Geohashing

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Geohashing

• Pedro GutierrezTomasz KrolikowskiApril Randolph

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What is GeoHashing

• Every day, the algorithm generates a new set of
  coordinates for each 11 latitude/longitude
  zone (known as a graticule) in the world. The
  coordinates can be anywhere -- in the forest, in
  a city, on a mountain, or even in the middle of a
  lake! Everyone in a given region gets the same
  set of coordinates relative to their graticule

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Our Motivation

• The purpose of this was to get people to go out
  on an adventure and see their local environment
  and a mobile device is the ultimate tool to guide
  the brave participants.
• Offer additional features that the website cant
  facilitate.

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Current Algorithm
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Current Algorithm

• The algorithm takes the current date and DOW
  stock market opening, Mon.-Fri., and runs it
  through an MD5 cryptographic hash function
• Converts it two 16 digits rational hexadecimal
  numbers into rational decimal numbers
• The two base-10 decimal numbers are then
  appended to the users latitude and longitude
  locations to give the daily coordinates

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Explain the other Algorithms

• The other algorithm also takes the current
  algorithms implementation and takes into account
  the users choice to most likely meet with other
  community Geohashers.
• The graticule area is queried against the eight
  graticules within 1 latitude and 1 longitude
• The user then can select that graticules
  Geohashing location to have the most probability
  of meeting other people.

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kXCD
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Nearest
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Most Users
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Features

• Sticky location notes
• Location Safety information
• Location Sharing (with privacy settings like
  proximity)

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Location Sharing

• Only show users of our geohashing program
• Don't show my location until I'm x miles from the
  goal
• Might display a notification to other users that
  I am en route to the goal

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Why G1

• The G1 is distributed by T-mobile and is the
  first device to be backed by the Android platform
• In particular the G1 has the best features for
  the Geohashing application with the compass
  capability along with the Google maps navigation.
  Does not just have the maps and directions, has
  more GPS capabilities.

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Location Safety information

•  Use online crime statistics to generate a safety
  percentage value for the area that the user is in
  and is provided in the goal area Graticule
  selection of the users.
• Use safety information to route via safer
  locations.
• Crime Data can be obtained from 'Unified Crime
  Reports'

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Test Strategy

• The Geohashing community is an adventure
  community with mostly mathematicians and computer
  scientist
• Select candidates with access to the T-mobile G1
  with a test date to locally participate with our
  Geohashing mobile application
• Provide particular criteria to report back a with
  feedback
• Response time should be within 100 to 200ms for
  user threshold of perceived lag
• For calculations run in the background in a
  different level thread

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Addressing foreseeable Problems

• The device has one of the extended battery lives
  for a 3G device with the talk time is 5 hours and
  ten minutes while the average battery talk time
  is 4 hours.
• Give the information to users of extended battery
  recharge packs to bring with mobile device
• Large numbers of users are able to be handled by
  the servers and will optimize the Geohashing
• A preference setting of users to possible meet
  numbers estimations
• Cell Network speeds for mobile device
• Optimize the implementation settings, can be done
  in eclipse, to not assume fast bandwidth but to
  have emulator running with similar bandwidth speed

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Sticky location notes

• Allow location based messages that are triggered
  by other users when they are x miles from where
  you put them on the map.
• The messages could be an audio clip, photo,
  video, or written note.

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Main Menu

• Menu Button on the Device will inflate on Screen
  Menu

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Goal Destination

• User has the option to select a specific
  algorithm to determine the Goal Destination

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Profile

• The User could write a short description about
  themselves.
• If anonymous is selected the description will not
  be broadcasted.

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Privacy Settings

• User has the ability share their profile with
  other users.
• They can set a radius within the Goal
  Destination.
• Zero not shared.

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Displaying Other Users

• By pressing Other GHs it will toggle on or off
  any other participants.
• Pressing on a pin will display other users
  descriptions

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Security Data

• Displays the most serious crimes and the amount
  occurrences of the current location.

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Question.

• Any Questions?
• ? ? ?
• ?