11 research outputs found
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Automatic facial expression analysis
Humans spend a large amount of their time interacting with computers of one type or another. However, computers are emotionally blind and indifferent to the affective states of their users. Human-computer interaction which does not consider emotions, ignores a whole channel of available information.
Faces contain a large portion of our emotionally expressive behaviour. We use facial expressions to display our emotional states and to manage our interactions. Furthermore, we express and read emotions in faces effortlessly. However, automatic understanding of facial expressions is a very difficult task computationally, especially in the presence of highly variable pose, expression and illumination. My work furthers the field of automatic facial expression tracking by tackling these issues, bringing emotionally aware computing closer to reality.
Firstly, I present an in-depth analysis of the Constrained Local Model (CLM) for facial expression and head pose tracking. I propose a number of extensions that make location of facial features more accurate.
Secondly, I introduce a 3D Constrained Local Model (CLM-Z) which takes full advantage of depth information available from various range scanners. CLM-Z is robust to changes in illumination and shows better facial tracking performance.
Thirdly, I present the Constrained Local Neural Field (CLNF), a novel instance of CLM that deals with the issues of facial tracking in complex scenes. It achieves this through the use of a novel landmark detector and a novel CLM fitting algorithm. CLNF outperforms state-of-the-art models for facial tracking in presence of difficult illumination and varying pose.
Lastly, I demonstrate how tracked facial expressions can be used for emotion inference from videos. I also show how the tools developed for facial tracking can be applied to emotion inference in music
Analyzing Granger causality in climate data with time series classification methods
Attribution studies in climate science aim for scientifically ascertaining the influence of climatic variations on natural or anthropogenic factors. Many of those studies adopt the concept of Granger causality to infer statistical cause-effect relationships, while utilizing traditional autoregressive models. In this article, we investigate the potential of state-of-the-art time series classification techniques to enhance causal inference in climate science. We conduct a comparative experimental study of different types of algorithms on a large test suite that comprises a unique collection of datasets from the area of climate-vegetation dynamics. The results indicate that specialized time series classification methods are able to improve existing inference procedures. Substantial differences are observed among the methods that were tested
Separator fluid volume requirements in multi-infusion settings
INTRODUCTION. Intravenous (IV) therapy is a widely used method for the administration of medication in hospitals worldwide. ICU and surgical patients in particular often require multiple IV catheters due to incompatibility of certain drugs and the high complexity of medical therapy. This increases discomfort by painful invasive procedures, the risk of infections and costs of medication and disposable considerably. When different drugs are administered through the same lumen, it is common ICU practice to flush with a neutral fluid between the administration of two incompatible drugs in order to optimally use infusion lumens. An important constraint for delivering multiple incompatible drugs is the volume of separator fluid that is sufficient to safely separate them. OBJECTIVES. In this pilot study we investigated whether the choice of separator fluid, solvent, or administration rate affects the separator volume required in a typical ICU infusion setting. METHODS. A standard ICU IV line (2m, 2ml, 1mm internal diameter) was filled with methylene blue (40 mg/l) solution and flushed using an infusion pump with separator fluid. Independent variables were solvent for methylene blue (NaCl 0.9% vs. glucose 5%), separator fluid (NaCl 0.9% vs. glucose 5%), and administration rate (50, 100, or 200 ml/h). Samples were collected using a fraction collector until <2% of the original drug concentration remained and were analyzed using spectrophotometry. RESULTS. We did not find a significant effect of administration rate on separator fluid volume. However, NaCl/G5% (solvent/separator fluid) required significantly less separator fluid than NaCl/NaCl (3.6 ± 0.1 ml vs. 3.9 ± 0.1 ml, p <0.05). Also, G5%/G5% required significantly less separator fluid than NaCl/NaCl (3.6 ± 0.1 ml vs. 3.9 ± 0.1 ml, p <0.05). The significant decrease in required flushing volume might be due to differences in the viscosity of the solutions. However, mean differences were small and were most likely caused by human interactions with the fluid collection setup. The average required flushing volume is 3.7 ml. CONCLUSIONS. The choice of separator fluid, solvent or administration rate had no impact on the required flushing volume in the experiment. Future research should take IV line length, diameter, volume and also drug solution volumes into account in order to provide a full account of variables affecting the required separator fluid volume
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ESICM LIVES 2017 : 30th ESICM Annual Congress. September 23-27, 2017.
INTRODUCTION. Unplanned readmission to intensive care is highly
undesirable in that it contributes to increased variance in care,
disruption, difficulty in resource allocation and may increase length
of stay and mortality particularly if subject to delays. Unlike the ICU
admission from the ward, readmission prediction has received
relatively little attention, perhaps in part because at the point of ICU
discharge, full physiological information is systematically available to
the clinician and so it is expected that readmission should be largely
due to unpredictable factors. However it may be that there are
multidimensional trends that are difficult for the clinician to perceive
that may nevertheless be predictive of readmission.
OBJECTIVES. We investigated whether machine learning (ML)
techniques could be used to improve on the simple published SWIFT
score [1] for the prediction of unplanned readmission to ICU within
48 hours.
METHODS. We extracted systolic BP, pulse pressure, heart and
respiration rate, temperature, SpO2, bilirubin, creatinine, INR, lactate,
white cell count, platelet count, pH, FiO2, and total Glasgow Coma
Score from ICU stays of over 2000 adult patients from our hospital
electronic patient record system. We trained our own custom
multidimensional / time-sensitive algorithmic ML system to predict
failed discharges defined as either readmission or unexpected death
within 48 hours of discharge. We used 10-fold cross validation to assess performance. We also assessed the effect of augmenting our
system by transfer learning (TL) with 44,000 additional cases from
the MIMIC III database.
RESULTS. The SWIFT score performed relatively poorly with an
AUROC of around 0.6 which our ML system trained on local data was
also able to match. However when augmented with an additional
dataset by TL, the AUROC for the ML system improved statistically
and clinically significantly to over 0.7.
CONCLUSIONS. Machine learning is able to improve on predictors
based on simple multiple logistic regression. Thus there is likely to
be information in the trends and in combinations of variables. A
disadvantage with this technique is that ML approaches require large
amounts of data for training. However, ML approaches can be
improved by TL. Basing prediction models on locally derived data
augmented by TL is a potentially novel approach to generating tools
that customised to the institution yet can exploit the potential power
of ML algorithms.
REFERENCES
[1] Gajic O, Malinchoc M, Comfere TB, et al. The Stability and
Workload Index for Transfer score predicts unplanned intensive care
unit patient readmission: initial development and validation. Crit Care
Med. 2008;36(3):676–82.
Grant Acknowledgement
This work was internally funded
Socio-Cognitive and Affective Computing
Social cognition focuses on how people process, store, and apply information about other people and social situations. It focuses on the role that cognitive processes play in social interactions. On the other hand, the term cognitive computing is generally used to refer to new hardware and/or software that mimics the functioning of the human brain and helps to improve human decision-making. In this sense, it is a type of computing with the goal of discovering more accurate models of how the human brain/mind senses, reasons, and responds to stimuli. Socio-Cognitive Computing should be understood as a set of theoretical interdisciplinary frameworks, methodologies, methods and hardware/software tools to model how the human brain mediates social interactions. In addition, Affective Computing is the study and development of systems and devices that can recognize, interpret, process, and simulate human affects, a fundamental aspect of socio-cognitive neuroscience. It is an interdisciplinary field spanning computer science, electrical engineering, psychology, and cognitive science. Physiological Computing is a category of technology in which electrophysiological data recorded directly from human activity are used to interface with a computing device. This technology becomes even more relevant when computing can be integrated pervasively in everyday life environments. Thus, Socio-Cognitive and Affective Computing systems should be able to adapt their behavior according to the Physiological Computing paradigm. This book integrates proposals from researchers who use signals from the brain and/or body to infer people's intentions and psychological state in smart computing systems. The design of this kind of systems combines knowledge and methods of ubiquitous and pervasive computing, as well as physiological data measurement and processing, with those of socio-cognitive and affective computing
Proceedings of the European Conference on Agricultural Engineering AgEng2021
This proceedings book results from the AgEng2021 Agricultural Engineering Conference under auspices of the European Society of Agricultural Engineers, held in an online format based on the University of Évora,
Portugal, from 4 to 8 July 2021.
This book contains the full papers of a selection of abstracts that were the base for the oral presentations and posters presented at the conference.
Presentations were distributed in eleven thematic areas: Artificial Intelligence, data processing and
management; Automation, robotics and sensor technology; Circular Economy; Education and Rural development; Energy and bioenergy; Integrated and sustainable Farming systems; New application
technologies and mechanisation; Post-harvest technologies; Smart farming / Precision agriculture; Soil, land and water engineering; Sustainable production in Farm buildings
MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications
Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described