Abstract:
Provided is a power control method for a mobile Radio Frequency Identification (RFID) reader and an RFID reader using the same. The RFID reader includes: an RFID reader transmission/reception control unit for creating a message to be transmitted to an RFID tag and transmitting RFID tag information to a terminal control unit; a reader transmitting unit for encoding and modulating the created message; a power amplifier for amplifying an output signal; a reader receiving unit for demodulating and decoding the signal and transmitting the signal to the RFID reader transmission/reception control unit; and an RFID reader power control unit for controlling power, wherein when the RFID reader transmission/reception control unit receives a command for acquiring the RFID tag information, the RFID reader power control unit applies power to the power amplifier.
Abstract:
Provided is a method for estimating the number of tags in a slotted Aloha-based RFID system, which can estimate the number of tags through a new statistical average scheme using the number of slots, the measured number of empty slots, and the measured number of ID slots. The estimating method includes the steps of: a) setting the number (N) of slots, the measured number (c0) of empty slots, and the measured number (c1) of ID slots as parameters; and estimating the number (n) of the tags by substituting the set values into n=(N−1)/(c0/c1).
Abstract:
Provided is a collimator device for radiotherapy including: a body including a first through unit and disposed on a path of high energy radiation which in use is irradiated toward a patient's treatment part; a frame including a through hole corresponding to the first through unit and slidably installed in the body; a plurality of multi-leaf collimators (MLCs) slidably installed in the through hole and including radiation shields; a servo motor coupled to the body and the frame in a power manner so as to slidingly move the frame with respect to the body; and a motor controller externally receiving position displacement data regarding a motion of the patient's treatment part due to a patient's breathing and generating a signal for controlling the driving of the servo motor so that the MLCs follow the patient's treatment part and continuously apply radiation to the patient's treatment part based on the position displacement data.
Abstract:
A method and apparatus to display a status of an optical recording and/or reproducing apparatus. The method includes, determining a type of an optical disc loaded into a tray; transmitting a predetermined signal based on the determination result to a laser emitting diode module comprising at least two laser emitting diodes, which emit different color beams so that the laser emitting diode module emits a color beam based on the determined type of the optical disc.
Abstract:
Provided is a method of exposing a wafer using a scan-type exposure apparatus. The method includes scan exposing a first shot selected from a first shot column formed of an array of shots disposed in a row in a first direction. The first shot column may be included in a plurality of shots repeatedly formed in the first direction and a second direction that are substantially orthogonal to each other in an exposure target area on the wafer. The method further includes scan exposing a second shot that is included in a second shot column and disposed in a diagonal direction to the first shot. The second shot column may be formed of an array of shots disposed in a row in the first direction and is closer to the first shot column than any other shot in the plurality of shots.
Abstract:
Provided is a method for securing information between a Radio Frequency Identification (RFID) reader and tag, and an RFID Reader and tag using the same. The method includes the steps of: a) requesting an access password of the RFID tag in the RFID reader; b) extracting a key value mapped to the access password transmitted from the RFID tag and transmitting the key value to the RFID tag in the RFID reader; c) outputting a hash function value from the key value transmitted from the RFID reader in the RFID tag; and d) determining whether to allow the RFID reader to access to an RFID tag memory based on whether the outputted hash function value is the same as the access password of the RFID tag.
Abstract:
A gain-clamped semiconductor optical amplifier includes a semiconductor optical amplifier for amplifying an inputted optical signal and outputting amplified spontaneous emission light, the amplified spontaneous emission light consisting of a first portion and a second portion, the first portion having a wavelength range to be amplified. The amplifier further includes a wavelength selective reflector for allowing the first portion of the amplified spontaneous emission light to pass through the wavelength selective reflector and reflecting the second portion of the amplified spontaneous emission light again to the semiconductor optical amplifier, thereby clamping the gain of the amplifier.
Abstract:
A semiconductor optical amplifier for amplifying input optical signals is disclosed. The optical amplifier includes a substrate; a first active layer laminated on the substrate for generating pumping lights; a second active layer laminated on the substrate being gain-clamped by the pumping light and amplifying the input optical signals; and a grating formed on an upper portion of the substrate, adjacent to a boundary between the first active layer and the second active layer, for partially allowing the transmission of the pumping lights to the second active layer and partially reflecting the pumping lights.
Abstract:
Disclosed is a gain-clamped semiconductor optical amplifier including a semiconductor optical amplifier for amplifying an inputted optical signal and outputting amplified spontaneous emission light, the amplified spontaneous emission light consisting of a first portion and a second portion, the first portion having a wavelength range to be amplified and a wavelength selective reflector for allowing the first portion of the amplified spontaneous emission light to pass through the wavelength selective reflector and reflecting the second portion of the amplified spontaneous emission light again to the semiconductor optical amplifier, thereby clamping the gain of the semiconductor optical amplifier.
Abstract:
The present invention relates to an apparatus and method for detecting the collision of Radio Frequency IDentification (RFID) tags. In the apparatus and method for detecting the collision of RFID tags, when a subcarrier signal from which a carrier signal has been removed by a reader ASK analog demodulation device is inputted to a baseband receiver, a peak signal for the received tag signal is generated, and useful information about the generated peak signal within a symbol section is extracted. In the case where a collision is generated because two or more tags send signals to an RFID reader at the same time when the RFID reader communicates with the tags, the RFID reader can effectively detect the collision between the tags.