Factoring Algorithm puzzle

What is the minimal number, X, of yes/no questions needed to find the smallest integer (other than 1) divisor of an integer between 2 and 166 (inclusive)?

We are asking for the exact answer in two cases:

1. In the worst case, i.e., what is the smallest number X for which we can guarantee finding it in no more than X questions.
2. On average, i.e., assuming that the number was chosen in uniform distribution from 2 to 166 and we want to minimize the expected number of questions.

OK, let’s get started:

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A glimpse at Modern Racism in dating?

Some data from the United States:

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Cellular phone table

intel P55 LGA1156 chipset and DDR3 Memory

When I first bought an Intel P55 chipset based motherboard and a LGA1156 Core i7 Processor, I thought the safest thing to do would be purchasing Standard memory from a reputable company with JEDEC approved voltage and timings.

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IT window

Current and near-future IT to keep an eye out for.

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the Quantitative GRE has a Quantitative failure:

The quantitative exam lumps a large portion of test takers with a significant variation in ability into a single score.

The verbal does not have a similar flaw.

the results from everyone who is trying to get into a graduate program:

clearly there is a problem here where the most common score of all test-takers is the maximum.

let’s take a closer look at how this makes the GRE Quantitative even less useful for specific graduate programs:

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trading lawns for frogs

A study of amphibians found that in suburban ponds of CT, about 21% of frogs were deformed, like males growing eggs inside their testes. Probably the result of lawn care products…

Lawns are stupid: we destroy nature, what has been there far longer than Europeans on these lands, to try to grow a plant which will not survive without all sorts of chemicals, machinery and energy to protect it, to show others that we too adhere to the same cultural standard for "well-kept" land, at the sacrifice of nature and the environment.

I’ve said it before but these kind of ground keeping is an arms race of suburbia where we all lose.

Isn’t sustainable nature beautiful?
Who’s really impressed with a lawn of cut grass?

*>?

Javascript Performance in modern browsers *DOM results added

I use google chrome almost exclusively when doing the web, but I see many people using a wide variety of web browsers these days.

So I wanted to see how fast they are in the immensely popular javascript:

<–relative speed. (higher is better)—>

OS: windows 7 64-bit b7048
RAM: 4GB DDR2-800
CPU: intel 2-core 3Ghz Penryn w/6MB cache
HDD: Samsung F1 7200rpm
Chipset: intel G45

v8 is http://v8.googlecode.com/svn/data/benchmarks/v3/run.html

sunspider is http://www2.webkit.org/perf/sunspider-0.9/sunspider.html

dromaeo JS is http://dromaeo.com/?dromaeo

dromaeo DOM is http://dromaeo.com/?dom|jslib|cssquery

(ie and safari 3 were not able to complete the dromaeo DOM test suite w/default settings)

note:

the 64-bit firefox I tested is not official; http://www.mozilla-x86-64.com/

google chrome 2.0.269.0 is a dev/beta build.

opera, IE, chrome, firefox, k-meleon, safari are all 32-bit unless otherwise noted.

the (unsolved) Mystery of my freezer **update: Solved

step 1: fill ice tray with normal water from tap

step 2: put tray in freezer

step 3: let time pass

step 4: open freezer to see ice spears shooting up from ice tray

this has happened more than once.

does this make sense to anyone?

apparently someone figured it out:
http://www.its.caltech.edu/~atomic/snowcrystals/icespikes/icespikes.htm

palindrome Pangram Puzzle – a work in progress

Definitions:

A palindrome is a sequence of words like "lid off a daffodil" or "shallot ayatollahs" that uses the same letters reading backwards as forwards.

A pangram is a sequence of words that contains every letter of the alphabet (at least once).

Puzzle:

Find the shortest sequence of words that is both a pangram and a palindrome.

The sequence need not form a meaningful or grammatical sentence.

Use this dictionary: WORD.LST

from ITA Software

is this solvable with 1 man’s resources and timeframe?

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#word problem, but first: why I’m an idiot:

So I’ve been working on this little puzzle:

“If the integers from 1 to 999,999,999 are written as words, sorted alphabetically, and concatenated, what is the 51 billionth letter?” from ita software

I outlined the framework of an algorithmic solution months ago when I first saw it, and i solved it with maple, but never got to implement it using a ‘proper’ programming language.

This problem came to mind again recently as a fun excuse to get my hands dirty with a computer programming language called python.

I’ll start at the end, and say I was totally frustrated, because my seemingly perfect algorithm gave the wrong answer, in spite of passing all sorts of verification tests… I finally got to the point I was so convinced that unless I failed to spell the 27 numbers in my native language’s naming scheme, the problem’s hint must have been wrong…. >>>

so 40 is ‘forty’, not ‘fourty’.  and then everything worked perfectly…

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I’m listening to:

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The Aspirins For My Children

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Matters & Dunaway

a mirror is better than a brain for phantom pain.

so about 90% of amputees have a terribly strange and lingering sensation that the missing limb is stuck in an awkward and uncomfortable position.

“phantom pain” is what people these days call it.

Meds don’t seem to do much.

apparently doing a sort of exercise of trying to move the missing limb while using mental imagery to imagine it actually happening reduces the phantom pain significantly.

Using mirrors to show the in-tact limb where the missing one would be while the amputee “sees” it moving as he wishes apparently has even more dramatic results:

Tricking our brains is so easy, but i guess that is nothing new.

partical physics

Intel to the rescue?: mainstream SSDs

looks like intel is implying they have a drive cluster size an order of magnitude smaller than current mainstream MLC drives.

This (obviously?) yields much better random small write performance, and according to this info, Intel did it w/o sacrificing STR…

I stole the photos from this anandtech piece.

After my 2 previous SSD investigations, I can’t wait to get my hands on these.

medicine

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 the knife

i like:

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germlin

do i like this?

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tonite only

this didn’t come from a video game

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clap your hands and say yeah

a good foo fighters song?

I like it anyway:

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this came from a video game

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Storage, Raid, and intel’s ICHxR

If you look in the Internet, in various forums including storagereview, hardocp, and anandtech you will find hundreds of people talking about RAID.  I’d say almost all of them involve someone thinking about using some onboard raid solution that came with their computer, and a bunch of other more “experienced” forum members posting replies to the effect of: “don’t even bother with it, buy a “real” raid controller and go from there”.

Let’s take a deep look at storage, and while we are there we can stop and see if the if Intel’s ubiquitous ich9r is any good at raid.

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Sometimes I can’t stop listening to a song.

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This is the only Sonic Youth song I know/like.

RiDATA Ultra-S Plus 64GB SSD

Let’s take a look at how RiDATA’s $270 64GB SSD compares with OCZ’s Core SSD:

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How I figured out my OCZ Core 64GB SSD

a 275USD 64GB SATA2 Solid State Drive with Reads up to 120-143MB/sec and Writes up to 80-93MB/sec with a seek time less than .35ms? That’s what OCZ claims, and that is what got me interested, but I soon realized it wasn’t so straightforward.

Read into it:

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Fast Large File Transfers on Windows Shares? Jumbo Frames?

Sometimes you may want to move large amounts of data over a network. The natural and probably naive assumption is that if you have a Gigabit Ethernet network, the transfer will occur at 1Gb/sec.

Many things can prevent this from happening:

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Song of last night

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plus move

song of the day

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Anni Rossi

Facebook catches up to myspace globally

… but still has a way to go to capture the most valuable pageviews:

Personally, every time I log into facebook I kind of want to die.

ratatat’s LP3

ratatat’s new album comes out 7/7/2008.

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My all-encompassing review:

It is awesome.

media is applephoric

So the 3g iphone was revealed/announced exactly as expected, and the product specs/features/design is, well, exactly as expected.

A very predictable product launch.

engadget had 20 posts relating to apple’s new phone between june 9th 2008 at 10:14am and 1:43am on june 10th.

It is no wonder apple’s price to earning ratio is 38

Microsoft does something cool

WorldWide telescope:

intel’s nehalem CPU

a x86 CPU market refresher for the last 6 months:

* 45nm intel quad and dual core CPUs

* 65nm AMD quad and tri-core cpus with TLB-bug fixed

*2 new integrated chipsets for AMD cpus (the AMD 780g and the nvidia 8200), with great media playback capabilities

Intel is dominating the middle and high-end, while low-power (45W dual (4850e) and 65W quad (9100e)) AMD cpus paird with the new integrated chipsets are very attractive media-centric platforms.

Coming Soon:

Intel’s G45 chipset which finally brings excellent video playback, decent 3d performance, and official 16GB ddr2 support to intel CPUs.

new 45nm notebook CPUs from intel are coming imminently, lowering power and heat with small laptops. Also new notebook chipsets similar to the G45 are arriving, along with a new wireless card with wimax.

Coming not-so-soon:

Intel’s first CPU with an integrated memory controller: (no more talking to ram via a northbridge)

for those interested in performance, It’s exciting.  This true multi-core chip will run in a similar thermal envelope as the current penryns.

more on nehalem

you can be a wesley

I went to see this band last night… the show actually started on time, so I missed their short set.

but they sound like this:

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So refreshing, even in its 96kbps glory.

Sucks I missed em, but I’ll see em on saturday.

But I did catch an interesting band from Kansas City.

for anyone who does sudoku on the metro:

If you picked up a newspaper with sudoku which was all wet and smudged,

and all you could read was this:

Can you fill in any other blocks to match the solution of the described sudoku puzzle?

if so, which ones, with what numbers, and why?

<note: comments might contain spoilers>

marriage makes you worse?

the obvious and probably correct interpretation is that single men feel a benefit in competing, to proving themselves, while married ones do not.

Interesting that the better tennis players seem more likely to get married by this data…

regardless , i imagine the results would be orders of magnitude more significant if it was done on women.

via http://www.staff.ncl.ac.uk/daniel.nettle/tennis%20players.pdf

Is there really a housing boom?

most people and media outlets seem to present [this argument]

and it’s cirtainly not bogus, but I think not a really useful perspective…

.
.
.

yes the prices are going up:

but not in any way that matters:

answer= no, there is no real housing boom during the past 10 years.

premise for ww3?

around 13% of the air pollution in north america originated in asia:

via http://www.nasa.gov/topics/earth/features/pollution_measure.html

vaguely interesting, but not surprising

number of sexual partners seems highly correlated to creative activity:

via http://www.staff.ncl.ac.uk/daniel.nettle/nettle%20and%20clegg%20proceedings%20b.pdf

more interesting optical stuff

Close your left eye and, with your right, focus on the plus sign.

The big blob should disappear at some point, … if not try a different viewing distance from the screen…

for me 1 foot worked.

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interesting eye-brain stuff

the Center peice of each face of the cube is exactly the same color on the screen.

thanks Mike D.

via http://www.moillusions.com/2008/01/color-tile-illusion-new-aspect.html

It must be that our minds are trained to predict the real characteristics of the objects, absolute color values are irrelevant… if two objects are in reality the same color, they will only appear to have the same color spectrum and magnitude in the same lighting conditions…. here the lighting conditions seem to be very different… light vs shade…. of course in this photo theres no way to tell if the darker face is caused by shade or just darker colors….

so in most real-world situations this would be shade,,, and these two colors , identical in different lights, would be very different in the same lighting conditions… so in a way our brain is supersmart…

this embedded visual processing/intellegence is usually prudent, but still interesting to isolate…

thieves like us

I think i like this song/band, but its getting hard to tell what i like, rather than what amuses me… its like the difference between laughing at someone or with ‘em (or myself) is becomming blurry…

regardless: 2thumbs^

¿i need a new laptop? update:added lenovo x300

i had high expectations for apples new ultra-portable laptop, considering apple seems to be one of the few companies that puts the extra effort into designing their PCs.

and here it is, the macbook air:

it seems everyone thinks its a new gift from god, after the iphone…

but lets actually take a step back and notice there are non-apple products out there…

issues with the air:

uses old 65nm cpu… what about penryn?

ram is almost free, yet its impossible to upgrade the air to 4GB

only 1 usb, no gigabit ethernet, no sd-card slot…

1.8″ IDE hard disk, so not possible to install a 7200rpm drive.

thin and light, sure… but a big footprint footprint, could have less unused space around the screen and keyboard.

A technically bigger laptop like the R500 will actually seem to be smaller in person since it’s more compact.

question: does it use UEFI 2.0 so one could install vista64SP1? other macbooks do not.

I think I’ll wait for penryn sff, and frankly the macbook air seemed large in person… thin yes, but has a large footprint, a 13.3″ display with a significant border around the screen.

I might go for another 12.1 like the toshiba R500, but again, I’ll wait for penryn.

mystery buggish thing

spotted by me and a friend a year ago:

photographed in the mountain forests here:

blind incest

bbc:

Twins in the UK seperated at birth Learn of their relation inadvertantly after marrying each other.

me:

One might think the same exact birthday, similar apperance and the fact they both were adopted might make them curious before he buys the ring.

optical.illusion.freaky.friday.fun

I have no idea why, but the dots non-adjacent to the one i’m looking at seem to blink black.

empty class

We have all seen graphs similar to this, but i think most of us tend to view our consumption as necessary, or at least useful.

Gasoline lawn mowers pollute roughly as much in an hour as a car does in 100 miles, not to mention all of the pollution and resources wasted in the machines themselves. (granted; lawn-mowing gas consumption is less than 1% of consumption by passenger vehicles in net)

environmentilists say to use push mowers.

I’m going to go one step further, the last step, and say why have a “lawn”?

Is nature such an eyesore?

Does the fact that you put effort and resources into your yard impress the neighbors?

Is someone who’s impressed with resources and efforts spent on your yard worth impressing?

Is it practical to specifically plant something and set up some sort of psuedo-ecosystem on your land that requires external maintanance?

Yes i realize people do this to get respect and essentially gain socio-economic class in the local scene, as is probably all consumption if you think about it enough.

But lawn upkeep is one of the class-climbing things that seems easy to cross off the list without any real loss, especially now days when playing the environmental card can bump you up more than what little a well kept lawn ever could.

puzzle.2b

draw 7 points on a plane

such that exactly 3 lines can be drawn which contain only 2 points.

Puzzle.2a

for all n larger than 5:

how can you arrange n points (not all in the same plane),

such that the plane of any 3 points contains at least four?

Puzzle.1b

Exactly how big is the smallest circle which can contain 3 non-overlapping coins with radii ‘r’ ?

solutions and/or hints may appear in the comments.

optical illusion of the day

freaky:

puzzle.1a

Exactly how big is the smallest (in area) triangle which can contain 3 non-overlapping coins with radii of ‘r’?

solutions and/or hints may appear in the comments.

test

if x>y:
    print("success")
if x<y:
        print("failure")