5,972 research outputs found

    An Egocentric Spatial Data Model for Intelligent Mobile Geographic Information Systems

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    Individuals in unknown locations, such as utility workers in the field, soldiers on a mission, or sightseeing tourists, share the need for an answer to two basic questions: Where am I? and What is in front of me?Because such information is not readily available in foreign locations, aids in the form of paper maps or mobile GISs, which give individuals an all-inclusive view of the environment, are often used. This panoptic view may hinder the positioning and orienteering process, since people perceive their surroundings perspectively from their current position. In this thesis, I describe a novel framework that resolves this problem by applying sensors that gather the individual\u27s spatial frame of reference. This spatial frame of reference, in combination with an egocentric spatial data model enables an injective mapping between the real world and the data frame of reference, hence, alleviating the individual\u27s cognitive workload. Furthermore, our egocentric spatial data model allows intelligent mobile Geographic Information Systems to capture the notions of here and there, and, consequently, provides insight into the individual\u27s surroundings. Finally, our framework, in conjunction with the context given by the task to be performed, enables intelligent mobile Geographic Information Systems to implicitly answer questions with respect to where, what, and how

    Emerging Field of Cardiomics: High-Throughput Investigations into Transcriptional Regulation of Cardiovascular Development and Disease

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    Congenital heart defects remain a leading cause of infant mortality in the western world, despite decades of research focusing on cardiovascular development and disease,. With the recent emergence of several high-throughput technologies including RNA sequencing, chromatin immunoprecipitation-coupled sequencing, mass spectrometry-based proteomics analyses, and the numerous variations of these strategies, investigations into cardiac development have been transformed from candidate-based studies into whole-genome, -transcriptome, and -proteome undertakings. In this review, we discuss several reports that have emerged from our lab and others over the last five years that emphasize the versatility of large dataset-based investigations of cardiogenic transcription factors, from phenotypic validations and new gene implications to the identification of novel roles of well-studied transcriptional regulators

    Characterization of Prepreg Tack for Composite Manufacturing by Automated Fiber Placement

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    Automated fiber placement (AFP) has become the industry standard for large-scale production of carbon fiber reinforced plastics (CFRP) to improve rate and reduce defects associated with manual layup. Still, defects generated during AFP processes require manual, painstaking inspection by technicians and rework of the part when substantial defects are found. Prepreg (carbon fiber infused with uncured epoxy resin) tack is one of the primary factors that influences the generation of defects that arise during auto-mated fiber placement (AFP). Tack, as it relates to AFP processes and defect formation, can be understood as a combination of two stages, cohesion and decohesion. During the cohesion phase, two pieces of prepreg are brought into contact under elevated temperature and pressure. Compaction of the resin within the contact area will result in a degree of intimate contact, I, between the mating prepreg surfaces. Defect formation, as a result of decohesion between prepreg surfaces, occurs after the cohesion phase and arises due to stress from events such as fiber placement over an existing defect, on a contoured path, etc. (Figure 1). Tack strength resists the displacement of prepreg on a surface due to stresses developed during deposition

    The role of dredge-up in double white dwarf mergers

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    We present the results of an investigation of the dredge-up and mixing during the merger of two white dwarfs with different chemical compositions by conducting hydrodynamic simulations of binary mergers for three representative mass ratios. In all the simulations, the total mass of the two white dwarfs is 1.0 M\lesssim1.0~{\rm M_\odot}. Mergers involving a CO and a He white dwarf have been suggested as a possible formation channel for R Coronae Borealis type stars, and we are interested in testing if such mergers lead to conditions and outcomes in agreement with observations. Even if the conditions during the merger and subsequent nucleosynthesis favor the production of 18O^{18}{\mathrm O}, the merger must avoid dredging up large amounts of 16O^{16}{\mathrm O}, or else it will be difficult to produce sufficient 18O^{18}{\mathrm O} to explain the oxygen ratio observed to be of order unity. We performed a total of 9 simulations using two different grid-based hydrodynamics codes using fixed and adaptive meshes, and one smooth particle hydrodynamics (SPH) code. We find that in most of the simulations, >102 M>10^{-2}~{\rm M_\odot} of 16O^{16}{\mathrm O} is indeed dredged up during the merger. However, in SPH simulations where the accretor is a hybrid He/CO white dwarf with a 0.1 M\sim 0.1~{\rm M_\odot} layer of helium on top, we find that no 16O^{16}{\mathrm O} is being dredged up, while in the q=0.8q=0.8 simulation <104 M<10^{-4}~{\rm M_\odot} of 16O^{16}{\mathrm O} has been brought up, making a WD binary consisting of a hybrid CO/He WD and a companion He WD an excellent candidate for the progenitor of RCB stars.Comment: Accepted for publication in Ap

    FIREBALL: Detector, data acquisition and reduction

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    The Faint Intergalactic Redshifted Emission Balloon (FIREBALL) had its first scientific flight in June 2009. The instrument combines microchannel plate detector technology with fiber-fed integral field spectroscopy on an unstable stratospheric balloon gondola platform. This unique combination poses a series of calibration and data reduction challenges that must be addressed and resolved to allow for accurate data analysis. We discuss our approach and some of the methods we are employing to accomplish this task

    Plans for a 10-m Submillimeter-wave Telescope at the South Pole

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    A 10 meter diameter submillimeter-wave telescope has been proposed for the NSF Amundsen-Scott South Pole Station. Current evidence indicates that the South Pole is the best submillimeter-wave telescope site among all existing or proposed ground-based observatories. Proposed scientific programs place stringent requirements on the optical quality of the telescope design. In particular, reduction of the thermal background and offsets requires an off-axis, unblocked aperture, and the large field of view needed for survey observations requires shaped optics. This mix of design elements is well-suited for large scale (square degree) mapping of line and continuum radiation from submillimeter-wave sources at moderate spatial resolutions (4 to 60 arcsecond beam size) and high sensitivity (milliJansky flux density levels). the telescope will make arcminute angular scale, high frequency Cosmic Microwave Background measurements from the best possible ground-based site, using an aperture which is larger than is currently possible on orbital or airborne platforms. Effective use of this telescope will require development of large (1000 element) arrays of submillimeter detectors which are background-limited when illuminated by antenna temperatures near 50 K.Comment: 12 pages, 3 figure

    Precise Measures of Orbital Period, Before and After Nova Eruption for QZ Aurigae

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    For the ordinary classical nova QZ Aurigae (which erupted in 1964), we report 1317 magnitudes from 1912--2016, including four eclipses detected on archival photographic plates from long before the eruption. We have accurate and robust measures of the orbital period both pre-eruption and post-eruption, and we find that the orbital period decreased, with a fractional change of -290.71+-0.28 parts-per-million across the eruption, with the orbit necessarily getting smaller. Further, we find that the light curve outside of eclipses and eruption is flat at near B=17.14 from 1912--1981, whereupon the average light curve starts fading down to B=17.49 with large variability. QZ Aur is a robust counter-example against the Hibernation model for the evolution of cataclysmic variables, where the model requires that all novae have their period increase across eruptions. Large period decreases across eruptions can easily arise from mass imbalances in the ejecta, as are commonly seen in asymmetric nova shells.Comment: MNRAS in press, 24 pages, 5 tables, 6 figure

    Asymmetrically Difunctionalized 1,1′-Ferrocenyl Metalloligands and Their Transition Metal Complexes

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    FcBipy: Novel redox-active bipyridine ligands based on 1,1′ difunctionalized ferrocenyl backbone, in conjunction with their metal complexes, are reported. The influence of the implemented functional groups on both the iron-centred redox potential and the N,N′-coordinated nickel complexes were confirmed for the reductive elimination reaction of an aryl ether induced by oxidation of the corresponding methoxides
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