• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.243-250
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• 2006

A recursive relationship is a relationship among entities of the same class. N : M recursive relationships can be used to represent bills of materials. A bill of materials is a special data structure that occurs frequently in manufacturing applications. This data structure is a hierarchy. Most business dimensions have a hierarchical structure. In this study, a design of a hierarchical dimension of the bill of materials type is carried out. As with other N : M relationships, an intersection table that shows pairs of related rows is created, and this table is transformed into a dimension in the OLAP(OnLine Analytical Processing) model. This transformation consists of two tasks: (1)replacing the first column of the intersection table with the lowest level of the dimension: and (2)replacing the second column of the table with the only upper level of the dimension. A case multidimensional information system using the hierarchical dimension is also developed.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.2
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• pp.272-277
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• 2008

Symmerge is a stable minimum storage merging algorithm that needs $O(m{\log}{\frac{n}{m}})$ element comparisons, where in and n are the sizes of the input sequences with $m{\leq}n$. Hence, according to the lower bound for merging, the algorithm is asymptotically optimal regarding the number of comparisons. The Symmerge algorithm is based on the standard recursive technique of "divide and conquer". The objective of this paper is to consider the relationship between m and n for the degenerated case where the recursion depth reaches m-1.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1249-1253
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• 2003

License plate recognition is very important in an automobile society. This is because, since plate detection accuracy has large influence on subsequent number recognition, it is very important. However, it is very difficult to do it, because a background and a body color of cars are similar to that of the license plate. In this paper, we propose a new thresholds determination method in the various background by using the real-coded genetic algorithm (RGA). By using RGA, the most likely plate colors are decided under various lighting conditions. First, the average brightness Y values of images are calculated. Next, relationship between the Y value and the most likely plate color thresholds (upper and lower bounds)are obtained by RGA. The relationship between thresholds decided from RGA and brightness average is aproximate by using the recursive least squares (RLS) algorithm. In the case of plate detection, thresholds are decided from these functions.