Hyunja Lee

Building an operational product ontology system

A base of clearly defined product information is a key foundation for an e-commerce system. The manipulation and exchange of semantically enriched and precise product information can enhance the quality of an e-commerce system and offer a high level of interoperability with other systems. Product information consists of product attributes and the relationships between products. Product categorization (or classification) is one type of such relationships. Ontology can play an important role in the formalization of product information. Although the idea of utilizing ontology for e-Catalogs has been raised before, we are yet to find an operational implementation of applying ontology in the domain. In this paper, we report on our recent effort to build an operational product ontology system for a government procurement service. The system is designed to serve as a product ontology knowledge base; not only for the design and construction of product databases but also for search and discovery of products. Especially, the keyword-based searching over product ontology database demands different techniques from those over conventional document databases or relational databases, and should be designed to reflect particular characteristics of product ontology. We also introduce some other issues that we have experienced in the project, and those issues include product ontology modeling, ontology construction and maintenance, and visualization. Our work presented herein may serve as a reference model for similar projects in the future.

Ontological modeling of e-catalogs using EER and description logics

Electronic catalog contains rich semantics associated with products, and serves as a challenging domain for ontology application. Ontology is concerned with the nature and relations of being. It can play a crucial role in e-commerce as a formalization of e-Catalogs. Description logics provide a theoretical core for most of the current ontology languages. In this paper, we present an ontological model of e-Catalogs. Our goal is to represent the semantic information of e-Catalog in a conceptual model, and then to construct a formally sound ontology. We take an extended entity relationship approach to denote the fundamental set of modeling constructs, and present corresponding description logic representation for each construct. Additional semantic knowledge can be represented directly in description logic.

Practical issues for building a product ontology system

A base of clearly defined product information is a key foundation for an e-commerce system. The manipulation and exchange of semantically enriched and precise product information can enhance the quality of an e-commerce system and offer a high level of interoperability with other systems. Product information consists of product attributes and the relationships between products. Product categorization (or classification) is one type of such relationships. Ontology can play an important role in the formalization of product information. Although the idea of utilizing ontology for e-catalogs has been raised before, we are yet to find an operational implementation of applying ontology in the domain. In this paper, we report on our recent effort to build an operational product ontology system for the government procurement service. The system is designed to serve as a product ontology knowledge base; not only for the design and construction of product databases but also for search and discovery of products. We introduce some of the issues that we have experienced in the project, so that our work may serve as a reference model for similar projects in the future.

PROMOD: a modeling tool for product ontology

Product ontology is often constructed by explicating the domain ontology in a formal ontology language. The OWL Web Ontology Language has been positioned as a standard language. It requires technical expertise to directly represent the domain in OWL. An alternative way is to let a domain expert provide a conceptual representation of the domain, and to mechanically translate it into the corresponding OWL codes. We have developed a modeling tool called PROMOD to achieve this process in the product domain. We employ an Extended Entity-Relationship for conceptual model, enriched with modeling elements specialized for the product domain. We present how each element may be technically represented in OWL. We also provide a modeling scenario to demonstrate the practical feasibility of the tool in the field.

Conceptual and formal ontology model of e-catalogs

Ontology concerns with the nature and relations of being. Electronic catalog contains rich semantics associated with products, and serves as a challenging practical domain for ontology application. It is beneficial to model e-Catalogs based not only on the definition of each product class and the taxonomic hierarchy of classes but also on the associated semantic knowledge. Ontology can play an important role in e-Commerce as a formalization of e-Catalogs. However, an ontological modeling should not be technically too complicated to represent and comprehend the e-Catalog domain for a domain expert who has little knowledge in the formal language. In this paper, we present an ontological representation of e-Catalogs, which is both conceptual and formal. We take an Extended Entity Relationship approach to denote the fundamental set of modeling constructs, and present corresponding description logic representation for each construct. We also consider the modeling language to be reasonably practical with regard to its expressiveness and complexity. We illustrate sample e-Catalog modeling scenarios to demonstrate the practical feasibility of our modeling approach.

A pragmatic approach to model and exploit the semantics of product information

Recently researchers have tried to apply ontology to the product information domain. From a practical point of view, a key problem to streamline this trend is how to make a product ontology database operational. Technical solutions should consider the characteristics that a pragmatic product ontology database contains; first, the database size is quite huge, and second, ontological manipulation and utilization should be realistically feasible. We recently engaged in a project to build an operational product ontology system. The system is designed to serve as a product ontology knowledge base, not only for the design and construction of product databases but also for the search and discovery of products. From the insights gained through this project, we believe that ontological modeling and its implementation on an operational database, as well as the building applications which exploit ontological benefits, are the most important facets towards the successful deployment of a practical product ontology system. As such, searching techniques should take into account the features of an underlying ontological model especially with product searching being one of the most popular applications within product information systems. In this paper, we present these two issues; product ontology modeling and searching techniques. Although our work presented herein may not be the only way to build an operational product ontology database, it may serve as an important reference model for similar projects in future.

Pivoted table index for querying product-property-value information

The query for triple information on product -attribute (property)-value is one of the most frequent queries in e-commerce. Storing the triple, schema vertically is effective for avoidance of sparse data and schema evolution. However, conventional horizontal schema often shows better query performance when properties are queried as groups clustered by product. Therefore, we propose vertical schema as a primary table structure for the triple information in RDBMS and a pivoted table index created from the basic vertical table. This index is beneficial to performance of the frequent pattern query on the group properties associated with each product class.

Conceptual Modeling of Product Information in e-Commerce

A well developed product information repository is an important part of an e-Commerce system. Product information contains rich semantics associated with product attributes and the relationships between products. We have presented an ontological model of product information which is both conceptual and formal. We employed extended entity relationship as a structural anchor for the conceptual and pictorial representation of the formal model. In this paper, we illustrate modeling scenarios to demonstrate the practical feasibility of our modeling approach in the domain. In addition, we survey the recent works on conceptual modeling and ontological approaches of product information.