9,222 research outputs found
Domain Adaptive Neural Networks for Object Recognition
We propose a simple neural network model to deal with the domain adaptation
problem in object recognition. Our model incorporates the Maximum Mean
Discrepancy (MMD) measure as a regularization in the supervised learning to
reduce the distribution mismatch between the source and target domains in the
latent space. From experiments, we demonstrate that the MMD regularization is
an effective tool to provide good domain adaptation models on both SURF
features and raw image pixels of a particular image data set. We also show that
our proposed model, preceded by the denoising auto-encoder pretraining,
achieves better performance than recent benchmark models on the same data sets.
This work represents the first study of MMD measure in the context of neural
networks
ALMA Science Verification Data: Millimeter Continuum Polarimetry of the Bright Radio Quasar 3C 286
We present full-polarization observations of the compact, steep-spectrum
radio quasar 3C~286 made with the ALMA at 1.3~mm. These are the first
full-polarization ALMA observations, which were obtained in the framework of
Science Verification. A bright core and a south-west component are detected in
the total intensity image, similar to previous centimeter images. Polarized
emission is also detected toward both components. The fractional polarization
of the core is about 17\%, this is higher than the fractional polarization at
centimeter wavelengths, suggesting that the magnetic field is even more ordered
in the millimeter radio core than it is further downstream in the jet. The
observed polarization position angle (or EVPA) in the core is
\,, which confirms the trend that the EVPA slowly increases
from centimeter to millimeter wavelengths. With the aid of multi-frequency VLBI
observations, we argue that this EVPA change is associated with the
frequency-dependent core position. We also report a serendipitous detection of
a sub-mJy source in the field of view, which is likely to be a submillimeter
galaxy.Comment: 10 pages, 9 figures, Accepted for publication in the Ap
Hot Core, Outflows and Magnetic Fields in W43-MM1 (G30.79 FIR 10)
We present submillimeter spectral line and dust continuum polarization
observations of a remarkable hot core and multiple outflows in the high-mass
star-forming region W43-MM1 (G30.79 FIR 10), obtained using the Submillimeter
Array (SMA). A temperature of 400 K is estimated for the hot-core using
CHCN (J=19-18) lines, with detections of 11 K-ladder components. The high
temperature and the mass estimates for the outflows indicate high-mass
star-formation. The continuum polarization pattern shows an ordered
distribution, and its orientation over the main outflow appears aligned to the
outflow. The derived magnetic field indicates slightly super-critical
conditions. While the magnetic and outflow energies are comparable, the B-field
orientation appears to have changed from parsec scales to 0.1 pc scales
during the core/star-formation process.Comment: accepted, ApJ Letter
Dinámica del nitrógeno mineral y la biota edáfica durante la descomposición de enmiendas orgánicas en un ambiente semiárido
El uso de leguminosas como abonos verdes, puede proveer una cantidad importante de nitrógeno para el cultivo posterior, dependiendo de la velocidad de descomposición de los residuos. La necesidad de siembra directa (SD) en los suelos frágiles no permite el enterramiento de los residuos, dificultando su descomposición y la liberación de nitrógeno inorgánico (Ni). En este trabajo se estudió la relación entre descomposición de abonos verdes de vicia con y sin adición de estiércol, la liberación de Ni y la dinámica de las poblaciones microbianas asociadas a estos procesos en el semiárido de la provincia de San Luis, Argentina. En macetas con suelo de la región se incubó suelo solo, dos dosis de vicia y dos dosis de vicia+estiércol durante un año en condiciones reales de temperatura y humedad. Bolsas conteniendo residuos de planta entera de vicia con y sin estiércol fueron ubicadas en superficie (simulando SD) y a 10 cm de profundidad (simulando una labranza mínima) en el suelo de las macetas. Se tomaron muestras de suelo para medir Ni (Nitratos y Amonio) y grupos funcionales microbianos (amonificantes, nitrificantes y celulolíticos). Al mismo tiempo, se retiraron bolsas para medir la velocidad de descomposición del residuo. El contenido de amonio en el suelo aumentó en 6,7 (D1), 28 (D2), 7,3 (D3) y 26 (D4) mg/Kg en un año; por otra parte, el contenido de nitratos aumentó 17 (D1), 32 (D2), 23 (D3) y 41 (D4) mg/Kg. El aumento en el contenido de Ni coincidió con la evolución de las poblaciones de microorganismos amonificantes y nitrificantes. La descomposición en los residuos enterrados (p una importante cantidad de Ni en el primer año (aún en presencia del estiércol que influye en los equilibrios de mineralización inmovilización por su alta relación C/N), pero para su mayor disponibilidad es recomendable realizar una labranza minim
RACIAL DISCRIMINATION IN HIRE/PURCHASE LENDING IN APARTHEID SOUTH AFRICA
A partial-observability model finds evidence of racial discrimination by retailers of consumer durables in apartheid South Africa. In particular, black households are 13 percentage points more likely to demand a hire/purchase loan but not to have one supplied than are other households, all else equal.Consumer finance, disequilibrium models, racial discrimination, truncated and censored models, South Africa, Financial Economics,
Dynamical Synapses Enhance Neural Information Processing: Gracefulness, Accuracy and Mobility
Experimental data have revealed that neuronal connection efficacy exhibits
two forms of short-term plasticity, namely, short-term depression (STD) and
short-term facilitation (STF). They have time constants residing between fast
neural signaling and rapid learning, and may serve as substrates for neural
systems manipulating temporal information on relevant time scales. The present
study investigates the impact of STD and STF on the dynamics of continuous
attractor neural networks (CANNs) and their potential roles in neural
information processing. We find that STD endows the network with slow-decaying
plateau behaviors-the network that is initially being stimulated to an active
state decays to a silent state very slowly on the time scale of STD rather than
on the time scale of neural signaling. This provides a mechanism for neural
systems to hold sensory memory easily and shut off persistent activities
gracefully. With STF, we find that the network can hold a memory trace of
external inputs in the facilitated neuronal interactions, which provides a way
to stabilize the network response to noisy inputs, leading to improved accuracy
in population decoding. Furthermore, we find that STD increases the mobility of
the network states. The increased mobility enhances the tracking performance of
the network in response to time-varying stimuli, leading to anticipative neural
responses. In general, we find that STD and STP tend to have opposite effects
on network dynamics and complementary computational advantages, suggesting that
the brain may employ a strategy of weighting them differentially depending on
the computational purpose.Comment: 40 pages, 17 figure
Food healthy knowledge, attitudes and practices: Survey of the general public and food handlers
AbstractModifying the energy content of foods, particularly foods eaten away from home, is important in addressing the obesity epidemic. Food handlers in the restaurant industry are uniquely placed to influence the provision of reduced-calorie foods, but little is known about their opinions on this issue. The objectives of the present study were to determine the general public and food handlers׳ knowledge and opinions, issues and barriers related to providing these items on the menu, and about the influence of the calorie content of restaurant items on customer intake. The food handlers surveyed had a significantly lower food science knowledge score than the general public. There was significant difference between the scores of food handlers and general public (t=3.5108, df=177.743, P-value=0.0005). The majority of respondents ranked taste as the most influential factor in the success of reduced-calorie items (p<0.0028). The results of this survey indicate that opportunities exist for reducing the energy content of restaurant items. Ongoing collaboration is needed between food handlers and public health professionals to ensure that appealing reduced-calorie menu items are more widely available in restaurants and that research is directed towards effective ways to develop and promote these items
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