• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.3
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• pp.389-396
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• 1986

A pulsed ultrasonic doppler flowmeter for mesurements of velocity profils in man is described. The device projects a beam of ultrasound in burst of 570 ns duration at 3.5 MHz. The back-scattered signals are processed to produce a signal oxrresponding to the mean velocity over a small region of the flowing stream. The observation range of 112mm is divided into 128 depth channels. The size of this sample volume determines the flowmeter sensitivity and accuracy. The device uses a quadrature detector to detect the direction of the moving target(hemoglobin). The main feature of the novel instrumnet is its simple hardware structure due to sequential signal processing.

• Annual Conference of KIPS
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• 2002.04a
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• pp.213-216
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• 2002

멀티 채널 오디오 시스템 및 입체음향 기술이 대중화 되면서 오디오 데이터의 저장 및 재생 방법에 있어서 실감 현장 음향을 고려하는 것이 일반화되었다. 이 논문에서는 구조화 오디오 데이터 형식 [1]을 이용해 불필요한 데이터 공간을 제거하고, 거기에 입체 음향 기술을 적용시켜 효과적인 오디오 데이터 처리 방법을 제시하고자 한다. 우리는 구조화 오디오 데이터 형식을 개념적으로 명백히 하기 위해 재사용 가능한 "소리 객체"를 사용하였다. 소리 객체는 오디오 데이터를 처리하기위한 녹음된 소리 샘플의 기본 단위로서 소리객체에 3D 위치 속성이나, 필터 속성을 지정해 소리를 변화 시킬 수 있다.

• Annual Conference of KIPS
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• 2001.10a
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• pp.167-170
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• 2001

제안하고자 하는 오류 제어는 멀티미디어 응용 개발 프레임워크에서 오류 발생시 오류를 하나의 미디어로 취급한다. 본 논문에서는 멀티미디어 응용 개발 프레임워크에서 다채널 방식을 사용한다. 다채널 방식이란 미디어 데이터 별로 별도의 채널을 할당하여 채널별로 단일 미디어 정보를 순서대로 전송함으로써 동일 미디어 데이터는 순서가 변할 우려가 없다. 오류도 오류 발생시 순서대로 전송한다. 그러나 이러한 다 채널 방식의 미디어 동기화는 미디어 간 동기화 문제를 유발시킨다. 미디어 간 동기화를 위해서 미디어 채널과 제어/오류제어 채널을 사용한다. 제어 채널은 동기화 정보 외에 오류 동기화 정보, 트래픽 정보, 세션의 유지 정보, 발언권 변경 정보 등과 같은 정보를 전송하는 채널이다.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.991-1000
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• 2020

We propose a content-based image retrieval system that uses a combination of completed local binary pattern (CLBP) and color autocorrelogram. CLBP features are extracted on a multi-resolution multi-direction filtered domain of value component. Color autocorrelogram features are extracted in two dimensions of hue and saturation components. Experiment results revealed that the proposed method yields a lot of improvement when compared with the methods that use partial features employed in the proposed method. It is also superior to the conventional CLBP, the color autocorrelogram using R, G, and B components, and the multichannel decoded local binary pattern which is one of the latest methods.

• Geophysics and Geophysical Exploration
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• v.23 no.1
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• pp.13-21
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• 2020

The acquisition and processing of long-offset data are essential for imaging deep geological structures in marine seismic surveys. It is challenging to derive an accurate subsurface image by employing conventional data processing to long-offset data owing to the normal moveout (NMO) stretch and non-hyperbolic moveout phenomena induced by seismic anisotropy. In 2017, the Korea Institute of Geoscience and Mineral Resources conducted a simultaneous two-dimensional multichannel streamer and ocean-bottom seismic survey using a 5.7-km streamer and an ocean-bottom seismometer to identify the deep geological structure of the Ulleung Basin. Herein, the actual geological subsurface structure was obtained via the sequential iterative updating of the velocity and anisotropic parameters of the long-offset data obtained using a multichannel streamer, and anisotropic prestack Kirchhoff migration was performed using the updated velocity and anisotropic parameters as input parameters. As a result, the reflection energy in the long-offset traces, which showed non-hyperbolic moveout owing to seismic anisotropy, was well aligned horizontally and NMO stretches were also reduced. Thus, a more precise and accurate migrated image was obtained, minimizing the distortion of reflectors and mispositioned reflection energy.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.102-110
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• 2017

In this paper, we have implemented an real-time adaptive feedback cancellation(AFC) algorithm that can be applied to multi-channel digital hearing aid. Multichannel digital hearing aid typically use the FFT filterbank based Wide Dynamic Range Compression(WDRC) algorithm to compensate for hearing loss. The implemented real-time acoustic feedback cancellation algorithm has one integrated structure using the same FFT filter bank with WDRC, which can be beneficial in terms of computation affecting the hearing aid battery life. In addition, when the AFC fails to operate due to nonlinear input and output, the reduction gain is applied to improve robustness in practical environment. The implemented algorithm can be further improved by adding various signal processing algorithm such as speech enhancement.

• 전자공학회논문지 IE
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• v.43 no.1
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• pp.16-24
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• 2006

This paper is aimed to develope of an integrated BCI(Brain Computer Interface System) that make possible for simultaneous multichannel data process and used extra cellular neural activity from the vestibular system instead of electroencephalogram signals for more precision control. The electrical properties pre-amplifier are 47.6 dB of gain, 0.005 % of distortion at 100 Hz, 12M$\Omega$ of input impedance. Window discriminator used two CPU with difference role to increase processing speed so that sampling frequency was 87 kHz. The designed window discriminator has more not only two times in signal resolution power but also ten times in error discrimination power than commericially available discriminator. The proposed method decreases 100 times in amount of integrated data then BCI system during 100 ms.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.671-676
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• 2016

This study is about design for the Rotational Instrument of the Industry factory which is used management safety and maintenance. We developed the multichannel vibration monitering system of the self-diagnosis for middle level CMS(Condition Monitoring System) market, and that system are new features to the expandability and flexibility. Normally one channel is used for treating one signal, but developed instrument can treat four channel with one signal processing card. One rack have redundant power supply and displace and it can check vibration measurement value in field without computer. Bearing fault detection is fundamental of vibration surveillance, but sometimes can not check with vibration velocity and acceleration. So it need the filtering and the amplitude modulation on the acceleration enveloping technology when irregular vibration is happened. We developed the vibration analysis instrument which is applied such technology. And the development prototype shows activated within the vibration error limit.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.75-91
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• 2023

In this study, we explore the use of ground penetrating radar (GPR) for the nondestructive survey of subsurface conduits, focusing on the challenges posed by multichannel environments. A key concern is the shadow regions created by conduits, which significantly impact survey results. The shadow regions, which are influenced by conduit position and diameter, hinder signal propagation, thereby making detection within these regions challenging. Using finite-difference time-domain numerical analysis, we examined the characteristics of conduit signals, which typically manifest in hyperbolic patterns. Particularly, we investigated three conduit arrangements: horizontal, vertical, and diagonal. Automatic gain control was applied to amplify the signals, enabling the analysis of variations in shadow regions and signal characteristics for each arrangement. In the horizontal arrangement, the proximity of the two conduits resulted in the emergence of a new hyperbolic pattern between the existing conduits. In the vertical arrangement, the lower conduit could be detected using hyperbolic signals on either side, but the detection was challenging when the upper conduit diameter exceeded that of the lower conduit. In the diagonal arrangement, signal characteristics varied based on the position of shadow regions relative to the detection range of the equipment. Asymmetrical signal patterns were observed when the shadow regions fell within the detection range, whereas the signals of the two conduits were minimally impacted when the shadow regions were outside the detection range. This study provides vital insights into accurately detecting and characterizing subsurface multichannel conduits using GPR-a significant contribution to the field of subsurface exploration and management.

• Journal of Biomedical Engineering Research
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• v.12 no.2
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• pp.113-120
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• 1991

This paper describes the implementation of a 3 channel ECG monitoring system. This system consists of an IBM-PC and simple accessory only. A PDTS (parallel data transmission system ) was designed to do monitor the data being operated with no effect and no exchange of software and hardware on the main transmission system in LOCAL mode. And it receives patient's ECG data from EPTS ( ECG processing and transmission system) of distant region. It provides on-line ECG waveform display, waveform storage, recall and editing the waveform. We have implemented the monitoring system by tw methods, and with system, we could directly monitor the EPTS and also receive the data from the remote ㅁe잉ion. This system was tested by experiments and examined its practical use.