1. A lithographic projection apparatus comprising:
an illumination system to provide a beam of radiation;
an article support to support an article having at least one edge to be placed in a beam path of said beam of radiation; and
a clamp to clamp said article to said article support,
wherein said clamp is provided with a plurality of zones located substantially continuously around a circumference of said article support to create a locally adjusted pressure so as to provide a local bending moment near the edge of said article to locally bend said article.
2. A lithographic projection apparatus according to claim 1, wherein said article support comprises at least three support pillars.
3. A lithographic apparatus according to claim 2, wherein said article support consists of three pillars.
4. A lithographic apparatus according to claim 2, wherein said article support consists of four support pillars.
5. A lithographic apparatus according to claim 2, wherein said support pillars are actuable.
6. A lithographic apparatus according to claim 5, wherein said support pillars are piezo-pads.
7. A lithographic apparatus according to claim 1, wherein at least one of said plurality of zones comprises an individually controllable clamp.
8. A lithographic apparatus according to claim 7, wherein said clamp comprises a height sensor to sense a local height of the article.
9. A lithographic apparatus according to claim 1, further comprising a clamp control unit to adjust the clamping pressure of said plurality of zones to attain a leveled article.
10. A lithographic apparatus according to claim 9, wherein said clamp control unit is configured to control said clamping pressure in response to at least one of a detected local height of said article and a detected image quality.
11. A lithographic apparatus according to claim 1, wherein said plurality of zones comprise sectioned pressure zones to create a relatively differing backfill gas pressure.
12. A lithographic apparatus according to claim 1, wherein said article comprises a reticle.
13. An article support to support a flat article having at least one edge to be placed in a beam path of radiation, said article support comprising:
a clamp to clamp said article to said article support,
wherein said clamp is provided with a plurality of zones located substantially continuously around a circumference of said article support to create a locally adjusted pressure so as to provide a local bending moment near the edge of said article to locally bend said article.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of scaling communication messages in a network of data processing systems, each one of the data processing systems capable of transmitting alert messages to any other one of the data processing systems, the method comprising:
transmitting an alert message, which requests a reply, from a source one of the data processing systems to a plurality of recipient ones of the data processing systems, the alert message being received by the plurality of recipient ones of the data processing systems;
outputting the alert message by only a first subset of the plurality of recipient ones of the data processing systems, the first subset being fewer than all of the plurality of recipient ones of the data processing systems;
receiving, by the source one of the data processing systems, reply messages transmitted from at least some of the first subset of the plurality of recipient ones of the data processing systems in response to a receipt of the alert message;
determining, by the source one of the data processing systems, if a predetermined number of reply messages has been received from the at least some of the first subset of the plurality of recipient ones of the data processing systems;
in response to determining that the predetermined number of reply messages has not been received, retransmitting the alert message to the plurality of recipient ones of the data processing systems, the retransmitted alert message being received by the plurality of recipient ones of the data processing systems;
outputting the retransmitted alert message by a second subset of the plurality of recipient ones of the data processing systems;
assigning a probability to the alert message; and
determining, by each of the plurality of recipient ones of the data processing systems, whether to output the alert message based on the probability assigned to the alert message.
2. The method of claim 1, further comprising:
assigning a second probability to the retransmission of the alert message; and
determining, by each of the plurality of recipient ones of the data processing systems, whether to output the retransmission of the alert message based on the second probability assigned to the retransmission of the alert message.
3. The method of claim 1, wherein the alert message is one of an instant message and an electronic mail message.
4. The method of claim 1, wherein the alert message is one of a PollCast and a SkillTap message.
5. The method of claim 1, further comprising within each recipient device:
storing the alert message in a storage device;
determining if a predetermined amount of time has elapsed since a previous determination was made about whether to output the alert message;
determining whether to output the alert message based on output criteria; and
outputting the alert message if the output criteria is satisfied.
6. The method of claim 1, further comprising:
each of the plurality of recipient ones of the data processing systems determining whether to output the alert message by generating a randomized value and comparing the randomized value to the probability.
7. The method according to claim 1, further comprising the probability being determined using a random number generator.
8. The method according to claim 1, further comprising the probability being based on a total number of the plurality of recipient ones of the data processing systems.
9. The method according to claim 1, further comprising increasing the probability when the alert message is retransmitted.
10. A system for scaling communication messages in a network of communicating peer data processing systems, each one of the data processing systems capable of transmitting alert messages to any other of the data processing systems, comprising:
a source one of the data processing systems transmitting an alert message, which requests a reply, to a plurality of recipient ones of the data processing systems, the alert message being received by the plurality of recipient ones of the data processing systems;
only a first subset of the plurality of recipient ones of the data processing systems outputting the alert message, the first subset being fewer than all of the plurality of recipient ones of the data processing systems;
the source one of the data processing systems receiving reply messages transmitted from at least some of the first subset of the plurality of recipient ones of the data processing systems in response to a receipt of the alert message;
the source one of the data processing systems determining if a predetermined number of reply messages has been received from the at least some of the first subset of the plurality of recipient ones of the data processing systems;
in response to determining that the predetermined number of reply messages has not been received, the source one of the data processing systems retransmitting the alert message to the plurality of recipient ones of the data processing systems, the retransmitted alert message being received by the plurality of recipient ones of the data processing systems;
a second subset of the plurality of recipient ones of the data processing systems outputting the retransmitted alert message; and
wherein the source one of the data processing systems server assigns a probability to the alert message, and wherein each of the plurality of recipient ones of the data processing systems determines whether to output the alert message based on the probability assigned to the alert message.
11. The system of claim 10, wherein the source one of the data processing systems assigns a second probability to the retransmission of the alert message; and determines whether to output the retransmission of the alert message based on the second probability assigned to the retransmission of the alert message.
12. The system of claim 10, wherein the alert message is one of an instant message and an electronic mail message.
13. The system of claim 10, wherein the alert message is one of a PollCast and a SkillTap message.
14. The system of claim 10, wherein each recipient one of the data processing systems stores the alert message in a temporary storage, determines if a predetermined amount of time has elapsed since a previous determination was made about whether to output the alert message, determines whether to output the alert message based on output criteria, and outputs the alert message if the output criteria is satisfied.
15. A method of distributing messages to a plurality of client devices in a network, comprising:
receiving a message for broadcast to a plurality of client devices;
assigning a probability value to the message;
transmitting the message to the plurality of client devices;
at each client device, generating a randomized value;
comparing the randomized value of a client device to the probability value of the message; and
outputting the message based on the comparison of randomized value and the probability value.