6,348 research outputs found

    DataWarp: Building Applications which Make Progress in an Inconsistent World

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    The usual approach to dealing with imperfections in data is to attempt to eliminate them. However, the nature of modern systems means this is often futile. This paper describes an approach which permits applications to operate notwithstanding inconsistent data. Instead of attempting to extract a single, correct view of the world from its data, a DataWarp application constructs a collection of interpretations. It adopts one of these and continues work. Since it acts on assumptions, the DataWarp application considers its recent work to be provisional, expecting eventually most of these actions will become definitive. Should the application decide to adopt an alternative data view, it may then need to void provisional actions before resuming work. We describe the DataWarp architecture, discuss its implementation and describe an experiment in which a DataWarp application in an environment containing inconsistent data achieves better results than its conventional counterpart

    Heartbeat Anomaly Detection using Adversarial Oversampling

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    Cardiovascular diseases are one of the most common causes of death in the world. Prevention, knowledge of previous cases in the family, and early detection is the best strategy to reduce this fact. Different machine learning approaches to automatic diagnostic are being proposed to this task. As in most health problems, the imbalance between examples and classes is predominant in this problem and affects the performance of the automated solution. In this paper, we address the classification of heartbeats images in different cardiovascular diseases. We propose a two-dimensional Convolutional Neural Network for classification after using a InfoGAN architecture for generating synthetic images to unbalanced classes. We call this proposal Adversarial Oversampling and compare it with the classical oversampling methods as SMOTE, ADASYN, and RandomOversampling. The results show that the proposed approach improves the classifier performance for the minority classes without harming the performance in the balanced classes

    Properties of real metallic surfaces: Effects of density functional semilocality and van der Waals nonlocality

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    We have computed the surface energies, work functions, and interlayer surface relaxations of clean (111), (110), and (100) surfaces of Al, Cu, Ru, Rh, Pd, Ag, Pt, and Au. Many of these metallic surfaces have technological or catalytic applications. We compare experimental reference values to those of the local density approximation (LDA), the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA), the PBEsol (PBE for solids) GGA, the SCAN meta-GGA, and SCAN+rVV10 (SCAN with a long-range van der Waals or vdW correction). The closest agreement with uncertain experimental values is achieved by the simplest density functional (LDA) and by the most sophisticated general-purpose one (SCAN+rVV10). The long-range vdW interaction increases the surface energies by about 10%, and the work functions by about 1%. LDA works for metal surfaces through a stronger-than-usual error cancellation. PBE yields the most-underestimated and presumably least accurate surface energies and work functions. Surface energies within the random phase approximation (RPA) are also reported. Interlayer relaxations from different functionals are in reasonable agreement with one another, and usually with experiment

    Historical Motivations for the Siege of Minas Tirith

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    Traces possible historical models for the Siege of Minas Tirith, particularly the fall of Constantinople in 1453

    A Forensic Investigation into the Possible Origins of Three Human Skeletons

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    The Anthropology Department at Buffalo State has three human skeletons that have been part of the department’s collection for several years. The origin of the skeletons is currently unknown. Modern DNA techniques coupled with forensic anthropological techniques may now allow us to determine with some certainty the geographic origin of the skeletons. Ancestry, sex, age, and stature were assessed using current anthropological techniques. Afterwards, one tooth from each of the three skeletons was extracted, pulverized and DNA was isolated. Y-STR fragment size analysis of the DNA samples can provide information about the patrilineage of male individuals. Mitochondrial DNA sequencing analysis can provide information about the matrilineage of the individuals. All of the individuals appear to be two males and one probable female of Eurasian ancestry, ranging in stature from 5’3” to 5’8”, and all estimated to be over 30 years old at time of death
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