507 research outputs found
Signature of the +jet and dijet production mediated by an excited quark with QCD next-to-leading order accuracy at the LHC
We present a detailed study of the production and decay of the excited quark
at the QCD next-to-leading order (NLO) level at the Large Hadron Collider,
using the narrow width approximation and helicity amplitudes method. We find
that the QCD NLO corrections can tighten the constraints on the model
parameters and reduce the scale dependencies of the total cross sections. We
discuss the signals of the excited quark production with decay mode
and , and present several
important kinematic distributions. Moreover, we give the upper limits of the
excited quark excluded mass range and the allowed parameter space for the
coupling constants and the excited quark mass.Comment: 20 pages, 13 figures; version published in PR
Generalized Delayed Feedback Model with Post-Click Information in Recommender Systems
Predicting conversion rate (e.g., the probability that a user will purchase
an item) is a fundamental problem in machine learning based recommender
systems. However, accurate conversion labels are revealed after a long delay,
which harms the timeliness of recommender systems. Previous literature
concentrates on utilizing early conversions to mitigate such a delayed feedback
problem. In this paper, we show that post-click user behaviors are also
informative to conversion rate prediction and can be used to improve
timeliness. We propose a generalized delayed feedback model (GDFM) that unifies
both post-click behaviors and early conversions as stochastic post-click
information, which could be utilized to train GDFM in a streaming manner
efficiently. Based on GDFM, we further establish a novel perspective that the
performance gap introduced by delayed feedback can be attributed to a temporal
gap and a sampling gap. Inspired by our analysis, we propose to measure the
quality of post-click information with a combination of temporal distance and
sample complexity. The training objective is re-weighted accordingly to
highlight informative and timely signals. We validate our analysis on public
datasets, and experimental performance confirms the effectiveness of our
method.Comment: NeurIPS'2
Government Regulation of Online Game Addiction
While the Internet has changed the world with online knowledge, communication, and collaboration, it has also introduced online addiction. Online game addiction can be severe with tragic outcomes. Most governments and organizations are yet to recognize the severity of online game addiction and the need for intervention. We briefly review the literature on online game addiction. We also summarize the limited attempts of governments to develop regulations aimed at preventing online game addiction. Special attention is paid to China and its efforts to reduce the number of hours that young people can play online. We present evidence suggesting that online game addiction is an issue that should be considered by governments everywhere and that information systems researchers can play an important role in analyzing the impacts of government regulation of online addiction and shaping regulation improvements
Transverse momentum resummation for color sextet and antitriplet scalar production at the LHC
We study the factorization and resummation of the transverse momentum
spectrum of the color sextet and antitriplet scalars produced at the LHC based
on soft-collinear effective theory. Compared to Z boson and Higgs production, a
soft function is required to account for the soft gluon emission from the
final-state colored scalar. The soft function is calculated at the
next-to-leading order, and the resummation is performed at the approximate
next-to-next-to-leading logarithmic accuracy. The non-perturbative effects and
PDF uncertainties are also discussed.Comment: 20 pages, 7 figure
Threshold resummation for the production of a color sextet (antitriplet) scalar at the LHC
We investigate threshold resummation effects in the production of a color
sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order
at the LHC in the frame of soft-collinear effective theory. We show the total
cross section and the rapidity distribution with NLO+NNLL accuracy, and we
compare them with the NLO results. Besides, we use recent dijet data at the LHC
to give the constraints on the couplings between the colored scalars and
quarks.Comment: 21 pages,9 figures,3 tables; Version published in EPJ
Beyond Probability Partitions: Calibrating Neural Networks with Semantic Aware Grouping
Research has shown that deep networks tend to be overly optimistic about
their predictions, leading to an underestimation of prediction errors. Due to
the limited nature of data, existing studies have proposed various methods
based on model prediction probabilities to bin the data and evaluate
calibration error. We propose a more generalized definition of calibration
error called Partitioned Calibration Error (PCE), revealing that the key
difference among these calibration error metrics lies in how the data space is
partitioned. We put forth an intuitive proposition that an accurate model
should be calibrated across any partition, suggesting that the input space
partitioning can extend beyond just the partitioning of prediction
probabilities, and include partitions directly related to the input. Through
semantic-related partitioning functions, we demonstrate that the relationship
between model accuracy and calibration lies in the granularity of the
partitioning function. This highlights the importance of partitioning criteria
for training a calibrated and accurate model. To validate the aforementioned
analysis, we propose a method that involves jointly learning a semantic aware
grouping function based on deep model features and logits to partition the data
space into subsets. Subsequently, a separate calibration function is learned
for each subset. Experimental results demonstrate that our approach achieves
significant performance improvements across multiple datasets and network
architectures, thus highlighting the importance of the partitioning function
for calibration
The Capacity and Robustness Trade-off: Revisiting the Channel Independent Strategy for Multivariate Time Series Forecasting
Multivariate time series data comprises various channels of variables. The
multivariate forecasting models need to capture the relationship between the
channels to accurately predict future values. However, recently, there has been
an emergence of methods that employ the Channel Independent (CI) strategy.
These methods view multivariate time series data as separate univariate time
series and disregard the correlation between channels. Surprisingly, our
empirical results have shown that models trained with the CI strategy
outperform those trained with the Channel Dependent (CD) strategy, usually by a
significant margin. Nevertheless, the reasons behind this phenomenon have not
yet been thoroughly explored in the literature. This paper provides
comprehensive empirical and theoretical analyses of the characteristics of
multivariate time series datasets and the CI/CD strategy. Our results conclude
that the CD approach has higher capacity but often lacks robustness to
accurately predict distributionally drifted time series. In contrast, the CI
approach trades capacity for robust prediction. Practical measures inspired by
these analyses are proposed to address the capacity and robustness dilemma,
including a modified CD method called Predict Residuals with Regularization
(PRReg) that can surpass the CI strategy. We hope our findings can raise
awareness among researchers about the characteristics of multivariate time
series and inspire the construction of better forecasting models.Comment: under revie
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