610 research outputs found
Process-Oriented Stream Classification Pipeline:A Literature Review
Featured Application: Nowadays, many applications and disciplines work on the basis of stream data. Common examples are the IoT sector (e.g., sensor data analysis), or video, image, and text analysis applications (e.g., in social media analytics or astronomy). With our work, we gather different approaches and terminology, and give a broad overview over the topic. Our main target groups are practitioners and newcomers to the field of data stream classification. Due to the rise of continuous data-generating applications, analyzing data streams has gained increasing attention over the past decades. A core research area in stream data is stream classification, which categorizes or detects data points within an evolving stream of observations. Areas of stream classification are diverse—ranging, e.g., from monitoring sensor data to analyzing a wide range of (social) media applications. Research in stream classification is related to developing methods that adapt to the changing and potentially volatile data stream. It focuses on individual aspects of the stream classification pipeline, e.g., designing suitable algorithm architectures, an efficient train and test procedure, or detecting so-called concept drifts. As a result of the many different research questions and strands, the field is challenging to grasp, especially for beginners. This survey explores, summarizes, and categorizes work within the domain of stream classification and identifies core research threads over the past few years. It is structured based on the stream classification process to facilitate coordination within this complex topic, including common application scenarios and benchmarking data sets. Thus, both newcomers to the field and experts who want to widen their scope can gain (additional) insight into this research area and find starting points and pointers to more in-depth literature on specific issues and research directions in the field.</p
Computational intelligence contributions to readmisision risk prediction in Healthcare systems
136 p.The Thesis tackles the problem of readmission risk prediction in healthcare systems from a machine learning and computational intelligence point of view. Readmission has been recognized as an indicator of healthcare quality with primary economic importance. We examine two specific instances of the problem, the emergency department (ED) admission and heart failure (HF) patient care using anonymized datasets from three institutions to carry real-life computational experiments validating the proposed approaches. The main difficulties posed by this kind of datasets is their high class imbalance ratio, and the lack of informative value of the recorded variables. This thesis reports the results of innovative class balancing approaches and new classification architectures
A Modulation Layer to Increase Neural Network Robustness Against Data Quality Issues
Data quality is a common problem in machine learning, especially in
high-stakes settings such as healthcare. Missing data affects accuracy,
calibration, and feature attribution in complex patterns. Developers often
train models on carefully curated datasets to minimize missing data bias;
however, this reduces the usability of such models in production environments,
such as real-time healthcare records. Making machine learning models robust to
missing data is therefore crucial for practical application. While some
classifiers naturally handle missing data, others, such as deep neural
networks, are not designed for unknown values. We propose a novel neural
network modification to mitigate the impacts of missing data. The approach is
inspired by neuromodulation that is performed by biological neural networks.
Our proposal replaces the fixed weights of a fully-connected layer with a
function of an additional input (reliability score) at each input, mimicking
the ability of cortex to up- and down-weight inputs based on the presence of
other data. The modulation function is jointly learned with the main task using
a multi-layer perceptron. We tested our modulating fully connected layer on
multiple classification, regression, and imputation problems, and it either
improved performance or generated comparable performance to conventional neural
network architectures concatenating reliability to the inputs. Models with
modulating layers were more robust against degradation of data quality by
introducing additional missingness at evaluation time. These results suggest
that explicitly accounting for reduced information quality with a modulating
fully connected layer can enable the deployment of artificial intelligence
systems in real-time settings
Recent Trends in Computational Intelligence
Traditional models struggle to cope with complexity, noise, and the existence of a changing environment, while Computational Intelligence (CI) offers solutions to complicated problems as well as reverse problems. The main feature of CI is adaptability, spanning the fields of machine learning and computational neuroscience. CI also comprises biologically-inspired technologies such as the intellect of swarm as part of evolutionary computation and encompassing wider areas such as image processing, data collection, and natural language processing. This book aims to discuss the usage of CI for optimal solving of various applications proving its wide reach and relevance. Bounding of optimization methods and data mining strategies make a strong and reliable prediction tool for handling real-life applications
Performance Analysis of UNet and Variants for Medical Image Segmentation
Medical imaging plays a crucial role in modern healthcare by providing
non-invasive visualisation of internal structures and abnormalities, enabling
early disease detection, accurate diagnosis, and treatment planning. This study
aims to explore the application of deep learning models, particularly focusing
on the UNet architecture and its variants, in medical image segmentation. We
seek to evaluate the performance of these models across various challenging
medical image segmentation tasks, addressing issues such as image
normalization, resizing, architecture choices, loss function design, and
hyperparameter tuning. The findings reveal that the standard UNet, when
extended with a deep network layer, is a proficient medical image segmentation
model, while the Res-UNet and Attention Res-UNet architectures demonstrate
smoother convergence and superior performance, particularly when handling fine
image details. The study also addresses the challenge of high class imbalance
through careful preprocessing and loss function definitions. We anticipate that
the results of this study will provide useful insights for researchers seeking
to apply these models to new medical imaging problems and offer guidance and
best practices for their implementation
Granular Support Vector Machines Based on Granular Computing, Soft Computing and Statistical Learning
With emergence of biomedical informatics, Web intelligence, and E-business, new challenges are coming for knowledge discovery and data mining modeling problems. In this dissertation work, a framework named Granular Support Vector Machines (GSVM) is proposed to systematically and formally combine statistical learning theory, granular computing theory and soft computing theory to address challenging predictive data modeling problems effectively and/or efficiently, with specific focus on binary classification problems. In general, GSVM works in 3 steps. Step 1 is granulation to build a sequence of information granules from the original dataset or from the original feature space. Step 2 is modeling Support Vector Machines (SVM) in some of these information granules when necessary. Finally, step 3 is aggregation to consolidate information in these granules at suitable abstract level. A good granulation method to find suitable granules is crucial for modeling a good GSVM. Under this framework, many different granulation algorithms including the GSVM-CMW (cumulative margin width) algorithm, the GSVM-AR (association rule mining) algorithm, a family of GSVM-RFE (recursive feature elimination) algorithms, the GSVM-DC (data cleaning) algorithm and the GSVM-RU (repetitive undersampling) algorithm are designed for binary classification problems with different characteristics. The empirical studies in biomedical domain and many other application domains demonstrate that the framework is promising. As a preliminary step, this dissertation work will be extended in the future to build a Granular Computing based Predictive Data Modeling framework (GrC-PDM) with which we can create hybrid adaptive intelligent data mining systems for high quality prediction
Predictive Modelling Approach to Data-Driven Computational Preventive Medicine
This thesis contributes novel predictive modelling approaches to data-driven computational preventive medicine and offers an alternative framework to statistical analysis in preventive medicine research. In the early parts of this research, this thesis presents research by proposing a synergy of machine learning methods for detecting patterns and developing inexpensive predictive models from healthcare data to classify the potential occurrence of adverse health events. In particular, the data-driven methodology is founded upon a heuristic-systematic assessment of several machine-learning methods, data preprocessing techniques, models’ training estimation and optimisation, and performance evaluation, yielding a novel computational data-driven framework, Octopus.
Midway through this research, this thesis advances research in preventive medicine and data mining by proposing several new extensions in data preparation and preprocessing. It offers new recommendations for data quality assessment checks, a novel multimethod imputation (MMI) process for missing data mitigation, a novel imbalanced resampling approach, and minority pattern reconstruction (MPR) led by information theory. This thesis also extends the area of model performance evaluation with a novel classification performance ranking metric called XDistance.
In particular, the experimental results show that building predictive models with the methods guided by our new framework (Octopus) yields domain experts' approval of the new reliable models’ performance. Also, performing the data quality checks and applying the MMI process led healthcare practitioners to outweigh predictive reliability over interpretability. The application of MPR and its hybrid resampling strategies led to better performances in line with experts' success criteria than the traditional imbalanced data resampling techniques. Finally, the use of the XDistance performance ranking metric was found to be more effective in ranking several classifiers' performances while offering an indication of class bias, unlike existing performance metrics
The overall contributions of this thesis can be summarised as follow. First, several data mining techniques were thoroughly assessed to formulate the new Octopus framework to produce new reliable classifiers. In addition, we offer a further understanding of the impact of newly engineered features, the physical activity index (PAI) and biological effective dose (BED). Second, the newly developed methods within the new framework. Finally, the newly accepted developed predictive models help detect adverse health events, namely, visceral fat-associated diseases and advanced breast cancer radiotherapy toxicity side effects. These contributions could be used to guide future theories, experiments and healthcare interventions in preventive medicine and data mining
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