Vol. 38 No. 1 (2006)

Randall-Sundrum single brane system (RS II) is investigated systematically, with an emphasis of the effective equation of motion on the brane, by using a low energy expansion method (gradient expansion method) in the bulk. Through the junction condition, we deduce in the zeroth order fine tuning for RS model. The modified Einstein equation, as well as Friedmann equation with dark energy radiation on the brane is derived from the first order expansion. We also clarify the emergence of the AdS/CFT correspondence for the case of the higher order expansion in a low energy iteration scheme.

In this paper, we discuss simulation and experimental study of the application of Least Mean Square (LMS) based adaptive filter algorithm in active noise control. A number of adaptive filter algorithm based on LMS are investigated, namely Preconditioned Least Mean Square (PLMS), Filtered-reference LMS (FxLMS) and two variants of Filtered-error LMS (FeLMS) algorithms. Active noise control simulation for attenuating recorded blower noise is performed. In case of active noise control experiment, a disturbance is generated by adding three sinus waves with different amplitudes and phases using…

Transmission coefficient of an electron incident on a heterostructure potential with nanometer-thick trapezoidal barrier grown on anisotropic materials are derived by solving the effective-mass equation including off-diagonal effective-mass tensor elements. The boundary condition for an electron wave function (under the effective-mass approximation) at a heterostructure anisotropic junction is suggested and included in the calculation. The analytic expressions are applied to the Si(110)/Si0.5Ge0.5/Si(110) heterostructure, in which the SiGe barrier thickness is several nanometers. It is…

This paper present the results of the mathematical model study on the relation between rain fall pattern, surface run off flows and land erodibility of a catchment area and river sedimentation. The influences of catchment area characteristics such as land use, soil behavior, topography condition and other related physical condition is encountered. Surface flow assessment is done at each sub catchment area by using mathematical model named ANSWER. Case study on Cipeles Catchmen area had shown that land use and rain fall pattern are the main parameter. Good agreement between model result and…

Since 1977, DES officially became America encryption algorithm. And then this algorithm spreads over the world to be used in banking, financial industries, and economics. Because of the short of the key, in 2001, DES is replaced by AES. One of the most important problem in cryptology is how to prove the security of algorithm against cryptanalysis. In this paper, we will discuss differential attack to examine the security of DES, AES and AE1. AE1 is block cipher that we proposed. Although differential attack has been proposed since 1990, all of cryptographers in the world still use it to…