Abstract: A transmitter and a signal amplifier are provided. The signal amplifier includes a digital-to-analog converter converting an input digital signal into an analog signal, a local oscillator signal generator outputting in-phase and quadrature-phase oscillator signals, a first mixer mixing the analog signal with the in-phase local oscillator signal to output an in-phase high frequency signal, a second mixer mixing the analog signal with the quadrature-phase local oscillator signal to output a quadrature-phase high frequency signal, a main amplifier amplifying the in-phase high frequency signal output from the first mixer, and an auxiliary amplifier amplifying the quadrature-phase high frequency signal output from the second mixer.

Abstract: A method of manufacturing a semiconductor device comprises forming memory cells on a memory cell region, alternately forming a sacrificial layer and an insulating interlayer on a connection region for providing wirings configured to electrically connect the memory cells, forming an etching mask pattern including etching mask pattern elements on a top sacrificial layer, forming blocking sidewalls on either sidewalls of each of the etching mask pattern element, forming a first photoresist pattern selectively exposing a first blocking sidewall furthermost from the memory cell region and covering the other blocking sidewalls, etching the exposed top sacrificial layer and an insulating interlayer to expose a second sacrificial layer, forming a second photoresist pattern by laterally removing the first photoresist pattern to the extent that a second blocking sidewall is exposed, and etching the exposed top and second sacrificial layers and the insulating interlayers to form a staircase shaped side edge portion.

Abstract: An automatic brightness adjusting method and apparatus for image signal processor (ISP) is provided. The image processing apparatus may include a histogram generating unit, a cumulative distribution function calculator, and a histogram equalization (HE) unit. The histogram generating unit may generate a histogram of brightness values of pixels in an input image. The cumulative distribution function calculator may generate a cumulative distribution function and an inverse cumulative distribution function, based on the generated histogram. The HE unit may generate a conversion function based on the cumulative distribution function and the inverse cumulative distribution function, and may apply HE to the input image based on the conversion function so as to generate an output image.

Abstract: Methods and apparatuses for chaotic communication in a wireless personal area network, A chaotic information carrier is generated for a first predetermined frequency range using a ring-structure oscillator. The ring structure oscillator includes a non-linear element. Chaotic pulses are generated by modulating the chaotic information carrier for the first predetermined frequency range with a data signal. A shape of a spectral density envelope of the chaotic information carrier for the first predetermined frequency range is determined based on a set of parameters which include a first set of values.

Abstract: Disclosed are a mobile robot with a single camera capable of performing a cleaning process with respect to surroundings, and capable of more precisely making a 3D map of the surroundings including a plurality of feature points, and a method for recognizing 3D surroundings of the same. According to the method, images of the surroundings are captured, and a preset number of particles with respect to feature points of a first image are projected to a second image based on matching information of feature points extracted from the two images sequentially captured, thereby extracting 3D information of the surroundings.

Abstract: A PPB-CM communication system and method. The PPB-CM communication system includes a transmitter which splits a symbol period, which is a transmission unit of a communication signal, into at least a pair of parts, inserts a data signal into one of the parts, and transmits a communication signal having the data signal inserted; and a receiver which receives the communication signal from the transmitter and determines bit information of the symbol period according to which part of the symbol period has the data signal inserted, as determined by comparison of energy levels of the parts. Accordingly, a separate threshold is not required to determine the data bit of the symbol period. Thus, the communication signal can be accurately determined. Also, the communication system can be simply implemented without need of a delay line.

Abstract: Methods of forming integrated circuit devices utilize fine width patterning techniques to define conductive or insulating patterns having relatively narrow and relative wide lateral dimensions. A target material layer is formed on a substrate and first and second mask layers of different material are formed in sequence on the target material layer. The second mask layer is selectively etched to define a first pattern therein. Sidewall spacers are formed on opposing sidewalls of the first pattern. The first pattern and sidewall spacers are used collectively as an etching mask during a step to selectively etch the first mask layer to define a second pattern therein. The first pattern is removed to define an opening between the sidewall spacers. The first mask layer is selectively re-etched to convert the second pattern into at least a third pattern, using the sidewall spacers as an etching mask. The target material layer is selectively etched using the third pattern as an etching mask.

Abstract: A radio frequency (RF) communication system having a chaotic signal generator and a method of generating a chaotic signal. The RF communication system includes a chaotic signal generator which generates a chaotic signal having a plurality of frequency components at a predetermined frequency band, a modulator which generates a chaotic carrier by combining the chaotic signal with a data signal which indicates information, and a transmission circuit which includes an antenna to transmit the chaotic carrier made at the modulator. The frequency signal generator comprises an oscillator which converts a DC bias power into a high frequency power, and a resonating unit which generates a wideband signal having a plurality of frequency components by passing a predetermined frequency band of the high frequency power signal.

Abstract: A communication system using a length shift keying (LSK) modulation method provides a transmitter having a carrier signal generator for generating carrier signals, and a modulator for modulating lengths of the carrier signals from the carrier signal generator according to combinations of data bits, and a receiver having an integrator for calculating an energy value by integrating the carrier signal that corresponds to a data bit combination, and a data judgment unit for judging the data bit combination by comparing the energy value with a predetermined threshold value. Power is maintained without changing the bandwidth of a communication signal when the communication signal is modulated.

Abstract: An impulse generation circuit is provided for generating an impulse using a transmission line. Impulse characteristics of the impulse generation circuit are varied with the length of a transmission line rather than the characteristic variation of various devices used therein. The length of the transmission line is adjusted, such that a width of a generated pulse is adjusted. Because an end of the transmission line is short-circuited, the transmission line length can be easily adjusted on a substrate, and a ringing phenomenon due to re-reflection can be removed using termination impedance.

Abstract: Spread spectrum transmission of information is performed using chaotic signals. Direct chaotic communication systems in which information is input to chaotic signal generated directly in information transmission frequency band, are achieved by forming broadband information carrier necessary for transmission and using a chaotic dynamic system whose structure is synthesized in advance in accordance with predetermined characteristics of broadband information carrier to cause chaotic dynamic system to provide operation of forming the broadband information carrier in form of a chaotic information carrier having prescribed spectral characteristics.

Abstract: A signal generator, a signal generation method, and a communication system using the same are provided. The signal generator includes a plurality of nonlinear elements which are connected in a ring; and a signal distributor which is arranged in the ring to form a closed loop, feeds part of a signal to one of the plurality of the nonlinear elements, and outputs signal generated by one of the plurality of nonlinear elements. The method includes arranging a plurality of nonlinear elements connected in a ring; inputting a signal to one of the nonlinear elements; amplifying the signal; receiving the amplified signal and generating a harmonic component of a frequency; clipping the signal; and feeding part of the signal back to one of the nonlinear elements and outputting a remainder of the signal. The system includes a chaotic signal generator; a signal distributor; a modulator; and a transmission circuit.

Abstract: A method of channel coding a digital communication system and a device using the same is provided. The method includes quantizing analog data to digital data, the digital data corresponding to a predetermined number of digital codes; allocating channel codes to the digital codes, as a Hamming distance between a pair of channel codes corresponding to any pair of the digital codes is proportional to a difference between analog values of the pair of the digital codes; and channel coding the digital data by using the channel codes which are allocated to the digital codes to generate channel coded digital data. Accordingly, digital data, such as multimedia digital data without source coding and the like, of which information significance is different may be effectively transmitted and received.

Abstract: An adjustable chaotic signal generator using pulse modulation for UWB communications, and a chaotic signal generating method thereof are provided. The chaotic signal generator for UWB communications includes a plurality of pulse generators which generates pulses of different frequencies; at least one combiner which combines the pulses generated at the pulse generators; and a plurality of local oscillators which receives signals from the combiner, respectively, and generates a chaotic signal by increasing the received signals to different frequency bands. Accordingly, a plurality of users can conduct the radio communications in a specific wireless communication range at the same time by generating the chaotic signal that can be split to the multiple channels. Also, the chaotic signal generator is structured using devices integratable on an integrated circuit.

Abstract: A communication system includes a transmitter having a signal generator for generating a signal for transmitting data, a transmission delay unit for repeatedly delaying the signal from the signal generator for a predetermined delay time within a symbol period and generating corresponding delayed signals, and a selector for selectively providing one of the delayed signals from the transmission delay unit to an antenna; and a receiver having a reception delay unit for receiving the signal from the transmitter and delaying the signal as long as the delay time of the transmission delay unit, and a data judgment block for discriminating data bits of the signal from the transmitter by comparing the signal from the transmitter with the delayed signal from the reception delay unit. According to the communication system, the delay time can be accurately adjusted even if the delay line is shortened, and the data bits of the communication signal can be accurately judged in the receiver side.

Abstract: Spread spectrum transmission of information is performed using chaotic signals. Direct chaotic communication systems in which information is input to chaotic signal generated directly in information transmission frequency band, are achieved by forming broadband information carrier necessary for transmission and using a chaotic dynamic system whose structure is synthesized in advance in accordance with predetermined characteristics of broadband information carrier to cause chaotic dynamic system to provide operation of forming the broadband information carrier in form of a chaotic information carrier having prescribed spectral characteristics.

Abstract: Disclosed is a mobile robot and a controlling method of the same. An entire movement region is divided into a plurality of regions, and a partial map is gradually made by using feature points of a plurality of images of the divided regions. Then, the map is compensated into a closed curved line, thereby making an entire map. Furthermore, when the mobile robot is positioned at a boundary of neighboring regions of the cleaning region, the boundary where a closed curved line is formed, the mobile robot compensates for its position based on a matching result between feature points included in the map, and feature points extracted from images captured during a cleaning process.

Abstract: An apparatus and method for generation of a noise signal are provided. The apparatus includes a noise synthesizing module and a noise signal transfer module. The noise synthesizing module includes a voltage controlled oscillator, a phase frequency detector, a phase locked loop filter, and a reference generator which form a phase locked loop. An output signal of the reference generator is provided to a first phase-frequency input of the phase-frequency detector, and an output signal of the voltage controlled oscillator is provided to a second input of the phase-frequency detector. An output signal of the phase-frequency detector is provided to an input of the phase locked loop filter, and an output of the phase locked loop filter is provided to a frequency control input of the voltage controlled oscillator.

Abstract: A wireless communication system and a method for reducing a ranging time. The communication system includes a main synchronization block group which processes the transceived signal and determines whether the transceived signal is a signal desired by a transmitting device when a receiving device re-transmits the transceived signal to the transmitting device; a ranging block which measures a distance between the transmitting device and the receiving device using a ranging signal when the transceived signal is the desired signal of the transmitting device based on the determination of the main synchronization block group and when the transceived signal is the ranging signal; and a symbol synchronization block which detects a start point and an end point of a symbol forming the signal when the transceived signal from the receiving device is a data communication signal. Accordingly, the fast ranging is feasible and channel occupation time can be shortened.

Abstract: A method and apparatus for simplifying a structure needed to delay data in delay units when a reference signal and data are transmitted by using chaotic signals are provided. The method includes delaying data by at least two delay times, wherein each of the delay times occurs sequentially; multiplexing the data, which has been delayed, according to a control signal; and transmitting the data and a reference signal which corresponds to the data at an interval of delay time. The apparatus includes a first delay unit which is configured to delay data for a first delay time; a second delay unit which is configured to delay the data output from the first delay unit for a second delay time; and a multiplexer which is configured to multiplex the data from the first and second delay units according to a control signal.