[計算] signal-detection的計算
其實我不知道該去哪裡問...因為是實驗法的題目
好像又不屬於統計的範疇@@" 而且看到指數對數就很頭痛 >//////<
所以想請教大家 給我一些指引 :)
Suppose a gang of smugglers were trying illegally to export radioactive
material.In an effort to try to stop this, you monitor with a Geiger
counter every package leaving the country.
For those packages without the radioactive material (NRA)
the number of counts is given approximately by an exponential
distribution.
Letting x equal the number of counts:
f(x|NRA) = e^(-x)
For the package with radio active material (RA)
f(x|RA) = λe^(-λx) 0 < λ < 1.00
(a) What is the likelihood ratio of a package’s containing radioactive
material as opposed to its not containing radioactive material?
(b) If the a priori probability of a package’s containing radioactive
material is 1 in 10^6 , and if
$100 is cost of opening a package and repacking it if does not contain
radioactive material (false alarm -$100)
$10^4 is value of catching a radioactive package (Hit +$10^4)
$10^6 is cost of letting a radioactive package through (Miss -$10^6)
$0 is the value of letting a nonradioactive package through
(correct rejection +$0)
What value of likelihood ratio should lead one to ask that the package
be opened?
(c) If =1/6, what value of x would one need to attain that value of
likelihood ratio in (b)?
Suppose your budge director gives you $300,000 per year, so that you can
afford to open 3000 packages per year even if none is radioactive.
(d) What number of counts would you use on the assumption that 10
packages are processed each year?
(e) What is your probability of detecting a radioactive package if=1/8?
我很努力的想 也只可能知道第一提可能的解答是什麼
我會再努力看看 也希望板上的大家可以給我一點指引..
真的很感謝你們^^
--
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 125.232.114.148
--
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 125.232.114.148
※ 編輯: yuu0826 來自: 125.232.114.148 (04/26 14:13)
※ 編輯: yuu0826 來自: 125.232.112.5 (04/27 11:30)
討論串 (同標題文章)
完整討論串 (本文為第 1 之 2 篇)：