Abstract: A surgery optimizing method performed by a computer is provided. The method includes generating a plurality of genes corresponding to a surgical procedure based on the surgical procedure composed of at least one detailed surgical operation, performing virtual surgery on each of the plurality of genes to evaluate whether surgery is optimized, selecting at least one gene among the plurality of genes based on the evaluation result to apply a genetic algorithm, and applying the genetic algorithm to generate a new gene and deriving an optimal surgical procedure based on the new gene.

Abstract: A noiseproof vent valve for a fuel tank is provided. A damping member installed in the vent valve has at least two elastic pieces, preferably the four elastic pieces. The movement of the float is absorbed by elastic deformation of the elastic pieces, and thus the float is prevented from coming into contact with a lower end forming the bottom of a valve body. However excessively the float fluctuates, no “clicking” contact noise occurs at the vent valve. As a result, the merchantability of a hybrid vehicle sensitive to low noise can be greatly increased.