180 research outputs found
Transformer Networks for Trajectory Forecasting
Most recent successes on forecasting the people motion are based on LSTM
models and all most recent progress has been achieved by modelling the social
interaction among people and the people interaction with the scene. We question
the use of the LSTM models and propose the novel use of Transformer Networks
for trajectory forecasting. This is a fundamental switch from the sequential
step-by-step processing of LSTMs to the only-attention-based memory mechanisms
of Transformers. In particular, we consider both the original Transformer
Network (TF) and the larger Bidirectional Transformer (BERT), state-of-the-art
on all natural language processing tasks. Our proposed Transformers predict the
trajectories of the individual people in the scene. These are "simple" model
because each person is modelled separately without any complex human-human nor
scene interaction terms. In particular, the TF model without bells and whistles
yields the best score on the largest and most challenging trajectory
forecasting benchmark of TrajNet. Additionally, its extension which predicts
multiple plausible future trajectories performs on par with more engineered
techniques on the 5 datasets of ETH + UCY. Finally, we show that Transformers
may deal with missing observations, as it may be the case with real sensor
data. Code is available at https://github.com/FGiuliari/Trajectory-Transformer.Comment: 18 pages, 3 figure
The Spectrum of Fundus Autofluorescence Findings in Birdshot Chorioretinopathy
Objective. To describe the diverse patterns observed with the use of autofluorescence fundus photography (FAF) in patients with Birdshot chorioretinopathy (BSCR). Methods. A chart review of patients with BSCR seen at the Massachusetts Eye Research and Surgery Institution, who had autofluorescence fundus photography. The data obtained included age, gender, presence of the HLA-A29 haplotype, and current treatment. Results. Eighteen eyes with HLA-A29 associated BSCR were included. Four eyes presented with active inflammation. Correspondence of the lesions noted in the colour fundus photograph was observed in 3 eyes which were more easily identified with the FAF. Fifteen eyes had fundus lesions more numerous and evident in the FAF than in the colour fundus photograph.
Conclusion. Because FAF testing provides valuable insight into the metabolic state of the PR/RPE-complex, it may serve as a useful noninvasive assessment tool in patients with posterior uveitis in which the outer retina-RPE-choriocapillaries-complex is involved
GMA: A Pareto Optimal Distributed Resource-Allocation Algorithm
To address the rising demand for strong packet delivery guarantees in
networking, we study a novel way to perform graph resource allocation. We first
introduce allocation graphs, in which nodes can independently set local
resource limits based on physical constraints or policy decisions. In this
scenario we formalize the distributed path-allocation (PAdist) problem, which
consists in allocating resources to paths considering only local on-path
information -- importantly, not knowing which other paths could have an
allocation -- while at the same time achieving the global property of never
exceeding available resources.
Our core contribution, the global myopic allocation (GMA) algorithm, is a
solution to this problem. We prove that GMA can compute unconditional
allocations for all paths on a graph, while never over-allocating resources.
Further, we prove that GMA is Pareto optimal with respect to the allocation
size, and it has linear complexity in the input size. Finally, we show with
simulations that this theoretical result could be indeed applied to practical
scenarios, as the resulting path allocations are large enough to fit the
requirements of practically relevant applications
Orbital Burkitt's Lymphoma: An Aggressive Presentation
Objective. To present the case of an aggressive orbital Burkitt's lymphoma.
Methods. Chart review. Case Presentation. A 24-year-old Haitian man came to our clinic complaining of rapidly progressive right eye proptosis. On examination, a large friable exophytic mass with necrotic areas and exudative/hemorrhagic secretions was noted protruding from his right orbit. A biopsy revealed the characteristic “starry-sky” appearance of a Burkitt lymphoma. The patient died shortly after due to complications from systemic involvement. Discussion. This case is meant to raise physicians' awareness on the healthcare situation in some underdeveloped countries, emphasizing the importance of education in preventive medicine
Presumed Sturge Weber Syndrome in a Haitian Boy: A Case of Delayed Diagnosis
Purpose. To report an untypical presentation of a presumed Sturge-Weber Syndrome (SWS), and to highlight the indispensable value of thorough clinical examination as primary means for proper diagnosis and management. Methods. Chart review. Results. A 7 year-old boy, with a long history of ocular symptoms and an unspecified ocular surgery, presents with a painful blind left eye. Based on clinical examination, the suspicion of SWS was raised. The presentation was not typical in the sense that no evident port-wine stain was observed on the face. However, facial asymmetry and gum discoloration were guiding clinical clues to pursue further investigations. Unfortunately, due to poor treatment response, the patient underwent enucleation. Tissue pathology revealed diffuse choroidal hemangiomas, consistent with the diagnosis of SWS. Conclusion. SWS presents with hamartomatous malformations and venous dilation affecting the skin, central nervous system and eye. The ocular involvement may vary, with the most common complications being glaucoma, buphthalmos and diffuse choroidal hemangiomas. This case report helps remind physicians of the importance of a thorough clinical examination, and highlights the ophthalmologists' responsibility of examining beyond the eye
Leveraging commonsense for object localisation in partial scenes
We propose an end-to-end solution to address the problem of object
localisation in partial scenes, where we aim to estimate the position of an
object in an unknown area given only a partial 3D scan of the scene. We propose
a novel scene representation to facilitate the geometric reasoning, Directed
Spatial Commonsense Graph (D-SCG), a spatial scene graph that is enriched with
additional concept nodes from a commonsense knowledge base. Specifically, the
nodes of D-SCG represent the scene objects and the edges are their relative
positions. Each object node is then connected via different commonsense
relationships to a set of concept nodes. With the proposed graph-based scene
representation, we estimate the unknown position of the target object using a
Graph Neural Network that implements a novel attentional message passing
mechanism. The network first predicts the relative positions between the target
object and each visible object by learning a rich representation of the objects
via aggregating both the object nodes and the concept nodes in D-SCG. These
relative positions then are merged to obtain the final position. We evaluate
our method using Partial ScanNet, improving the state-of-the-art by 5.9% in
terms of the localisation accuracy at a 8x faster training speed.Comment: arXiv admin note: text overlap with arXiv:2203.0538
Hummingbird: A Flexible and Lightweight Inter-Domain Bandwidth-Reservation System
The current Internet lacks a bandwidth-reservation infrastructure that
enables fine-grained inter-domain reservations for end hosts. This is hindering
the provisioning of quality-of-service guarantees for real-time applications
like video calls and gaming, cloud-based systems, financial transactions,
telesurgery, and other remote applications that benefit from reliable
communication. This paper introduces Hummingbird, a novel lightweight
inter-domain bandwidth-reservation system that addresses several shortcomings
of previous designs.
Hummingbird supports flexible and composable reservations and enables
end-to-end guarantees without requiring autonomous systems to manage
reservations for their endhosts. Previous systems tied reservations to
autonomous-system numbers or network addresses, which limits the flexibility of
reservations. In contrast, our system decouples reservations from network
identities and, as a result, the control plane from the data plane. This design
choice facilitates multiple co-existing control-plane mechanisms and enables
innovative approaches, such as a control plane based on blockchain smart
contracts that offers tradeable bandwidth-reservation assets and end-to-end
guarantees. The data-plane design ensures simplicity for efficient processing
on border routers, which streamlines implementation, deployment, and traffic
policing while maintaining robust security properties.Comment: 14 pages, 7 figure
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