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market cap = book value + discounted future cash flows = share price * number of outstanding shares

When you do a buyback, the book value drops (company loses cash), but the discounted future cash flows remains unchanged. The number of outstanding shares also drops.

The net result is the stock price increases as a company accumulates cash and uses it for buybacks because the number of outstanding shares drops.

Another way of thinking about it is that it's the same as dividends, but the dividend only goes to the sellers of the stock during a buyback.

Re:OpenAI Five Benchmark on Wednesday July 18, 2018 @03:13PM (#17561253)
There's nothing about PPO that helps it learn long-range strategies. It primarily lets you make multiple steps for a single batch so you can converge faster.

In fact, for a single step with no policy lag, it's equivalent to a standard policy gradient update.

DeepMind was also able to train a CTF agent with human-level reaction time: https://deepmind.com/blog/capture-the-flag/

I suspect the difference that allows you to train with reaction time is an RNN or compensating for the lag some other way. I'm testing that out right now with my own SSBM bot: https://www.twitch.tv/vomjom

Re:OpenAI Five Benchmark on Wednesday July 18, 2018 @02:22PM (#17560830)
The author of that paper has since built an agent that has human-level reaction time and is comparable against professional players: http://youtube.com/vladfi1
Re:Swift for TensorFlow on Friday March 30, 2018 @06:52PM (#16720480)
People rarely train ML models on macOS for the reason you mentioned. Most machine learning work happens on Linux, so this should work well there.

TensorFlow supports a standalone server mode where it receives computation graphs and executes them. This is nice because then you can remotely execute on any accelerator (Cloud TPU, multi-worker multi-GPU) from your laptop.

In their demo, they did exactly that with a Cloud TPU: it connected to a TensorFlow server that executed the machine learning training part of the program.

Re:Swift for TensorFlow on Friday March 30, 2018 @06:25PM (#16720331)
Re:Cloud TPUs in Beta on Monday February 12, 2018 @10:00AM (#16358966)
Keep in mind that what you linked refers to TPUv1, which is built for quantized 8-bit inference. The TPUv2, which was announced in this blog post, is for general purpose training and uses 32-bit weights, activations, and gradients.

It will have very different performance characteristics.

Re:Google TPU Performance Analysis on Wednesday August 23, 2017 @10:39PM (#15087207)
An exponent bit flip, especially at later layers, would completely break inference.
Re:TensorFlow 1.0 Released on Wednesday February 15, 2017 @05:08PM (#13655808)
Yeah, essentially a lot of supporting libraries were written in Python at first, and they need to be ported to C++ to make other languages train.
Re:TensorFlow 1.0 Released on Wednesday February 15, 2017 @01:13PM (#13654036)
I'll discuss this a bit during my talk at the dev summit.

The short answer is no.

The long answer is yes, but only if you create the model in Python, export it, and then feed training data in other languages. There are some people doing exactly that.

Long term, I'd like to give all languages equal footing, but there's quite a bit of work left.

(I agree that thread-per-request works just fine in the majority of cases, but it's still worthwhile to write about the cases where it doesn't work.)

Responding to your original post: you argue that async/await intends to solve the problem of data races. That's not why people use it, nor does it tackle that problem at all (you still need locks around shared data).

It only tries to solve the issue of highly-concurrent servers, where requests are bound by some resource that a request-handling threads have to wait for the result of (typically I/O).

Coroutines/fibers are not an alternative to async servers, because they need primitives that are either baked into the language or the OS itself to work well.

It's not clear what you're suggesting as an alternative. My understanding is that you're suggesting thread-per-request, which has many known flaws. There are three approaches to serving requests:

1. Thread-per-request. This is a simple model. You have a fixed-size thread pool of size N, and once you hit that limit, you can't serve anymore requests. Thread-per-request has several sources of overhead, which is why people recommend against it: thread limits, per-thread stack memory usage, and context switching.

2. Coroutine style handling with cooperative scheduling at synchronization points (locks, I/O). This is how Go handles requests.

3. Asynchronous request handling. You still have a fixed-size thread pool handling requests, but you no longer limit the number of simultaneous requests with the size of that thread pool. There are several different styles of async request handling: callbacks, async/await, and futures.

#2 and #3 are more common these days because they don't suffer from the many drawbacks of the thread-per-request model, although both suffer from some understandability issues.

I think this is fair. Bandwidth costs money, usage likely follows a power law distribution, and their fees are reasonable:

AT&T: $10/50 GB = 20 cents/GB

Amazon S3/EC2: 10 cents/GB

It's not like we're being gouged here...

Re:Borders file for bankruptcy on Thursday February 17, 2011 @04:07AM (#2230353)
That would never happen.

The problem is that Amazon has no operations in certain states to avoid charging sales tax. Buying Borders would put them in every state.

Re:Google Sawzall now open source on Wednesday November 03, 2010 @04:18PM (#1866317)
Re:The Stock Market Is Still for Suckers on Saturday August 21, 2010 @02:34PM (#1623352)
At least in economic theory, a company does not give out dividends if it believes that it can get a better return on its cash (in terms of profit) than the investor can in the overall market.

But, companies must eventually give out dividends. There's a certain point at which the company's cash hoard gets so large that investors become unhappy (see Microsoft).

Re:Is a Crash Coming? Reasons to Be Cautious on Sunday August 15, 2010 @04:48PM (#1605896)
The article doesn't make it very clear, but Shiller's number is based on the average inflation-adjusted earnings of the previous 10 years.

See the Excel file here: http://www.econ.yale.edu/~shiller/data.htm

The stock market is still very highly priced compared to historical standards (excluding the past 15 or so years).

See also the graphs on: http://en.wikipedia.org/wiki/Robert_Shiller

Re:Testing an idea - need a specific data set on Saturday May 08, 2010 @12:40AM (#1329621)
It's possible to extract the address ranges, street names, city, and state using the TIGER/Line dataset. It won't give precise addresses (for example, if the range is 200-300 and address 250 doesn't exist, it won't say that). It also isn't that easy to deal with.

http://www.census.gov/geo/www/tiger/

I'll link to your TrueSkill post for those who haven't read it (it's excellent): http://www.moserware.com/2010/03/computing-your-skill.html

Although I already knew and understood TrueSkill before your post, it helped solidify my understanding. I hope you write more articles like that in the future :)

Re:Are 80% of Harvard Students First Borns? on Saturday March 06, 2010 @12:53PM (#1171839)
There are many obvious problems with this argument:

1. The 80% number seems to be pulled out of the air. It could be a counting error or a statistical aberration of that class, and the real Harvard number could revert to the mean.

2. The type of parents who could send a child to Harvard is a biased sample of the general population. It will mostly tend towards rich, white (or asian) families, who generally will have less children.

There's definitely not enough information to infer that first-borns are any different.

Re:Size Matters: $30,000 Per Inch on Wednesday February 17, 2010 @07:41PM (#1133075)
Well, I mentioned this study to a friend, and he made a good point:

The metric in the study is how many messages women send to men. If you're a taller woman, you likely will not message men who are shorter than you.

So, if you're taller, you have a bigger pool of women who would end up messaging you, which may account for much of the difference.

Re:SVMs : Beginner's resources on Tuesday February 09, 2010 @12:24AM (#1111615)
If you don't care too much about the theory and just want to get up and running, you should read:

http://www.csie.ntu.edu.tw/~cjlin/papers/guide/guide.pdf

And libsvm is probably the most widely used svm library:

http://www.csie.ntu.edu.tw/~cjlin/libsvm/

The author of the above paper and library is the same one giving the lecture in the OP's third link.

Re:Choosing a vector difference function on Thursday February 04, 2010 @06:51AM (#1100311)
There are far better methods than the one linked in the article.

You can train a covariance matrix such that you can get a better distance metric. Particularly, you would use the Mahalanobis Distance:

http://en.wikipedia.org/wiki/Mahalanobis_distance

For classification tasks, there are two good ways of training a covariance matrix for distance metrics: neighborhood components analysis and large margin nearest neighbors.

The effect in the article is just a particular quirk of using the euclidean distance. You could, for example, get the same result by using a 1-norm distance.

Re:Fish Oil may prevent severe mental illness on Monday February 01, 2010 @09:40PM (#1094118)
Almost all of the fish oil you can buy actually comes from 1 company and have been tested for mercury (by ConsumerLab.com and Consumer Reports):

http://www.usatoday.com/news/health/2004-12-15-fish-oil-usat...

None of the major brands had significant amounts of mercury.

I'd just get the cheapest kind, given that it's likely from the same company.

Re:Fish Oil may prevent severe mental illness on Monday February 01, 2010 @09:33PM (#1094110)
If you have a statistics background, it's pretty easy to tell that it's significant given the numbers (2 of 41 in the fish oil group and 11 of 40 in the placebo).

The exact p-value is in the paper (0.007), or very significant. It's often difficult to get those kind of p-values in real world settings:

http://archpsyc.ama-assn.org/cgi/content/abstract/67/2/146?l...

Re:Book Copies Y Combinator Logo For Cover? on Monday February 01, 2010 @12:10AM (#1091840)
A white Y using a standard font on an orange background isn't a hugely original logo.

It's quite conceivable that they came up with it themselves given the topic of the book.

Re:Cassandra 0.5 released on Sunday January 24, 2010 @09:20AM (#1073306)
I'd like to promote my python library for Cassandra:

http://github.com/vomjom/pycassa

Re:Study: Hybrid cars hit more pedestrians on Saturday November 28, 2009 @02:48AM (#964932)
There's also the possibility that hybrid drivers simply drive more often because their cost per mile is cheaper.
Re:What if we taught young children abstract algebra first? on Saturday November 14, 2009 @08:38PM (#942461)
It's almost always better to teach the concrete and practical before the abstract.

That's like teaching the rules of grammar before teaching them to read and write.

Re:How I Became a Keynesian on Tuesday October 20, 2009 @12:32AM (#891771)
That's not completely true.

Spending increases the velocity of money ( http://en.wikipedia.org/wiki/Velocity_of_money ) which can, in the short term, increase employment.

Re:Ask HN: Virtual PBX for startup? on Tuesday October 20, 2009 @12:14AM (#891748)
Please elaborate on why RingCentral should be avoided. I've never had any serious problems, although I'm wondering if I'm missing something.

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