Diagnostic medical sonography (DMS) uses. high frequency sound waves to produce images. (sonograms) of structures such as the liver, heart. or unborn baby that can be visualized on a video. monitor. Sonography is often referred to as. âultrasoundâ or âultrasonographyâ. Sonography. can be used to examine many parts of the body. including organs in the abdomen, the breast, the. uterus and ovaries, the prostate gland, the heart. and blood vessels.
principle of superposition - the displacement of any point due to the superposition of wave systems is equal to the sum of the displacements of the individual waves at that point; the principle of superposition is the basis of the wave theory of light. Huygens' principle of superposition.
Exponents, scale invariance and universality. One of the key properties of power laws is their scale invariance. Suppose that for a given power law, , we change the length scale of our observation from to, where is a constant. Then, which leaves the power law intact, changing only the constant of proportionality. power law is a mathematical relationship between two quantities where one is proportional to a power of the other: that is, of the form, where and are constants, with being referred to as the exponent.