|
1 | | -According to \cite{russell2016artificial}, learning agents are those that |
2 | | -\emph{improve their performance on future tasks after making observations about |
3 | | -the world} \cite[p.693]{russell2016artificial}. Learning behavior is present in |
4 | | -many species most notably humans. To create a learning algorithm means that the |
5 | | -creator did not have to anticipate every potential variant of an environment |
6 | | -that the agent is confronted with while still creating an agent that can act |
7 | | -successfully in such environments. Cognitive Sciences define learning as the |
8 | | -change of state due to experiences as a necessary requirement and often limit |
9 | | -the recognition of learning to some observable behavior |
10 | | -\cite[p.96f.]{cognition1999}. This applies to all known species and the same |
11 | | -definition can easily be applied to a learning artificial agent. A learning |
12 | | -agent that doesn't change its behavior is not very helpful and an agent that |
| 1 | +According to \cite{russell2016artificial}, learning agents are those that \emph{improve their performance on future |
| 2 | +tasks after making observations about the world} \cite[p.693]{russell2016artificial}. Learning behavior is present in |
| 3 | +many species most notably humans. To create a learning algorithm means that the creator did not have to anticipate every |
| 4 | +potential variant of an environment that the agent is confronted with while still creating an agent that can act |
| 5 | +successfully in such environments. Cognitive Sciences define learning as the change of state due to experiences as a |
| 6 | +necessary requirement and often limit the recognition of learning to some observable behavior |
| 7 | +\cite[p.96f.]{cognition1999}. This applies to all known species and the same definition can easily be applied to a |
| 8 | +learning artificial agent. A learning agent that doesn't change its behavior is not very helpful and an agent that |
13 | 9 | doesn't change its state can hardly have learned something. |
14 | 10 |
|
15 | | -The \ac {AI} community has for many years employed a \emph{loss function} as a |
16 | | -measure of learning progress. Loss functions describe the difference between the |
17 | | -actual utility of the right actions versus the results of the agents learned |
18 | | -actions. The exact loss function might be a mean squared error function or an |
19 | | -absolute loss depending on the learning algorithm that is used. |
| 11 | +The \ac {AI} community has for many years employed a \emph{loss function} as a measure of learning progress. Loss |
| 12 | +functions describe the difference between the actual utility of the right actions versus the results of the agents |
| 13 | +learned actions. The exact loss function might be a mean squared error function or an absolute loss depending on the |
| 14 | +learning algorithm that is used. |
20 | 15 |
|
21 | | -Computational learning theory looks at many different problems of learning: How |
22 | | -to learn through a large number of examples, the effects of learning when the |
23 | | -agent already knows something, how to learn without examples, how to learn |
24 | | -through feedback from the environment and how to learn if the origin of the |
25 | | -feedback is not deterministic \cite[]{russell2016artificial}. In this work, two |
26 | | -of those problems are of special interest: The ability to learn from previously |
27 | | -labelled examples and the ability to learn through feedback from the |
28 | | -environment. The former is called \ac {SL} and the latter is mostly |
29 | | -referred to as \ac {RL}. |
| 16 | +Computational learning theory looks at many different problems of learning: How to learn through a large number of |
| 17 | +examples, the effects of learning when the agent already knows something, how to learn without examples, how to learn |
| 18 | +through feedback from the environment and how to learn if the origin of the feedback is not deterministic |
| 19 | +\cite[]{russell2016artificial}. In this work, two of those problems are of special interest: The ability to learn from |
| 20 | +previously labelled examples and the ability to learn through feedback from the environment. The former is called \acl |
| 21 | +{SL} and the latter is mostly referred to as \acl {RL}. To understand the difference, it is also important to |
| 22 | +understand algorithms that don't have access to labels for existing data, yet are still able to derive value from the |
| 23 | +information. These belong to the class of \acf {UL}. Although this class is not heavily relied upon in the |
| 24 | +implementation of the actual agent in the later practical implementation, it is crucial for many tasks in machine |
| 25 | +learning such as data exploration or anomality recognition. |
30 | 26 |
|
31 | | -The following sections will cover both mentioned forms of learning and |
32 | | -Section~\ref{sec:neural_networks} will introduce an architecture that can be |
33 | | -used as the learning function in these learning problems. Finally, |
| 27 | +The following sections will describe both \acl {SL} and \acl {UL} and Section~\ref{sec:neural_networks} will introduce |
| 28 | +an architecture that can be used as the learning function in these learning problems. Finally, |
34 | 29 | Section~\ref{sec:Backpropagation} will explain how exactly \ac {NN} learn. |
0 commit comments