6,192 research outputs found

    Criteria for vibration testing

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    Systematic application of response spectral analysis and other analyses determine damping sensitivity of flight environment and candidate laboratory tests. Computerized comparison is made between response spectrum for flight environment, or enveloping spectra for collection of flight events, and response spectrum for candidate laboratory test

    Self-Paced Endurance Performance and Cerebral Hemodynamics of the Prefrontal Cortex: A Scoping Review of Methodology and Findings.

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    Recent research has suggested that top-down executive function associated with the prefrontal cortex is key to the decision-making processes and pacing of endurance performance. A small but growing body of literature has investigated the neurological underpinnings of these processes by subjecting the prefrontal cortex to functional near-infrared spectroscopy (fNIRS) measurement during self-paced endurance task performance. Given that fNIRS measurement for these purposes is a relatively recent development, the principal aim of this review was to assess the methodological rigor and findings of this body of research. We performed a systematic literature search to collate research assessing prefrontal cortex oxygenation via fNIRS during self-paced endurance performance. A total of 17 studies met the criteria for inclusion. We then extracted information concerning the methodology and findings from the studies reviewed. Promisingly, most of the reviewed studies reported having adopted commonplace and feasible best practice guidelines. However, a lack of adherence to these guidelines was evident in some areas. For instance, there was little evidence of measures to tackle and remove artifacts from data. Lastly, the reviewed studies provide insight into the significance of cerebral oxygenation to endurance performance and the role of the prefrontal cortex in pacing behavior. Therefore, future research that better follows the guidelines presented will help advance our understanding of the role of the brain in endurance performance and aid in the development of techniques to improve or maintain prefrontal cortex (PFC) oxygenation to help bolster endurance performance

    The Gulf Stream Dynamics Experiment: Inverted Echo Sounder Data Report for the June 1984 to May 1985 Deployment Period

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    The Gulf Stream Dynamics Experiment was conducted in the region just northeast of Cape Hatteras from April 1983 to May 1985 to study the propagation and growth characteristics of Gulf Stream meanders. Data collected as part of the field experiment included inverted echo sounders, current meter moorings, and AXBT survey flights. This report documents the inverted echo sounder data collected from June 1984 to May 1985. Time series plots of the half-hourly travel time and low-pass filtered thermocline depth measurements are presented for eighteen instruments. Bottom pressure and temperature, measured at four of the sites, are also plotted. Basic statistics are given for all the data records shown. Maps of the thermocline depth field in a 240 km by 460 km region are presented at daily intervals

    The Gulf Stream Dynamics Experiment: Inverted Echo Sounder Data Report for the May 1985 to June 1986 Deployment Periond

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    The continuation of the Gulf Stream Dynamics Experiment was conducted at 70oW, about 450 km northeast of Cape Hatteras, to study the baroclinic transport and cross-stream thermocline structure of the Gulf Stream. This report documents the inverted echo sounder data collected during the May 1985 to June 1986 deployment period. Time series plots of the half-hourly travel time and low-pass filtered thermocline depth measurements are presented for ten instruments. Bottom pressure and temperature, measured at three sites, are also plotted. Basic statistics are given for all the data records shown. Maps of the thermocline depth field in a 120 km by 260 km box region are presented at daily intervals

    The new HiVIS spectropolarimeter and spectropolarimetric calibration of the AEOS telescope

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    We designed, built, and calibrated a new spectropolarimeter for the HiVIS spectrograph (R 12000-49000) on the AEOS telescope. We also did a polarization calibration of the telescope and instrument. We will introduce the design and use of the spectropolarimeter as well as a new data reduction package we have developed, then discuss the polarization calibration of the spectropolarimeter and the AEOS telescope. We used observations of unpolarized standard stars at many pointings to measure the telescope induced polarization and compare it with a Zemax model. The telescope induces polarization of 1-6% with a strong variation with wavelength and pointing, consistent with the altitude and azimuth variation expected. We then used scattered sunlight as a linearly polarized source to measure the telescopes spectropolarimetric response to linearly polarized light. We then made an all-sky map of the telescope's polarization response to calibrate future spectropolarimetry.Comment: PASP 118, June 200

    The influence of self-citation corrections on Egghe's g index

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    The g index was introduced by Leo Egghe as an improvement of Hirsch's index h for measuring the overall citation record of a set of articles. It better takes into account the highly skewed frequency distribution of citations than the h index. I propose to sharpen this g index by excluding the self-citations. I have worked out nine practical cases in physics and compare the h and g values with and without self-citations. As expected, the g index characterizes the data set better than the h index. The influence of the self-citations appears to be more significant for the g index than for the h index.Comment: 9 pages, 2 figures, submitted to Scientometric

    Recent results in the decoding of Algebraic geometry codes

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    Objectives: The aim of this study was to examine the relationships between perceived teacher autonomy support versus control and students’ life skills development in PE, and whether students’ basic need satisfaction and frustration mediated these relationships. Design: Cross-sectional study. Method: English and Irish students (N = 407, Mage = 13.71, SD = 1.23) completed measures assessing perceived autonomy-supportive and controlling teaching, basic need satisfaction and frustration (autonomy, competence, and relatedness), and life skills development in PE (teamwork, goal setting, social skills, problem solving and decision making, emotional skills, leadership, time management, and interpersonal communication). Results: On the bright side of Self-Determination Theory (SDT), correlations revealed that perceived teacher autonomy support was positively associated with students’ basic need satisfaction and life skills development in PE. On the dark side of SDT, perceived controlling teaching was positively related to students’ basic need frustration, but not significantly related to their life skills development. Mediational analyses revealed that autonomy and relatedness satisfaction mediated the relationships between perceived teacher autonomy support and students’ development of all eight life skills. Competence satisfaction mediated the relationships between perceived teacher autonomy support and students’ development of teamwork, goal setting, and leadership skills. Conclusions: Our findings indicate that satisfaction of the needs for autonomy, competence, and relatedness are important mechanisms that in part explain the relationships between perceived teacher autonomy support and life skills development in PE. Therefore, teachers may look to promote students’ perceptions of an autonomy-supportive climate that satisfies their three basic needs and helps to develop their life skills

    Data quality in the human and environmental health sciences: Using statistical confidence scoring to improve QSAR/QSPR modeling

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    A greater number of toxicity data are becoming publicly available allowing for in silico modeling. However, questions often arise as how to incorporate data quality and how to deal with contradicting data if more than a single datum point is available for the same compound. In this study, two well-known and studied QSAR/QSPR models for skin permeability and aquatic toxicology have been investigated in the context of statistical data quality. In particular, the potential benefits of the incorporation of the statistical Confidence Scoring (CS) approach within modelling and validation. As a result, robust QSAR/QSPR models for the skin permeability coefficient and the toxicity of nonpolar narcotics to Aliivibrio fischeri assay were created. CSweighted linear regression for training and CS-weighted root mean square error (RMSE) for validation were statistically superior compared to standard linear regression and standard RMSE. Strategies are proposed as to how to interpret data with high and low CS, as well as how to deal with large datasets containing multiple entries
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