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Why âLearnâ?
īŽ Machinelearning is programming computers to
optimize a performance criterion using example
data or past experience.
īŽ There is no need to âlearnâ to calculate payroll
īŽ Learning is used when:
ī¨ Human expertise does not exist (navigating on Mars),
ī¨ Humans are unable to explain their expertise (speech
recognition)
ī¨ Solution changes in time (routing on a computer network)
ī¨ Solution needs to be adapted to particular cases (user
biometrics)
3.
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What We TalkAbout When We
Talk AboutâLearningâ
īŽ Learning general models from a data of particular
examples
īŽ Data is cheap and abundant (data warehouses, data
marts); knowledge is expensive and scarce.
īŽ Example in retail: Customer transactions to
consumer behavior:
People who bought âDa Vinci Codeâ also bought âThe Five
People You Meet in Heavenâ (www.amazon.com)
īŽ Build a model that is a good and useful
approximation to the data.
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Data Mining/KDD
īŽ Retail:Market basket analysis, Customer relationship
management (CRM)
īŽ Finance: Credit scoring, fraud detection
īŽ Manufacturing: Optimization, troubleshooting
īŽ Medicine: Medical diagnosis
īŽ Telecommunications: Quality of service optimization
īŽ Bioinformatics: Motifs, alignment
īŽ Web mining: Search engines
īŽ ...
Definition := âKDD is the non-trivial process of
identifying valid, novel, potentially useful, and
ultimately understandable patterns in dataâ (Fayyad)
Applications:
5.
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What is MachineLearning?
īŽ Machine Learning
ī¨ Study of algorithms that
ī¨ improve their performance
ī¨ at some task
ī¨ with experience
īŽ Optimize a performance criterion using example data or
past experience.
īŽ Role of Statistics: Inference from a sample
īŽ Role of Computer science: Efficient algorithms to
ī¨ Solve the optimization problem
ī¨ Representing and evaluating the model for inference
6.
Growth of MachineLearning
īŽ Machine learning is preferred approach to
ī¨ Speech recognition, Natural language processing
ī¨ Computer vision
ī¨ Medical outcomes analysis
ī¨ Robot control
ī¨ Computational biology
īŽ This trend is accelerating
ī¨ Improved machine learning algorithms
ī¨ Improved data capture, networking, faster computers
ī¨ Software too complex to write by hand
ī¨ New sensors / IO devices
ī¨ Demand for self-customization to user, environment
ī¨ It turns out to be difficult to extract knowledge from human expertsī failure
of expert systems in the 1980âs.
Alpydin & Ch. Eick: ML Topic1
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Learning Associations
īŽ Basketanalysis:
P (Y | X ) probability that somebody who buys X also
buys Y where X and Y are products/services.
Example: P ( chips | beer ) = 0.7
Market-Basket transactions
TID Items
1 Bread, Milk
2 Bread, Diaper, Beer, Eggs
3 Milk, Diaper, Beer, Coke
4 Bread, Milk, Diaper, Beer
5 Bread, Milk, Diaper, Coke
9.
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Classification
īŽ Example: Credit
scoring
īŽDifferentiating
between low-risk
and high-risk
customers from
their income and
savings
Discriminant: IF income > θ1 AND savings > θ2
THEN low-risk ELSE high-risk
Model
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Classification: Applications
īŽ AkaPattern recognition
īŽ Face recognition: Pose, lighting, occlusion (glasses,
beard), make-up, hair style
īŽ Character recognition: Different handwriting styles.
īŽ Speech recognition: Temporal dependency.
ī¨ Use of a dictionary or the syntax of the language.
ī¨ Sensor fusion: Combine multiple modalities; eg, visual (lip
image) and acoustic for speech
īŽ Medical diagnosis: From symptoms to illnesses
īŽ Web Advertizing: Predict if a user clicks on an ad on
the Internet.
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Supervised Learning: Uses
īŽPrediction of future cases: Use the rule to predict
the output for future inputs
īŽ Knowledge extraction: The rule is easy to
understand
īŽ Compression: The rule is simpler than the data it
explains
īŽ Outlier detection: Exceptions that are not covered
by the rule, e.g., fraud
Example: decision trees tools that create rules
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Unsupervised Learning
īŽ Learningâwhat normally happensâ
īŽ No output
īŽ Clustering: Grouping similar instances
īŽ Other applications: Summarization, Association
Analysis
īŽ Example applications
ī¨ Customer segmentation in CRM
ī¨ Image compression: Color quantization
ī¨ Bioinformatics: Learning motifs
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Reinforcement Learning
īŽ Topics:
ī¨Policies: what actions should an agent take in a particular
situation
ī¨ Utility estimation: how good is a state (ī used by policy)
īŽ No supervised output but delayed reward
īŽ Credit assignment problem (what was responsible for the
outcome)
īŽ Applications:
ī¨ Game playing
ī¨ Robot in a maze
ī¨ Multiple agents, partial observability, ...
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Resources: Journals
īŽ Journalof Machine Learning Research
www.jmlr.org
īŽ Machine Learning
īŽ IEEE Transactions on Neural Networks
īŽ IEEE Transactions on Pattern Analysis and Machine
Intelligence
īŽ Annals of Statistics
īŽ Journal of the American Statistical Association
īŽ ...
19.
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Resources: Conferences
īŽ InternationalConference on Machine Learning (ICML)
īŽ European Conference on Machine Learning (ECML)
īŽ Neural Information Processing Systems (NIPS)
īŽ Computational Learning
īŽ International Joint Conference on Artificial Intelligence (IJCAI)
īŽ ACM SIGKDD Conference on Knowledge Discovery and Data Mining
(KDD)
īŽ IEEE Int. Conf. on Data Mining (ICDM)
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Summary COSC 6342
īŽIntroductory course that covers a wide range of machine
learning techniquesâfrom basic to state-of-the-art.
īŽ More theoretical/statistics oriented, compared to other
courses I teachī might need continuous work not âto get
lostâ.
īŽ You will learn about the methods you heard about: Naïve
Bayesâ, belief networks, regression, nearest-neighbor (kNN), decision
trees, support vector machines, learning ensembles, over-fitting,
regularization, dimensionality reduction & PCA, error bounds,
parameter estimation, mixture models, comparing models, density
estimation, clustering centering on K-means, EM, and DBSCAN, active
and reinforcement learning.
īŽ Covers algorithms, theory and applications
īŽ Itâs going to be fun and hard work
Alpydin & Ch. Eick: ML Topic1
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21.
Which Topics DeserveMore Coverage
âif we had more time?
īŽ Graphical Models/Belief Networks (just ran out of time)
īŽ More on Adaptive Systems
īŽ Learning Theory
īŽ More on Clustering and Association Analysisī covered
by Data Mining Course
īŽ More on Feature Selection, Feature Creation
īŽ More on Prediction
īŽ Possibly: More depth coverage of optimization
techniques, neural networks, hidden Markov models,
how to conduct a machine learning experiment,
comparing machine learning algorithms,âĻ
Alpydin & Ch. Eick: ML Topic1
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