Week 11 UAS Flashcards
The difference between Temporal-Difference Learning and Adaptive Dynamic Programming?
- TDL is to match estimation utility value of state with follow state to reach and makes one matching the value of utility estimation of each transition state.
- ADP is to match estimation utility value of state with all sate to reach and makes some matching value needed for consistent between utility estimation value with environment modelling.
Approaches in Active Reinforcement Learning?
- Reflex agent: learn policy directly, function
mapping from states to actions - Q-learning: learns an action-value function, or Q function, giving the expected utility of taking a given action in a given state
- Utility-based agent: learn utility values for states, use it to select actions that maximize the expected outcome utility
The agent in Active Reinforcement Learning can get profit value from 2 method
- Greedy approach: maximize utility by using estimation model
- Wacky approach: random for all environment
What is Direct Utility Estimation?
Using least mean squares concept (reward to go) which use Bellman Equations
What is Active reinforcement Learning?
learn about optimizing mapping from states and actions
What is Temporal Difference Learning?
update utility value appropriately which is affected by final state
What is Natural Language Processing?
The Agent which want to add the information needs to understand (at least partially) of the human language which is sometimes ambiguous and unclear.
3 ways to find information based on information retrieval perspective in NLP?
- Text classification
- information retrieval
- information extraction
N-gram character models
N-gram character models is defined as a Markov chain of order that in a Markov chain the probability of character depends only on the immediately preceding characters, not on any other characters.
Smoothing approach N-gram models?
Linear Interpolation smoothing (backoff model) combines unigram, bigram, and trigram using linear interpolation.
Text classification also known as?
Categorization: given a text of some kind, decide which of a predefined set of classes it belongs to. Language identification and genre classification are examples of text classification, as is sentiment analysis (classifying a movie or product review as positive or negative) and spam detection (classifying an email message as spam or not-spam).
can be done with Naive bayes.
What is Information retrieval?
Information retrieval (searching information like Google) is the task of finding documents that are relevant to a user’s need for information. The best-known examples of information retrieval systems are search engines on the World Wide Web.
characteristics:
1. A collection of writings (document).
The system must determine which one want to be considered as a document (paper). Example: a paragraph, a page, etc.
2. User Query
The query is a formula used to find the information needed by the user.
In its simplest form, a query is a keyword and documents that contain the keywords are the searched documents.
3. Set of Results
The results from the queries. A part of the documents
in which is relevant to the query.
4. Display of result sets
Can be a list of results in a ranking of the title documents.
previously works with boolean models
What is Information extraction?
Information extraction is the process of acquiring knowledge by skimming a text and looking for occurrences of a particular class of object and for relationships among objects. The simplest type of information extraction system is an attribute-based extraction system TEMPLATE REGULAR EXPRESSION that assumes that the entire text refers to a single object and the task is to extract attributes of that object.
4 approximation for Information Extraction?
– Deterministic to stochastic
– Domain-spesific to general
– Hand-crafted to learned
– Small-scale to large-scale
Relational-based extraction system?
FASTUS.
divided to be 5 stages:
1. Tokenization: divide the characters into a token
2. Complex-word handling: handle words that contains grammatical rules
3. Basic-group handling: sort by morphological of the words
4. Complex-phrase handling: merge basic group to be an arrangement of words
5. Structure merging: combining structure that have been resulted