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.

A new method for site suitability analysis: The analytic hierarchy process

Abstract: A critical shortcoming of methods that are reliant upon the judgment of experts to determine site suitability is noted. The article introduces a new method, the analytic hierarchy process (AHP) with which error in judging the relative importance of factors in site suitability analysis can be both detected and corrected. The proposed approach is illustrated with an example to show how the AHP frames the site evaluation problem and can aid in decision making involving multiple criteria, factor diversity, and conditions of uncertainty. The article concludes by suggesting the potential application of the AHP in public choice decisions involving complex, controversial, and conflictual site selection processes.

Language Experience in the Second Year of Life and Language Outcomes in Late Childhood

Abstract: OBJECTIVES: Quantity of talk and interaction in the home during early childhood is correlated with socioeconomic status (SES) and can be used to predict early language and cognitive outcomes We tested the effectiveness of automated early language environment estimates for children 2 to 36 months old to predict cognitive and language skills 10 years later and examined effects for specific developmental age periods METHODS: Daylong audio recordings for 146 infants and toddlers were completed monthly for 6 months, and the total number of daily adult words and adult-child conversational turnswere automatically estimated with Language Environment Analysis software Follow-up evaluations at 9 to 14 years of age included language and cognitive testing Language exposure for 3 age groups was assessed: 2 to 17 months, 18 to 24 months, and ≥25 months Pearson correlations and multiple linear regression analyses were conducted RESULTS: Conversational turn counts at 18 to 24 months of age accounted for 14% to 27% of the variance in IQ, verbal comprehension, and receptive and/or expressive vocabulary scores 10 years later after controlling for SES Adult word counts between 18 and 24 months were correlated with language outcomes but were considerably weakened after controlling for SES CONCLUSIONS: These data support the hypothesis that early talk and interaction, particularly during the relatively narrow developmental window of 18 to 24 months of age, can be used to predict school-age language and cognitive outcomes With these findings, we underscore the need for effective early intervention programs that support parents in creating an optimal early language learning environment in the home

Software maintenance management: changes in the last decade

Abstract: Compared to a decade ago, when the first comprehensive study was done in software maintenance, many changes have occurred in the practice of system development. Longitudinal data were obtained by using the same survey instrument, updated to reflect current practices, and sampling the same population. Comparing the current with 1977 results has helped to identify the persistent problems and issues as well as the emerging problems and issues. One of the important, but somewhat disturbing, conclusions is that maintenance problems are pretty much the same as during the 1970s (except for minor changes), despite advances made in structured methodologies and techniques. In terms of specific problems, personnel problems of maintenance programmers, i.e. turnover and availability, and programmer effectiveness problems, i.e. skills, motivation and productivity, have shown a rise, while problems associated with users' knowledge of computer systems have declined.

Selection and Scaling of Ground Motion Time Histories for Structural Design Using Genetic Algorithms

Abstract: This paper presents a new approach to selection of a set of recorded earthquake ground motions that in combination match a given site-specific design spectrum with minimum alteration. The scaling factors applied to selected ground motions are scalar values within the range specified by the user. As a result, the phase and shape of the response spectra of earthquake ground motions are not tampered with. Contrary to the prevailing scaling methods where a preset number of earthquake records (usually between a single component to seven pairs) are selected first and scaled to match the design spectrum next, the proposed method is capable of searching a set consisting of thousands of earthquake records and recommending a desired subset of records that match the target design spectrum. This task is achieved by using a genetic algorithm (GA), which treats the union of 7 records and corresponding scaling factors as a single ‘‘individual.’’ The first generation of individuals may include a population of, for example, 200 records. Then, through processes that mimic mating, natural selection, and mutation, new generations of individuals are produced and the process continues until an optimum individual (seven pairs and scaling factors) is obtained. The procedure is fast and reliable and results in records that match the target spectrum with minimal tampering and the least mean square of deviation from the target spectrum. [DOI: 10.1193/1.1719028]