• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.57-63
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• 2012

Effective use of stethoscope is very important for primary clinical diagnosis for the increasing cardiovascular and respiratory disease. This study developed the contact vibration sensor using piezopolymer film which minimizes the ambient noise, and signal processing algorithm was applied for providing better auscultation sounds compare to the existing electronic stethoscopes. Especially, low frequency heart sounds were acquired without distortion, and the quality of lung sounds were improved. Also, auscultating sounds could be transmitted using bluetooth, which made possible to be used for the u-healthcare environment. Results of this study, auscultation of heart and lung sounds, could be applied to the convergence industry of medical and information communication technology through remote diagnosis.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.479-479
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• 2018

하천의 수심, 유속, 하상경사, 하상재료, 만곡도 등과 같은 물리적 특성에 따라 생물서식처로서 다양한 특성을 나타내고 그 특성들에 의해 서식처의 유형을 구분할 수 있다. 이러한 서식처 유형에 따라 수중음향의 특성이 달라지며, 수중음향의 서식지의 양적 표시자로서 잠재력으로 인해 최근 많은 연구들이 시도되고 있다. 본 연구에서는 인공적인 영향을 적게 받은 자연하천으로 양양 남대천 12개 지점을 대상으로 하여 서식지의 형태에 따른 수중음향과 하천의 수리적 인자에 따른 관계를 파악하고자 하였다. 서식처 유형으로는 빠른 유속에 얕은 수심을 가지고 있는 여울(riffle), 수심이 깊고 유속이 느린 소(pool), 낙차가 있는 계단형 여울(step riffle)에 대해 조사하였다. 수중배경음은 여울과 계단형 여울이 유사하게 나타났으며 소는 상대적으로 낮은 배경음을 나타내었다. H2, H4, H5, H9, H10 지점은 여울 형태로 유속에 따라 H2, H5, H4, H9 지점 순으로 음압레벨이 낮아지는 경향을 보였으며, H10지점은 H9, H4 지점에 비해 낮은 유속임에도 높은 음압레벨을 보였다. 이는 H10 지점의 하상이 조도가 매우 큰 전석으로 이루어져 나타나는 현상으로 판단된다. H3, H6, H7, H8, H12 지점은 소 형태로 H12 지점을 제외하고 대체로 낮은 음압레벨을 보였으며, H3과 H6지점에서는 저주파수에서 높은 음압레벨을 보였다. 이는 수심이 깊은 경우 상류의 저주파수의 음파가 잘 전달되기 때문으로 판단된다. H1과 H11지점은 계단형 여울로 낮은 수심에서 빠른 유속을 가진 H11지점과 느린 유속을 가진 H1 지점에서 대체로 높은 음압레벨을 나타내었다. 이는 낙차에 의한 수중음향 발생에 의한 것으로 판단된다. 세 가지 유형에 따른 수중 음향을 비교하였을 때 음압레벨은 계단형 여울, 여울, 소 순서로 높게 나타났다. 결과적으로 수중음향이 서식처의 수리적 특성에 따라 다양한 특성을 나타내고 있으며, 이를 통해 생물서식처를 평가하기 위한 새로운 방법으로 수중음향의 활용 가능성을 제시하였다.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1173-1176
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• 1999

전력계통에서 발생하는 저주파 동요에 대해서 가장 효과적인 제동력 향상방안으로 알려진 PSS의 최적 설치지점을 결정하기 위하여 NSE(Normalizing Speed Eigenvectors), SPF(Speed Participation Factors), TFR(Transfer Function Residues) 및 주파수 응답법을 각각 비교분석 하였다. 분석결과 SPF는 제어/입력 행렬을 포함하지 않는 상태행렬만을 고려하기 때문에 PSS의 제어특성을 반영하지 못하는 단점이 있었으며 TFR은 여자기 이득에 민감하여 최적위치 선정에 있어서 문제점을 보였다. 본 연구에서는 SPF법을 이용하여 PSS 설치 후보지를 선정하고 이들 후보지에 대해서 TFR법과 주파수 응답법으로 최적의 발전기를 결정하도록 하였으며 PSS를 설치하여 그 효과를 검증하였다.

• Korean Journal of Construction Engineering and Management
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• v.15 no.2
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• pp.12-22
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• 2014

Recently, many people have been damaged seriously by construction noise. Accordingly, there have been increased the complaints and disputes. These complaints should be controlled strictly. Otherwise there could be delays or stops of project and losses of time and money. For this reasons, the Korean government is trying to convert from depending on the soundproof wall to noise control system focusing on noise sources. However, it is difficult to control the noise which is generated from construction site because construction equipment has very high noise level and construction noise generates temporarily and irregularly. Also, people do not know how much low frequency affect human body adversely because they cannot perceive low frequency noise easily. Hence, recently developed countries have conducted the research on the low frequency noise which damages on human physically and mentally. However, passive noise control is insufficient to reduce the low frequency noise, but only efficient to lower the high frequency noise. Thus, an approach which can complement limitations of passive noise control is needed. Therefore, the purpose of this research is to suggest the noise management model using active noise control on construction site. Also, ANC simulation has been conducted to examine its applicability on construction equipment. As a result, it is expected that there will be a reduction of construction noise and demages, as well as both mental and physical damages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.1
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• pp.49-57
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• 2002

The possibility of a transmission noise reduction of piezoelectric smart panels using piezoelectric shunt damping is experimentally studied. Piezoelectric smart panel is basically a plate structure on which piezoelectric patch with shunt circuits is mounted and sound absorbing materials are bonded on the surface of the structure. Sound absorbing materials can absorb the sound transmitted at mid frequency region effectively while the use of piezoelectric shunt damping can reduce the transmission at resonance frequencies of the panel structure. To be able to reduce the sound transmission at low panel resonances, piezoelectric damping using the measured electrical impedance model is adopted. Resonant shunt circuit for piezoelectric shunt damping is composed of register and inductor in series, and they are determined by maximizing the dissipated energy throughout the circuit. The transmitted noise reduction performance of smart panels is investigated using an acoustic tunnel. The tunnel is a tube with square crosses section and a loud-speaker is mounted at one side of the tube as a sound source. Panels are mounted in the middle of the tunnel and the transmitted sound pressure across panels is measured. Noise reduction performance of a smart panels possessing absorbing material and/or air gap shows a good result at mid frequency region but little effect in the resonance frequency. By enabling the piezoelectric shunt damping, noise reduction of 10dB, 8dB is achieved at the resonance frequencise as well. Piezoelectric smart panels incorporating passive method and piezoelectric shunt damping are a promising technology for noise reduction in a broadband frequency.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.211-217
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• 2012

Conventional GrabCut algorithm is semi-automatic algorithm that user must be set rectangle window surrounds the object. This paper studied automatic object detection to solve these problem by detecting salient region based on Human Visual System. Saliency map is computed using Lab color space which is based on color opposing theory of 'red-green' and 'blue-yellow'. Then Saliency Points are computed from the boundaries of Low-Frequency region that are extracted from Saliency Map. Finally, Rectangle windows are obtained from coordinate value of Saliency Points and these windows are used in GrabCut algorithm to extract objects. Through various experiments, the proposed algorithm computing rectangle windows of salient region and extracting objects has been proved.

• Journal of IKEEE
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• v.22 no.1
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• pp.21-28
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• 2018

In this paper, we have developed the intellectual kegel trainer with the bio-feedback. The one is smart health care system that can treat an evacuation impediment and urination polyuria with the low frequency stimulation module. Then this detects the shrinkage power of the pelvis muscles and correlates an smart phone entertainment application program for the users. In order to recover the function of pelvic muscles, we use the intellectual smart health care trainer with several biofeedback function. Such a trainer makes to strength the weakness pelvic muscles by biofeedback training and get exercise the pelvic muscles in physical suppress. The biofeedback training against the physical suppress can have strengthen the pelvic muscles and can display the operation graph of strengthen movement in monitor. Finally, It can be ensured the safety through EMI and performance test.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.1
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• pp.88-95
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• 2017

In this paper, we present a saliency detection method using entropy weight and Weber contrast in the wavelet transform domain. Our method is based on the commonly exploited conventional algorithms that are composed of the local bottom-up approach and global top-down approach. First, we perform the multi-level wavelet transform for the CIE Lab color images, and obtain global saliency by adding the local Weber contrasts to the corresponding low-frequency wavelet coefficients. Next, the local saliency is obtained by applying Gaussian filter that is weighted by entropy of wavelet high-frequency subband. The final saliency map is detected by non-lineally combining the local and global saliencies. To evaluate the proposed saliency detection method, we perform computer simulations for two image databases. Simulations results show the proposed method represents superior performance to the conventional algorithms.

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.49-54
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• 2020

The purpose of this study was to investigate the correlation between sports incidence and heart rate variability in nationa lfemale judo athletes. Participants measured heart rate variability using the Autonomic Nervous System(SA-6000). Based on the average incidence of injury, sports injury incidence was classified into upper and lower groups. In addition, Pearson's Product Moment Correlation was performed to examine the correlation between the independent T-test, the number of sports injuries, and the heart rate variability. Heart rate variability was significantly different in total power and low frequency, and there was also significant difference in otal power and low frequency in the correlation analysis of heart rate variability according to the number of sports injuries. These data are expected to be useful as basic data for developing prevention injury programs.

• Journal of the Korea Computer Industry Society
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• v.8 no.1
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• pp.23-28
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• 2007

There are many modern's overwork. excessive drinking, carriage that give stress in muscle by smoking. Because time that sit long by carriage is much. if myalgia beats widower on muscle rheumatism or union formation inflammation, core ache, there is congealment and is painful. Muscle itself is no military register change and rheumatism change shows in areolation of muscle film or muscle nerve sheath etc. that union tissue's inflammation case is around the muscle. It is typical rain joint sex rheumatism. Can assume in case of made work that do not get used to extreme exercise or body perforce. Special quality of do waveform and supersonic waves stimulation processing plant which frequency that is established in research that do Iroin is continued without change is available embodiment according to patient's state variously by series mode through mode frequency waveform, 10 modes, 25 modes, 50 modes etc. Sample that can decide basis standard for supersonic waves through an experiment, low frequency treatment equipment standard for low frequency equipment. supersonic waves treatment equipment that float in city adjusting establishment naturally establish.