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25th Signal Processing and Communications Applications Conference (SIU) -- MAY 15-18, 2017 -- Antalya, TURKEY, WOS: 000413813100430, Reverberation and multipath propagation affect the accuracy of time of flight (TOF) estimation in confined underwater medium. In this paper, time delay has been estimated by obtaining the transmitted signal and first echo signal from measured signal acquired by using a wideband transducer with 5 MHz central frequency. Cross-correlation (CC) and generalized cross-correlation (GCC) methods have been applied to the obtained signals and their performances have been compared. The results show that GCC method has better performance for time delay estimation in confined underwater medium where multipath propagation and reverberation are severe., Turk Telekom, Arcelik A S, Aselsan, ARGENIT, HAVELSAN, NETAS, Adresgezgini, IEEE Turkey Sect, AVCR Informat Technologies, Cisco, i2i Syst, Integrated Syst & Syst Design, ENOVAS, FiGES Engn, MS Spektral, Istanbul Teknik Univ

In this paper, a novel approach to near field regional focusing for non-destructive hyperthermia is presented. It is aimed to use near-field patterns of antenna arrays for non-destructive treatment by heating of cancerous tissues of the body without damaging normal tissues. Initially, near-field radiation pattern of the horn antenna array placed on the body surface is obtained with a fast and reliable method of Analytical Regularization Method (ARM) in vacuum. At the same time, this pattern of the horn antenna array placed on the body surface is simulated in layered lossy environments (i.e., skin, fat, bone, tumor tissue) by Finite Integral Method (FIM). On the next studies, a hybrid method will be constructed between ARM and Method of Moments (MoM) and near-field patterns will be focused on the tumor using of optimization algorithm. In this manner, heat destruction of tumor tissue can be achieved without damaging the healthy parts of the organ. Finally, non-destructive hyperthermia performance of the designed dual-band horn antenna array system result of the theoretical calculations will be tested on artificial organ models.

EEG (Electroencephalography) signals are used in different fields increasingly with the development of technology because they contain a lot of important information. In recent years, a great deal of these studies has been carried out about the concrete meaning of the signals. Most of these systems are called BBA (Brain Computer Interface) systems. Various applications have been developed with BBA systems. In this paper, a graphical user interface (GUI) has been designed on Matlab for the processing of recorded signals to detect blink with the help of Emotive EPOC +, which is a portable EEG device. Channel selection, filtering and averaging operations are performed by means of this software to determine the blinks. It is thought that this software will form the basis for higher level work on the Matlab platform.

Çalıştığımız ortamlardaki çevresel gürültünün seviyesi psikolojik ve fiziksel sağlığımız ve iş verimliliği açısından kritik önem taşımaktadır. Bu nedenle çevresel gürültüyü gözlemleyen sistemlere ihtiyaç duyulmaktadır. Bu bildiride, mikrofonlarla donatılmış algılayıcı düğümlerden ve katılımcı akıllı telefonlardan oluşan bir çevresel gürültü izleme ağı kullanılarak, ofis, fabrika gibi kapalı alanların tüm gün boyunca izlenmesine olanak veren bir sistem geliştirilmiştir. Sistem sayesinde çalışma ortamlarından elde edilen ses basınç seviyesi, zaman ve konum bilgileri bulut üzerindeki veri merkezlerine aktarılmış. Elde edilen veriler kullanılarak ortamların çevresel ses haritaları çıkarılmıştır. The environmental noise levels of our working areas have a critical impact on our psychological and physical health and business efficiency. Therefore; there is a need for systems that monitor environmental noise. In this paper, the sensor nodes equipped with microphones and participating smartphones are used to form an environmental noise monitoring network. This system allows monitoring of indoor areas such as offices and factories for the entire day. The sound pressure levels, which are associated with the time and location information, obtained from the work environments through the deployed network are transferred to the cloud. The resulting data are used to create noise maps of the environments. Publisher's Version

24th Signal Processing and Communication Application Conference, SIU 2016; Zonguldak; Turkey; 16 May 2016 through 19 May 2016, Bu bildiride, sınırlı geri beslemeli heterojen ağlar için veri katarı seçimi tabanlı bir girişim hizalama yöntemi sunulmuştur. Sunulan veri katarı seçimi yöntemi, veri katarlarını ilk olarak piko kullanıcılarından seçmeye başlar, daha sonra veri hızını artıran en güçlü veri katarı ile seçim işlemi devam eder ve tüm kullanıcıların en az bir veri katarının olması sağlanır. Seçim işleminden sonra, seçilen veri katarı ile diğerleri arasında oluşan girişimler ortogonal projeksiyonlarla önlenir. Sınırlı geri beslemeli kanalda toplam kapasite, uyarlanır bit paylaşımıyla iyileştirilmektedir., In this paper, a stream selection based interference alignment method is presented for heterogeneous networks with limited feedback. The presented stream selection approach initially selects streams from the user of the pico cell, continuing with the strongest streams among the unselected streams that increase the sum rate while each user receives at least one stream. After the selection procedure, the interferences between the selected stream and the unselected streams are mitigated by orthogonal projections. The sum capacity is improved by adaptive bit allocation in limited feedback channel.

24th Signal Processing and Communication Application Conference (SIU) (2016 : Zonguldak, Turkey ), In this paper, we presented a novel shape recognition framework based on medial axis graph. After extracting medial axis graph of a shape, we constructed a multi-dimensional distribution by calculating distances of each branch node to all other branch nodes in the graph. Then similarity rates between these distributions is found by using a transportation-based distance function. Finally, we compared our results with results of similar works conducted in the past., Bu bildiride, orta eksen çizgeleri (medial axis graph) kullanılarak şekil tanıma alanında yeni bir yaklaşım sunulmaktadır. İskeletleri çıkartılan şekillerin çizgelerinde, tüm kritik noktaların diger kritik noktalara olan en kısa yol uzaklığı hesaplanarak her bir şekil için çok boyutlu bir dagılım oluşturulmuştur. Önerilen şekil tanıma platformunda bu dagılımlar üzerinde taşıma tabanlı bir uzaklık fonksiyonu kullanılarak şekiller arasındaki benzerlik oranı bulunmuştur. Son olarak alınan sonuçlar daha önceden yapılmış benzer çalışmaların sonuçlarıyla karşılaştırılarak önerilen yaklaşımın başarımı gösterilmiştir.

24th Signal Processing and Communication Application Conference, SIU 2016; Zonguldak; Turkey; 16 May 2016 through 19 May 2016, Kablosuz haberleşme sistemlerinde, kanal kestirimi çok önemli bir yer tutmaktadır. Bu çalışmada A ve B, iki haberleşme düğümü olduğu varsayıldığında, A düğümünden B düğümüne olan kanal için elde edilen kanal katsayıları ile, B düğümünden A düğümüne olan kanal için elde edilen kanal katsayılarının benzerliği incelenmiştir. Karşılıklı kanal özelliğinden dolayı bu kanalların birbirine benzer çıkmaları beklenmektedir. Bu çalışmada, laboratuvar ortamında yazılım tabanlı radyo kitleri kullanılarak karşılıklı kanal özelliği test ortamında test edilmiş, bu iki kanal katsayılarının genlik ve faz ortalama değerleri karşılaştırılmıştır., Channel estimation is one of the vital processes in wireless communication systems. Assuming that A and B are two communication nodes, coefficients of the channel from A node to B node, must be very similar to the coefficients of the channel from B node to A node, due to channel reciprocity. In this paper, channel reciprocity property is tested by using software defined radio kits in laboratory environment. Average amplitude and phase values of these two channel coefficients are compared. The result of these comparisons is that the average amplitude and phase values are close.

Due to copyright restrictions, the access to the full text of this article is only available via subscription. In this paper, we investigate the performance of max-min fairness scheduler in software-defined networks (SDNs) which basically centralizes the controller after separating the control plane from the data plane of network devices. Like traditional networks, traffic control mechanism (i.e., resource allocation) plays a fundamental role to satisfy the quality of service (QoS) in SDN. Scheduler allocates the available resources to users under the consideration of some metrics such as fairness, data rate, service requirements etc. In respect to this, we provide a performance improvement of user-satisfied-ratio and quality of a real-time video service with the use of max-min fairness scheduling algorithm, which is a QoS-aware scheduler, on a network structure generated in a laptop. Additionally, the fairness issue is also considered and round robin scheduler which is the simplest resource allocation algorithm is used as benchmark in comparison. TÜBİTAK

In this paper, a computationally efficient method is proposed for modeling the indoor visible light communications (VLC) channels using a non-sequential ray tracing technique. We created three dimensional realistic simulation environment to depict indoor scenarios specifying the geometry of the indoor environment, the objects inside, the reflection characteristics of the surface materials as well as the characteristics of the transmitter and receiver. We then compute the received optical power and the delay of direct/indirect rays which are used to obtain the channel impulse response (CIR). Finally, LMS (least mean squares) and RLS (recursive least squares) iterative channel equalization techniques which are wildly employed in traditional electrical wireless communications are tested at the receiver of the VLC system. Their convergence rates as well as impacts on the BER performances are investigated by determining the optimal control parameters of these algorithms. It is concluded that for the equalizer operating with its optimal parameters, the BER performances of the VLC systems are very sensitivie to the field of view (FOV) values.

Osman, Onur (Arel Author), In this paper, we introduce a new modelling technique called Adaptive Exhaustive Search Aigorithm (AESA) to distinguish the density and to compute the accurate location in geophysical section respect to its gravity anomali. Proposed algorithm contains two step; the first one is Approximate Search Aigorithm (ASA) which allows us to find the approximate location and the other one is Exhaustive Search Aigorithm (ESA) that considers all probable model structures in the approximate region. ESA takes very long processing time. To shorten this time, here, we apply ASA, and thus, exhaustive search is more applicable. We use AESA algorithm for synthetic data, synthetic noisy data and real data from Siirt Bouguer anomali map in South-East Turkey. It is determined that the model obtained from the proposed algorithm is very close to the geological observations.

Date of Conference: 16-19 May 2016 Conference Name: IEEE 24th Signal Processing and Communications Applications Conference, SIU 2016 In this paper, a Multi-Channel/Multi-Contrast image reconstruction algorithm is proposed. The method, which is based on the Augmented Lagrangian Method uses joint convex objective functions to utilize the mutual information in the data from multiple channels to improve reconstruction quality. For this purpose, color total variation and group sparsity are used. To evaluate the performance of the method, the algorithm is compared in terms of convergence speed and image quality using Magnetic Resonance Imaging data to FCSA-MT, an alternative approach on reconstructing multi-contrast MRI data.

24th Signal Processing and Communication Application Conference, SIU 2016; Zonguldak; Turkey; 16 May 2016 through 19 May 2016, Bu bildiride modern işlemcilerin Tekil İşlem Çoklu Veri (TİÇV) komutlarıyla hızlandırılmış bir nesne takip modülü içeren mobil bir artırılmış gerçeklik uygulaması sunulmaktadır. Hem standart C++ hem de ARM işlemciler için geliştirilen TİÇV komut seti olan NEON ile kodlanmış verimli bir Sıfır Ortalamalı Farkların Kareleri Toplamı (SOFKT) yöntemi detaylandırılmıştır. Bu iki yöntemin mobil cihaz üzerinde çalışma hızları ölçülerek karşılaştırılmıştır., In this paper, we present a mobile augmented reality implementation with an accelerated tracking module using Single Instruction Multiple Data (SIMD) instructions available in modern CPUs. We detail the implementation of an efficient Zero-Mean Sum of Squared Differences (ZMSSD) algorithm both using standard C++ and the SIMD NEON instruction set of ARM processors. We compare the numerical measurements of tracking speed on a mobile device of both versions.

National Conference on Electrical, Electronics and Biomedical Engineering (ELECO) -- DEC 01-03, 2016 -- Bursa, TURKEY, WOS: 000401519800051, Observers are necessary to use in case of an urge to control a linear single input-single output system with feedback control or in a necessity to measure states of the system which are not avaliable for measurement or the high cost of the state measurements. Even though simple electrical system states are not effected very much from time delay, the mechanical systems and electrical transmission lines are more effected. To observe the states of a time delay system a time delay observer is necesarry. In this paper we have proposed a new observer for time delay systems via linearizing the delay term in the Laplace domain and we have compared the results with previous observer designs with simulations., Uludag Univ, Muhendislik Fakultesi, Elektrik Elektronik Muhendisligi Bolumu, Istanbul Teknik Univ, Elektrik Elektronik Fakultesi, TMMOB Elektrik Muhendisleri Odasi Bursa Subesi

24th Signal Processing and Communication Application Conference (SIU) (2016 : Zonguldak, TURKEY), Critical Infrastructure Security had always been an issue. With the technological advancements, there has been a continuous inflow of novel methods for critical infrastructure security. In this paper, design, implementation, and field tests of a novel critical infrastructure security system based on wireless sensor networks is presented.

24th Signal Processing and Communication Application Conference (SIU) -- MAY 16-19, 2016 -- Zonguldak, TURKEY, WOS: 000391250900110, In this paper, 11 different power quality disturbances were automatically detected by using statistical features with wavelet transform and norm entropy techniques. The best of the created features were selected with forward selection algorithm. Performance of classification algorithms, Support Vector Machines (SVM), Multi Layer Perceptron (MLP), k Nearest Neighbor (KNN) and random subspace KNN (Sub-KNN) which is an ensemble method, were examined. Consequently, the best classification accuracy of 99.3% was achieved by using Sub-KNN and it was appeared that compared to other methods, this algorithm was more robust against the noise., IEEE, Bulent Ecevit Univ, Dept Elect & Elect Engn, Bulent Ecevit Univ, Dept Biomed Engn, Bulent Ecevit Univ, Dept Comp Engn

In this paper, the design of omnidirectional and circularly polarized antennas, which can be used in satellite communication, is explained. These antennas consist of circular slotted array placed symmetrically on a cylindrical waveguide. The feeding of th Engineering, Biomedical; Engineering, Electrical & Electronic Engineering

National Conference on Electrical, Electronics and Biomedical Engineering (ELECO) -- DEC 01-03, 2016 -- Bursa, TURKEY, WOS: 000401519800020, Electric Arc Furnaces(eaf) are nonliear loads which are occured the power quality problems in electrical grids. Because of theese reasons, teh operational characteristic of EAF must be understanding very well. In this paper, Operation characteristics of MVA EAF which is located in Sivas Iron and Steel Inc. (SIDEMIR) has been examined for different EAF transformator taps. In adition to, CA 8332 power analyzer meaurements obtained from the input power in EAF and static characteristics have been compared and current values and optimal operation condations for EAF loads can be determined., Uludag Univ, Muhendislik Fakultesi, Elektrik Elektronik Muhendisligi Bolumu, Istanbul Teknik Univ, Elektrik Elektronik Fakultesi, TMMOB Elektrik Muhendisleri Odasi Bursa Subesi

Date of Conference: 16-19 May 2016 Conference Name: IEEE 24th Signal Processing and Communications Applications Conference, SIU 2016 In this paper, we offer and examine a new algorithm for sequential nonlinear regression problem. In this architecture, we use piecewise adaptive linear functions to find the nonlinear regression model sequentially. For more accurate and faster convergence, we combine a large class of piecewise linear functions. These piecewise linear functions are constructed by composing different adaptive linear functions, which are represented by the nodes of a lexicographical tree. With this tree structure, computational complexity of the algorithm is significantly reduced. To show the performance of the proposed algorithm, we present a simulation which is performed by using a well-known real data set.

In this paper a new computationally efficient and high performance channel estimation algorithm is proposed for the indoor visible light communication (VLC) sparse channels in the presence of a clipping noise. The clipping noise is modelled as a Gaussian mixture and a first time in the literature the matching pursuit (MP) and the space-alternating expectation-maximization (SAGE) algorithms are combined into the new estimation called the SAGE-MP algorithm for iteratively estimating the sparse channel coefficients as well as their positions efficiently. The MP algorithm is also employed to determine the initial values of the joint iterative algorithm. Computed simulations indicates that the SAGE-MP algorithm converge in 3 iterations at most and yields excellent bit error rate (BER) and mean-square error (MSE) performances for DC-biased optical OFDM (DCO-OFDM) based systems.

National Conference on Electrical, Electronics and Biomedical Engineering (ELECO) -- DEC 01-03, 2016 -- Bursa, TURKEY WOS: 000401519800009 Protection of power transformers take part in transmission and distribution lines is an important issue. For the reason, there are many studies which improve various methods on the subject. Among the methods, differential protection method is commonly used because of its reliability. On account of some challenging points in the method, people who study on differential protection, tries to improve the method. This paper improves a new point of view to wavelet transform based differential protection algorithm for power transformers. Uludag Univ, Muhendislik Fakultesi, Elektrik Elektronik Muhendisligi Bolumu, Istanbul Teknik Univ, Elektrik Elektronik Fakultesi, TMMOB Elektrik Muhendisleri Odasi Bursa Subesi

National Conference on Electrical, Electronics and Biomedical Engineering (ELECO) -- DEC 01-03, 2016 -- Bursa, TURKEY WOS: 000401519800015 Recently, power system stability issue has gained popularity with wind and solar energy systems beginning to effective on power systems. Faults occurring at the grid cause effective voltage drops at the output of the hybrid system consist of a photovoltaic (PV) plant and a wind farm. If the voltage decrease remains under a specific value for a long time, this may cause a large-scale voltage collapse at main grid. This paper proposes a novel method to prevent this problem by using a series dynamic braking resistor (SDBR), which is serial connected between the grid and the hybrid system, and a static var compensator (SVC) which is shunt connected at the point of common coupling (PCC). The power system with SDBR and SVC devices were modeled in MATLAB/Simulink. Also, analyses were performed in this software. Results of the analyses demonstrate the effectualness of the suggested method. Uludag Univ, Muhendislik Fakultesi, Elektrik Elektronik Muhendisligi Bolumu, Istanbul Teknik Univ, Elektrik Elektronik Fakultesi, TMMOB Elektrik Muhendisleri Odasi Bursa Subesi

Kilimci, Zeynep Hilal (Dogus Author) -- Akyokuş, Selim (Dogus Author) -- Conference full title: 24th Signal Processing and Communication Application Conference, SIU 2016; Zonguldak; Turkey; 16 May 2016 through 19 May 2016. Bu yayında esasen metin sınıflandırma alanında n-gram modeller üzerine odaklandık. N-gram modellerin sınıflandırma başarısı üzerindeki etkisini ölçmek için Naïve Bayes sınıflandırıcıya çeşitli yumuşatma yöntemlerini uyguladık. Naïve Bayes sınıflandırıcısı, metin sınıflandırmada genel olarak Bernoulli ve multinomial olmak üzere iki temel model üzerine inşa edilir. Araştırmacılar, metin sınıflandırma ve benzer alanlarda genellikle multinomial model ve Laplace yumuşatma metodunu birlikte kullanırlar. Bu çalışmanın amacı ise Naïve Bayes sınıflandırma başarısını her iki model için analiz edip n-gram modellerini farklı bir açıdan kullanarak göstermektir. İki model arasındaki çeşitli örüntüleri bulmak için deneylerimizi geniş bir Türkçe veri kümesi üzerinde yürüttük. Deney sonuçları, Bernoulli modelin uygun bir yumuşatma yöntemiyle kullanıldığında n-gram modellerin çoğunda daha iyi bir sonuç verebildiğini gösterdi. In this paper, we mainly study on n-gram models on text classification domain. In order to measure impact of n-gram models on the classification performance, we carry out Naïve Bayes classifier with various smoothing methods. Naïve Bayes classifier has generally used two main event models for text classification which are Bernoulli and multinomial models. Researchers usually address multinomial model and Laplace smoothing on text classification and similar domains. The objective of this study is to demonstrate the classification performance of event models of Naïve Bayes by analyzing both event models with different smoothing methods and using n-gram models from a different perspective. In order to find various patterns between two event models, we carry on experiments a large Turkish dataset. Experiment results indicate that Bernoulli event model with an appropriate smoothing method can outperform on most of the n-gram models.

24th Signal Processing and Communication Application Conference, SIU 2016; Zonguldak; Turkey; 16 May 2016 through 19 May 2016, Mobil uygulamaların gittikçe yaygınlaşması ile artan trafik çeşitliliği ve hacmi, ağlarda taşınan trafiğin yönetilmesi ihtiyacını kuvvetlendirdi. Yazılım tanımlı ağlar, trafik yönetimini kullanarak belirlenen gereksinimleri karşılarken, verimi maksimuma çıkararak ağları yönetebilir. Bu bildiride, ağdaki aktif anahtar sayısına dayanan güç tüketimini minimuma indiren bir yol atama algoritması öneriyoruz. Bağlantı kapasitesi kısıtlamalarını göz önüne alarak, akışların veri hacmi gereksinimlerini karşılayan en iyi yolu bulmak için genetik algoritma kullanıp, düşük karmaşıklıklı yeni bir yol atama yaklaşımı öneriyoruz. Önerilen algoritmanın verilen ağ topolojisinde çeşitli akış veri hacmi kısıtlamalarına göre performans değerlendirmelerini sunuyoruz., Since traffic diversity and volume increase with growing popularity of mobile applications, there is the strong need to manage the traffic carried by networks. Software defined networking can manage network while enabling new services by employing traffic management whose goal is to maximize the utility objective while satisfying given requirements. In this paper, we propose an efficient routing to minimize the cost based on power consumption determined by the number of active switches in a software defined networks. An optimum solution obtained by genetic algorithm and a reduced complexity routing approach are proposed while satisfying throughput requirements of flows for given constraints on link capacities in the network. We provide the performance evaluations of the proposed algorithms with respect to different throughput constraints of flows in a given network topology.

24th Signal Processing and Communication Application Conference, SIU 2016; Zonguldak; Turkey; 16 May 2016 through 19 May 2016, Bu makalede, telsiz haberleşme sistemi Tetra trunk standardı için, kullanıcıların hesapladığı C1 yol kaybı parametresi ve baz istasyonları tarafından yayınlanan baz istasyonunun yeterli kapasiteye sahip olduğu bilgisi kullanılarak, kullanıcıların en uygun baz istasyonunu ile haberleşmesini sağlayan hücre seçim algoritması önerilmiştir. Kullanıcıların hareketsiz olduğu ortamda, hücre içerisindeki farklı sayıda kullanıcılara göre benzetim sonuçları elde edilmiştir. Önerilen hücre seçim algoritmasının mesafe tabanlı hücre seçim algoritmasına göre kullanıcıların baz istasyonlarına daha adil bir şekilde dağılım sağladığı ve bağlanan kullanıcıların daha iyi sinyal karışım ve gürültü oranı değerlerine sahip oldukları gözlemlenmiştir., In this paper, we present a cell selection algorithm for Tetra trunk based professional mobile radio systems. The users are attached the base stations by considering the C1 path loss parameter and the cell load indicator broadcasted by each base station. The simulation results are obtained for various scenarios. It is observed that proposed cell selection algorithm gives better performances than distance based cell selection algorithm in terms of fair distribution of users among base stations and the signal to interference plus noise ratio belonging to attached users.

In this paper, a new optical orthogonal frequency division multiplexing (OFDM) method is proposed for multiple-input multiple-output (MIMO) visible light communications (VLC) systems. In the new scheme, non-DC biased optical OFDM (NDC-OFDM) and optical spatial modulation (OSM) methods are combined to obtain a novel optical OFDM scheme which has a better error performance. The new scheme is named as non-DC biased optical spatial modulation OFDM (NDC-OSM-OFDM). It is shown via computer simulations that the proposed scheme achieves better bit error rate (BER) performance than DC-biased optical spatial modulation OFDM (OSM-OFDM-DC), asymmetrically clipped optical spatial modulation OFDM (OSM-OFDM-AC) and NDC-OFDM.

National Conference on Electrical, Electronics and Biomedical Engineering (ELECO) -- DEC 01-03, 2016 -- Bursa, TURKEY WOS: 000401519800019 Nowadays, magnetically controlled shunt reactors (MCSRs) have been widely used to solve the problems of the power quality. MCSR can simplify the system reactive power and voltage control in the super/special high-voltage power grid, suppress power frequency and operation over voltage, eliminating generator self excitation, dynamically compensate charging the power in a transmission line, suppress the secondary arc current, damping system resonance and so on. This paper presents a comprehensive review of MCSR control strategies. It is aimed at providing a broad perspective on the status of MCSR technology to the researchers and the application engineers dealing with power quality issues. A list of more than 50 research publications on the subject is also appended for a quick reference. Uludag Univ, Muhendislik Fakultesi, Elektrik Elektronik Muhendisligi Bolumu, Istanbul Teknik Univ, Elektrik Elektronik Fakultesi, TMMOB Elektrik Muhendisleri Odasi Bursa Subesi

In this paper a reflection coefficient based transducer power gain expression has been derived which is an alternative to the impedance based expression exists in the literature. A broadband double matching problem is solved by using the derived gain expression and the obtained performance has been compared with the performance obtained via the existing expression.

Compressed sensing theory shows that any signal which is defined as sparse in a given domain can be reconstructed using fewer linear projections instead of using all Nyquist-rate samples. In this paper, we investigate basis pursuit, matching pursuit, orthogonal matching pursuit and compressive sampling matching pursuit algorithms, which are basic compressed sensing based algorithms, and present performance curves in terms of mean squared error for various parameters including signal-to-noise ratio, sparsity and number of measurements with regard to mean squared error. In addition, accuracy of estimation performances has been supported with theoretical lower bounds (Cramer-Rao lower bound and deterministic lower mean squared error). Considering estimation performances, compressive sampling matching pursuit yields the best results unless the signal has a non-sparse structure.

Süperpikseller son zamanlarda imge bölütleme ve sınıflandırma problemlerinde giderek önem kazanmaktadır. Sahne etiketlemede imge öncelikle bir süperpiksel algoritması ile görsel olarak tutarlı küçük parçalara bölütlenmekte; daha sonra süperpikseller farklı sınıflara ayrı¸stırılmaktadır. Sınıflandırma performansı kullanılan süperpiksel algoritmasının özellikleri ve parametre ayarlarından önemli ölçüde etkilenmektedir. Bu bildiride sahne etiketleme doğruluğunu iyileştirmek için birden fazla süperpiksel bölütleme sonucunu sınıflandırıcı seviyesinde kaynaştıran bir yöntem önerilmiştir. Öncelikle basit, parametrik olmayan ve eğitim gerektirmeyen SuperParsing algoritması kullanılarak süperpiksel etiketleri için olabilirlik oranları tespit edilir. Daha sonra alternatif süperpiksel bölütleme senaryoları için hesaplanan olabilirlik oranları piksel seviyesinde kaynaştırılarak, ilgili sahnenin bölütlenmesi ve etiketlenmesi tamamlanır. Önerilen yöntem 2,688 imge ve 33 etiket içeren SIFT Flow veri kümesi üzerinde test edilmiş ve SuperParsing’den daha yüksek sınıflandırma doğruluğu elde edilmiştir. Superpixels recently gained in importance in image segmentation and classification problems. In scene labeling the image is initially segmented into visually consistent small regions using a superpixel algorithm; then, superpixels are parsed into different classes. Classification performance heavily depends on the properties and parametric settings of the superpixel algorithm in use. In this paper, a method is proposed to improve scene labeling accuracy by fusing at classifier level the results of multiple superpixel segmentations. First, likelihood ratios are determined for superpixel labels using simple, nonparametric SuperParsing algorithm, which requires no training. Then, final scene segmentation and labeling is performed by pixel-level fusion of the likelihood ratios that are computed for alternative superpixel segmentation scenarios. The proposed method is tested on the SIFT Flow dataset consisting of 2,688 images and 33 labels, and is shown to outperform SuperParsing in terms of classification accuracy.

Bu bildiride karma CPU + FPGA tabanlı bir donanım mimarisi üzerinde tasarlanan Bilgisayar Destekli Semen Analizi (BDSA) sistemi genel özellikleri ile anlatılmıştır. Spermatozoa motilite analizi hareketli çoklu nesne izleme algoritmasıdır, spermatozoa morfoloji analizi için ise ard arda uygulanan çeşitli durağan görüntü işleme yöntemleri ile yapılmaktadır. Sistemimizde kullanılan ve yüksek hız gerektiren hareketli ve durağan görüntü işleme işlevleri için FPGA yapısının paralel işlem yeteneğinden yararlanılmıştır. Çeşitli hesaplamalar ise geliştirilen özel yazılım ile CPU üzerinde gerçeklenmiştir. Biyolojik mikroskoba takılabilen bir HD dijital kamerayı da içermekte olan sistemimizin esnek programlanabilen ve tek başına çalışabilen bir akıllı sistem olarak çalışması da öngörülmüştür. In this paper a Computer Assisted Semen Analysis (CASA) system designed on a hybrid CPU + FPGA hardware platform is presented. Multiple moving object tracking technique is used for spermatozoa motility analysis and an algorithm consisting of compositely applied various image processing techniques is used for spermatozoa morphology analysis. The parallel processing architecture of FPGA's are utilized for the image and video processing functions that our system use where high speed processing power is required. Various calculations are done on CPU by utilizing developed software. Our system incorporates also an HD digital camera which is mounted on a biological microscope. It has also been foreseen that our system will be a standalone intelligence system and flexibly programmable for different jobs. Publisher's Version

Conference name: 23rd Signal Processing and Communications Applications Conference, SIU 2015 Date of Conference: 16-19 May 2015 Hiperspektral hedef tespiti için yürütülen çalışmalar genel olarak iki sınıfta degerlendirilebilir. İlk sınıf olan anomali tespit yöntemlerinde, hedefin görüntünün geri kalanından farklı oldugu bilgisi kullanılarak görüntü analiz edilmektedir. Diğer sınıfta ise daha önceden bilgisi edinilmiş hedefe ait spektral imza ile görüntüdeki herbir piksel arasındaki benzerlik bulunarak hedefin konumu tespit edimektedir. Her iki sınıf yöntemin de önemli bir dezavantajı hiperspektral görüntü piksellerini bagımsız olarak degerlendirip, aralarındaki komşuluk ilişkilerini gözardı etmesidir. Bu makalede anomali tespit ve imza tabanlı tespit yakla¸sımlarını, pikseller arası komşuluk ilişkilerini de göz önünde bulundurarak birleştiren çizge yaklaşımına dayalı yeni bir yöntem önerilmiştir. Hedeflerin hem imza bilgisine sahip olundugu hem de anomali sayılabilecek ölçülerde olduğu varsayılarak önerilen çizge yaklaşımında önplan için imza bilgisi kullanan özgün bir türev tabanlı uyumlu filtre önerilmiştir. Arkaplan için ise seyreklik bilgisi kullanarak Gauss karışım bileşeni kestirimi yapan yeni bir anomali tespit yöntemi geliştirilmiştir. Son olarak komşular arası benzerligi tanımlamak için ise spektral bir benzerlik ölçütü olan spektral açı eleştiricisi kullanılmıştır. Önerilen çizge tabanlı yöntemin önplan, arkaplan ve komşuluk ilişkilerini uygun şekilde birleştirdigi ve önceki yöntemlere göre hedefi gürültüden arınmış bir bütün şeklinde başarıyla tespit edebildigi gözlemlenmiştir. The studies on hyperspectral target detection until now, has been treated in two approaches. Anomaly detection can be considered as the first approach, which analyses the hyperspectral image with respect to the difference between target and the rest of the hyperspectral image. The second approach compares the previously obtained spectral signature of the target with the pixels of the hyperspectral image in order to localize the target. A distinctive disadvantage of the aforementioned approaches is to treat each pixel of the hyperspectral image individually, without considering the neighbourhood relations between the pixels. In this paper, we propose a target detection algorithm which combines the anomaly detection and signature based hyperspectral target detection approaches in a graph based framework by utilizing the neighbourhood relations between the pixels. Assuming that the target signature is available and the target sizes are in the range of anomaly sizes, a novel derivative based matched filter is first proposed to model the foreground. Second, a new anomaly detection method which models the background as a Gaussian mixture is developed. The developed model estimates the optimal number of components forming the Gaussian mixture by means of utilizing sparsity information. Finally, the similarity of the neighbouring hyperspectral pixels is measured with the spectral angle mapper. The overall proposed graph based method has successfully combined the foreground, background and neighbouring information and improved the detection performance by locating the target as a whole object free from noises. © 2015 IEEE.

Date of Conference: 16-19 May 2015 Conference name: 23nd Signal Processing and Communications Applications Conference (SIU), 2015 Çok yollu sönümlenme mekanizması, 10 GHz altındaki frekanslarda çalışan sabit karasal mikrodalga görüş çizgisi radyo linkleri için belirleyici yayılım faktörüdür. Çok yollu yayılımdan dolayı sönümlenme karasal görüş çizgisi linklerdeki alınan sinyalleri zayıflamakta ve dolayısıyla noktadan-noktaya sistemlerin performasını bozmaktadır. Çeşitli metodlar; çeşitleme ile yada çeşitleme tekniği olmadan çok yollu sönümlenmenin etkilerini azaltmak için kullanılır. Uzay çeşitlemede dikey aralık çok yollu sönümlenmeyi azaltmanın en etkili metodlarından biridir. Bu makalede, sabit karasal mikrodalga görüş çizgisi radyo linkleri için iki anten uzay çeşitleme konfigürasyonu konseptinin değerlendirilmesi yapılmıştır. Arazi hat profili boyunca yerden yansıma noktalarından kaynaklanan çok yolluluktan dolayı çok yollu sönümlenme olayları analiz edilmiştir. Örnek sabit karasal mikrodalga görüş çizgisi radyo linklerindeki farklı anten yerden yüksekliklerinde iki anten konfigürasyonu ile uzaysal çeşitleme benzetim çalışması yapılmıştır. Benzetim sonuçları alıcıdaki güç seviyesine göre degerlendirilmiştir. Multipath fading is the dominant propagation factor for fixed terrestrial microwave line-of-sight (LOS) radio links operating at frequencies below 10 GHz. Fading due to multipath propagation attenuates received signals on line-of-sight links and thereby impair the performance of point-to-point systems. Several methods are used to reduce the effects of multipath fading without or with the need for diversity. Antenna spacing in spacing diversity is one of the most effective methods of mitigating multipath fading. This paper provides an evaluation of the concept of two antenna space-diversity configuration for fixed terrestrial microwave line-of-sight radio links. Multipath fading events due to multipath arising from ground reflection points have been analysed along the terrain path profile. A spatial diversity with two antenna configuration in different antenna heights above ground level is simulated over sample fixed terrestrial microwave line-of-sight radio links. The results have been evaluated in terms of the available signal power at the receiver. © 2015 IEEE.

In this paper a new algorithm based on busy tone approach has been proposed for the coexistence of IEEE 802.22 and IEEE 802.11af systems in TV white space. Different from the earlier study in addition to 802.11af access points listening to the busy tone signal their clients also listen to the busy tone and let the access points know once they hear it. Accordingly interference caused to 802.22 systems has been reduced. This study quantifies the improved system performance in terms of interfering packet rate for different hearing regions considering the communication parameters and channel models adapted for the standards.

Date of Conference: 16-19 May 2015 Conference Name: 23nd Signal Processing and Communications Applications Conference, SIU 2015 A new multi-resolution super-pixel based algorithm is proposed to track cell size, count and motion in Mesenchymal Stem Cells (MSCs) images. Multi-resolution super-pixels are obtained by placing varying density seeds on the image. The density of the seeds are determined according to the local high frequency components of the MSCs image. In this way a multi-resolution super-pixels decomposition of the image is obtained. A second contribution of the paper is novel decision rule for merging similar neighboring super-pixels. An algorithm based on well known wavelet decomposition is developed and applied to the histograms of neighboring super pixels to exploit similarity. The proposed algorithm is experimentally shown to be successful in segmenting and tracking cells in MSCs images.

23nd Signal Processing and Communications Applications Conference (SIU) -- MAY 16-19, 2015 -- Inonu Univ, Malatya, TURKEY WOS: 000380500900192 Superpixels recently gained in importance in image segmentation and classification problems. In scene labeling the image is initially segmented into visually consistent small regions using a superpixel algorithm; then, superpixels are parsed into different classes. Classification performance heavily depends on the properties and parametric settings of the superpixel algorithm in use. In this paper, a method is proposed to improve scene labeling accuracy by fusing at classifier level the results of multiple superpixel segmentations. First, likelihood ratios are determined for superpixel labels using simple, nonparametric SuperParsing algorithm, which requires no training. Then, final scene segmentation and labeling is performed by pixel-level fusion of the likelihood ratios that are computed for alternative superpixel segmentation scenarios. The proposed method is tested on the SIFT Flow dataset consisting of 2,688 images and 33 labels, and is shown to outperform SuperParsing in terms of classification accuracy. Dept Comp Engn & Elect & Elect Engn, Elect & Elect Engn, Bilkent Univ

23nd Signal Processing and Communications Applications Conference (SIU) -- MAY 16-19, 2015 -- Inonu Univ, Malatya, TURKEY, WOS: 000380500900101, In this paper, a route planning application has been developed for mobile devices. The goal was to select the algorithm that computes the route in the shortest amount of time. To this end, a database containing information and high-resolution pictures of the touristic locations in Eskisehir province have been created. For each interest point in the database, optimal routes have been computed using such complete search algorithms as A* and Ant Colonial Optimization found in the literature. The experimental work has shown that A* algorithm runs up to 80% faster than the Ant Colonial Optimization as the number of interest points increases., Dept Comp Engn & Elect & Elect Engn, Elect & Elect Engn, Bilkent Univ

Date of Conference: 16-19 May 2015 Recent advances in mobile device technology have turned the mobile phones into powerfull devices with high resolution cameras and fast processing capabilities. Having more user interaction potential compared to regular PCs, mobile devices with cameras can enable richer content-based object image queries: the user can capture multiple images of the query object from different viewing angles and at different scales, thereby providing much more information about the object to improve the retrieval accuracy. The goal of this paper is to improve the mobile image retrieval performance using multiple query images. To this end, we use the well-known bag-of-visual-words approach to represent the images, and employ early and late fusion strategies to utilize the information in multiple query images. With extensive experiments on an object image dataset with a single object per image, we show that multi-image queries result in higher average precision performance than single image queries. © 2015 IEEE.

23nd Signal Processing and Communications Applications Conference (SIU) -- MAY 16-19, 2015 -- Inonu Univ, Malatya, TURKEY WOS: 000380500900337 In this paper a Computer Assisted Semen Analysis (CASA) system designed on a hybrid CPU + FPGA hardware platform is presented. Multiple moving object tracking technique is used for spermatozoa motility analysis and an algorithm consisting of compositely applied various image processing techniques is used for spermatozoa morphology analysis. The parallel processing architecture of FPGA's are utilized for the image and video processing functions that our system use where high speed processing power is required. Various calculations are done on CPU by utilizing developed software. Our system incorporates also an HD digital camera which is mounted on a biological microscope. It has also been foreseen that our system will be a standalone intelligence system and flexibly programmable for different jobs. Dept Comp Engn & Elect & Elect Engn, Elect & Elect Engn, Bilkent Univ

In this paper a new grounded capacitance multiplier using two Voltage Differencing Current Conveyors (VDCCs), two resistors, and one grounded capacitor is presented. The proposed capacitance multiplier can be tuned electronically by changing the biasing current of the VDCC. Moreover, the circuit does not require any conditions of component matching. The performance of the proposed capacitance multiplier is verified, and simulated by using PSPICE with TSMC CMOS 0.18 μm process parameters. © 2015 IEEE.

19th National Biomedical Engineering Meeting (BIYOMUT) -- NOV 05-06, 2015 -- -- Istanbul, TURKEY, WOS: 000380507300012, Electroencephalogram (EEG)-based emotion recognition is a rapidly growing field. This paper presents a research study on identifying the changes caused by human emotions in brain signals through EEG records and further examines the availability of chaotic analysis for emotion prediction applications. We designed an efficient presentation including 30 pictures from International Affective Picture System (IAPS) which could stimulate the emotions of happiness, sadness and fear. A group of 20 persons consisting of 12 males and 8 females took place in our research study as subjects voluntarily. In order to acquire the EEG signals under picture induction environment, a total of 30 pictures that might reveal the feelings of happiness, sadness and fear were shown to the volunteer subjects that participated in the study voluntarily. Data acquired from EEG records were analyzed by using chaotic analysis through MATLAB program and two different attributes consisting of "Largest Lyapunov Exponent (LLE)" and "Correlation Dimension" were obtained. The mean values of each attribute that obtained through chaotic analysis were compared by using independent t-test and dependent t-test in SPSS program with 95% confidence interval and a P value of p