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Classification Tools & Artificial Neural Network
Vinaytosh Mishra B-Tech (ECE) ,IIT(BHU)
MBA,IMNU,Ahmedabad
PG Diploma in Statistics & Computing ,Institute of Science ,BHU
Specialization in Digital Marketing ,University of Illinois ,Urbana Champaign ,USA
Agenda
Introduction of Machine Learning Type of Machine Learning Type of Classification Tools
Naïve Bayesian Logistic Regression Artificial Neural Networks
Comparison of three networks Results Conclusions
A Few Quotes “A breakthrough in machine learning would be worth
ten Microsofts” (Bill Gates, Chairman, Microsoft) “Machine learning is the next Internet”
(Tony Tether, Director, DARPA) Machine learning is the hot new thing”
(John Hennessy, President, Stanford) “Web rankings today are mostly a matter of machine
learning” (Prabhakar Raghavan, Dir. Research, Yahoo)
“Machine learning is going to result in a real revolution” (Greg Papadopoulos, CTO, Sun)
So What Is Machine Learning?
Automating automation Getting computers to program
themselves Writing software is the bottleneck Let the data do the work instead!
Traditional Programming
Machine Learning
ComputerData
ProgramOutput
ComputerData
OutputProgram
Types of Learning Supervised (inductive) learning
Training data includes desired outputs Unsupervised learning
Training data does not include desired outputs Semi-supervised learning
Training data includes a few desired outputs Reinforcement learning
Rewards from sequence of actions
Inductive Learning
Given examples of a function (X, F(X))
Predict function F(X) for new examples X Discrete F(X): Classification Continuous F(X): Regression F(X) = Probability(X): Probability estimation
Decision Boundary
What is good decision boundary ?
Naïve Bayesian
The Naive Bayesian classifier is based on Bayes theorem with independence assumptions between predictors.
A Naive Bayesian model is easy to build, with no complicated iterative parameter estimation which makes it particularly useful for very large datasets.
Despite its simplicity, the Naive Bayesian classifier often does surprisingly well and is widely used because it often outperforms more sophisticated classification methods.
How it works?
If this value is greater than certain probability value the combination will be selected in that class.
Logistic Regression
In supervised learning logistic is a regression model where the dependent variable (DV) is categorical. Logistic regression is used widely in many fields, including the medical and social sciences
Many risk prediction models based on Logistic Regression, have been developed to predict whether a patient has a given disease like diabetes, coronary heart disease, based on observed characteristics of the patient like age, sex, body mass index, results of various blood tests and anthropometric tests.
How it works ?
Contd..
Neural Networks
Used for:
Classification Noise reduction Prediction
Great because: Able to learn Able to generalize
Neural Networks: Biological Basis
Feed-forward Neural Network
Perceptron:
Hidden layer
Neural Networks: Training
Presenting the network with sample data and modifying the weights to better approximate the desired function.
Supervised Learning Supply network with inputs and desired outputs Initially, the weights are randomly set Weights modified to reduce difference between
actual and desired outputs Back propagation
Backpropagation
Comparison of three methods..
Dataset Description No of Attributes No of Instances Pima Indians Diabetes Database of National Institute of Diabetes and Digestive and Kidney Diseases
8 768
S/N
Attribute Description
1 Number of times pregnant NPG 2 Plasma glucose concentration PGL3 Diastolic blood pressure (mm Hg) DIA4 Triceps skin fold thickness (mm) TSF5 2-Hour serum insulin INS6 Body mass index (kg/m2) BMI7 Diabetes pedigree function DPF8 Age (years) AGE9 Class CLASS
Name of Method Bayesian Naïve Logistic Regression ANN (8-6-2) Accuracy of Prediction 76.3% 78.3% 79.7%
Result & Conclusion
As the results suggest the Artificial Neural Network based prediction model are better than traditional models like Bayesian Naïve and Logistic Regression. We were not able to witness a great difference in reported accuracy, among the models discussed. But with increasing number of variables, we may observe ANN as distant winner
The advancement in data base management technologies has enabled us to practice evidence based medicine. The technologies like cloud computing and Hadoop has made it easy to manage and share the data. The advance classification tools are more accurate and can be applied on larger database to classify the disease more accurately.
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