Katsuhiko Takabayashi

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The hepatitis temporal database collected at Chiba university hospital between 1982--2001 was recently given to challenge the KDD research. The database is large where each patient corresponds to 983 tests represented as sequences of irregular timestamp points with different lengths. This paper presents a temporal abstraction approach to mining knowledge(More)
A machine learning technique called Graph-Based Induction (GBI) efficiently extracts typical patterns from graph-structured data by stepwise pair expansion (pairwise chunking). It is very efficient because of its greedy search. Meanwhile, a decision tree is an effective means of data classification from which rules that are easy to understand can be(More)
This paper proposes a novel decision tree for a data set with time-series attributes. Our time-series tree has a value (i.e. a time sequence) of a time-series attribute in its internal node, and splits examples based on dis-similarity between a pair of time sequences. Our method selects, for a split test, a time sequence which exists in data by exhaustive(More)
OBJECTIVES The prevalence of electronic medical record in Japan varies according to the size of the hospital which is 62.5% in major hospitals, 21.7% in medium, 9.1% in small size hospitals, and 16.5% in clinics. The complete paperless system is very limited, though some major hospitals are aiming at this system. Several regional network systems which(More)
Worldwide populations are aging and countries have to prepare for the effects of demographic change in health care. Health information exchange (HIE), which is the process of moving patient information across health care providers electronically, can help overcome health data fragmentation and open opportunities to improve patient care in terms of quality,(More)