Seunghyun Im

Learn More
Action rule is an implication rule that shows the expected change in a decision value of an object as a result of changes made to some of its conditional values. An example of an action rule is ‘credit card holders of young age are expected to keep their cards for an extended period of time if they receive a movie ticket once a year’. In this case, the(More)
This paper discusses data confidentiality in a Distributed Knowledge Discovery System (DKDS) . In particular, we provide a method that protects values of confidential attributes from being reveled by Chase algorithm [8] using reducts [13]. The method presented in this paper is intended for use in DKDS that the set of rules used by Chase algorithm is not(More)
An action is defined as controlling or changing some of attribute values in an information system to achieve desired result. An action reduct is the minimal set of attribute values distinguishing a favorable object from other objects. We use action reducts to formulate necessary actions. The action suggested by an action reduct induces changes of decision(More)
Knowledge based query answering system takes advantage of data mining techniques to provide answers to user queries that involve incomplete or foreign attribute values. However, such process may cause a security issue when the system contains confidential data required to be protected. The confidential data as well as other values can be treated as missing(More)
Recently, the main topic in e-learning domain and industry is called digital convergence whose core demand is OSMU (One Source Multi Use). However, there exists so many learning contents in Web, and with the development of new learning content which must adapt the new learning environment, the problem about cost and time appears. So in this paper we design(More)
Information and Communication Technology (ICT) has been considered an important avenue for ensuring patients' good health, full social participation, and independent living as long as possible through their entire life span. In the last decade, various ICT solutions were developed to facilitate medical organizations in sharing critical information about(More)