University of Memphis

About: University of Memphis is a education organization based out in Memphis, Tennessee, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 7710 authors who have published 20082 publications receiving 611618 citations. The organization is also known as: U of M.

Wavelet-based AE characterization of composite materials

Abstract: This paper addresses an application of recently developed wavelet-based signal processing technique on a composite fracture behavior study. Here, the wavelet methodology is introduced, and a complete procedure of wavelet-based acoustic emission (AE) analysis methods developed by the author are demonstrated. In this research, the AE signals from glass fiber reinforced (GFR) composites are collected during the standard quasi-static tensile testing and transformed by the Daubechies discrete wavelets using the programs developed by the author. Based on AE tests, the fracture behaviors are studied for the material. In the study of GFR composite fracture behavior, classical linear fracture mechanics method is used for comparison. The exponential constant m value used to determine the relationship between stress and stress intensity factor are compared relative to the classical fracture mechanics and the AE techniques. In order to demonstrate the advantage of the wavelet-based AE techniques, the conventional AE analysis is also provided side-by-side for comparison. The results verify that the wavelet-based method better approximates residual strength relative to the classical AE techniques. In this paper, the results of the wavelet-based AE analysis of glass fiber composites are presented. The results indicate that wavelets-based signal processing is an efficient tool in the analysis and the transformation of AE signals.

Novel Word Learning in Children With Hearing Impairment

Abstract: This study examined novel word-learning abilities in young school-age children with mild-to-moderate hearing losses. We questioned whether degree of hearing loss or measures of language and phonolo...

The Development of Polysemy and Frequency Use in English Second Language Speakers

Abstract: Spoken language data were collected from six adult second language (L2) English learners over a year-long period in order to explore the development of word polysemy and frequency use. The data were analyzed both quantitatively and qualitatively. In the first analysis, the growth of WordNet polysemy values and CELEX word frequency values were examined. For both indexes, significant growth was demonstrated from the 2nd to the 16th week of observation, after which values remained stable. Growth in word polysemy values also correlated with changes in word frequency, supporting the notion that frequency and polysemy effects in word use are related. A second analysis used the WordNet dictionary to explore qualitative changes in word sense use concerning six frequent lexical items in the learner corpus (think, know, place, work, play, and name). A qualitative analysis compared normalized frequencies for each word sense in the first trimester of the study to the later trimesters. Differences in the number of word senses used across trimesters were found for all six words. Analyses 1 and 2, taken together, support the notion that L2 learners begin to use words that have the potential for more senses during the first 4 months; learners then begin to extend the core meanings of these polysemous words. These findings provide further insights into the development of lexical proficiency in L2 learners and the growth of lexical networks.

Exploring the Distinctive Nature of Work Commitments: Their Relationships with Personal Characteristics, Job Performance, and Propensity to Leave

Abstract: This study explores personal characteristics as antecedents to three types of work commitment: job, organizational, and career. Also, the relationships between these work commitments and key sales outcomes (performance and propensity to leave the organization) are assessed. We demonstrate the distinctive nature of these three work commitments while reducing the concept redundancy found between them and other forms of work commitment. The results indicate that each form of work commitment is uniquely related to a set of personal characteristics and sales outcomes. We also provide suggestions for future research and implications for sales managers.