• Journal of Information Technology Application
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• v.3 no.3
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• pp.1-24
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• 2001

This paper introduces the genetic programming algorithm(GP), which can approximate highly nonlinear functions, as a tool for the modeling of response surfaces. When the response surfaces is approximated, the very small or minimal teaming set should be used, and thus it is almost certain that GP trees will show overfilling that must be avoided at all costs. We present a novel method, calledDDBS(DirectionalDerivative-Based Smoothering), which very effectively eliminates the unwanted behaviors of GP trees such as large peaks, oscillations, and also overfitting. Four illustrative numerical examples are given to demonstrate the performance of the genetic programming algorithm that adopts DDBS.

• Toxicological Research
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• v.16 no.2
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• pp.151-161
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• 2000

The Three months subacute toxicity of water soluble dimethyl dimethoxy biphenylate derivative (DDB-S), newly formulated therapeutic agent for hepatitis, was invesgated in SD rats. The body weight and clinical signs were observed after intravenous injection of DDBs at doses of 57, 75 and 100 mg/kg/day for three months. Decrease in motor activity and tremor were observed above 75mg/kg treated groups. Statistically significant changes at serum biochemical analysis were found in some group, how-ever, those changes were within the normal range and had no relationship with dosage. There was no abnormal morphological and pathological findings in relation to DDB-S treatment. The no observable adverse effect level of DDB-S in rats was estimated to be 57 mg/kg/day in this study.