1,728,380 research outputs found
Atmosphaerische CS_2-Oxidation: Kinetik und Mechanismen
No full textDissertation submitted by Yuhui SuCopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Maximally selected test statistics: methodology and application
No full textIn clinical or public health research studies, an investigator often assumes that some continuous predictive variable X allows classifying study population into a risk and a normal group with respect to a response variable Y. The aim of these research efforts is to transform a continuous variable into a binary variable by identifying a threshold or cutpoint in the predictor to distinguish different groups with high or low probabilities of favorable outcomes. Several methods including maximally selected chi-square statistics, maximally selected rank statistics and Koziol’s exact finite sample distribution approach to search for the optimal cut point have been reviewed and compared in Chapter 1. Since utilizing the maximally selected rank statistic to analyze semi-continuous predictors has not been discussed in the literatures, this dissertation provides the comparison of the null distribution, power curve, precision of cut point estimation between semi-continuous and continuous predictive variables via simulation. In Chapter 2, we confirmed the critical values to reject the null hypotheses are lower in semi-continuous predictors compare to continuous predictors. In Chapter 3, we show the power of maximally selected rank statistic from the semi-continuous predictor is stochastically larger than that from the continuous predictor. In Chapter 4, we found besides the sample size and effect size, the location of the true cut-point also affects the precision of the cut-point estimates. Compared to the continuous predictor, the semi-continuous predictor has higher percentage of correct cut-point estimates. The null distributions for semi-continuous predictor simulated in Chapter 1 are then applied to the study of “lead exposure, HPA dysfunction, blood pressure and hypertension risk” (Fiedler 2010) in Chapter 6 to determine the cut point in blood lead level that triggers increased stress. This application focused on the multivariate relationship between predictor variables and response variable, which were not discussed in the literature. After adjusted by other confounder variables through the regression residuals, a significant cut-point of 2 μg/dL in blood lead level is identified. Since the use of the regression residual of the response variable violates the independence assumption of this maximally selected rank statistics, this dissertation also demonstrated the robustness of this assumption in chapter 5.D.P.H.Includes bibliographical referencesby Yuhui M
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Evaluation of content-based acoustic features for musical genre classification
No full textIn this thesis, we evaluate content-based acoustic features for musical genre classification. Effectiveness of various acoustic features are compared using a k-nearest neighbor (KNN) classifier. By utilizing the combinations of acoustic features, an average classification accuracy of for GTZAN database is achieved, which is comparable to prior work. A statistical test, McNemar's test, is applied to support the idea that musical genre is intrinsically related to content-based acoustic features. Especially for some genres, we are able to identify the particular associated acoustic property. In addition, by comparing our KNN results to a psychoacoustic listening experiment, we associate various human perceptual dimensions with low-level acoustic features.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-02-28 without embargo termsThe student, Yuhui Lai, accepted the attached license on 2016-12-09 at 03:00.The student, Yuhui Lai, submitted this Thesis for approval on 2016-12-09 at 03:08.This Thesis was approved for publication on 2016-12-09 at 09:45.DSpace SAF Submission Ingestion Package generated from Vireo submission #10498 on 2017-02-28 at 15:04:18Made available in DSpace on 2017-03-01T15:49:36Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-12-0
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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