Optical and other property changes of M-50 bearing steel surfaces for different lubricants and additive prior to scuffing

An ester lubricant base oil containing one or more standard additives to protect against wear, corrosion, and oxidation was used in an experimental ball/plate elastohydrodynamic contact under load and speed conditions such as to induce scuffing failure in short times. Both the ball and the plate were of identically treated M-50 steel. After various periods of operating time the wear track on the plate was examined with an interference microscope of plus or minus 30 A depth resolution and sometimes also with a scanning ellipsometer and an Auger spectrometer. The optically deduced surface profiles varied with wavelength, indicating the presence of surface coatings, which were confirmed by the other instruments. As scuffing was approached, a thin (approximately A) oxide layer and a carbide layer formed in the wear track in particular when tricresylphosphate antiwear additive was present in the lubricant. The rates of the formation of these layers and their reactivity toward dilute alcholic HCl depended strongly on the lubricant and additives. Based on these results suggestions for improved formulations and a test method for bearing reliability could be proposed

Audio source separation for music in low-latency and high-latency scenarios

Aquesta tesi proposa mètodes per tractar les limitacions de les tècniques existents de separació de fonts musicals en condicions de baixa i alta latència. En primer lloc, ens centrem en els mètodes amb un baix cost computacional i baixa latència. Proposem l'ús de la regularització de Tikhonov com a mètode de descomposició de l'espectre en el context de baixa latència. El comparem amb les tècniques existents en tasques d'estimació i seguiment dels tons, que són passos crucials en molts mètodes de separació. A continuació utilitzem i avaluem el mètode de descomposició de l'espectre en tasques de separació de veu cantada, baix i percussió. En segon lloc, proposem diversos mètodes d'alta latència que milloren la separació de la veu cantada, gràcies al modelatge de components específics, com la respiració i les consonants. Finalment, explorem l'ús de correlacions temporals i anotacions manuals per millorar la separació dels instruments de percussió i dels senyals musicals polifònics complexes.Esta tesis propone métodos para tratar las limitaciones de las técnicas existentes de separación de fuentes musicales en condiciones de baja y alta latencia. En primer lugar, nos centramos en los métodos con un bajo coste computacional y baja latencia. Proponemos el uso de la regularización de Tikhonov como método de descomposición del espectro en el contexto de baja latencia. Lo comparamos con las técnicas existentes en tareas de estimación y seguimiento de los tonos, que son pasos cruciales en muchos métodos de separación. A continuación utilizamos y evaluamos el método de descomposición del espectro en tareas de separación de voz cantada, bajo y percusión. En segundo lugar, proponemos varios métodos de alta latencia que mejoran la separación de la voz cantada, gracias al modelado de componentes que a menudo no se toman en cuenta, como la respiración y las consonantes. Finalmente, exploramos el uso de correlaciones temporales y anotaciones manuales para mejorar la separación de los instrumentos de percusión y señales musicales polifónicas complejas.This thesis proposes specific methods to address the limitations of current music source separation methods in low-latency and high-latency scenarios. First, we focus on methods with low computational cost and low latency. We propose the use of Tikhonov regularization as a method for spectrum decomposition in the low-latency context. We compare it to existing techniques in pitch estimation and tracking tasks, crucial steps in many separation methods. We then use the proposed spectrum decomposition method in low-latency separation tasks targeting singing voice, bass and drums. Second, we propose several high-latency methods that improve the separation of singing voice by modeling components that are often not accounted for, such as breathiness and consonants. Finally, we explore using temporal correlations and human annotations to enhance the separation of drums and complex polyphonic music signals

African American Male Achievement Initiative: A Closer Look At Attendance Of African American Males In OUSD

This report examines data, best practices, and policies related to attendance and chronic absence and offers recommendations for reducing the levels of chromic absence for African American males in Oakland Unified School District (OUSD). It analyzes one year of attendance data (2010-2011) for African American males in OUSD, looking at chronic absence by grade level, types of absence, and reasons given for absence, as well as comparing rates of chronic absence to other males groups in OUSD

African American Male Achievement Initiative: A Deeper Look At African American Males In OUSD

This report provides further insights into the status of African American boys in Oakland Unified School Distric (OUSD) and aims to reverse the academic and social inequities they face in seven key areas: the achievement gap, graduation rates, literacy, suspensions, attendance, middle school holding power, and juvenile detention. A framework of three levels of well-being (on course, at risk of falling off course, and off course) was used to understand how African American male students are faring in these areas

The effects of online content structure on attention & memory: exploring optimal structure for news on corporate web sites

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file viewed on (December 14, 2006)Includes bibliographical references.Vita.Thesis (M.A.) University of Missouri-Columbia 2005.Dissertations, Academic -- University of Missouri--Columbia -- Journalism.This study examined the effects of online content structure on attention and memory as indicators to overall communication effectiveness. For the purposes of this study, content structure was defined as either Bite-Snack-Meal (BSM), which involved presentation of information through several clickable hyperlinks, or traditional, inverted pyramid news writing without hyperlinks. The design was a mixed 2 (content structure) x 6 (article) repeated measures design. Heart rate was collected during a 10 second baseline period and during stimulus exposure. A multiple choice recognition test and a short answer cued recall test were utilized to measure memory. Attention and encoding were tested by submitting the data to a repeated measures ANOVA. Findings suggest that content structure does impact allocation of cognitive resources for controlled attention. BSM requires less effort and fewer cognitive resources allocated during exposure with no significant memory differences