hot topics in artificial intelligence corin anderson (corin@cs) tessa lau (tlau@cs) steve wolfman...
Post on 19-Jan-2016
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Hot Topics inArtificial Intelligence
Corin Anderson (corin@cs)
Tessa Lau (tlau@cs)
Steve Wolfman (wolf@cs)
Overview
• Applications• Planning• Machine Learning• Robots• Intelligent User Interfaces• The Web• Other stuff around here
Applications
• Games– Chess: brute force search– Backgammon: reinforcement learning– Bridge: HTN, Monte Carlo simulation– Crosswords: combination of many expert modules– Quake: situation-action rules
• Autonomous Spacecraft– Deep Space One: Modeling, SAT-like planning
Planning
• The last thing you remember: UCPOP– Least-commitment planning– Expressive, versatile, but slow
• Graphplan– “Mutex”
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More planning
• SATPLAN– Encode planning problem in Boolean Satisfiability
(proposition logic)– Solve logic problem with general-purpose algorithms
• UCPOP is back!– Apply Graphplan-like heuristics to UCPOP– It’s surprisingly fast!
Machine Learning
• Overfitting– Extensive search in hypothesis space causes
overfitting– Occam’s Razor is just one possible bias
• Scaling up to handle huge training sets– Make intermediate decisions with subsamples– Produce less accurate predictors with subsamples
and combine them into ensembles
ML: Ensembles
• Bagging– create k training sets by sampling real input set– Learn k predictors for the task, vote among them
• Boosting– Learn a predictor from weighted sample of real input– Change weights to emphasize misclassified points– Repeat– Vote resulting predictors according to accuracy
ML: Active Learning
• Traditionally:– “Teacher” provides fixed set of instances– Learner trains using all instances
• But this isn’t efficient– Instances may be redundant– Instances may be expensive to generate– Training time proportional to num. training instances
• Active learning– Learner queries for most-useful training instances
Robots
• Test environments– RoboCup flavors (small, medium, large, Aibo™)– Urban rescue
• Interesting issues– Localization: “R2D2, where are you?”– Autonomous map building– Cooperative robot teams
• Heterogeneous, homogeneous
Intelligent User Interfaces
• Programming by demonstration (PBD)– End-user programming for non-programmers– System learns program by watching user do task
• Bayesian networks– Graphical representation of variable dependence– Used for plan and goal recognition
• Mixed-initiative interfaces– AI does what AI is good at (fast brute force search)– Humans do what humans are good at (inspiration,
hunches, etc.)
AI and the Web
• A rich environment for applications– Information agents
• Collaborative filtering; sorting news; etc.
– Data mining– Text understanding
• An application on its own right– Web analysis (structure, usage)– Content personalization
AI at the UW (current and recent)
• Machine learning: VFDT– Very Fast Decision Tree– Learn a decision tree in “one pass” of data– Incremental computation for each datum is small– Application: large, streaming data sets
• Web logs• Cell phone calls• Credit card transactions
UW: Intelligent user interfaces
• SMARTedit – PBD system for text editing• SMARTpython – PBD system for learning
programs– Frame PBD as Machine Learning problem– Learn using very few training instances
• DIAManD – User interface for machine learning– General framework for learner/human interaction– When IUI meets active learning
UW: Web
• Adaptive web sites– Mine web logs for patterns of usage– Transform site to improve structure
• Index page synthesis
– Personalize content per visitor• Add, remove links• Highlight content• No irrevocable changes!• Emphasis towards wireless visitors
UW: Robotics
• Markov localization– Not really here, per se, but by Dieter Fox
• Sony AIBO RoboCup team (2001)• Just getting started…
Startups from UW/AI
• NetBot (Weld, Etzioni)– Internet shopping agent (Jango project)– Purchased by Excite
• Nimble.com (Weld, Halevy, et al.)– XML data management
• Ad Relevance (Weld)– Target web advertising
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