Mr. Kumalo, who died on Oct. 21 in Johannesburg at 82, brought to his photography a reporter's keen eye for detail as well as determination and caginess: when the police cracked down on picture-taking, he posed with his camera on his head as though joking and yielding to the ban but secretly taking shots with a preset timer.
After the key establishment timer reaches its preset threshold value, a node will delete all the individual keys of its neighbors (e.g., and ), the random numbers (e.g., and ), the pseudorandom function and the initial key to improve security as well as to save storage space in the node.
This allows a monitor to operate on a preset timer (e.g., 1 min on 1 min off) and extends the battery life.
They also have up to 10 preset timers.
Oil production restarted automatically after an elapsed time also preset in the programmable timer; long enough for both gas and water to recede by capillarity.
The app comes with a handy timer and an alarm so users can preset when their nighttime sounds should fade away and when they should be woken the following morning.
You can also use the app to select presets for Internet radio stations and set a timer to shut down the power.
In fact, Mr. Cherry said, since the heating system in most multifamily buildings is controlled by a heat-timer -- which turns the system on and off for preset periods of time -- the most common strategy superintendents use to determine whether there is sufficient heat in the building is to keep the furnace running until no one complains.
A radio recorder powered by a timer (a Sony CFM-10, plus a Radio Shack 63-892; total, roughly $60) is preset by tuning in the station, then setting the timer for the start and end times of the desired program.
Mr. Cherry explained that unlike private homes -- which typically have thermostats that will turn on the heat when the temperature falls below a preset level -- most large residential buildings use what is known as a heat timer.
