Concept-based Classification Research Articles

Clinical Concept-Based Radiology Reports Classification Pipeline for Lung Carcinoma

Rising incidence and mortality of cancer have led to an incremental amount of research in the field. To learn from preexisting data, it has become important to capture maximum information related to disease type, stage, treatment, and outcomes. Medical imaging reports are rich in this kind of information but are only present as free text. The extraction of information from such unstructured text reports is labor-intensive. The use of Natural Language Processing (NLP) tools to extract information from radiology reports can make it less time-consuming as well as more effective. In this study, we have developed and compared different models for the classification of lung carcinoma reports using clinical concepts. This study was approved by the institutional ethics committee as a retrospective study with a waiver of informed consent. A clinical concept-based classification pipeline for lung carcinoma radiology reports was developed using rule-based as well as machine learning models and compared. The machine learning models used were XGBoost and two more deep learning model architectures with bidirectional long short-term neural networks. A corpus consisting of 1700 radiology reports including computed tomography (CT) and positron emission tomography/computed tomography (PET/CT) reports were used for development and testing. Five hundred one radiology reports from MIMIC-III Clinical Database version 1.4 was used for external validation. The pipeline achieved an overall F1 score of 0.94 on the internal set and 0.74 on external validation with the rule-based algorithm using expert input giving the best performance. Among the machine learning models, the Bi-LSTM_dropout model performed better than the ML model using XGBoost and the Bi-LSTM_simple model on internal set, whereas on external validation, the Bi-LSTM_simple model performed relatively better than other 2. This pipeline can be used for clinical concept-based classification of radiology reports related to lung carcinoma from a huge corpus and also for automated annotation of these reports.

Predicting software defect type using concept-based classification

Automatically predicting the defect type of a software defect from its description can significantly speed up and improve the software defect management process. A major challenge for the supervised learning based current approaches for this task is the need for labeled training data. Creating such data is an expensive and effort-intensive task requiring domain-specific expertise. In this paper, we propose to circumvent this problem by carrying out concept-based classification (CBC) of software defect reports with help of the Explicit Semantic Analysis (ESA) framework. We first create the concept-based representations of a software defect report and the defect types in the software defect classification scheme by projecting their textual descriptions into a concept-space spanned by the Wikipedia articles. Then, we compute the “semantic” similarity between these concept-based representations and assign the software defect type that has the highest similarity with the defect report. The proposed approach achieves accuracy comparable to the state-of-the-art semi-supervised and active learning approach for this task without requiring labeled training data. Additional advantages of the CBC approach are: (i) unlike the state-of-the-art, it does not need the source code used to fix a software defect, and (ii) it does not suffer from the class-imbalance problem faced by the supervised learning paradigm.

Modelling Concept Prototype Competencies using a Developmental Memory Model

AbstractThe use of concepts is fundamental to human-level cognition, but there remain a number of open questions as to the structures supporting this competence. Specifically, it has been shown that humans use concept prototypes, a flexible means of representing concepts such that it can be used both for categorisation and for similarity judgements. In the context of autonomous robotic agents, the processes by which such concept functionality could be acquired would be particularly useful, enabling flexible knowledge representation and application. This paper seeks to explore this issue of autonomous concept acquisition. By applying a set of structural and operational principles, that support a wide range of cognitive competencies, within a developmental framework, the intention is to explicitly embed the development of concepts into a wider framework of cognitive processing. Comparison with a benchmark concept modelling system shows that the proposed approach can account for a number of features, namely concept-based classification, and its extension to prototype-like functionality.

Concept-Based Semi-Automatic Classification of Drugs

The anatomical therapeutic chemical (ATC) classification system maintained by the World Health Organization provides a global standard for the classification of medical substances and serves as a source for drug repurposing research. Nevertheless, it lacks several drugs that are major players in the global drug market. In order to establish classifications for yet unclassified drugs, this paper presents a newly developed approach based on a combination of information extraction (IE) and machine learning (ML) techniques. Most of the information about drugs is published in the scientific articles. Therefore, an IE-based framework is employed to extract terms from free text that express drug's chemical, pharmacological, therapeutic, and systemic effects. The extracted terms are used as features within a ML framework to predict putative ATC class labels for unclassified drugs. The system was tested on a portion of ATC containing drugs with an indication on the cardiovascular system. The class prediction turned out to be successful with the best predictive accuracy of 89.47% validated by a 100-fold bootstrapping of the training set and an accuracy of 77.12% on an independent test set. The presented concept-based classification system outperformed state-of-the-art classification methods based on chemical structure properties.

Complexity of learning in concept lattices from positive and negative examples

A model of learning from positive and negative examples in concept lattices is considered. Lattice- and graph-theoretic interpretations of learning concept-based classification rules (called hypotheses) and classification in this model are given. The problems of counting all formal concepts, all hypotheses, and all minimal hypotheses are shown to be #P-complete. NP-completeness of some decision problems related to learning and classification in this setting is demonstrated and several conditions of tractability of these problems are considered. Some useful particular cases where these problems can be solved in polynomial time are indicated.