Attentive Learning of Sequential Handwriting Movements: A Neural Network Model

Defense Advanced research Projects Agency and the Office of Naval Research (N00014-95-1-0409, N00014-92-J-1309); National Science Foundation (IRI-97-20333); National Institutes of Health (I-R29-DC02952-01)

Untyped Recursion Schemes and Infinite Intersection Types

Abstract. A new framework for higher-order program verification has been recently proposed, in which higher-order functional programs are modelled as higher-order recursion schemes and then model-checked. As recursion schemes are essentially terms of the simply-typed lambda-calculus with recursion and tree constructors, however, it was not clear how the new framework applies to programs written in languages with more advanced type systems. To circumvent the limitation, this paper introduces an untyped version of recursion schemes and develops an in-finite intersection type system that is equivalent to the model checking of untyped recursion schemes, so that the model checking can be re-duced to type checking as in recent work by Kobayashi and Ong for typed recursion schemes. The type system is undecidable but we can obtain decidable subsets of the type system by restricting the shapes of intersection types, yielding a sound (but incomplete in general) model checking algorithm.

Field Measurements of Terrestrial and Martian Dust Devils

Surface-based measurements of terrestrial and martian dust devils/convective vortices provided from mobile and stationary platforms are discussed. Imaging of terrestrial dust devils has quantified their rotational and vertical wind speeds, translation speeds, dimensions, dust load, and frequency of occurrence. Imaging of martian dust devils has provided translation speeds and constraints on dimensions, but only limited constraints on vertical motion within a vortex. The longer mission durations on Mars afforded by long operating robotic landers and rovers have provided statistical quantification of vortex occurrence (time-of-sol, and recently seasonal) that has until recently not been a primary outcome of more temporally limited terrestrial dust devil measurement campaigns. Terrestrial measurement campaigns have included a more extensive range of measured vortex parameters (pressure, wind, morphology, etc.) than have martian opportunities, with electric field and direct measure of dust abundance not yet obtained on Mars. No martian robotic mission has yet provided contemporaneous high frequency wind and pressure measurements. Comparison of measured terrestrial and martian dust devil characteristics suggests that martian dust devils are larger and possess faster maximum rotational wind speeds, that the absolute magnitude of the pressure deficit within a terrestrial dust devil is an order of magnitude greater than a martian dust devil, and that the time-of-day variation in vortex frequency is similar. Recent terrestrial investigations have demonstrated the presence of diagnostic dust devil signals within seismic and infrasound measurements; an upcoming Mars robotic mission will obtain similar measurement types

Managing the whole landscape: historical, hybrid, and novel ecosystems

The reality confronting ecosystem managers today is one of heterogeneous, rapidly transforming landscapes, particularly in the areas more affected by urban and agricultural development. A landscape management framework that incorporates all systems, across the spectrum of degrees of alteration, provides a fuller set of options for how and when to intervene, uses limited resources more effectively, and increases the chances of achieving management goals. That many ecosystems have departed so substantially from their historical trajectory that they defy conventional restoration is not in dispute. Acknowledging novel ecosystems need not constitute a threat to existing policy and management approaches. Rather, the development of an integrated approach to management interventions can provide options that are in tune with the current reality of rapid ecosystem change

Reporting of methods for automated devices: A systematic review and recommendation for studies using FlowCam for phytoplankton

Accurate and detailed reporting of methods is essential for scientific progress, yet it is widely accepted that authors across all scientific fields tend to provide insufficient methods detail. Given the recent proliferation of automated and semi-automated technologies for data collection, to address this widespread issue the details needed for interpretation and reproducibility for each specific technique first need to be identified. A systematic literature review assessed the comprehensiveness of method details reported by 116 peer-reviewed studies published between 2017 and 2020 using the FlowCam (a widely used imaging flow cytometer) to image phytoplankton, finding all to be lacking in critical details, inhibiting reproducibility, and limiting the veracity of some findings. Through this review and three case studies, we identify several key method details that should be reported by FlowCam studies to ensure their findings are credible, comparable, and replicable and illustrate the wide-reaching implications for not doing so. Future studies using FlowCam for phytoplankton analyses should ensure clear reporting of all relevant details relating to the FlowCam unit, sample preparation, run settings, post-processing of images, and the considered use of only verified measurement outputs. A methods reporting template is presented as a guideline intended to enhance the quality, interpretability, and repeatability of future FlowCam papers. The pervasiveness of inadequacies in FlowCam methods reporting identified here highlights how vital it is for users of any automated or semi-automated scientific technologies to have a clear understanding of the impact of all method details on their findings, and to report these details adequately