3,174 research outputs found
Hierarchical relational models for document networks
We develop the relational topic model (RTM), a hierarchical model of both
network structure and node attributes. We focus on document networks, where the
attributes of each document are its words, that is, discrete observations taken
from a fixed vocabulary. For each pair of documents, the RTM models their link
as a binary random variable that is conditioned on their contents. The model
can be used to summarize a network of documents, predict links between them,
and predict words within them. We derive efficient inference and estimation
algorithms based on variational methods that take advantage of sparsity and
scale with the number of links. We evaluate the predictive performance of the
RTM for large networks of scientific abstracts, web documents, and
geographically tagged news.Comment: Published in at http://dx.doi.org/10.1214/09-AOAS309 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
ExClaim: Explainable Neural Claim Verification Using Rationalization
With the advent of deep learning, text generation language models have
improved dramatically, with text at a similar level as human-written text. This
can lead to rampant misinformation because content can now be created cheaply
and distributed quickly. Automated claim verification methods exist to validate
claims, but they lack foundational data and often use mainstream news as
evidence sources that are strongly biased towards a specific agenda. Current
claim verification methods use deep neural network models and complex
algorithms for a high classification accuracy but it is at the expense of model
explainability. The models are black-boxes and their decision-making process
and the steps it took to arrive at a final prediction are obfuscated from the
user. We introduce a novel claim verification approach, namely: ExClaim, that
attempts to provide an explainable claim verification system with foundational
evidence. Inspired by the legal system, ExClaim leverages rationalization to
provide a verdict for the claim and justifies the verdict through a natural
language explanation (rationale) to describe the model's decision-making
process. ExClaim treats the verdict classification task as a question-answer
problem and achieves a performance of 0.93 F1 score. It provides subtasks
explanations to also justify the intermediate outcomes. Statistical and
Explainable AI (XAI) evaluations are conducted to ensure valid and trustworthy
outcomes. Ensuring claim verification systems are assured, rational, and
explainable is an essential step toward improving Human-AI trust and the
accessibility of black-box systems.Comment: Published at 2022 IEEE 29th ST
Multilingual Topic Labelling of News Topics using Ontological Mapping
The large volume of news produced daily makes topic modelling useful for analysing topical trends. A topic is usually represented by a ranked list of words but this can be difficult and time-consuming for humans to interpret. Therefore, various methods have been proposed to generate labels that capture the semantic content of a topic. However, there has been no work so far on coming up with multilingual labels which can be useful for exploring multilingual news collections. We propose an ontological mapping method that maps topics to concepts in a language-agnostic news ontology. We test our method on Finnish and English topics and show that it performs on par with state-of-the-art label generation methods, is able to produce multilingual labels, and can be applied to topics from languages that have not been seen during training without any modifications.Peer reviewe
Sentiment Analysis Based on the BERT Model : Attitudes Towards Politicians Using Media Data
The latest analysis methods of sentiments borrowed from computational linguistics are relevant in the age of big data, which is difficult to process through traditional content analysis. These methods have made it possible to analyze information over a long period, which allows us to trace the dynamics of the relationship to a particular object over time and large-scale comparative studies of texts. The authors demonstrate the applicability of sentiment analysis based on transformer models to the study of the temporal model of attitudes towards well-known politicians (2001-2021) on the example of text analysis of multilingual online publications. To do this, the authors used the targeted-BERT method for automated directed analysis of sentiments, obtained quality indicators F1-score 0.799 and 0.741 for Ukrainian and Russian models, respectively. The authors tested the dependence of mediatization of politicians on the country's political hierarchy, confirmed hypotheses about the attitude to their power (more significant criticism of the Ukrainian media and gradual loyalty to the Russian media) and foreign politicians (dominance of negative tone in both media with a growing trend for Ukrainian media).Non peer reviewe
Relevant Emotion Ranking from Text Constraint with Emotion Relationships
Text might contain or invoke multiple emotions with varying intensities. As such, emotion detection, to predict multiple emotions associated with a given text, can be cast into a multi-label classification problem. We would like to go one step further so that a ranked list of relevant emotions are generated where top ranked emotions are more intensely associated with text compared to lower ranked emotions, whereas the rankings of irrelevant emotions are not important. A novel framework of relevant emotion ranking is proposed to tackle the problem. In the framework, the objective loss function is designed elaborately so that both emotion prediction and rankings of only relevant emotions can be achieved. Moreover, we observe that some emotions cooccur more often while other emotions rarely co-exist. Such information is incorporated into the framework as constraints to improve the accuracy of emotion detection. Experimental results on two real-world corpora show that the proposed framework can effectively deal with emotion detection and performs remarkably better than the state-of-the-art emotion detection approaches and multi-label learning methods
A proof-of-concept study on mortality prediction with machine learning algorithms using burn intensive care data
INTRODUCTION: Burn injuries are a common traumatic injury. Large burns have high mortality requiring intensive care and accurate mortality predictions. To assess if machine learning (ML) could improve predictions, ML algorithms were tested and compared with the original and revised Baux score. METHODS: Admission data and mortality outcomes were collected from patients at Uppsala University Hospital Burn Centre from 2002 to 2019. Prognostic variables were selected, ML algorithms trained and predictions assessed by analysis of the area under the receiver operating characteristic curve (AUC). Comparison was made with Baux scores using DeLong test. RESULTS: A total of 17 prognostic variables were selected from 92 patients. AUCs in leave-one-out cross-validation for a decision tree model, an extreme boosting model, a random forest model, a support-vector machine (SVM) model and a generalised linear regression model (GLM) were 0.83 (95% confidence interval [CI] = 0.72-0.94), 0.92 (95% CI = 0.84-1), 0.92 (95% CI = 0.84-1), 0.92 (95% CI = 0.84-1) and 0.84 (95% CI = 0.74-0.94), respectively. AUCs for the Baux score and revised Baux score were 0.85 (95% CI = 0.75-0.95) and 0.84 (95% CI = 0.74-0.94). No significant differences were observed when comparing ML algorithms with Baux score and revised Baux score. Secondary variable selection was made to analyse model performance. CONCLUSION: This proof-of-concept study showed initial credibility in using ML algorithms to predict mortality in burn patients. The sample size was small and future studies are needed with larger sample sizes, further variable selections and prospective testing of the algorithms. LAY SUMMARY: Burn injuries are one of the most common traumatic injuries especially in countries with limited prevention and healthcare resources. To treat a patient with large burns who has been admitted to an intensive care unit, it is often necessary to assess the risk of a fatal outcome. Physicians traditionally use simplified scores to calculate risks. One commonly used score, the Baux score, uses age of the patient and the size of the burn to predict the risk of death. Adding the factor of inhalation injury, the score is then called the revised Baux score. However, there are a number of additional causes that can influence the risk of fatal outcomes that Baux scores do not take into account. Machine learning is a method of data modelling where the system learns to predict outcomes based on previous cases and is a branch of artificial intelligence. In this study we evaluated several machine learning methods for outcome prediction in patients admitted for burn injury. We gathered data on 93 patients at admission to the intensive care unit and our experiments show that machine learning methods can reach an accuracy comparable with Baux scores in calculating the risk of fatal outcomes. This study represents a proof of principle and future studies on larger patient series are required to verify our results as well as to evaluate the methods on patients in real-life situations.Peer reviewe
The current state of biomarker research for Friedreich's ataxia: a report from the 2018 FARA biomarker meeting
The 2018 FARA Biomarker Meeting highlighted the current state of development of biomarkers for Friedreich's ataxia. A mass spectroscopy assay to sensitively measure mature frataxin (reduction of which is the root cause of disease) is being developed. Biomarkers to monitor neurological disease progression include imaging, electrophysiological measures and measures of nerve function, which may be measured either in serum and/or through imaging-based technologies. Potential pharmacodynamic biomarkers include metabolic and protein biomarkers and markers of nerve damage. Cardiac imaging and serum biomarkers may reflect cardiac disease progression. Considerable progress has been made in the development of biomarkers for various contexts of use, but further work is needed in terms of larger longitudinal multisite studies, and identification of novel biomarkers for additional use cases
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