bütün istekleri keserek, oluşturulankurallara göre kötücül olanları devre dışı bırakan durdurucu servisi. ddosdaps4web rastgele oluşturulmuş10000 HTTP isteği üzerinden test edilerek DDoS doğru tespit oranı %94 olarak bulunmuştur.Öğe Diagnosis of paroxysmal atrial fibrillation from thirty-minute heart rate variability data using convolutional neural networks(Tubitak Scientific & Technical Research Council Turkey, 2021) Surucu, Murat; Isler, Yalcin; Kara, ResulParoxysmal atrial fibrillation (PAF) is the initial stage of atrial fibrillation, one of the most common arrhythmia types. PAF worsens with time and affects the patient's life quality negatively. In this study, we aimed to diagnose PAF early, so patients can start taking precautions before this disease gets worse. We used the atrial fibrillation prediction database, an open data from Physionet and constructed our approach using convolutional neural networks. Heart rate variability (HRV) features are calculated from time-domain measures, frequency-domain measures using power spectral density estimations (fast Fourier transform, Lomb-Scargle, and Welch periodogram), time-frequency-domain measures using wavelet transform, and nonlinear Poincare plot measures. We also normalized these features using min-max normalization and z-score normalization methods. In addition, we also applied alternatively the heart rate normalization (HRN), which gave promising results in a few HRV-based research, before calculating these features. Thus, HRV data, HRN data, and HRV features extracted from six different combinations of these normalizations, in addition to no normalization cases, were applied to the convolutional neural networks classifier. We tuned the classifiers using 90% of samples and tested the classifiers' performances using 10% of data. The proposed approach resulted in 95.92% accuracy, 100% precision, 91.84% recall, and 95.74% f1-score in HRV with z-score feature normalization. When the heart rate normalization was also applied, the proposed approach reached 100% accuracy, 100% precision, 100% recall, and 100% f1-score in HRV with z-score feature normalization. The proposed method with heart rate normalization and z-score normalization methods resulted in better classification performance than similar studies in the literature. In addition, although deep learning models offer no use of separate feature extraction processes, this study reveals that using HRV-specific feature extraction techniques may improve the performance of deep learning algorithms in HRV-based studies. Comparing the existing studies, we concluded that our approach provides a much better tool to diagnose PAF patients.Öğe Distance network learning with real network devices(2010) Kara, Resul; Şentürk, Zehra Karapınar; Erdoğmuş, PakizeNetwork education given in the universities and in the other education areas constitutes the backbone of computer science. This education is provided not only in theoretical form but also in the practical way. Since it is hard to settle some information of computer networks in learners' mind practices are the necessary activities of learning process. As the visuality increases, learners start learning easier. So, network education is given in the applied form with real devices such as switches, routers, servers, etc. Although it is necessary to perform this education in this way, it may not always be possible with some reasons like high cost and installation hardness. The reason of planning to do this project comes exactly from this point. We are supposed to get over the difficulties of a qualified network education with some techniques used for distance learning and the remote communication with the network devices. To realize the project we will use the network labs of computer engineering department of Düzce University. With only this lab we will reach many learners and this will be profitable for both the client and the manufacturer. The system will include authorization, network knowledge assessment test, application, and logging out operations. After opening the system some questions are directed to the users optionally and according to the result of the assessment related part of the lesson is given. In this point, users first interact with the authorization server and then they are directed to the application server. Next, they will be using the network devices out of classroom wherever they want. ©2010 IEEE.Öğe FATIGUE LIFE PREDICTIONS OF METAL MATRIX COMPOSITES USING ARTIFICIAL NEURAL NETWORKS(Polska Akad Nauk, Polish Acad Sciences, Inst Metall & Mater Sci Pas, 2014) Uygur, İlyas; Çiçek, Adem; Toklu, Ethem; Kara, Resul; Sarıdemir, SuatIn this study, fatigue life predictions for the various metal matrix composites, R ratios, notch geometries, and different temperatures have been performed by using artificial neural networks (ANN) approach. Input parameters of the model comprise various materials (M), such as particle size and volume fraction of reinforcement, stress concentration factor (Kt), R ratio (R), peak stress (S), temperatures (T), whereas, output of the ANN model consist of number of failure cycles. ANN controller was trained with Levenberg-Marquardt (LM) learning algorithm. The tested actual data and predicted data were simulated by a computer program developed on MATLAB platform. It is shown that the model provides intimate fatigue life estimations compared with actual tested data.Öğe Fuzzy Logic and Image Compression Based Energy Efficient Application Layer Algorithm for Wireless Multimedia Sensor Networks(Comsis Consortium, 2020) Senturk, Arafat; Kara, Resul; Ozcelik, IbrahimWireless Sensor Networks (WSN) are the networks that can realize data processing and computation skills of sensor nodes over the wireless channel and they have several communication devices. Wireless Multimedia Sensor Networks (WMSN) are the networks composed of low-cost sensor nodes that transmit real-time multimedia data like voice, image, and video to each other and to sink. WMSN needs more energy and bandwidth than WSN since they transmit a larger amount of data. The size of the data transmitted by the sensor nodes to each other or the sink becomes an important factor in their energy consumption. Energy consumption is a fundamental issue for WMSN. Other issues that affect the progress of WMSN are limited bandwidth and memory constraints. In these networks, for which the node battery lives are important sources, the limited sources must be effectively used by decreasing the transmitted data amount by removing the redundant data after proper processing of the environmental data. A new algorithm is developed to minimize the energy consumption during image data transmission between sensor nodes on WMSN, and so, make the nodes use their most important source, battery life ef-fectively in this study. This algorithm is named as Energy-aware Application Layer Algorithm based on Image Compression (EALAIC). This algorithm makes use of the top three image compression algorithms for WMSN and decides instantly to which one is the most efficient based on three parameters: the distance between the nodes, total node number, and data transmission frequency. In this way, the sensor node battery lives are used efficiently. The performance analysis of the developed algorithm is also done via Network Simulator - 2 (NS - 2) and it is compared by the existing algorithms in terms of energy rate (consumed energy/total energy) and PSNR (Peak Signal to Noise Ratio).Öğe A game to test pointers: Path finding(2012) Şentürk, Zehra Karapınar; Zavrak, Sultan; Şentürk, Arafat; Kara, Resul; Erdoğmuş, PakizePointers are one of the most difficult to understand topics in programming courses. Since the topic is some virtual, the students of computer science face with difficulties in understanding. They hardly imagine the addresses of memory cells, their contents, and the pointers pointing to those memory cells. To test the knowledge and to reinforce the explanations done on the lecture hours, we have intended to create a game related to pointers. This game was constituted with the purpose of visualizing the concept of pointers into the students' brains and so to increase the understanding of the subject. The students will not only listen the topic from the teacher or just write, but in an evaluation test, they will also see what is going on in the memory cells of their computer. This will make the teaching more and more permanent. © 2012 IEEE.Öğe GRAPH-BASED SENTENCE LEVEL SPELL CHECKING FRAMEWORK(Inst Integrative Omics & Applied Biotechnology, 2017) Kabakuş, Abdullah Talha; Kara, ResulSpelling mistakes are very common on the web, especially when it comes to social media, it is much more common since (1) users tend to use an informal language that contains slang, and (2) the character limit defined by some social services such as Twitter. Traditional string similarity measurements (1) do not consider the context of the misspelled word while providing alternatives, and (2) do not provide a certain way to choose the right word when there are multiple alternatives that have the same similarity with the misspelled word. Therefore, we propose a novel sentence level spell checking framework that targets to find "the most frequently used similar alternative word". 146,808 sentences from different corpora are stored in a graph database. The similarity is calculated by using Levenshtein distance algorithm alongside the similarity between two given words. As the experimental results are presented in the discussion, the proposed framework is able to correct misspellings which cannot be corrected by traditional string similarity measurement based approaches. The accuracy of the proposed framework is calculated as 84%. Since the proposed framework uses a slang dictionary to determine misspelled words, it can be used to correct misspellings in the social media platforms.Öğe HASTANE PNÖMATİK SİSTEMLERİNİN BULANIK MANTIKLA MODELLENMESİ(2020) Özgür, Büşra; Kara, ResulOtomasyon, robotik ve hastaneler gibi oldukça geniş kullanım alanı olan; Pnömatik sistemlerle ilgili hassas kontrol uygulamalarına yönelik çalışmalar giderek artmaktadır. Ancak sistemin lineer olmayan ve karmaşık bir yapıya sahip olması, sistemin kontrol edilmesini zorlaştırmaktadır. Sistemin davranışını belirlemek ve verilen girişlere göre çıkışların ifade edilmesi için matematiksel modeller kullanılmaktadır. Amaç sistemin davranışının öngörülmesi ve kontrolüdür. Doğrusal sistemler için birçok kontrol teorisi varken, doğrusal olmayan sistemlerde kontrol teorileri kısıtlıdır. Doğrusal olarak modellenemeyen sistemler bulanık olarak modellenebilir. Böylece lineer olmayan sistemlerin kontrolleri daha kolay bir şekilde sağlanmaktadır. Hastanelerde kullanılan pnömatik sistemler sayesinde numune alınan odalar ile laboratuvar arasında zaman ve enerji açısından büyük bir tasarruf sağlar. Hastane pnömatik sistemleri de lineer olmayan bir yapıya sahiptir ve bulanık mantıkla modellenerek sistemin en verimli şekilde kontrolü amaçlanmaktadır. Bu sayede hastane pnömatik sistemleri, daha etkili bir şekilde kullanılabilecek, karşılaşılan problemlere daha kolay bir şekilde çözüm bulunabilecek ve sistem verimliliği en üst seviyeye ulaşabilecektir. 4 giriş ve 1 çıkış parametresi kullanılarak bulanık mantıkla modellenen sistemin başarısı yaklaşık olarak %90 (%91,6) dır.Öğe Image Compression Techniques in Wireless Multimedia Sensor Networks(Ieee, 2015) Şentürk, Arafat; Şentürk, Zehra Karapınar; Kara, ResulWireless Multimedia Sensor Networks (WMSNs) provide realization of applications which is usable everywhere and address to many fields like mobile health care, environmental surveillance and traffic monitoring. Amount of data causes to traffic in memory resources, difficulties in operation, and excessive power consumption which is the most important one-for every node while WMSNs transfer multimedia data during those applications. That kind of problems is vital for WMSNs which already have limited resources. Image compression can be one of the effective solutions to overcome those problems. Thus, network lifetime of WMSNs can be increased significantly and the bandwidth can be used in a more effective manner. The main purpose of this study is to investigate image compression algorithms used for WMSNs in the literature in terms of their advantages and disadvantages after giving brief information about WMSNs.Öğe IMPLEMENTATION OF E-LEARNING CIRCUIT ANALYSIS SOFTWARE FOR SIMPLE DIRECT CURRENT ELECTRICAL CIRCUITS(Iated-Int Assoc Technology Education A& Development, 2013) Zavrak, Sultan; Pehlivan, Hüseyin; Kara, ResulElectric circuits form the principal subject of many undergraduate courses in electrical and electronic engineering. For most higher education students, it is a difficult process to learn the analysis and solution of such circuits. In this study, we present the description of an education program that can analyze simple direct current (DC) electrical circuits and generate instructive documents with all their intermediate solution steps. The circuits currently comprise resistors, independent current and voltage sources only. Besides, the program is equipped with some useful features such as the calculation of equivalent resistance, the construction and solution of Thevenin equivalent circuits and the automatic generation of electrical circuits.Öğe Implementing Diffie-Hellman Key Exchange Method on Logical Key Hierarchy for Secure Broadcast Transmission(Ieee, 2017) Bodur, Hüseyin; Kara, ResulWith the rapid growth of the internet, broadcast communication has become an important issue for many different areas and applications. The broadcast communication allows a source to send messages to all or certain group of the users connected to the source. Secure encryption algorithms are often used to ensure that message transmission is secure Today's encryption algorithms, regarded as reliable, include Diffie-Hellman key exchange. In this study, the creation of a common secret key value from the root node to the user is considered and compared with other methods by applying Diffie-Hellman key exchange on Logical Key Hierarchy (LKH) which is a broadcast communication scheme.Öğe Öğe Kablosuz Multimedya Algılayıcı Ağlarda Enerji Verimliliği için Katmanlı Mimari Üzerinde Bir Araştırma(2017) Şentürk, Arafat; Kara, ResulKablosuz Multimedya Algılayıcı Ağ (KMAA)'lar için enerji tüketimi en önemli problemdir. KMAA'lar Kablosuz Algılayıcı Ağ (KAA)'lara göre daha büyük boyutta veri aktardıkları ve veriler üzerinde işlem yapma yeteneğine sahip oldukları için enerji gereksinimleri oldukça fazladır. Düğüm batarya ömürlerinin önemli kaynak olduğu bu ağlarda, çevreden alınan verinin işlenerek gereksiz bilgilerin atılması ile iletilen veri boyutu azaltılarak sınırlı kaynakların verimli bir şekilde kullanılması gerekmektedir. Bu çalışmada, KMAA'lar için önerilen enerji duyarlı protokoller katmanlı mimari yapısı baz alınarak incelenmiştir. Fiziksel katmandan başlanarak uygulama katmanına kadar literatürde yer alan enerji verimliliği ile ilgili çalışmalara yer verilmiştir. Bu çalışmanın hedefi, KMAA'larda geliştirilecek olan enerji verimli uygulamalar için ihtiyaç olan gereksinimlerin daha açık anlaşılmasını sağlamaktır
