• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1754-1766
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• 1993

The application of VXIbus system, an Industry standard, is rapidly spreading with its ability to offer the easiness of integration from GPIB and the fast data transmission from VMEbus system. Compared with VXIbus Register Based Device, VXIbus Message Based Device has a drawback In the aspect of speed. But it is possible to utilize high level ASCII commands to control a Message Based Device, therefore system integration is much easier with Message Based Device than with Register Based Device. And, the FFT analyzer is an instrument for signal analysis which can be inexpensively implemented to be fast and have high resolution. Its wide ability of analysis presents numerous application. So, it is necessary to apply VXIbus system to FFT analyzer. In this paper, the implementation of FFT analyzer is performed using a DSP module and by implementing all A/D conversion circuit and a control module which performs VXIbus interface. The device can be controlled by Slot0 Commender which supports VXIbus Shared Memory Protocol through VXIbus.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.97-102
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• 2016

In this paper, a bidirectional power supply charger is proposed. This system used a solar cell panel to generate electricity and used super capacitors to store these energies, which can be used for the robot cleaner or some other electronic products. This system include a phase-shift controlled bidirectional dual active bridge (DAB) converter, solar panel super capacitors and DSP controller. In the daytime it can charge to the super capacitors to store the energy generated by the solar cell panel and in the night it will release the energy stored in the super capacitors to loads. A prototype of the proposed bidirectional power supply charger system was designed which can achieve 18V to 30V input, 10V/20W output to super capacitors and 9V/6.5W output when it acts as a charger for the robot cleaner. The system is verified to be sTable and reliable by both the simulation and experimental results.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.411-414
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• 1997

This paper describes the design guideline, methodology and general specification of the developed 12 channel interpretive electrocardiograph. The developed 12 channel electrocardiograph consists of main module, patient module, DSP module, interface module, power/battery module, TFT color LCD and thermal recorder. The control panel of the system has full keyboard, rotate/push button, function key and unctional indicators. The graphic user interface program conveniently allows user to record, setup, store, manage ECGs. A variety of system configurations give it ability to make user favorable environment. This system also has a resting adult's ECG analysis program. The developed system and program will be continusely evolved using a database of clinically correlated ECGs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.748-756
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• 2015

In this paper, we developed a miniaturized real time video compression system satisfying the military environment using ADV212 and FPGA. We present an efficient hardware design scheme for the weight reduction of the device and also a software solution to deal with noisy image signals. Experimental results show that the frame delay is reduced by a factor of 2 or 3 and the device's weight is decreased by a factor of 6 to 7. In order to prove the reliability for the military usage of this development, we examine the environmental test (MIL-STD-810G) and EMI test (MIL-STD-461F). Experimental results show that the developed system satisfies the requirements.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.4
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• pp.249-254
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• 2013

A fast multiplier and ADC are essential to process the analog signals in real time. The double-base number system(DBNS) is known as an efficient method for this purpose. The DBNS uses the numbers 2 and 3 as the base numbers simultaneously. The system has an advantage of fast multiplication, less chip area, and low power consumption compared to the binary multiplier. However, the inherent errors of the log number's intrinsic tolerance in DBNS are accumulated in a FIR digital filter, so the signal-to-noise ratio(SNR) has a tendency to be degraded. In this paper, the nonlinear encoder of ADC is designed to compensate the accumulated errors of DBNS by analysing the error distributions of various filter coefficients. The new ADC does not sacrifice its own advantages because the encoder circuits are modified only. The experiments were done with an FIR filters those were designed to have -70dB of SNR in stop band. The proposed nonlinear ADC encoder could drop the SNR to -45dB in stop band, in contrast to -35dB with the linear encoder.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.54-61
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• 2008

This paper presents a new TIQ based CMOS flash 6-bit ADC to process digital signal in real time. In order to improve the conversion speed of ADC by designing new logic or layout of ADC circuits, a new design method is proposed in encoding logic circuits. The proposed encoding circuits convert analog input into digitally encoded double base number system(DBNS), which uses two bases unlike the normal binary representation scheme. The DBNS adopts binary and ternary radix to enhance digital arithmetic processing capability. In the DBNS, the addition and multiplication can be processed with just shift operations only. Finding near canonical representation is the most important work in general DBNS. But the main disadvantage of DBNS representation in ADC is the fan-in problem. Thus, an equal distribution algorithm is developed to solve the fan-in problem after assignment the prime numbers first. The conversion speed of simulation result was 1.6 GSPS, at 1.8V power with the Magna $0.18{\mu}m$ CMOS process, and the maximum power consumption was 38.71mW.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.1
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• pp.82-89
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• 1998

PI controller has been used in the servo system. However the time response of the system designed using the PI control scheme does not provide with desirable time response in case of variation in system parameters or perturbation like a torque disturbance. LMFC(Linear model following controller) is being used to make the response of the system follow that of the model even though the parameter variation or the perturbation occurs. In this paper, a design method, RMFC(Robust Model Following Controller) is proposed, which use an auxiliary model in addition to the LMFC, which affords robustness against the low frequency load torque disturbance. The proposed method is more useful to rejecting the low frequency torque disturbance than LMFC. Proposed method is verified by simulation and experiment.

• Journal of IKEEE
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• v.17 no.2
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• pp.145-150
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• 2013

In the paper, we propose a new CSS(Complex Signed-Signed) CMA(Constant Modulus Algorithm) algorithm for ICS(Interference Cancellation System). When the repeater get the feedback signal, the CSS CMA algorithm is proposed at the ICS repeater using DSP(Digital Signal Processing) for the removal of interfering signals from the feedback paths. The proposed CSS CMA algorithm improved performances and hardware complexity by adjusting step size values. the steady state MSE(Mean Square Error) performance of the proposed CSS CMA algorithm with step size of 0.00043 is about 4dB better than the conventional CMA algorithm. And the proposed Complex Signed Signed CMA algorithm requires 1950 ~ 2150 less iterations than the LMS(Least Mean Square) and Signed LMS(Normalized Least Mean Square) algorithms at MSE of -25dB.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E2
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• pp.66-73
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• 2007

The introduction of tracer gas techniques to ventilation studies in indoor environments provides valuable information that used to be unattainable from conventional testing environments. Data acquisition systems (DASs) containing analogue-to-digital (A/D) converters are usually used to function the key role that records signals to storage in digital format. In the testing process, there exist a number of components in the measuring equipment which may produce system-based inference to the monitored results. These unwanted fluctuations may cause significant error in data analysis, especially when non-linear algorithms are involved. In this study, a pre-processor is developed and applied to separate the unwanted fluctuations (noise or interference) in raw measurements and to reduce the uncertainty in the measurement. Moving average, notch filter, FIR (Finite Impulse Response) filters, and IIR (Infinite Impulse Response) filters are designed and applied to collect the desired information from the raw measurements. Tracer gas concentrations are monitored during leakage and ventilation tests in the model test room. The signal analysis functions are introduced to carry out the digital signal processing (DSP) work. Overall the FIR filters process the $CO_2$ measurement properly for ventilation rate and mean age of air calculations. It is found that, the Kaiser filter was the most applicable digital filter for pre-processing the tracer gas measurements. Although the IIR filters help to reduce the random noise in the data, they cause considerable changes to the filtered data, which is not desirable.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1838-1844
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• 2011

In this paper, the propulsion control of a high-speed maglev train is studied. Electromagnetic suspension is used to levitate the vehicle, and linear synchronous motors (LSM) are used for propulsion. In general, a low-speed maglev train uses a linear induction motor (LIM) for propulsion that is operated under 300[km/h] due to the power-collecting and end-effect problem of LIM. In case of the high-speed maglev train over 500[km/h], a linear synchronous motor (LSM) is more suitable than LIM because of a high-efficiency and high-output properties. An optical barcode positioning system is used to obtain the absolute position of the vehicle due to its wide working distance and ease of installation. However, because the vehicle is working completely contactless, the position measured on the vehicle has to be transmitted to the ground for propulsion control via wireless communication. For this purpose, Bluetooth is used and communication hardware is designed. A propulsion controller using a digital signal processor (DSP) in the ground receives the delayed position information, calculates the required currents, and controls the stator currents through inverters. The performance of the implemented propulsion control is analyzed with a small maglev train which was manufactured for experiments, and the applicability of the high-speed maglev train will be explored.