**8. Appendix II (Symbols)**

254 Acoustic Waves – From Microdevices to Helioseismology

The depth of penetration of a shear wave (δ) in a Newtonian medium is given by the

1

1

*m m*

arctan

 η (2)

 ω

1/4 <sup>2</sup>

() 2

*n n m nm m Sin C C*

*Chromosome:* Each individual has a number of chromosomes that represent each parameter

*Genes:* Each chromosome contains a fixed number of genes, the number of genes per chromosome determine the resolution of the total solution. The number of genes per chromosome is mostly determined by the broadness of the range in which each

*Fitness:* Every individual has to be weighed according to its fitness. The individual fitness value determines its survival and breeding probability. A higher fitness individual has

As seen in fig. 11, the biological process consist of a piezoelectric layer (MTSM sensor) and a non-piezoelectric biological layer. In this model, each layer of load can be represented as a

Fig. 11. Mason model representation of non-piezoelectric layers loaded on piezoelectric plate

<sup>=</sup> − − <sup>+</sup>

2 2

ω η

ρ

**7. Appendix I** 

equation shown below:

n = harmonic number

chromosome lies.

higher probability of survival.

T-network of impedances.

**C. Mason's transmission line model** 

**A. The depth of penetration of a shear wave (δ)** 

ω

*n*

**B. Basic terminologies of a genetic algorithm** 

(i.e. variables to be determined) of the problem.

*Individual:* A solution to the problem is called an individual. *Population:* The total number of solutions is called population.

δ

ρm = density of medium (kg/m3), ηm = viscosity of medium (kg/m.s), Cm = stiffness of medium (N/m2), ω = angular frequency (rad/s) and

F1 = input force (N) F2 = output force (N) v1 = input particle velocity (m/s) v2 = output particle velocity (m/s) A = area of active electrode of MTSM (m2) k = propagation constant (m-1) d = thickness (m) Z = acoustic impedance (acoustic ohm) I = current (C) C0 = static capacitance of MTSM (F) φ: transformer ratio
