Abstract: A semiconductor device including a first interlayer insulating film; a conductive pattern in the first interlayer insulating film; a resistance pattern on the conductive pattern; an upper etching stopper film spaced apart from the resistance pattern, extending in parallel with a top surface of the resistance pattern, and including a first metal; a lower etching stopper film on the conductive pattern, extending in parallel with a top surface of the first interlayer insulating film, and including a second metal; and a second interlayer insulating film on the upper etching stopper film and the lower etching stopper film, wherein a distance from a top surface of the second interlayer insulating film to a top surface of the upper etching stopper film is smaller than a distance from the top surface of the second interlayer insulating film to a top surface of the lower etching stopper film.

Abstract: A method of lithographic masking for spatially localized biochemical stimulus delivery, comprising the steps of providing a group of cells on a substrate, coating a layer of gelatin on a portion of the cells, creating a mask layer on a portion of the layer of gelatin on a portion of the cells, and creating an area of masked cells and an area of unmasked cells. Further, the method can include delivering a biochemical signal to the area of unmasked cells, removing the mask layer, and allowing the cells with the biochemical signal and the cells without the biochemical signal to interact freely.

Abstract: An flash memory device includes a block of NAND cell units, each NAND cell unit in the block includes n memory cell transistors MC controlled by a plurality of n wordlines, and is connected in series between a string selection transistor SST connected to a bitline and a ground selection transistor GST. While a programming voltage Vpgm is applied to a selected wordline WL<i>, a cutoff voltage Vss is applied to a nearby unselected wordline closer to the ground selection transistor GST to isolate a first local channel Ch1 from a second local channel Ch2. As the location i of the selected wordline WL<i> increases close to the SST, the second channel potential Vch2 tends to increase excessively, causing errors.

Abstract: Disclosed herein are a tube for arteriovenous anastomosis useful in hemodialysis patients and an insert for use in medicinal operation in the body. The tube or the insert are repetitively treated with a medicament on the surface thereof, which provides stable communication between an artery and a vein of a patient under hemodialysis and can greatly reduce stenosis at arteriovenous connections by releasing the medicament at a suitable rate over a prolonged period of time.

Abstract: A reference frequency generation method and apparatus for communication systems that transmit and receive data by use of an ultra wide band of at least two frequency groups having at least two reference frequencies. The method and apparatus generate the reference frequencies by generating generation frequencies by use of a frequency generated from the local oscillator, and generating adjustment frequencies for adjusting the generation frequency. One generation frequency and one adjustment frequency are selected from the generation frequencies and adjustment frequencies, and the reference frequencies are generated by use of the selected generation frequency and adjustment frequency.

Abstract: A signal reception apparatus and method for communication systems. The signal reception apparatus for communication systems according to the present invention is applicable to communication environments in which a plurality of sub-bands having different frequency bands are sequentially used for communications. An embodiment of the invention has a multi-band index generation unit, a multi-band frequency generation unit, a multiplication unit, a correlation signal reception unit, and a buffer unit. The multi-band index generation unit generates a multi-band index corresponding to a sub-band to which a received signal is transmitted in correspondence with the multi-band index. The multiplication unit outputs a signal obtained by multiplying the received signal by the multi-band frequency. The correlation signal reception unit integrates and outputs the signal of the multiplication unit based on an integral time set in correspondence with the multi-band index.

Abstract: A method for reference signal generating in an ultra wideband (UWB) communication system which sends out and receives data by using at least two reference signals of predetermined frequencies. A first signal group, which comprises a local oscillation (LO) signal and a signal at a predetermined phase difference with respect to the LO signal, is generated. One among at least two intermediate frequency (IF) signals is selected for the adjustment of the frequency of the LO signals, and a second signal group, which comprises the selected IF signal and a signal at a predetermined phase difference with respect to the selected IF signal, is generated. Two mixed signals are generated from the first and the second signal groups, the mixed signals being mixed without overlap, and a reference signal is generated by adding the two generated signals.

Abstract: A frequency generation apparatus and a method are provided. The frequency generation apparatus for generating a plurality of center frequencies for use in multi-band hopping communication, includes: an oscillator generating an oscillation frequency; a reference frequency generator multiplying the oscillation frequency by a first multiplication rate to generate a reference frequency; a compensation frequency generator multiplying the oscillation frequency by a second multiplication rate to generate a compensation frequency for compensating for the influence of a frequency offset of the oscillation frequency; and a center frequency generator generating the plurality of center frequencies using the reference frequency and the compensation frequency. Therefore, by compensating for the influence of a frequency offset of an oscillation frequency on the generation of center frequencies, it is possible to generate stable center frequencies.

Abstract: An apparatus and method for generating an intermediate frequency (IF) to be transferred to a single sideband (SSB) generator which generates carriers using one local oscillator (LO) signal and at least two IF signals that are received. A group signal is generated which includes a non-phase-shifted signal and a phase-shifted signal to a predetermined value with respect to each IF. One of the group signals is selected and transferred to the SSB generator. Accordingly, the SSB generator performs the phase shift on the LO signal alone.

Abstract: A frequency generation apparatus and a method are provided. The frequency generation apparatus for generating a plurality of center frequencies for use in multi-band hopping communication, includes: an oscillator generating an oscillation frequency; a reference frequency generator multiplying the oscillation frequency by a first multiplication rate to generate a reference frequency; a compensation frequency generator multiplying the oscillation frequency by a second multiplication rate to generate a compensation frequency for compensating for the influence of a frequency offset of the oscillation frequency; and a center frequency generator generating the plurality of center frequencies using the reference frequency and the compensation frequency. Therefore, by compensating for the influence of a frequency offset of an oscillation frequency on the generation of center frequencies, it is possible to generate stable center frequencies.

Abstract: A reference frequency generation method and apparatus for communication systems that transmit and receive data by use of an ultra wide band of at least two frequency groups having at least two reference frequencies. The method and apparatus generate the reference frequencies by generating generation frequencies by use of a frequency generated from the local oscillator, and generating adjustment frequencies for adjusting the generation frequency. One generation frequency and one adjustment frequency are selected from the generation frequencies and adjustment frequencies, and the reference frequencies are generated by use of the selected generation frequency and adjustment frequency.

Abstract: Disclosed is a noncoherent pulse position and phase shift keying (PPPSK) transmission/reception system and a transmission/reception signal processing method therefor. Transmission system has an information generation unit for generating information data; a modulation unit for deciding a phase and a timing position corresponding to generated information data; and a wavelet generation unit for generating a wavelet based on the decided phase and timing position, and the reception system has an offset unit for mixing the reception signal with a high-frequency component corresponding to a center frequency of a transmission frequency band and offsetting a high frequency of the reception signal; a demodulation unit for generating at least one reference signal based on a previous signal precedingly received with respect to the reception signal and mixing the reference signals and the reception signal; and a decision unit for deciding information data corresponding to the reception signal based on mixing results.

Abstract: A signal reception apparatus and method for communication systems. The signal reception apparatus for communication systems according to the present invention is applicable to communication environments in which a plurality of sub-bands having different frequency bands are sequentially used for communications. An embodiment of the invention has a multi-band index generation unit, a multi-band frequency generation unit, a multiplication unit, a correlation signal reception unit, and a buffer unit. The multi-band index generation unit generates a multi-band index corresponding to a sub-band to which a received signal is transmitted in correspondence with the multi-band index. The multiplication unit outputs a signal obtained by multiplying the received signal by the multi-band frequency. The correlation signal reception unit integrates and outputs the signal of the multiplication unit based on an integral time set in correspondence with the multi-band index.

Abstract: A method for reference signal generating in an ultra wideband (UWB) communication system which sends out and receives data by using at least two reference signals of predetermined frequencies. A first signal group, which comprises a local oscillation (LO) signal and a signal at a predetermined phase difference with respect to the LO signal, is generated. One among at least two intermediate frequency (IF) signals is selected for the adjustment of the frequency of the LO signals, and a second signal group, which comprises the selected IF signal and a signal at a predetermined phase difference with respect to the selected IF signal, is generated. Two mixed signals are generated from the first and the second signal groups, the mixed signals being mixed without overlap, and a reference signal is generated by adding the two generated signals.

Abstract: An apparatus and method for generating an intermediate frequency (IF) to be transferred to a single sideband (SSB) generator which generates carriers using one local oscillator (LO) signal and at least two IF signals that are received. A group signal is generated which includes a non-phase-shifted signal and a phase-shifted signal to a predetermined value with respect to each IF. One of the group signals is selected and transferred to the SSB generator. Accordingly, the SSB generator performs the phase shift on the LO signal alone.

Abstract: An ultra wideband (UWB) wireless transmitter includes a first pulse generator for modulating data to be transmitted and outputting a first linear modulated signal, a second pulse generator for modulating the data to be transmitted and outputting a second linear modulated signal, an adder for adding the first and the second linear modulated signals, a pulse shaper for shaping the signal output from the adder, a carrier generator for outputting a carrier, a mixer for mixing the signal output from the pulse shaper with the carrier, a transmission unit for transmitting the signal output from the mixer, and a controller for controlling the modulation of the signal to be transmitted by controlling the operation of the first and the second pulse generators and the carrier generator. As a result, a data transmission rate can be greatly increased without having any inter-pulse interference even when the pulse intervals are reduced.

Abstract: Disclosed is a noncoherent pulse position and phase shift keying (PPPSK) transmission/reception system and a transmission/reception signal processing method therefor. Transmission system has an information generation unit for generating information data; a modulation unit for deciding a phase and a timing position corresponding to generated information data; and a wavelet generation unit for generating a wavelet based on the decided phase and timing position, and the reception system has an offset unit for mixing the reception signal with a high-frequency component corresponding to a center frequency of a transmission frequency band and offsetting a high frequency of the reception signal; a demodulation unit for generating at least one reference signal based on a previous signal precedingly received with respect to the reception signal and mixing the reference signals and the reception signal; and a decision unit for deciding information data corresponding to the reception signal based on mixing results.