WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Conference Object Speckle Intensity Correlation Distribution Analysis Based on Coincidence Detection for Scattering Medium Characterization(IEEE, 2025) Yoldas, Cansu; Kisa, Alperen; Atac, Enes; Karatay, Anil; Dinleyici, Mehmet SalihCharacterizing a scattering medium is essential for understanding and controlling light propagation, enabling accurate imaging, correlation analysis, and material diagnostics in scientific applications. In this study, the scattering medium has been characterized by examining the spatial distribution of the second-order temporal correlation function of varying speckle patterns obtained under faint-light conditions using a charge-coupled device (CCD) camera. In the proposed method, the exposure time has been utilized as a self-coincidence circuit of the CCD. The spatial statistics of second-order temporal autocorrelation values have been analyzed through power spectral density and radial spatial autocorrelation function. The scattering degree of the medium has been determined using our proposed autocorrelation-based metric. The results from three different media have shown that the method is effective and holds potential for applications such as characterization through speckle imaging.Article Citation - WoS: 2Evaluation of Malassezia Species by Fourier Transform Infrared (ft-Ir) Spectroscopy(Ankara Microbiology Society, 2011) Ergin, Çağrı; Vuran, M. Emre; Gök, Yaşar; Özdemir, Durmuş; Karaarslan, Aydın; Kaleli, İlnur; Çon, Ahmet HilmiMalassezia species which are lipophilic exobasidiomycetes fungi, have been accepted as members of normal cutaneous flora as well as causative agent of certain skin diseases. In routine microbiology laboratory, species identification based on phenotypic characters may not yield identical results with taxonomic studies. Lipophilic and lipid-dependent Malassezia yeasts require lipid-enriched complex media. For this reason, Fourier transform infrared (FT-IR) spectroscopy analysis focused on lipid window may be useful for identification of Malassezia species. In this study, 10 different standard Malassezia species (M.dermatis CBS 9145, M.furfur CBS 7019, M.japonica CBS 9432, M.globosa CBS 7966, M.nana CBS 9561, M.obtusa CBS 7876, M.pachydermatis CBS 1879, M.slooffiae CBS 7956, M.sympodialis CBS 7222 and M.yamatoensis CBS 9725) which are human pathogens, have been analyzed by FT-IR spectroscopy following standard cultivation onto modified Dixon agar medium. Results showed that two main groups (M1; M.globosa, Robtusa, M.sympodialis, M.dermatis, M.pachydermatis vs, M2; M.furfur, M.japonica, M.nana, M.slooffiae, M.yamatoensis) were discriminated by whole spectra analysis. M.obtusa in M1 by 1686-1606 cm(-1) wavenumber ranges and M.japonicum in M2 by 2993-2812 cm(-1) wavenumber ranges were identified with low level discrimination power. Discriminatory areas for species differentiation of M1 members as M.sympodialis, M.globosa and M.pachydermatis and M2 members as M.furfur and M.yamatoensis could not be identified. Several spectral windows analysis results revealed that FT-IR spectroscopy was not sufficient for species identification of culture grown Malassezia species.Article Citation - WoS: 7Influence of Drying Temperature on Total Phenolic Content and Antioxidant Capacity of Grape Seeds(Pamukkale Üniversitesi, 2015) Konuk, Dilara; Korel, FigenGrape seed, which is an organic waste arise from production of wine, juice and molasses, is considered as a functional food ingredient in food formulations because of its rich content of bioactive compounds. This study was performed in order to evaluate the effect of air-drying temperature on the bioactive compounds of grape seeds. In the study, total phenolic content and antioxidant activity of grape seeds that are dehydrated at different drying temperatures (40, 50 and 60 degrees C) were determined. When comparing the fresh grape seeds with the corresponding dehydrated samples, it was shown that the drying operation led to reduction of total phenolic contents and the total phenolic contents decreased with an increase of the drying temperature. According to ABTS radical scavenging method, Trolox Equivalent Antioxidant Capacity (TEAC) was found to be highest for fresh grape seeds and presented lower values for grape seeds dried at three different temperatures. As a result of the study, it was demonstrated that grape seed is a powerful antioxidant source and it has still high antioxidant activity after drying process. However, drying at low temperatures was put forward to be advantageous in order to reduce the losses of phenolic components.Article Object Detection With Brief Descriptors and Locality Sensitive Matching for Augmented Reality(Pamukkale Üniversitesi, 2017) Özuysal, MustafaIn this paper, an object detection approach suitable for mobile augmented reality is presented. The baseline approach is bused on matching keypoint descriptors and yerin.,ing these matches with geometric constraints. The performance optimizations necessary for speeding up matching are detailed. It is [ifs demonstrated that it is possible to increase the performance of the Locality Sensitive Hashing by exploiting approaches from the information retrieval field.Article Phase Noise Compensation in Frequency Modulated Continuous Wave (fmcw) Measurement Systems(Gazi Üniversitesi, 2018) Vardarlı, Eren; Yüksel Aldoğan, KıvılcımWe present the analysis of the phase noise compensation algorithms used in Frequency Modulated Continuous Wave measurement systems taking into account all the design parameters. This allows obtaining a generic yet realistic framework for the FMCW-based systems ranging from RF to optical frequencies. The efficiency of the proposed phase-noise compensation algorithm has been verified by the way of simulations. The simulation results show a good agreement with the mathematical foundations discussed in the paper. This work could have a technological implication in many fields (e.g. SAR radar, optical fiber sensor interrogation) in such a way that the stringent and expensive hardware requirements due to nonlinear frequency modulation effects can be overcome a posteriori by the phase noise compensation algorithm demonstrated in this article.Conference Object Consistency Analysis of Kalman Filter for Modal Analysis of Structures(Institute of Electrical and Electronics Engineers Inc., 2009) Tanyer, İlker; Özen, Serdar; Dönmez, Cemalettin; Altınkaya, Mustafa AzizIn this paper, Consistency Analysis of Kalman Filter for Modal Analysis of Structural Systems is made. As a future work, A fundamental Modal Analysis algorithm, Eigensystem Realization Algorithm(ERA) will be used with Kalman filters together to make a modal parameter estimation for a structural system. By applying ERA to the impulse response measurements taken from the structure, a state-space representation will be written. Kalman filter will be used as a state estimator in this study and it will have a critical role on minimizing the measurement noise. Before using Kalman filter with ERA, a consistency analysis of Kalman filter is made for artificial impulse response data of the structural system.Conference Object A Study on Nonlinear Photonic Crystal Optical Switching With Chi((3)) Type Material(Institute of Electrical and Electronics Engineers Inc., 2009) Karakılınç, Özgür Önder; Dinleyici, Mehmet SalihIn this study two dimensional square photonic crystal with line defect waveguide and embedded in nonlinear Kerr type dielectric rods are examined. Depending on the number and location of Kerr type nonlinear rods, power flux and harmonics are investigated. Optical switching of carrier signal is performed with using the control signal.Conference Object Alpha-Trimmed Means of Multiple Location Estimates(Institute of Electrical and Electronics Engineers Inc., 2013) Altınkaya, Mustafa AzizLocalization by distance measurements is a common technique for solving this contemporary problem. The methods which achieve the theoretically optimum solutions have generally iterative structures. That is why when limited computational load is required, suboptimum methods described by closed form formulas like the one of Coope which depends on orthogonal decomposition of sensor coordinates, are preferred. In this method, when there are more than necessary distance measurements required for localization, the location will be found as the arithmetic average of the estimates obtained using the all three-combinations of distance measurements. In the averaging, eliminating the outlier estimates will increase the performance. In this case discarding the estimates making the ratio of alpha which are farthest away from the arithmetic average, one attains the socalled alpha-trimmed mean of the estimates. Applying this technique, the disturbing effects of impulsive mixture of Gaussian contamination are eliminated and similar performances as in the case of Gaussian distance measurements are attained in localization.Conference Object Quasi-Supervised Learning on Dna Regions in Colon Cancer Histology Slides(Institute of Electrical and Electronics Engineers Inc., 2013) Köktürk, Başak Esin; Karaçalı, BilgeThe aim of this study, nuclei base automatic detection of cancerous regions via determination of DNA-rich regions in high definition histology images. In the study; DNA-rich regions were determined using k-means clustering and some mathematical morphology operations, the diseased regions were diagnosed using morphological characteristics via quasi-supervised learning. It's observed that quasi-supervised learning method successfully separates cancerous chromatin regions from others successfully with experiments of colon cross-section histology images.Conference Object A Bayesian Approach for Licence Plate Recognition Developed on a Realistic Simulation Environment(Institute of Electrical and Electronics Engineers Inc., 2013) Efeler, Mahmut Cenk; Altınkaya, Mustafa Aziz; Gümüştekin, ŞevketTemplate matching is one of the most common methods for license plate recognition. This method discards prior probabilities of license plate codes. The posterior code class probabilities constructed by including the prior probability information are expected to improve the recognition performance. The probability information that needs to be included requires extensive training data, which is quite costly to obtain. In order to generate these training images a license plate image simulator is developed with a realistic noise model. Simulated license plate images are then used to test a Bayesian decision theory based recognition procedure. Test results indicate that, with the inclusion of prior information, significant recognition gain is obtained with respect to standard template matching method at high noise levels.