9,590 research outputs found
Vector potential methods
Vector potential and related methods, for the simulation of both inviscid and viscous flows over aerodynamic configurations, are briefly reviewed. The advantages and disadvantages of several formulations are discussed and alternate strategies are recommended. Scalar potential, modified potential, alternate formulations of Euler equations, least-squares formulation, variational principles, iterative techniques and related methods, and viscous flow simulation are discussed
Online Visual Robot Tracking and Identification using Deep LSTM Networks
Collaborative robots working on a common task are necessary for many
applications. One of the challenges for achieving collaboration in a team of
robots is mutual tracking and identification. We present a novel pipeline for
online visionbased detection, tracking and identification of robots with a
known and identical appearance. Our method runs in realtime on the limited
hardware of the observer robot. Unlike previous works addressing robot tracking
and identification, we use a data-driven approach based on recurrent neural
networks to learn relations between sequential inputs and outputs. We formulate
the data association problem as multiple classification problems. A deep LSTM
network was trained on a simulated dataset and fine-tuned on small set of real
data. Experiments on two challenging datasets, one synthetic and one real,
which include long-term occlusions, show promising results.Comment: IEEE/RSJ International Conference on Intelligent Robots and Systems
(IROS), Vancouver, Canada, 2017. IROS RoboCup Best Paper Awar
Numerical solution of transonic full stream function equations in conservation form
The stream function equation in conservation form is solved iteratively based on the artificial compressibility method. The density is not a unique function of the mass flux. In order to avoid the ambiguity near the sonic line, the density is updated in terms of the velocity, which is obtained through a simple integration of a first order equation step by step in the flow field. Iteration algorithms and finite difference approximations are discussed and numerical results of both conservative and nonconservative calculations are presented
Avian Adenoviruses Infections with Special Attention to Inclusion Body Hepatitis/ Hydropericardium Syndrome and Egg Drop Syndrome
The first avian adenovirus (AAV) associated with clinical disease was isolated
from an outbreak of respiratory disease in quail in 1950 (Olson, 1950). Since
that time, AAVs have been found in all types and breeds of chickens and from a
variety of other avian species. The infections may be asymptomatic or
associated with several clinical and pathological conditions. Vertical
transmission via the egg is the most common way of transmission. Also
horizontal transmission through faeces, contaminated egg trays, crates and
trucks play a role in the infection route. Studies have demonstrated the
presence of antibodies in healthy poultry, and viruses have been isolated from
normal birds. Avian adenoviruses in chickens are the etiological agents of 2
diseases known as inclusion body hepatitis (IBH) and hydropericardium syndrome
(HP). In some cases each condition is observed separately, however, recently
the 2 conditions have frequently been observed as a single entity; therefore,
the name hepatitis hydropericardium has been widely used to describe the
pathologic condition. The syndrome is an acute disease of young chickens
associated with anemia, haemorrhagic disorders, hydropericardium and high
mortality. Egg-Drop-Syndrome (EDS) is caused also by an adenovirus. The
disease is characterised by a severe drop in egg production as well as the
production of shell-less, thin-shelled, discoloured or misshapen eggs in
apparently healthy birds. Ducks and geese are the natural host of the EDS
virus. It was first described in chickens in the 1970s and spread to several
countries world wide. The birds usually do not show any other signs of
disease, and mortality is not expected. There is no specific treatment of the
AAV infections. Active immunization by vaccination using an inactivated is
wide spread
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