The BSCS and Educational Computing in the Sciences

This is the publisher's version, also found at http://www.jstor.org/stable/444823

Supersonic aeroelastic instability results for a NASP-like wing model

An experimental study and an analytical study have been conducted to examine static divergence for hypersonic-vehicle wing models at supersonic conditions. A supersonic test in the Langley Unitary Plan Wind Tunnel facility was conducted for two wind-tunnel models. These models were nearly identical with the exception of airfoil shape. One model had a four-percent maximum thickness airfoil and the other model had an eight-percent maximum thickness airfoil. The wing models had low-aspect ratios and highly swept leading edges. The all-movable wing models were supported by a single-pivot mechanism along the wing root. For both of the wind-tunnel models, configuration changes could be made in the wing-pivot location along the wing root and in the wing-pivot pitch stiffness. Three divergence conditions were measured for the four-percent thick airfoil model in the Mach number range of 2.6 to 3.6 and one divergence condition was measured for the eight-percent thick airfoil model at a Mach number of 2.9. Analytical divergence calculations were made for comparison with experimental results and to evaluate the parametric effects of wing-pivot stiffness, wing-pivot location, and airfoil thickness variations. These analyses showed that decreasing airfoil thickness, moving the wing-pivot location upstream, or increasing the pitch-pivot stiffness have the beneficial effect of increasing the divergence dynamic pressures. The calculations predicted the trend of experimental divergence dynamic pressure with Mach number accurately; however, the calculations were approximately 25 percent conservative with respect to dynamic pressure

Roach infestation optimization

Abstract only availableThere are many function optimization algorithms based on the collective behavior of natural systems — Particle Swarm Optimization (PSO) and Ant Colony Optimization (ACO) are two of the most popular. This poster presents a new adaptation of the PSO algorithm, entitled Roach Infestation Optimization (RIO), which is inspired by recent discoveries in the social behavior of cockroaches. We present the development of the simple behaviors of the individual agents, which emulate some of the discovered cockroach social behaviors. We also describe a "hungry" version of the PSO and RIO, which we aptly call Hungry PSO and Hungry RIO. Comparisons with standard PSO show that Hungry PSO, RIO, and Hungry RIO are all more effective at finding the global optima of a suite of test functions.College of Engineering Undergraduate Research Optio

Modeling the flow of digesta through the ruminant reticulorumen

Abstract only availableRuminants possess a specialized gastrointestinal (GI) tract that enables them to efficiently digest fibrous feeds. The first stomach compartment of the ruminant GI tract, the reticulorumen (RR), is the site of most fiber digestion due to the presence of cellulolytic microorganisms in conjunction with selective retention of feed particles; undigested fibrous feed particles are selectively retained and fermented by cellulolytic microorganisms in the RR until certain digestive processes are completed, enabling the particles to pass. Selective retention and the overall process of digesta flow in the RR affect feed digestibility, feed intake, and microbial efficiency—all important animal performance parameters in ruminant production. It is imperative to model digesta flow in the RR to better predict these animal performance parameters for use in ruminant production systems. Mathematical models have indeed been developed to describe the flow of digesta in the RR, typically with the RR represented as one or more mathematical compartments with flow between compartments defined by kinetic rate variables or constants. Mathematical models developed to the present use either fractional rate constants or rate variables based on the gamma distribution. The Yule distribution has also been suggested for modeling RR digesta flow kinetics, but its development has been cursory. It remains unseen what, if any, benefits may arise from applying the Yule distribution to describe the kinetics of RR digesta. In this study, a model incorporating the Yule distribution is fully developed. Physiological justification for using the Yule distribution is also provided on the basis of selective retention. A comparison between the model developed herein and a previously published model using the gamma distribution reveals that both models give similar mathematical results under certain cases. Still, it is suggested that the physiological relevance of the model treated here may make it superior. Animal feeding trials are currently being conducted to validate the structure of model. Additionally, mathematical models are being developed to describe small and large intestinal flow in ruminant and non-ruminant species, thereby expanding this modeling effort to include most of the GI tract.Life Sciences Undergraduate Research Opportunity Progra

Total mixed dairy rations on your farm? (1991)

Total mixed dairy rations (TMR) offer an opportunity to improve business profits through improved animal performance and health, decreased feed wastage, improved labor efficiency and improved butterfat. The installation of a TMR system normally requires added investments in feed mixing and distribution equipment. The purpose of this publication is to provide a format for evaluating the economic consequences of changing to a TMR system.Reviewed October 1993 -- Extension website

THE EFFECTS OF AUTOMATION EXPERTISE AND SYSTEM CONFIDENCE ON TRUST BEHAVIORS

Trust in automation is more likely to be appropriate when information about the automation's capability is available. The goal of this study was to determine how automation expertise and system confidence affected automation trust behaviors. Forty-one participants completed a target detection task while receiving advice from an imperfect diagnostic aid that varied in expertise (expert vs. novice) and confidence (75% vs. 50% vs. 25%, no aid). Results showed that participants were more willing to comply with the highly confident expert aid than the highly confident novice aid. Furthermore, participants were more apt to generate false alarms as system confidence increased. These results suggest that, similar to interpersonal relationships, humans appraise automation features such as confidence and expertise when deciding to comply with automation. Implications and direction for future research are discussed

How to reduce heat stress in dairy cattle (1993)

Reviewed October 1993