3,571 research outputs found
Bayesian Active Learning With Abstention Feedbacks
We study pool-based active learning with abstention feedbacks where a labeler
can abstain from labeling a queried example with some unknown abstention rate.
This is an important problem with many useful applications. We take a Bayesian
approach to the problem and develop two new greedy algorithms that learn both
the classification problem and the unknown abstention rate at the same time.
These are achieved by simply incorporating the estimated average abstention
rate into the greedy criteria. We prove that both algorithms have
near-optimality guarantees: they respectively achieve a
constant factor approximation of the optimal expected or worst-case value of a
useful utility function. Our experiments show the algorithms perform well in
various practical scenarios.Comment: Poster presented at 2019 ICML Workshop on Human in the Loop Learning
2019 (non-archival). arXiv admin note: substantial text overlap with
arXiv:1705.0848
Hogwild! over Distributed Local Data Sets with Linearly Increasing Mini-Batch Sizes
Hogwild! implements asynchronous Stochastic Gradient Descent (SGD) where
multiple threads in parallel access a common repository containing training
data, perform SGD iterations and update shared state that represents a jointly
learned (global) model. We consider big data analysis where training data is
distributed among local data sets in a heterogeneous way -- and we wish to move
SGD computations to local compute nodes where local data resides. The results
of these local SGD computations are aggregated by a central "aggregator" which
mimics Hogwild!. We show how local compute nodes can start choosing small
mini-batch sizes which increase to larger ones in order to reduce communication
cost (round interaction with the aggregator). We improve state-of-the-art
literature and show ) communication rounds for heterogeneous data
for strongly convex problems, where is the total number of gradient
computations across all local compute nodes. For our scheme, we prove a
\textit{tight} and novel non-trivial convergence analysis for strongly convex
problems for {\em heterogeneous} data which does not use the bounded gradient
assumption as seen in many existing publications. The tightness is a
consequence of our proofs for lower and upper bounds of the convergence rate,
which show a constant factor difference. We show experimental results for plain
convex and non-convex problems for biased (i.e., heterogeneous) and unbiased
local data sets.Comment: arXiv admin note: substantial text overlap with arXiv:2007.09208
AISTATS 202
Prevalence and Determinants of Medication Adherence among Patients with HIV/AIDS in Southern Vietnam
This study was conducted to determine the prevalence and determinants of medication adherence among patients with HIV/AIDS in southern Vietnam. METHODS: A cross-sectional study was conducted in a hospital in southern Vietnam from June to December 2019 on patients who began antiretroviral therapy (ART) for at least 6 months. Using a designed questionnaire, patients were considered adherent if they took correct medicines with right doses, on time and properly with food and beverage and had follow-up visits as scheduled. Multivariable logistic regression was used to identify determinants of adherence. KEY FINDINGS: A total of 350 patients (from 861 medical records) were eligible for the study. The majority of patients were male (62.9%), and the dominant age group (≥35 years old) accounted for 53.7% of patients. Sexual intercourse was the primary route of transmission of HIV (95.1%). The proportions of participants who took the correct medicine and at a proper dose were 98.3% and 86.3%, respectively. In total, 94.9% of participants took medicine appropriately in combination with food and beverage, and 75.7% of participants were strictly adherent to ART. The factors marital status (odds ratio (OR) = 2.54; 95%CI = 1.51-4.28), being away from home (OR = 1.7; 95%CI = 1.03-2.78), substance abuse (OR = 2.7; 95%CI = 1.44-5.05), general knowledge about ART (OR = 2.75; 95%CI = 1.67-4.53), stopping medication after improvement (OR = 4.16; 95%CI = 2.29-7.56) and self-assessment of therapy adherence (OR = 9.83; 95%CI = 5.44-17.77) were significantly associated with patients' adherence. CONCLUSIONS: Three-quarters of patients were adherent to ART. Researchers should consider these determinants of adherence in developing interventions in further studies
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