• 한국응급구조학회지
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• 제14권3호
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• pp.71-81
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• 2010

Purpose: To minimize an interruption in chest compression, reduce the hands-off time, the American Heart Association has recommended the ratio of chest compression to ventilation ratio to 30:2 from 2005 CPR guideline to 2010 CPR guideline. However, current studies have shown that the hands-off time was > 10 seconds with that method. For this reason, we devised new CPR method that a ventilation to chest compression ratio of 2:30 to reduce pt assessment time and skipped the assessment step of carotid artery pulse would be a more effective way to reduce the hands-off time & the time to set the CPR. According to the more detailed purpose are listed below. 1) We would like to confirm efficiency of a ventilation to chest compression ratio of 2:30 than a chest compression to ventilation ratio of 30:2 to reduce the hands-off time & the time to set the CPR. 2) We would like to evaluate possibility of increasing for chest compression accuracy of a ventilation to chest compression ratio of 2:30 than a chest compression to ventilation ratio of 30:2 3) We would like to evaluate possibility of increasing for ventilation accuracy of a ventilation to chest compression ratio of 2:30 than a chest compression to ventilation ratio of 30:2 Methods: According to 2005 American Heart Association Guidelines, 60 paramedic students(20 students X freshmen, sophomore, junior) performed 5 cycles of 3~ chest compressions : 2 ventilations after A, B, C evaluation with Laerdal Resusci R Anne SkillReporters. After 5 minutes rest, the 60 students performed 5 cycles of 2 ventilations : 30 chest compressions after A, B evaluation with the manikins between 13 and 17 September 2010. The short reports including speed & accuracy of chest compression, respiratory, CPR cycle were gained from the manikins. Hands-off times were measured by assistants. Results: Recently, the importance of high quality CPR was emphasized in order to perform the CPR faster and more accurate. To find out improving the conventional CPR method, we switch the procedure of the compression and the ventilation. By switching the procedure back and forth, we are able to compare the effectiveness of CPR between two type of CPR method which are 2:30 and 30:2 methods. 2:30 is that the breaths is delivered twice, first and perform 30 compressions while 30:2 perform 30 compressions first and give 2 breaths followed by the ABC method. Also, we verify the effectiveness of the hands off time, compression accuracy of the compression through the comparison of the two procedure as mentioned earlier. Consequently research verified that 2:30 is the efficient by providing faster set up delivering more accurate chest compression. Conclusion: 2:30 can minimize a time delay from cardiac standstill until starting the chest compression. In addition, hands-off time which is an interruption in chest compression can be shortened by 2:30 method, which result to effective oxygenation of coronary artery & maintenance of the bloodstream. Once again, performing the 2:30 method provide lessen hands off time and increase the accuracy of the chest compression.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.419-426
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• 2008

As pulse detonation engine(PDE) does not need compression mechanisms such as compressors because self-sustained detonation waves are able to compress propellant gases by their incident shock waves, the PDE can have a simple straight-tube structure. In this study, we propose an autonomous driving valve system of the PDE, which fill premixed gases into the PDE tubes at high frequency with high mass flow rate. The proposed valve is composed of only three parts: a piston, a cylinder, and a spring. This valve system can produce intermittent flow at high mass flow rate, and also can keep stable reciprocal motion by using the propellant-gas enthalpy. When the cylinder content product is assumed to be constant, experimental results of the mass flow rate were approximately equal to the calculation model. We confirmed the autonomous driving valve performance by experiments, and concluded that this extremely simple valve with no electrical power and controller can be used as the PDE propellant supply system.

• 대한한방내과학회지
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• 제11권2호
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• pp.128-136
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• 1990

I Studied some important medical literatures inorder to examine the cause & syndrome of diffuse fluid-retention syndrome and found out some facts as follows ; 1. cause of diffuse fluid-retention syndrome is Hwang Je Nae Kyong(黃帝內經) and so forth six kinds of medicine books are reffered sudden thirst of intestin and stomark cause of disease Golden chamber(金?要略) and so forth fifteen kinds of medicine books are reffered fluid water promote obscesses atributide at four extrenities and unable hidrosis cause of disease Elementary cause for medicine(醫學入門) and so forth kinds of book medicine books are reffered water in four extrenities cause of disease. The classified Medical Records of Famous physicians(名醫類安) reffered rest at wetness earthly cause of disease. 2. syndrome of diffuse fluid-retention syndrome is Golden chamber and so forth nineteen kinds of medicine books are reffered compression and pain of body syndrome of disease. Hwang Je Nae Kyong(黃帝內經) and so forth seven kinds of medicine books are reffered pulse ; the liver-pulse is soft and powder syndrome of disease. The classified Medical Records of Famous physicians(名醫類安) and so forth two kinds at medicine book are reffered general syndrome of disease. Today is reffered edema of four extremites syndrome of disease. The cause & syndrome of diffuse fluid-retention syndrome obtained was as follows ; cause of diffuse fluid-retention syndrome is fluid water promote abscess attributide at four extremities and unable hidrosis and compression and pain body is main syndrome and hyperhidrosis, vertigo, edema of four extremities alternating episodes of chills and fever can guan pulse is sunken and slippery and both chi wiry are represented syndrome of diffuse fluid-retention syndrome.

• 한국정보통신학회논문지
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• 제24권9호
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• pp.1215-1223
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• 2020

최근 서울 경기를 비롯한 전국에서 국지성 집중호우, 태풍 등 악천후 관련 자연재해가 증가함에 따라 이에 대한 방재 및 물관리 대책이 필요한 실정이다. 이러한 수재해를 관측하기 위해 사용되는 우량계는 지상의 강우를 연속적·직접적으로 측정할 수 있는 장점이 있는 반면, 우량계 미설치 영역에 대한 공간적인 강우 분포를 정확하게 제공할 수 없다. 이러한 문제를 해결하고자 강수의 공간분포를 측정할 수 있는 전자파 기반 센서인 전파강수계(EWRG, Electromagnetic Wave Rain Gauge)를 개발하였다. 본 논문에서는 전파강수계의 FPGA 기반 신호처리 설계 방법을 제안한다. 전파강수계의 신호처리는 크게 LFM 파형의 ADC 및 DDC와 펄스압축, 상관 계수 및 강수 파라미터 산정으로 설계하였다. 본 연구를 통해 LFM 파형과 펄스압축 신호를 이론적으로 분석하였으며, 전파강수계 신호처리 설계를 위해서 FPGA 기반의 신호처리 설계 및 검증을 수행하였다.

• 한국지반환경공학회 논문집
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• 제15권4호
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• pp.37-41
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• 2014

펄스동전기법은 점토성-사질토에서 탈수화 공정을 효율적으로 진행하기 위해 제안되었다. 제안된 동전기법은 점토성-사질토에서 토양 안정성의 증진을 위해 전류 흐름에 따르는 유체의 이동에 의한 탈수화 공정을 진행하는 것이다. 제안된 동전기법의 성능을 확인하기 위해 제작된 샘플은 총 7일간에 점진적으로 압력을 증가시켜 30 psi($2.11kgf/cm^2$)의 최종압력으로 압축과정을 거쳐 완성되었다. 기존의 연속적인 처리와 펄스방식으로 처리하는 공정을 비교하여 각각의 특성을 관찰하였다. 각각의 테스트는 48시간 동안 3 V/cm의 전압 경사 조건으로 연속적인 처리공정과 48시간 동안 총 8시간씩 3회에 걸쳐 전기를 차단하는 펄스방식으로 진행하였다. 그 결과, 펄스방식의 효율이 연속처리방식의 효율과 비슷한 것으로 나타났고 펄스방식이 연속처리방식보다 전력소비가 약 50 % 감소로 그 경제성을 입증하였다.

• Current Optics and Photonics
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• 제4권4호
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• pp.310-316
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• 2020

We propose and experimentally demonstrate an all-optical radio frequency (RF) spectrum broadening system based on time compression. By utilizing the procedure of dispersion compensation values, the frequency domain is broadened by compressing the linear chirp optical pulse which has been multiplexed by the radio frequency. A detailed mathematical description elucidates that the time compression is a very preferred scheme for spectrum broadening. We also report experimental results to prove this method, magnification factor at 2.7, 8 and 11 have been tested with different dispersion values of fiber, the experimental results agree well with the theoretical results. The proposed system is flexible and the magnification factor is determined by the dispersion values, the proposed scheme is a linear system. In addition, the influence of key parameters, for instance optical bandwidth and the sideband suppression ratio (SSR), are discussed. Magnification factor 11 of the proposed system is demonstrated.

• 한국항공우주학회지
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• 제42권10호
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• pp.858-869
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• 2014

대부분의 항공우주 추진은 정압 Brayton 사이클에 기초하고 있으나 성능 향상을 위한 압력비 증가는 기계적 한계에 직면하고 있다. 지난 십여 년간 고속 추진에 적합한 연소방식으로 기대 받은 데토네이션 추진이, 최근에는 추진기관과 동력 장치의 열효율을 획기적으로 증대시켜 줄 수 있는 "game-changer"로 연구되고 있다. 즉, 데토네이션 파에 수반하는 강한 충격파의 압축 효과는 기존의 압축 방식에서 얻기 힘든 열효율을 증가시키는 것으로 여겨진다. 본 논문에서는 펄스데토네이션엔진의 최신 기술 동향과 더불어 정적연소에 기초한 압력증가연소 체계의 연구 동향에 대하여 소개할 것이다.

• 대한의용생체공학회:의공학회지
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• 제23권1호
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• pp.61-72
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• 2002

본 논문에서는 펄스 압축 방식을 사용하여 기본주파수 성분을 효과적으로 제거하는 새로운 고조파 영상 기법을 제안한다. 제안된 기법에 의한 시스템은 가중 쳐프 신호를 송신하고 각 어레이 소자에 수신된 RF 샘플은 송신신호의 고조파 성분에 정합된 상관기를 통과함으로써 고조파 성분만을 선택적으로 펄스 압축한다. 이 때. 기본주파수 성분과 고조파 성분의 상호상관 값은 -50㏈ 이하로 억제하였다. 제안된 기법은 한번의 송수시 과정으로 기본주파수 성분을 효과적으로 제거하여 프레임 율이 기존의 펄스 반전 방식보다 우수한 방식과 우수한 해상도와 신호 대 잡음비 (SNR : Signal to Noise Ratio)를 갖는 고조파 영상을 구현하기 위해 펄스 반전을 적용한 후 펄스 압축을 수행하는 방식으로 구성된다 일반적인 펄스 송신 방식에서는 고조파 성분은 송신음압의 크기가 어느 임계값 이상이 되면 더 이상 증가하지 않고 포화되기 때문에 SNR이 제한되는 단점이 있다. 그러나 제안된 기법은 송신 가중 쳐프 신호의 길이를 늘림으로써 고조파 영상의 SNR을 임의로 증가시킬 수 있다 새로운 시스템의 성능을 컴퓨터를 이용한 모의실험과 실제실험을 통하여 검증하였다

• 한국응급구조학회지
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• 제12권3호
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• pp.43-53
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• 2008

Purpose : This study was designed to examine physiological changes in the body of rescuers conduct CPR according to the 2005 new guideline from American Heart Association. The ratio of artificial respiration has changed from 15 : 2 into 30 : 2 in 2005. The researcher tried to know the correlation between the physiological changes and the accuracy of CPR. Method : The examinees of this study were 26 students (Dept. of Emergency Medical Service). After the training, participants conducted 10 minute CPR and soon after the CPR, their vital signs were checked, and lactic acid and concentration of ammonia were analysed from their blood samples. Questionnaires to ask their subjective fatigue level were filled out after blood samples and 10 minute - CPR was performed. Results : 1) After the CPR, concentrations of ammonia were $149.71{\mu}{\ell}/d{\ell}$ and $162.17{\mu}{\ell}/d{\ell}$ in 15 : 2 and 30 : 2, respectively. The number was higher in 30 : 2 but it wan not statistically meaningful (p = .493). Log value of lactic acid was a little higher in 30 : 2 with 42 log($mmol/{\ell}$) and 54 log($mmol/{\ell}$) in 15 : 2 and 30 : 2, respectively but it was not statistically meaningful (p = .113). 2) Blood pressure in 15 : 2 and 30 : 2 were 118.50 mmHg and 125.08 mmHg while pulse in two different cases were 96.14 and 97.25, showing no statistically significant differences (blood pressure : p = .155, pulse : p = .841). 3) Subjective fatigue was a bit high in 30 : 2 with 5.93 and 6.92 points in 15 : 2 and 30 : 2 respectively but it was not statistically meaningful (p = .142). 4) In the 10 minute CPR, respiration accuracy was 96.21% in 15 : 2 and 94.79% in 30 : 2. There was no statistical significances between the two(p = .225). In the meanwhile, chest compression accuracy was 92.57% in 15 : 2 and 91.83% in 30 : 2. From the beginning to the end of chest compression, there showed no difference(p = .425). the type of CPR did not influence upon the accuracy of chest compression(p = .756). Conclusion : In the CPR conducted by skilled rescuers for 10 minutes, there were no statistically meaningful differences between 15 : 2 and 30 : 2 in the concentration of fatigue element in a blood, subjective fatigue, vital signs and accuracy of CPR. Therefore, 30 : 2 CPR recommended by American Heart Association need to be recommended and performed in scene size up.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권7호
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• pp.332-338
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• 2005

PD(Partial Discharge) signal emitted from PD sources has their intrinsic features in the region of time and frequency STFT(Short Time Fourier Transform) shows time-frequency distribution at the same time. 2-Dimensional matrices(33$\times$77) from STFT for PD pulse signals are a good feature vectors and can be decreased in dimension by wavelet 2D data compression technique. Decreased feature vectors(13$\times$24) were used as inputs of Back-propagation ANN(Artificial Neural Network) for discrimination of Multi-PD sources(air discharge sources(3), surface discharge(1)). They are a good feature vectors for discriminating Multi-PD sources in the air.