247 research outputs found
A computer program for hydrostatic bearings including the effects of non-uniform film thickness and relative velocity for various methods of lubricant supply final technical report
Computer program for hydrostatic bearing - effects of nonuniform film thickness and lubricant suppl
PIM: Video Coding using Perceptual Importance Maps
Human perception is at the core of lossy video compression, with numerous
approaches developed for perceptual quality assessment and improvement over the
past two decades. In the determination of perceptual quality, different
spatio-temporal regions of the video differ in their relative importance to the
human viewer. However, since it is challenging to infer or even collect such
fine-grained information, it is often not used during compression beyond
low-level heuristics. We present a framework which facilitates research into
fine-grained subjective importance in compressed videos, which we then utilize
to improve the rate-distortion performance of an existing video codec (x264).
The contributions of this work are threefold: (1) we introduce a web-tool which
allows scalable collection of fine-grained perceptual importance, by having
users interactively paint spatio-temporal maps over encoded videos; (2) we use
this tool to collect a dataset with 178 videos with a total of 14443 frames of
human annotated spatio-temporal importance maps over the videos; and (3) we use
our curated dataset to train a lightweight machine learning model which can
predict these spatio-temporal importance regions. We demonstrate via a
subjective study that encoding the videos in our dataset while taking into
account the importance maps leads to higher perceptual quality at the same
bitrate, with the videos encoded with importance maps preferred
over the baseline videos. Similarly, we show that for the 18 videos in test
set, the importance maps predicted by our model lead to higher perceptual
quality videos, preferred over the baseline at the same bitrate
Description of the last-instar larva of Zenithoptera lanei Santos, 1941 (Odonata: Libellulidae)
The larva of Zenithoptera lanei Santos, 1941 is described and illustrated based on three exuviae of reared larvae collected in Misiones, Argentina, Roraima and Amazonas, Brazil. A comparison with the larva of Z. anceps Pujol-Luz, 1993 is included.Fil: Rippel, Camila Gisel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Posadas; ArgentinaFil: Neiss, Ulisses G.. Instituto de CriminalĂstica; BrasilFil: del Palacio, Alejandro. Universidad Nacional de Avellaneda; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Schröder, Noelia Malena. Universidad Nacional de Misiones. Facultad de Cs.exactas QuĂmicas y Naturales. Departamento de BioquĂmica Clinica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; ArgentinaFil: Fleck, GĂĽnther. Instituto Nacional de Pesquisas da AmazĂ´nia; BrasilFil: Hamada, Neusa. Instituto Nacional de Pesquisas da AmazĂ´nia; BrasilFil: Marti, Dardo Andrea. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Posadas; ArgentinaFil: Schweigmann, Nicolás J.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de EcologĂa, GenĂ©tica y EvoluciĂłn; Argentin
The Medical Segmentation Decathlon
International challenges have become the de facto standard for comparative
assessment of image analysis algorithms given a specific task. Segmentation is
so far the most widely investigated medical image processing task, but the
various segmentation challenges have typically been organized in isolation,
such that algorithm development was driven by the need to tackle a single
specific clinical problem. We hypothesized that a method capable of performing
well on multiple tasks will generalize well to a previously unseen task and
potentially outperform a custom-designed solution. To investigate the
hypothesis, we organized the Medical Segmentation Decathlon (MSD) - a
biomedical image analysis challenge, in which algorithms compete in a multitude
of both tasks and modalities. The underlying data set was designed to explore
the axis of difficulties typically encountered when dealing with medical
images, such as small data sets, unbalanced labels, multi-site data and small
objects. The MSD challenge confirmed that algorithms with a consistent good
performance on a set of tasks preserved their good average performance on a
different set of previously unseen tasks. Moreover, by monitoring the MSD
winner for two years, we found that this algorithm continued generalizing well
to a wide range of other clinical problems, further confirming our hypothesis.
Three main conclusions can be drawn from this study: (1) state-of-the-art image
segmentation algorithms are mature, accurate, and generalize well when
retrained on unseen tasks; (2) consistent algorithmic performance across
multiple tasks is a strong surrogate of algorithmic generalizability; (3) the
training of accurate AI segmentation models is now commoditized to non AI
experts
Risk accelerators in disasters : insights from the typhoon Haiyan response on humanitarian information management and decision support
Published version of a chapter in the book: Advanced Information Systems Engineering. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-319-07881-6_2Modern societies are increasingly threatened by disasters that require rapid response through ad-hoc collaboration among a variety of actors and organizations. The complexity within and across today's societal, economic and environmental systems defies accurate predictions and assessments of damages, humanitarian needs, and the impact of aid. Yet, decision-makers need to plan, manage and execute aid response under conditions of high uncertainty while being prepared for further disruptions and failures. This paper argues that these challenges require a paradigm shift: instead of seeking optimality and full efficiency of procedures and plans, strategies should be developed that enable an acceptable level of aid under all foreseeable eventualities. We propose a decision- and goal-oriented approach that uses scenarios to systematically explore future developments that may have a major impact on the outcome of a decision. We discuss to what extent this approach supports robust decision-making, particularly if time is short and the availability of experts is limited. We interlace our theoretical findings with insights from experienced humanitarian decision makers we interviewed during a field research trip to the Philippines in the aftermath of Typhoon Haiyan
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