Abstract: A passive phase jitter modulation (PJM) tag is charged with power in a continuous wave (CW) section. When receiving a command from a reader, the passive PJM tag must recognize the command and determine exactly when to begin demodulating the command. Only then can the passive PJM tag demodulate the command. To this end, a synchronization apparatus for accurately demodulating a signal input to a PJM tag includes a plurality of correlators correlating a received phase jitter-modulated signal with a template of an internal matched filter which is in the same form as at least a portion of a modified frequency modulation (MFM) flag.

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 Radio Frequency identification (RFID) system and method for protecting information. The system includes: an identification information storing unit which includes identification information and generates an interrupt/interference signal to block access without permission; an RFID calling unit which reads information of the identification information storing unit by loading a basic protocol and a security protocol for recognizing the identification information storing unit; and a storing unit which registers and stores information required for authentication between the RFID calling unit and the identification information storing unit, and information required for access control.

Abstract: Satellite image fusion method and system are provided. The satellite image fusion method includes matching sizes of a panchromatic image and a multispectral image captured from a satellite image; dividing the panchromatic image and the multispectral image into a plurality of blocks; calculating coefficients to acquire Intensity (I) component image data using pixel values of each block of the multispectral image; and generating fused multispectral image data by applying the acquired I component image data to a fusion algorithm. In the multispectral image fusion, the distortion of the color information can be minimized and the multispectral image data of the high resolution can be attained. In addition, the present invention is applicable to not only the IKONOS images but also other satellite images, and the present image fusion can be carried out fast.

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: Provided is a power amplifier sharing system for a mobile communication system having a mobile Radio Frequency Identification (RFID) function, particularly, a power amplifier sharing system that can reduce the power consumption and the size of a circuit in a mobile communication terminal having a mobile RFID function. The system includes a mobile communication transceiver for transmitting/receiving a mobile communication signal; a mobile RFID transceiver for transmitting/receiving a mobile RFID signal; a power amplifier for amplifying a signal; a switch for connecting the mobile communication transceiver and the mobile RFID transceiver to the power amplifier; and a transceiver controller for controlling the switch and the power amplifier.

Abstract: Provided is a Radio Frequency Identification (RFID) reader that can minimize collision among RFID readers in an environment where there are a plurality of RFID readers within a limited operating environment by making each RFID reader select a channel at different delay time based on a random value, and a method for controlling operation of the RFID reader. The RFID reader includes a random value generating unit; a reader control unit for adaptively deciding a counter value for generating the random value; an anti-collision unit for preventing collision among a plurality of tags; a reader transmitting unit for generating a reader command message determined by the anti-collision unit, encoding the reader command message, and modulating the reader command message; a reader receiving unit for demodulating and decoding a tag signal; and a channel operation control unit for selecting a channel to be used for the communication with the tag.

Abstract: Provided is a method for reading a tag in a mobile Radio Frequency Identification (RFID) environment. The tag reading method effectively identifies a tag by repeatedly transmitting a tag identification request in a predetermined time to prevent collision among RFID readers, when a plurality of RFID readers access to a tag. The method for reading a tag in a mobile RFID environment, which includes the steps of: a) transmitting a tag identification request signal to a tag; b) waiting for an acknowledgement signal to be transmitted from the tag; and c) when no acknowledgement signal is transmitted from the tag, retransmitting the tag identification request signal after a predetermined delay time passes.

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 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 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 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: An apparatus and method for reading multiple tags with different protocols in a RFID system are provided. The method of reading multiple tags with different protocols in a RFID system including the steps of: a) setting scheduling parameters including target protocols to read, priorities of each protocol, and information about a scheduling algorithm mode for reading multiple tags; b) reading tags of a single protocol corresponding to the target protocol when the scheduling algorithm mode is a single mode; and c) reading multiple tags by the target protocols when the scheduling algorithm mode is a multi mode.

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: Provided are a mobile RFID reader and a control method thereof. The mobile RFID reader includes: a reader controller for beginning a reader operation to communicate with a tag in response to a command of a terminal controller of the wireless communication terminal; an anti-collision state machine for controlling collision among a plurality of tags, and transferring the result of communication with the tag to the reader controller; a reader transmitter for generating a reader command message decided at the anti-collision state machine, and coding and modulating the generated reader command message; a reader receiver for demodulating and decoding a tag signal received through an antenna, and reporting a tag response state to the anti-collision state machine; and a channel controller for selecting a channel to use to communicate with a tag in response to a command of the reader controller.

Abstract: Provided are a tag signal receiving apparatus that can perform digital Amplitude Shift Keying (ASK) demodulation onto signals received in a tag, decode the demodulated tag signal in synchronization, and acquire tag data in a mobile RFID reader, and a method thereof. The tag signal receiving apparatus includes: a digital demodulating block for performing ASK demodulation onto a digital tag signal received through a reader antenna and converted into a digital tag signal in an analog-to-digital (AD) converter; and a decoding block for detecting edge position information of the demodulated tag signal by performing accumulation and decoding the demodulated tag signal by using the detected edge position information. The digital demodulating block includes a channel level comparator, a phase inverter, a signal converter; and an adder. The decoding block includes an edge information detector, a correlator, and a bit data decider.

Abstract: Provided is a Radio Frequency identification (RFID) system and method for protecting information. The system includes: an identification information storing unit which includes identification information and generates an interrupt/interference signal to block access without permission; an RFID calling unit which reads information of the identification information storing unit by loading a basic protocol and a security protocol for recognizing the identification information storing unit; and a storing unit which registers and stores information required for authentication between the RFID calling unit and the identification information storing unit, and information required for access control.

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: The present invention relates to an optical communication, and more particularly, to a wideband wavelength division multiplexing (WDM) optical communication system which can have a broad amplification band while overcoming a polarization dependency and solving a signal leakage between channels. In an optical amplifier module and optical transmission system for a WDM optical communication system using this, the optical amplifier module uses a semiconductor quantum dot optical amplifier as an amplifying means, and thus has a wide amplification bard and has no a polarization dependency of a gain and a signal leakage between channels, and the optical transmision system uses a semiconductor quantum dot optical amplifier module when several optical amplifier modules are connected for use so that a gain automatically becomes flat and automatically becomes fixed even though a channel number and an input signal size become different.