211 research outputs found

    Probabilistic Bias Mitigation in Word Embeddings

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    It has been shown that word embeddings derived from large corpora tend to incorporate biases present in their training data. Various methods for mitigating these biases have been proposed, but recent work has demonstrated that these methods hide but fail to truly remove the biases, which can still be observed in word nearest-neighbor statistics. In this work we propose a probabilistic view of word embedding bias. We leverage this framework to present a novel method for mitigating bias which relies on probabilistic observations to yield a more robust bias mitigation algorithm. We demonstrate that this method effectively reduces bias according to three separate measures of bias while maintaining embedding quality across various popular benchmark semantic tasksComment: 4 pages, 4 figures, Workshop on Human-Centric Machine Learning at NeurIPS 201

    OCR Graph Features for Manipulation Detection in Documents

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    Detecting manipulations in digital documents is becoming increasingly important for information verification purposes. Due to the proliferation of image editing software, altering key information in documents has become widely accessible. Nearly all approaches in this domain rely on a procedural approach, using carefully generated features and a hand-tuned scoring system, rather than a data-driven and generalizable approach. We frame this issue as a graph comparison problem using the character bounding boxes, and propose a model that leverages graph features using OCR (Optical Character Recognition). Our model relies on a data-driven approach to detect alterations by training a random forest classifier on the graph-based OCR features. We evaluate our algorithm's forgery detection performance on dataset constructed from real business documents with slight forgery imperfections. Our proposed model dramatically outperforms the most closely-related document manipulation detection model on this task

    WHAT HAPPENS WHEN HOSPITALS NO LONGER HAVE A VOLUME INCENTIVE? EXAMINING THE MARYLAND GLOBAL BUDGET REVENUE PROGRAM.

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    ABSTRACT Hailey J. James: What Happens When Hospitals No Longer Have a Volume Incentive? Examining the Maryland Global Budget Revenue Program(Under the direction of Alyssa Mansfield Damon & George H. Pink) Background: A concern of the Maryland Global Budget Revenue (GBR) program is that its cost-containment financial incentive introduces a risk of hospitals seeking to avoid costly patient encounters. Objective: The goal of this research was to assess the impact of the Maryland GBR program for evidence of unintended consequences. Methods: This work includes three studies, two of which use econometric models to estimate the association of the Maryland GBR program with two outcomes conceptualized as potential spillover effects: probability of elective admission and emergency medical services (EMS) transport times. Difference-in-differences analyses were used to compare Maryland hospitals (Aim 1) and Maryland hospital service areas (Aim 3) to inverse probability of treatment weighted out-of-state comparators before and after policy implementation. Maryland simultaneously implemented its GBR program and expanded Medicaid, so comparator states were selected that expanded Medicaid the same day as Maryland. The third study (Aim 2) is a descriptive analysis of annual changes in interhospital transfers comparing rural to urban hospitals before and after policy implementation. Results: I found that the Maryland GBR program was associated a 5.2% (P =.004) increase in elective admissions among Medicaid and a 7.9% (P =.032) decrease among self-pay groups. Analysis of EMS transport times found an association between the Maryland GBR program and an increase in EMS transport times for cardiac arrest patients, but sensitivity analysis results suggest these effects could be confounded by changes in EMS agency reporting patterns. Finally, descriptive analyses of interhospital transfers showed that rural and urban hospitals experienced opposite trends in transfers in from other hospitals with the state’s two AMCs experiencing substantial decreases in transfers in following policy implementation. Conclusions: These three studies provide some evidence that there are unintended effects of the Maryland GBR program not previously considered. This work demonstrates a potential dual Medicaid-expansion/GBR program effect with changes in probability of elective admission limited to the two payer groups most affected by Medicaid expansion. Regarding transfers in, rural hospitals were differentially affected compared to urban hospitals, and the two AMCs experienced an unintended reduction despite the state intervening to incentivize the opposite result.Doctor of Philosoph

    DYffusion: A Dynamics-informed Diffusion Model for Spatiotemporal Forecasting

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    While diffusion models can successfully generate data and make predictions, they are predominantly designed for static images. We propose an approach for training diffusion models for dynamics forecasting that leverages the temporal dynamics encoded in the data, directly coupling it with the diffusion steps in the network. We train a stochastic, time-conditioned interpolator and a backbone forecaster network that mimic the forward and reverse processes of conventional diffusion models, respectively. This design choice naturally encodes multi-step and long-range forecasting capabilities, allowing for highly flexible, continuous-time sampling trajectories and the ability to trade-off performance with accelerated sampling at inference time. In addition, the dynamics-informed diffusion process imposes a strong inductive bias, allowing for improved computational efficiency compared to traditional Gaussian noise-based diffusion models. Our approach performs competitively on probabilistic skill score metrics in complex dynamics forecasting of sea surface temperatures, Navier-Stokes flows, and spring mesh systems.Comment: Code will be released at: https://github.com/Rose-STL-Lab/dyffusio

    Constraining the ISM Properties of the Cloverleaf Quasar Host Galaxy with Herschel Spectroscopy

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    We present Herschel observations of the far-infrared (FIR) fine-structure (FS) lines [C II]158 μm, [O I]63 μm, [O III]52 μm, and [Si II]35 μm in the z = 2.56 Cloverleaf quasar, and combine them with published data in an analysis of the dense interstellar medium (ISM) in this system. Observed [C II]158 μm, [O I]63 μm, and FIR continuum flux ratios are reproduced with photodissociation region (PDR) models characterized by moderate far-ultraviolet (FUV) radiation fields with G_0 = 0.3–1 × 10^3 and atomic gas densities n_H = 3–5 × 10^3 cm^(−3), depending on contributions to [C II]158 μm from ionized gas. We assess the contribution to the [C II]158 μm flux from an active galactic nucleus (AGN) narrow line region (NLR) using ground-based measurements of the [N II]122 μm transition, finding that the NLR can contribute at most 20%–30% of the observed [C II]158 μm flux. The PDR density and far-UV radiation fields inferred from the atomic lines are not consistent with the CO emission, indicating that the molecular gas excitation is not solely provided via UV heating from local star formation (SF), but requires an additional heating source. X-ray heating from the AGN is explored, and we find that X-ray-dominated region (XDR) models, in combination with PDR models, can match the CO cooling without overproducing the observed FS line emission. While this XDR/PDR solution is favored given the evidence for both X-rays and SF in the Cloverleaf, we also investigate alternatives for the warm molecular gas, finding that either mechanical heating via low-velocity shocks or an enhanced cosmic-ray ionization rate may also contribute. Finally, we include upper limits on two other measurements attempted in the Herschel program: [C II]158 μm in FSC 10214 and [O I]63 μm in APM 08279+5255

    Repellent Surface Applications for Pest Birds

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    Common pest birds in the United States include the non-native European starling (Sturnus vulgaris), house sparrow (Passer domesticus), and the pigeon (Columba livia domestica), as well as native birds including Canada geese (Branta canadensis) and gull species (Laridae). Large concentrations of pest birds can create human health hazards and monetary losses due to consumption of crops, depredation, and fecal contamination and accumulation. Fecal contamination hazards include the potential spread of zoonotic diseases including antimicrobial-resistant zoonoses and human injury due to the accumulation of fecal material on walking surfaces. Additionally, fecal accumulation causes structural and aesthetic damage due to the accelerated deterioration of building materials and increased maintenance costs. Methods to alleviate hazards and damages from aggregations of pest birds are needed. In a series of 3 experiments conducted in Fort Collins, Colorado, USA, between 2016 and 2018, we evaluated 3 surface-application repellent formulations for the reduction of fecal accumulations due to European starlings: Airepel® HC with castor oil, an anthraquinone-based repellent; Airepel HC with castor oil without anthraquinone; and MS2, a novel inert formulation with a tacky, oily texture. We compared each formulation directly to an untreated control. All 3 formulations reduced fecal accumulations beneath treated aluminum perches as compared to fecal accumulations beneath untreated aluminum perches. Interestingly, both formulations that contained no anthraquinone worked equally well or better than Airepel HC with castor oil, the anthraquinone-based formulation. The benefits of an exclusively inert formulation include less risk to applicators and non-target species. Comprehensive experimental field testing of these surface-application repellent formulations is warranted

    The Beta Problem: A Study of Abell 262

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    We present an investigation of the dynamical state of the cluster A262. Existing optical line of sight velocities for select cluster galaxies have been augmented by new data obtained with the Automated Multi-Object Spectrograph at Lick Observatory. We find evidence for a virialized early-type population distinct from a late-type population infalling from the Pisces-Perseus supercluster ridge. We also report on a tertiary population of low luminosity galaxies whose velocity dispersion distinguishes them from both the early and late-type galaxies. We supplement our investigation with an analysis of archival X-ray data. A temperature is determined using ASCA GIS data and a gas profile is derived from ROSAT HRI data. The increased statistics of our sample results in a picture of A262 with significant differences from earlier work. A previously proposed solution to the "beta-problem" in A262 in which the gas temperature is significantly higher than the galaxy temperature is shown to result from using too low a velocity dispersion for the early-type galaxies. Our data present a consistent picture of A262 in which there is no "beta-problem", and the gas and galaxy temperature are roughly comparable. There is no longer any requirement for extensive galaxy-gas feedback to drastically overheat the gas with respect to the galaxies. We also demonstrate that entropy-floor models can explain the recent discovery that the beta values determined by cluster gas and the cluster core radii are correlated.Comment: 31 pages, 14 figures, AAS LaTeX v5.0, Encapsulated Postscript figures, to be published in The Astrophysical Journa

    Evaluating the Medical Kit System for the International Space Station(ISS) - A Paradigm Revisited

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    Medical capabilities aboard the International Space Station (ISS) have been packaged to help astronaut crew medical officers (CMO) mitigate both urgent and non-urgent medical issues during their 6-month expeditions. Two ISS crewmembers are designated as CMOs for each 3-crewmember mission and are typically not physicians. In addition, the ISS may have communication gaps of up to 45 minutes during each orbit, necessitating medical equipment that can be reliably operated autonomously during flight. The retirement of the space shuttle combined with ten years of manned ISS expeditions led the Space Medicine Division at the NASA Johnson Space Center to reassess the current ISS Medical Kit System. This reassessment led to the system being streamlined to meet future logistical considerations with current Russian space vehicles and future NASA/commercial space vehicle systems. Methods The JSC Space Medicine Division coordinated the development of requirements, fabrication of prototypes, and conducted usability testing for the new ISS Medical Kit System in concert with implementing updated versions of the ISS Medical Check List and associated in-flight software applications. The teams constructed a medical kit system with the flexibility for use on the ISS, and resupply on the Russian Progress space vehicle and future NASA/commercial space vehicles. Results Prototype systems were developed, reviewed, and tested for implementation. Completion of Preliminary and Critical Design Reviews resulted in a streamlined ISS Medical Kit System that is being used for training by ISS crews starting with Expedition 27 (June 2011). Conclusions The team will present the process for designing, developing, , implementing, and training with this new ISS Medical Kit System
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