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  1. Hardt, M. (Ed.)
  2. There is a rapidly growing demand for individuals in cybersecurity and a deficit of persons able to fill those roles. To help meet this need, students not majoring in computing can be utilized to fulfill this demand by exposing them to date mining, cybersecurity practices, and applications of these concepts in the field. This paper presents findings from a twenty-one-week program in which minority undergraduate college students all members of the Reserve Officer Training Coprs (ROTC), were taught computer programming, natural language processing, data visualization, and computer vision fundamentals. Midshipmen and cadets used their newly gained knowledge, teamwork, planning, and communication skills to develop a threat dectection prototype using publicly available social media data. Resuls from pre and post python assessments and post-program interviews that recorded participant attitudes and sefl-efficacy are reported to highlight the programs' effectiveness. 
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  3. This Research Full Paper presents a qualitative interview study on the effectiveness of a computing identity development listserv. The demand for diverse computing careers increases, yet African Americans continue to participate and succeed in computing fields proportionately less than their White and Asian counterparts. An individual’s computing identity can influence their performance and willingness to participate. The African American PhDs in Computer Science Listserv is an email listserv created to increase and maintain members’ sense of belonging, self-efficacy, and resilience in computing. Semistructured interviews of graduate student, faculty, and industry professional members were conducted to investigate how effective the listserv was at increasing and maintaining computing identity. Findings include decision making processes for joining, duration and dosage of interaction members partake, maintenance of computing resilience, members’ self-reflection, willingness to seek help, and attitudes towards computing. Recommendations were made about the listserv and if other African Americans in computing should join. Findings can be used to develop new approaches to supporting the computing identities of underrepresented groups. This paper is in conjunction with other papers in an extended case study on resilient identity development in African American computer scientists. 
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  4. To improve the academic and professional achievement of underrepresented minorities in computing, a newfound interest in innovative mentoring practices has captivated STEM education researchers. Studies suggest that virtual mentoring conversational agents can be leveraged across multiple platforms to provide supplemental mentorship, offsetting the lack of access to in-person mentorship in disadvantaged communities. A within-subjects mixed-method experiment was carried out to assess the usability of a mentoring conversational agent. Mobile interfaces (Twitter and SMS) were compared to each other and against a web-based embodied conversational agent (ECA). Results suggest that mobile interfaces are more usable than the web-based ECA. The findings from this study help to identify areas for improvement in virtual learning alternatives and other potential applications for pervasive conversational interfaces. 
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  5. Free, publicly-accessible full text available December 1, 2024
  6. Abstract

    We search for gravitational-wave (GW) transients associated with fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project, during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC–2019 October 1 15:00 UTC). Triggers from 22 FRBs were analyzed with a search that targets both binary neutron star (BNS) and neutron star–black hole (NSBH) mergers. A targeted search for generic GW transients was conducted on 40 FRBs. We find no significant evidence for a GW association in either search. Given the large uncertainties in the distances of our FRB sample, we are unable to exclude the possibility of a GW association. Assessing the volumetric event rates of both FRB and binary mergers, an association is limited to 15% of the FRB population for BNS mergers or 1% for NSBH mergers. We report 90% confidence lower bounds on the distance to each FRB for a range of GW progenitor models and set upper limits on the energy emitted through GWs for a range of emission scenarios. We find values of order 1051–1057erg for models with central GW frequencies in the range 70–3560 Hz. At the sensitivity of this search, we find these limits to be above the predicted GW emissions for the models considered. We also find no significant coincident detection of GWs with the repeater, FRB 20200120E, which is the closest known extragalactic FRB.

     
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    Free, publicly-accessible full text available September 28, 2024
  7. Abstract The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org . The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages. 
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    Free, publicly-accessible full text available July 28, 2024
  8. Abstract We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H ( z ), including its current value, the Hubble constant H 0 . Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H ( z ). The source mass distribution displays a peak around 34 M ⊙ , followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H ( z ) measurement, yielding H 0 = 68 − 8 + 12 km s − 1 Mpc − 1 (68% credible interval) when combined with the H 0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H 0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+ , statistically marginalizing over the redshifts of each event’s potential hosts. Assuming a fixed BBH population, we estimate a value of H 0 = 68 − 6 + 8 km s − 1 Mpc − 1 with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H 0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H 0 ) is the well-localized event GW190814. 
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    Free, publicly-accessible full text available June 1, 2024
  9. Free, publicly-accessible full text available March 1, 2024
  10. Abstract We present the results of a model-based search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1 using LIGO detector data from the third observing run of Advanced LIGO and Advanced Virgo. This is a semicoherent search that uses details of the signal model to coherently combine data separated by less than a specified coherence time, which can be adjusted to balance sensitivity with computing cost. The search covered a range of gravitational-wave frequencies from 25 to 1600 Hz, as well as ranges in orbital speed, frequency, and phase determined from observational constraints. No significant detection candidates were found, and upper limits were set as a function of frequency. The most stringent limits, between 100 and 200 Hz, correspond to an amplitude h 0 of about 10 −25 when marginalized isotropically over the unknown inclination angle of the neutron star’s rotation axis, or less than 4 × 10 −26 assuming the optimal orientation. The sensitivity of this search is now probing amplitudes predicted by models of torque balance equilibrium. For the usual conservative model assuming accretion at the surface of the neutron star, our isotropically marginalized upper limits are close to the predicted amplitude from about 70 to 100 Hz; the limits assuming that the neutron star spin is aligned with the most likely orbital angular momentum are below the conservative torque balance predictions from 40 to 200 Hz. Assuming a broader range of accretion models, our direct limits on gravitational-wave amplitude delve into the relevant parameter space over a wide range of frequencies, to 500 Hz or more. 
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