Ellipsis Resolution as Question Answering: An Evaluation

Most, if not all forms of ellipsis (e.g., so does Mary) are similar to reading comprehension questions (what does Mary do), in that in order to resolve them, we need to identify an appropriate text span in the preceding discourse. Following this observation, we present an alternative approach for English ellipsis resolution relying on architectures developed for question answering (QA). We present both single-task models, and joint models trained on auxiliary QA and coreference resolution datasets, clearly outperforming the current state of the art for Sluice Ellipsis (from 70.00 to 86.01 F1) and Verb Phrase Ellipsis (from 72.89 to 78.66 F1).Comment: To appear in EACL 202

Net Returns for Grain Sorghum and Corn under Alternative Irrigation Systems in Western Kansas

This study evaluates seven irrigation systems for use in production of grain sorghum and corn. These systems are medium pressure center-pivot (MPCP), low pressure center-pivot (LPCP), low drift nozzle center-pivot (LDN) , low energy precision application center-pivot (LEPA), furrow flood (FF) , surge flood (SF), and subsurface drip (SD). After-tax net present value estimates from investing in and using each system over a 10-year period to produce grain sorghum and corn are compared. The surge flood system, has the highest net returns under typical conditions for irrigation of both grain sorghum and corn. The furrow flood system generates the next highest net returns for both crops, followed by the subsurface drip system. The medium pressure center-pivot system is the least profitable for both crops. Of the center-pivot systems, the low pressure system has the highest net return, but is followed very closely by the low drift nozzle system. The results of the sensitivity analysis indicate that the net return estimates and ranking of the subsurface drip system are very sensitive to the yield response to irrigation. Lower than average crop prices also have a substantial impact on the ranking of this system. The original investment cost is also an important determinant of its net return.Crop Production/Industries,

Compositional Generalization in Image Captioning

Image captioning models are usually evaluated on their ability to describe a held-out set of images, not on their ability to generalize to unseen concepts. We study the problem of compositional generalization, which measures how well a model composes unseen combinations of concepts when describing images. State-of-the-art image captioning models show poor generalization performance on this task. We propose a multi-task model to address the poor performance, that combines caption generation and image--sentence ranking, and uses a decoding mechanism that re-ranks the captions according their similarity to the image. This model is substantially better at generalizing to unseen combinations of concepts compared to state-of-the-art captioning models.Comment: To appear at CoNLL 2019, EMNL

Fast Radiometric Compensation for Nonlinear Projectors

Radiometric compensation can be accomplished on nonlinearprojector-camera systems through the use of pixelwise lookup ta-bles. Existing methods are both computationally and memory inten-sive. Such methods are impractical to be implemented for currenthigh-end projector technology. In this paper, a novel computation-ally efficient method for nonlinear radiometric compensation of pro-jectors is proposed. The compensation accuracy of the proposedmethod is assessed with the use of a spectroradiometer. Experi-mental results show both the effectiveness of the method and thereduction in compensation time compared to a recent state-of-the-art method

Constraints for Time-Multiplexed Structured Light with a Hand-held Camera

Multi-frame structured light in projector-camera systems affords high-density and non-contact methods of 3D surface reconstruction. However, they have strict setup constraints which can become expensive and time-consuming. Here, we investigate the conditions under which a projective homography can be used to compensate for small perturbations in pose caused by a hand-held camera. We synthesize data using a pinhole camera model and use it to determine the average 2D reprojection error per point correspondence. This error map is grouped into regions with specified upper-bounds to classify which regions produce sufficiently minimal error to be considered feasible for a structured-light projector-camera system with a hand-held camera. Empirical results demonstrate that a sub-pixel reprojection accuracy is achievable with a feasible geometric constraint

Public space in an age of austerity

Through an overview of the decade 2008 to 2017, and looking comparatively across four northern European cities, this paper reflects on the changing nature of public space during these austerity years and on the processes of shaping public spaces. The paper draws from the experiences of London, Copenhagen, Malmo and Oslo to explore processes of the design, development, use and management of public spaces during this period. The evidence suggests that we have witnessed a period of significant innovation, side by side with major challenges to the collective approach to public spaces. This has led to distinct forms of public spaces that for good or ill have multiplied as a result of the trends discussed in the paper, spaces of; expectation; the private/public sphere; spectacle; respite; infrastructure; diversion; income generation; security; the ephemeral city; community control; occupation; disadvantage; and decline. Episodes of changing practice are set out in the paper and cumulatively reveal distinct and significant changes during the austerity era, although not necessarily in the manner that might have been expected. Instead, in these four cities, the impact of austerity seems to have been eclipsed by other evolving and competing public policy goals, and by the evolving range of public space types