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conditional Gaussian model

Last edited: August 8, 2025

Say you have one continuous variable \(X\), and one discrete variable \(Y\), and you desire to express the probability of \(X\) conditioned upon \(Y\) using a gaussian model:

\begin{equation} p(x|y) = \begin{cases} \mathcal{N}(x \mid \mu_{1}, \sigma_{1}^{2}), y^{1} \\ \dots \\ \mathcal{N}(x \mid \mu_{1}, \sigma_{1}^{2}), y^{n} \\ \end{cases} \end{equation}

conditional plan

Last edited: August 8, 2025

conditional plan is a POMDP representation technique. We can represent a conditional plan as a tree.

toy problem

crying baby POMDP problem:

  • actions: feed, ignore
  • reward: if hungry, negative reward
  • state: two states: is the baby hungry or not
  • observation: noisy crying (she maybe crying because she’s genuinely hungry or crying just for kicks)

formulate a conditional plan

we can create a conditional plan by generating a exponential tree based on the observations. This is a policy which tells you what you should do given the sequence of observations you get, with no knowledge of the underlying state.

conditions in the Great Depression

Last edited: August 8, 2025

There are many condition in the Great Depression caused

  • by 1932, 1/4 had no work
  • emigration exceeded immigration
  • decrease in American birth
  • increase of mental illness and suicide
  • people create Hooverviles
  • movies and radio became much more popular

confidence interval

Last edited: August 8, 2025

proportional confidence intervals

We will measure a single stastistic from a large population, and call it the point estimate. This is usually denoted as \(\hat{p}\).

Given a proportion \(\hat{p}\) (“95% of sample), the range which would possibly contain it as part of its \(2\sigma\) range is the \(95\%\) confidence interval.

Therefore, given a \(\hat{p}\) the plausible interval for its confidence is:

\begin{equation} \hat{p} \pm z^* \sqrt{\frac{\hat{p}(1-\hat{p})}{n}} \end{equation}

where, \(n\) is the sample size, \(\hat{p}\) is the point estimate, and \(z*=1.96\) is the critical value, the z-score denoting \(95\%\) confidence (or any other desired confidence level).

confluence

Last edited: August 8, 2025

Could a different choice of evaluation order change the terminating result of the program; note that this says nothing about whether or not particular evaluation order terminates.

constituents

requirements

A set of rewrite rules is confluent if for any expression \(E_0\), should \(E_0 \to^{* } E_1\) and \(E_0 \to^{* } E_2\), then there exists some \(E_3\) such that \(E_1 \to^{*} E_3\) and \(E_2 \to^{ *} E_3\)

Why this instead of saying we will end up at one state after all evaluations? Suppose a particular system never terminates, we have to specify a particular confluent state because otherwise the notion of all is bad.