Classification with Asymmetric Label Noise: Consistency and Maximal Denoising

In many real-world classification problems, the labels of training examples are randomly corrupted. Most previous theoretical work on classification with label noise assumes that the two classes are separable, that the label noise is independent of the true class label, or that the noise proportions for each class are known. In this work, we give conditions that are necessary and sufficient for the true class-conditional distributions to be identifiable. These conditions are weaker than those analyzed previously, and allow for the classes to be nonseparable and the noise levels to be asymmetric and unknown. The conditions essentially state that a majority of the observed labels are correct and that the true class-conditional distributions are "mutually irreducible," a concept we introduce that limits the similarity of the two distributions. For any label noise problem, there is a unique pair of true class-conditional distributions satisfying the proposed conditions, and we argue that this pair corresponds in a certain sense to maximal denoising of the observed distributions. Our results are facilitated by a connection to "mixture proportion estimation," which is the problem of estimating the maximal proportion of one distribution that is present in another. We establish a novel rate of convergence result for mixture proportion estimation, and apply this to obtain consistency of a discrimination rule based on surrogate loss minimization. Experimental results on benchmark data and a nuclear particle classification problem demonstrate the efficacy of our approach

Derivation and quantitative analysis of the differential self-interrogation Feynman-alpha method

A stochastic theory for a branching process in a neutron population with two energy levels is used to assess the applicability of the differential self-interrogation Feynman-alpha method by numerically estimated reaction intensities from Monte Carlo simulations. More specifically, the variance to mean or Feynman-alpha formula is applied to investigate the appearing exponentials using the numerically obtained reaction intensities.Comment: Proceedings 52nd INMM conference, Palm Desert, 17-21 July 201

Analysis of postures for handwriting on touch screens without using tools

The act of handwriting affected the evolutionary development of humans and still impacts the motor cognition of individuals. However, the ubiquitous use of digital technologies has drastically decreased the number of times we really need to pick a pen up and write on paper. Nonetheless, the positive cognitive impact of handwriting is widely recognized, and a possible way to merge the benefits of handwriting and digital writing is to use suitable tools to write over touchscreens or graphics tablets. In this manuscript, we focus on the possibility of using the hand itself as a writing tool. A novel hand posture named FingerPen is introduced, and can be seen as a grasp performed by the hand on the index finger. A comparison with the most common posture that people tend to assume (i.e. index finger-only exploitation) is carried out by means of a biomechanical model. A conducted user study shows that the FingerPen is appreciated by users and leads to accurate writing traits

Integrating home monitoring for transcranial direct current stimulation (tDCS) therapy to professional care environment

Daily management of neurodegenerative diseases is one of the most striking scenarios where an integrated health care system is essential for the continuous assistance to the patient and requires qualification of the caregivers and their training. In particular, patients affected by depression or chronic pain, as well as rehabilitating after stroke, can be treated at home with non-invasive electrical neuromodulation (transcranial Direct Current Stimulation, tDCS) in order to reduce daily travel expenses between home and hospital. Home monitoring of patient undergoing tDCS is essential to (1) optimize the stimulation parameters according to the current health status and to the stimulation outcomes, and (2) assess disease progression. However, monitoring effectiveness depends on the exchange of this information between the patient at home and his/her reference neurologist. Currently, the health IT scenario is composed by two independent environments, one dedicated to healthcare professionals (e.g., Electronic Health Records, EHRs), and one including mobile devices applications dedicated to citizens, caregivers and patients. Safety, communication and interoperability gaps prevented from an effective data exchange between these two environments. The aim of our work is to implement an integrated home monitoring system for tDCS patients, in which a web-based platform for EHR management exchanges data with a patient\u2019s mobile app

Widespread changes of white matter microstructure in obsessive-compulsive disorder: Effect of drug status.

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Initial Active Interrogation Experiments at The University of Michigan Linear Accelerator Laboratory

To support the mission of the Countering Weapons of Mass Destruction Office of the Department of Homeland Security, the Detection for Nuclear Nonproliferation group is researching active interrogation techniques and the development of new detection algorithms for fast neutron spectroscopy. The Countering Weapons of Mass Destruction Officehas loaned us a Varian M9 linear accelerator (linac), helium-3 detectors, boron-coated straw detectors, and perfluorocarbondetectors as part of this research, providing a variety of tools to conduct our experiments.In the summer of 2018, a thorough licensing process concluded, and preliminary experiments commenced. Later in the year, the facility was approved to possess and irradiate depleted uranium, which enabledus to conduct active interrogation experiments.In the fall of 2018, we conducted our first active interrogation measurements using the linac facility. The measurements used the linac to irradiate depleted uranium,lead, and tungsten targets to induce photonuclear reactions to emit fast neutrons. The neutrons were then detected using a simple helium-3 detector. Simulations were developed using MCNPX-PoliMi and MCNP 6.1 to validate the measured results. The simulations showed close agreement for depleted uranium but indicated that additional investigation is required for the lead and tungsten data. The facility will be indispensable as the researchprogressesbyproviding a mixed-radiation field consisting of fast neutrons and photons, which is similar to the radiation environment encountered in active interrogation scenarios.Additionally, the facility is involved inresearch related toradiation damage, dosimetry, and radiation-oncology.Future activities will involve characterization of photonuclear properties of various materials, and collaborations with other university researchers