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WTO 체제의 출범과 무역ㆍ환경논의 동향 (상)

  • Kim, Jun-Han
    • Korea Petroleum Association Journal
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    • no.7 s.173
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    • pp.80-92
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    • 1995
  • 이 자료는 지난 5월 25일 상공회의소에서 열린 '국내외 환경동향과 한국산업의 선택'에 관한 토론회에서 발표된 내용을 옮긴 것이다. <편집자 주>

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Selectivity Estimation for Multidimensional Sequence Data in Spatio-Temporal Databases (시공간 데이타베이스에서 다차원 시퀀스 데이타의 선택도추정)

  • Shin, Byoung-Cheol;Lee, Jong-Yun
    • Journal of KIISE:Databases
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    • v.34 no.1
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    • pp.84-97
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    • 2007
  • Selectivity estimation techniques in query optimization have been used in commercial databases and histograms are popularly used for the selectivity estimation. Recently, the techniques for spatio-temporal databases have been restricted to existing temporal and spatial databases. In addition, the selectivity estimation techniques focused on time-series data such as moving objects. It is also impossible to estimate selectivity for range queries with a time interval. Therefore, we construct two histograms, CMH (current multidimensional histogram) and PMH (past multidimensional histogram), to estimate the selectivity of multidimensional sequence data in spatio-temporal databases and propose effective selectivity estimation methods using the histograms. Furthermore, we solve a problem about the range query using our proposed histograms. We evaluated the effectiveness of histograms for range queries with a time interval through various experimental results.