475 research outputs found
Predicting the Next Best View for 3D Mesh Refinement
3D reconstruction is a core task in many applications such as robot
navigation or sites inspections. Finding the best poses to capture part of the
scene is one of the most challenging topic that goes under the name of Next
Best View. Recently, many volumetric methods have been proposed; they choose
the Next Best View by reasoning over a 3D voxelized space and by finding which
pose minimizes the uncertainty decoded into the voxels. Such methods are
effective, but they do not scale well since the underlaying representation
requires a huge amount of memory. In this paper we propose a novel mesh-based
approach which focuses on the worst reconstructed region of the environment
mesh. We define a photo-consistent index to evaluate the 3D mesh accuracy, and
an energy function over the worst regions of the mesh which takes into account
the mutual parallax with respect to the previous cameras, the angle of
incidence of the viewing ray to the surface and the visibility of the region.
We test our approach over a well known dataset and achieve state-of-the-art
results.Comment: 13 pages, 5 figures, to be published in IAS-1
Evaluation of Real-time Catch and Effort Reporting in the U.S. Ilex illecebrosus Fishery
The Illex illecebrosus fishery in the northwestern Atlantic Ocean is a trawl-based fishery. Illex illecebrosus normally lives less than one year, thus managing the fishery using a standard stock assessment approach is difficult. Real-time management is an attractive option. The purpose of this study was to investigate the validity and utility of data reported by commercial vessels for application in real-time management in the I. illecebrosus fishery. The assessment includes evaluating the frequency of erroneous reports, identifying the best measure of effort for catch per unit effort (CPUE) analysis, and examining the influence of vessel type and vessel behavior on subsequent analysis of trends in catch and effort.
Incomplete reports occurred 24% of the time in the commercial data. Misreported times and positions occurred less than 1% of the time. Searching time was not discriminated consistently. Searching times and distances were recovered from the more accurately-reported data on tow times and tow positions. Tow duration was more accurately estimated from Captains\u27 reports than tow distance. True distances were underestimated by 10-20% using the position of net deployment and retrieval to measure tow distance because tows did not follow a straight-line path. Effort could be estimated based on tow distance or tow duration. Duration was the most accurate effort term. Searches between tows did not improve subsequent catch. Similarly, overnight transits, arguably a type of searching behavior, did not improve the subsequent day\u27s catch. Thus, vessels, on the average, would have improved trip economics by not searching. Because of the apparent absence of a positive effect of searching and the lower accuracy of searching time and searching distance in comparison to tow-based metrics, particularly tow duration, addition of searching time or searching distance to effort did not materially improve the measurement of CPUE.
RSW (refrigerated seawater) trawlers search much less often than freezer trawlers. As a consequence of lower catch and longer duration tows, the CPUE for RSW trawlers is distinctly lower than for freezer trawlers. Catch per tow was higher by more than a factor of two for larger vessels. As a consequence of the higher catch and longer tows, CPUE was significantly higher also for the larger vessels. Managing the I. illecebrosus fishery using an industry-based reporting scheme would require information from freezer and RSW trawlers and specified vessel size categories
Are the dead taking over Facebook? A Big Data approach to the future of death online
We project the future accumulation of profiles belonging to deceased Facebook users. Our analysis suggests that a
minimum of 1.4 billion users will pass away before 2100 if Facebook ceases to attract new users as of 2018. If the
network continues expanding at current rates, however, this number will exceed 4.9 billion. In both cases, a majority of
the profiles will belong to non-Western users. In discussing our findings, we draw on the emerging scholarship on digital
preservation and stress the challenges arising from curating the profiles of the deceased. We argue that an exclusively
commercial approach to data preservation poses important ethical and political risks that demand urgent consideration.
We call for a scalable, sustainable, and dignified curation model that incorporates the interests of multiple stakeholders
Bringing dogs onto campus : inclusions and exclusions of animal bodies in organisations
Since the early years of the 20th century, work organizations have largely been places where animal bodies are absent or invisible. Recently, US and UK universities have facilitated therapy dog visits to improve students' wellbeing. In this article we analyse data on therapy dog visits to a UK university library as a starting point for thinking about other than human animals in organizations and the gendered dimensions of their inclusion and exclusion. Rather than focusing solely on the benefits of these encounters for students, we put the experiences of the dogs and their guardians centre stage, along with those of the library staff and the students. Drawing on observations of visits to a UK university library in 2015â2016, and a total of 16 interviews with library staff, guardians and students, we explore the instrumental rationale for the programme and the efforts to control any potential disruption of normative organizational expectations
Acute bilateral simultaneous angle closure glaucoma after topiramate administration: a case report
<p>Abstract</p> <p>Introduction</p> <p>A case of severe acute bilateral angle closure glaucoma with complete visual loss after oral topiramate therapy.</p> <p>Case presentation</p> <p>A 34 year-old woman developed bilateral severe visual loss 2 days after doubling the dosage of topiramate. Her best-corrected visual acuity (BCVA) was counting fingers in both eyes (OU). Intraocular pressures were 49 mm and 51 mm of Hg in right and left eyes respectively, with conjunctival chemosis, corneal edema, shallow anterior chamber and closed angles on gonioscopy. B-scan ultrasound revealed annular peripheral choroidal effusions in both eyes.</p> <p>Conclusion</p> <p>Intraocular pressures and anterior chamber depth were normalized after discontinuation of topiramate and initiation of antiglaucoma therapy. Two weeks later, visual acuities improved to 20/25 in the right eye and 20/40 in the left eye. B-scan ultrasound showed resolution of choroidal effusion. Topiramate, an oral sulpha-derivative medication is known to cause ciliochoroidal effusions, which lead to forward rotation of the ciliary body and displacement of the lens-iris diaphragm, with resultant acute angle closure glaucoma and myopic shift.</p
DETERMINATION OF TYPES OF INDIVIDUALS IN APHIDS, ROTIFERS AND CLADOCERA 1
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72827/1/j.1469-185X.1929.tb00888.x.pd
Observation of the Dynamic Beta Effect at CESR with CLEO
Using the silicon strip detector of the CLEO experiment operating at the
Cornell Electron-positron Storage Ring (CESR), we have observed that the
horizontal size of the luminous region decreases in the presence of the
beam-beam interaction from what is expected without the beam-beam interaction.
The dependence on the bunch current agrees with the prediction of the dynamic
beta effect. This is the first direct observation of the effect.Comment: 9 page uuencoded postscript file, postscritp file also available
through http://w4.lns.cornell.edu/public/CLNS, submitted to Phys. Rev.
The macro-and micro-fossil record of the Cambrian priapulid Ottoia
The stem-group priapulid Ottoia Walcott, 1911, is the most abundant worm in the mid-Cambrian Burgess Shale, but has not been unambiguously demonstrated elsewhere. High-resolution electron and optical microscopy of macroscopic Burgess Shale specimens reveals the detailed anatomy of its robust hooks, spines and pharyngeal teeth, establishing the presence of two species: Ottoia prolifica Walcott, 1911, and Ottoia tricuspida sp. nov. Direct comparison of these sclerotized elements with a suite of shale-hosted mid-to-late Cambrian microfossils extends the range of ottoiid priapulids throughout the middle to upper Cambrian strata of the Western Canada Sedimentary Basin. Ottoiid priapulids represented an important component of Cambrian ecosystems: they occur in a range of lithologies and thrived in shallow water as well as in the deep-water setting of the Burgess Shale. A wider survey of Burgess Shale macrofossils reveals specific characters that diagnose priapulid sclerites more generally, establishing the affinity of a wide range of Small Carbonaceous Fossils and demonstrating the prominent role of priapulids in Cambrian seas
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