• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.137-140
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• 2001

This paper shows an asynchronous comparator circuit for 1.2Gbps signal receiver that converts 1.2Gbps data rate input signals with less than 100㎷ swing to on-chip CMOS compatible voltage levels in a 0.35${\mu}{\textrm}{m}$ CMOS process. Folded-cascode nMOS input stage with source-coupled pMOS input stage cover rail-to-rail input common-mode range. Drastic gain-bandwidth increment due to gain-boosting stage with positive-feedback latch as well as wide input common-mode range make designed circuit be suitable for a fully differential signal receiver. HSPICE simulation results show that worst-case sensitivity is less than 20㎷ and maximum propagation delay is 640-psec. And also we verified 3.97㎽ power consumption with 150㎷ differential swing amplitude at 1.2Gbps.

• Journal of information and communication convergence engineering
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• v.17 no.4
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• pp.285-289
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• 2019

A 1.9-GHz linear CMOS power amplifier is presented. An adaptive bias circuit (ABC) that utilizes an AC ground to detect the power level of the input signal is proposed to enhance the linearity and efficiency of the power amplifier. The ABC utilizes the second harmonic component as the input to mitigate the distortion of the fundamental signal. The input power level of the ABC was detected at the AC ground located at the V_DD node of the power amplifier. The output of the ABC was fed into the inputs of the power stage. The input signal distortion was mitigated by detecting the input power level at the AC ground. The power amplifier was designed using a 180 nm RFCMOS process to evaluate the feasibility of the application of the proposed ABC in the power amplifier. The measured output power and power-added efficiency were improved by 1.7 dB and 2.9%, respectively.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.5
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• pp.45-51
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• 1993

An erbium doped fiber amplifier(EDFA) pumped by aingle 1.48$\mu$m LD was fabricated, and its gain and noise characteristics were measured. As a signal source, 1548 nm wavelength DFB LD was used. The small signal net gain of the EDFA module was 21.8 dB with maximum gain coefficient 0.7dB/mW for the erbium fiber length of 17.6 m, the pump power of 58 mW, and an input signal power of -25 dBm, respectively. The saturation power of the EDFA was 1 dBm for the input signal power of -5 dBm and the noise figure, measured by using an optical spectrum analyzer, was 5.8 dB for the input signal power of -40 dBm.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.65-80
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• 2007

The input and output device requires precise color representation and CMS (Color Management System) because of the increasing number of ways to apply the digital image into electronic publishing. However, there are slight differences in the device dependent color signal among the input and output devices. Also, because of the non-linear conversion of the input signal value to the output signal value, there are color differences between the original copy and the output copy. It seems necessary for device-dependent color information values to change into device-independent color information values. When creating an original copy through electronic publishing, there should be color management with the input and output devices. From the devices' three phases of calibration, characterization and color conversion, the device-dependent color should undergo a color transformation into a device-independent color. In this paper, an experiment was done where the input device used the linear multiple regression and the sRGB color space to perform a color transformation. The output device used the GOG, GOGO and sRGB for the color transformation. After undergoing a color transformation in the input and output devices, the best results were created when the original target underwent a color transformation by the scanner and digital camera input device by the linear multiple regression, and the LCD output device underwent a color transformation by the GOG model.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.240-242
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• 1996

In this paper, we proposed a method of a hearing aid suitable for the sensorineural hearing impaired. Generally as the sensorineural hearing impaired have narrow audible ranges between threshold and discomfortable level, the speech spectrum may easily go beyond their audible range. Therefore speech spectrum must be optimally amplified and compressed into the impaired's audible range. The level and frequency of input speech signal are varied continuously. So we have to make compensation input signal for frequency-gain loss of the impaired, specially in the frequency band which includes much information. The input sigaal is divided into short time block and spectrum within the block is calculated. The frequency-gain characteristic is determined using the calculated spectrum. The number of frequency band and the target gain which will be added input signal are estimated. The input signal within the block is processed by a single digital filter with the calculated frequency-gain characteristics. From the results of monosyllabic speech tests to evaluate the performance of the proposed algorithm, the scores of test were improved.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.285-288
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• 2008

In ubiquitous computing environment the biological signal ECG (Electrocardiogram signal) is usually recorded with noise components. Adaptive interference (or noise) canceller do adaptive filtering of the noise reference input to maximally match and subtract out noise or interference from the primary (signal plus noise) input thereby adaptively eliminate unwanted interference from the ECG signal. Measured Stress ECG (or exercise ECG signal) signal have three major noisy component like baseline wander noise, motion artifact noise and EMG (Electro-mayo-cardiogram) noise. These noises are not only distorted signal but also root of incorrect diagnosis while ECG data are analyzed. Motion artifact and EMG noises behave like wide band spectrum signals, and they considerably do overlapping with the ECG spectrum. Here the multidimensional adaptive method used for filtering which is more effective to improve signal to noise ratio.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.8
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• pp.1491-1496
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• 2009

This paper presents an digital based input/output interface circuit for controlling and monitoring the Diesel Engine Generator for emergency. In order to monitor and control of the Emergency Diesel Engine Generator, controlling and monitoring circuits need 5 analog input channels, 2 pick-up coil measuring circuits, 10 digital input channels containing Broken Wire Detect function, and 7 relay control signal output channels. This system performs signal processing of input signal taking advantage of simple filter circuit, photo-coupler and comparator circuit at analog input parts, and output signals for main relay is designed acting by double control, so it prevents malfunction completely. And it improves accuracy of speed input signal by applying digital circuit that processes rick-up coil signal.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.10
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• pp.863-871
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• 2017

LMS (least mean square) algorithm widely used in the AVCS (active vibration control system) of helicopters calculates control input using the forward path transfer function and error signal. If the error signal is sinusoidal, it can be represented as the combination of cosine and sine functions with frequency and phase synchronized with the reference signal. The control input also has the same frequency, therefore control algorithm can be simply implemented if the cosine and the sine amplitudes of the control input are calculated and the frequency and phase of the reference signal are used. Calculation of the control input is implemented as simple matrix operation and the change of the control command is slower than the frequency of the error signal, consequently control algorithm can be operated at lower frequency. The signal processing algorithm extracting cosine and sine components of the error signals are modeled using Simulink and PIL (processor-in-the-loop) mode simulation was executed for real-time performance evaluation.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.73-76
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• 2001

It is well-known that the convergence rate gets worse when an input signal to an adaptive filter is correlated. In this paper we propose a new adaptive filtering algorithm that makes the convergence rate highly improved even for highly correlated input signals. By introducing an orthogonal constraint between successive input signal vectors, we overcome the slow convergence problem caused by the correlated input signal. Simulation results show that the proposed algorithm yields highly improved convergence speed and excellent tracking capability under both time-invariant and time varying environments, while keeping both computation and implementation simple.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.5
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• pp.808-815
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• 1990

This paper treats with the design method for the single loop oversampled Sigma-Delta A/D converter with one delay and the digital integrator. Such an integrator was kgenerated by means of the bilinear transform of the analog integrator. The frequency spectrums of the quantizer and the decimator output signal are evaluated by FFT respectively. With the performance evaluation system, the values of SNR are obtained versus the input sinusoidal signal amplitude, frequency, the oversampling ratio, the DC-input level, the loop gain and the limitting value of the integrator. As compared with existing results, values of SNR versus the input signal amplitude and the oversampling ratio for the suggested system are about 6dB higher then previously reported results respectively. Furthermore, this approach achieves an about 60dB input dynamic range.