382 research outputs found

    The effect of training of information processing approach on self-confidence in girl students in vocational schools in Isfahan, Iran

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    BACKGROUND: Self-confidence is one of the main aspects of mental health during adolescence, which is essential for achieving goals. The purpose of this study is to investigate the effectiveness of training information processing approach on self-confidence in female students of vocational schools in Isfahan, Iran.METHODS: This randomized control trial study was conducted on 50 adolescent female students in Isfahan in academic year 2016-2017. The Eysenck self-esteem scale (ESES) was used to assess self-esteem among the students. Training the information processing approach was performed on the experimental group. Data were analyzed by SPSS software using paired sample t-test, independent t- test, and Kolmogorov-Smirnov (K-S) test.RESULTS: The scores of the students’ self-confidence in the experimental group increased compared to the control group (P ≀ 0.050).CONCLUSION: According to the results of this study, training information processing approach is effective on self-confidence in female students of vocational schools in Isfahan. It is suggested to consider the training information processing approach along with other approaches

    Advanced maximum entropy approaches for medical and microscopy imaging

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    The maximum entropy framework is a cornerstone of statistical inference, which is employed at a growing rate for constructing models capable of describing and predicting biological systems, particularly complex ones, from empirical datasets.‎ In these high-yield applications, determining exact probability distribution functions with only minimal information about data characteristics and without utilizing human subjectivity is of particular interest. In this thesis, an automated procedure of this kind for univariate and bivariate data is employed to reach this objective through combining the maximum entropy method with an appropriate optimization method. The only necessary characteristics of random variables are their continuousness and ability to be approximated as independent and identically distributed. In this work, we try to concisely present two numerical probabilistic algorithms and apply them to estimate the univariate and bivariate models of the available data. In the first case, a combination of the maximum entropy method, Newton's method, and the Bayesian maximum a posteriori approach leads to the estimation of the kinetic parameters with arterial input functions (AIFs) in cases without any measurement of the AIF. ‎The results shows that the AIF can reliably be determined from the data of dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) by maximum entropy method. Then, kinetic parameters can be obtained. By using the developed method, a good data fitting and thus a more accurate prediction of the kinetic parameters are achieved, which, in turn, leads to a more reliable application of DCE-MRI. ‎ In the bivariate case, we consider colocalization as a quantitative analysis in fluorescence microscopy imaging. The method proposed in this case is obtained by combining the Maximum Entropy Method (MEM) and a Gaussian Copula, which we call the Maximum Entropy Copula (MEC). This novel method is capable of measuring the spatial and nonlinear correlation of signals to obtain the colocalization of markers in fluorescence microscopy images. Based on the results, MEC is able to specify co- and anti-colocalization even in high-background situations.‎ ‎The main point here is that determining the joint distribution via its marginals is an important inverse problem which has one possible unique solution in case of choosing an proper copula according to Sklar's theorem. This developed combination of Gaussian copula and the univariate maximum entropy marginal distribution enables the determination of a unique bivariate distribution. Therefore, a colocalization parameter can be obtained via Kendall’s t, which is commonly employed in the copula literature. In general, the importance of applying these algorithms to biological data is attributed to the higher accuracy, faster computing rate, and lower cost of solutions in comparison to those of others. The extensive application and success of these algorithms in various contexts depend on their conceptual plainness and mathematical validity. ‎ Afterward, a probability density is estimated via enhancing trial cumulative distribution functions iteratively, in which more appropriate estimations are quantified using a scoring function that recognizes irregular fluctuations. This criterion resists under and over fitting data as an alternative to employing the Bayesian criterion. Uncertainty induced by statistical fluctuations in random samples is reflected by multiple estimates for the probability density. In addition, as a useful diagnostic for visualizing the quality of the estimated probability densities, scaled quantile residual plots are introduced. Kullback--Leibler divergence is an appropriate measure to indicate the convergence of estimations for the probability density function (PDF) to the actual PDF as sample. The findings indicate the general applicability of this method to high-yield statistical inference.Die Methode der maximalen Entropie ist ein wichtiger Bestandteil der statistischen Inferenz, die in immer stĂ€rkerem Maße fĂŒr die Konstruktion von Modellen verwendet wird, die biologische Systeme, insbesondere komplexe Systeme, aus empirischen DatensĂ€tzen beschreiben und vorhersagen können. In diesen ertragreichen Anwendungen ist es von besonderem Interesse, exakte Verteilungsfunktionen mit minimaler Information ĂŒber die Eigenschaften der Daten und ohne Ausnutzung menschlicher SubjektivitĂ€t zu bestimmen. In dieser Arbeit wird durch eine Kombination der Maximum-Entropie-Methode mit geeigneten Optimierungsverfahren ein automatisiertes Verfahren verwendet, um dieses Ziel fĂŒr univariate und bivariate Daten zu erreichen. Notwendige Eigenschaften von Zufallsvariablen sind lediglich ihre Stetigkeit und ihre Approximierbarkeit als unabhĂ€ngige und identisch verteilte Variablen. In dieser Arbeit versuchen wir, zwei numerische probabilistische Algorithmen prĂ€zise zu prĂ€sentieren und sie zur SchĂ€tzung der univariaten und bivariaten Modelle der zur VerfĂŒgung stehenden Daten anzuwenden. ZunĂ€chst wird mit einer Kombination aus der Maximum-Entropie Methode, der Newton-Methode und dem Bayes'schen Maximum-A-Posteriori-Ansatz die SchĂ€tzung der kinetischen Parameter mit arteriellen Eingangsfunktionen (AIFs) in FĂ€llen ohne Messung der AIF ermöglicht. Die Ergebnisse zeigen, dass die AIF aus den Daten der dynamischen kontrastverstĂ€rkten Magnetresonanztomographie (DCE-MRT) mit der Maximum-Entropie-Methode zuverlĂ€ssig bestimmt werden kann. Anschließend können die kinetischen Parameter gewonnen werden. Durch die Anwendung der entwickelten Methode wird eine gute Datenanpassung und damit eine genauere Vorhersage der kinetischen Parameter erreicht, was wiederum zu einer zuverlĂ€ssigeren Anwendung der DCE-MRT fĂŒhrt. Im bivariaten Fall betrachten wir die Kolokalisierung zur quantitativen Analyse in der Fluoreszenzmikroskopie-Bildgebung. Die in diesem Fall vorgeschlagene Methode ergibt sich aus der Kombination der Maximum-Entropie-Methode (MEM) und einer Gaußschen Copula, die wir Maximum-Entropie-Copula (MEC) nennen. Mit dieser neuartigen Methode kann die rĂ€umliche und nichtlineare Korrelation von Signalen gemessen werden, um die Kolokalisierung von Markern in Bildern der Fluoreszenzmikroskopie zu erhalten. Das Ergebnis zeigt, dass MEC in der Lage ist, die Ko- und Antikolokalisation auch in Situationen mit hohem Grundrauschen zu bestimmen. Der wesentliche Punkt hierbei ist, dass die Bestimmung der gemeinsamen Verteilung ĂŒber ihre Marginale ein entscheidendes inverses Problem ist, das eine mögliche eindeutige Lösung im Falle der Wahl einer geeigneten Copula gemĂ€ĂŸ dem Satz von Sklar hat. Diese neu entwickelte Kombination aus Gaußscher Kopula und der univariaten Maximum Entropie Randverteilung ermöglicht die Bestimmung einer eindeutigen bivariaten Verteilung. Daher kann ein Kolokalisationsparameter ĂŒber Kendall's t ermittelt werden, der ĂŒblicherweise in der Copula-Literatur verwendet wird. Die Bedeutung der Anwendung dieser Algorithmen auf biologische Daten lĂ€sst sich im Allgemeinen mit hoher Genauigkeit, schnellerer Rechengesch windigkeit und geringeren Kosten im Vergleich zu anderen Lösungen begrĂŒnden. Die umfassende Anwendung und der Erfolg dieser Algorithmen in verschiedenen Kontexten hĂ€ngen von ihrer konzeptionellen Eindeutigkeit und mathematischen GĂŒltigkeit ab. Anschließend wird eine Wahrscheinlichkeitsdichte durch iterative Erweiterung von kumulativen Verteilungsfunktionen geschĂ€tzt, wobei die geeignetsten SchĂ€tzungen mit einer Scoring-Funktion quantifiziert werden, um unregelmĂ€ĂŸige Schwankungen zu erkennen. Dieses Kriterium verhindert eine Unter- oder Überanpassung der Daten als Alternative zur Verwendung des Bayes-Kriteriums. Die durch statistische Schwankungen in Stichproben induzierte Unsicherheit wird durch mehrfache SchĂ€tzungen fĂŒr die Wahrscheinlichkeitsdichte berĂŒcksichtigt. ZusĂ€tzlich werden als nĂŒtzliche Diagnostik zur Visualisierung der QualitĂ€t der geschĂ€tzten Wahrscheinlichkeitsdichten skalierte Quantil-Residuen-Diagramme eingefĂŒhrt. Die Kullback-Leibler-Divergenz ist ein geeignetes Maß, um die Konvergenz der SchĂ€tzungen fĂŒr die Wahrscheinlichkeitsdichtefunktion (PDF) zu der tatsĂ€chlichen PDF als Stichprobe anzuzeigen. Die Ergebnisse zeigen die generelle Anwendbarkeit dieser Methode fĂŒr statistische Inferenz mit hohem Ertrag.

    Doctor of Philosophy

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    dissertationExpanded Polystyrene (EPS) geofoam has become a preferred material in various construction applications due to its light weight. Application of EPS accelerates the projects particularly on soft soils. The focus of this research is on the application of the EPS in embankments and its behavior mainly under harmonic vibration. The goal of this study was to investigate dynamic characteristics of freestanding vertical EPS geofoam embankment and address potential seismic issues that result from the distinguished dynamic behavior of such systems due to the layered and discrete block structure. A series of experimental studies on EPS 19 and a commercially available adhesive was conducted. Two-dimensional numerical analyses were performed to replicate the response of EPS geofoam embankment to horizontal and vertical harmonic motions. The results of the analyses have shown that for some acceleration amplitude levels interlayer sliding is expected to occur in EPS geofoam embankments almost immediately after the start of the base excitation; however, as a highly efficient energy dissipation mechanism sliding ceases rapidly. Shear keys and adhesive may be used to prevent interlayer sliding if they cover the proper extent of area of the embankment. EPS blocks placed in the corners of the embankment and at the edges of the segment prohibited from sliding may experience high stress concentrations. The embankment may show horizontal sway and rocking once sliding is prevented

    Investigating the relationship between the institutional ownership and conservative elements in Tehran Stock Exchange

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    The institutional ownership has been one of the most important elements of capital markets worldwide so that most of these investments are done by this organization. This research investigated the effect of institutional ownership on the conservative elements in Tehran Stock Exchange. The Hypotheses of this research were developed by using the conservative theories of Basu (e.g. Basu , 1997) and the models presented by Lara et al (e.g. Lara et al., 2007). Using the data of financial statements and stock prices of 115 companies approved in Tehran Stock Exchange during 2008 to 2013 and multivariate linear regression analysis, the results showed that the institutional ownership of companies does not affect the conservative elements

    Investigating the relationship between the institutional ownership and conservative elements in Tehran Stock Exchange

    Get PDF
    The institutional ownership has been one of the most important elements of capital markets worldwide so that most of these investments are done by this organization. This research investigated the effect of institutional ownership on the conservative elements in Tehran Stock Exchange. The Hypotheses of this research were developed by using the conservative theories of Basu (e.g. Basu , 1997) and the models presented by Lara et al (e.g. Lara et al., 2007). Using the data of financial statements and stock prices of 115 companies approved in Tehran Stock Exchange during 2008 to 2013 and multivariate linear regression analysis, the results showed that the institutional ownership of companies does not affect the conservative elements
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