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MachineLearning-Lecture09

Instructor (Andrew Ng): All right, good morning. Just one quick announcement, first things for all of your project proposals, I’ve read through all of them and they all look fine. There is one or two that I was trying to email back comments on that had slightly questionable aspects, but if you don’t hear by me from today you can safely assume that your project proposal is fine and you should just go ahead and start working on your proposals. You should just go ahead and start working on your project. Okay, there’s many exciting proposals sent in on Friday and so I think the proposal session at the end of the quarter will be an exciting event.

Okay. So welcome back. What I want to do today is start a new chapter in between now and then. In particular, I want to talk about learning theory. So in the previous, I guess eight lectures so far, you’ve learned about a lot of learning algorithms, and yes, you now I hope understand a little about some of the best and most powerful tools of machine learning in the [inaudible]. And all of you are now sort of well qualified to go into industry and though powerful learning algorithms apply, really the most powerful learning algorithms we know to all sorts of problems, and in fact, I hope you start to do that on your projects right away as well.

You might remember, I think it was in the very first lecture, that I made an analogy to if you’re trying to learn to be a carpenter, so if you imagine you’re going to carpentry school to learn to be a carpenter, then only a small part of what you need to do is to acquire a set of tools. If you learn to be a carpenter you don’t walk in and pick up a tool box and [inaudible], so when you need to cut a piece of wood do you use a rip saw, or a jig saw, or a keyhole saw whatever, is this really mastering the tools there’s also an essential part of becoming a good carpenter. And what I want to do in the next few lectures is actually give you a sense of the mastery of the machine learning tools all of you have. Okay?

And so in particular, in the next few lectures what I want to is to talk more deeply about the properties of different machine learning algorithms so that you can get a sense of when it’s most appropriate to use each one. And it turns out that one of the most common scenarios in machine learning is someday you’ll be doing research or [inaudible] a company. And you’ll apply one of the learning algorithms you learned about, you may apply logistic regression, or support vector machines, or Naïve Bayes or something, and for whatever bizarre reason, it won’t work as well as you were hoping, or it won’t quite do what you were hoping it to.

To me what really separates the people from – what really separates the people that really understand and really get machine learning, compared to people that maybe read the textbook and so they’ll work through the math, will be what you do next. Will be in your decisions of when you apply a support vector machine and it doesn’t quite do what you wanted, do you really understand enough about support vector machines to know what to do next and how to modify the algorithm? And to me that’s often what really separates the great people in machine learning versus the people that like read the text book and so they’ll [inaudible] the math, and so they’ll have just understood that. Okay? So what I want to do today – today’s lecture will mainly be on learning theory and we’ll start to talk about some of the theoretical results of machine learning. The next lecture, later this week, will be on algorithms for sort of [inaudible], or fixing some of the problems that the learning theory will point out to us and help us understand. And then two lectures from now, that lecture will be almost entirely focused on the practical advice for how to apply learning algorithms. Okay? So you have any questions about this before I start? Okay.

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Machine learning. OpenStax CNX. Oct 14, 2013 Download for free at http://cnx.org/content/col11500/1.4
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