Multirate sampled-data yaw-damper and modal suppression system design

A multirate control law synthesized algorithm based on an infinite-time quadratic cost function, was developed along with a method for analyzing the robustness of multirate systems. A generalized multirate sampled-data control law structure (GMCLS) was introduced. A new infinite-time-based parameter optimization multirate sampled-data control law synthesis method and solution algorithm were developed. A singular-value-based method for determining gain and phase margins for multirate systems was also developed. The finite-time-based parameter optimization multirate sampled-data control law synthesis algorithm originally intended to be applied to the aircraft problem was instead demonstrated by application to a simpler problem involving the control of the tip position of a two-link robot arm. The GMCLS, the infinite-time-based parameter optimization multirate control law synthesis method and solution algorithm, and the singular-value based method for determining gain and phase margins were all demonstrated by application to the aircraft control problem originally proposed for this project

Multirate flutter suppression system design for the Benchmark Active Controls Technology Wing

To study the effectiveness of various control system design methodologies, the NASA Langley Research Center initiated the Benchmark Active Controls Project. In this project, the various methodologies will be applied to design a flutter suppression system for the Benchmark Active Controls Technology (BACT) Wing (also called the PAPA wing). Eventually, the designs will be implemented in hardware and tested on the BACT wing in a wind tunnel. This report describes a project at the University of Washington to design a multirate flutter suppression system for the BACT wing. The objective of the project was two fold. First, to develop a methodology for designing robust multirate compensators, and second, to demonstrate the methodology by applying it to the design of a multirate flutter suppression system for the BACT wing. The contributions of this project are (1) development of an algorithm for synthesizing robust low order multirate control laws (the algorithm is capable of synthesizing a single compensator which stabilizes both the nominal plant and multiple plant perturbations; (2) development of a multirate design methodology, and supporting software, for modeling, analyzing and synthesizing multirate compensators; and (3) design of a multirate flutter suppression system for NASA's BACT wing which satisfies the specified design criteria. This report describes each of these contributions in detail. Section 2.0 discusses our design methodology. Section 3.0 details the results of our multirate flutter suppression system design for the BACT wing. Finally, Section 4.0 presents our conclusions and suggestions for future research. The body of the report focuses primarily on the results. The associated theoretical background appears in the three technical papers that are included as Attachments 1-3. Attachment 4 is a user's manual for the software that is key to our design methodology

The Uncoupling Protein 1 Gene (UCP1) Is Disrupted in the Pig Lineage: A Genetic Explanation for Poor Thermoregulation in Piglets

Piglets appear to lack brown adipose tissue, a specific type of fat that is essential for nonshivering thermogenesis in mammals, and they rely on shivering as the main mechanism for thermoregulation. Here we provide a genetic explanation for the poor thermoregulation in pigs as we demonstrate that the gene for uncoupling protein 1 (UCP1) was disrupted in the pig lineage. UCP1 is exclusively expressed in brown adipose tissue and plays a crucial role for thermogenesis by uncoupling oxidative phosphorylation. We used long-range PCR and genome walking to determine the complete genome sequence of pig UCP1. An alignment with human UCP1 revealed that exons 3 to 5 were eliminated by a deletion in the pig sequence. The presence of this deletion was confirmed in all tested domestic pigs, as well as in European wild boars, Bornean bearded pigs, wart hogs, and red river hogs. Three additional disrupting mutations were detected in the remaining exons. Furthermore, the rate of nonsynonymous substitutions was clearly elevated in the pig sequence compared with the corresponding sequences in humans, cattle, and mice, and we used this increased rate to estimate that UCP1 was disrupted about 20 million years ago

Diabetes Disease Management in a Community-Based Setting

through 1 year. Differences in behavior are compared at program intake and at a 6-month reassessment. Differences in medical-service utilization are compared in the baseline year and the year subsequent to program enrollment. Poisson multivariateregression models are estimated for counts of inpatient, emergency department, physician evaluation and management, and facility visits, while also controlling for potential confounders. Principal findings. Behaviors improved between program intake and the 6-month reassessment. From patient reports, the number of participants having a hemoglobin A 1c test increased by 44.9 percent (p<.001), and there was a 53.2-percent decrease in symptoms of hyperglycemia (p=.002). From medical claims after program enrollment, a drop occurred during the program year in every dimension of medical-service utilization. Regression results show that inpatient admissions decreased by 391 (p<.001) per 1,000 for each group, while controlling for age, length of membership, and the number of comorbid claims for congestive heart failure. In the analysis of costs that were pre-and post-enrollment, which included disease-management program costs, a 4.34:1 return on investment was calculated. Conclusion. The diabetes program provides patients with comprehensive information and counseling relative to practicing self-management of diabetes through a number of integrated program components. This study strongly suggests that the implementation of such a program is associated with positive behavioral change and, thus, with substantial reduction in medical-service utiliza

Viscosity of Xenon Examined in Microgravity

Why does water flow faster than honey? The short answer, that honey has a greater viscosity, merely rephrases the question. The fundamental answer is that viscosity originates in the interactions between a fluid s molecules. These interactions are so complicated that, except for low-density gases, the viscosity of a fluid cannot be accurately predicted. Progress in understanding viscosity has been made by studying moderately dense gases and, more recently, fluids near the critical point. Modern theories predict a universal behavior for all pure fluids near the liquid-vapor critical point, and they relate the increase in viscosity to spontaneous fluctuations in density near this point. The Critical Viscosity of Xenon (CVX) experiment tested these theories with unprecedented precision when it flew aboard the Space Shuttle Discovery (STS-85) in August 1997. Near the critical point, xenon is a billion times more compressible than water, yet it has about the same density. Because the fluid is so "soft," it collapses under its own weight when exposed to the force of Earth s gravity - much like a very soft spring. Because the CVX experiment is conducted in microgravity, it achieves a very uniform fluid density even very close to the critical point. At the heart of the CVX experiment is a novel viscometer built around a small nickel screen. An oscillating electric field forces the screen to oscillate between pairs of electrodes. Viscosity, which dampens the oscillations, can be calculated by measuring the screen motion and the force applied to the screen. So that the fluid s delicate state near the critical point will not be disrupted, the screen oscillations are set to be both slow and small

Information shocks and the empirical evaluation of training programs during unemployment spells

We study the role of notifications in the evaluation of training programs for unemployed workers. Using a unique administrative data set containing the dates when information is exchanged between job seekers and caseworkers, we address three questions: Do information shocks, such as notification of future training, have an effect on unemployment duration? What is the joint effect of notification and training programs on unemployment? Can ignoring information shocks lead to a large bias in the estimation of the effect of training programs? We discuss these issues through the lens of a job search model and then conduct an empirical analysis following a “random effects” approach to deal with selectivity. We find that notification has a strong positive effect on the training probability but a negative one on the probability of leaving unemployment. This “attraction” effect highlights the importance of accounting for notifications in the evaluation of active labor market policies

Review Of The Main Welfare Risks Related To Electrical Stunning Of Small Ruminants (Ovine And Caprine Species)

EFSA commissioned a comprehensive review of the welfare aspects of electrical stunning methods for small ruminants with an emphasize on low ampere stunning to establish the state of the art in the field and to assess whether scientific studies would address criteria outlined in an EFSA guidance on the assessment criteria for studies evaluating the effectiveness of stunning interventions regarding animal protection at the time of killing (EFSA Journal 2013;11(12):3486). The review was not formulated as a systematic review with a focused question instead the review followed the approach to assessing the literature described by the EFSA guidance. The key databases searched were: Science Citation Index (1900-2014), CAB Abstracts (1910-2014) and Medline (1990-2014). Key conferences proceedings and the bibliographies of review articles were manually searched. The search yielded 1599 records. 706 duplicate records were removed and 894 records assessed for relevance. Relevant studies reported electronic stunning of small ruminants and outcomes associated with onset and duration of unconsciousness. Eighteen papers reported electrical approaches to stunning in sheep. No goats were studied. None of the papers reported all of the parameters detailed in the EFSA guidance (EFSA, 2013) and a risk of bias assessment was not conducted. No studies reported the appearance of the electrodes. When the frequency (Hz) applied to the animal was reported, it was not specified whether this represented a minimum or maximum frequency. Only one study explicitly reported an effect size for amperes. The study suggested that the odds of a poor stun were higher for amperes of 0.6 (odds ratio (OD) of 6.27 with 95% confidence interval (CI) of 1.98-20.7) and 0.8 (OR of 24.4 with 95% CI of 6.98-85.2) when compared to a poor stun at 1.25 ampere

Nano-inclusion in one step: spontaneous ice-templating of porous hierarchical nanocomposites for selective hydrogen release

3-Dimensional porous scaffold materials can be fabricated by ice templating sheets of graphene oxide (GO) or partially reduced graphene oxide (rGO). Aqueous suspensions of GO (or rGO) can be cast into monoliths or formed as beads on cooling and the solid matrices then fashioned with either laminar or radial porosity as result. Further, ammonia borane (AB) can be integrated into the hierarchical structures in situ in a one-step process without the requirement of melt infiltration or solution impregnation techniques. Compared to AB itself, the ensuing self-assembled beads release hydrogen at a reduced onset temperature and without volume expansion on heating, suppressing the release of diborane, borazine and ammonia. Pre-reduction of the GO matrix material (to rGO) eliminates CO/CO2 release from the composites

On The Inflaton Potential From Antibranes in Warped Throats

We compute the force between a stack of smeared antibranes at the bottom of a warped throat and a stack of smeared branes at some distance up the throat, both for anti-D3 branes and for anti-M2 branes. We perform this calculation in two ways: first, by treating the antibranes as probes in the background sourced by the branes and second, by treating the branes as probes in the candidate background sourced by the antibranes. These two very different calculations yield exactly the same expression for the force, for all values of the brane-antibrane separation. This indicates that the force between a brane and an antibrane is not screened in backgrounds where there is positive charge dissolved in flux, and gives a way to precisely compute the inflaton potential in certain string cosmology scenarios.Comment: 9 page