2,001 research outputs found

    Intact capture of hypervelocity particles

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    Knowledge of the phase, structure, and crystallography of cosmic particles, as well as their elemental and isotopic compositions, would be very valuable information toward understanding the nature of our solar system. This information can be obtained from the intact capture of large mineral grains of cosmic particles from hypervelocity impacts. Hypervelocity experiments of intact capture in underdense media have indicated realistic potential in this endeaver. The recovery of the thermal blankets and louvers from the Solar Max spacecraft have independently verified this potential in the unintended capture of cosmic materials from hypervelocity impacts. Passive underdense media will permit relatively simple and inexpensive missions to capture cosmic particles intact, either by going to a planetary body or by waiting for the particles to come to the Shuttle or the Space Station. Experiments to explore the potential of using various underdense media for an intact comet sample capture up to 6.7 km/s were performed at NASA Ames Research Center Vertical Gun Range. Explorative hypervelocity experiments up to 7.9 km/s were also made at the Ernst Mach Institute. These experiments have proven that capturing intact particles at hypervelocity impacts is definitely possible. Further research is being conducted to achieve higher capture ratios at even higher hypervelocities for even smaller projectiles

    Pre-Congestion Notification (PCN) Architecture

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    This document describes a general architecture for flow admission and termination based on pre-congestion information in order to protect the quality of service of established, inelastic flows within a single Diffserv domain.\u

    Theme and Variation: The Survey of MLA Personnel Characteristics

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    Presentation at annual national meeting of the Music Library Association, San Diego, CA, March 201

    Noncausal telemetry data recovery techniques

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    Cost efficiency is becoming a major driver in future space missions. Because of the constraints on total cost, including design, implementation, and operation, future spacecraft are limited in terms of their size power and complexity. Consequently, it is expected that future missions will operate on marginal space-to-ground communication links that, in turn, can pose an additional risk on the successful scientific data return of these missions. For low data-rate and low downlink-margin missions, the buffering of the telemetry signal for further signal processing to improve data return is a possible strategy; it has been adopted for the Galileo S-band mission. This article describes techniques used for postprocessing of buffered telemetry signal segments (called gaps) to recover data lost during acquisition and resynchronization. Two methods, one for a closed-loop and the other one for an open-loop configuration, are discussed in this article. Both of them can be used in either forward or backward processing of signal segments, depending on where a gap is specifically situated in a pass

    Emotions in Deaf and Hard-of-Hearing and Typically Hearing Children

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    For deaf and hard-of-hearing (DHH) children living in an environment where their access to linguistic input and social interactions is compromised, learning emotions could be difficult, which may further affect social functioning. To understand the role of emotion in DHH children’s social life, this study investigated emotional functioning (i.e., emotion recognition, empathy, emotion expression), and its relation with social functioning (i.e., social competence and externalizing behaviors), in 55 DHH children and 74 children with typical hearing (aged 3–10 years; M_{age} = 6.04). Parental reports on children’s emotional and social functioning and factors related to DHH children’s hearing were collected. Results showed similar levels of emotional and social functioning in children with and without hearing loss. Use of auditory intervention and speech perception did not correlate with any measures in DHH children. In both groups, higher levels of empathy related to higher social competence and fewer externalizing behaviors; emotion recognition and positive emotion expression were unrelated to either aspect of social functioning. Higher levels of negative emotion expression related to lower social competence in both groups, but to more externalizing behaviors in DHH children only. DHH children in less linguistically accessible environments may not have adequate knowledge for appropriately expressing negative emotions socially

    Therapeutic and educational objectives in robot assisted play for children with autism

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.” DOI: 10.1109/ROMAN.2009.5326251This article is a methodological paper that describes the therapeutic and educational objectives that were identified during the design process of a robot aimed at robot assisted play. The work described in this paper is part of the IROMEC project (Interactive Robotic Social Mediators as Companions) that recognizes the important role of play in child development and targets children who are prevented from or inhibited in playing. The project investigates the role of an interactive, autonomous robotic toy in therapy and education for children with special needs. This paper specifically addresses the therapeutic and educational objectives related to children with autism. In recent years, robots have already been used to teach basic social interaction skills to children with autism. The added value of the IROMEC robot is that play scenarios have been developed taking children's specific strengths and needs into consideration and covering a wide range of objectives in children's development areas (sensory, communicational and interaction, motor, cognitive and social and emotional). The paper describes children's developmental areas and illustrates how different experiences and interactions with the IROMEC robot are designed to target objectives in these areas.Final Published versio

    Precision Pointing Control System (PPCS) system design and analysis

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    The precision pointing control system (PPCS) is an integrated system for precision attitude determination and orientation of gimbaled experiment platforms. The PPCS concept configures the system to perform orientation of up to six independent gimbaled experiment platforms to design goal accuracy of 0.001 degrees, and to operate in conjunction with a three-axis stabilized earth-oriented spacecraft in orbits ranging from low altitude (200-2500 n.m., sun synchronous) to 24 hour geosynchronous, with a design goal life of 3 to 5 years. The system comprises two complementary functions: (1) attitude determination where the attitude of a defined set of body-fixed reference axes is determined relative to a known set of reference axes fixed in inertial space; and (2) pointing control where gimbal orientation is controlled, open-loop (without use of payload error/feedback) with respect to a defined set of body-fixed reference axes to produce pointing to a desired target

    Inhibition of EZH2 Ameliorates LupusĂą Like Disease in MRL/lpr Mice

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151823/1/art40931_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151823/2/art40931.pd
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