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Biomedical subjects

R Rada

Publications and source records attributed to R Rada.

16 recordsLinked to original sources
PubMed1994

An object-oriented approach to knowledge representation in a biomedical domain.

An object-oriented approach has been applied to the different stages involved in developing a knowledge base about insulin metabolism. At an early stage the separation of terminological and assertional knowledge was made. The terminological component was developed by medical experts and represented in CORE. An object-oriented knowledge acquisition process was applied to the assertional knowledge. A frame description is proposed which includes features like states and events, inheritance and collaboration. States and events are formalized with qualitative calculus. The terminological knowledge was very useful in the development of the assertional component. It assisted in understanding the problem domain, and in the implementation stage, it assisted in building good inheritance hierarchies.

Algorithms↗
PubMed1988

Mapping from GenBank to MEDLINE.

GenBank has been based largely on literature that provides nucleic acid sequences. To find additional literature that is relevant to a given sequence, a search of MEDLINE can prove helpful. This paper documents some of the similarities between GenBank and MEDLINE that facilitate retrieval of documents from MEDLINE. In particular, techniques and examples are presented which take GenBank information and lead to MEDLINE information that supplements the GenBank information.

Abstracting and Indexing↗
PubMed1987

A vocabulary for medical informatics.

The terminology in medical informatics is evolving rapidly. The organizers of MEDINFO and SCAMC have used different sets of keywords to index their documents. Recognizing the limitations of this approach, members of those organizations joined with the National Library of Medicine in the creation of a better terminology for medical informatics. A hierarchical structure was placed on the terms to produce a thesaurus typical of the sort often used in the indexing and retrieving of documents. The building of this thesaurus began with an automatic merging of the thesaurus used by the Association of Computing Machinery and the Information Sciences component of the "Medical Subject Headings." This product was pruned by eliminating terms not related to those in the MEDINFO keyword list or not in the medical informatics literature. Further refinement of the thesaurus resulted from extensive discussions among the authors of this paper. The first major application of this terminology has been to the indexing of the articles in "MEDINFO-86 Proceedings." Major components of this medical informatics thesaurus also have been incorporated into the "Medical Subject Headings." This paper describes the process of preparing the thesaurus and presents an evaluation of its coverage of the "MEDINFO-86 Proceedings."

Abstracting and Indexing↗
PubMed1987

Searching for patterns in the MeSH vocabulary.

NLM revises its MeSH vocabulary annually to reflect changes in biomedical literature and the health sciences community. This study tested two hypotheses about NLM's MeSH vocabulary. The first is that new terms are added to MeSH when their broader terms have an increased number of postings. One examination compared the number of postings for the broader terms of new and existing terms in the current MEDLINE file; the other compared them over time. No significant statistical difference was found in either case. A second hypothesis--that there is a relationship between the patterns of MEDLINE indexing and searching and the organization of the MeSH tree structure--was tested by comparing the distribution of searched terms in the MeSH trees with the distribution of all terms. It was found that certain trees are searched more often than could be predicted by the overall term distribution, while others are searched less frequently than expected. In summary, (1) new terms cannot be predicted by the increase in postings of existing terms, and (2) searchers' and indexers' use of the terms' tree structure does not correlate with the terms' distribution in the MeSH trees.

Abstracting and Indexing↗
PubMed1982

Evolutionary search: gradients and information.

To better understand evolution one might view evolution as a search algorithm proceeding through a search space. The search method implemented by reproduction with mutation and selection of the fit does not perform efficiently on many search spaces. Characteristics of the search space are critically important to the effectiveness of the search algorithm. The "gradients" of and the "information" in a search space are used in this paper to study performance of "evolutionary" search algorithms.

Animals↗
PubMed1981

Evolution and gradualness.

Evolutionary systems are commonly considered to have fundamental properties: (1) elements (or organisms) in the system reproduce with mutation and (2) only the fit elements survive. I propose that evolutionary systems have a third property - the property of gradualness. A system has gradualness, if, and only if, small changes in an element usually lead to small changes in that element's fitness. I have formalized a framework from which attempts to design evolutionary systems might proceed. Of particular importance are the criteria, based on the notion of perpetuation, which a system's behavior must satisfy in order to be considered evolutionary. By my standards, no computer programs have been designed that manifest meaningful evolutionary behavior.

Biological Evolution↗
PubMed1981

Searching and gradualness.

Consider the elements of the power set S as the alternatives in a search space. Each element of the set has a value and the goal of a search is to find an element with near-minimum value. If high-valued elements of cardinality i (recall that elements of S are themselves sets) are subsets of high-valued elements of cardinality i + 1, then the search space has a king of gradualness that should facilitate search. A search algorithm might generate a series, S' (1), . . . S' (k) of samples in S, where all the elements in S' (i) have cardinality i. I propose a class of search algorithms, where each algorithm A(j) generates S' (i + 1) by emphasizing the j lowest-valued elements in S' (i). I then define search space gradualness and search algorithm performance and formally relate gradualness and performance.

Biological Evolution↗
PubMedDate not supplied

Building a relational database for a physician document index.

We show how three existing medical knowledge bases: Medical Subject Headings (MeSH), Standardized Nomenclature of Medicine (SNOMED) and Current Medical Information and Technology (CMIT) are mapped into a relational data model and stored on an Apollo workstation and an Intelligent Database Machine. Since two of these knowledge bases have been used in the indexing of medical literature and patient records, they can be useful not only as direct views on the organization of medical concepts but also as tools for the retrieval of documents. In order that the concepts from one knowledge base can be connected to those of the other knowledge base, a method has been developed for the semi-automatic merging of MeSH, SNOMED and CMIT. This method takes advantage of the relational model and the synonyms that are given in SNOMED and CMIT, in order to recommend concepts to be merged. An expert interacts with the system to accept or reject the recommendations of the computer. The method would apply equally well to other knowledge bases and is particularly well-suited for knowledge bases that contain tens of thousands of concepts.

Abstracting and Indexing↗
PubMedDate not supplied

Approaches to the construction of a medical informatics glossary and thesaurus.

In a project concerned with establishing a glossary and thesaurus for the medical informatics domain, various approaches to the task have been investigated. The developers take the view that a glossary should be a coherent system of terms, reflecting a coherent system of concepts that underlies a body of knowledge about a domain. A framework for the conceptual analysis of the concepts/terms underlying the domain has been developed. The emphasis of this framework is on how the concepts relate together. This work has given an important insight into how the practical task of establishing well-structured vocabularies for a field can be better achieved. An eclectic approach to term selection was adopted. Criteria for assessing what constitutes good definitions for concepts in a field were examined. Using all these approaches glossaries, thesauri and domain models of the medical informatics field are being developed. Another aspect of our work of particular interest is the development of attributed definitions from which inheritance patterns can be defined.

Data Collection↗