二次突变假说是由诺丁在1953年提出的,他发现似乎随着年龄的增长,患有癌症的概率有上升.对这种现象有一种解释,即癌症的发生需要多个突变的累积. 克努森在1971通过研究正式地提出该观点.他对具有遗传性的眼癌进行研究,发现除了遗传性的眼癌外,还有零星的正常人也会患有眼癌,只是正常人患有眼癌的时间会大大推迟. 克努森认为带有遗传性眼癌的小孩,在出生时就已经携带了第一次突变,而后面的第二次突变将在很短的时间内到来,从而引发眼癌.而正常人的第一次突变可能要经过很长的时间才会形成,然后再第二次突变,从而引…

假设检验(Hypothesis Testing) 1. 什么是假设检验呢? 假设检验又称为统计假设检验,是数理统计中根据一定假设条件由样本推断总体的一种方法. 什么意思呢,举个生活中的例子:买橘子(借用http://www.360doc.com/content/16/0617/08/31718185_568436468.shtml) 当我们去买橘子的时候,无论甜不甜,老板都会说:"挺甜的,不信拿一个尝尝".我们随手拿一个(这就相当于抽样),此时我们对于这些橘子甜或不甜的判断全基于这个橘…

Null hypothesis usually express the phenomenon of no effect or no difference. TypeⅠerror is the incorrect rejection of a true null hypothesis.  That is, no difference is taken as difference. Type Ⅱ error is incorrectly retaining a false null hypothes…

1.Null Hypothesis Overview 零假设,H0是普遍接受的事实;这与备择假设(alternate hypothesis)正好相反.研究人员努力否定.驳斥零假设.研究人员提出了另一种假设(alternate hypothesis),他们认为这种假设可以解释一种现象,然后努力拒绝零假设. The null hypothesis, H0 is the commonly accepted fact; it is the opposite of the alternate hypoth…

Hypothesis Testing What's Hypothesis Testing(假设检验) Hypothesis testing is the statistical assessment of a statement or idea regarding a population. A hypothesis is a statement about the value of a population parameter level developed for the purpose o…

Case Study The case study Physicians' Reactions sought to determine whether physicians spend less time with obese patients. Physicians were sampled randomly and each was shown a chart of a patient complaining of a migraine headache. They were then as…

这里先再次提出我们利用aggregation获取更好性能的Hypothesis G所涉及的方法:blending,就是在得到g_set之后进行融合:learning呢?就是在线online的获取g并融合.以下就是关于整个aggregation所涉及到的方法总结: 当中Bagging.AdaBoost我们都已经探讨.它们各自是基于uniform(voting / average)和non-uniform(linear)的aggregation type,那么以下就開始介绍一个基于condition…

time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output PolandBall is a young, clever Ball. He is interested in prime numbers. He has stated a following hypothesis: "There exists such a positive integ…

Hypothesis是Python的一个高级测试库.它允许编写测试用例时参数化,然后生成使测试失败的简单易懂的测试数据.可以用更少的工作在代码中发现更多的bug. 安装 pip install hypothesis 如何设计测试数据 通过介绍也许你还不了解它是干嘛的,没关系!我们举个例子. 首先,我有一个需要测试的函数: def add(a, b): """实现加法运算""" return a + b 测试代码是这样的: import unitt…

Computational biological hypothesis generation using "-omics" data Forming biological hypotheses are crucial to the success of scientific investigations in modern biology and medicine. To generate good biological hypotheses efficiently, computat…