Free-flight wind-tunnel investigation of a four-engine sweptwing upper-surface blown transport configuration

The dynamic stability and control characteristics of a four-engine turbofan transport model having an upper-surface blown jet flap were investigated by means of the free-flight technique in the Langley full-scale tunnel. The flight characteristics of the model were investigated through a range of lift coefficients from 3 to 8 with all four engines operating and with one outboard engine not operating. Static characteristics were investigated by conventional power-on force tests over the flight-test angle-of-attack range and through the stall

Linear algebra meets Lie algebra: the Kostant-Wallach theory

In two languages, Linear Algebra and Lie Algebra, we describe the results of Kostant and Wallach on the fibre of matrices with prescribed eigenvalues of all leading principal submatrices. In addition, we present a brief introduction to basic notions in Algebraic Geometry, Integrable Systems, and Lie Algebra aimed at specialists in Linear Algebra.Comment: 27 pages, LaTeX; abstract adde

Low speed wind tunnel tests of 1/10-scale model of a blended-arrow supersonic cruise aircraft

Low speed static force tests have been conducted in a full scale tunnel to determine the low speed aerodynamic characteristics of a 1/10-scale model of a blended-arrow supersonic cruise aircraft. A clean configuration and a high lift configuration with several combinations of leading- and trailing-edge flaps to provide improved lift and longitudinal stability in the landing and takeoff modes were used. The tests were made at angles of attack from about -6 deg to 30 deg, sideslip angles from -5 deg to 10 deg, and Reynolds numbers from 6.78 x 1 million to 13.85 x 1 million corresponding to test velocities of 41 to 85 knots

The Lanczos algorithm with selective orthogonalization

A new stable and efficient implementation of the Lanczos algorithm is presented. The algorithm is a powerful method for finding a few eigenvalues and eigenvectors at one or both ends of the spectrum of a symmetric matrix A. The algorithm is particularly effective if A is large and sparse in that the only way in which A enters the calculation is through a subroutine which computes Av for any vector v. Thus the user is free to take advantage of any sparsity structure in A and A need not even be represented as a matrix et al

A new look at the Lanczos algorithm for solving symmetric systems of linear equations

AbstractSimple versions of the conjugate gradient algorithm and the Lanczos method are discussed, and some merits of the latter are described. A variant of Lanczos is proposed which maintains robust linear independence of the Lanczos vectors by keeping them in secondary storage and occasionally making use of them. The main applications are to problems in which (1) the cost of the matrix-vector product dominates other costs, (2) there is a sequence of right hand sides to be processed, and (3) the eigenvalue distribution of A is not too favorable

Exploring Age-Related Metamemory Differences Using Modified Brier Scores and Hierarchical Clustering

Older adults (OAs) typically experience memory failures as they age. However, with some exceptions, studies of OAs’ ability to assess their own memory functions– Metamemory (MM)– find little evidence that this function is susceptible to age-related decline. Our study examines OAs’ and young adults’ (YAs) MM performance and strategy use. Groups of YAs (N = 138) and OAs (N = 79) performed a MM task that required participants to place bets on how likely they were to remember words in a list. Our analytical approach includes hierarchical clustering, and we introduce a new measure of MM—the modified Brier—in order to adjust for di↵erences in scale usage between participants. Our data indicate that OAs and YAs di↵er in the strategies they use to assess their memory and in how well their MM matches with memory performance. However, there was no evidence that the chosen strategies were associated with di↵erences in MM match, indicating that there are multiple strategies that might be e↵ective (i.e. lead to similar match) in this MM task

The Impact of Student Choice on Motivation for Struggling Readers to Complete Reading Activities

How do teachers motivate their students to learn? Prompt, induce, or inspire – whatever word is used, educators recognize the importance of understanding students as individuals with idiosyncratic learning styles and the challenge of implementing the best practice for each. Former research in this subject defines the two types of motivation as intrinsic and extrinsic. This research project investigates and reports on the query, does giving student choices in reading activities impact their desire to learn? The purpose of this qualitative study was to explore different forms of motivation, driven by student choice as a catalyst, for learning in the classroom with particular attention given to struggling readers. The study took place in a fourth-grade classroom during a reader\u27s workshop and focused on four student test subjects. The specific student interviews and surveys posed several questions regarding: student choice motivation, self-assessment as readers, autonomy as a learner, group versus individual activities, use of reading centers, and the like. Conclusions drawn from the research data analysis confirm that collaborative learning has positive effects on students regardless of their reading status and proves to be a significant motivator for learning