Pat Molholt

Methodology for evaluating image-segmentation algorithms

The purpose of this paper is to describe a framework for evaluating image segmentation algorithms. Image segmentation consists of object recognition and delineation. For evaluating segmentation methods, three factors - precision (reproducibility), accuracy (agreement with truth, validity), and efficiency (time taken) - need to be considered for both recognition and delineation. To assess precision, we need to choose a figure of merit, repeat segmentation considering all sources of variation, and determine variations in figure of merit via statistical analysis. It is impossible usually to establish true segmentation. Hence, to assess accuracy, we need to choose a surrogate of true segmentation and proceed as for precision. In determining accuracy, it may be important to consider different landmark areas of the structure to be segmented depending on the application. To assess efficiency, both the computational and the user time required for algorithm and operator training and for algorithm execution should be measured and analyzed. Precision, accuracy, and efficiency are interdependent. It is difficult to improve one factor without affecting others. Segmentation methods must be compared based on all three factors. The weight given to each factor depends on application.

A Comprehensive Information Resource on Traditional, Complementary, and Alternative Medicine: Toward an International Collaboration

OBJECTIVES A prototype for a comprehensive information resource for traditional complementary and alternative medicine (TCAM) has been developed to fill the considerable needs of a broad audience for worldwide access to TCAM information. The proposed resource is to be a comprehensive, vocabulary-controlled, integrated, standardized, multimedia information resource for TCAM. It will facilitate international cooperation, promote synergistic development of individual resources, promote dissemination of TCAM knowledge, and map the interrelationships among the TCAM traditions. METHODS We organized two workshops for representatives of international databases that contain significant information on various aspects of alternative medicine. For the first workshop, we prepared and demonstrated a prototype named Complementary and Alternative Medicine Digital Library (CAMed) to illustrate the anticipated structure, content, and functionality of the comprehensive resource. We then constructed a second prototype to demonstrate the possibilities of searching across the collaborating databases and presented it to the representatives at the second workshop. OUTCOMES Representatives of nine international databases attended the two workshops, in Bangalore, India (1998), and in Seoul, Korea (1999). We presented the prototypes at the workshops. Prototype I uses a Web interface, and supports browsing and searching from a variety of access points. Prototype II demonstrates a functional system that provides simultaneous access to selected represented databases by searching thesauri of these databases through our system. The group formalized itself as the International Collaboration for Information on Complementary and Traditional Medicine (IC2TM) with a goal of fully realizing the potential of the project.

The role of the «art and architecture thesaurus» in communicating about visual art

The paper addresses the ways in which computerization and a thesaurus like the Art and Architecture Thesaurus (AAT) influence the organization, description, and understanding of the visual arts. It discusses these issues from the point of view of the AAT and considers how its structure and content serve as a bridging mechanism between the many different manifestations of the visual arts and the different types of organizations serving the viewers of art, whether as students, scholars, collections managers, or the enjoying public. This paper shows how a knowledge base like the AAT helps this variety of users develop approaches to the visual arts and suggests that the special nature of dealing with image rather than text influences how the thesaurus is structured and applied

The Art and Architecture Thesaurus: Controlling Relationships through Rules and Structure

The Art and Architecture Thesaurus (AAT) staff developed a set of associative, interconcept relationships to interconnect terminology contained in 33 hierarchies. Each of the 20 relationships is tightly defined and is applied under strict rules. The result benefits the user by providing reliable, standardized links between concepts. This chapter describes the logic, methodology, and impact of the AAT approach to relationships.