bhiv.com » General

Tongue Twisters in SQL

Brent — Wed, 28 Mar 2007 16:38:47 +0000

I was playing round the other night can came up with this SQL to solve a popular tongue twister:

SELECT

COUNT(woodpile.is_chucked)

FROM

woodpile,

woodchuck

WHERE

woodchuck.can_chuck = 1

AND

woodpile.is_chucked = 1

Here is another one:

SELECT COUNT(pepper.picked) FROM pepper WHERE pepper.picked_by = ‘Peter Piper’

A couple more with the tongue twisters:

Which wristwatches are Swiss wristwatches?

SELECT watch.* FROM watch WHERE watch.make = ‘Swiss’

Which witch wished which wicked wish?

SELECT witch.name FROM witch WHERE witch.wish_type = ‘wicked’ AND witch.type = ‘wicked’

Who washed Washington’s white woolen underwear
when Washington’s washer woman went west?

SELECT

washer.name

FROM

washer

WHERE

washer.gender = ‘female’

AND

washer.went != ‘west’

AND

washer.washed = ‘underwear’

AND

washer.fabric = ‘wool’

AND

washer.washed_for = ‘Washington’

Do too many posts overwhelm readers?

Brent — Tue, 27 Feb 2007 17:42:20 +0000

Problogger asks: What makes you unsubscribe from a blog’s RSS feed?

There is some interesting insight in the comments. I have tried to compile a summary of the comments so far. (I’ve stared my peeves)
17 – Too many posts
12 – Topics not focused or changes topics too often
10 – Not enough posts
10 – Not full text feeds (*)
9 – Repeated stories or unoriginal (*)
6 – Reader not interested
6 – Too long of stories or bad post layout
4 – Negative stories or attitude
4 – Too much self promotion
4 – Low quality of posts
3 – Story keep reappearing (usually frequent editing) (*)

I find it funny that not enough and too many posts were in the top three answers.

Time-management software — offline version

Brent — Mon, 15 May 2006 15:49:47 +0000

“Bill Westerman has joined the back-to-paper movement. Here are a couple of Bill’s ingenous methods for managing his time and to-do lists in his notebook.

Bill prefers the Miquelrius notebook (shown here).

Roll over the photo to see how it works.” (via Communication Nation)

SurvivaBall

Brent — Fri, 12 May 2006 20:20:20 +0000

Introducing SurvivaBall from Haliburton?

“For those of us who typically find corporate America’s response to global warming painfully flaccid, economically self-destructive, and morally reprehensible, Halliburton’s most recent contribution to climate change preparedness comes like a puff of fresh air.” – from Treehugger.

Even better is the instruction card:

Pretty funny joke.

Cook with lava

Brent — Thu, 12 Jan 2006 22:36:34 +0000

Because an oven or range just won’t get you that 2000° F boost you need. Dolphin Bay Hotel instructs the brave and curious How to Cook with Lava

theBuzz #001: Because I’m Lazy and Haven’t Created the Plugin I want

Brent — Thu, 05 Jan 2006 21:41:44 +0000

If you have noticed the “theBuzz” (bhiv = beehive.. bees.. they buzz, get it?) side bar and thought? Well, that seems a total waste of space, it is because I have been planning to roll my own WordPress plugin / Del.icio.us system. Mainly to emulate waxy.org because I think the idea of short and easy links is a great way around creating a full blown posts.

In the meantime, I will be consolidating all my links into a single entry, like so:

Data Mining Amazon Wishlists – A great read of what a programmer can do with public accessible information. Does make you wonder what people behind the curtains can do with full access to data
10 Beautiful Experiments, they say the most beautiful, but isn’t that in the eye of the beholder?
MySQL compatibility in PostgreSQL, in its beta stages but it is an interesting idea to say the least.
Creative tries and rewrites the definition of Podcast, sorry your products didn’t take over the world like Apple’s did, but this is a battle you can’t win.

Anyway, I think you may get the idea of what theBuzz will be like, nothing special just a simple quick links. The next issue will be shorter without all this explanation.

Upgraded to WordPress 2.0

Brent — Wed, 04 Jan 2006 00:11:15 +0000

The upgrade was pretty painless. I did back up everything, which was a good thing after I dropped the drop directory into my FTP client and didn’t want to go and pick out each file. But other than that I only seem to have one error on the admin page. Not sure who’s fault that is, but I’ll track it down in the next couple days.

Why this is a big deal for me, is I have been waiting for 2.0 to start with a couple plugins that I have been thinking about and now I can start to finish this site.

Isn’t it the fourth wall?

Brent — Wed, 04 Jan 2006 00:05:51 +0000

I’ve really enjoyed the last couple Dilbert comics where Scott Adams starts drawing himself into the comic. But I could have sworn it was the fourth wall that is broken, not the third. Or, is this some cleaver reference to it being a comic strip?

Defeating Digg’s CAPTCHA

Brent — Thu, 29 Sep 2005 20:19:04 +0000

While using digg.com, I was surprised to see such an obviously weak CAPTCHA challenge. I was able to create a script that defeats it with a 88% accuracy within a couple hours using nothing but free software. (If you are looking for code, forget it. This is almost too much information)

Digg’s CAPTCHA Weaknesses:

Dictionary Words
Same background
Same Font
No deformations
All lowercase letters
Constant colors

Tools

gocr – a GPL Optical Character Recognition program
ImageMagick – for command time image editing
Perl – to tie everything together

Sample Size
100 images with 95 different words with an average word length of 5.3 letters.

First Test
Just dumping all the images through gocr yielded 26% correct responses. Not too shabby. It yields some easily manipulated results:

= groUDS
= single
= t’ o.l,i.c,e ‘. . .’.’. ”,
= be.cause.

Looking at the results I’m sure that we could improve the results with a little string manipulation.

Tweaking output
We can mess with the output to yield better results

Convert all output to lowercase
Remove non letter characters
Spell checker

The first two yield 53% correct responses; just with this simple tweak we are able to get more correct guesses than incorrect. With adding the first guess of a spell checker it bumps the accuracy to 67%

Tweaking input

Removing boarder
Adjusting contrast and brightness
Using edge detection

So becomes

Since we are already over 2/3rds accurate we don’t need to adjust the input of every image, just the results that aren’t dictionary words. Part of them problem is that while one adjustment will improve results for one image, it will degrade the results for another. My solution was to try 10 variations, run them through the OCR and then spell check. I then had the program pick the solution with duplicate results, in the case of a tie or no duplicate I had the program pick the one with the fewest number of variations. This method resulted in the final accuracy of 88%.

Problems with this technique
While these quick results have come close to becoming usable, they are still a far cry from 100% accuracy. Since digg uses a consistent font I could train gocr for problematic letters (such as p) also given that in 100 images I received 5 sets of duplicate words I would estimate their dictionary is only a couple thousand and could hand tweak the results.

Other resouces

PWNtcha – a project to build a captcha decoder
Breaking a Visual CAPTCHA – the breaking of EZ-Gimpy CAPTCHAs

Disclaimer
I did contact digg last week to let them know I would be publishing this and offered them the opportunity to have it delayed while the upgraded their CAPTCHA. I haven’t heard from them as of now. I still offer them the opportunity to contact me and I will temporarily remove this article.

Update:
~30 hours after I posted this they have changed the nature of their CAPTCHA, I will be writting a follow up soon … here is my reponse