skysight-inc/HackerNews huggingface dataset:
Freevolt's "RF Energy Harvesting Whitepaper" figure 1 shows the energy harvested from RF as .1µW/cm² to 2000µW/cm², but the text gives energy densities .01µW/cm² to 100µW/cm². This density estimate may be per transmitter(?) so the harvesting estimates only make sense if you assume multiple transmitters each contributing to the total harvested energy.

In Figure 3 they have a chart which shows ~30µW harvested from an unspecified, un-sized "Patch array 1x2" antenna".

Your optimistic estimate is 16µW/cm², so it is in the range of their power harvesting claims. (though I doubt their unspecified antenna is 100cm²)

What is feasible with an energy budget of 30µW? Well, using off the shelf microcontrollers and RF modules, you can send a packet every two minutes using the least optimistic estimates from http://jeelabs.org/2013/09/08/3-years-on-one-set-of-batterie... . The power consumption of the radio is the biggest element of the power budget, so you can add sensors without hurting your power budget too much. And probably you can do better than this with a better transmitter than the old RFM12B.

I don't think their claims are impossible for sensors that operate in the µW range of average power consumption, though though the top end estimate of 2mW/cm² in table 1 seems way too optimistic. But as you point out even a task as simple as blinking an LED a few times a minute is pushing it. You'll never power a mobile phone this way.

The whitepaper is http://www.getfreevolt.com/downloads/RF%20Energy%20Harvestin...
Not only that, but the London Underground already uses regenerative braking. Here's the press release from 2013 from when Alstrom got the contract to put in the system that is now being tested, http://www.alstom.com/press-centre/2013/5/alstom-to-supply-g... :

> Alstom was awarded a contract by UK Power Networks Services to supply its innovative Harmonic and Energy Saving Optimiser (HESOP) energy recovery system for the Victoria Line of the London Underground. ...

> London Underground already makes good use of regenerative braking but, by adding HESOP to the power supply arrangements, the residual energy that is currently wasted in braking resistors can be made use of – this will help prevent tunnel temperatures rising.
> I've never been offered a position by an Asian

so... this feels like discrimination, which is understandable.

> whereas I'm rarely not offered a position by a non-Asian.

... but does this feel like preferential treatment? because that's the logic you are presenting here.

"when i don't get hired, it's because of discrimination. when i do get hired, it's because i'm a good hire, not because someone else was discriminated against to hire me."

this is why these discussions are meaningless. there's no way of knowing why you did or didn't get hired. yet another reason to run your own company.
On some old systems, I remember that env vars of other UIDs could be seen, even if you weren't root. I wonder if that's still true for any systems out there.
ISTM the Transit's TC might just not be tuned very well? That might be related to the model year or might be something a Ford dealer could fix with a firmware update. Friends I've had in snowy places have sworn by their AWD vehicles. Personally I've scared myself half to death driving a big RWD truck in the snow.
Here’s how one New Yorker ditched his workaholic life for a two-day week
The idea of "spacetime" makes a fun narrative, fun thought experiments, and interesting ways to graph and visualize events.

But many physicists wish that popularizing this concept would stop and go away, because it is misleading. There is both evidence and theoretical work demonstrating that time, unlike the spatial dimensions, is not a choice when it comes to direction of travel, and never will be.

The definition of time as a numerical order of change in space is replacing the 106-year-old concept of time as a physical dimension in which change runs,” Sorli said. “We consider time being only a mathematical quantity of change that we measure with clocks. This is in accord with a Gödel view of time. By 1949, Gödel had produced a remarkable proof: 'In any universe described by the theory of relativity, time cannot exist.' Our research confirms Gödel's vision: time is not a physical dimension of space through which one could travel into the past or future.”

http://phys.org/news/2012-04-physicists-abolish-fourth-dimen...

Edit: previous thread on HN re this article: https://news.ycombinator.com/item?id=3842734

Sounds like some think this phys.org article is BS. I don't know, I am not a physicist. But I have been wondering for many years whether it makes sense to treat time as a dimension. I assumed it made sense in relativity study, and has been mistranslated in popular science culture as a thing that somehow opens up the option of time travel.
Rust Faster
> Me, I see the universe as information, and everything else flows from that.

I admire the Integrated Information Theory of consciousness (by Giulio Tononi) a lot. It provides an impressive intuition pump towards the nature of consciousness and the necessary conditions for it to arise. It also goes much deeper than "consciousness is a complex pattern in space-time", by detailing "what does it mean to be complex?", what kind of complexity leads to consciousness and how can we compare various systems to see their degree of consciousness/complexity.

The IIT surely does not give a definitive answer on consciousness, it is not even able to compute an approximate complexity score for the human brain, and doesn't explain why complexity is linked to consciousness in the first place, but it helps us see in many directions where we could only stumble in darkness before.
I have read (not sure) that Lee Kuan Yew wanted Singapore to become a British protectorate. In his calculation it was a waste to spend money on a military when it was in short supply.
OSM = OpenStreetMap.

Pages like this are why the convention developed of always defining your acronyms the first time they are used.
supporting anecdote: while jogging in Seattle, I got hit by a cop car turning right on red. only fell to the ground, no injuries (except bumper marks!), but I could imagine a heavy car like that not even registering a little kid hitting it at 5mph.
"reddit" is not a homogeneous community, it's a bunch of wildly different groups.
An EKG electrode needs to be Ag/AgCl to be reliable. Making your own is a good start to poor results.
C++ and Windows Internals and iOS (Swift)
I'd love to have the JVM equivalent of this for my company's main desktop product, written in Java. Due to being Java (and having an embedded JRE) the app has slow startup, due to the JVM having to be started up. The installer is 90 MB on OS X, 55 MB on Windows, much of which is the embedded JRE. So our our fortnightly updates are much bigger than they need to be.

We tried an AOT compiler called JET. It was fine, albeit expensive. But it has an extremely long build time, no great for our continuous build system. It's support Java version also lags considerably behind the current Oracle Java release.
https://en.wikipedia.org/wiki/Iore - mentioned in passing in an earlier thread at https://news.ycombinator.com/item?id=8732383 .
Heathrow's autonomous pod cars
The demographics and politics of gun owning households
The tube already does regenerative braking. This trial is about better regenerative braking. Currently, the trains return power to the track when braking, but if the track is already at capacity the remainder is dumped via resistors on-board the train. If I understand correctly, this new substation can sense when this is about to happen, take that extra current and feed it through an inverter to supply it back to the power grid.

Some more details are here: http://eandt.theiet.org/news/2015/sep/tube-brake-energy.cfm
I studied the line
read _ _ sid < <(2>&1 strace -esetsid setsid sh -c "exec $PROGRAM <> /dev/tty2 >&0 2>&1 ")

<( is an example of process substitution, in case anyone is interested. Basically it feeds the stdout of the subshell into the stdin of the read (previous) command.
Here is a detailed explanation:
http://www.tldp.org/LDP/abs/html/abs-guide.html#PROCESS-SUB
I am part of start up that is working in the recruitment space . We are also hiring node.js developers through our app. Is it ok to post here?
That's a rather pithy way to interpret what was said. Here's an alternate interpretation: be different from all the other applicants. If you have the same grades, the same extracurriculars, and the same things to talk about in an essay, you're not going to be different from everyone else and thus won't get in. And that's the nature of being different - you can't quantify it until you see it.

Having gone to a high-percentage Asian high school, I can tell you that traditional Asian parents mostly push their kids to do a limited set of things (high academic scores, orchestra, etc.), which can easily lead to a homogeneous pool of applicants.

Faust is saying that if you want your kid to get into Harvard, you should instead encourage them to do things that set them apart from the thousands of other smart kids applying. Build an airplane, climb a famous mountain, invent something, be a sailor, race sled dogs, etc. Those are the things that make an applicant stand out.
One reason that Asians outperform other racial groups in the United States is overlooked in the article: the difficulty of immigration. Most whites and blacks are born within the US, and Hispanics are either born or move into the US by simply crossing a land border. For Asians to come to the US, they have to cross the Pacific Ocean. In order to do that, they have to be either rich (at least middle class), highly educated, or extremely adventurous and self motivating. The Pacific Ocean filters out many would-be Asian Americans that would have lowered the average of the "modelness" of the group.
> There is a high barrier to research about pot and other drugs such as LSD, for obvious reason. This means that while you have a gigantic corpus of data about alcohol usage, for instance, you have next to nothing to work with on pot.

Prohibition prevents scientific research, but it is not true that there isn't a lot of indirect data. One of them is cause of death at emergency rooms. While alcohol produces a large number of deaths daily, cannabis produced zero so far (in the history of modern medicine).

> Just because you don't have studies showing pot is harmful it doesn't mean pot isn't harmful. Absence of evidence is not evidence of absence.

Sure, but this applies to everything. Maybe having brown curtains in your living room increases your chances of suffering from depression. Let's make brown curtains illegal until we know more?
I disagree. The very act of listening to someone with that level of pain, a level so great he was about to end his own life, and similarly listening to the pain of the other person with the same intensity, that's where the beauty lies.
I don't know, at this rate, in 9 days he'll need agreement from everyone in the world!
I'm basically saying that if one trait (appearance) can be different than other traits can be different as well.

In the abstract universe I'm referring to, imagine a bunch of balls and cubes. The balls have no sides and the cubes have six. We live in a culture that says this is the only difference between balls and cubes, otherwise balls and cubes are completely equal. This statement is not true, because balls can roll down a hill faster than cubes.

Outside of the world of mathematics words are used to refer to a fuzzy category of traits. If one trait in this category is different from another category then the possibility exists that another trait is also different, inductively speaking.
Free book of algorithms in Ruby
>absurd and racist suggestion that asian american applicants are on average much less "interesting" people

Talk about putting words in one's mouth...
Do I really want a piece of paper? Or a dashboard with the same contents - perhaps set as my browser's home page. With the addition of a few large format screens showing the dashboards in the work area, I think that would suit our group better than a printed piece of paper.

I think the more important concept is to get everyone in the group focused on the core metrics and one thing I do like about the idea is that there can be more than a "few key metrics".

I'm imagining every one of our application servers counting the errors that show up in the logs - right next to the raw hits and response time. We're responsible for more than 80 products and it would also be informative to show the error rates of products versus each other. Which of the products needs maintenance work most?

We capture metrics for some of the newer applications in Ganglia, but the idea that you might fit 500 numbers and spark-lines on a single dashboard has given me so great ideas.
Not really. The car is a FWD car. So when the rear wheels aren't being spun up, the car should produce ever so slightly more measurable power instead of less. Because, as you stated, it didn't have to spin up the rear wheels, etc.

The dyno can tell if both wheels are being driven or just the front ones. If it couldn't, then the results wouldn't be off by 10% but they'd be off by 50% as the dyno wouldn't understand that by having the two drums linked they got twice as heavy and it'd do the calculations based off of the inertia of a single drum instead of both drums.
>will dyno lower when driving the rear wheels as well as the front

well, it did BETTER on four wheels spinning, so how is that a bad test?
Not to put too fine a point on it, but 20% of those admitted were Asian American, for the class of 2019, in a country where less than 5%, self-identify as Asian-American.[1][2]

https://college.harvard.edu/admissions/admissions-statistics

[1]

http://www.theatlantic.com/education/archive/2014/06/how-to-...

[2]

http://www.theatlantic.com/education/archive/2014/06/how-to-...
>and still happens

No it doesn't. If anything, Jews now seem to benefit from a bizarre form of affirmative action, particularly at the institutions that once most discriminated against them:
http://www.theamericanconservative.com/articles/the-myth-of-...
1,000 words? It packs a lot into its brevity and it suits its medium.
Check out Avian (http://oss.readytalk.com/avian/). You can use it with the OpenJDK class library. You can even run your application plus the class library through ProGuard, then AOT-compile the whole thing to generate a boot image for fast startup.
There are laws making it illegal to collect data on open land
it's better than it used to be, and is improving.

a relative dearth of characters is worlds better than a population of deliberately hateful caricatures and racially venomous dialog.

i have white friends who started commenting maybe 10 years ago on how uncomfortable it was for them to watch that kind of shit on tv, because it wasn't just isolated incidents, it was basically a conspiracy to make asian people look absolutely fucking awful on tv/movies.

there was some outside pressure but i think society as a whole, including writers in hollywood, just started going "wtf are we doing here?" and is now moving toward neutral characters for asians actors i.e. nothing terrible, nothing amazing. there's an unremarkable asian family sitcom on tv, for example. i think a lot of the young writers probably grew up in a racially diverse group of friends.
No? Why? It isn't racist to say Africans have darker skin or different shaped faces to Caucasians, you know. It's a fact.
CloudSight seems fixated on what people are wearing. I tried multiple pictures of Shakira and CloudSight only seems to care what she is wearing.

https://dl.dropboxusercontent.com/u/3788882/SHAKIRA2.PNG
I don't think the US (or it's colonial forebears) forcibly occupying the land occupied by others, or importing others as enslaved laborers -- was _driven_ by racism either, especially at it's origin. It was driven by economic profit, same as usual. Europeans didn't conquer the Americas because they hated Native Americans, they did it because they wanted the land and it's resources. They didn't import slaves, originally, because they hated Africans, they did it because they wanted free labor.

But the pertinent thing about America is how the society was structured based on racism to _manage_ the economic exploitation. It was convenient to those on top to color-code the socio-economic structure. And this was done at an early stage in European settler colonial society in North America (By the 1600s it was fairly solidified).

This is what makes racism the 'original sin' of the U.S.

And it is definitely not at all a constant in historical examples of nations or kingdoms conquering land. There are plenty of examples, especially pre-modern, of the conquered people being fully or mostly integrated into the conquering society on the same basis as the already existing population of the conquererors. Now, especially in pre-modern times, 'the same basis' could mean as impoverished and disenfranchised peasants -- but the same as the impoverished and disenfranchised peasants of the conquering kingdom, state, or nation. Or in other cases, incorporated into an existing society that is somewhat more complex and with opportunities for advancement

(How the Ottoman Empire treated it's conquered populations is super interesting, and certainly not always great, but _very different_ from how we assume this thing works in modern times. The Ottoman Empire was sort of a pre-modern socio-political structure that hung on into the beginnings of modernism).

There has always been conquering in human history, and it's often been brutal. Even in the pre-Columbian Americas. (Although at the same time it's not been _universal_, there are more and less brutal, and more and less expansionist, societies in human history. )

But the very idea of 'race' is a modern phenomenon, as is structuring a stratified society based on race. (And the idea of race developed in the main during a process of structuring societies based on racial stratification, in a way that hadn't genererally existed before).
Use differential privacy to simulate having more modeling data
The number of memory safety problems in memory-safe languages is much, much lower than in non-memory safe ones

Citation?

I have actually analyzed this and memory-safety-related problems in Firefox are the majority of critical security vulnerabilities.

Cool. That means you can provide actual numbers and statistics... right?
Agreed. You are probably right about the outcome. It is easy to just add an interaction of nominal score group (high, med, low) vs. mismatch/match and see if there is an effect.

At our startup we get depersonalized credit data but we don't have a nice panel like the Fed :) so cannot really do that analysis on our end. I would be nice if they released this data publicly -- once it is setup for modeling (with just a few variables), it is so hard to re-identify so the risk of privacy invasion is low. I doubt that will happen though.
Docker image with Tor, Privoxy and a process manager under 15 MB
Internet stocks were trading at all-time highs in 1999. Housing was doing great in 2006. Any asset being at all-time highs doesn't mean there are negligible risks only that the majority of the market currently thinks there is (they might be right and they might be wrong).
I don't think I am missing the point. The Alto hardware was fairly simple, most stuff was done in software.

What do you want to build today that is too expensive to try out ?
Hi, htop author here: this brought a smile to my face! Wondering if I should do the same in htop's own website. Would be fun to follow the activity spike when the new major release comes later this year! Major kudos to the author for the idea!
If I had to guess, I would say it's the cultural imperative of the family unit.

One of the worst things slavery did, to african americans as a people, is to strip away their cultural meaning of family unit.

I think it's on-par with the holocaust in terms of the human cost. Yes, there are a lot of other things, but not having a stable family unit while growing up messes up the next generation, perpetuating the cycle. That is how black people are different from any other ethnic minority in the US. And that's why I think hispanic people(PC term?) will climb the economic ladder before/faster.
> I'm sure that @graycat will
scoff at those
recommendations, but his
reading list would be
considered excessively hardcore
and time consuming
even for a graduate student
in math, which I'm
assuming you're not.

Probability and stochastic
processes based on measure
theory are not very popular
in the US, even in graduate
math departments.

Uh, scoff, scoff. Okay?

The full measure theoretic details
of stochastic processes in
continuous time can be a bit
of a challenge. That topic can
be important, e.g., for Brownian
motion and stochastic differential
equations used in mathematical
finance. Of course, there is

Karatzas and Shreve,
Brownian Motion and Stochastic Calculus
and Chung and Williams,
Introduction to Stochastic Integration.
And there's much more, especially from
Russia and France.

But, otherwise, usually in practice,
what people are interested in is either
(1) second order stationary stochastic
processes, e.g., as in electronic or
acoustical signals and noise. There
are commonly interested in power spectral
estimation, digital filtering, maybe
Wiener filtering, the fast Fourier transform,
etc. or (2) what is in, say, Cinlar,
Introduction to Stochastic Processes.

In Cinlar,
for the continuous time case,
get a good introduction to
the Poisson process (the vanilla
arrival process, e.g.,
like clicks at a Geiger counter,
new sessions
at a Web site, and much more).
Also get
what else people are mostly interested
in in practice, Markov processes
in discrete time with a
discrete state space (that is, the
values are discrete).

The case of Markov processes in
continuous time and discrete state
space is not so tough if the
jumps are driven by just a Poisson
process. But there is still more
in Cinlar.

And there are other good texts on
stochastic processes.

For (1), look at some of the
texts used by EEs. The measure
theory approach is in
Doob, Stochastic Processes,
Loeve, Probability Theory,
and several more texts by quite
good authors.
E.g., without measure theory,
can just dive in via
Blackman and Tukey, The Measurement
of Power Spectra ....

With all these sources,
are able to get by without
measure theory.
Yes, without measure theory,
at some places will have to
not ask to understand too much
and just skip over some details
to get back to the applied stuff.

But for measure theory, the
Durrett text seems to get
a student to that unusually
quickly.

For more, at the MIT Web site,
there is an on-line course
in mathematical finance that
avoids measure theory.
They want to use the
Radon-Nikodym theorem
and Ito integration but
still avoid measure theory.
Uh, the Radon-Nikodym theorem
is a generalization of the
fundamental theorem of calculus.
Once see it, it's dirt simple,
but a good proof takes a bit
or follow von Neumann's proof
that knocks it all off in one
stroke (it's in
Rudin, Real and Complex Analysis).
It's great that you think this way. I see too much of this pressure with my friends who have kids. They want to see them do math and read before they're x years old, with x being one or two less than what the cheaper schools are doing. My 3.5 says more elaborate sentences than the older kids, but never showed any special interest in math, and I never felt that he was ready to learn to read. It's completely normal for a 3.5 kid to not be ready to learn these things.
Cowspiracy: the film that environmental organizations don't want you to see
I'm not the one to defend Harvard, but an unestablished minority group only has so many opportunities so of course a lot of peoples resumes are going to look the same. That said, this is pretty much just traditional elitism. If your work harder than anyone else you'll still not get recognized because you're not claimed to be smart, cultured, pretty or interesting enough.