11,405 research outputs found

    Certain summation and transformation formulas for generalized hypergeometric series

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    AbstractWe derive summation formulas for generalized hypergeometric series of unit argument, one of which upon specialization reduces to Minton’s summation theorem. As an application we deduce a reduction formula for a certain KampĂ© de FĂ©riet function that in turn provides a Kummer-type transformation formula for the generalized hypergeometric function pFp(x)

    Incomplete Lipschitz-Hankel integrals of Bessel functions

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    Minuteman III Cost Per Alert Hour Analysis

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    This thesis analyzes the cost associated with the Minuteman III (MM III) weapon system. The research develops three models for determining MM III costs per alert hour (CPAH). The first model is based on the Air Force Cost Analysis Improvement Group cost per flying hour model. The model is modified to include depot level reparables, consumables, and personnel costs. The second model is based on the Office of the Secretary of Defense, Cost Analysis Improvement Group cost per flying hour model and is formulated using service-wide data from the Air Force Total Ownership Cost tool. The third model is a comprehensive model including indirect costs associated the ICBM-supporting installations. Additionally, this thesis includes a CPAH for each echelon or level of management for the MM III. The data reveals a relatively small marginal CPAH at the lowest levels. However, due to the robust support structure for the MM III, the models reveal significant fixed alert-hour costs. Finally, the thesis discusses the workings of the MM III cost structure that may benefit future budgeting decisions. Specifically, the step functions associated with each level of management and the large fixed costs. This thesis presents the three models as a starting point for developing a CPAH predictive model in future research

    The Influence of Education and Experience upon Contextual and Task Performance in Warehouse Operations

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    Supply chain workers make observable, preventable errors while completing their assigned tasks in the shipping process. Previous research has indicated that individuals with a greater grasp of their work and better system knowledge are less likely to commit interpretation errors. We believe worker-performance may, likewise, be affected by an individuals knowledge of why and where they fit into a larger system defined as mission knowledge. To assess our research objectives, we conduct a controlled experiment with 100 workers in the Air Force supply career field to discern how mission clarity, that is, education, experience and subject characteristics affect pick and pack errors in simulated warehouse order fulfillment tasks. Results indicate that participants who received the experience treatment committed fewer errors, resulting in increased task performance

    Transcobalamin C776G genotype modifies the association between vitamin B12 and homocysteine in older Hispanics.

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    Background/objectivesA common polymorphism, C776G, in the plasma B12 transport protein transcobalamin (TC), encodes for either proline or arginine at codon 259. This polymorphism may affect the affinity of TC for B12 and subsequent delivery of B12 to tissues.Subjects/methodsTC genotype and its associations with indicators of B12 status, including total B12, holotranscobalamin (holoTC), methylmalonic acid and homocysteine, were evaluated in a cohort of elderly Latinos (N=554, age 60-93 years) from the Sacramento Area Latino Study on Aging (SALSA).ResultsThe distribution of TC genotypes was 41.3% homozygous reference (776CC) and 11.6% homozygous variant (776GG). No differences between the homozygous genotypes were observed in total B12, holoTC, methylmalonic acid or homocysteine. The holoTC/total B12 ratio was lower in the 776GG group compared with the 776CC group (P=0.04). Significant interactions of TC genotype with total B12 (P=0.04) and with holoTC (P< or =0.03) were observed such that mean homocysteine concentrations and the odds ratios for hyperhomocysteinemia (>13 micromol/l) were higher in the 776CC subjects compared with all carriers of the G allele (776CG and 776GG combined) when total B12 (<156 pmol/l) or holoTC (<35 pmol/l) were low.ConclusionsThis population of older Latinos has a lower prevalence of the TC 776GG variant than reported for Caucasian populations. The association between vitamin B12 and homocysteine concentrations is modified by TC 776 genotype. It remains to be determined whether the TC C776G polymorphism has a significant effect on the hematological and neurological manifestations of B12 deficiency or on vascular and other morbidities associated with hyperhomocysteinemia

    A Comprehensive Survey of Brane Tilings

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    An infinite class of 4d4d N=1\mathcal{N}=1 gauge theories can be engineered on the worldvolume of D3-branes probing toric Calabi-Yau 3-folds. This kind of setup has multiple applications, ranging from the gauge/gravity correspondence to local model building in string phenomenology. Brane tilings fully encode the gauge theories on the D3-branes and have substantially simplified their connection to the probed geometries. The purpose of this paper is to push the boundaries of computation and to produce as comprehensive a database of brane tilings as possible. We develop efficient implementations of brane tiling tools particularly suited for this search. We present the first complete classification of toric Calabi-Yau 3-folds with toric diagrams up to area 8 and the corresponding brane tilings. This classification is of interest to both physicists and mathematicians alike.Comment: 39 pages. Link to Mathematica modules provide

    The visual standards for the selection and retention of astronauts

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    Literature search with abstracts on visual performance standards for selection and retention of astronaut

    Seismic imaging of the Alaska Subduction Zone: implications for slab geometry and volcanism

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    Alaska has been a site of subduction and terrane accretion since the mid‐Jurassic. The area features abundant seismicity, active volcanism, rapid uplift, and broad intraplate deformation, all associated with subduction of the Pacific plate beneath North America. The juxtaposition of a slab edge with subducted, overthickened crust of the Yakutat terrane beneath central Alaska is associated with many enigmatic volcanic features. The causes of the Denali Volcanic Gap, a 400‐km‐long zone of volcanic quiescence west of the slab edge, are debated. Furthermore, the Wrangell Volcanic Field, southeast of the volcanic gap, also has an unexplained relationship with subduction. To address these issues, we present a joint ambient noise, earthquake‐based surface wave, and P‐S receiver function tomography model of Alaska, along with a teleseismic S wave velocity model. We compare the crust and mantle structure between the volcanic and nonvolcanic regions, across the eastern edge of the slab and between models. Low crustal velocities correspond to sedimentary basins, and several terrane boundaries are marked by changes in Moho depth. The continental lithosphere directly beneath the Denali Volcanic Gap is thicker than in the adjacent volcanic region. We suggest that shallow subduction here has cooled the mantle wedge, allowing the formation of thick lithosphere by the prevention of hot asthenosphere from reaching depths where it can interact with fluids released from the slab and promote volcanism. There is no evidence for subducted material east of the edge of the Yakutat terrane, implying the Wrangell Volcanic Field formed directly above a slab edge

    Non-Darcy flow characteristics of water as influenced by clay concentration

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    The flow of water through saturated samples of montmorillonite and kaolinite was studied to help clarify the existence and nature of non-Darcian flow. No threshold gradients were found in any of the samples studied. Non-Darcy flow was found in 9, 30 and 40 weight percent montmorillonite samples but not in a 50 weight percent montmorillonite or in kaolinite samples. The possible causes of the non-Darcian flow are discussed. A refined technique using a pressure transducer was developed to measure hydraulic conductivities. The hydraulic conductivities of several types of samples under varying conditions were measured. Transport equations for convective diffusion in porous media were derived and tested for capillaries, porous diaphragms, sand columns and clay plugs.U.S. Department of the InteriorU.S. Geological SurveyOpe

    Planet Four: Terrains - Discovery of Araneiforms Outside of the South Polar Layered Deposits

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    We present the results of a systematic mapping of seasonally sculpted terrains on the South Polar region of Mars with the Planet Four: Terrains (P4T) online citizen science project. P4T enlists members of the general public to visually identify features in the publicly released Mars Reconnaissance Orbiter CTX images. In particular, P4T volunteers are asked to identify: 1) araneiforms (including features with a central pit and radiating channels known as 'spiders'); 2) erosional depressions, troughs, mesas, ridges, and quasi-circular pits characteristic of the South Polar Residual Cap (SPRC) which we collectively refer to as 'Swiss cheese terrain', and 3) craters. In this work we present the distributions of our high confidence classic spider araneiforms and Swiss cheese terrain identifications. We find no locations within our high confidence spider sample that also have confident Swiss cheese terrain identifications. Previously spiders were reported as being confined to the South Polar Layered Deposits (SPLD). Our work has provided the first identification of spiders at locations outside of the SPLD, confirmed with high resolution HiRISE imaging. We find araneiforms on the Amazonian and Hesperian polar units and the Early Noachian highland units, with 75% of the identified araneiform locations in our high confidence sample residing on the SPLD. With our current coverage, we cannot confirm whether these are the only geologic units conducive to araneiform formation on the Martian South Polar region. Our results are consistent with the current CO2 jet formation scenario with the process exploiting weaknesses in the surface below the seasonal CO2 ice sheet to carve araneiform channels into the regolith over many seasons. These new regions serve as additional probes of the conditions required for channel creation in the CO2 jet process. (Abridged)Comment: accepted to Icarus - Supplemental data files are available at https://www.zooniverse.org/projects/mschwamb/planet-four-terrains/about/results - Icarus print version available at http://www.sciencedirect.com/science/article/pii/S001910351730055
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