3,040 research outputs found

    A method for interference mitigation in space communications scheduling

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    Increases in the number of user spacecraft and data rates supported by NASA's Tracking and Data Relay Satellite System (TDRSS) in the S and Ku bands could result in communications conflicts due to mutual interference. A method to mitigate interference while minimizing unnecessary scheduling restrictions on both TDRSS network and user resources, based on consideration of all relevant communications parameters, was developed. The steps of this method calculate required separation angles at TDRS and produce interference intervals, which can be used in the production of schedules free of unacceptable interference. The method can also be used as a basis for analysis, evaluation, and optimization of user schedules with respect to communications performance. Described here are the proposed method and its potential application to scheduling in space communications. Test cases relative to planned missions, including the Earth Observing System, the Space Station Manned Base, and the Space Shuttle are discussed

    Linguistic Politeness and Greeting Rituals in German-speaking Switzerland

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    This paper describes the results of research into linguistic politeness in German-speaking Switzerland (GSS) and into one type of politeness in particular, namely the speech acts of greeting and leave-taking denoted by the German verb grüssen.[1] German-speaking Swiss people adhere to strict conventions of polite behaviour which have been eroded over time in the English-speaking world. My research shows that speakers of Swiss German, both young and old, and from all walks of life, believe that it is important to retain their traditional politeness rituals, and that greetings formulae are especially important. Very few germanophone Swiss that people conform to polite greeting practices out of self-interest (as one of my informants suggested), rather they believe that politeness is important for social cohesion and a sign of respect and affection for one's fellow human beings

    On Attending College and Living at Home

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    Non-fiction by Sherry A. Rash

    Social Support in Elderly Nursing Home Populations: Manifestations and Influences

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    The purpose of this study was to describe the characteristics of social support and the influencing factors on social support in nursing home environments. Observations and staff questionnaires from two central Florida nursing homes were used in this grounded theory study to answer the following questions: (1) How is social support manifested? and (2) What are influences on social support? Social support manifestations seemed predominantly superficial and did not appear to involve complex reciprocal relationships, however, when reciprocal resident tasks were observed, they appeared to have significant value and were sources of pride for the residents. Facility behaviors and policies required by governmental mandates appeared to result in significant resident dependency, a situation that mitigates against significant social support

    An RF interference mitigation methodology with potential applications in scheduling

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    Software tools for interference analysis and mitigation were developed in the Communications Link Analysis and Simulation System (CLASS) environment for: communications performance evaluation; and mission planning. Potential applications are seen in analysis, evaluation, and optimization of user schedules. Tools producing required separation angles and potential interference intervals can be used as an aid to mutual interference mitigation within a scheduling system

    Reliability study of the NiH2 strain gage

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    This paper summarizes a joint study by Gates Aerospace Batteries (GAB) and the Reliability Analysis Center (RAC). This study characterizes the reliability and robustness of the temperature compensated strain gages currently specified for sensing of internal pressure of NiH2 cells. These strain gages are characterized as fully encapsulated, metallic foil grids with known resistance that varies with deformation. The measurable deformation, when typically installed on the hemispherical portion of a NiH2 cell, is proportional to the material stresses as generated by internal cell pressures. The internal pressure sensed in this manner is calibrated to indicate the state-of-charge for the cell. This study analyzes and assesses both robustness and reliability for the basic design of the strain gage, the installation of the strain gage, and the circuitry involved

    The impact of a vaginal brachytherapy boost to pelvic radiation in stage III endometrial cancer.

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    PURPOSE:We investigate the use and impact of a vaginal brachytherapy boost (VBB) after pelvic radiotherapy for stage III endometrial adenocarcinoma on vaginal and pelvic control. MATERIAL AND METHODS:One hundred patients treated from 1998-2011 with surgery and adjuvant therapy with or without a VBB were included. Variables examined were grade, stage, lymphovascular space invasion (LVSI), vaginal involvement (VI), cervical stromal involvement (CSI), myometrial invasion (MI), and a VBB. Failure was scored as vaginal, or pelvic. Fisher's exact test assessed association between variables with vaginal and pelvic control. RESULTS:With a median follow up of 43 months, 31% were stage IIIA, 6% stage IIIB, and 63% stage IIIC. Thirty-eight (38%) received pelvic radiotherapy alone, and 62% received adjuvant chemotherapy. Of the 100 patients, 82 were treated with a VBB, 10 were not treated with a VBB, and 8 were not treated with RT. Of the 82 patients who received a VBB, 5 failed in the vagina with vaginal and pelvic control rates of 94% and 92%. The impact of VB reached borderline significance with its impact on pelvic control, 92% vs. 70% (p = 0.056), and did not affect vaginal control, 94% and 90% (p = 0.50). Neither tumor grade, LVSI, CSI, stage, nor LVSI (p > 0.05) statistically significantly impacted vaginal control. CONCLUSIONS:There are no clinical guidelines for the use of a VBB in stage III endometrial cancer. The majority of our patients were treated with a VBB and experienced excellent pelvic and vaginal control. The presence of traditional adverse features did not negatively impact control in our patient cohort. However, the role of a VBB needs further investigation to understand the incremental benefit beyond pelvic RT

    Growth, Condition, and Trophic Relations of Stocked Trout in Southern Appalachian Mountain Streams

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    Stream trout fisheries are among the most popular and valuable in the United States, but many are dependent on hatcheries to sustain fishing and harvest. Thus, understanding the ecology of hatchery‐reared trout stocked in natural environments is fundamental to management. We evaluated the growth, condition, and trophic relations of Brook Trout Salvelinus fontinalis, Brown Trout Salmo trutta, and Rainbow Trout Oncorhynchus mykiss that were stocked in southern Appalachian Mountain streams in western North Carolina. Stocked and wild (naturalized) trout were sampled over time (monthly; September 2012–June 2013) to compare condition and diet composition and to evaluate temporal dynamics of trophic position with stable isotope analysis. Relative weights (Wr) of stocked trout were inversely associated with their stream residence time but were consistently higher than those of wild trout. Weight loss of harvested stocked trout was similar among species and sizes, but fish stocked earlier lost more weight. Overall, 40% of 141 stomachs from stocked trout were empty compared to 15% of wild trout stomachs (N = 26). We identified a much higher rate of piscivory in wild trout (18 times that of stocked trout), and wild trout were 4.3 times more likely to consume gastropods relative to stocked trout. Hatchery‐reared trout were isotopically similar to co‐occurring wild fish for both δ13C and δ15N values but were less variable than wild trout. Differences in sulfur isotope ratios (δ34S) between wild and hatchery‐reared trout indicated that the diets of wild fish were enriched in δ34S relative to the diets of hatchery‐reared fish. Although hatcheryreared trout consumed prey items similar to those of wild fish, differences in consumption or behavior (e.g., reduced feeding) may have resulted in lower condition and negative growth. These findings provide critical insight on the trophic dynamics of stocked trout and may assist in developing and enhancing stream trout fisheries
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