Toshiaki Yoshino

A knowledge-based approach to design a portable natural language interface to database systems

This paper presents a knowledge-based approach to design a portable natural language interface to database systems, called KID (Knowledge-based Interface to Database systems). To free the user from the need to know about query languages and databases, and to allow the user to access databases in natural language, KID incorporates a knowledge base called the world model (WM), which contains a domain model, linguistic knowledge, and database mapping knowledge. To transport KID to a new domain, the user has only to build a new WM for the domain; the WM is easy for the user to define and understand. KIDs processing of the users query using the WM is transparent enough to the user to enable easy debugging of the WM. Encapsulating all the domain-specific knowledge into the WM makes KID portable. This paper discusses the WM design and KIDs knowledge-based processing of a query using the WM.

ImpactScale: Quantifying change impact to predict faults in large software systems

In software maintenance, both product metrics and process metrics are required to predict faults effectively. However, process metrics cannot be always collected in practical situations. To enable accurate fault prediction without process metrics, we define a new metric, ImpactScale. ImpactScale is the quantified value of change impact, and the change propagation model for ImpactScale is characterized by probabilistic propagation and relation-sensitive propagation. To evaluate ImpactScale, we predicted faults in two large enterprise systems using the effort-aware models and Poisson regression. The results showed that adding ImpactScale to existing product metrics increased the number of detected faults at 10% effort (LOC) by over 50%. ImpactScale also improved the predicting model using existing product metrics and dependency network measures.

A natural language interface using a world model

Databases are nowadays used by varied and diverse users, many of whom are unfamiliar with the workings of a computer, but who, nevertheless, want to use those databases more easily. Rising to meet this demand, authors are developing a Japanese language interface, called KID, as a database front-end system. KID incorporates a world model representing application and database knowledge to help make databases easier to use. KID has the following features: (1) parser extendability and robustness, (2) independence from the application domain, (3) ease of knowledge editing, (4) independence from the database. This paper focuses on the first three features. KID has already been applied to the fields of housing, sales, and drug testing, thus confirming its transportability and practicality.