逻辑回归？

Artificial Neural Networks (ANNs) are a family of statistical learning devices or algorithms used in regression, and binary or multiclass classification, implemented in hardware or software inspired by their biological counterparts. The artificial neurons of one or more layers receive one or more inputs (representing dendrites), and after being weighted, sum them to produce an output (representing a neuron's axon). The sum is passed through a nonlinear function known as an activation function or transfer function. The transfer functions usually have a sigmoid shape, but they may also take the form of other non-linear functions, piecewise linear functions, or step functions. The weights of the inputs of each layer are tuned to minimize a cost or loss function, which is a task in mathematical optimization and machine learning.

A sigmoid function is a mathematical function that produces a sigmoid curve — a curve having an "S" shape. Often, sigmoid function refers to the special case of the logistic function shown at right and defined by the formula: P(t) = 1 / (1 + e ** （-t))

The logistic function or logistic curve models the S-curve of growth of some set P. The initial stage of growth is approximately exponential; then, as competition arises, the growth slows, and at maturity, growth stops.

A logistic function or logistic curve is a common sigmoid function, given its name in 1844 or 1845 by Pierre François Verhulst who studied it in relation to population growth. "Verhulst writes "We will give the name logistic [logistique] to the curve" (1845 p.8). Though he does not explain this choice, there is a connection with the logarithmic basis of the function. Logarithm was coined by John Napier (1550-1617) from Greek logos (ratio, proportion, reckoning [计算、估计]) and arithmos (number). Logistic comes from the Greek logistikos (computational). In the 1700's, logarithmic and logistic were synonymous. Since computation is needed to predict the supplies an army requires, logistics has come to be also used for the movement and supply of troops. So it appears the other meaning of "logistics" comes from the same logic as Verhulst terminology, but is independent (?). Verhulst paper is accessible; the definition is on page 8 (page 21 in the volume), and the picture is after the article (page 54 in the volume). "

[牛津和朗文]

  • logistic - relating to the logistics of doing something
  • logistics  - organization of supplies and services, etc for any complex operation 后勤

我觉得logarithim翻译成“对数”不错，请看分贝，比率/比例都需要一对数嘛。

posted @ 2022-12-20 13:16  Fun_with_Words  阅读(15)  评论(0)  编辑  收藏  举报

 张牌。