1,283 research outputs found
Analyzing covariate clustering effects in healthcare cost subgroups: insights and applications for prediction
Healthcare cost prediction is a challenging task due to the
high-dimensionality and high correlation among covariates. Additionally, the
skewed, heavy-tailed, and often multi-modal nature of cost data can complicate
matters further due to unobserved heterogeneity. In this study, we propose a
novel framework for finite mixture regression models that incorporates
covariate clustering methods to better account for the effects of clustered
covariates on subgroups of the outcome, which enables a more accurate
characterization of the complex distribution of the data. The proposed
framework can be formulated as a convex optimization problem with an additional
penalty term based on the prior similarity of the covariates. To efficiently
solve this optimization problem, a specialized EM-ADMM algorithm is proposed
that integrates the alternating direction multiplicative method (ADMM) into the
iterative process of the expectation-maximizing (EM) algorithm. The convergence
of the algorithm and the efficiency of the covariate clustering method are
verified using simulation data, and the superiority of the approach over
traditional regression techniques is demonstrated using two real Chinese
medical expenditure datasets. Our empirical results provide valuable insights
into the complex network graph of the covariates and can inform business
practices, such as the design and pricing of medical insurance products.Comment: 36 pages; 7 figure
Quantifying chemical short-range order in metallic alloys
Metallic alloys often form phases - known as solid solutions - in which
chemical elements are spread out on the same crystal lattice in an almost
random manner. The tendency of certain chemical motifs to be more common than
others is known as chemical short-range order (SRO) and it has received
substantial consideration in alloys with multiple chemical elements present in
large concentrations due to their extreme configurational complexity (e.g.,
high-entropy alloys). Short-range order renders solid solutions "slightly less
random than completely random", which is a physically intuitive picture, but
not easily quantifiable due to the sheer number of possible chemical motifs and
their subtle spatial distribution on the lattice. Here we present a multiscale
method to predict and quantify the SRO state of an alloy with atomic
resolution, incorporating machine learning techniques to bridge the gap between
electronic-structure calculations and the characteristic length scale of SRO.
The result is an approach capable of predicting SRO length scale in agreement
with experimental measurements while comprehensively correlating SRO with
fundamental quantities such as local lattice distortions. This work advances
the quantitative understanding of solid-solution phases, paving the way for SRO
rigorous incorporation into predictive mechanical and thermodynamic models.Comment: 8 pages, 4 figure
A Fine-Grained Image Description Generation Method Based on Joint Objectives
The goal of fine-grained image description generation techniques is to learn
detailed information from images and simulate human-like descriptions that
provide coherent and comprehensive textual details about the image content.
Currently, most of these methods face two main challenges: description
repetition and omission. Moreover, the existing evaluation metrics cannot
clearly reflect the performance of models on these two issues. To address these
challenges, we propose an innovative Fine-grained Image Description Generation
model based on Joint Objectives. Furthermore, we introduce new object-based
evaluation metrics to more intuitively assess the model's performance in
handling description repetition and omission. This novel approach combines
visual features at both the image level and object level to maximize their
advantages and incorporates an object penalty mechanism to reduce description
repetition. Experimental results demonstrate that our proposed method
significantly improves the CIDEr evaluation metric, indicating its excellent
performance in addressing description repetition and omission issues
Stress Hyperglycemia: A Problem that Cannot be Ignored
Stress hyperglycemia is a strong neuroendocrine reaction in thehypothalamic pituitary adrenal cortex under severe infection, trauma, burns,hemorrhage, surgery and other harmful stimulated, resulting in increasedsecretion of counter-regulatory hormones. These hormones promotedthe production of sugar and cause glucose metabolism disorders withcytokines and insulin resistance. In this condition, the production of sugarexceeds the utilization of sugar by the tissues, which eventually leads to anincrease in blood glucose levels in plasma. In the intensive care unit, stresshyperglycemia is very common and can occur in patients with or withoutdiabetes. The incidence is as high as 96%, and it is an independent factorin the death of critically ill patients. Hyperglycemia not only prolongsthe hospitalization time, mechanical ventilation time and increased theincidence of serious infections in critically ill patients, but can also leadto the occurrence of type 2 diabetes. Therefore, it is very important tolearn the pathological mechanism of stress hyperglycemia, the harm ofhyperglycemia and blood sugar management
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