1. A method for elimination of spam in a data stream according to information density, the method comprising:
receiving, by a computing device, a stream of messages;
directing, by the computing device, the stream into at least one buffer;
repeatedly compressing, by the computing device, data in the buffer using a lossless compression algorithm; and
identifying, by the computing device, at least one first message in the buffer as spam, by determining that the at least one first message has been compressed below a threshold level.
2. A method according to claim 1, wherein receiving further comprises receiving a stream of messages containing textual data.
3. A method according to claim 2, wherein compressing further comprises:
determining that a term in the buffer has been encountered previously;
mapping the term to a single character representation; and
replacing the term in the buffer with the single character representation.
4. A method according to claim 1, wherein determining that the at least one first message has been compressed below a threshold level further comprises determining that the ratio of the compressed size of the at least one first message to the uncompressed size of the at least one first message is smaller than a threshold number.
5. A method according to claim 1 further comprising deleting the at least one first message.
6. A method according to claim 1 further comprising storing the at least one first message in a spam folder.
7. A method according to claim 1 further comprising identifying an account from which the at least one first message originated.
8. A method according to claim 7 further comprising publishing the account to a user of the computing device.
9. A method according to claim 7 further comprising blocking the reception of future messages from the account.
10. A method according to claim 1 further comprising determining that at least one second message in the buffer is not spam
11. A method according to claim 10 wherein determining that the at least one second message is not spam further comprises:
maintaining in memory accessible to the computing device a datum representing a quantity of data received in the stream;
determining that the computing device has received a greater quantity of data in the stream than the quantity represented by the datum since receiving the at least one second message; and
determining that the at least one second message has not compressed below the threshold level.
12. A method according to claim 10 wherein determining that the at least one second message is not spam further comprises:
maintaining in memory accessible to the computing device a datum representing a number of compression cycles;
determining that the computing device has performed a greater number of compression cycles than the datum since receiving the at least one second message; and
determining that the at least one second message has not compressed below the threshold level.
13. A method according to claim 10 further comprising providing the at least one second message to a user of the computing device.
14. A system for elimination of spam in a data stream according to information density, the system comprising:
a computing device;
at least one receiver, executing on the computing device, and configured to receive a stream of messages and direct the stream into at least one buffer;
at least one compressor, executing on the computing device, and configured to repeatedly compress data in the buffer using a lossless compression algorithm; and
at least one classifier, executing on the computing device and configured to identify at least one message in the buffer as spam by determining that the at least one first message has been compressed below a threshold level.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
Having thus described the preferred embodiments, the invention is now claimed to be:
1. An accelerated weathering apparatus comprising:
a test chamber having a support member to support a specimen which is to be tested;
a lamp for producing light in the test chamber; and
a high instantaneous, low average current ballast for controlling operation of the lamp wherein the ballast generates current pulses, at least some of the current pulses having peak values of at least 100 amps, said current pulses having root mean square (rms) average values of less than of the peak value over a full signal.
2. The invention according to claim 1, wherein the ballast includes:
a front end, supplied by an external power source, which generates high DC voltage;
an arc capacitor connected to store energy developed from charging action of the front end and to selectively release the arc capacitor energy into the lamp as short, high current pulses;
a starting transformer that generates a voltage used to ionize gas in the lamp to strike an arc;
a switch connected between the arc capacitor and the lamp and used to control generation of the current pulses; and
an internal or external timer to control the switch and transformer for selectively generating and supplying of the current pulses to the lamp;
3. The invention according to claim 1, further including:
dimming circuitry designed to limit energy transfer from the capacitor into the lamp.
4. The accelerated weathering apparatus according to claim 1, wherein there is a duty cycle of 1:10 or less.
5. The accelerated weathering apparatus according to claim 1, wherein the voltage on the arc capacitor is 500 volts or more.
6. The accelerated weathering apparatus according to claim 1, wherein the current pulses are delivered to the lamp at a rate of at least 60 per second.
7. The accelerated weathering apparatus according to claim 1, wherein the lamp is a xenon.
8. The invention according to claim 1, wherein the xenon lamp is supplied with a pulse of less than 1 ms duration.
9. A method of operating a high instantaneous, low average current ballast which controls a xenon lamp, said method comprising:
generating a high DC voltage to charge a capacitor to a desired level;
connecting the charged capacitor to the xenon lamp through a switch;
firing a starting transformer which generates a voltage field at the xenon lamp, thereby ionizing gases in the xenon lamp;
forming a main current path including the charged capacitor, the switch, and the xenon lamp, said switch being disposed between and in series with the charged capacitor and the xenon lamp;
delivering current to the xenon lamp through the main current path; and
opening the switch such that the capacitor is again disconnected from the xenon lamp and charged up to the desired value.
10. The method of operating a high instantaneous, low average current ballast which controls a xenon lamp according to claim 9, wherein the current delivered to the xenon lamp are current pulses, at least some of the current pulses having peak values of at least 100 amps, said current pulses having a root mean square (rms) average value of less than of the peak value over a full signal.
11. The method of operating a high instantaneous, low average current ballast which controls a xenon lamp according to claim 10, wherein there is a duty cycle of 1:10 or less.
12. The invention according to claim 9, further including:
using dimming circuitry, limiting energy transfer from the capacitor into the lamp.
13. The method of operating a high instantaneous, low average current ballast which controls a xenon lamp according to claim 10, wherein the method further includes supplying the current pulses to the xenon lamp at a rate of at least 50 per second.
14. The method of operating a high instantaneous, low average current ballast which controls a xenon lamp according to claim 10, wherein the method further includes charging the capacitor to 500 volts or more.
15. An accelerated weathering apparatus comprising:
a specimen chamber configured to hold a specimen;
a xenon lamp;
a high-instantaneous, low-average current ballast configured to run the xenon lamp including,
a front end, that produces a high DC voltage,
an arc capacitor designed to store energy and release the energy into the xenon lamp as short, high current pulses,
a starting transformer which generates a high voltage which facilitates striking an arc in the xenon lamp,
a switch located between the arc capacitor and the xenon lamp, wherein when the switch is in an on state, a high current pulse is generated from the energy on the arc capacitor, and is delivered to the xenon lamp, and when the switch is in an off state, current flow is blocked thereby allowing a build-up of the arc capacitor energy, without leakage to the xenon lamp,
a dimmer configured to limit the energy being supplied from the arc capacitor, thereby controlling light output of the xenon lamp;
an irradiance sensor, which measures the amount of light in the specimen chamber; and
an irradiance controller, which receives signals from the irradiance sensor, and adjusts a dimmer in accordance with the received signals, in order to maintain a preselected output from the xenon lamp.
16. The invention according to claim 15, further including:
a timer configured to control operation of the starter transformer and the switch such that current pulses controlling operation of the xenon lamp are provided at a controlled frequency.
17. The invention according to claim 15, wherein the current pulse delivered to the xenon lamp is at least 100 amps.
18. The invention according to claim 16, wherein the current pulses over a full signal have a root mean square (rms) average value of less than of the at least 100 amps, where there is a duty cycle of 1:10 or less.
19. The invention according to claim 15, wherein the xenon lamp has a peak voltage of over 600 volts.
20. The invention according to claim 15, wherein the dimmer limits the energy being supplied to the arc capacitor, thereby controlling illuminance of the xenon lamp.
21. A current ballast which controls a xenon lamp, said ballast comprising:
a front end, supplied by an external power source, which generates high DC voltage;
an arc capacitor connected to store energy developed from charging action of the front end and to selectively release the arc capacitor energy in the lamp as current pulses, at least some of the current pulses having peak values of at least 100 amps, at a rate of at least 60 pulses per second, wherein the current pulses have root mean square (rms) average values of less than of the peak value over a full signal;
a starting transformer that generates a voltage used to ionize gas within the lamp to strike an arc;
a switch connected used to control generation of the current pulses; and
an internal or external timer to control the switch and transformer for selectively generating and supplying of the current pulses to the lamp.
22. The current ballast of claim 21, further comprising:
dimming circuitry designed to limit energy transfer from the capacitor into the lamp.