Sangduck Lee

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A questionnaire survey was carried out to examine the sleep habits and excessive daytime sleepiness (EDS) of 3871 high school students with a mean age of 16.8 years in Korea. The results showed that mean total sleep time was 6.3 h/day for male students and 6.5 h/day for female students, which may be insufficient for adolescence during puberty. The overall(More)
  • Cheoljoo Jeong, Kangho Kim, Youngbae Oh, Yeondae Chung, Sangduck Lee
  • 1999
It is common in the behavior of business applications to check whether an actor has an authorization to perform some actions on a specific piece of information. Though vast amount of research efforts were devoted to devising such an authorization mechanism, through a logical approach or at the level of systems software [1, 3, 4], there have been few results(More)
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