Marshall University Department of Music presents a Faculty Recital - Julio Alves

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Inflation forecasts using the tips yield curve

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and EconomicsIn this paper month-on-month inflation is forecasted using information on expected inflation by participants in financial markets as an additional regressor to a direct autoregressive method and the results are compared to those of the most commonly used univariate forecasting methods. These forecasts are then used to forecast quarterly inflation and the results are compared to those of the SPF and iterated autoregressive with fixed number of lags

Análise comparativa entre o estilo segoviano e de violonistas da segunda metade do século XX : parâmetros de expressividade em quatro gravações da obra sonatina, de Federico Moreno Torroba

O presente trabalho propõe descrever detalhadamente o estilo interpretativo de Andrés Segovia, comparando-o com três interpretações pertencentes às duas últimas décadas do século XX. Para isso, analisamos de forma sistematizada os parâmetros interpretativos de tempo, dinâmica, articulação, timbre e vibrato em quatro diferentes gravações de violonistas ao longo do século XX. Partindo do princípio de que "a música é organizada hierarquicamente em uma teia de níveis interconectados" (CLARKE, 1987, p. 211), a investigação tem como enfoque a obra Sonatina, de Federico Moreno Torroba, a qual possui características claras de estrutura fraseológica e textural no âmbito da música tonal, sendo associada à estética do Neoclassicismo por Clark & Krause. Posto isso, demonstraremos que a função do intérprete consiste, em boa medida, em manipular variados parâmetros sonoros em diferentes níveis hierárquicos, de modo a enfatizar ou atenuar certos grupos de notas. As metodologias incluem a análise comparativa através do software Sonic Visualiser para identificação de diferentes parâmetros sonoros, análise em diferentes níveis hierárquicos e análise de arco de frase. Com isso, espera-se chegar a resultados que expõem de forma mais clara os recursos interpretativos que caracterizam o estilo particular de Segovia, bem como os recursos interpretativos mais utilizados nas gravações analisadas.The present research proposes to describe in detail the interpretative style of Andres Segovia, comparing it with three interpretations from the last two decades of the twentieth century. For this, we analyze in a systematic manner the parameters of time, dynamics, articulation, timbre and vibrato in four different guitar recordings throughout the twentieth century. Assuming that "music is organized hierarchically in a network of interconnected levels" (CLARKE, 1987, p. 211), the investigation focuses on the Sonatina by Federico Moreno Torroba, which has clear characteristics of phrasing and texture in the tonal music scope, being associated by Clark & Krause with the aesthetics of Neoclassicism. Therefore, we demonstrate that the function of the performer consists, in a large way, in manipulating varied sound parameters in different hierarchical levels, in order to emphasize or mitigate certain groups of notes. The methodologies include comparative analysis through the use of the Sonic Visualiser software for the identification of different sound parameters, analysis in different hierarchical levels and phrase arch analysis. This way, it is expected to get to results that indicate more clearly the most utilized interpretative resources in the analyzed recordings

A contribution to the monitoring of ceramic surface quality using a low-cost piezoelectric transducer in the grinding operation

The grinding process is usually one of the last stages in the manufacturing process chain since it can provide superior surface finish and closer dimensional tolerances. However, due to peculiarities of the grinding process, a workpiece material is susceptible to many problems, and demands a reliable real-time monitoring system. Some grinding monitoring systems have been proposed by means of sensors. However, the literature is still scarce in terms of employing time–frequency analysis techniques during the grinding of ceramics. Thus, this paper proposes an application of a low-cost piezoelectric transducer (PZT) in the analysis of the surface quality of ceramic workpieces during the grinding process by means of the frequency–time domain technique along with the ratio of power (ROP) parameter. An integrated, high-cost, commonly-used acoustic emission (AE) sensor was employed in order to compare the results with the low-cost PZT transducer. Tests were performed using a surface grinding machine. Three depth of cut values were selected in order to represent slight, moderate, and severe grinding conditions. Signals were collected at 2 MHz. The short-time Fourier transform (STFT) was studied in order to obtain the frequency variations over time. An analysis of the ROP values was performed in order to establish a correlation with the surface roughness. The ROP values are highly desirable for setting a threshold to detect the workpiece surface quality and for implementing it into a monitoring system. The results using the PZT transducer showed a great similarity to those obtained using the AE sensor

Acoustic image-based damage identification of oxide aluminum grinding wheel during the dressing operation

Abstract Grinding is a finish process of parts that require high precision and tight dimensional tolerance, which owe high value-added. As the grinding process takes place, the cutting surface of the grinding wheel undergoes wear and then its cutting capacity is reduced. On the other hand, the dressing operation is responsible for restoring the cutting surface of the grinding wheel and, therefore, plays a key role in the grinding process. This work aims at obtaining acoustic images of the grinding wheel surface to identify its conditions during the dressing operation. Experimental tests were conducted with a single-point diamond dresser in a surface grinding machine, which was equipped with an oxide aluminum grinding wheel in which specific marks were intentionally made on its surface to simulate damages for identification. An acoustic emission sensor was fixed to the dresser holder and the signal were acquired at 5 MHz. The signal spectrum was investigated and a frequency band was carefully selected, which represented the conditions of grinding wheel surface. The root mean square values were then computed from the raw signal with and without filtering for several integration periods, and the acoustic images obtained. The results show that the proposed technique is efficient to identify the damage on the wheel surface during the dressing operation as well as its location

A New Approach For Dressing Operation Monitoring Using Voltage Signals Via Impedance-Based Structural Health Monitoring

Among the methods used in structural health monitoring (SHM), the electromechanical impedance technique (EMI), which uses piezoelectric transducers of lead zirconate titanate (PZT), stands out for its low cost. This paper presents a new approach for monitoring of the dressing operation based on structural health monitoring from the digital processing of voltage signals based on the time-domain response of a PZT transducer by EMI method. Experimental tests of the dressing process were performed by using a single-point dresser equipped with a natural diamond. The voltage signals in the time-domain were collected in different damage levels using a measurements EMI System. By using damage metrics, it was possible to qualify different damage levels that the diamond suffered during the dressing operation, observing variations from the magnitude of the signals. The dressing operation is of utmost importance for the grinding process and the dresser wear negatively affects the result of the process, which owns high added value. In this way, this work contributes with a new monitoring tool which aims ensuring a consistent dressing operation.Keywords: Manufacturing process, automation, electromechanical impedance, dressing operation

Análise de Sinais de Emissao Acústica e Estatística Counts na Detecção da Alteração Microestrutural na Retificação de Aço 1045

Grinding is a high-precision, high-value-added finishing process as it is usually the last stage of the manufacturing chain. However, unsatisfactory results may occur, mainly due to changes in the microstructure of the ground workpiece. Such changes are caused by the high temperatures involved in the process due to the grinding conditions in which the part was subjected. In this way, the main objective of this work is the monitoring of the grinding process in order to detect changes in the signal and to relate them with damage occurred in the ground workpiece. The tests were carried out on a surface grinding machine, aluminum oxide grinding wheel and ABNT 1045 steel parts. Metallography was performed on the parts for a more further analysis of their microstructure. The recording of signals was obtained at a sample rate of 2 MHz through an acoustic emission sensor (AE). A frequency study for the selection of the best frequency bands that characterize damage occurred in the ground workpiece. The event counts statistic was applied to the filtered signal in the chosen frequency bands. The results of this work show that the grinding conditions influence the signal and, therefore, its frequency spectrum.Keywords: Manufacturing process; automation, monitoring; grinding process; acoustic emission, damage detectio

Aplicação da técnica de CAMQL na retificação cilíndrica externa do aço AISI 4340 utilizando rebolo de CBN

O processo de retificação possui como características o bom acabamento superficial e alta precisão dimensionale geométrica. Assim, peças usinadas por este processo possuem um alto valor agregado por se tratar deum processo de acabamento que é comumente realizado nas últimas etapas da fabricação. Um fator limitadordo processo de retificação é a quantidade de calor gerada, a qual é minimizada pela aplicação de fluidos decorte. Os fluidos utilizados, na maior parte dos casos são poluentes e contém substâncias que são nocivas àsaúde e ao meio ambiente, além do mesmo possuir um alto custo de compra, manutenção e descarte. Visandoreduzir a quantidade de fluido utilizada durante o processo de retificação, o presente trabalho foi desenvolvido.O seu principal objetivo é melhorar a técnica da mínima quantidade de lubrificação através da aplicaçãocombinada com ar comprimido a baixa temperatura. Esta aplicação visa aumentar o efeito de refrigeração eassim minimizar a geração de calor na região de corte. Para avaliar a eficácia da técnica foram analisados osparâmetros de rugosidade, circularidade, desgaste do rebolo e potência consumida durante a usinagem. Estesvalores foram medidos para três métodos distintos de aplicação de fluidos de corte durante o processo deretificação, a fim de compará-los. A técnica de lubri-refrigeração convencional obteve melhores resultadospara os parâmetros analisados, ficando a técnica de CAMQL (mínima quantidade de fluido combinado com aaplicação de ar comprimido resfriado) com resultados intermediários e a técnica de MQL (mínima quantidadede lubrificação) com os piores resultados obtidos em todos os parâmetros. A técnica proposta de reduçãode quantidade de fluido utilizada atingiu, em geral, resultados positivos, provando a viabilidade da mesmapara a retificação do aço AISI 4340 utilizando rebolo de CBN, o Nitreto Cúbico de Boro, um superabrasivocom capacidade de corte inferior apenas ao diamante.Palavras-chave: Retificação, Rebolo de CBN, CAMQL, ar frio, aço AISI 4340

Physical distancing and mental well-being in youth population of Portugal and Brazil during the COVID-19 pandemic

Funding Information: This paper was made possible with the scholarship from FCT and to the Unidade de I&D CHRC – Comprehensive Health Research Centre (UI/BD/150908/2021). Also to CAPES (Code 001) and CNPQ (Research Productivity Scholarship Process 304483/2018-4). The databases are anonymous, guaranteeing data confidentiality. Funding Information: Fundação para a ciência e tecnologia (FCT) and the Unidade de I&D CHRC – Comprehensive Health Research Centre (UI/BD/150908/2021). Also to CAPES (Code 001) and CNPQ (Research Productivity Scholarship Process 304483/2018-4) Publisher Copyright: © 2022Background: The COVID-19 pandemic may affect youth's physical and mental well-being, partially because of the countries' rules to contain the virus from spreading. However, there is still uncertainty about the impact of physical distancing on youth's mental health. We aimed to estimate the prevalence of feeling agitated, anxious, down, sad, or low mood (FNF) due to physical distance measures and verify which factors are associated with young Portuguese and Brazilian people. Methods: We used cross-sectional data from the instrument "COVID-19 Barometer: Social Opinion"in Portugal (March 2020 and September 2021) and from "COVID-19 Social Thermometer"in Brazil (August 2020 to April 2021); these surveys included data regarding the health and socioeconomic impact on the population. The health and sociodemographic variables of the two countries were summarized as absolute and relative frequencies. A multivariable logistic regression model was fit by country to estimate the relation between FNF and selected variables of interest. Results: Approximately 36% of the sample studied reported anxiety, agitation, sadness, or low mood almost every day in Portugal and 52% in Brazil due to physical distancing. In Portugal, having more than two comorbidities represented a greater chance of experiencing FNF every day or almost every day (odds ratio [OR] = 1.51 [CI: 1.22-1.87]) than those without comorbidities. In contrast, having a university education level represented a protector factor (OR = 0.76 [CI: 0.67-0.88]). In Brazil, being unemployed increased the chance of FNF compared to students (OR = 11.2). Conclusions: Physical distancing measures have impacted the mental well-being of the young population in Portugal and Brazil. The countries must make a quick effort to attend to and protect young people's well-being and mental health in the changing context of the current pandemic.publishersversioninpres

Photobiomodulation Therapy at 808 nm Does Not Improve Biceps Brachii Performance to Exhaustion and Delayed-Onset Muscle Soreness in Young Adult Women: A Randomized, Controlled, Crossover Trial

ObjectiveThis study aims to investigate the effects of laser photobiomodulation (PBM) at 808 nm on biceps brachii performance to exhaustion, rating of perceived exertion (RPE), and delayed onset muscle soreness (DOMS) in untrained young women.MethodsThirteen young women (20.1 ± 2.9 years) participated in a crossover study in which they received, in a counterbalanced manner, active and placebo laser PBM on two occasions (T1 and T2), separated by a 7-day washout period. During T1 and T2, participants received active (100 mW output power, irradiance of 35.7 W cm–2, and total energy of 28 J/arm) or placebo laser irradiation on the biceps brachii muscle at 20 min before the repetitions-to-failure test [six sets at 60% of one-repetition maximum (1RM) until failure] for elbow flexion exercise. The number of repetitions performed and RPE over the six sets, as well as DOMS from basal up to 72 h after the repetitions-to-failure test, were recorded.ResultsThere was a significant (time, p < 0.05) reduction in the number of repetitions performed and an increase in RPE over six sets, with no statistical differences between placebo and active laser conditions (treatment × time, p > 0.05). DOMS increased at 24 h postexercise and progressively returned to baseline after 72 h in both conditions (time, p < 0.05; treatment × time, p > 0.05).ConclusionOur results indicate that acute laser PBM at 808 nm does not improve biceps brachii performance to exhaustion, RPE, and DOMS in untrained women