Wyniki wyszukiwania - BazTech

1

Evaluation of lexicon- and syntax-based negation detection algorithms using clinical text data

Manimaran J., Velmurugan T.

Bio-Algorithms and Med-Systems

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2017

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Vol. 13, no. 4

201--213

EN

Background: Clinical Text Analysis and Knowledge Extraction System (cTAKES) is an open-source natural language processing (NLP) system. In recent development modules of cTAKES, a negation detection (ND) algorithm is used to improve annotation capabilities and simplify automatic identification of negative context in large clinical documents. In this research, the two types of ND algorithms used are lexicon and syntax, which are analyzed using a database made openly available by the National Center for Biomedical Computing. The aim of this analysis is to find the pros and cons of these algorithms. Methods: Patient medical reports were collected from three institutions included the 2010 i2b2/VA Clinical NLP Challenge, which is the input data for this analysis. This database includes patient discharge summaries and progress notes. The patient data is fed into five ND algorithms: NegEx, ConText, pyConTextNLP, DEEPEN and Negation Resolution (NR). NegEx, ConText and pyCon- TextNLP are lexicon-based, whereas DEEPEN and NR are syntax-based. The results from these five ND algorithms are post-processed and compared with the annotated data. Finally, the performance of these ND algorithms is evaluated by computing standard measures including F-measure, kappa statistics and ROC, among others, as well as the execution time of each algorithm. Results: This research is tested through practical implementation based on the accuracy of each algorithm’s results and computational time to evaluate its performance in order to find a robust and reliable ND algorithm. Conclusions: The performance of the chosen ND algorithms is analyzed based on the results produced by this research approach. The time and accuracy of each algorithm are calculated and compared to suggest the best method.

2

Advances in DGA-based diagnosis of power transformers - selected techniques

Szczepaniak P. S.

Problemy Eksploatacji

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2011

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nr 2

189-199

EN

To a large extent, the chromatographic data obtained by measurements on power transformers reflect the state of a power transformer and allow the assessment of possible faults. The distribution of real learning data is not even approximately uniform and makes the partitioning of decision space difficult. The purpose of this paper is to present the results of the application of an EC-based classifier and a number of novel methods.

PL

Jak wiadomo, wyniki analizy chromatograficznej gazów rozpuszczonych w oleju transformatorowym (Dissofoed Gas Analysis - DGA) mogą być użyte do diagnostyki transformatorów. Zwykle rozmieszczenie tych danych (ściśle ilorazów koncentracji wybranych gazów) w przestrzeni jest bardzo nierównomierne, a ponadto jednoznaczny podział tej przestrzeni na obszary decyzyjne o rozsądnej wielkości i liczbie jest bardzo trudny. Celem pracy jest dokonanie przeglądu zastosowań nowych metod, wśród nich tych mających korzenie w obliczeniach inteligentnych i odniesienie się do wyników uzyskiwanych za pomocą standardu EC (International Electrotechnical Commission).

3

Heart failure ontology

Jovic A., Gamberger D., Krstacic G.

Bio-Algorithms and Med-Systems

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2011

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Vol. 7, no. 2

101--110

EN

Ontology represents explicit specification of knowledge in a specific domain of interest in the form of concepts and relations among them. This paper presents a medical ontology describing the domain of heart failure (HF). Construction of ontology for a domain like HF is recognized as an important step in systematization of existing medical knowledge. The main virtue of ontology is that the represented knowledge is both computer and human-readable. The current development of the HF ontology is one of the main results of the EU Heartfaid project. The ontology has been implemented using Ontology Web Language and Protégé editing tool. It consists of roughly 200 classes, 100 relations and 2000 instances. The ontology is a precise, voluminous, portable, and upgradable representation of the HF domain. It is also a useful framework for building knowledge based systems in the HF domain, as well as for unambiguous communication between professionals. In the process of developing the HF ontology there have been significant technical and medical dilemmas. The current result should not be treated as the ultimate solution but as a starting point that will stimulate further research and development activities that can be very relevant for both intelligent computer systems and precise communication of medical knowledge.

4

Multivariate statistical interpretation of laboratory clinical data

Simeonova P., Simeonov V.

Chemia i Inżynieria Ekologiczna

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2007

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Vol. 14, nr 2

159-170

EN

Laboratory aids are extensively used in the diagnosis of diseases, in preventive medicine, and as management tools. Reference values of clinical healthy people serve as a guide to the clinician in evaluating parameters. Biochemical values obtained abroad may not be fully applicable to local conditions because they are influenced by race and environmental and management differences. Some variations also exist in results between laboratories using different reagents, methods, and instruments. Sometimes, laboratory findings about people are compared with reference values of other countries, which may not be a valid comparison. To our knowledge, references on biochemical serum of the healthy individuals do not yet exist. For the reasons mentioned, the purpose of this study was to determine reference serum biochemical values for the healthy population to form a basis for clinical interpretation. Further, the laboratory test results were subject to intelligent data analysis, which allows a-specific classification, modeling and interpretation. Multivariate statistical methods like cluster analysis and principal components analysis were applied in order to reveal the hidden data structure and to offer some new information on the relation between the parameters studied like separation with respect to sex and age.

PL

Wyniki analiz laboratoryjnych są szeroko wykorzystywana w diagnostyce chorób, medycynie prewencyjnej i jako narzędzia zarządzania. Wartości odniesienia parametrów charakteryzujących ludzi klinicznie zdrowych służą lekarzom jako odnośniki do oceny stanu zdrowia pacjenta. Wartości parametrów biochemicznych uzyskane zagranicą mogą nie być dobrym odnośnikiem w warunkach lokalnych ponieważ wpływają na nie rasa, różnice środowiskowe i sposób prowadzenia badań. Różnice wyników analiz pojawiają się takie pomiędzy laboratoriami, co jest wynikiem stosowania odmiennych odczynników, metod i aparatury. Celem naszych prac było określenie wartości odniesienia parametrów charakteryzujących surowicę krwi ludzi zdrowych, które tworzą podstawę klinicznej interpretacji tych samych parametrów surowicy ludzi chorych. Otrzymane wyniki badań były poddane analizom statystycznym, dzięki którym dokonano ich klasyfikacji, modelowania i interpretacji. Za pomocą analizy skupień i analizy składowych głównych ujawniono ukrytą strukturę danych oraz otrzymano nowe informacje o wpływie wieku i płci badanych osób na wartości parametrów surowicy.

5

Flow Graphs and Intelligent Data Analysis

Pawlak Z.

Fundamenta Informaticae

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2005

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Vol. 64, nr 1-4

369-377

EN

This paper concerns a new approach to intelligent data analysis based on information flow distribution study in a flow graph. Branches of a flow graph are interpreted as decision rules, whereas a flow graph is supposed to describe a decision algorithm. We propose to model decision processes as flow graphs and analyze decisions in terms of flow spreading in a graph.