1. A system, comprising:
a plurality of devices disposed in a field, each respective device in the plurality of devices having a memory to store an identifier to uniquely identify the respective device among the plurality of devices, the respective device configured to selectively respond to radio frequency signals broadcast to the field based on the identifier stored in the memory and commands modulated on the radio frequency signals; and
a reader configured to transmit at least one first radio frequency signal to the plurality of devices to request a first device having a first identifier in the plurality of devices to response to a subsequent radio frequency signal and to request second devices having second identifiers different from the first identifier in the plurality of devices to generate no response to the subsequent radio frequency signal, the reader is further configured to transmit the subsequent radio frequency signal in response to which the first device having the first identifier is configured to provide at least one second radio frequency signal;
wherein the reader comprises a data processing system configured to determine a motion of the first device, based on a Doppler frequency shift detected in the at least one second radio frequency signal.
2. The system of claim 1, wherein the reader further comprises:
a first antenna configured to receive a first signal of the at least one second radio frequency signal at a first location; and
a second antenna configured to receive a second signal of the at least one second radio frequency signal at a second location;
wherein the reader is configured to determine a frequency difference between the first signal received at the first antenna and the second signal received at the second antenna and to determine the Doppler frequency shift from the frequency difference.
3. The system of claim 1, wherein the first device is configured to modulate data on the subsequent radio frequency signal.
4. The system of claim 3, wherein the reader is configured to normalize the at least one second radio frequency signal to detect the Doppler frequency shift.
5. A method, comprising:
transmitting at least one first radio frequency signal to a plurality of devices positioned in a field, wherein the at least one first radio frequency signal is configured to request a first device having a first identifier in the plurality of devices to response to a subsequent radio frequency signal and to request second devices having second identifiers different from the first identifier in the plurality of devices to generate no response to the subsequent radio frequency signal;
transmitting the subsequent radio frequency signal to the field;
receiving, from the first device having the first identifier, at least one second radio frequency signal that is responsive to the subsequent radio frequency signal;
determining a Doppler frequency shift in the at least one second radio frequency signal; and
identifying a motion of the first device, based on the Doppler frequency shift.
6. The method of claim 5, wherein the receiving of the at least one second radio frequency signal includes receiving a first signal using a first antenna and receiving a second signal using a second antenna; and the method further comprises:
determining a frequency difference between the first signal received via the first antenna and the second signal received at the second antenna;
wherein the Doppler frequency shift is determined based on the frequency difference.
7. The method of claim 6, wherein the motion of the first device is identified based on position, speed, acceleration or jerk.
8. The method of claim 6, wherein the at least one second radio frequency signal is actively transmitted from the first device.
9. The method of claim 6, wherein the at least one first radio frequency signal instructs the first device to increase backscatter of the subsequent radio frequency signal and the second devices to decrease backscatter of the subsequent radio frequency signal, for a duration of the transmission of the subsequent radio frequency signal.
10. The method of claim 5, wherein the receiving of the at least one second radio frequency signal includes receiving a first signal using a first antenna and receiving a second signal using a second antenna; and the first device is positioned between the first antenna and the second antenna.
11. The method of claim 10, wherein the first antenna and the second antenna are positioned on a line of motion of the first device.
12. The method of claim 5, further comprising:
detecting presence of the first device at a first location; and
determining presence of the first device at a second location based on the first location and the motion identified using the Doppler frequency shift.
13. The method of claim 12, further comprising:
determining a direction of the motion based on a strength of the at least one second radio frequency signal.
14. The method of claim 5, wherein the at least one second radio frequency signal is received from the first device in response to the subsequent radio frequency signal interrogating the first device.
15. The method of claim 14, wherein the receiving of the at least one second radio frequency signal from the first device comprises:
maintaining transmission of the subsequent radio frequency signal for a period of time.
16. The method of claim 15, further comprising:
removing data modulation from the at least one second radio frequency signal to determine the Doppler frequency shift.
17. The method of claim 16, wherein the data modulation is removed via normalization.
18. The method of claim 16, wherein the first device is configured to modulate data on the subsequent radio frequency signal.
19. A reader, comprising:
a signal generator configured to generate radio frequency signals to a plurality of devices positioned in a field;
at least one transceiver coupled with the signal generator to transmit at least one first radio frequency signal to the plurality of devices to request a first device having a first identifier in the plurality of devices to response to a subsequent radio frequency signal and to request second devices having second identifiers different from the first identifier in the plurality of devices to generate no response to the subsequent radio frequency signal;
a plurality of antennas configured to receive, from the first device that has the first identifier, a plurality of signals responsive to the subsequent radio frequency signal;
a processor coupled with the at least one transceiver to determine a motion of the first device, based on a Doppler frequency shift detected from the plurality of signals responsive to the subsequent radio frequency signal.
20. The reader of claim 19, wherein the processor is configured to determine a frequency difference between the plurality of signals responsive to the subsequent radio frequency signal.
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 pillar-shaped honeycomb structured body in which a large number of through holes are placed in parallel with one another in the length direction with a wall portion interposed therebetween, wherein
information of said honeycomb structured body is displayed on a circumferential surface andor an end face of the honeycomb structured body by using a two-dimensional code.
2. The honeycomb structured body according to claim 1, wherein
said two-dimensional code is a stack type two-dimensional code or a matrix type two-dimensional code.
3. The honeycomb structured body according to claim 1, wherein
said two-dimensional code is drawn directly on a honeycomb structured body by a laser marker or ink, or is displayed by an attachment of a seal or a label on which the two-dimensional code is displayed.
4. The honeycomb structured body according to claim 1, wherein
the angle between each edge of said two-dimensional code and the length direction of said honeycomb structured body is more than about 0 degree and less than about 90 degrees.
5. The honeycomb structured body according to claim 4, wherein
the angle between each edge of the two-dimensional code and the length direction of the honeycomb structured body is about 5 degrees to about 85 degrees.
6. The honeycomb structured body according to claim 1, wherein
said information is at least one kind of information regarding the end faces, information regarding the manufacturing history and dimension precision, and information regarding the weight.
7. The honeycomb structured body according to claim 6, wherein
said information further includes at least one kind of information selected from the group consisting of pressure drop, storage method, expiration date, disposal method, and points to remember, or information relating to URL of Internet displaying a catalogue.
8. The honeycomb structured body according to claim 1, wherein
said information is confirmed through a telecommunication line.
9. The honeycomb structured body according to claim 1, wherein
said honeycomb structured body is configured by combining a plurality of pillar-shaped porous ceramic members with one another through a sealing material layer, each pillar-shaped porous ceramic member having a large number of through holes that are placed in parallel with one another in the length direction with a partition wall interposed therebetween.
10. The honeycomb structured body according to claim 9, wherein
said two-dimensional code is displayed on the circumferential surface of the honeycomb structured body, and on the portion where the porous ceramic member resides under the sealing material layer comprising the circumferential surface.
11. The honeycomb structured body according to claim 9, wherein
said porous ceramic member comprises silicon carbide.
12. The honeycomb structured body according to claim 9, wherein
at least one of said end faces is subjected to a flattening treatment.
13. The honeycomb structured body according to claim 12, wherein
the flatness of said end face subjected to a flattening treatment is set to about 2 mm or less.
14. The honeycomb structured body according to claim 1, wherein
each of said through holes has one end which is sealed and the other end which is opened, and
all of or a part of said partition wall that separates said through holes with one another is configured to function as a filter for collecting particles.
15. The honeycomb structured body according to claim 14, wherein
a through hole having sealed ends on one face side and a through hole having sealed ends on the other face side are different from each other in opening diameter, or different from each other in aperture ratio at each end face.
16. The honeycomb structured body according to claim 1, wherein
said information regarding the end face, displayed on the circumferential surface of said honeycomb structured body, is displayed on a portion closer to either of the corresponding end face.
17. The honeycomb structured body according to claim 1, wherein
a catalyst for converting exhaust gases is applied to said porous ceramics.
18. The honeycomb structured body according to claim 1,
which satisfies the relation about 0.01\u2266(rR)\u2266about 0.75 when the curvature radius of the circumference of said honeycomb structured body is represented by R (mm), and the length in the circumferential direction of the honeycomb structured body of said two-dimensional code is represented by r (mm).