Abstract: A human body sound transmission apparatus and method for minimizing a signal loss are disclosed. The human body sound transmission apparatus includes: an audio signal transmission unit modulating an audio signal desired to be transmitted, and transmitting the modulated audio signal to the vicinity of a user's ear through the human body (i.e., a user's body); and a carrier wave signal transmission unit transmitting a carrier wave signal for demodulating the modulated audio signal to the vicinity of the user's ear through the air.

Abstract: A frequency selective digital transmission apparatus includes: a preamble transmission processing unit generating a preamble for frame synchronization and spreading the generated preamble with a predetermined spreading code; a header transmission processing unit configuring a header including data attribute information and spreading the header with a predetermined spreading code; a data transmission processing unit performing serial-to-parallel conversion on transmission data according to a selected transmission mode and a spreading scheme and spreading the same with a frequency selective spreading code; and a multiplexing unit multiplexing the preamble, the header, and the data which have been spread by the preamble transmission processing unit, the header transmission processing unit and the data transmission processing unit, respectively, and transmitting the same as digital signals.

Abstract: An ink jet printer module has a module body, an ink inlet port, a washing liquid inlet port and a pneumatic inlet port connected with the main ink tank, the washing liquid tank and the pneumatic pump. A common flow path in the interior of the module body selectively communicates with either the washing liquid flow path or the washing liquid flow path. An ink opening and closing valve is provided at the module body. A pneumatic and washing liquid selection valve is provided in the module body An ink discharge port is provided in the module body discharges the ink of the ink flow path to the outside of the module body. A common discharge port is provided in the module body and discharges either the pneumatic or the washing liquid of the common flow path.

Abstract: Disclosed are a method and an apparatus for amplitude modulation of a spread signal that can increase a data transmission rate and frequency use efficiency by loading information on the amplitude of the spread signal used in digital communications. A method for amplitude modulation of a spread signal according to an exemplary embodiment of the present disclosure includes: receiving a first data signal; generating a spread signal by applying a spreading code to the first data signal; receiving a second data signal; and outputting the spread signal at an amplitude corresponding to a value of the second data signal.

Abstract: The present invention relates to ranging response message generating and processing methods that can reduce overhead in a wireless portable Internet system. A method of generating a ranging response message according to an exemplary embodiment of the present invention includes: adding to the ranging response message a first field indicating the number of responses for CDMA codes included in the ranging response message and received from terminals; adding to the ranging response message second fields indicating ranging code attributes as the responses for the CDMA codes by a value of the first field; and adding to the ranging response message a plurality of third fields indicating transmission parameter adjustment values corresponding to the individual second fields.

Abstract: Provided are a digital communication system using frequency selective baseband and a method thereof. A transmitter of the digital communication system, includes: a preamble/header transmission processing unit for spreading a preamble for frame synchronization and a header including data information; a data transmission processing unit for spreading data by using spread codes having dominant frequency in a desired frequency band, i.e., frequency selective spread codes; and a multiplexer for multiplexing the spreaded preamble and the spreaded header from the preamble/header transmission processing unit and the frequency selective spreaded data from the data transmission processing unit and transmitting the multiplexed signal in digital.

Abstract: Provided is a method of generating and detecting a preamble that may significantly increase accuracy of frame synchronization while avoiding a low frequency domain having great noise power and minimizing hardware complexity and power consumption in a communication system of a digital direct transmission scheme applicable to human body communication. A method of generating a preamble according to an exemplary embodiment of the present disclosure includes: generating a first pseudo noise code and a second pseudo noise code that are different from each other; generating a plurality of same first sub preambles by line-coding the first pseudo noise code; and generating a second sub preamble behind the plurality of first sub preambles by line-coding the second pseudo noise code.

Abstract: The present invention relates to a powerless electronic notepad and a powerless wireless transmission system using the same, and more particularly, to a powerless electronic notepad that stores data recorded on an electronic notepad using piezoelectric elements and transmits the stored data using a passive RFID tag without the use of a power source, and a powerless wireless transmission system using the same.

Abstract: There is provided a communication method using a human body as a medium. A modulation apparatus using a frequency selective baseband according to an aspect of the invention may include: a serial-to-parallel conversion unit converting serial data supplied from an upper layer into parallel data consisting of M+1 number of data input bits; and a frequency selective spreader selecting one subgroup among a plurality of subgroups obtained by dividing 2N number (where N is a positive integer) of spreading codes used for frequency spreading by 2M (where M is a positive integer, and M<N is satisfied), and selecting and outputting one spreading code among 2M number of spreading codes of the one subgroup by using the M number of data input bits, and spreading codes obtained by performing bit circular shifts on the 2M number of spreading codes.

Abstract: Provided are a system and method for human body communication using a limited passband. The system includes a transmission frame generating unit for human body communication which generates a transmission frame for human body communication based on data information including user identification (ID) and data scrambled into an orthogonal code generated by the user ID; a symbol mapping unit for symbolizing the generated transmission frame for human body communication according to a predetermined modulating method; a spreading unit for spreading the symbol outputted in the symbol mapping unit; a waveform generating unit for generating a baseband signal whose band is limited to a predetermined range with respect to the data spread in the spreading unit; and a middle band transmitting unit for modulating the baseband signal into a predetermined limited passband signal.

Abstract: There are provided a receiver in human body communication system using multiple receivers reducing an error rate of receiver signals by applying a space diversity acquisition-related SIMO technology to a plurality of received data using multiple receivers or receiver electrodes in a human body communication system using a human body as a medium, and of stably transmitting the data for the interference of signals generated by other users or from different electronic devices, and a method for receiving data in the human body communication system. The receiver and the method for receiving data in a human body communication system may be useful to stably transmit/receive data without any reduction of its transmission rate by reducing the distortion in channels and the signal noise which are caused in the use of one receiver.

Abstract: A Time Division Duplex (TDD) communication apparatus and an operation method thereof can provide operation clock signals in the transmission and reception of the TDD communication apparatus using a Clock Recovery & Data Retiming (CDR) circuit, thereby stabilizing an operation without any crystal oscillator and reducing the power consumption. In a transmission time interval, a transmitting frame is processed using a clock signal of a reference frequency generated from the CDR circuit. In a reception time interval, a receiving frame is processed using a clock signal recovered from the receiving frame by the CDR circuit.

Abstract: A method and an apparatus for allocating resources in a band adaptive modulation and coding (band AMC) mode of a wideband wireless access system are provided. The method includes, when two or more mobile stations transmit channel quality information (CQI) through an overlapping band, examining whether the mobile stations transmit information indicating that the overlapping band is the highest band thereof, comparing tag values of the mobile stations transmitting the information indicating that the overlapping band is the highest band thereof and selecting one of the tag values having the highest priority, allocating a subchannel corresponding to the highest band to the mobile station having the selected tag value, and changing the tag values of the mobile stations transmitting the information indicating that the overlapping band is the highest band thereof on the basis of the result of the comparison to reset the tag values.

Abstract: Disclosed is an electronic component bonding method which interposes a bonding resin between first and second electronic components to bond the first and second electronic components to each other. The electronic component bonding method includes providing the bonding resin between the first and second electronic components, aligning the first and second electronic components with each other, pre-curing the bonding resin to generate elasticity in the bonding resin, performing a main curing operation to apply vibration energy to the bonding resin, which has elasticity according to pre-curing, to securely fix the first and second electronic component to each other, and control the amplitude of the vibration energy applied during the main curing operation to be restricted within an elastic region of the bonding resin.

Abstract: A transmission device for application to a vehicle is disclosed. The transmission device includes a planetary gear including means for restricting degrees of freedom and a gearbox having two input axles. The root axle of the gearbox is functionally connected to the planetary shaft of carrier or to the planetary shaft of the ring gear. An end portion of the first axle of the gearbox is functionally connected to the root axle via a synchronizing device and the other end portion to the driving axle of the vehicle or to the internal combustion engine. An end portion of the second axle is a free end and the other end portion is connected to the root axle. The second axle has a direction of rotation opposite to that of the root axle and the third axle a direction of rotation opposite to that of the connected planetary shaft.

Abstract: A technique for simultaneously acquiring vehicle identification information and speed information of an RFID tag-attached vehicle by calculating the vehicle speed by using a Doppler shift value extracted from transmission and reception signals between the RFID tag and the RFID reader is disclosed. A method for measuring a vehicle speed by using an RFID reader installed right up on the road or at the roadside includes: transmitting a continuous wave; receiving a reflected wave with respect to the continuous wave from an RFID tag attached to a vehicle which has received the continuous wave; extracting a Doppler shift value from the continuous wave and the reflected wave; and calculating the speed of the vehicle by using the Doppler shift value.

Abstract: An adaptive frequency selective baseband communications method using orthogonal codes includes: a communications testing step of performing communications by using one of a plurality of codes each having a different frequency band; a proper code selecting step of selecting a proper code by using a correlation value of a plurality of codes included in test data transmitted in the communications testing step; a communications performing step of performing communications by using the proper code; and a feedback step of newly selecting a proper code by using the correlation value of the plurality of codes included in the test data transmitted in the communications performing step if a pre-set time duration has lapsed or if a reception error of more than a pre-set reference occurs, and performing the communications performing step again, wherein the test data transmitted in the communications testing step and the communications performing step includes a plurality of codes each having a different frequency band.

Abstract: A receiver in a human communication system includes: receiving electrodes including a transmission frame including control frames and data frames; first and second switches connected with the receiving electrodes; a switching control unit controlling a switching of the first and second switches to selectively connect the receiving electrodes with the first and second switches in response to each control frame according to a predetermined rule every time each of the control frames is input; a signal processing unit performing signal processing on the transmission frame output from the first and second switches; a preamble detection unit detecting the first preamble from each of the control frames included in the signal-processed transmission frame to generate preamble correlation values for the first preamble; and a correlation value processing unit controlling the switching control unit to select pairs of final receiving electrodes among the receiving electrodes based on the preamble correlation values.

Abstract: The present invention relates to an apparatus and method for managing files in a distributed storage system. The apparatus and method for managing a file in a distributed storage system according to the present invention counts the number of inquiries on a file requested by a client; selects the file as a hot file if the number of inquiries counted in a certain counting period is larger than a hot file selection threshold value; and increases the number of copies of the file selected as a hot file or stores the file selected as a hot file in a storage device having a relatively good performance.

Abstract: The present invention relates to an apparatus and method for managing a file in a distributed storage system. The apparatus and method for managing a file in a distributed storage system calculates a retention time of the file based on at least one of a current time, a file creation time, a file modification time and a recent file inquiry time; selects the file as an archive file if the retention time of the file is larger than a predetermined reference time; and relocates an original file and some or all of copy files of the file selected as an archive file from an active server to an archive server or from an active disk to an archive disk.