University of Virginia

About: University of Virginia is a education organization based out in Charlottesville, Virginia, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 52543 authors who have published 113268 publications receiving 5220506 citations. The organization is also known as: U of V & UVa.

Basis expansion models and diversity techniques for blind identification and equalization of time-varying channels

Abstract: The time-varying impulse response of rapidly fading mobile communication channels is expanded over a basis of complex exponentials that arise due to Doppler effects encountered with multipath propagation. Blind methods are reviewed for estimating the bases' parameters and the model orders. Existing second-order methods are critiqued and novel algorithms are developed for blind identification, direct, zero-forcing equalization and minimum mean square error (MMSE) equalization by combining channel diversity with temporal (fractional sampling) and/or spatial diversity which becomes available with multiple receivers. Illustrative simulations are also presented.

Beyond reciprocity: gratitude and relationships in everyday life

Abstract: The emotion of gratitude is thought to have social effects, but empirical studies of such effects have focused largely on the repaying of kind gestures. The current research focused on the relational antecedents of gratitude and its implications for relationship formation. The authors examined the role of naturally occurring gratitude in college sororities during a week of gift-giving from older members to new members. New members recorded reactions to benefits received during the week. At the end of the week and 1 month later, the new and old members rated their interactions and their relationships. Perceptions of benefactor responsiveness predicted gratitude for benefits, and gratitude during the week predicted future relationship outcomes. Gratitude may function to promote relationship formation and maintenance.

The Classroom Assessment Scoring System: Findings from the prekindergarten year.

Abstract: Research on teacher-child relationships, classroom environments, and teaching practices provided the rationale for constructing a system for observing and assessing emotional and instructional elements of quality in early childhood educational environments: the Classroom Assessment Scoring System (CLASS). The CLASS provides a framework for observing key dimensions of classroom processes, such as emotional and instructional support, that contribute to quality of the classroom setting from preschool through third grade. This article provides information about the development, field testing, and use of this instrument in prekindergarten. Data from a national sample of 224 prekindergarten classrooms in 6 states are presented to provide reliability and validity information. The full range of the scale was used for the majority of ratings. Ratings reflected generally positive impressions of the classroom environment and teacher-child interactions. Factor scores from the CLASS were related to the Early Childhood...