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Publication Metadata only PREPARATION, STRUCTURE, AND MAGNETIC PROPERTIES OF CuMnFe2O4 NANOPARTICLES FOR MAGNETIC PARTICLE IMAGING(IEEE, 2013) Dogan, N.; Bingolbali, A.; Arda, L.; Asilturk, M.; Gebze Technical University; University of California System; University of California Berkeley; Yildiz Technical University; Bahcesehir University; Akdeniz UniversityPublication Metadata only Energy scaling of a multipass-cavity mode-locked femtosecond bulk laser with a carbon nanotube saturable absorber(SPIE-INT SOC OPTICAL ENGINEERING, 2013) Baylam, I.; Ozharar, S.; Cankaya, H.; Choi, S. Y.; Kim, K.; Rotermund, F.; Griebner, U.; Petrov, V.; Sennaroglu, A.; Clarkson, WA; Shori, RK; Koc University; Bahcesehir University; Ajou University; Ajou University; Leibniz Association; Max Born Institute for Nonlinear Optics & Short Term SpectroscopyIn the design of mode-locked lasers, single-walled carbon nanotube saturable absorbers (SWCNT-SAs) have emerged as important alternatives to semiconductor saturable absorber mirrors (SESAMs) due to their favorable optical characteristics, low cost, and relatively simple fabrication scheme. Therefore, it is of great interest to explore the limits of energy scaling in solid-state lasers mode-locked with SWCNT-SAs. Due to their unique wavelength range for biomedical applications, a room-temperature Cr4+:forsterite laser operating near 1.3 mu m was used in the mode-locking experiments. The laser was end-pumped with a continuous-wave Yb-fiber laser at 1064 nm. Furthermore, a q-preserving multipass-cavity (MPC) was added to the short resonator to lower the pulse repetition rate to 4.51 MHz and to scale up the output pulse energy at low average power. The SWCNT-SA was fabricated with SWCNTs grown by the high-pressure CO conversion (HiPCO) technique. With dispersion compensation optics, the net group delay dispersion of the resonator was estimated to be around -4440 fs(2). When mode-locked with the SWCNT-SA, the resonator produced 10-nJ, 121-fs pulses at 1247 nm with a spectral bandwidth of 16 nm, corresponding to a time-bandwidth product of 0.37. To our knowledge, this represents the highest peak power (84 kW) generated to date from a bulk femtosecond solid-state laser, mode-locked by using a SWCNT-SA. The results also suggest that the peak power achieved in our experiments was limited only by the self-focusing in the Cr4+:forsterite gain medium and further increase in output energy should in principle be possible in other gain media mode-locked with SWCNT-SAs.Publication Metadata only Automatic melodic segmentation of Turkish makam music scores(IEEE, 2014) Bozkurt, Baris; Karaali, Bilge; Karaosmanoglu, M. Kemal; Unal, Erdem; Bahcesehir University; Izmir Institute of Technology; Yildiz Technical University; Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)Automatic melodic segmentation is one of the important steps in computational analysis of melodic content from symbolic data This widely studied research problem has been very rarely considered for Turkish makam music. In this paper we first present test results for state-of-the-art techniques from literature on Turkish makam music data Then, we present a statistical classification-based segmentation system that exploits the link between makant melodies and usul and makam scale hierarchies together with the well-known features in literature. We show through tests on a large dataset that the proposed system has a higher accuracy.Publication Metadata only Dendritic Spine Shape Classification from Two-Photon Microscopy Images(IEEE, 2015) Ghani, Muhammad Usman; Kanik, Sumeyra Demir; Argunsah, Ali Ozgur; Tasdizen, Tolga; Unay, Devrim; Cetin, Mujdat; Sabanci University; Fundacao Champalimaud; Utah System of Higher Education; University of Utah; Bahcesehir UniversityFunctional properties of a neuron are coupled with its morphology, particularly the morphology of dendritic spines. Spine volume has been used as the primary morphological parameter in order the characterize the structure and function coupling. However, this reductionist approach neglects the rich shape repertoire of dendritic spines. First step to incorporate spine shape information into functional coupling is classifying main spine shapes that were proposed in the literature. Due to the lack of reliable and fully automatic tools to analyze the morphology of the spines, such analysis is often performed manually, which is a laborious and time intensive task and prone to subjectivity. In this paper we present an automated approach to extract features using basic image processing techniques, and classify spines into mushroom or stubby by applying machine learning algorithms. Out of 50 manually segmented mushroom and stubby spines, Support Vector Machine was able to classify 98% of the spines correctly.Publication Metadata only Deciding which technology is the best for distance education: Issues in media/technology comparisons studies(ELSEVIER SCIENCE BV, 2011) Yengin, Ilker; Karahoca, Adem; Karahoca, Dilek; Uzunboylu, Huseyin; Karahoca, A; Kanbul, S; University of Nebraska System; University of Nebraska Lincoln; Bahcesehir University; Near East UniversityDistance education decision makers, who will be shaping the future of distance education, should understand the role of different technologies and their unique attributes closely. In order to achieve this task accurately, they also need to know the superiorities of different technologies to each other. Media comparison studies have been conducted to see these superiorities and to help deciding which technology is better? In some studies researchers make some fundamental errors and flaws in media comparison studies for distance learning. Hence, there is a need to determine these issues in order to make decision process work better. In this review study, issues on media comparison studies in distance education discussed with theoretical backgrounds. Also in this study, reader could find what kind of flaws can occur in media comparisons studies and what cause to these flaws as well as some suggestions to avoid these flaws. In this study, five of the most significant errors scholars have made in writing and discussing distance education research in technology/media comparisons studies are determined. This study aims to help distance education policy makers, distance education researchers and instructors by making them aware of these issues in comparison studies. Hence, they could make a more accurate decision when implementing distance learning solutions in their institutions. (C) 2010 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Guest Editor.Publication Metadata only A JOINT CLASSIFICATION AND SEGMENTATION APPROACH FOR DENDRITIC SPINE SEGMENTATION IN 2-PHOTON MICROSCOPY IMAGES(IEEE, 2015) Erdil, Ertunc; Argunsah, A. Ozgur; Tasdizen, Tolga; Unay, Devrim; Cetin, Mujdat; Sabanci University; Fundacao Champalimaud; Utah System of Higher Education; University of Utah; Bahcesehir UniversityShape priors have been successfully used in challenging biomedical imaging problems. However when the shape distribution involves multiple shape classes, leading to a multimodal shape density, effective use of shape priors in segmentation becomes more challenging. In such scenarios, knowing the class of the shape can aid the segmentation process, which is of course unknown a priori. In this paper, we propose a joint classification and segmentation approach for dendritic spine segmentation which infers the class of the spine during segmentation and adapts the remaining segmentation process accordingly. We evaluate our proposed approach on 2-photon microscopy images containing dendritic spines and compare its performance quantitatively to an existing approach based on nonparametric shape priors. Both visual and quantitative results demonstrate the effectiveness of our approach in dendritic spine segmentation.Publication Metadata only Is SMS Still Alive For Education: Analysis Of Educational Potentials Of SMS technology?(ELSEVIER SCIENCE BV, 2011) Yengin, Ilker; Karahoca, Adem; Karahoca, Dilek; Uzunboylu, Huseyin; Karahoca, A; Kanbul, S; University of Nebraska System; University of Nebraska Lincoln; Bahcesehir University; Near East UniversityMobile phone, especially SMS concept is a fairly old technology. In spite of the fact that there are some applications of using SMS capabilities of mobile phones in education, the usage is not widely in all educational areas. Still, there is a need to understand how SMS technology could be applicable for education in different ways. Hence, in this study, authors' investigate possible educational use of SMS by providing a detailed analysis of the technology and examples of different research studies of successful implementations in education. This study may be a guide for school administrators and policy makers to understand educational technology potential of SMS by providing benefits and drawbacks of the technology. (C) 2010 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Guest Editor.Publication Metadata only Motor Condition Monitoring by Empirical Wavelet Transform(IEEE COMPUTER SOC, 2018) Eren, Levent; Cekic, Yalcin; Devaney, Michael J.; Izmir Ekonomi Universitesi; Bahcesehir University; University of Missouri System; University of Missouri ColumbiaBearing faults are by far the biggest single source of motor failures. Both fast Fourier (frequency based) and wavelet (time-scale based) transforms are used commonly in analyzing raw vibration or current data to detect bearing faults. A hybrid method, Empirical Wavelet Transform (EWT), is used in this study to provide better accuracy in detecting faults from bearing vibration data. In the proposed method, the raw vibration data is processed by fast Fourier transform. Then, the Fourier spectrum of the vibration signal is divided into segments adaptively with each segment containing part of the frequency band. Next, the wavelet transform is applied to all segments. Finally, inverse Fourier transform is utilized to obtain time domain signal with the frequency band of interest from EWT coefficients to detect bearing faults. The bearing fault related segments are identified by comparing rms values of healthy bearing vibration signal segments with the same segments of faulty bearing. The main advantage of the proposed method is the possibility of extracting the segments of interest from the original vibration data for determining both fault type and severity.Publication Metadata only Motor Current Signature Analysis via M-Channel FIR Cosine-Modulated Filter Banks(IEEE, 2011) Eren, Levent; Devaney, Michael J.; Ertan, HB; Bahcesehir University; University of Missouri System; University of Missouri ColumbiaMotor current signature analysis (NICSA) provides a method for non-intrusive and continuous monitoring of motors in many applications. Initially, the fast Fourier transform (FFT) was the main signal processing method used in such analysis. Recently, wavelet packet decomposition (WPD) has become popular in such applications. The second approach gives better results in the case of non-stationary signals but it has much higher computational complexity limiting its use with real time power quality monitoring devices. Use of four-channel FIR cosine-modulated filter banks is proposed in this study to provide lower computational complexity.Publication Metadata only Coupled Shape Priors for Dynamic Segmentation of Dendritic Spines(IEEE, 2017) Atabakilachini, Naeimeh; Erdil, Ertunc; Argunsah, A. Ozgur; Rada, Lavdie; Unay, Devrim; Cetin, Mujdat; Sabanci University; University of Zurich; Bahcesehir University; Izmir Ekonomi UniversitesiSegmentation of biomedical images is a challenging task, especially when there is low quality or missing data. The use of prior information can provide significant assistance for obtaining more accurate results. In this paper we propose a new approach for dendritic spine segmentation from microscopic images over time, which is motivated by incorporating shape information from previous time points to segment a spine in the current time point. In particular, using a training set consisting of spines in two consecutive time points to construct coupled shape priors, and given the segmentation in the previous time point, we can improve the segmentation process of the spine in the current time point. Our approach has been evaluated on 2-photon microscopy images of dendritic spines and its effectiveness has been demonstrated by both visual and quantitative results.