Catholic University of America
UniversityWashington, District of Columbia, United States
Research output, citation impact, and the most-cited recent papers from Catholic University of America (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from Catholic University of America
This paper addresses theoretical, empirical, and analytical studies pertaining to human use, misuse, disuse, and abuse of automation technology. Use refers to the voluntary activation or disengagement of automation by human operators. Trust, mental workload, and risk can influence automation use, but interactions between factors and large individual differences make prediction of automation use difficult. Misuse refers to over reliance on automation, which can result in failures of monitoring or decision biases. Factors affecting the monitoring of automation include workload, automation reliability and consistency, and the saliency of automation state indicators. Disuse, or the neglect or underutilization of automation, is commonly caused by alarms that activate falsely. This often occurs because the base rate of the condition to be detected is not considered in setting the trade-off between false alarms and omissions. Automation abuse, or the automation of functions by designers and implementation by managers without due regard for the consequences for human performance, tends to define the operator's roles as by-products of the automation. Automation abuse can also promote misuse and disuse of automation by human operators. Understanding the factors associated with each of these aspects of human use of automation can lead to improved system design, effective training methods, and judicious policies and procedures involving automation use.
The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are suitable for water to exist on a planet's surface. During the first 6 weeks of observations, Kepler monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 days were discovered. The density of the Neptune-sized Kepler-4b is similar to that of Neptune and GJ 436b, even though the irradiation level is 800,000 times higher. Kepler-7b is one of the lowest-density planets (approximately 0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets.
Technical developments in computer hardware and software now make it possible to introduce automation into virtually all aspects of human-machine systems. Given these technical capabilities, which system functions should be automated and to what extent? We outline a model for types and levels of automation that provides a framework and an objective basis for making such choices. Appropriate selection is important because automation does not merely supplant but changes human activity and can impose new coordination demands on the human operator. We propose that automation can be applied to four broad classes of functions: 1) information acquisition; 2) information analysis; 3) decision and action selection; and 4) action implementation. Within each of these types, automation can be applied across a continuum of levels from low to high, i.e., from fully manual to fully automatic. A particular system can involve automation of all four types at different levels. The human performance consequences of particular types and levels of automation constitute primary evaluative criteria for automation design using our model. Secondary evaluative criteria include automation reliability and the costs of decision/action consequences, among others. Examples of recommended types and levels of automation are provided to illustrate the application of the model to automation design.
The Sloan Digital Sky Survey (SDSS) is an imaging and spectroscopic survey that will eventually cover approximately one-quarter of the celestial sphere and collect spectra of ≈10 6 galaxies, 100,000 quasars, 30,000 stars, and 30,000 serendipity targets. In 2001 June, the SDSS released to the general astronomical community its early data release, roughly 462 deg 2 of imaging data including almost 14 million detected objects and 54,008 follow-up spectra. The imaging data were collected in drift-scan mode in five bandpasses ( u , g , r , i , and z ); our 95% completeness limits for stars are 22.0, 22.2, 22.2, 21.3, and 20.5, respectively. The photometric calibration is reproducible to 5%, 3%, 3%, 3%, and 5%, respectively. The spectra are flux- and wavelength-calibrated, with 4096 pixels from 3800 to 9200 Å at R ≈ 1800. We present the means by which these data are distributed to the astronomical community, descriptions of the hardware used to obtain the data, the software used for processing the data, the measured quantities for each observed object, and an overview of the properties of this data set.
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift ( z ) range 8–1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope , from the mid-ultraviolet to the near-infrared, and will find and measure Type Ia supernovae at z > 1.5 to test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 10 9 M ☉ to z ≈ 2, reaching the knee of the ultraviolet luminosity function of galaxies to z ≈ 8. The survey covers approximately 800 arcmin 2 and is divided into two parts. The CANDELS/Deep survey (5σ point-source limit H = 27.7 mag) covers ∼125 arcmin 2 within Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (Extended Groth Strip, COSMOS, and Ultra-deep Survey) and covers the full area to a 5σ point-source limit of H ≳ 27.0 mag. Together with the Hubble Ultra Deep Fields, the strategy creates a three-tiered "wedding-cake" approach that has proven efficient for extragalactic surveys. Data from the survey are nonproprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design. The Hubble data processing and products are described in a companion paper.
Some Elements of Mechanics. Effective Moduli: Spherical Inclusions. Effective Moduli: Cylindrical and Lamellar Systems. Bounds of Effective Moduli and Further Results. Laminates. Analysis, Strength, and Design. Wave Propagation. Inelastic and Non-linear Effects. Effective Thermal Properties. Index.
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decades and, in particular, the focused ten-week program on “Gluons and quark sea at high energies” at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them. It has been benefited profoundly from inputs by the users’ communities of BNL and JLab. This White Paper offers the promise to propel the QCD science program in the US, established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.
This paper describes the Sixth Data Release of the Sloan Digital Sky Survey. With this data release, the imaging of the northern Galactic cap is now complete. The survey contains images and parameters of roughly 287 million objects over 9583 deg 2 , including scans over a large range of Galactic latitudes and longitudes. The survey also includes 1.27 million spectra of stars, galaxies, quasars, and blank sky (for sky subtraction) selected over 7425 deg 2 . This release includes much more stellar spectroscopy than was available in previous data releases and also includes detailed estimates of stellar temperatures, gravities, and metallicities. The results of improved photometric calibration are now available, with uncertainties of roughly 1% in g , r , i , and z , and 2% in u , substantially better than the uncertainties in previous data releases. The spectra in this data release have improved wavelength and flux calibration, especially in the extreme blue and extreme red, leading to the qualitatively better determination of stellar types and radial velocities. The spectrophotometric fluxes are now tied to point-spread function magnitudes of stars rather than fiber magnitudes. This gives more robust results in the presence of seeing variations, but also implies a change in the spectrophotometric scale, which is now brighter by roughly 0.35 mag. Systematic errors in the velocity dispersions of galaxies have been fixed, and the results of two independent codes for determining spectral classifications and redshifts are made available. Additional spectral outputs are made available, including calibrated spectra from individual 15 minute exposures and the sky spectrum subtracted from each exposure. We also quantify a recently recognized underestimation of the brightnesses of galaxies of large angular extent due to poor sky subtraction; the bias can exceed 0.2 mag for galaxies brighter than r = 14 mag.
The Fast Plasma Investigation (FPI) was developed for flight on the Magnetospheric Multiscale (MMS) mission to measure the differential directional flux of magnetospheric electrons and ions with unprecedented time resolution to resolve kinetic-scale plasma dynamics. This increased resolution has been accomplished by placing four dual 180-degree top hat spectrometers for electrons and four dual 180-degree top hat spectrometers for ions around the periphery of each of four MMS spacecraft. Using electrostatic field-of-view deflection, the eight spectrometers for each species together provide 4pi-sr field-of-view with, at worst, 11.25-degree sample spacing. Energy/charge sampling is provided by swept electrostatic energy/charge selection over the range from 10 eV/q to 30000 eV/q. The eight dual spectrometers on each spacecraft are controlled and interrogated by a single block redundant Instrument Data Processing Unit, which in turn interfaces to the observatory’s Instrument Suite Central Instrument Data Processor. This paper describes the design of FPI, its ground and in-flight calibration, its operational concept, and its data products.
Here we report the identification of a novel human opsin, melanopsin, that is expressed in cells of the mammalian inner retina. The human melanopsin gene consists of 10 exons and is mapped to chromosome 10q22. This chromosomal localization and gene structure differs significantly from that of other human opsins that typically have four to seven exons. A survey of 26 anatomical sites indicates that, in humans, melanopsin is expressed only in the eye. In situ hybridization histochemistry shows that melanopsin expression is restricted to cells within the ganglion and amacrine cell layers of the primate and murine retinas. Notably, expression is not observed in retinal photoreceptor cells, the opsin-containing cells of the outer retina that initiate vision. The unique inner retinal localization of melanopsin suggests that it is not involved in image formation but rather may mediate nonvisual photoreceptive tasks, such as the regulation of circadian rhythms and the acute suppression of pineal melatonin. The anatomical distribution of melanopsin-positive retinal cells is similar to the pattern of cells known to project from the retina to the suprachiasmatic nuclei of the hypothalamus, a primary circadian pacemaker.
We report on the results from the first six months of the Catalina Real-Time Transient Survey (CRTS). In order to search for optical transients (OTs) with timescales of minutes to years, the CRTS analyses data from the Catalina Sky Survey which repeatedly covers 26,000 of square degrees on the sky. The CRTS provides a public stream of transients that are bright enough to be followed up using small telescopes. Since the beginning of the survey, all CRTS transients have been made available to astronomers around the world in real time using HTML tables,RSS feeds, and VOEvents. As part of our public outreach program, the detections are now also available in Keyhole Markup Language through Google Sky. The initial discoveries include over 350 unique OTs rising more than 2 mag from past measurements. Sixty two of these are classified as supernovae (SNe), based on light curves, prior deep imaging and spectroscopic data. Seventy seven are due to cataclysmic variables (CVs; only 13 previously known), while an additional 100 transients were too infrequently sampled to distinguish between faint CVs and SNe. The remaining OTs include active galactic nucleus, blazars, high-proper-motions stars, highly variable stars (such as UV Ceti stars), and transients of an unknown nature. Our results suggest that there is a large population of SNe missed by many current SN surveys because of selection biases. These objects appear to be associated with faint host galaxies. We also discuss the unexpected discovery of white dwarf binary systems through dramatic eclipses.
From the Publisher: This book describes the extremely powerful technique of molecular dynamics simulation, which involves solving the classical many-body problem in contexts relevant to the study of matter at the atomic level. The method allows the prediction of the static and dynamic properties of substances directly from the underlying interactions between the molecules. Because there is no alternative approach capable of handling such a broad range of problems at the required level of detail, molecular dynamics methods have proved themselves indispensable in both pure and applied research.
An equation derived by Ritland relating the cooling rate and fictive temperature for glasses without memory is extended to those with memory, i.e. those which exhibit a spectrum of relaxation times. Provided that the spectrum of relaxation times is temperature‐independent, the limiting fictive temperature, T′ f , obtained when a glass is cooled through the transition region, is shown to be related to the cooling rate, q , by d In | q |/ d (1/ T'f )=‐Δ h ★/ R where R is the ideal gas constant and Δ h ★ the activation enthalpy for the relaxation times controlling the structural relaxation. Values of T′ f vs q obtained from enthalpy measurements by differential scanning calorimetry are presented for B 2 O 3 , 0.4Ca(NO 3 ) 2 —0.6KNO 3 , and borosilicate crown glasses; Δ h ★ is equal, within experimental error, to the activation enthalpy for shear viscosity. Values of T′ f from volume and enthalpy measurements obtained at the same cooling rate for the borosilicate crown glass are equal.
We present a calculation of the dielectric correlation function in glasses showing how the assumption of short correlation length for normal modes breaks the momentum selection rules and leads to expressions for the first-order Raman-scattering intensity in terms of the density-of-states functions and known frequency-dependent amplitudes.
After interviews with teenagers, Youniss and Smollar find that, though adolescents seek independence from the parent-child bond, they do not abandon the relationship. A must for anyone interested in adolescent behavior.--Edward Z. Dager, Contemporary Sociology
This paper describes the Fourth Data Release of the Sloan Digital Sky Survey (SDSS), including all survey-quality data taken through 2004 June. The data release includes five-band photometric data for 180 million objects selected over 6670 deg 2 and 673,280 spectra of galaxies, quasars, and stars selected from 4783 deg 2 of those imaging data using the standard SDSS target selection algorithms. These numbers represent a roughly 27% increment over those of the Third Data Release; all the data from previous data releases are included in the present release. The Fourth Data Release also includes an additional 131,840 spectra of objects selected using a variety of alternative algorithms, to address scientific issues ranging from the kinematics of stars in the Milky Way thick disk to populations of faint galaxies and quasars.
Vibrational relaxation times in gases are calculated with the method of Zener using an exponential repulsion in a one-dimensional model. The constants of the interaction potential are determined by fitting it to the data of Hirschfelder, et al. The great effect which some impurities have is accounted for either by their low mass and resultant high velocity or by ``near resonance'' transfers in which the vibrational quantum of the substratum is used partly to excite the vibration of the impurity, only the difference being transferred to translation. However, there are other impurities, the action of which cannot be explained in this manner. The theoretical values for the relaxation times are 10 to 30 times shorter than the experimental ones, which difference may be accounted for by the use of the one-dimensional model. Macroscopic equations governing the more complex relaxation processes in polyatomic gases and gas mixtures are developed.
The Solar and Heliospheric Observatory (SOHO) mission's white light coronagraphs have observed nearly 7000 coronal mass ejections (CMEs) between 1996 and 2002. We have documented the measured properties of all these CMEs in an online catalog. We describe this catalog and present a summary of the statistical properties of the CMEs. The primary measurements made on each CME are the apparent central position angle, the angular width in the sky plane, and the height (heliocentric distance) as a function of time. The height‐time measurements are then fitted to first‐ and second‐order polynomials to derive the average apparent speed and acceleration of the CMEs. The statistical properties of CMEs are (1) the average width of normal CMEs (20° < width ≤ 120°) increased from 47° (1996; solar minimum) to 61° (1999; early phase of solar maximum) and then decreased to 53° (2002; late phase of solar maximum), (2) CMEs were detected around the equatorial region during solar minimum, while during solar maximum CMEs appear at all latitudes, (3) the average apparent speed of CMEs increases from 300 km s −1 (solar minimum) to 500 km s −1 (solar maximum), (4) the average apparent speed of halo CMEs (957 km s −1 ) is twice of that of normal CMEs (428 km s −1 ), and (5) most of the slow CMEs ( V ≤ 250 km s −1 ) show acceleration while most of the fast CMEs ( V > 900 km s −1 ) show deceleration. Solar cycle variation and statistical properties of CMEs are revealed with greater clarity in this study as compared with previous studies. Implications of our findings for CME models are discussed.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThree methods to measure RH bond energiesJoseph Berkowitz, G. Barney Ellison, and David GutmanCite this: J. Phys. Chem. 1994, 98, 11, 2744–2765Publication Date (Print):March 1, 1994Publication History Published online1 May 2002Published inissue 1 March 1994https://pubs.acs.org/doi/10.1021/j100062a009https://doi.org/10.1021/j100062a009research-articleACS PublicationsRequest reuse permissionsArticle Views3187Altmetric-Citations992LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
The CMS apparatus was identified, a few years before the start of the LHC operation at CERN, to feature properties well suited to particle-flow (PF) reconstruction: a highly-segmented tracker, a fine-grained electromagnetic calorimeter, a hermetic hadron calorimeter, a strong magnetic field, and an excellent muon spectrometer.A fully-fledged PF reconstruction algorithm tuned to the CMS detector was therefore developed and has been consistently used in physics analyses for the first time at a hadron collider.For each collision, the comprehensive list of final-state particles identified and reconstructed by the algorithm provides a global event description that leads to unprecedented CMS performance for jet and hadronic τ decay reconstruction, missing transverse momentum determination, and electron and muon identification.This approach also allows particles from pileup interactions to be identified and enables efficient pileup mitigation methods.The data collected by CMS at a centre-of-mass energy of 8 TeV show excellent agreement with the simulation and confirm the superior PF performance at least up to an average of 20 pileup interactions.