Answer to Question 1
C
Answer to Question 2
There are two general types of location-based marketing techniques: geo-aware and proximity marketing. Geo-aware techniques identify the location of a user's device and then target marketing to the device, recommending actions within. Proximity marketing techniques identify a perimeter around a physical location, and then target ads to users within that perimeter, recommending actions possible within the fenced-in area. The perimeter can be from hundreds of feet (in urban areas) to several miles (in suburban locations). For instance, if users walk into the geo-fenced perimeter of a store, restaurant, or retail shop, they will receive ads from these businesses. Both of these techniques utilize the same locating technologies. GPS is the most accurate positioning method in theory, but in practice, the signal can be weak in urban areas, nonexistent inside buildings, signals can be deflected, and it can take a long time (30-60 seconds) for the device to acquire the signal and calculate a position. Wi-Fi location is used in conjunction with GPS signals to more accurately locate a user based on the known location of Wi-Fi transmitters, which are fairly ubiquitous in urban and suburban locations. Apple's iBeacon technology uses Bluetooth low energy (BLE), which uses less battery power than traditional Bluetooth or GPS and is more accurate than targeting through Wi-Fi triangulation.
Energy budget for a temperate deciduous forest (data from Gosz et al. 1978).
Nitrogen fluxes in Sycamore Creek, Arizona (data from Grimm 1988).
tree-ring data
Example of a patient’s ledger in practice management software.
data
Satellite data on primary productivity in the equatorial Pacific Ocean