• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.940-949
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• 1998

The paper proposes an effective mechanism hiring the adaptive buffer control schemes on the mobile seceiver's side that can resolve the problems of delay spikes caused by the handover process onthe cell boundaries when they transmit real-time moving images through the high speed wireless channels. to confirm the effectiveness of the proposed schemes, we have modeled the characteristics of the random errors on the wireless channels, the burst errors and that of the transmission delay by the handover. We also compared the rate of the delay-adaptation of the receive buffers caused by the delay and delay spikes. the comparison was done by testing the suggested schemes against the existing schemes by applying tehm to the packet delay model. We also could identify the noticable reduction of the casesof buffer delay and overflow compared with the conventional schemes, by applying the suggested algorithm to the video image compressed by H.263.

• Journal of IKEEE
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• v.23 no.2
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• pp.571-579
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• 2019

Visible light communication (VLC) performs illumination and communication simultaneously, thus it is important to prevent the flicker due to the optical power variation during data transmission and at the same time to have dimming control capability. In this paper, we used Manchester code for flicker-prevention and dimming control. In the transmitter, the duty factor of the Manchester code was used for controlling the LED illumination. In the receiver, the edge-spike signals of an RC-high pass filter were used for recovering the Manchester code while preventing the adjacent noise light. In experiments, the LED light was kept flicker-free and the average optical power was controlled in the range of 8~68 % of the continuous wave (CW) LED light by changing the duty factor of the Manchester code.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.671-680
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• 2009

We performed a study to obtain kinematic data on the characteristics of spike serving techniques used by volleyball players, including other basic data that will be useful for in-field applications. We used three-dimensional videography to compare good tough serves and serve errors. The subjects were 3 left attackers whose spike serves were videographed (60 fileds/s). The three-dimensional coordinates were calculated using the direct linear transformation method and then analyzed using the Kwon 3D software program version 3.1. There was no difference in time elapsed. However, the vertical displacement of the center of body mass(CM) differed between the 2 types of serves: in successful serves, the CM tended to be lower, as did the maximum ball height at the time of hitting. Further, the higher the level of the hitting hand was at the moment of impact, the higher was the likelihood of scoring points. In good serves, the players tended to accelerate their CM movement just before jumping to hit the ball and descend rapidly at the moment of hitting. The hand speed along with ball velocity during the impact was proven to be higher in successful serves. Moreover, in successful serves, the shoulder angles increased to a greater extent while the elbow angles were maintained constant. This possibly resulted in faster and more precise serves. An important observation was that the angle of trunk inclination during the jump did not increase with the swing of the shoulders, muscle tendon complex.

• Analytical Science and Technology
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• v.16 no.6
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• pp.450-457
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• 2003

The determination of uranium and its isotopes in spent nuclear fuels by isotope dilution mass spectrometry (IDMS) has been studied. The spent fuel samples were dissolved in 8 M $HNO_3$ or its mixture with 14 M $HNO_3-0.05M$ HF. The dissolved solutions were filterred on membrane filter with $1.2{\mu}m$ pore size. The uraniums in the spiked and unspiked sample solutions were quantitatively adsorbed by anion exchange resin, AG 1X8 and eluted with 0.1 M HCl. The contents of uranium and its isotopes ($^{234}U$, $^{235}U$, $^{236}U$ 및 $^{238}U$) in the spent fuel samples were determined by isotope dilution mass spectrometric method using $^{233}U$ as spike. The spike reference solution was standarized by reverse isotope dilution mass spectrometry (R-IDMS) using natural and depleted uranium. The results from IDMS were in average relative difference of 0.34% when compared with those by the potentiometric titration method.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.4
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• pp.277-282
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• 2020

This study was initiated to find a way to resolve electronic equipment as it could be affected by multiple environments. The effect of setting the exponential constant wave (iExp) in the telescopic cascade comparator to the SET (Single Event Transient) environment was tested. In this paper, the radio wave delay was measured at 0.46 ㎲ and the gain at 0.713 in the telescopic cascade comparator without setting the SET situation. FET T0 (M6) was measured to have a large spike at 11㎲ to 15㎲ in the telescopic cascade comparator entering the SET situation. FET T1 (M5) has shorted output signals from 10 ㎲ to 16 ㎲. FET T2 (M3) represented a shorted output signal, and FET T3 (M4) measured the output waveform in the form of a large spike waveform. The FET T4 (M1) and FET T5 (M2) are spiky signals. And at all FETs, the propagation delay was changed from 0.45㎲ to 0.54㎲. In summary, The FET element in the telescopic cascade comparator in SET situation was measured to be greatly affected.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.72-72
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• 2017

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.63-64
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• 2014

본 논문에서는 Saliency map과 Max Filter를 이용한 영상의 자막영역을 추출 한다. Saliency map은 눈에 띄는 영역, 즉 영상에서 주변영역에 비해 밝기 차이가 심한 영역과 윤곽선에 대한 특징이 강한 영역을 돌출하는 것을 말하며, MaxFilter는 중심 픽셀을 최대 윈도우 값을 사용하는 것으로 극단적인 Impulse Noise를 제거하는데 효과적이며 특히 어두운 스파이크를 제거하는데 유용하게 사용된다. 이 두 가지의 특징들을 이용하여 영상의 자막 영역을 추출한다.

• Proceedings of the KIPE Conference
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• 2018.11a
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• pp.199-200
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• 2018

본 논문에서는 양방향 스위치 구조의 AC-AC 컨버터 토폴로지를 제안한다. 또한 데드타임 구간에서의 전류 패스를 확보하여 단락 현상 및 전류 스파이크 현상을 방지할 수 있는 커뮤테이션 기법을 제안한다. 전류 패스에 따른 회로를 각각 제시하고, 각 스위치의 스위칭 패턴을 유도한다. 모의 실험을 통해 제안된 커뮤테이션 기법의 타당성을 검증하였다.

• 한국해양학회지
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• v.18 no.2
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• pp.117-124
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• 1983

Pizza's synthetic model, a modified Wiener filter method, was tested to establish the procedure of desirable interpretive wavelet extraction and its application to the marine seismic exploration using several approaches with a real offshore seismic data of the southeast Asia. Noise spectrum acquisition is difficult and any assumptions for it do not produce interpretive wavelets as good as synthetic model result by Piazza (1979). however the resolution could be improved with spiking deconvoultion and following zero phase bandpass filter, and the testing procedure and evaluatttion of results can hopefully contribute in future study and practical evaluation of Piazza's method.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1132-1140
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• 1997

In many vision tasks of the major obstacles is the specular highkight of smoth objects, which causes a misinterpretation of objects.This paper presents an dffcient algorithm for highight detection and object reconstruction, blsed on the theory of photometric stereo in which the location of highilight changes as the position of illumination source changes.Two images, referred to as base image and reference image.are sequentially taken with two different positionhs of the two images.The difference image is thresholded to detct the specular spike of the highlight.Then the specu-lar lobe around the specular spike is detected to reconstruct the object.The proposed algorithm can be applied to metals and dielectrics, regardlless of the surface chracteristics.This method can also be aplied to the case when the background is brighter than the object.