4,465 research outputs found

    Marshall Space Flight Center Faculty Fellowship Program

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    The 2017 Marshall Faculty Fellowship Program involved 21 faculty in the laboratories and departments at Marshall Space Flight Center. These faculty engineers and scientists worked with NASA collaborators on NASA projects, bringing new perspectives and solutions to bear. This Technical Memorandum is a compilation of the research reports of the 2017 Marshall Faculty Fellowship program, along with the Program Announcement (Appendix A) and the Program Description (Appendix B). The research affected the following six areas: (1) Materials (2) Propulsion (3) Instrumentation (4) Spacecraft systems (5) Vehicle systems (6) Space science The materials investigations included composite structures, printing electronic circuits, degradation of materials by energetic particles, friction stir welding, Martian and Lunar regolith for in-situ construction, and polymers for additive manufacturing. Propulsion studies were completed on electric sails and low-power arcjets for use with green propellants. Instrumentation research involved heat pipes, neutrino detectors, and remote sensing. Spacecraft systems research was conducted on wireless technologies, layered pressure vessels, and two-phase flow. Vehicle systems studies were performed on life support-biofilm buildup and landing systems. In the space science area, the excitation of electromagnetic ion-cyclotron waves observed by the Magnetospheric Multiscale Mission provided insight regarding the propagation of these waves. Our goal is to continue the Marshall Faculty Fellowship Program funded by Center internal project offices. Faculty Fellows in this 2017 program represented the following minority-serving institutions: Alabama A&M University and Oglala Lakota College

    Extending the Outreach : From Smart Cities to Connected Communities

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    Connected Communities (CCs) are socio-technical systems that rely on an information and communication technology (ICT) infrastructure to integrate people and organizations (companies, schools, hospitals, universities, local and national government agencies) willing to share information and perform joint decision-making to create sustainable and equitable work and living environments. We discuss a research agenda considering CCs from three distinct but complementary points of view: CC metaphors, models, and services

    No surviving companion in Kepler's supernova

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    We have surveyed Kepler's supernova remnant in search of the companion star of the explosion. We have gone as deep as 2.6 solar luminosities in the stars within 20% of the radius of the remnant. We use FLAMES at the VLT-UT2 telescope to obtain high resolution spectra of the stellar candidates selected from HST images. The resulting set of stellar parameters suggests that these stars come from a rather ordinary mixture of field stars (mostly giants). A few of the stars seem to have low [Fe/H] (< -1) and they are consistent with being metal-poor giants. The radial velocities and rotational velocities vrot sin i are very well determined. There are no fast rotating stars as vrot sin i < 20 km/s. The radial velocities from the spectra and the proper motions determined from HST images are compatible with those expected from the Besan\c{c}on model of the Galaxy. The strong limits placed on luminosity suggest that this supernova could have arisen either from the core-degenerate scenario or from the double-degenerate scenario.Comment: ApJ accepted, 7 figures and 7 table

    Writing Strength-based IEPs for Students with Disabilities in Inclusive Classrooms

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    Throughout this practitioner-oriented paper, we provide a rationale, framework, and supporting materials to promote the development and implementation of personalized, contextualized, and holistic individualized education plans (IEPs) with a strength-based orientation. We believe that adopting strength-based IEP writing practices is vital to reconstructing students with disabilities as capable contributors to their inclusive classrooms. The use of strengths-based approaches is not necessarily new, however supporting individuals’ needs in a strength-based model has been largely overlooked in special education. Despite their growing application, inclusive pedagogical approaches are largely absent in the development of strength-based IEPs for students with disabilities. IEPs remain largely deficit-focused with only surface level attention given to documenting students’ strengths and abilities. When present levels academic performance statements and IEP goals are written in a deficit-oriented manner, special educators miss opportunities to see beyond the limitations and challenges that their students may face, and instead, overly focus on the shortcomings of the student. However, by adopting a strength-based approach, special educators can instead focus their attention on remediating these deficits by paying attention to the student as an individual and highlight their students’ many strengths and capabilities

    Computation Against a Neighbour: Addressing Large-Scale Distribution and Adaptivity with Functional Programming and Scala

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    Recent works in contexts like the Internet of Things (IoT) and large-scale Cyber-Physical Systems (CPS) propose the idea of programming distributed systems by focussing on their global behaviour across space and time. In this view, a potentially vast and heterogeneous set of devices is considered as an “aggregate” to be programmed as a whole, while abstracting away the details of individual behaviour and exchange of messages, which are expressed declaratively. One such a paradigm, known as aggregate programming, builds on computational models inspired by field-based coordination. Existing models such as the field calculus capture interaction with neighbours by a so-called “neighbouring field” (a map from neighbours to values). This requires ad-hoc mechanisms to smoothly compose with standard values, thus complicating programming and introducing clutter in aggregate programs, libraries and domain-specific languages (DSLs). To address this key issue we introduce the novel notion of “computation against a neighbour”, whereby the evaluation of certain subexpressions of the aggregate program are affected by recent corresponding evaluations in neighbours. We capture this notion in the neighbours calculus (NC), a new field calculus variant which is shown to smoothly support declarative specification of interaction with neighbours, and correspondingly facilitate the embedding of field computations as internal DSLs in common general-purpose programming languages—as exemplified by a Scala implementation, called ScaFi. This paper formalises NC, thoroughly compares it with respect to the classic field calculus, and shows its expressiveness by means of a case study in edge computing, developed in ScaFi

    A taxonomic note concerning a dicynodont (Synapsida: Anomodontia) from the Middle Triassic of East Africa

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    Main articleThe complicated histories of the Indian dicynodont Rechnisaurus and the East African dicynodont Kannemeyeria cristarhynchus has led to the incorrect use of the name ‘cristarhynchus’ for the latter taxon. This paper therefore proposes a new species name and diagnosis.The National Research Foundation and University Research Committee of the University of the Witwatersran

    From security to assurance in the cloud: a survey

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    The cloud computing paradigm has become a mainstream solution for the deployment of business processes and applications. In the public cloud vision, infrastructure, platform, and software services are provisioned to tenants (i.e., customers and service providers) on a pay-as-you-go basis. Cloud tenants can use cloud resources at lower prices, and higher performance and flexibility, than traditional on-premises resources, without having to care about infrastructure management. Still, cloud tenants remain concerned with the cloud's level of service and the nonfunctional properties their applications can count on. In the last few years, the research community has been focusing on the nonfunctional aspects of the cloud paradigm, among which cloud security stands out. Several approaches to security have been described and summarized in general surveys on cloud security techniques. The survey in this article focuses on the interface between cloud security and cloud security assurance. First, we provide an overview of the state of the art on cloud security. Then, we introduce the notion of cloud security assurance and analyze its growing impact on cloud security approaches. Finally, we present some recommendations for the development of next-generation cloud security and assurance solutions

    Gaia-ESO Survey: Gas dynamics in the Carina nebula through optical emission lines

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    Aims. We present observations from the Gaia-ESO Survey in the lines of Hα, [N II], [S II], and He I of nebular emission in the central part of the Carina nebula. Methods. We investigate the properties of the two already known kinematic components (approaching and receding), which account for the bulk of emission. Moreover, we investigate the features of the much less known low-intensity high-velocity (absolute RV >50 km s) gas emission. Results. We show that gas giving rise to Hα and He I emission is dynamically well correlated with but not identical to gas seen through forbidden-line emission. Gas temperatures are derived from line-width ratios, and densities from [S II] doublet ratios. The spatial variation of N ionization is also studied, and found to differ between the approaching and receding components. The main result is that the bulk of the emission lines in the central part of Carina arise from several distinct shell-like expanding regions, the most evident found around η Car, the Trumpler 14 core, and the star WR25. These >shells> are non-spherical and show distortions probably caused by collisions with other shells or colder, higher-density gas. Some of them are also partially obscured by foreground dust lanes, while very little dust is found in their interior. Preferential directions, parallel to the dark dust lanes, are found in the shell geometries and physical properties, probably related to strong density gradients in the studied region. We also find evidence that the ionizing flux emerging from η Car and the surrounding Homunculus nebula varies with polar angle. The high-velocity components in the wings of Hα are found to arise from expanding dust reflecting the η Car spectrum. © ESO, 2016.This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541Peer Reviewe
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