Abstract: A down-frequency conversion circuit and up-frequency conversion circuit, and a receiver and transmitter applying the same are provided. The down-frequency conversion circuit includes a harmonic mixer and general mixer, and thus becomes able to convert frequency using one LO (Local Oscillator) frequency, thereby reducing burden on generating LO frequency.

Abstract: A radio frequency (RF) switch with a transformer and a switching method thereof are provided. The RF switch includes a transmitting end transformer having a primary side connected to a transmitting end and a secondary side connected to an antenna; and a receiving end transformer having a primary side connected to the antenna and a secondary side connected to a receiving end. In a transmission mode, the transmitting end transformer is tuned on, and, in a reception mode, the receiving end transformer is turned on. Accordingly, since switching is performed based on transformers rather than transistors connected in series, the RS switch, which can achieve high linearity and low insertion loss as well as high isolation, can be implemented.

Abstract: A water treatment apparatus includes a plurality of meshed tubes made of synthetic yarn and provided with cilia; a plurality of tube stack cages containing the meshed tubes; and an aeration diffuser positioned between the tube stack cages and configured to provide air so that to-be-treated influent water moves to the tube stack cages. The hollow interior of the filter media, i.e. meshed tubes, enables water to move in any direction, and the high porosity maximizes the area for filtering of suspended solids and attachment of microorganisms. The resulting efficiency of removal of suspended solids and soluble organic material is far greater than conventional methods. Arrangement of diffusers in the middle of the reaction tank and between the tube stack cages and aeration by them result in perfect mixing in the reaction tank. The load of suspended solids and soluble organic materials is evenly distributed over the entire filer media.

Abstract: An analog-to-digital converter includes: a first latch row corresponding to a first stage; a second latch row corresponding to a second stage; and a digital processor for encoding output signals of the second latch row and generating a digital signal. The first latch row includes a plurality of first latches that receive an analog input signal and reference voltages and operate in synchronization with a first clock signal, and the second latch row includes: a plurality of second latches that receive outputs signals of the plurality of first latches and operate in synchronization with a second clock signal delayed from the first reference clock; and a plurality of third latches that receive output signals of two neighboring latches of the plurality of first latches and operate in synchronization with the second clock signal by means of an interpolation technique.

Abstract: A phase-locked loop based frequency synthesizer generates a plurality of output reference signals by phase-delaying an input reference signal and generates a plurality of comparison signals by using a signal having a frequency divided by the fractional frequency divider. Here, the comparison signals are lower than the divided frequency. Further, the phase-locked loop based frequency synthesizer controls an output frequency of a voltage controlled oscillator through phase and frequency comparison between the plurality of output reference signals and the plurality of comparison signals.

Abstract: A control system connected to a plurality of array antenna performs beamforming. In order to perform the beamforming, the control system receives response beams inputting to a first antenna group predetermined from a plurality of array antenna in response to radiate beams and decides a sector having comparatively stronger intensity. And the control system receives response beams inputting to a second antenna group, decides a plurality of beam levels and decides a final beam pair among the plurality of the decided beam levels.

Abstract: A receiver using a harmonic mixer includes a signal receiver for receiving a first signal, a frequency generator for synchronizing a phase of the received first signal, down-converting a frequency size of the synchronized first signal as much as a first size, and outputting the down-converted signal as a second signal; a first harmonic mixer unit for receiving the first signal and the second signal, generating a third signal having a frequency size down-converted as much as a second size, and outputting the third signal. The receiver further includes a second harmonic mixer unit for receiving the third signal and outputting an In-phase signal having a frequency size down-converted as much as a third size, and a third harmonic mixer unit for receiving the third signal and outputting a Quadrature-phase signal having a frequency size down-converted as much as a third size.

Abstract: A beamforming RF vector modulator is provided. The beamforming RF vector modulator includes a first amplification part for amplifying an input single RF signal and outputting differential RF signals of different phases; an RF signal converter for receiving the differential RF signals and outputting four signals I+, I?, Q+, and Q? of different phases, the RF signal converter comprising a polyphase filter which is virtually opened by resonance of an output terminal comprising a transmission line load; a Variable Gain Amplifier (VGA) part comprising a I VGA which varies an amplitude and a polarity of the signals I+ and I?, and a Q VGA which varies the amplitude and the polarity of the signals Q+ and Q?according to a control signal; and an RF signal synthesizer for synthesizing an output current of the I VGA and an output current of the Q VGA.

Abstract: An analog-to-digital converter includes: a first latch row corresponding to a first stage; a second latch row corresponding to a second stage; and a digital processor for encoding output signals of the second latch row and generating a digital signal. The first latch row includes a plurality of first latches that receive an analog input signal and reference voltages and operate in synchronization with a first clock signal, and the second latch row includes: a plurality of second latches that receive outputs signals of the plurality of first latches and operate in synchronization with a second clock signal delayed from the first reference clock; and a plurality of third latches that receive output signals of two neighboring latches of the plurality of first latches and operate in synchronization with the second clock signal by means of an interpolation technique.

Abstract: A phase-locked loop based frequency synthesizer generates a plurality of output reference signals by phase-delaying an input reference signal and generates a plurality of comparison signals by using a signal having a frequency divided by the fractional frequency divider. Here, the comparison signals are lower than the divided frequency. Further, the phase-locked loop based frequency synthesizer controls an output frequency of a voltage controlled oscillator through phase and frequency comparison between the plurality of output reference signals and the plurality of comparison signals.

Abstract: A beamforming RF vector modulator is provided. The beamforming RF vector modulator includes a first amplification part for amplifying an input single RF signal and outputting differential RF signals of different phases; an RF signal converter for receiving the differential RF signals and outputting four differential signals I+, I?, Q+, and Q? of different phases, the RF signal converter comprising a polyphase filter which is virtually opened by resonance of an output terminal comprising a transmission line load; a Variable Gain Amplifier (VGA) part comprising a I VGA which varies an amplitude and a polarity of the differential signals I+ and I?, and a Q VGA which varies the amplitude and the polarity of the differential signals Q+ and Q?according to a control signal; and an RF signal synthesizer for synthesizing an output current of the I VGA and an output current of the Q VGA.

Abstract: A water treatment apparatus includes a plurality of meshed tubes made of synthetic yarn and provided with cilia; a plurality of tube stack cages containing the meshed tubes; and an aeration diffuser positioned between the tube stack cages and configured to provide air so that to-be-treated influent water moves to the tube stack cages. The hollow interior of the filter media, i.e. meshed tubes, enables water to move in any direction, and the high porosity maximizes the area for filtering of suspended solids and attachment of microorganisms. The resulting efficiency of removal of suspended solids and soluble organic material is far greater than conventional methods. Arrangement of diffusers in the middle of the reaction tank and between the tube stack cages and aeration by them result in perfect mixing in the reaction tank. The load of suspended solids and soluble organic materials is evenly distributed over the entire filer media.

Abstract: A biological removal method of phosphorus and nitrogen includes supplying a mixture gas into a gas holder. Inflow water and return water are supplied into the gas holder to make the mixture gas dissolved in the inflow water and the return water. The return water was provided from a granulation biological reaction tank. The inflow water and the return water including the dissolved mixture gas are transported to the granulation biological reaction tank. A nitrogen-based component is removed from the inflow water and the return water using methan-oxidizing bacteria granulated in the granulation biological reaction tank. Treated water without the nitrogen-based component is transported to an anoxic tank for treatment, and discharged from the anoxic tank.

Abstract: A biological removal method of phosphorus and nitrogen includes supplying a mixture gas into a gas holder. Inflow water and return water are supplied into the gas holder to make the mixture gas dissolved in the inflow water and the return water. The return water was provided from a granulation biological reaction tank. The inflow water and the return water including the dissolved mixture gas are transported to the granulation biological reaction tank. A nitrogen-based component is removed from the inflow water and the return water using methan-oxidizing bacteria granulated in the granulation biological reaction tank. Treated water without the nitrogen-based component is transported to an anoxic tank for treatment, and discharged from the anoxic tank.

Abstract: A biological removal method of phosphorus and nitrogen includes supplying a mixture gas into a gas holder. Inflow water and return water are supplied into the gas holder to make the mixture gas dissolved in the inflow water and the return water. The return water was provided from a granulation biological reaction tank. The inflow water and the return water including the dissolved mixture gas are transported to the granulation biological reaction tank. A nitrogen-based component is removed from the inflow water and the return water using methan-oxidizing bacteria granulated in the granulation biological reaction tank. Treated water without the nitrogen-based component is transported to an anoxic tank for treatment, and discharged from the anoxic tank.

Abstract: An apparatus and method for reproducing moving image stream with speed change, are discussed. According to an embodiment, the apparatus includes a receiving unit configured to receive a compressed moving image stream, a reconstruction unit configured to reconstruct an image from the compressed moving image stream, a generation unit configured to generate a still image from the reconstructed image, a recording unit configured to record the generated still image and a reproduction unit configured to perform a trick mode using the still image.

Abstract: A biological removal method of phosphorus and nitrogen includes supplying a mixture gas into a gas holder. Inflow water and return water are supplied into the gas holder to make the mixture gas dissolved in the inflow water and the return water. The return water was provided from a granulation biological reaction tank. The inflow water and the return water including the dissolved mixture gas are transported to the granulation biological reaction tank. A nitrogen-based component is removed from the inflow water and the return water using methan-oxidizing bacteria granulated in the granulation biological reaction tank. Treated water without the nitrogen-based component is transported to an anoxic tank for treatment, and discharged from the anoxic tank.

Abstract: Provided is an apparatus for processing sewage by granulating activated sludge and a method thereof. The sewage processing apparatus includes an anaerobic granulation tank for granulating suspended microorganisms; an indirect aeration tank for supplying oxygen to the supernatant transported through a first transport pipe; an aerobic granulation tank for granulating suspended microorganisms; and a discharge pipe for discharging supernatant of finished water obtained after circulating a series of the anaerobic granulation tank, the first transport pipe, the indirect aeration tank, the aerobic granulation tank repeatedly.

Abstract: A variable gain control circuit is provided comprising a bipolar transistor for amplifying an input signal applied to a base, and outputs an output signal via a collector; a serial exchanging unit connected between an emitter of the bipolar transistor; a first voltage node; a parallel exchanging unit connected between the collector of the bipolar transistor and the first voltage node, and wherein the gain of the variable gain control circuit increases in a high gain mode by activating the serial exchanging unit and deactivating the parallel exchanging unit, and the gain of the variable gain control circuit decreases in a low gain mode by deactivating the serial exchanging unit and activating the parallel exchanging unit.

Abstract: Provided is an apparatus for processing sewage by granulating activated sludge and a method thereof.