606 research outputs found
Catalyst Development for Higher Alcohol Synthesis (HAS)
This study investigated the effects of partial substitution at the A- and/or B-site of LaCoO3 perovskite catalysts (ABO3) on higher alcohol synthesis (HAS) from syngas. The catalyst properties and catalytic performances were well studied for the La1-xSrxCo1-y-zNiyCuzO3 catalysts. A-site substitution affected CO conversion, while B-site substitution affected higher alcohol selectivity. The effects of alkali promoters and reaction conditions were also discussed. This study proved that partially-substituted perovskites are promising candidates for the enhancement of HAS
Field-aware Calibration: A Simple and Empirically Strong Method for Reliable Probabilistic Predictions
It is often observed that the probabilistic predictions given by a machine
learning model can disagree with averaged actual outcomes on specific subsets
of data, which is also known as the issue of miscalibration. It is responsible
for the unreliability of practical machine learning systems. For example, in
online advertising, an ad can receive a click-through rate prediction of 0.1
over some population of users where its actual click rate is 0.15. In such
cases, the probabilistic predictions have to be fixed before the system can be
deployed.
In this paper, we first introduce a new evaluation metric named field-level
calibration error that measures the bias in predictions over the sensitive
input field that the decision-maker concerns. We show that existing post-hoc
calibration methods have limited improvements in the new field-level metric and
other non-calibration metrics such as the AUC score. To this end, we propose
Neural Calibration, a simple yet powerful post-hoc calibration method that
learns to calibrate by making full use of the field-aware information over the
validation set. We present extensive experiments on five large-scale datasets.
The results showed that Neural Calibration significantly improves against
uncalibrated predictions in common metrics such as the negative log-likelihood,
Brier score and AUC, as well as the proposed field-level calibration error.Comment: WWW 202
Effective Vortex Mass from Microscopic Theory
We calculate the effective mass of a single quantized vortex in the BCS
superconductor at finite temperature. Based on effective action approach, we
arrive at the effective mass of a vortex as integral of the spectral function
divided by over frequency. The spectral function is
given in terms of the quantum-mechanical transition elements of the gradient of
the Hamiltonian between two Bogoliubov-deGennes (BdG) eigenstates. Based on
self-consistent numerical diagonalization of the BdG equation we find that the
effective mass per unit length of vortex at zero temperature is of order (=Fermi momentum, =coherence length), essentially
equaling the electron mass displaced within the coherence length from the
vortex core. Transitions between the core states are responsible for most of
the mass. The mass reaches a maximum value at and decreases
continuously to zero at .Comment: Supercedes prior version, cond-mat/990312
CREB activity maintains the survival of cingulate cortical pyramidal neurons in the adult mouse brain
Cyclic AMP-responsive element binding protein (CREB) activity is known to contribute to important neuronal functions, such as synaptic plasticity, learning and memory. Using a microelectroporation technique to overexpress dominant negative mutant CREB (mCREB) in the adult mouse brain, we found that overexpression of mCREB in the forebrain cortex induced neuronal degeneration. Our findings suggest that constitutively active CREB phosphorylation is important for the survival of mammalian cells in the brain
An Effective Way of J Wave Separation Based on Multilayer NMF
J wave is getting more and more important in the clinical diagnosis as a new index of the electrocardiogram (ECG) of ventricular bipolar, but its signal often mixed in normal ST segment, using the traditional electrocardiograph, and diagnosed by experience cannot meet the practical requirements. Therefore, a new method of multilayer nonnegative matrix factorization (NMF) in this paper is put forward, taking the hump shape J wave, for example, which can extract the original J wave signal from the ST segment and analyze the accuracy of extraction, showing the characteristics of hump shape J wave from the aspects of frequency domain, power spectrum, and spectral type, providing the basis for clinical diagnosis and increasing the reliability of the diagnosis of J wave
Salient Object Detection in RGB-D Videos
Given the widespread adoption of depth-sensing acquisition devices, RGB-D
videos and related data/media have gained considerable traction in various
aspects of daily life. Consequently, conducting salient object detection (SOD)
in RGB-D videos presents a highly promising and evolving avenue. Despite the
potential of this area, SOD in RGB-D videos remains somewhat under-explored,
with RGB-D SOD and video SOD (VSOD) traditionally studied in isolation. To
explore this emerging field, this paper makes two primary contributions: the
dataset and the model. On one front, we construct the RDVS dataset, a new RGB-D
VSOD dataset with realistic depth and characterized by its diversity of scenes
and rigorous frame-by-frame annotations. We validate the dataset through
comprehensive attribute and object-oriented analyses, and provide training and
testing splits. Moreover, we introduce DCTNet+, a three-stream network tailored
for RGB-D VSOD, with an emphasis on RGB modality and treats depth and optical
flow as auxiliary modalities. In pursuit of effective feature enhancement,
refinement, and fusion for precise final prediction, we propose two modules:
the multi-modal attention module (MAM) and the refinement fusion module (RFM).
To enhance interaction and fusion within RFM, we design a universal interaction
module (UIM) and then integrate holistic multi-modal attentive paths (HMAPs)
for refining multi-modal low-level features before reaching RFMs. Comprehensive
experiments, conducted on pseudo RGB-D video datasets alongside our RDVS,
highlight the superiority of DCTNet+ over 17 VSOD models and 14 RGB-D SOD
models. Ablation experiments were performed on both pseudo and realistic RGB-D
video datasets to demonstrate the advantages of individual modules as well as
the necessity of introducing realistic depth. Our code together with RDVS
dataset will be available at https://github.com/kerenfu/RDVS/
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