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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only Performance measures for video object segmentation and tracking(IEEE-Inst Electrical Electronics Engineers Inc, 2004) Erdem, Çiğdem Eroğlu; Sankur, Bülent; Department of Electrical and Electronics Engineering; Tekalp, Ahmet Murat; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 26207We propose measures to evaluate quantitatively the performance of video object segmentation and tracking methods without ground-truth (GT) segmentation maps. The proposed measures are based on spatial differences of color and motion along the boundary of the estimated video object plane and temporal differences between the color histogram of the current object plane and its predecessors. They can be used to localize (spatially and/or temporally) regions where segmentation results are good or bad; and/or they can be combined to yield a single numerical measure to indicate the goodness of the boundary segmentation and tracking results over a sequence. The validity of the proposed performance measures without GT have been demonstrated by canonical correlation analysis with another set of measures with GT on a set of sequences (where GT information is available). Experimental results are presented to evaluate the segmentation maps obtained from various sequences using different segmentation approaches.Publication Metadata only Motion of single terrylene molecules in confined channels of poly(butadiene)-poly(ethylene oxide) diblock copolymer(Amer Chemical Soc, 2009) N/A; Department of Physics; Department of Chemistry; Yorulmaz, Mustafa; Kiraz, Alper; Demirel, Adem Levent; Master Student; Faculty Member; Faculty Member; Department of Physics; Department of Chemistry; Graduate School of Sciences and Engineering; College of Sciences; College of Sciences; N/A; 22542; 6568The motion of terrylene probe molecules in confined PB channels of an asymmetric PB-PEO diblock copolymer has been investigated by single molecule tracking. The one-dimensional diffusion coefficients were found to be significantly smaller and had a narrower distribution compared to two-dimensional diffusion coefficients in PB. The trajectories of some single molecules showed unusual behavior of directed motion where mean square displacement had a parabolic dependence oil lag time. The likely origin of this behavior is discussed in terms of local variations in the PB channel width and the resulting change in the local density. The results show the effect of nonuniformities and heterogeneities in the channels on the motion of single molecules and demonstrate the sensitivity of single molecule tracking in characterizing self-assembled block copolymer morphologies.Publication Metadata only High-resolution beam steering using microlens arrays(Optical Soc Amer, 2006) N/A; N/A; Department of Electrical and Electronics Engineering; Akatay, Ata; Ataman, Çağlar; Ürey, Hakan; 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; 8579Imaging or beam-steering systems employing a periodic array of microlenses or micromirrors suffer from diffraction problems resulting from the destructive interference of the beam segments produced by the array. Simple formulas are derived for beam steering with segmented apertures that do not suffer from diffraction problems because of the introduction of a moving linear phase shifter such as a prescan lens before the periodic structure. The technique substantially increases the resolution of imaging systems that employ microlens arrays or micromirror arrays. Theoretical, numerical, and experimental results demonstrating the high-resolution imaging concept using microlens arrays are presented.Publication Metadata only Classification of cytochrome P450 inhibitors with respect to binding free energy and pIC50 using common molecular descriptors(Amer Chemical Soc, 2009) N/A; Department of Chemical and Biological Engineering; Department of Industrial Engineering; Dağlıyan, Onur; Kavaklı, İbrahim Halil; Türkay, Metin; Master Student; Faculty Member; Faculty Member; Department of Chemical and Biological Engineering; Department of Industrial Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; 40319; 24956Virtual screening of chemical libraries following experimental assays of drug candidates is a common procedure in structure based drug discovery. However, the relationship between binding free energies and biological activities (pIC(50)) of drug candidates is sfill an unsolved issue that limits the efficiency and speed of drug development processes. In this study, the relationship between them is investigated based on a common molecular descriptor set for human cytochrome P450 enzymes (CYPs). CYPs play an important role in drug-drug interactions, drug metabolism, and toxicity. Therefore, in silico prediction of CYP inhibition by drug candidates is one of the major considerations in drug discovery. The combination of partial leastsquares regression (PLSR) and a variety of classification algorithms were employed by considering this relationship as a classification problem. Our results indicate that PLSR with classification is a powerful tool to predict more than one output such as binding free energy and pIC(50) simultaneously. PLSR with mixedinteger linear programming based hyperboxes predicts the binding free energy and pIC(50) with a mean accuracy of 87.18% (min: 81.67% max: 97.05%) and 88.09% (min: 79.83% max: 92.90%), respectively, for the cytochrome p450 superfamily using the common 6 molecular descriptors with a 10-fold cross- val idati on.Publication Metadata only Embedding and retrieving private metadata in electrocardiograms(Springer, 2009) Vlachos, Michail; Lucchese, Claudio; Van Herle, Helga; Yu, Philip S; Department of Electrical and Electronics Engineering; Kozat, Süleyman Serdar; Faculty Member; Department of Electrical and Electronics Engineering; College of Engineering; 177972Due to the recent explosion of 'identity theft' cases, the safeguarding of private data has been the focus of many scientific efforts. Medical data contain a number of sensitive attributes, whose access the rightful owner would ideally like to disclose only to authorized personnel. One way of providing limited access to sensitive data is through means of encryption. In this work we follow a different path, by proposing the fusion of the sensitive metadata within the medical data. Our work is focused on medical time-series signals and in particular on Electrocardiograms (ECG). We present techniques that allow the embedding and retrieval of sensitive numerical data, such as the patient's social security number or birth date, within the medical signal. The proposed technique not only allows the effective hiding of the sensitive metadata within the signal itself, but it additionally provides a way of authenticating the data ownership or providing assurances about the origin of the data. Our methodology builds upon watermarking notions, and presents the following desirable characteristics: (a) it does not distort important ECG characteristics, which are essential for proper medical diagnosis, (b) it allows not only the embedding but also the efficient retrieval of the embedded data, (c) it provides resilience and fault tolerance by employing multistage watermarks (both robust and fragile). Our experiments on real ECG data indicate the viability of the proposed scheme.Publication Metadata only Assessing the universal structure of personality in early adolescence: the NEO-PI-R and NEO-PI-3 in 24 cultures(SAGE, 2009) De Fruyt, Filip; de Bolle, Marleen; McCrae, Robert R.; Terracciano, Antonio; Costa Jr., Paul T.; Aguilar-Vafaie, Maria E.; Ahn, Chang-Kyu; Ahn, Hyun-Nie; Alcalay, Lidia; Allik, Jüri; Avdeyeva, Tatyana; Blatný, Marek; Bratko, Denis; Brunner-Sciarra, Marina; Cain, Thomas R.; Chittcharat, Niyada; Crawford, Jarret T.; Ficková, Emília; de Figueroa, Nora Leibovich; Lima, Margarida P.; Martin, Thomas A.; Reátegui, Norma; Siuta, Jerzy; Department of Psychology; Gülgöz, Sami; Faculty Member; Department of Psychology; College of Social Sciences and Humanities; 49200The structure and psychometric characteristics of the NEO Personality Inventory-3 (NEO-PI-3), a more readable version of the Revised NEO Personality Inventory (NEO-PI-R), are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 years from 24 cultures. Replacement items in the PI-3 showed on average stronger item-total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. The authors discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan. © 2009 Sage Publications.Publication Metadata only Formation of polyamide nanofibers by directional crystallization in aqueous solution(Wiley-V C H Verlag Gmbh, 2007) Department of Chemistry; Demirel, Adem Levent; Faculty Member; Department of Chemistry; College of Sciences; 6568N/APublication Metadata only Pi-stack dimers of small polyaromatic hydrocarbons: a path to the packing of graphenes(Amer Chemical Soc, 2009) Department of Chemistry; Yurtsever, İsmail Ersin; Faculty Member; Department of Chemistry; College of Sciences; 7129MP2 calculations of the stacking energy are reported for the dimers of a set of polycyclic aromatic hydrocarbons. The interaction strengths and their dependence on the shape-dependent measures as well as the aromatic character of the monomer are studied. For small systems involving four to six rings, the noncovalent interactions seem to be independent of the shape of the monomers. The most preferred conformations for parallel stacked dimers are not aligned exactly but off-center with small shifts; however, these shifts are on the order of 1 angstrom, and the energy necessary to keep them aligned is less than 0.5 kcal/mol per ring. Small-angle rotations within the molecular planes also do not require much energy, and in some cases they lead to stronger interactions.Publication Metadata only Complementary and alternative medicine use in colorectal cancer patients in seven European countries(Churchill Livingstone, 2005) Molassiotis, A; Fernandez-Ortega, P; Pud, D; Ozden, G; Hummerston, S; Scott, JA; Panteli, V; Gudmundsdottir, G; Selvekerova, S; Patiraki, E; Kearney, N; N/A; Platin, Nurgün; Faculty Member; School of Nursing; 191329Purpose: The aim of the present study was to examine the use of complementary and alternative medicine (CAM) in a sample of colorectal cancer patients in Europe. Methods: The study was a descriptive cross-sectional survey and data were collected through a 27-item self-reported questionnaire from seven European countries. Results: As part of a Larger study, 126 colorectal cancer patients participated in this survey. Among the participants, 32% used CAM after the diagnosis of cancer. Almost half the CAM therapies used were new therapies, never tried before the diagnosis. The most common CAM therapies included herbal medicine (48.7%), homeopathy (20.5%), use of vitamins/minerals (17.9%), spiritual therapies (15.4%), medicinal teas (15.4%) and relaxation techniques (12.8%). A dramatic increase was observed in the use of CAM from usage levels before the cancer diagnosis. High levels of satisfaction with CAM were also reported. Patients used CAM more often to increase the body's ability to fight the cancer or to improve physical welt-being. However, expectations did not always match with the benefits reported. Conclusions: As one-third of colorectal cancer patients use CAM, health professionals should be more aware of this approach to the patient's management. They should discuss the role of CAM therapies with their patients in a non-judgemental and open manner, and endeavour to provide accurate information in order to allow patients to make their own decision about CAM.Publication Metadata only Determination of the stimulated emission cross section from laser-induced pump saturation data in Cr4+-doped solid-state lasers(Optical Soc america, 2001) Department of Physics; Department of Physics; Sennaroğlu, Alphan; Yaman, Fatih; Faculty Member; Undergraduate Student; Department of Physics; College of Sciences; College of Sciences; 23851; N/AWe describe a novel method for the determination of the stimulated emission cross section in Cr4+-doped solid-state lasers from laser-induced pump saturation data. the technique uses the fact that increasing intra-cavity laser intensity stimulates a faster decay of excited atoms and reduces the saturation of pump absorption. a numerical model was developed to analyze the experimental data collected from Cr4+:YaG and Cr4+:forsterite lasers. the best-fit values of the stimulated emission cross section agree with previous results. To demonstrate the applicability of the method to other solid-state lasers, the same technique was also used to determine the emission cross section in a Cr2+:ZnSe laser.