• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1191-1200
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• 2009

The replicas in the Grid database is utilized for a lot of application services. And for deferent services or for deferent information depends on location, the access frequency of each replica is dissimilar. When one replica is stored in many nodes, each replicas applies the week-consistency in the grid computing environment. Especially, when a node work load or operation capacity is varied from others, the replica management would cost expansive. Therefore, this paper proposed the Update Method based on Dynamic Access-Frequency Tree. The dynamic access-frequency tree is pre-constructed by grouping nodes based on each nodes access frequency to manage the replica efficiently and avoid unbalance replica tree. The performance evaluation shows the proposed methods support more quick update than current methods.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.361-367
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• 2010

The use of antifouling(AF) paints is the effective method for the protection of underwater structures from the development of marine fouling organisms. The ban on harmful substances in antifouling paints requires the development of new antifouling strategies although Tributyitin (TBT) compound had been used extensively as an active ingredient Alternatives should be as effective as conventional paints but have lower toxicity. In the present study, a TBT-free self-polishing (Cu SPC) AF paint containing $Cu_2O$, a Cu free SPC AF paint, and a Foul-release silicone AF paint, which were commercially available, were examined to investigate environmental erects of leakage waters employing Sebastes shlegeli and Artemia. Survival rates were inversely proportional to the concentration of leakage waters from AF paints and the acute toxicity of SPC AF paints was relatively higher than that of foul release AF paints.