• Journal of Convergence for Information Technology
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• v.9 no.1
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• pp.136-141
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• 2019

In this paper, we describe the design of a small size data acquisition system with STM32 processor based on Cortex-M4. The system is used for the sensor devices to collect raw data on production lines at factory and send them to the server computer in real time. Also the system is designed to easily acquisite various kinds of data collected from various sensors with the digital signal input unit, the analog signal input unit, the digital signal output unit and the analog signal output unit This small data acquisition system will contribute to the improvement of the quality of precision products in the industrial field by collecting various data in real time and transmitting data at high speed.

• Journal of IKEEE
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• v.23 no.3
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• pp.1082-1087
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• 2019

In this study, ECG signal amplifier, wireless transmitter/receiver circuit, signal processing filter circuit and A/D converter circuit design required for the development of small sized ECG module for wireless transmission/ reception were performed. In order to verify the performance of ECG sensors, the measurement was performed from 1 m to 3 m to measure the signal noise ratio according to the gateway distance. Experimental results showed that the signal noise ratio at 2 m distance was 17.18 dB on average, which fulfilled the requirements for commercialization. The experimental results obtained in this study are expected to contribute to the low cost, high efficiency mobile health field where remote monitoring diagnosis can be applied to small biometric devices for chronic disease management.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.1119-1122
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• 2000

This paper describes on RF circuit simulation technique, especially on a RF modeling and a model extraction of a LDMOS(Lateral Diffused MOS) that has gate-width (Wg) dependence. Small-signal model parameters of the LDMOSs with various gate-widths extracted from S-parameter data are applied to make the relation between the RF performances and gate-width. It is proved that a source inductance (Ls) was not applicable to scaling rules. These extracted small-signal model parameters are also utilized to remove extrinsic elements in an extraction of a large-signal model (using HP Root MOSFET Model). Therefore, we can omit an additional measurement to extract extrinsic elements. When the large-signal model with Ls having the above gate-width dependence is applied to a high-power LDMOS module, the simulated performances (Output power, etc.) are in a good agreement with experimental results. It is proved that our extracted model and RF circuit simulation have a good accuracy.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2247-2252
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• 2009

Since the dimensions of MEMS gyroscope are very small compared to those of conventional gyroscope, MEMS gyroscope should be able to measure charge of pico-coulomb caused by very small change of electrodes gap. However, feed-through signal from driving electrodes to the sensing electrodes due to the electromagnetic coupling is much greater than the sensing signal, which degrades the sensitivity of MEMS gyroscope. This paper introduces the feed-through noise canceling technique using dummy port and confirms the feasibility of feed-through noise canceling experimentally. Experimental results shows that, when driving signal is 6 Vpp, 30 kHz, feed-through signal of vacuum packaged Si Gyroscope decreases from -53.2 dBm to -77.1 dBm by using feed-through reduction technique. Q-factor that could not be measured without noise reduction is measured to be about 2500 and resonance frequency to be 7.018 kHz.

• The Journal of the Acoustical Society of Korea
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• v.37 no.1
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• pp.39-45
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• 2018

Compressive sensing allows recovering an original signal which has a small dimension of the signal compared to the dimension of the entire signal in a short period of time through a small number of observations. In this paper, we proposed a method for detecting tonal signal which caused by the machinery component of a vessel such as an engine, gearbox, and support elements. The tonal signal can be modeled as the sparse signal in the frequency domain when it compares to whole spectrum range. Thus, the target tonal signal can be estimated by S-OMP (Simultaneous-Orthogonal Matching Pursuit) which is one of the sparse signal recovery algorithms. In simulation section, we showed that S-OMP algorithm estimated more precise frequencies than the conventional FFT (Fast Fourier Transform) thresholding algorithm in low SNR (Signal to Noise Ratio) region.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.875-876
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• 2008

Parametric stereo coding is a technique to efficiently code a stereo audio signal as a monaural signal plus small amount of parametric overhead to describe the stereo image. The stereo properties are analyzed, encoded, and reinstated in a decoder according to spatial psycho-acoustical principles. However, coding of multichannel audio signal using parametric stereo still requires considerable bit-rate. In this paper, enhanced parametric stereo coding for multichannel audio signal is proposed.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.35-39
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• 2015

This study was presented the small action by the budge sonance function. An estimation of budge sonance function was acquired displacements across all condition with a variation of small action. The budge sonance function was to be indicated to express the flow rate of body motion. Their function was suggested an issue of the action condition by budge sonance. This system was proposed a combination of the body motion and small action. The acquired sonance signal was to render the small action of body motion with budge sonance function. The analysis of budge function was generally realized a variation from displacements on the fast body motion. Budge sonance signal of action that vision condition was acquired to a variation of the $Vi-{\beta}_{AVG}$ with $(-4.954){\pm}(-5.42)$ units, that vestibular condition was acquired to a variation for the $Ve-{\beta}_{AVG}$ with $(-2.288){\pm}0.212$ units, that somatosensory condition was acquired to a variation for the $So-{\beta}_{AVG}$ with $(-0.47){\pm}0.511$ units, that CNS condition was acquired to a variation for the $C-{\beta}_{AVG}$ with $(-0.171){\pm}(-0.012)$ units. Budge sonance function was proposed the small action from axial action on body control. We know a body motion response from axial action was not only variation of budge sonance, but also body motion of fast body motion.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.6
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• pp.1-4
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• 1975

This paper dells with the impedance variations of the IMPATT diode depending upon the small a.c. coomponent superimposed on the d.c. bias. The frequency deviation of the modulated wave is measured using a carrier null method on microwave spectrum analyser. Frequency modulation is achieved by the weack a.c. signal superimposed on the d.c. bias. The bandwidth rapidly increase with increasing modulation signal magnitude for constant modulation frquency and slightly decrease with decreasing modulation frequency for constant modulation signal magnitude.

• Smart Structures and Systems
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• v.19 no.5
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• pp.499-512
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• 2017

Traditional structural dynamic analysis and Structural Health Monitoring (SHM) of large scale concrete civil structures rely on manufactured embedding transducers to obtain structural dynamic properties. However, the embedding of manufactured transducers is very expensive and low efficiency for signal acquisition. In dynamic structural analysis and SHM areas, piezoelectric transducers are more and more popular due to the advantages like quick response, low cost and adaptability to different sizes. In this paper, the applicable feasibility assessment of the designed "artificial" piezoelectric transducers called Concrete Piezoelectric Smart Module (CPSM) in dynamic structural analysis is performed via three major experiments. Experimental Modal Analysis (EMA) based on Ibrahim Time Domain (ITD) Method is applied to experimentally extract modal parameters. Numerical modal analysis by finite element method (FEM) modeling is also performed for comparison. First ten order modal parameters are identified by EMA using CPSMs, PCBs and FEM modeling. Comparisons are made between CPSMs and PCBs, between FEM and CPSMs extracted modal parameters. Results show that Power Spectral Density by CPSMs and PCBs are similar, CPSMs acquired signal amplitudes can be used to predict concrete compressive strength. Modal parameter (natural frequencies) identified from CPSMs acquired signal and PCBs acquired signal are different in a very small range (~3%), and extracted natural frequencies from CPSMs acquired signal and FEM results are in an allowable small range (~5%) as well. Therefore, CPSMs are applicable for signal acquisition of dynamic responses and can be used in dynamic modal analysis, structural health monitoring and related areas.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.12
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• pp.1366-1381
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• 1991

The error rate equation of QPSK signal received through m-distribution fading channel in tone interference and Gaussian noise environments has been derived and evaluated numerically to be shown in figures. The derivation has been done for two cases. The one case is that only the signal is under the influence of fading and the another case is that signal and interference are under the influence of fading simultaneously. The evaluated results show that the error that performance when fading influences signal and interference simultaneously is worse than that when fading influence signal only. Also the results show that a late amount of improvement can be gained by direct sequence spread spectrum system and the amount of improvement becomes small as the influence of interference and fading becomes small.