52 research outputs found
Predicting the Evolution of Communities with Online Inductive Logic Programming
In the recent years research on dynamic social network has increased, which is also due to the availability of data sets from streaming media. Modeling a network\u27s dynamic behaviour can be performed at the level of communities, which represent their mesoscale structure. Communities arise as a result of user to user interaction. In the current work we aim to predict the evolution of communities, i.e. to predict their future form. While this problem has been studied in the past as a supervised learning problem with a variety of classifiers, the problem is that the "knowledge" of a classifier is opaque and consequently incomprehensible to a human. Thus we have employed first order logic, and in particular the event calculus to represent the communities and their evolution. We addressed the problem of predicting the evolution as an online Inductive Logic Programming problem (ILP), where the issue is to learn first order logical clauses that associate evolutionary events, and particular Growth, Shrinkage, Continuation and Dissolution to lower level events. The lower level events are features that represent the structural and temporal characteristics of communities. Experiments have been performed on a real life data set form the Mathematics StackExchange forum, with the OLED framework for ILP. In doing so we have produced clauses that model both short term and long term correlations
Tree-based Focused Web Crawling with Reinforcement Learning
A focused crawler aims at discovering as many web pages relevant to a target
topic as possible, while avoiding irrelevant ones. Reinforcement Learning (RL)
has been utilized to optimize focused crawling. In this paper, we propose TRES,
an RL-empowered framework for focused crawling. We model the crawling
environment as a Markov Decision Process, which the RL agent aims at solving by
determining a good crawling strategy. Starting from a few human provided
keywords and a small text corpus, that are expected to be relevant to the
target topic, TRES follows a keyword set expansion procedure, which guides
crawling, and trains a classifier that constitutes the reward function. To
avoid a computationally infeasible brute force method for selecting a best
action, we propose Tree-Frontier, a decision-tree-based algorithm that
adaptively discretizes the large state and action spaces and finds only a few
representative actions. Tree-Frontier allows the agent to be likely to select
near-optimal actions by being greedy over selecting the best representative
action. Experimentally, we show that TRES significantly outperforms
state-of-the-art methods in terms of harvest rate (ratio of relevant pages
crawled), while Tree-Frontier reduces by orders of magnitude the number of
actions needed to be evaluated at each timestep
LSHTC: A Benchmark for Large-Scale Text Classification
LSHTC is a series of challenges which aims to assess the performance of
classification systems in large-scale classification in a a large number of
classes (up to hundreds of thousands). This paper describes the dataset that
have been released along the LSHTC series. The paper details the construction
of the datsets and the design of the tracks as well as the evaluation measures
that we implemented and a quick overview of the results. All of these datasets
are available online and runs may still be submitted on the online server of
the challenges
Calibrating mini-mental state examination scores to predict misdiagnosed dementia patients
Mini-Mental State Examination (MMSE) is used as a diagnostic test for dementia to screen a patient’s cognitive assessment and disease severity. However, these examinations are often inaccurate and unreliable either due to human error or due to patients’ physical disability to correctly interpret the questions as well as motor deficit. Erroneous data may lead to a wrong assessment of a specific patient. Therefore, other clinical factors (e.g., gender and comorbidities) existing in electronic health records, can also play a significant role, while reporting her examination results. This work considers various clinical attributes of dementia patients to accurately determine their cognitive status in terms of the Mini-Mental State Examination (MMSE) Score. We employ machine learning models to calibrate MMSE score and classify the correctness of diagnosis among patients, in order to assist clinicians in a better understanding of the progression of cognitive impairment and subsequent treatment. For this purpose, we utilize a curated real-world ageing study data. A random forest prediction model is employed to estimate the Mini-Mental State Examination score, related to the diagnostic classification of patients.This model uses various clinical attributes to provide accurate MMSE predictions, succeeding in correcting an important percentage of cases that contain previously identified miscalculated scores in our dataset. Furthermore, we provide an effective classification mechanism for automatically identifying patient episodes with inaccurate MMSE values with high confidence. These tools can be combined to assist clinicians in automatically finding episodes within patient medical records where the MMSE score is probably miscalculated and estimating what the correct value should be. This provides valuable support in the decision making process for diagnosing potential dementia patients. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
A Data-Driven Approach for Analyzing Healthcare Services Extracted from Clinical Records
Cancer remains one of the major public health challenges worldwide. After cardiovascular diseases, cancer is one of the first causes of death and morbidity in Europe, with more than 4 million new cases and 1.9 million deaths per year. The suboptimal management of cancer patients during treatment and subsequent follows up are major obstacles in achieving better outcomes of the patients and especially regarding cost and quality of life In this paper, we present an initial data-driven approach to analyze the resources and services that are used more frequently by lung-cancer patients with the aim of identifying where the care process can be improved by paying a special attention on services before diagnosis to being able to identify possible lung-cancer patients before they are diagnosed and by reducing the length of stay in the hospital. Our approach has been built by analyzing the clinical notes of those oncological patients to extract this information and their relationships with other variables of the patient. Although the approach shown in this manuscript is very preliminary, it shows that quite interesting outcomes can be derived from further analysis. © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works
Blurred vision due to choroidal metastasis as the first manifestation of lung cancer: A case report
<p>Abstract</p> <p>Background</p> <p>Reduction in visual acuity combined with blurred vision is rarely the first sign of lung cancer and very few cases have been announced globally.</p> <p>Case presentation</p> <p>A case of a 46-year-old man who admitted with blurred vision is presented. His medical history, apart from a mild gastritis under treatment was negative. Ocular examination revealed a decrease in visual acuity due to a choroidal tumor. Further image body scans demonstrated a right lung lesion with dissemination to other organs. Diagnosis of a non-small cell lung cancer established after a VATS biopsy carried out.</p> <p>Conclusion</p> <p>Blurred vision due to choroidal metastasis as the primary symptom of lung cancer is very uncommon. A great index of suspicion is essential when a choroidal lesion appears.</p
Behaviour recognition using the event calculus
Abstract We present a system for recognising human behaviour given a symbolic representation of surveillance videos. The input of our system is a set of timestamped short-term behaviours, that is, behaviours taking place in a short period of time — walking, running, standing still, etc — detected on video frames. The output of our system is a set of recognised long-term behaviours — fighting, meeting, leaving an object, collapsing, walking, etc — which are pre-defined temporal combinations of short-term behaviours. The definition of a long-term behaviour, including the temporal constraints on the short-term behaviours that, if satisfied, lead to the recognition of the long-term behaviour, is expressed in the Event Calculus. We present experimental results concerning videos with several humans and objects, temporally overlapping and repetitive behaviours.
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