Abstract: The present invention relates to use of a circular buffer used by a peer in a multimedia streaming service based on peer-to-peer (P2P), and an operating method thereof. A circular buffer of the present invention may include a buffering section to process a delayed data fragment transmission request from at least one peer present in a network according to a playback of a multimedia content, a storing section to store data to be provided to the at least one peer, a continuous storing section in which data fragments for the playback of the multimedia content are stored in serial order, and a discontinuous storing section in which a space for a received data fragment to be shared with the at least one peer is reserved and a space for a data fragment to be received is reserved.

Abstract: The present invention provides a method including two operations of a first operation and a second operation. The first operation may determine between a terminal located in a space including the small base station and a terminal located in a space excluding the small base station based on a value reported by a terminal. The second operation may be performed using information received from a neighboring macro base station in response to the determination failing to be performed in the first operation, thereby ultimately discriminating between an area including the small base station and an area excluding the small base station corresponding to a location of a terminal.

Abstract: The apparatus includes a data normalization unit, a neural network problem prediction unit, and a transition change prediction unit. The data normalization unit creates normalization transformation values by performing normalization transformation based on threshold value ranges for a plurality of pieces of vehicle network data. The neural network problem prediction unit creates a neural network problem prediction value by predicting a mixed problem with the vehicle using a multi-artificial neural network model, created based on a learning data set related to mixed problems having previously occurred in the vehicle and the normalization transformation values. The transition change prediction unit predicts a change in transition for the mixed problem according to a change in the neural network problem prediction value, by analyzing the neural network problem prediction value and previous neural network problem prediction values previously created in the vehicle.

Abstract: Provided is a sensorless BLDC motor system. The sensorless BLDC motor system includes a BLDC motor, a comparator, a motor controller, a three-phase inverter, and a mode selector. The BLDC motor includes first to third coils. The comparator compares a voltage of a specific coil of the first to third coils with a neutral-point voltage to output the compared result. The voltage of the specific coil becomes equal to the neutral-point voltage and a specific time elapses, and then the motor controller generates first and second coil control signals based on the compared result. The three-phase inverter supplies a source voltage or ground voltage to the specific coil, or floats the specific coil, in response to the first and second coil control signals. The mode selector selects a driving mode of the BLDC motor by adjusting the specific time.

Abstract: There is provided a portable measuring system having a biophotonic sensor. The portable measuring system also includes a tunable light source, an output intensity detector and an output wavelength detector, which are mounted therein. The portable measuring system can precisely measure a variation in the reflectivity spectrum and/or the transmittance spectrum of the biophotonic sensor before and after an antigen-antibody reaction by varying the wavelength of the tunable light source. Thus, the concentration of the antigen is precisely measured.

Abstract: The present invention relates to an apparatus and method of estimating a channel based on a channel delay spread in a mobile communication system. Pilot subcarriers are inserted between data subcarriers at predetermined intervals to estimate a channel at locations of the pilot subcarriers. An approximate channel delay spread value is estimated by using an autocorrelation value of a pilot signal. Then, a channel for data subcarriers between the pilot subcarriers is estimated by using a Wiener finite impulse response (FIR) filter that has a separate coefficient according to the estimated delay spread value. Accordingly, by changing the Wiener FIR filter coefficient according to the delay spread value of the channel, it is possible to estimate the channel so as to be adaptive for a change of the channel over time. Since the filter coefficients, which are calculated in advance, are used, it is possible to reduce the amount of calculation required when calculating the filter coefficients.

Abstract: A phase-locked loop (PLL) circuit including a voltage-controlled oscillator (VCO) with a variable gain is provided. A phase frequency detector (PFD) detects a phase difference between a reference signal and a PLL feedback signal. A charge pump and a loop filter sequentially process an output signal of the PFD. A VCO has different gains according to a mode transition. A control voltage applied to the VCO is selected from an output signal of the loop filter and an additional control signal according to the mode transition.

Abstract: Provided is an apparatus and method for detecting a horizon which is necessary to detect a camera movement when compositing sea images in a marker-free sea-image camera tracking system. In the method, an ROI is selected near a horizon in a still image of the moving image of the sea, and each maximum point corresponding to the maximum brightness difference is detected from brightness differences between two pixels of each pair having two symmetrical pixels in each column of the ROI. The horizon is detected through a line-fitting using the maximum points. Therefore, the result of horizon detection can be very stable and a horizon can be easily detected in a sea scene having hundreds of frames.

Abstract: Provided are a switching circuit and a small-size high-efficiency direct current-to-direct current (DC-DC) converter for portable devices including the same. Using dynamic threshold-complementary metal oxide semiconductor (DT-CMOS) transistors having dynamic threshold voltages as a switching device, the switching circuit maintains a low threshold voltage in a normal mode to improve current drivability while reducing conduction loss, and maintains a high threshold voltage in a standby mode to minimize power consumption. When the switching circuit is employed in a DC-DC converter, power conversion efficiency can be improved by reducing conduction loss in the normal mode, and power consumption can be minimized in the standby mode. Consequently, the DC-DC converter can maximize a use time of a battery of a portable device and can be useful in power supplies of portable devices that are gradually being miniaturized.

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: Disclosed is a cooperative relay station that relays between a base station and a mobile station when retransmitting a signal. Also, disclosed is a base station that receives a signal from a mobile station in mutual cooperation with the cooperative relay station. After the cooperative relay station receives and decodes a signal that the mobile station transmits to the base station or a service relay station, if an error of the decoded signal does not exist, it stores the received signal. If an error occurs when the base station decodes the signal that the mobile station transmits, the base station requests retransmission for the signal with the error to the cooperative relay station. If the cooperative relay station gets a request of retransmission, it transmits the signal that the base station requests to the base station.

Abstract: Disclosed is a synchronization method between a reader and tag according to an example embodiment, the method including: transmitting, by the reader, a first write command message to the tag at a first time; detecting, by the tag, the first write command message from the reader at a second time and transmitting a first response message to the reader in response to the first write message; transmitting, by the reader, a second write command message including first time information of the first time to the tag; and correcting, by the tag, a clock offset using a difference between the first time and the second time.

Abstract: An apparatus for and method of transmitting and/or receiving a signal by using signaling point rotation in mutually cooperative relaying are provided.

Abstract: A semiconductor laser apparatus is provided which can vary an output wavelength of a light source. A semiconductor laser diode and one or more heat source devices arranged around the semiconductor laser diode are integrated on one substrate. The semiconductor laser diode is configured to be uniformly heated by the heat source device. An output wavelength of the semiconductor laser diode can be easily and quickly varied.

Abstract: A user authentication method and apparatus using a face image are provided. The method includes transforming a face image in a normalized spatial domain into frequency-domain data, extracting valid transform coefficients from the frequency-domain data based on energy-concentrated region information, extracting a feature vector from the extracted valid transform coefficients, and performing user authentication by comparing the extracted feature vector with a previously registered feature vector. Accordingly, it is possible to perform user authentication using a face image while using a minimum data dimension, thereby improving the speed and precision thereof.

Abstract: Provided are an adapter assembly and method for compensating optical fibers for a length difference. The adapter assembly includes a first adapter, a second adapter, and a member. The first adapter is configured to be connected to at least one optical communication unit. The second adapter is configured to be connected to at least another optical communication unit and be coupled to the first adapter. The member is configured to be interposed between the first and second adapters for providing an optical signal transmission path between the optical communication units. Owing to the member, a length difference between optical fibers can be compensated for.

Abstract: An apparatus for hash cryptography has a hardware structure that is capable of providing both secure hash algorithm (SHA)-1 hash calculation and SHA-256 hash calculation. The apparatus for hash cryptography generates a plurality of first message data corresponding to a plurality of first rounds when the SHA-1 hash calculation is performed and generates a plurality of second message data corresponding to a plurality of second rounds when the SHA-256 hash calculation is performed by using one memory, one first register, one XOR calculator, and one OR calculator, calculates a message digest by the SHA-1 hash calculation by using the plurality of first message data when the SHA-1 hash calculation is performed, and calculates a message digest by the SHA-256 by using the plurality of second message data when the SHA-256 hash calculation is performed.

Abstract: There is provided a successive approximation analog-to-digital converter including only minimal capacitors to perform an analog-to-digital conversion operation, thereby making it possible to have very strong process change resistance characteristics while having reduced capacitance and circuit area. The successive approximation analog-to-digital converter may include a reference current supplying unit that supplies a reference current; a signal storage unit that stores a reference signal generated by charging the reference current and an input signal input from the outside; a comparing unit that compares the reference signal and the input signal; and a controller that controls the reference current supplying unit while generating the digital output signal based on the comparison result of the comparing unit to change the supply amount of the reference current supplied to the signal storage unit in proportion to the binary code.

Abstract: There are provided a distributed video coding apparatus and method capable of controlling an encoding rate, the apparatus including: an intra-frame encoder encoding a key frame and outputting a bit stream of the encoded key frame; an encoder rate control (ERC) module calculating a bit rate according to motion complexity of a present Wyner-Ziv (WZ) frame by using a correlation between the motion complexity and the bit rate; and a turbo encoder encoding the present WZ frame by the bit rate calculated at the ERC module and outputting the encoded WZ bit stream.

Abstract: A composite context information management apparatus and a method of providing composite context information using the same. The composite context information management apparatus includes a function providing unit configured to provide a composite context information function corresponding to the operation information from an application control unit; a composite context information processing unit configured to identify pieces of unit contexts and an operation rule based on the composite context information function and the name of the composite context information; and a composite context information presence unit configured to store the pieces of unit contexts corresponding to the name of the composite context information and an instance value for identification of the application and, in response to the application being executed in the user terminal, use the pieces of unit contexts and the operation rule to the user terminal.