1,480 research outputs found
Competitive athletics for girls
Thesis (M.A.)--Boston University, 1933. This item was digitized by the Internet Archive
Interferometric molecular line observations of W51
Observations are presented of the H II region complex in W51 made with a mm interferometer. W51 is a region of massive star formation approx. 7 kpc distant from the sun. This region has been well studied in both the IR and submillimeter, the radio, as well as the maser transitions. These previous observations have revealed three regions of interest: (1) W51MAIN, a know of bright maser emission near two compact H II regions W51e1 and W51e2 (W51MAIN is also the peak of the 400 micron emission indicating that the bulk of the mass is centered there; (2) W51IRS1 is a long curving structure seen at 20 micron and at 2 and 6 cm but not at 400 micron; (3) W51IRS2 (also known as W51NORTH) is another compact H II region slightly offset from an 8 and a 20 micron peak and a collection of masers. Some conclusions are as follows: (1) SO and H(13)CN emission are similar and coincide with outflow activity; (2) HCO+ spectra show evidence for overall collapse of the W51 cloud toward W51MAIN; (3) A previously undetected continuum peak, W51DUST, coincides with the molecular peak H(13)CN-4; and (4) Dust emission at 3.4 mm reveals that about half of the 400 micron emission comes from the ultracompact H II region e2, and the rest from W51e1 and W51DUST
Meat buying and use in the Missouri restaurants
Digitized 2007 AES.Includes bibliographical references
Descriptive analysis of the Missouri restaurant industry
This bulletin is a report on Department of Agricultural Economics research project 386, 'Meat Marketing Economics'--P. [2].Digitized 2007 AES.Includes bibliographical references
SLICER: inferring branched, nonlinear cellular trajectories from single cell RNA-seq data
Accuracy of trajectory reconstruction using a subset of cells. (a) Graph showing how similar the SLICER trajectory is when computed using a random subset of lung cells. The blue bars show the similarity in cell ordering (units are percent sorted with respect to the trajectory constructed from all cells). The orange bars show the similarity in branch assignments (percentage of cells assigned to the same branch as the trajectory constructed from all cells). The values shown were obtained by averaging the results from five subsampled datasets for each percentage (80 %, 60 %, 40 %, and 20 %). (b) Order preservation and branch identity values computed as in panel (a), but for datasets sampled from the neural stem cell dataset. (PDF 106 kb
Reference Standards for Body Fat Measure Using GE Dual Energy X-Ray Absorptiometry in Caucasian Adults
Background Dual energy x-ray absorptiometry (DXA) is an established technique for the measurement of body composition. Reference values for these variables, particularly those related to fat mass, are necessary for interpretation and accurate classification of those at risk for obesityrelated health complications and in need of lifestyle modifications (diet, physical activity, etc.). Currently, there are no reference values available for GE-Healthcare DXA systems and it is known that whole-body and regional fat mass measures differ by DXA manufacturer.
Objective To develop reference values by age and sex for DXA-derived fat mass measurements with GE-Healthcare systems.
Methods A de-identified sample of 3,327 participants (2,076 women, 1,251 men) was obtained from Ball State University\u27s Clinical Exercise Physiology Laboratory and University of Wisconsin- Milwaukee\u27s Physical Activity & Health Research Laboratory. All scans were completed using a GE Lunar Prodigy or iDXA and data reported included percent body fat (%BF), fat mass index (FMI), and ratios of android-to-gynoid (A/G), trunk/limb, and trunk/leg fat measurements. Percentiles were calculated and a factorial ANOVA was used to determine differences in the mean values for each variable between age and sex.
Results Normative reference values for fat mass variables from DXA measurements obtained from GE-Healthcare DXA systems are presented as percentiles for both women and men in 10- year age groups. Women had higher (p\u3c0.01) mean %BF and FMI than men, whereas men had higher (p\u3c0.01) mean ratios of A/G, trunk/limb, and trunk/leg fat measurements than women
Business Models for Innovation in a MOSA Environment
Symposium PresentationApproved for public release; distribution is unlimited
Open for Business: Business Models for Innovation with Modular Open Systems Approaches
Excerpt from the Proceedings of the Nineteenth Annual Acquisition Research SymposiumModular Open Systems Approaches (MOSA) build on techniques used in the commercial world to attempt to bring innovation, speed, and savings to Department of Defense (DoD) acquisition. However, while competition can be a powerful motivator, MOSA can be disruptive to those traditional defense industrial base business models that rely on the expectation of long-term production and sustainment revenue to make back corporate investments. This project undertook interviews and surveys to better understand how MOSA influences vendor incentives and what business models may best serve DoD needs going forward. MOSA’s promise of enabling faster technology refresh and bringing in new sources of innovation addresses technical and operational challenges associated with 21st century great power competition and longstanding DoD difficulties in accessing commercial technology. This project has identified three overarching challenges regarding MOSA adoption: communicating and demonstrating government commitment; developing a MOSA-enabled IP and data rights strategy; and establishing standards and interfaces. In addressing these three challenges, the government will need to employ its acquisition toolkit to take different approaches with different vendors. To better understand how to make this transition a success, this paper presents a framework for evaluating the DoD’s readiness for MOSA.Approved for public release; distribution is unlimited
Real-Time Model-Free Deep Reinforcement Learning for Force Control of a Series Elastic Actuator
Many state-of-the art robotic applications utilize series elastic actuators
(SEAs) with closed-loop force control to achieve complex tasks such as walking,
lifting, and manipulation. Model-free PID control methods are more prone to
instability due to nonlinearities in the SEA where cascaded model-based robust
controllers can remove these effects to achieve stable force control. However,
these model-based methods require detailed investigations to characterize the
system accurately. Deep reinforcement learning (DRL) has proved to be an
effective model-free method for continuous control tasks, where few works deal
with hardware learning. This paper describes the training process of a DRL
policy on hardware of an SEA pendulum system for tracking force control
trajectories from 0.05 - 0.35 Hz at 50 N amplitude using the Proximal Policy
Optimization (PPO) algorithm. Safety mechanisms are developed and utilized for
training the policy for 12 hours (overnight) without an operator present within
the full 21 hours training period. The tracking performance is evaluated
showing improvements of N in mean absolute error when comparing the first
18 min. of training to the full 21 hours for a 50 N amplitude, 0.1 Hz sinusoid
desired force trajectory. Finally, the DRL policy exhibits better tracking and
stability margins when compared to a model-free PID controller for a 50 N chirp
force trajectory.Comment: 8 pages, 5 figures, submitted to IROS 202
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