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We numerically analyze the AC electric field around a droplet placed on an insulator-covered electrode. The time-averaged effective electrical wetting tension, which is a function of AC frequency, is computed by integrating the Maxwell stress. The computed wetting tension is compared with the experimental result converted from the separately obtained contact-angle data. There is a good agreement between the two results at a low-frequency range and a qualitative agreement at a high-frequency range. Interestingly, the numerical results show that the electric-field strength decreases remarkably in the insulating layer near the TCL as the AC frequency increases. This decrease may account for the delay of the dielectric breakdown of an insulating layer in the AC case, which could be related to the contact-angle saturation phenomenon.

Three time memory tradeoff algorithms are compared in this paper. Specifically, the classical tradeoff algorithm by Hellman, the distinguished point tradeoff method, and the rainbow table method, in their non-perfect table versions, are treated.We show that, under parameters and assumptions that are typically considered in theoretic discussions of the tradeoff algorithms, Hellman and distinguished point tradeoffs perform very close to each other and that the rainbow table method performs somewhat better than the other two algorithms. Our method of comparison can easily be applied to other situations, where the conclusions could be different.The analysis of tradeoff efficiency presented in this paper does not ignore the effects of false alarms and also covers techniques for reducing storage, such as ending point truncations and index tables. Our comparison of algorithms takes the success probabilities and pre-computation efforts fully into account.