3,885 research outputs found

    Data-handling considerations for advanced high-resolution multispectral scanners

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    Several scanner design parameters that greatly affect data rates were varied to determine overall effect on data rates. Bit rates were calculated for scanners with 10-, 15-, 20-, and 30-meter instantaneous fields of view; with 5, 7, and 10 channels; and with swath widths of 46.3, 92.6, 138.9, and 185.2 kilometers (25, 50, 75, and 100 nautical miles). The data were analyzed to determine whether they could be (1) recorded onboard the spacecraft with currently available equipment, (2) recorded onboard with the equipment proposed for the 1980-90 period, (3) transmitted to earth with current or proposed equipment; and (4) compressed and decompressed without significant degradation of classification accuracy. The effect of classifying 10-meter scanner data on the existing and the development pattern-recognition systems was examined

    A procedure for automated land use mapping using remotely sensed multispectral scanner data

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    A system of processing remotely sensed multispectral scanner data by computer programs to produce color-coded land use maps for large areas is described. The procedure is explained, the software and the hardware are described, and an analogous example of the procedure is presented. Detailed descriptions of the multispectral scanners currently in use are provided together with a summary of the background of current land use mapping techniques. The data analysis system used in the procedure and the pattern recognition software used are functionally described. Current efforts by the NASA Earth Resources Laboratory to evaluate operationally a less complex and less costly system are discussed in a separate section

    Effects of Backward Walking on Hamstring Flexibility and Low Back Range of Motion

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    The purpose of the study was to examine the effects of backward walking on hamstring flexibility and low back range of motion. Ten healthy female volunteers (29.9±10.0 yr; 165.1±8.2 cm; 68.53±18.4 kg) completed pre-post laboratory testing surrounding a 4-week intervention of backward walking. During the pretest, each participant walked forward on a treadmill at a preferred velocity for 3-5 min. A biaxial electrogoniometer was secured externally to the low back and a sit-and-reach test was performed. Each participant then walked backward at their preferred pace on a treadmill for 10 min, during which time low back motion data were obtained (1000 Hz). Following the pretest, participants completed an intervention of walking backward at a self-selected velocity for 10-15 min/day, 4 days/week. This was followed by a posttest, using the exact protocol as the pretest. Dependent variables consisted of pre-post measures of: 1) backward walking velocity (VEL), 2) flexibility of the hamstrings (HF), low back sagittal plane range of motion (sROM), and low back coronal plane range of motion (cROM). Correlated t-tests (α = 0.05) with Bonferroni correction identified significant (p \u3c 0.001) differences in VEL and HF. Low back motion parameters (sROM, cROM) were not significantly different (p \u3e 0.0125) following the intervention. Results of the study suggest that a 4-week intervention of backward walking appears to provide an appropriate stimulus for an increase in flexibility of the hamstrings. A possible interaction between VEL and sROM or cROM limited the interpretation of observed non-significant changes in low back motion

    Business education and the (re)production of gendered cultures of work in the City of London

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    This paper examines the role of business education in producing and legitimating gendered cultures of work in the City of London. By combining research on the gendered nature of service work with Bourdieu's identification of multiple forms of capital and the role of education credentials within this, the analysis shows how business education reproduces classed and gendered understandings of appropriate and desirable workplace personas in financial services. The analysis is based on original empirical research undertaken in London's investment banking sector comprising 90 semi-structured interviews and content analysis of business education courses offered to investment bankers. Empirically, the paper focuses attention on the comparatively neglected role of business education undertaken in the workplace in shaping the cultures of work in financial centers such as London. Theoretically, the analysis shows how work on the cultural capital associated with education credentials and their role in shaping workplace identities can be used to better understand the role of education in legitimating, reproducing and sustaining gendered cultures of work more generally

    Mechanical Properties of T650-35/AFR-PE-4 at Elevated Temperatures for Lightweight Aeroshell Designs

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    Considerable efforts have been underway to develop multidisciplinary technologies for aeroshell structures that will significantly increase the allowable working temperature for the aeroshell components, and enable the system to operate at higher temperatures while sustaining performance and durability. As part of these efforts, high temperature polymer matrix composites and fabrication technologies are being developed for the primary load bearing structure (heat shield) of the spacecraft. New high-temperature resins and composite material manufacturing techniques are available that have the potential to significantly improve current aeroshell design. In order to qualify a polymer matrix composite (PMC) material as a candidate aeroshell structural material, its performance must be evaluated under realistic environments. Thus, verification testing of lightweight PMC's at aeroshell entry temperatures is needed to ensure that they will perform successfully in high-temperature environments. Towards this end, a test program was developed to characterize the mechanical properties of two candidate material systems, T650-35/AFR-PE-4 and T650-35/RP46. The two candidate high-temperature polyimide resins, AFR-PE-4 and RP46, were developed at the Air Force Research Laboratory and NASA Langley Research Center, respectively. This paper presents experimental methods, strength, and stiffness data of the T650-35/AFR-PE-4 material as a function of elevated temperatures. The properties determined during the research test program herein, included tensile strength, tensile stiffness, Poisson s ratio, compressive strength, compressive stiffness, shear modulus, and shear strength. Unidirectional laminates, a cross-ply laminate and two eight-harness satin (8HS)-weave laminates (4-ply and 10-ply) were tested according to ASTM standard methods at room and elevated temperatures (23, 316, and 343 C). All of the relevant test methods and data reduction schemes are outlined along with mechanical data. These data contribute to a database of material properties for high-temperature polyimide composites that will be used to identify the material characteristics of potential candidate materials for aeroshell structure applications

    Using LibGuides to Promote Faculty/Librarian Interaction

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    Radon exposure and cancers other than lung cancer in Swedish iron miners.

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    Data are presented on the risks of cancers other than lung cancer in a cohort of iron miners from northern Sweden occupationally exposed to elevated levels of the radioactive gas radon. Compared with rates for the four northernmost counties of Sweden, mortality was increased for all cancers other than lung cancer (ratio of observed to expected deaths 1.21, 95% confidence interval 1.03-1.41), stomach cancer (ratio of observed to expected deaths 1.45, 95% confidence interval 1.04-1.98), and rectal cancer (ratio of observed to expected deaths 1.94, 95% confidence interval 1.03-3.31). Despite these overall increases, mortality was not significantly associated with cumulative exposure to radon, either for all cancers other than lung cancer or for any site of cancer other than lung cancer individually. However, the data from this cohort on its own have limited power; and for several sites of cancer the data in this study would be consistent with a radon-related increase. Further study of cancers other than lung cancer in populations exposed to radon is required

    Ultra-Wideband Communication and Sensor Fusion Platform for the Purpose of Multi-Perspective Localization.

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    Localization is a keystone for a robot to work within its environment and with other robots. There have been many methods used to solve this problem. This paper deals with the use of beacon-based localization to answer the research question: Can ultra-wideband technology be used to effectively localize a robot with sensor fusion? This paper has developed an innovative solution for creating a sensor fusion platform that uses ultra-wideband communication as a localization method to allow an environment to be perceived and inspected in three dimensions from multiple perspectives simultaneously. A series of contributions have been presented, supported by an in-depth literature review regarding topics in this field of knowledge. The proposed method was then designed, built, and tested successfully in two different environments exceeding its required tolerances. The result of the testing and the ideas formulated throughout the paper were discussed and future work outlined on how to build upon this work in potential academic papers and projects

    Assessment of Technologies for the Space Shuttle External Tank Thermal Protection System and Recommendations for Technology Improvement - Part III: Material Property Characterization, Analysis, and Test Methods

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    The objective of this report is to contribute to the independent assessment of the Space Shuttle External Tank Foam Material. This report specifically addresses material modeling, characterization testing, data reduction methods, and data pedigree. A brief description of the External Tank foam materials, locations, and standard failure modes is provided to develop suitable background information. A review of mechanics based analysis methods from the open literature is used to provide an assessment of the state-of-the-art in material modeling of closed cell foams. Further, this report assesses the existing material property database and investigates sources of material property variability. The report presents identified deficiencies in testing methods and procedures, recommendations for additional testing as required, identification of near-term improvements that should be pursued, and long-term capabilities or enhancements that should be developed
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