143 research outputs found
Segment Parameter Labelling in MCMC Mean-Shift Change Detection
This work addresses the problem of segmentation in time series data with
respect to a statistical parameter of interest in Bayesian models. It is common
to assume that the parameters are distinct within each segment. As such, many
Bayesian change point detection models do not exploit the segment parameter
patterns, which can improve performance. This work proposes a Bayesian
mean-shift change point detection algorithm that makes use of repetition in
segment parameters, by introducing segment class labels that utilise a
Dirichlet process prior. The performance of the proposed approach was assessed
on both synthetic and real world data, highlighting the enhanced performance
when using parameter labelling
Interpreting Differentiable Latent States for Healthcare Time-series Data
Machine learning enables extracting clinical insights from large temporal
datasets. The applications of such machine learning models include identifying
disease patterns and predicting patient outcomes. However, limited
interpretability poses challenges for deploying advanced machine learning in
digital healthcare. Understanding the meaning of latent states is crucial for
interpreting machine learning models, assuming they capture underlying
patterns. In this paper, we present a concise algorithm that allows for i)
interpreting latent states using highly related input features; ii)
interpreting predictions using subsets of input features via latent states; and
iii) interpreting changes in latent states over time. The proposed algorithm is
feasible for any model that is differentiable. We demonstrate that this
approach enables the identification of a daytime behavioral pattern for
predicting nocturnal behavior in a real-world healthcare dataset
A Deep Multi-View Learning Framework for City Event Extraction from Twitter Data Streams
Cities have been a thriving place for citizens over the centuries due to
their complex infrastructure. The emergence of the Cyber-Physical-Social
Systems (CPSS) and context-aware technologies boost a growing interest in
analysing, extracting and eventually understanding city events which
subsequently can be utilised to leverage the citizen observations of their
cities. In this paper, we investigate the feasibility of using Twitter textual
streams for extracting city events. We propose a hierarchical multi-view deep
learning approach to contextualise citizen observations of various city systems
and services. Our goal has been to build a flexible architecture that can learn
representations useful for tasks, thus avoiding excessive task-specific feature
engineering. We apply our approach on a real-world dataset consisting of event
reports and tweets of over four months from San Francisco Bay Area dataset and
additional datasets collected from London. The results of our evaluations show
that our proposed solution outperforms the existing models and can be used for
extracting city related events with an averaged accuracy of 81% over all
classes. To further evaluate the impact of our Twitter event extraction model,
we have used two sources of authorised reports through collecting road traffic
disruptions data from Transport for London API, and parsing the Time Out London
website for sociocultural events. The analysis showed that 49.5% of the Twitter
traffic comments are reported approximately five hours prior to the authorities
official records. Moreover, we discovered that amongst the scheduled
sociocultural event topics; tweets reporting transportation, cultural and
social events are 31.75% more likely to influence the distribution of the
Twitter comments than sport, weather and crime topics
Using Entropy Measures for Monitoring the Evolution of Activity Patterns
In this work, we apply information theory inspired methods to quantify changes in daily activity patterns. We use in-home movement monitoring data and show how they can help indicate the occurrence of healthcare-related events. Three different types of entropy measures namely Shannon's entropy, entropy rates for Markov chains, and entropy production rate have been utilised. The measures are evaluated on a large-scale in-home monitoring dataset that has been collected within our dementia care clinical study. The study uses Internet of Things (IoT) enabled solutions for continuous monitoring of in-home activity, sleep, and physiology to develop care and early intervention solutions to support people living with dementia (PLWD) in their own homes. Our main goal is to show the applicability of the entropy measures to time-series activity data analysis and to use the extracted measures as new engineered features that can be fed into inference and analysis models. The results of our experiments show that in most cases the combination of these measures can indicate the occurrence of healthcare-related events. We also find that different participants with the same events may have different measures based on one entropy measure. So using a combination of these measures in an inference model will be more effective than any of the single measures
Comparing machine learning clustering with latent class analysis on cancer symptoms' data
Symptom Cluster Research is a major topic in Cancer Symptom Science. In spite of the several statistical and clinical approaches in this domain, there is not a consensus on which method performs better. Identifying a generally accepted analytical method is important in order to be able to utilize and process all the available data. In this paper we report a secondary analysis on cancer symptom data, comparing the performance of five Machine Learning (ML) clustering algorithms in doing so. Based on how well they separate specific subsets of symptom measurements we select the best of them and proceed to compare its performance with the Latent Class Analysis (LCA) method. This analysis is a part of an ongoing study for identifying suitable Machine Learning algorithms to analyse and predict cancer symptoms in cancer treatment
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