Browsing by Author "Yavuz, Yasemin"

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    Comparison of mandibular index values determined from standard panoramic versus cone beam computed tomography reconstructed images
    (2019) Secgin, Cansu Koseoglu; Gulsahi, Ayse; Yavuz, Yasemin; Kamburoglu, Kivanc; 30497908
    Objective. The aim of this study was to compare mandibular index values, including the mandibular cortical index (MCI), mental index (MI), and panoramic mandibular index (PMI), determined on the basis of cone beam computed tomography (CBCT) and panoramic reconstructed (PR) images. Study Design. PR and CBCT images of 182 patients were retrospectively analyzed. Cross-sectional (CS) and PR images were obtained from CBCT data. The MCI, MI, and PMI were assessed on CS, PR, and panoramic images and evaluated for intra- and interobserver agreements by kappa-value or intraclass correlation coefficient (ICC) analysis. Agreement among measurement methods was assessed by using the Bland-Altman method, with CS images as the gold standard for linear measurements. Results. Measurements from PR and CS images agreed with those from panoramic images in 66.7% and 53.8% of C3 classifications of MCI (porous cortices forming many endosteal residues), respectively. Panoramic and CBCT images exhibited good agreement in MI findings (ICC 0.91) and moderate (PR and panoramic images: ICC 0.79) to good (CS and panoramic images: ICC 0.87) agreement in PMI findings. Conclusions. Because of the overlapping of buccal and lingual cortices, panoramic images are especially inadequate for determining the C3 category of MCI. However, CS images obtained from available CBCT data provide better visibility compared with panoramic images and, therefore, can be used for evaluating mandibular indices.
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    SECOND-ORDER RESPONSE SURFACE METHOD: FACTORIAL EXPERIMENTS AN ALTERNATIVE METHOD IN THE FIELD OF AGRONOMY
    (2014) Tekindal, Mustafa Agah; Bayrak, Hulya; Ozkaya, Berrin; Yavuz, Yasemin
    The main purpose in all experimental designs is to take into account the factors that are considered likely to have an effect on the response variable emphasized, and to minimize the error of experiment in this way. Bread, which is the staple human food, cannot have any negative effect on human beings as long as it is produced by using suitable materials under appropriate conditions. However, when inappropriate amounts of raw materials are used (e.g. non-optimal amounts of bran, yeast or other additives), bread threatens health. In this study, Box-BehnkenDesign (BBD) and Central Composite Design (CCD), the two different designs of the response surface method, were applied to a single dataset. Two designs were evaluated in terms of the results obtained. The purpose in the second-order factorial experiments is to identify the optimum levels of independent variables for the dependent variable. In this study, the implementation of second-order response surface model and interpretation of the results were based on 2(k) CCD (Central Composite Design) and BBD (Box-Behnken Design) with one replicate. In the CCD, the amount of bran added, flour type, the ratio of yeast added, furnace temperature, the duration of remaining in the furnace, and fermentation time were accepted to be significant factors that affected volume yield. In addition, R-2 = 80.7% shows that the regression equation explains variables by 80.7%. In the BBD, the ratio of bran added, the type of flour, the ratio of yeast added, furnace temperature (only in quadratic form), the duration of remaining in the furnace (only in quadratic form), and fermentation time (only in quadratic form) were accepted to be significant factors that affected volume yield. Furthermore, R-2 = 89.64% shows that the regression equation explains variables by %89.64. This method provides savings in terms of time and the amount of material by limiting the area at particular levels. Researcher may use the results of either CCD or BBD (whichever s/he deems suitable) according to the volume s/he wants to obtain.