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Sensors


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5 replies to this topic

#1 BMAD

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Posted 04 December 2013 - 02:18 AM

You have two 3-bit sensors, A and B, that measure the same thing, whatever it is -- temperature of the room, radioactivity levels, whatever. Both sensors are hooked up to the same CPU, which takes in the sensor readings. You know that the sensors are designed so that their readings can be off by at most one bit. We claim that if B knows that A has sent the CPU a 3-bit sequence, then B only needs to send 2 bits, and the CPU will be able to reconstruct B's 3-bit measurement, thereby conserving bandwidth. How is this so?


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#2 bonanova

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Posted 05 December 2013 - 09:28 AM

B knows A's 3-bit sequence was sent. Does B also know what it is?


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The greatest challenge to any thinker is stating the problem in a way that will allow a solution.
- Bertrand Russell

#3 BMAD

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Posted 05 December 2013 - 01:01 PM

Not necessary for B to know


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#4 harey

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Posted 05 December 2013 - 06:28 PM

Spoiler for a response


Sorry I cannot hide it. Maybe because of the font?

Edit: Definitely, I have a problem with the editor.

Edited by bonanova, 05 December 2013 - 11:26 PM.
Per request canged table font to courier

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#5 harey

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Posted 05 December 2013 - 06:42 PM

Correction:
B sends:
- if(measurement<4) measurement else 7-measurement.

P.S. It would not be bad if the table in my previous post magically appeared in a fixed font.

Edited by harey, 05 December 2013 - 06:44 PM.

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#6 harey

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Posted 16 December 2013 - 09:30 PM

Prayer to bona alma:

 

- correct the post 4 with the correction from the post 5

- delete in the post 4 remarks that are not necessary anymore

- delete the post 5

- delete this post

 

...and pray with me that bmad concedes it is the Best Answer ;)


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