Numb3rs 中提到的数学问题

 1 P versus NP problem：

In this theory, the class P consists of all those decision problems (defined below) that can be solved on a deterministic sequential machine in an amount of time that ispolynomial in the size of the input; the class NP consists of all those decision problems whose positive solutions can be verified in polynomial time given the right information, or equivalently, whose solution can be found in polynomial time on a non-deterministic machine.^[5] Arguably, the biggest open question in theoretical computer science concerns the relationship between those two classes:

Is P equal to NP?

In a 2002 poll of 100 researchers, 61 believed the answer is no, 9 believed the answer is yes, 22 were unsure, and 8 believed the question may be independent of the currently accepted axioms, and so impossible to prove or disprove.

 

http://en.wikipedia.org/wiki/P_versus_NP_problem

 

2 SIR model

An SIR model is an epidemiological model that computes the theoretical number of people infected with a contagious illness in a closed population over time. The name of this class of models derives from the fact that they involve coupled equations relating the number of susceptible people , number of people infected , and number of people who have recovered . One of the simplest SIR models is the Kermack-McKendrick model.

The Season 1 episode "Vector" (2005) of the television crime drama NUMB3RS features SIR models.

 

3 马尔科夫链：

一个由随机值组成的序列，在其中任意时间的数值概率都依赖于前一时间点的数值。马尔科夫链中的控制因素，被称为可变概率