MavEtJu's Distorted View of the World - 2012-08

City2Surf 2012
Seeing IR with digital cameras
Timing is everything

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City2Surf 2012

Posted on 2012-08-12 17:00:00
Tags: Sports

The yearly City2Surf event was on again. It is a 14 kilometer walk (or run as some people prefer). This is my historical sheet.

2000: I was in it, but the website doesn't have the name...
2001: 2:42:08, but that was without the correction from the start to the starting-line. 2:20:00 assumed :-)
2002: Cough cough sick :-(
2003: 2:32:39, 2:12:00 assumed.
2004: 2:19:30. But they still did not have electronic measuring. Strange.
2005: 3:36:43. I got a blue bib! I walked with Naomi and carried Dirkie in the sling (who was six months old). They were in the yellow bib group, so I had already a 10 minute penalty! 03:10:00 assumed.
2006: Cough cough sick.
2007: Not entered.
2008: 2:42:19. I had Dirkie in the stroller. 2:20:00 assumed
2009: 3:30:18. Dirkie walked half of it and sat the other half on my shoulders.
2010: 2:35:57. Hanorah in the stroller.
2011: 3:12:18. Dirkie is now six years and walks much faster.
2012: 3:05:18. A new personal best for Dirkie.


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Seeing IR with digital cameras

Posted on 2012-08-08 17:00:00
Tags: iPhone, Hardware

In the past I have always been able to see if a infra-red remote control works (or a IR laser :-) by holding a digital camera in front of it and see the flashing of the IR LED on the screen.

However, after having purchased a TVB-Gone (which doesn't seem to work here....), I found out that the camera on the iPhone 4 and iPhone 4S don't pick up the flashing of the IR LED. How annoying. The Samsung Galaxy does still show it.

However, this is only limited to the main camera on the iPhone 4S! The camera on the screen-side still shows the IR flashes on the screen.


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Timing is everything

Posted on 2012-08-07 08:00:00
Tags: Numbers, Hardware

L1 cache reference ............................. 0.5 ns
Branch mispredict .............................. 5 ns
L2 cache reference ............................. 7 ns
Mutex lock/unlock ............................. 25 ns
Main memory reference ........................ 100 ns
Compress 1K bytes with Zippy ............... 3,000 ns (3 us)
Send 2K bytes over 1 Gbps network ......... 20,000 ns (20 us)
SSD random read .......................... 150,000 ns (150 us)
Read 1 MB sequentially from memory ....... 250,000 ns (250 us)
Round trip within same datacenter ........ 500,000 ns (500 us)
Read 1 MB sequentially from SSD* ....... 1,000,000 ns (1 ms)
Disk seek ............................. 10,000,000 ns (10 ms)
Read 1 MB sequentially from disk ...... 20,000,000 ns (20 ms)
Send packet AU -> Netherlands -> AU .. 320,000,000 ns (320 ms)


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