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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only Robust speech recognition using adaptively denoised wavelet coefficients(IEEE, 2004) Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; N/A; Tekalp, Ahmet Murat; Erzin, Engin; Akyol, Emrah; Faculty Member; Faculty Member; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; 26207; 34503; N/AThe existence of additive noise affects the performance of speech recognition in real environments. We propose a new set of feature vectors for robust speech recognition using denoised wavelet coefficients. The use of wavelet coefficients in speech processing is motivated by the ability of the wavelet transform to capture both time and frequency information and the non-stationary behaviour of speech signals. We use one set of noisy data, such as data with car noise, and we use hard thresholding in the best basis for denoising. We use isolated digits as our database in our HMM based speech recognition system. A performance comparison of hard thresholding denoised wavelet coefficients and MFCC feature vectors is presented.Publication Metadata only Optimal rate and input format control for content and context adaptive video streaming(IEEE, 2004) Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; N/A; Tekalp, Ahmet Murat; Civanlar, Mehmet Reha; Özçelebi, Tanır; Faculty Member; Faculty Member; PhD Student; Department of Electrical and Electronics Engineering; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; 26207; 16372; N/AA novel dynamic programming based technique for optimal selection of input video format and compression rate for video streaming based on "relevancy" of the content and user context is presented. The technique uses context dependent content analysis to divide the input video into temporal segments. User selected relevance levels assigned to these segments are used in formulating a constrained optimization problem, which is solved using dynamic programming. The technique minimizes a weighted distortion measure and the initial waiting time for continuous playback under maximum acceptable distortion constraints. Spatial resolution and frame rate of input video and the DCT quantization parameters are used as optimization variables. The technique is applied to encoding of soccer videos using an H.264 [1] encoder. The improvements obtained over a standard H.264 implementation are demonstrated by experimental results.Publication Metadata only An extended family of bounded component analysis algorithms(IEEE Computer Society, 2015) Department of Electrical and Electronics Engineering; N/A; Erdoğan, Alper Tunga; İnan, Hüseyin Atahan; Faculty Member; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; 41624; N/ABounded Component Analysis (BCA) is a recent concept proposed as an alternative method for Blind Source Separation problem. BCA enables the separation of dependent as well as independent sources from their mixtures under the practical assumption on source boundedness. This article extends the optimization setting of a recent BCA approach which can be used to produce a variety of BCA algorithms. The article also provides examples of objective functions and the corresponding iterative algorithms. The numerical examples illustrate the advantages of proposed BCA examples regarding the correlated source separation capability over the state of the art ICA based approaches. 1 © 2014 IEEE.Publication Metadata only E_coach(IEEE, 2004) Department of Electrical and Electronics Engineering; Department of Computer Engineering; Civanlar, Mehmet Reha; Baykan, Eda; Faculty Member; Undergraduated Student; Department of Electrical and Electronics Engineering; Department of Computer Engineering; College of Engineering; College of Engineering; 16372; N/AWe developed the necessary software to control the playback speed of exercise videos playing on a personal computer, using the heart rate of an individual performing the recorded exercise routine. Moderate exercise, at an appropriate heart rate, is widely regarded today as an excellent way to improve one's health when performed on a regular and frequent basis. One popular form of an indoor exercise program is to use a video "workout" program of aerobic exercise and/or weight training exercises. The "off-the-shelf" exercise videos, while they may target various fitness levels (such as "beginner", "regular", and "advanced"), cannot offer precise adjustments to address each user's current fitness level. The software developed allows for the playback of an exercise video to be adjusted to accommodate the fitness level of the individual user through a closed loop feedback mechanism. The project is being improved for logging and analyzing the performance of an individual who uses the system regularly and for exercise planning. The closed loop feedback mechanism that models the relationship between the heart rate and exercise level, is being improved with the experiments in which subjects incude fit people as well as ones who are sedementary. © 2004 IEEE.Publication Metadata only Batch fabrication of self-assembled nickel-iron nanowires by electrodeposition(IEEE, 2006) N/A; Department of Electrical and Electronics Engineering; Department of Mechanical Engineering; Şardan, Özlem; Yalçınkaya, Arda Deniz; Alaca, Burhanettin Erdem; Master Student; Researcher; Faculty Member; Department of Electrical and Electronics Engineering; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 144523; 115108Lack of batch-compatible fabrication techniques can be considered as the most important challenge in the integration of nanostructures with microelectromechanical systems (MEMS). a solution to the micro-nano integration problem is offered by introducing a batch-compatible nanowire fabrication technique based on basic lithographic techniques and guided self-assembly. the basic principle is obtaining cracks at predetermined locations in a sacrificial SiO2 layer on Si and filling these cracks with a suitable metal by electrodeposition. the technique is demonstrated by using Nickel-Iron as the deposition material and verifying the magnetic behavior of resulting nanowires.Publication Metadata only Rate-delay tradeoff with network coding in molecular nanonetworks(IEEE-Inst Electrical Electronics Engineers Inc, 2013) N/A; N/A; Department of Electrical and Electronics Engineering; Ünlütürk, Bige Deniz; Malak, Derya; Akan, Özgür Barış; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 6647Molecular communication is a novel nanoscale communication paradigm, in which information is encoded in messenger molecules for transmission and reception. However, molecular communication is unreliable and has highly varying long propagation delays mainly due to the stochastic behavior of the freely diffusing molecules. Thus, it is essential to analyze its delay characteristics, as well as the tradeoff between the rate and delay, in order to reveal the capabilities and limitations of molecular information transmission in nanonetworks. In this paper, first, a new messenger-based molecular communication model, which includes a nanotransmitter sending information to a nanoreceiver, is introduced. The information is encoded on a polyethylene molecule, CH3(CHX)(n)CH2F, where X stands for H and F atoms representing 0 and 1 bits, respectively. The emission of the molecules is modeled by puffing process which is inspired by the alarm pheromone release by animals in dangerous situations. In this work, the rate-delay characteristics of this messenger-based molecular communication model are explored. Then, a Nano-Relay is inserted in the model, which XOR's the incoming messages from two different nanomachines. Performance evaluation shows that indeed, a simple network coding mechanism significantly improves the rate given delay of the system, and vice versa.Publication Metadata only Comparison of phoneme and viseme based acoustic units for speech driven realistic lip animation(IEEE, 2007) Bozkurt, Elif; Erdem, Çiǧdem Eroǧlu; Erdem, Tanju; Özkan, Mehmet; Department of Computer Engineering; Erzin, Engin; Faculty Member; Department of Computer Engineering; College of Engineering; 34503Natural looking lip animation, synchronized with incoming speech, is essential for realistic character animation. In this work, we evaluate the performance of phone and viseme based acoustic units, with and without context information, for generating realistic lip synchronization using HMM based recognition systems. We conclude via objective evaluations that utilization of viseme based units with context information outperforms the other methods./ Öz: Konuşma ile senkronize ve doğal görünen dudak hareketlerinin üretilmesi, gerçekçi karakter animasyonu için önemli bir problemdir. Bu çalışmada, gerçekçi dudak hareketleri üretebilmek için Saklı Markov Modeli (SMM) kullanarak, fonem ve vizem temelli akustik birimlerin başarımlarını karşılaştırıyoruz. Nesnel değerlendirmeler sonucunda, komşuluk bilgisini kullanan vizem temelli akustik birimlerin diğer metodlardan daha üstün olduğunu gösteriyoruz.Publication Metadata only Comb- actuated resonant torsional scanner for microdisplays(IEEE, 2009) Department of Electrical and Electronics Engineering; N/A; Department of Electrical and Electronics Engineering; Ürey, Hakan; Gökçe, Sertan Kutal; Holmstrom, Sven; Arslan, Aslıhan; Faculty Member; Master Student; Researcher; Master Student; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; 8579; N/A; N/A; N/AA comb-actuated 1D torsional MEMS scanner is developed for high resolution projection display systems using mechanical coupling principle. 64° TOSA (total optical scan angle) is achieved at 22.1 kHz with 170 V peak-to-peak excitation voltages.Publication Metadata only Evaluation of audio features for audio-visual analysis of dance figures(IEEE, 2008) Department of Electrical and Electronics Engineering; Department of Computer Engineering; Department of Computer Engineering; Tekalp, Ahmet Murat; Erzin, Engin; Yemez, Yücel; Demir, Yasemin; Faculty Member; Faculty Member; Faculty Member; Master Student; Department of Electrical and Electronics Engineering; Department of Computer Engineering; College of Engineering; College of Engineering; College of Engineering; Graduate School of Sciences and Engineering; 26207; 34503; 107907; N/AWe present a framework for selecting best audio features for audio-visual analysis and synthesis of dance figures. Dance figures are performed synchronously with the musical rhythm. They can be analyzed through the audio spectra using spectral and rhythmic musical features. In the proposed audio feature evaluation system, dance figures are manually labeled over the video stream. The music segments, which correspond to labeled dance figures, are used to train hidden Markov model (HMM) structures to learn spectral audio patterns for the dance figure melodies. The melody recognition performances of the HMM models for various spectral feature sets are evaluated. Audio features, which are maximizing dance figure melody recognition performances, are selected as the best audio features for the analyzed audiovisual dance recordings. In our evaluations, mel-scale cepstral coefficients (MFCC) with their first and second derivatives, spectral centroid, spectral flux and spectral roll-off are used as candidate audio features. Selection of the best audio features can be used towards analysis and synthesis of audio-driven body animation.Publication Metadata only Competitive randomized nonlinear prediction under additive noise(IEEE-Inst Electrical Electronics Engineers Inc, 2010) N/A; Department of Electrical and Electronics Engineering; Yılmaz, Yasin; Kozat, Süleyman Serdar; Master Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 177972We consider sequential nonlinear prediction of a bounded, real-valued and deterministic signal from its noise-corrupted past samples in a competitive algorithm framework. We introduce a randomized algorithm based on context-trees [1]. The introduced algorithm asymptotically achieves the performance of the best piecewise affine model that can both select the best partition of the past observations space (from a doubly exponential number of possible partitions) and the affine model parameters based on the desired clean signal in hindsight. Although the performance measure including the loss function is defined with respect to the noise-free clean signal, the clean signal, its past samples or prediction errors are not available for training or constructing predictions. We demonstrate the performance of the introduced algorithm when applied to certain chaotic signals.