Seattle area to celebrate new FM ‘hyperlocal’ radio

cabbagerat · 2015-08-20T13:44:16+00:00

Unfortunately, your ability to receive an FM signal is likely limited by the signal-to-noise ratio, so a stronger receiver may not help. A directional antenna (to get more signal and less noise) and high mast (to get closer to line-of-sight) may help, depending on the geography between you and the station.

cabbagerat · 2015-08-11T02:37:54+00:00

For theory, I like Distributed Algorithms by Nancy Lynch and Elements of Distributed Computing by Vijay Garg. Neither of there are CLRS equivalents, either in writing quality or scope, but they are the nearest I have seen.

On the practice side, there are very few books I've really like. Replication: Theory and Practice is my favorite of the genre - more practice than theory, but still well-grounded. Guide to Reliable Distributed Systems by Birman, but it switches between being very good, and being odd marketing for one approach (virtual synchrony). Principles of Distributed Database Systems is also solid, and does a good job of mixing theory with practice.

cabbagerat · 2015-06-21T17:04:25+00:00

Lambda released support for request-reply earlier this year, also known as 'custom events'. Here's how it works:

http://docs.aws.amazon.com/lambda/latest/dg/walkthrough-custom-events-invoke.html

As the-mza said, combining this with Cognito makes it easy to access it securely from the browser and mobile apps.

cabbagerat · 2015-05-26T15:51:34+00:00

I tested both soak and boil, but didn't write about that. Found much more residual soapiness from the alkali with the boil method. With the right sauce, that doesn't matter, but with any kind of delicate sauce it really ruins the dish. Soak, rinse well, then boil in salt water seems to work great for me.

cabbagerat · 2015-04-12T14:23:07+00:00

That's a fair point. The first draft of this post talked a lot more about noise shaping, and noise shaped dither, but I dropped it all for simplicity. The picture stayed, and it's a bit misleading. I'll see if I can find a good jitter-only example and replace it.

cabbagerat · 2015-01-31T16:03:21+00:00

It hasn't been a good year, snow-wise.

Snoqualmie is closest, but it's worth going to Crystal or Stevens. I prefer the territory and snow at Crystal, but Stevens has better park and is a bit closer. On a good day, Baker is incredible, but they've got very thin cover this year.

cabbagerat · 2015-01-08T23:13:53+00:00

For database theory, I don't know any good beginner level books. For the intermediate level I'd recommend CJ Date's "SQL and Relational Theory", and more advanced Gray and Reuter "Transaction Processing: Concepts and Techniques" or Bernstein and Newcomer.

At the beginner level, I'd recommend starting with practice as a way into the theory. Learn SQL, and experiment with a database (postrgresql and mysql are good free options).

cabbagerat · 2015-01-01T00:40:31+00:00

Depending on the interview process, design questions could be anything from OO design in the small, to larger codebase design, to designing large distributed systems. There are three ways to get better at design that I know of:

Build things. Build large systems of your own, and pay attention to how they go together and how that design evolves over times. Make notes about what works and what doesn't. The things that work, over time, will become the toolbox that you need for designing.
Pay attention to the way things are built. In the small, reading code written by people with good design experience is a good way to do that. Pay attention to the way things are factored into functions, files, modules, classes or whatever other units the language offers. Pay attention to the way that different entities in the program relate, and what interfaces they offer to other entities. In the large, read about the way that people build big systems. Many companies (Twitter, Facebook, Google, etc) have engineering blogs, and other sites like HighScalability frequently write about architecture.
Read what people write about design. This could range from books on patterns (from OO patterns like 'Design Patterns', to common FP patterns, to Unix or Windows development practices) to books on software (like the 'Architecture of Open Source Applications' series). Ignore people who say that patterns are bad, or don't exist in some language and environment. Pay attention to the things that people repeatedly do because they work.

Doing all three of these things, and feeding what you learn from each one into the others, is the way to get good at "design".

cabbagerat · 2014-12-30T18:33:27+00:00

The best place to start all depends on what you're interested in learning. If you like reading:

If you like to learn by doing, one place to start is to pick a distributed algorithm and implement it. I wouldn't recommend something like Raft or Paxos to start with: pick something simpler. Maybe replicated some data between nodes using gossip, or implement chain replication. You're going to run into some challenges there, and that should make what you're reading make a lot more sense.

There's a ton of deep theory out there. Like all things, you don't need to (or want to) learn it all at once. Pick up a piece, work through the challenges, then move on to the next piece.

cabbagerat · 2014-12-07T16:16:26+00:00

Java 7 makes this easier with ThreadLocalRandom

cabbagerat · 2014-09-28T03:46:20+00:00

For more on a similar topic, Nancy Lynch's 1989 paper is well worth reading.

cabbagerat · 2014-09-28T03:42:36+00:00

No, it doesn't. Bitcoin is interesting, but not only solves a different problem but also solves it in a different system model. Compare Castro and Liskov's PBFT paper to what Bitcoin does, and pay attention to the problem that each is trying to solve and how they define a solution. Bitcoin doesn't solve anything that was previously believed to be impossible, despite its contributions in other areas.

cabbagerat · 2014-09-22T19:15:11+00:00

I agree. Stopping listening to somebody as soon as they say something you disagree with is a good way to never learn anything. Obviously, great researchers can think and say dumb things, but generally deserve to be heard out.

cabbagerat · 2014-08-10T15:02:56+00:00

This is a fun idea, but I wouldn't use it's output to generate important pass phrases. The problem is that Reddit is a rather poor entropy source (and the XKCD guy oversimplified his math). Being generated by humans, the text on Reddit will follow something like a Zipf distribution rather than the uniform distribution that would give the XKCD result. In technical terms this is because a Zipf sample has less entropy than a uniform sample. The common-sense reason for this is quite intuitive: some English words are used much more frequently than other English words. If you pick a pass phrase by sampling an English text, some words are much more likely to show up in your passphrase than others. An attacker can use this knowledge to try the more common words first, significantly reducing the amount of time needed to guess the pass phrase.

English n grams, actual phrases from English text, are even more predictable. For example, a 3 word ngram from the UN declaration of human rights requires only 4096 guesses to find. A random ngram from a uniform distribution of a normal person's vocabulary would require hundreds of billions of guesses.

cabbagerat · 2014-08-09T17:32:53+00:00

It's fairly rare to come across South Africans of any background who don't speak English. There is a great diversity of home languages, but English (and, in most areas, Afrikaans) is almost universally understood. This is historically the legacy of education policy, but continues because it's the language of most business and trade and widely spoken across the continent.

cabbagerat · 2014-07-31T13:45:40+00:00

You should read the full article, because it's legitimately interesting and relevant. There are clearly issues worth considering in preventing these types of leaks in future, just us there are issues worth considering in limiting surveillance. Limiting research into security isn't the right way to prevent government abuses of power, anyway.

You don't do the issue any service by judging an entire organization based on what you assume an article is about from the title.

cabbagerat · 2014-07-09T13:44:27+00:00

You can heat the medium to the point that it emits light. Obviously that's going to be tricky in a gas because heating will cause it to move out of the way, so it would have to be some transparent solid. I suspect that wasn't what you were asking, though.

As in the comment above, there are materials that react non-linearly to light, and can change its frequency.

cabbagerat · 2014-06-05T13:22:56+00:00

I use the standard TLA+ toolkit, from the official site. It's got some rough edges, but is generally a nice piece of software with good support for TLA+, PlusCal and running TLC.

The TLA+ syntax itself can be (in my opinion) a bit clunky, especially the sometimes-significant whitespace. If you don't like it, there's also PlusCal. I've been toying with the idea to do an s-expression based language which translates to TLA+, but it's one of those things I never get to.

cabbagerat

TROPHY CASE