• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.3
• /
• pp.507-513
• /
• 2008

In this study, we develope an ambulatory ECG acquisition system by implementing a patch-style and wireless electrode. To alleviate the inherent noisy characteristics of the mobile signal, we apply a matched filter and concurrently detect R-peak values. Moreover, the measure for resolving shape distance is computed to estimate the relative similarity between two ECG signals and to decide whether the abnormal characteristics in ECG exist or not.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.5
• /
• pp.1230-1239
• /
• 1996

This paper analyzes matched-filter acquistion performance of a direct-sequence spread-specturm multiple-access system in a Rayleigh fading channel. For an application of multiple access system, multiple access interference is considered in the performance analysis. A signal flow graph technique is used to derive mean acquisition time in terms of detection and false alarm probabilities. As aresult of performance analysis, it is shown that mean acquisition time increases as fading rate becomes faster andthe numbre of users increases, and it decreases as a matched-filter length becomes logner. The variation of parameter values hs much influence on acquisition performance as SNR/chip becomes smaller.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.5
• /
• pp.1-13
• /
• 1995

In this paper, we evaluated the mean acquisition time and it's variance of the rapid synchronization system using the DMF(Digital Matched Filter) under the DS/CDMA system which uses the long period PN code. And we implemented the synchronization system that satisfies the specification demanded by the proposed EIA/TIA Interim Standard of Qualcomm Company. We showed that the state of the PN spreading code was estimated using the DMF(Digital Matched Filter) and then exact and fast chip synchronization could be achieved by the early-late tracking loop in the multiple channel environment. And we suggested the possibility that this synchronization system could be useful in the emerging digital cellular DS/CDMA system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.450-455
• /
• 2009

Amplitude-only logarithmic Radon transform (ALR transform) for pattern matching is proposed. This method provides robustness for object translation, scaling, and rotation. An ALR image is invariant even if objects are translated in a picture. For the object scaling and rotation, the ALR image is merely translated. The objects are identified using a phase-only matched filter to the ALR image. The ratio of size, the difference of rotation angle, and the position between the two objects are detected. Our pattern matching procedure is described, herein, and its simulation is executed. We compare matching scores with the Fourier-Mellin transform, and the general phase-only matched filter.

• Journal of Biomedical Engineering Research
• /
• v.11 no.2
• /
• pp.209-216
• /
• 1990

Pulmonary nodules in chest X-Ray images were detected using the symmetric property of human lung and its performance was evaluated. Thls algorithm reduced the effect of background components and enhanced the nodule signals relatively. The image was divided and processed separately, the half with matched filter only, and the other half with warping and matched filter. This algorithm increased the entire detection rate by reducing False-Positive error and improving True-Positive detectability. Result shows 10-25 % improvement in detection rate compared with the conventional alsorithm for nodules size of 10mm.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.3
• /
• pp.684-691
• /
• 1996

Since the period of a spreading code in DS/SS communication systems is generally long, it is necessary to make the code acquisition as fast as possible. The code acquisition time can be sued as a measure to evaluate the performance of code acquisition systems. The search rate of serial search codee acquisition system used in the coventional CDMA cellular system is lower than that of the matched filter technique. In order to reduce the code acquisition time, this paper proposes hybrid code acquisition system composed filters combined with serial search blocks. In the proposed system, the matched filter sweeps possible code phases fast and the acquired phase information is verified by the serial search block. The mean and the variance of its acquisition time are calculated and compared with those of double dwell serial search system. The results indicate better performance of the proposed system by yielding its small vaues of the mean and the variance of code acquisition time.

• The Journal of the Acoustical Society of Korea
• /
• v.6 no.1
• /
• pp.5-14
• /
• 1987

In this paper, the transmission characteristics of a frequency-hopped spread spectrum communication system operating in the presence of both time and frequency-selective fading channel is presented. The receiver is a binary noncoherent matched-filter FFH-SS system with square-law combiner. The probability of error to the variations of the parameters such as signal-to-noise ratio, selectivity of a channel, and power ratio is derived with the use of diversity concept without considering the data rate. The analysis of the data for probability of error shoves that the performance of FFH-SS system in time-selective fading channel is better than in frequency-selective fading channel.

• The Journal of the Acoustical Society of Korea
• /
• v.3 no.2
• /
• pp.13-22
• /
• 1984

A surface acoustic wave signal processing device using the silicon surface state is presented and shown capable of storing a reference signal and later correlating another signal with the stored reference. The device memory consists of the storage of the spatial 2k pattern of an acoustic wave as stored charges in the surface state of silicon surface. Results of experiments are presented which characterize the operation of device. Simpliied models for charging process and nonlinear acoustoelectric interactions based on consideration of single surface state at the surface of silicon The validity of simplified model has been qualitatibely confirmed with experimental results and the application of this device to aprogrammable matched filter of communication is considered.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.14 no.11
• /
• pp.947-952
• /
• 2001

In this paper, a wideband SAW convolver using a parabolic horn waveguide was designed and its characteristics were investigated. The convolver was made with parabolic horn waveguide at compression ratio 9:1 for reducing propagation loss and for improving convolution efficiency between two input IDTs of center frequency 193.78 ㎒. The SAW convolver utilizing acoustic nonlinearities of piezoelectric material demonstrated that it can provide large S/N ratio and can be use for programmable matched filter(PMF) in spread spectrum communication system.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.23 no.3
• /
• pp.401-408
• /
• 1986

In optical pattern recognition, incorrect discrimination may result from a relatively high cross correlation peak between similary shaped objects. In this paper, a new modified matched CGH(computer generated hologram) filter is proposed for reducing the cross-correlation without reducing the autocorrelation. Computer simulation and experimental results show that this new method can be used efficiently for optical Korean alphabets recognition. The signal to noise characteristics are analyzed on the correlation distdribution diagram.