离散数学是计算机出现以后迅速发展起 来的一门数学分支。计算机科学就是算 法的科学，而计算机所处理的对象是离 散的数据，所以离散对象的处理就成了 计算机科学的核心，而研究离散对象的 科学恰恰就是离散数学

1. is absolutely summable, 2. has finite energy

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

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

The logical extension of discrete mass systems is one of an infinite number of masses. In the limit, this is a continuous system. Take the generalized beam-column as a generic representation:

Generating functions Generating functions are one of the most surprising, useful, and clever inventions in discrete math. Roughly speaking, generating functions transform problems about se- quences into problems about functions. This is great because weve got piles of mathe- matical machinery for manipulating functions. Thanks to generating functions, we can

Phase and Group Delays 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 0(@) =arg{()} of the system

Introduction The consumption-based model as a complete answer to most asset pricing question in principle, does not work well in practice; This observation motivates effects to tie the discount factor m to other data; Linear factor pricing models are most popular models of this sort in finance; They dominate discrete-time empirical work