Integrated controls/structures study of advanced space systems

A cost tradeoff is postulated for a stiff structure utilizing minimal controls (and control expense) to point and stabilize the vehicle. Extra costs for a stiff structure are caused by weight, packaging size, etc. Likewise, a more flexible vehicle should result in reduced structural costs but increased costs associated with additional control hardware and data processing required for vibration control of the structure. This tradeoff occurs as the ratio of the control bandwidth required for the mission to the lowest (significant) bending mode of the vehicle. The cost of controlling a spacecraft for a specific mission and the same basic configuration but varying the flexibility is established

Health Research Participants' Preferences for Receiving Research Results

BACKGROUND: Participants in health research studies typically express interest in receiving results from the studies in which they participate. However, participants’ preferences and experiences related to receiving results are not well understood. In general, existing studies have had relatively small sample sizes and typically address specific and often sensitive issues within targeted populations. METHODS: The present study used an online survey to explore attitudes and experiences of registrants in ResearchMatch, a large database of past, present, and potential health research participants. Survey respondents provided information related to whether or not they received research results from studies in which they participated, the methods used to communicate results, their satisfaction with results, and when and how they would like to receive research results from future studies. 70,699 ResearchMatch registrants were notified of the study’s topic. Of the 5,207 registrants who requested full information about the study, 3,381 respondents completed the survey. RESULTS: Approximately 33% of respondents with previous health research participation reported receiving results. Approximately half of respondents with previous research participation reported no opportunity to request results. However, almost all respondents said researchers should always or sometimes offer results to participants. Respondents expressed particular interest in results related to their (or a loved one's) health, as well as information about studies’ purposes and any medical advances based on the results. In general, respondents’ most preferred dissemination methods for results were email and website postings. The least desirable dissemination methods for results included Twitter, conference calls, and text messages. Across all results, we compare the responses of respondents with and without previous research participation experience, and those who have worked in research organizations vs. those who have not. Compared to respondents who have previous participation experience, a greater proportion of respondents with no participation experience indicated that results should always be shared with participants. Likewise, respondents with no participation experience placed higher importance on the receipt of each type of results information included in the survey. CONCLUSIONS: We present findings from a survey assessing attitudes and experiences of a broad sample of respondents that addresses gaps in knowledge related to participants’ preferences for receiving results. The study’s findings highlight the potential for inconsistency between respondents’ expressed preferences to receive specific types of results via specific methods and researchers’ unwillingness or inability to provide them. We present specific recommendations to shift the approach of new studies to investigate participants’ preferences for receiving research results

Kalman Filter Equalization For QPSK Communications

The discrete complex Kalman filter is considered as an equalizer for quadrature phase-shift keyed (QPSK) systems in the presence of additive noise and InterSymbol interference (ISI). When the channel is unknown, an adaptive Kalman equalizer is used in which the channel complex tap gains are estimated by decision feedback. Copyright © 1976 by The Institute of Electrical and Electronics Engineers, Inc

INTRA-LIMB JOINT COUPLING PATTERNS DURING THE USE OF THREE LOWER EXTREMITY EXERCISE MACHINES

The purpose of this study was to preliminarily describe sagittal plane joint coupling patterns for a spectrum of common lower extremity exercises. Each participant performed 3, 10 second sessions on a stationary bicycle, elliptical and treadmill. Intra-limb coupling angles of the hip and knee for two recreational athletes were quantified using vector coding techniques on randomly selected cycles from each movement. Variability patterns within the same movements were repeatable within and between each participant while each movement’s distinguishable variability pattern differed both spatially and temporally between pieces of exercise equipment. These findings suggest that each exercise machine studied is distinguishable characteristics in its variability pattern. Comparison of variability patterns might be a useful method in the design of functional training exercises to aid in optimally mimicking task kinematics

Efficient Unsteady Model Estimation Using Computational and Experimental Data

Improving aircraft simulations for pilot training in loss-of-control and stalled conditions is one goal of NASA research in the System Wide Safety Program. One part of this effort is to develop appropriate generic aerodynamic models that provide representative responses in simulation for a given class of aircraft. In this part of the flight envelope nonlinear unsteady responses are often present and may require an extended aerodynamic model compared to that used in the conventional flight envelope. In this preliminary study, two objectives are addressed. First, to obtain a representative model for a NASA generic aircraft at an unsteady condition in the flight envelope and second, to evaluate the techniques involved. To meet these objectives, two different generic aircraft configurations are modeled using both experimental and analytical data. With these results, an initial assessment of the efficiency and quality of the tools and test techniques are evaluated to develop guidance for analytical and experimental approaches to unsteady modeling

Late-Time Behavior of Stellar Collapse and Explosions: I. Linearized Perturbations

Problem with the figures should be corrected. Apparently a broken uuencoder was the cause.Comment: 16pp, RevTex, 6 figures (included), NSF-ITP-93-8

Applying black hole perturbation theory to numerically generated spacetimes

Nonspherical perturbation theory has been necessary to understand the meaning of radiation in spacetimes generated through fully nonlinear numerical relativity. Recently, perturbation techniques have been found to be successful for the time evolution of initial data found by nonlinear methods. Anticipating that such an approach will prove useful in a variety of problems, we give here both the practical steps, and a discussion of the underlying theory, for taking numerically generated data on an initial hypersurface as initial value data and extracting data that can be considered to be nonspherical perturbations.Comment: 14 pages, revtex3.0, 5 figure

MOTOR CONTROL PATTERNS IN ELITE SWIMMERS’ FREESTYLE STROKE DURING DRYLAND SWIMMING

The purpose of this study was to compare motor control patterns of elite freestyle swimmers when asked to swim at 100m freestyle pace using a dryland swimbench. Collegiate and masters level swimmers (n=15) whose 100m freestyle time were faster than 75% of the FINA cutoff time, performed four 10 second trials of freestyle swimming on a dryland swimbench. 3-D kinematic analysis was used to calculate displacement in the hand in the cranial-caudal, vertical, and medial-lateral directions. A 2-way repeated measures ANOVA was used to compare hand path between swimmers and within trials (n=58). Data was not statically significant, but three distinct combinations of hand paths were used to perform the 100m freestyle task on the swimbench. These hand paths differed from historical in-water data. Findings imply individual swimmers adjusted kinematics on the swimbench to accommodate for environmental constraints

Computational Study of a Generic T-tail Transport

This paper presents a computational study on the static and dynamic stability characteristics of a generic transport T-tail configuration under a NASA research program to improve stall models for civil transports. The NASA Tetrahedral Unstructured Software System (TetrUSS) was used to obtain both static and periodic dynamic solutions at low speed conditions for three Reynolds number conditions up to 60 deg angle of attack. The computational results are compared to experimental data. The dominant effects of Reynolds number for the static conditions were found to occur in the stall region. The pitch and roll damping coefficients compared well to experimental results up to up to 40 deg angle of attack whereas yaw damping coefficient agreed only up to 20 deg angle of attack

Implementation frameworks for polypharmacy management within healthcare organisations: a scoping review.

Several guidelines support polypharmacy management in individual patients. More organisational-level focus is needed on the use of implementation frameworks. The aim of this scoping review was to characterise the peer-reviewed literature on implementation frameworks, focussing on barriers and facilitators to implementation at organisational level in the context of polypharmacy management. A scoping review protocol was devised, supporting retrieval of studies published in English, reporting from any sector of practice. Medline, International Pharmaceutical Abstracts, Cumulative Index of Nursing and Allied Health Literature and Business Source Complete were searched to January 2022 using Medical Subject Headings including: 'polypharmacy', 'deprescriptions', 'strategic planning' and 'organizational innovation'. A narrative approach to data synthesis was applied. Searching, data extraction and synthesis were undertaken independently by two reviewers. After screening 797 records, eight papers remained. Two were descriptive, outlining details of specific initiatives; six used qualitative methods to explore determinants for implementation, including barriers and enablers. Barriers at the organisation level included: poor organisational culture with a lack of sense of urgency and national plans, resource availability and communication issues including patient information and at transitions of care. Organisational facilitators included availability of government funding and regulatory environment promoting patient safety, a national emphasis on quality of care for older adults, co-ordinated national efforts and local evidence. Limited literature focusses on the use of implementation frameworks at organisational levels. This review highlights the need for further work on implementation frameworks in this context to help achieve effective organisational change