Electrical Engineering - Signals and systems

- Discuss concepts but not share homework/code

First a few of my notes, then some questions for you.

- https://en.wikipedia.org/wiki/Zero-order_hold

The zero-order hold (ZOH) is a mathematical model of the practical signal reconstruction done by a conventional digital-to-analog converter (DAC). That is, it describes the effect of converting a discrete-time signal to a continuous-time signal by holding each sample value for one sample interval. - https://en.wikipedia.org/wiki/Piecewise_linear_function

In mathematics, a piecewise linear function is a real-valued function defined on the real numbers or a segment thereof, whose graph is composed of straight-line sections. It is a piecewise-defined function, each of whose pieces is an affine function. - http://www.math.ubc.ca/~cass/courses/m309-03a/a1/olafson/affine_fuctions.htm

An affine function is a function composed of a linear function + a constant and its graph is a straight line. The general equation for an affine function in 1D is: y = Ax + c. An affine function demonstrates an affine transformation which is equivalent to a linear transformation followed by a translation.Q: what does it mean "parallel lines remain parallel" under an affine transformation?

- http://www.vac-eng.com/modules/DownloadManager/download.php?alias=leak-rate-definition

LEAK RATE DEFINITION.pdf

Leak Rate Q = V dp/dt

dt: time, dp: difference between internal and external pressure

V: volume of container

- So Q=V dF/(dA.dt), so increase in Area results in decrease in leak rate. So order of leak rate from smallest to largest is 4,1,3,2
- r1(t) is proportional to h1(t) since V=A.h1 (A is area) and r1(t) is another name for Q