The output y[n] of a frequency-selective LTI discrete-time system with a frequency response exhibits some delay relative to the input x[n] caused by the nonzero phase response of the system

29.1 Introduction 29.2 Fly development uses a cascade of transcription factors 29.3 A gradient must be converted into discrete compartments 29.4 Maternal gene products establish gradients in early embryogenesis 29.5 Anterior development uses localized gene regulators

一、承载信息的函数 二、模拟信号是连续的(continuous)，数字信号是离散的(discrete)

Time-Domain Representation Signals are represented as sequences of numbers, called samples Sample value of a typical signal or sequence denoted as x[n] with n being an integer in the range x[n] defined only for integer values of n and undefined for non-integer values of n

Some disorders result when a mutation causes the product of a single gene to be altered or missing. These disorders are inherited in simple patterns similar to or identical with those described by Mendel for certain discrete characteristics in garden peas. Therefore, it’s also called Mendelian diseases

1. Continuous-time system 2. Discrete-time system

1. is absolutely summable, 2. has finite energy

1 The eigenvalue distribution function For an N × N matrix AN , the eigenvalue distribution function 1 (e.d.f.) F AN (x) is defined as F AN (x) = Number of eigenvalues of AN ≤ x . (1) N As defined, the e.d.f. is right continuous and possibly atomic i.e. with step discontinuities at discrete points. In practical terms, the derivative of (1), referred to as the (eigenvalue) level density, is simply the

Biological Membranes and Transport Biological membranes are made of a lipid bilayer decorated with various proteins and/or carbohydrates. Membranes define the external boundaries of cells and regulate the molecular traffic across that boundary In eukaryotic cells, membranes also divide the internal space into discrete compartments to segregate processes and components

Chemists use spectroscopy (Ir, UV-Vis, NMR) to determine molecular structure. spectroscopy: technique that measures the amount of radiation a substance absorbs at various wavelengths(based on the quantization of molecular energy levels Molecules exist in quantized energy states (rotational, vibrational, and electronic quantum states) Molecules absorb discrete amounts of energy(ae)and are excited to higher