228 research outputs found
Mission Operations, Cubed: NASA Marshall Operations Support for SmallSats
SmallSats have come a long way since the Huntsville Operations Support Center (HOSC) at NASA’s Marshall Space Flight Center supported its first “minisatellite” mission in 2010. And just as SmallSats themselves have evolved in those 12 years, so too has the HOSC’s mission support for SmallSats. Marshall Space Flight Center has a long history with payload and mission operations, including support for the Apollo missions to the moon, the Space Shuttle program, and 21 years of continuous around-the-clock science operations support for research aboard the International Space Station. Today, the HOSC is a multi-tenant facility, supporting not only ISS, but also NASA’s Commercial Crew program, the Space Launch System, the Hubble and Chandra observatories and others – including multiple SmallSat missions. Two SmallSat solar sail missions will be among those taking advantage of the HOSC’s resources for planning, training for and executing mission operations – the Near Earth Asteroid (NEA) Scout and Solar Cruiser missions. One of 10 6U CubeSats manifest on the Artemis I launch of NASA’s Space Launch System rocket this year, NEA Scout’s three-year mission will be supported through a more traditional operations concept, with a dedicated Flight Controller staff operating within the HOSC. Scheduled to launch as part of the Interstellar Mapping and Acceleration Probe (IMAP) in February 2025, Solar Cruiser’s 11-month mission will take a next[1]generation approach to operations by utilizing a multi-mission flight controller concept, as well as Marshall’s Telescience Resource Kit (TreK). TreK provides a suite of software applications and libraries that allow the Mission Operations Center to serve as an in-house ground system which incorporates remote and automation capability options for engineers and scientists. This presentation will compare the approaches the HOSC will use to support these two missions as a way of demonstrating the array of options NASA MSFC offers for operations support for CubeSat and SmallSat missions
Authentication Based on Periocular Biometrics and Skin Tone
Face images with masks have a major effect on the identification and authentication of people with masks covering key facial features such as noses and mouths. In this paper, we propose to use periocular region and skin tone for authenticating users with masked faces. We first extract the periocular region of faces with masks, then detect the skin tone for each face. We then train models using machine learning algorithms Random Forest, XGBoost, and Decision Trees using skin tone information and perform classification on two datasets. Experiment results show these models had good performance
The Between Story’: trauma fĂsico y psĂquico en la poesĂa de Sonia Sánchez y Lucille Clifton
Rhetorical choices used by Black women poets makes their work a militant force in the theoretical war against racist and sexist oppression. Research on trauma and testimony supports a breakdown of the person’s or character’s sudden brush with death –a moment that will never be fully realized, however it is at the center of explicating the rhetorical signs of trauma. Through a reading of Sonia Sanchez’s poems “Wounded in the House of a Friend” (Sanchez, 1995: 5), “Poem for Some Women” (Sanchez, 1995: 72), “Eyewitness: Case No. 3456” (Sanchez, 1995: 70), and “Poem at Thirty” (Sanchez, 1985: 4), with Lucille Clifton’s “My Friends” (Clifton, 1987: 147), “Shapeshifter Poems” (Clifton, 2000: 52), and “Song at Midnight” (Clifton, 1993: 24), my analysis will trace how traumatic wounding constitutes a psychic wound. It then applies the racialized and gendered reading of the subjects in the poem (insidious trauma), and how time and space relates to the subjects, space, and silences (traumatic realism). With the use trauma theory, I will illustrate how Sanchez and Clifton’s aesthetic forms adapted the militancy of the Black Arts Movement to address the silenced voices. In particular, the silenced voices of subjects continually subsumed beneath the phallocentric undertones challenged by Black feminist discourse, art, and poetry will be addressed.Las opciones retĂłricas utilizadas por las poetas negras hacen de su trabajo una herramienta militante en la batalla teĂłrica contra la opresiĂłn racista y sexista. Investigar sobre el trauma y el testimonio conlleva una crisis de la persona o el carácter, repentinamente teñidos con la muerte –un momento nunca por entero realizado–, que sin embargo está en el centro de la explicaciĂłn de los signos retĂłricos del trauma. Mediante la lectura de los poemas de Sonia Sánchez “Wounded in the House of a Friend” (Sanchez, 1995: 5), “Poem for Some Women” (Sanchez, 1995: 72), “Eyewitness: Case No. 3456” (Sanchez, 1995: 70) y “Poem at Thirty” (Sanchez, 1985: 4), asĂ como “My Friends” (Clifton, 1987: 147), “Shapeshifter Poems” (Clifton, 2000: 52) y “Song at Midnight” (Clifton, 1993: 24) de Lucille Clifton, muestra mi análisis cĂłmo la herida traumática conforma una herida psĂquica. Además aplica enfoques de raza y de gĂ©nero a la lectura de los sujetos del poema (el trauma insidioso), y a cĂłmo el tiempo y el espacio se relacionan con individuos, lugar y silencios (realismo traumático). Utilizando la teorĂa del trauma, quiero asĂ ilustrar cĂłmo las formas estĂ©ticas de S. Sánchez y L. Clifton adaptaron la militancia del Black Arts Movement al tratamiento de voces silenciadas. AbordarĂ© en particular las voces silenciadas de sujetos permanentemente sometidos a connotaciones falocĂ©ntricas, esas que son desafiadas por el discurso, el arte y la poesĂa del feminismo negro
Cognitive-Motor Interference During Functional Mobility After Stroke: State of the Science and Implications for Future Research
Cognitive-motor interference (CMI) is evident when simultaneous performance of a cognitive task and a motor task results in deterioration in performance in one or both of the tasks, relative to performance of each task separately. The purpose of this review is to present a framework for categorizing patterns of CMI and to examine the specific patterns of CMI evident in published studies comparing single-task and dual-task performance of cognitive and motor tasks during gait and balance activities after stroke. We also examine the literature for associations between patterns of CMI and history of falls, as well as evidence for the effects of rehabilitation on CMI after stroke. Overall, this review suggests that during gait activities with an added cognitive task, people with stroke are likely to demonstrate significant decrements in motor performance only (cognitive-related motor interference) or decrements in both motor and cognitive performance (mutual interference). In contrast, patterns of CMI were variable among studies examining balance activities. Comparing people post-stroke with and without a history of falls, patterns and magnitude of CMI were similar for fallers and non-fallers. Longitudinal studies suggest that conventional rehabilitation has minimal effects on CMI during gait or balance activities. However, early phase pilot studies suggest that dual-task interventions may reduce CMI during gait performance in community-dwelling stroke survivors. It is our hope that this innovative and critical examination of the existing literature will highlight the limitations in current experimental designs and inform improvements in the design and reporting of dual-task studies in stroke
Placental glucocorticoid receptor isoforms in a sheep model of maternal allergic asthma
Maternal asthma increases the risk of adverse pregnancy outcomes and may affect fetal growth and placental function by differential effects on the expression of glucocorticoid receptor (GR) isoforms, leading to altered glucocorticoid signalling. Our aim was to examine the effect of maternal asthma on placental GR profiles using a pregnant sheep model of asthma. Nine known GR isoforms were detected. There was a significant increase in the expression of placental GR isoforms that are known to have low trans-activational activity in other species including GR A, GR P and GRÎł which may result in a pro-inflammatory environment in the presence of allergic asthma
1953: Abilene Christian College Bible Lectures - Full Text
Delivered in the Auditorium of Abilene Christian College,
February, 1953
ABILENE, TEXAS
PRICE: $3.00
firm foundation publishing house
Box 77 Austin 01, Texa
Decoherence, the measurement problem, and interpretations of quantum mechanics
Environment-induced decoherence and superselection have been a subject of
intensive research over the past two decades, yet their implications for the
foundational problems of quantum mechanics, most notably the quantum
measurement problem, have remained a matter of great controversy. This paper is
intended to clarify key features of the decoherence program, including its more
recent results, and to investigate their application and consequences in the
context of the main interpretive approaches of quantum mechanics.Comment: 41 pages. Final published versio
A Sino-German 6cm polarization survey of the Galactic plane VII. Small supernova remnants
We study the spectral and polarization properties of supernova remnants
(SNRs) based on our 6cm survey data. The observations were taken from the
Sino-German 6cm polarization survey of the Galactic plane. By using the
integrated flux densities at 6cm together with measurements at other
wavelengths from the literature we derive the global spectra of 50 SNRs. In
addition, we use the observations at 6cm to present the polarization images of
24 SNRs. We derived integrated flux densities at 6cm for 51 small SNRs with
angular sizes less than 1 degree. Global radio spectral indices were obtained
in all the cases except for Cas A. For SNRs G15.1-1.6, G16.2-2.7, G16.4-0.5,
G17.4-2.3, G17.8-2.6, G20.4+0.1, G36.6+2.6, G43.9+1.6, G53.6-2.2, G55.7+3.4,
G59.8+1.2, G68.6-1.2, and G113.0+0.2, the spectra have been significantly
improved. From our analysis we argue that the object G16.8-1.1 is probably an
HII region instead of a SNR. Cas A shows a secular decrease in total intensity,
and we measured a flux density of 688+/-35 Jy at 6cm between 2004 and 2008.
Polarized emission from 25 SNRs were detected. For G16.2-2.7, G69.7+1.0,
G84.2-0.8 and G85.9-0.6, the polarized emission is detected for the first time
confirming them as SNRs. High frequency observations of SNRs are rare but
important to establish their spectra and trace them in polarization in
particular towards the inner Galaxy where Faraday effects are important.Comment: 14 pages, 4 figures, 2 tables, accepted for publication in A&
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