Neural networks were started about 50 years ago. Their early abilities were exaggerated, casting doubts on the field as a whole There is a recent renewed interest in the field, however, because of new techniques and a better theoretical understanding of their capabilities.
Motivation for neural networks:
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Scientists are challenged to use machines more effectively for tasks currently solved by humans.
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Symbolic Rules don't reflect processes actually used by humans
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Traditional computing excels in many areas, but not in others.
Types of Applications
For machine learning:
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having a computer program itself from a set of examples, so you don't have to program yourself. This will be a strong focus of this course (because it's the most widely successful type of neural network application): neural networks that learn from a set of examples. Whenever you talk about ``training'' a neural network, you're talking about a machine learning setting.
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optimization: given a bunch of constraints and a cost function, how do you find an optimal solution? e.g. house room design. Can be learning- or non-learning based.
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Classification: grouping patterns into classes: i.e. handwritten characters into letters. Usually learning oriented.
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associative memory: recalling a memory based on a partial match.
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regression: function mapping
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For cognitive science:
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Modelling higher level reasoning:
language
problem solving
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Modelling lower level reasoning:
vision
audition speech recognition
speech generation
Neurobiology: Modelling models of how the brain works.
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neuron-level
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higher levels: vision, hearing, etc. Overlaps with cognitive guys.
Mathematics:
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Mathematicians also study neural networks in all of these areas, to determine the representational power of this kind of architecture. Nonparametric statistical analysis and regression.
For philosophy:
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Can human souls/behavior be explained in terms of symbols, or does it require something lower level, like a neurally based model?
Where are neural networks being used?
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Signal processing: suppress line noise, with adaptive echo canceling, blind source separation
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Control: e.g. backing up a truck: cab position, rear position, and match with the dock get converted to steering instructions.
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Siemens successfully uses neural networks for process automation in basic industries, e.g., in rolling mill control more than 100 neural networks do their job, 24 hours a day
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Robotics - navigation, vision recognition
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Pattern recognition, i.e. recognizing handwritten characters, e.g. the current version of Apple's Newton uses a neural net
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Medicine, i.e. storing medical records based on case information
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Speech production: reading text aloud (NETtalk)
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Speech recognition
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Vision: face recognition , edge detection, visual search engines
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Business,e.g.. rules for mortgage decisions are extracted from past decisions made by experienced evaluators, resulting in a network that has a high level of agreement with human experts.
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Financial Applications: time series analysis, stock market prediction
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Data Compression: speech signal, image, e.g. faces
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Game Playing: backgammon
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etc...